Remove local author from contacts.

Bump schema version to match migrations

See merge request briar/briar!1084

.idea/codeStyles/Project.xml

@@ -39,6 +39,31 @@
     <JetCodeStyleSettings>
       <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
     </JetCodeStyleSettings>
+    <Objective-C-extensions>
+      <file>
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Import" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Macro" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Typedef" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Enum" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Constant" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Global" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Struct" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="FunctionPredecl" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Function" />
+      </file>
+      <class>
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Property" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Synthesize" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="InitMethod" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="StaticMethod" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="InstanceMethod" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="DeallocMethod" />
+      </class>
+      <extensions>
+        <pair source="cpp" header="h" fileNamingConvention="NONE" />
+        <pair source="c" header="h" fileNamingConvention="NONE" />
+      </extensions>
+    </Objective-C-extensions>
     <XML>
       <option name="XML_LEGACY_SETTINGS_IMPORTED" value="true" />
     </XML>

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/AndroidTorPlugin.java

@@ -32,9 +32,6 @@ import static java.util.concurrent.TimeUnit.MINUTES;
 @ParametersNotNullByDefault
 class AndroidTorPlugin extends TorPlugin {
 
-	// This tag may prevent Huawei's power manager from killing us
-	private static final String WAKE_LOCK_TAG = "LocationManagerService";
-
 	private final Context appContext;
 	private final RenewableWakeLock wakeLock;
 
@@ -55,7 +52,7 @@ class AndroidTorPlugin extends TorPlugin {
 				appContext.getSystemService(POWER_SERVICE);
 		if (pm == null) throw new AssertionError();
 		wakeLock = new RenewableWakeLock(pm, scheduler, PARTIAL_WAKE_LOCK,
-				WAKE_LOCK_TAG, 1, MINUTES);
+				getWakeLockTag(), 1, MINUTES);
 	}
 
 	@Override
@@ -87,4 +84,17 @@ class AndroidTorPlugin extends TorPlugin {
 		super.stop();
 		wakeLock.release();
 	}
+
+	private String getWakeLockTag() {
+		PackageManager pm = appContext.getPackageManager();
+		for (PackageInfo info : pm.getInstalledPackages(0)) {
+			String name = info.packageName.toLowerCase();
+			if (name.startsWith("com.huawei.powergenie")) {
+				return "LocationManagerService";
+			} else if (name.startsWith("com.evenwell.powermonitor")) {
+				return "AudioIn";
+			}
+		}
+		return getClass().getSimpleName();
+	}
 }

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidSystemModule.java

@@ -1,10 +1,13 @@
 package org.briarproject.bramble.system;
 
+import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
 import org.briarproject.bramble.api.system.SecureRandomProvider;
 
+import java.util.concurrent.Executor;
+
 import javax.inject.Singleton;
 
 import dagger.Module;
@@ -32,6 +35,13 @@ public class AndroidSystemModule {
 		return androidExecutor;
 	}
 
+	@Provides
+	@Singleton
+	@EventExecutor
+	Executor provideEventExecutor(AndroidExecutor androidExecutor) {
+		return androidExecutor::runOnUiThread;
+	}
+
 	@Provides
 	@Singleton
 	ResourceProvider provideResourceProvider(AndroidResourceProvider provider) {

bramble-android/witness.gradle

@@ -4,7 +4,6 @@ dependencyVerification {
         'com.android.tools.analytics-library:protos:26.3.2:protos-26.3.2.jar:50238fb4298b297217b184b9cd93c14f83536fcee829eb0ca850bdb5b53251f0',
         'com.android.tools.analytics-library:shared:26.3.2:shared-26.3.2.jar:ddd80dcf21905018b7c0583ba72b7282f446084d4952422609a09fbf8237ef71',
         'com.android.tools.analytics-library:tracker:26.3.2:tracker-26.3.2.jar:28c575d2d1af003e96d7b375a668ee10b2673a2dd0f6438750aa8c3b42e7d0ad',
-        'com.android.tools.build:aapt2:3.3.2-5309881:aapt2-3.3.2-5309881-linux.jar:9beead7e8b1057359049f450538aadcd3eb2a5bc3fbdd5e3296cb8fdc2a22412',
         'com.android.tools.build:apksig:3.3.2:apksig-3.3.2.jar:84c4aaa20127c6c1fe6bdd334b3f5df71f54ad080be9029c8a10f43b6a908acd',
         'com.android.tools.build:apkzlib:3.3.2:apkzlib-3.3.2.jar:d34e523278e5dff565eba3ef3c089d515b2b5cc7b47dc77e2f3465e5e47176ac',
         'com.android.tools.build:builder-model:3.3.2:builder-model-3.3.2.jar:055e3db0ecee9e06b9f024034999a29cd92cb1885207b37542126bd8bcc57f46',

bramble-api/src/main/java/org/briarproject/bramble/api/client/ContactGroupFactory.java

@@ -18,11 +18,10 @@ public interface ContactGroupFactory {
 	 * Creates a group for the given client to share with the given contact.
 	 */
 	Group createContactGroup(ClientId clientId, int majorVersion,
-			Contact contact);
+			Contact contact, AuthorId local);
 
 	/**
-	 * Creates a group for the given client to share between the given authors
-	 * identified by their AuthorIds.
+	 * Creates a group for the given client to share between the given authors.
 	 */
 	Group createContactGroup(ClientId clientId, int majorVersion,
 			AuthorId authorId1, AuthorId authorId2);

bramble-api/src/main/java/org/briarproject/bramble/api/contact/Contact.java

@@ -1,13 +1,13 @@
 package org.briarproject.bramble.api.contact;
 
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
+import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
 import static org.briarproject.bramble.util.StringUtils.toUtf8;
 
 @Immutable
@@ -16,24 +16,28 @@ public class Contact {
 
 	private final ContactId id;
 	private final Author author;
-	private final AuthorId localAuthorId;
 	@Nullable
 	private final String alias;
-	private final boolean verified, active;
+	@Nullable
+	private final byte[] handshakePublicKey;
+	private final boolean verified;
 
-	public Contact(ContactId id, Author author, AuthorId localAuthorId,
-			@Nullable String alias, boolean verified, boolean active) {
+	public Contact(ContactId id, Author author, @Nullable String alias,
+			@Nullable byte[] handshakePublicKey, boolean verified) {
 		if (alias != null) {
 			int aliasLength = toUtf8(alias).length;
 			if (aliasLength == 0 || aliasLength > MAX_AUTHOR_NAME_LENGTH)
 				throw new IllegalArgumentException();
 		}
+		if (handshakePublicKey != null && (handshakePublicKey.length == 0 ||
+				handshakePublicKey.length > MAX_PUBLIC_KEY_LENGTH)) {
+			throw new IllegalArgumentException();
+		}
 		this.id = id;
 		this.author = author;
-		this.localAuthorId = localAuthorId;
 		this.alias = alias;
+		this.handshakePublicKey = handshakePublicKey;
 		this.verified = verified;
-		this.active = active;
 	}
 
 	public ContactId getId() {
@@ -44,21 +48,18 @@ public class Contact {
 		return author;
 	}
 
-	public AuthorId getLocalAuthorId() {
-		return localAuthorId;
-	}
-
 	@Nullable
 	public String getAlias() {
 		return alias;
 	}
 
-	public boolean isVerified() {
-		return verified;
+	@Nullable
+	public byte[] getHandshakePublicKey() {
+		return handshakePublicKey;
 	}
 
-	public boolean isActive() {
-		return active;
+	public boolean isVerified() {
+		return verified;
 	}
 
 	@Override

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactExchangeTask.java

@@ -18,30 +18,30 @@ public interface ContactExchangeTask {
 	byte PROTOCOL_VERSION = 1;
 
 	/**
-	 * Label for deriving Alice's header key from the master secret.
+	 * Label for deriving Alice's header key from the master key.
 	 */
 	String ALICE_KEY_LABEL =
 			"org.briarproject.bramble.contact/ALICE_HEADER_KEY";
 
 	/**
-	 * Label for deriving Bob's header key from the master secret.
+	 * Label for deriving Bob's header key from the master key.
 	 */
 	String BOB_KEY_LABEL = "org.briarproject.bramble.contact/BOB_HEADER_KEY";
 
 	/**
-	 * Label for deriving Alice's key binding nonce from the master secret.
+	 * Label for deriving Alice's key binding nonce from the master key.
 	 */
 	String ALICE_NONCE_LABEL = "org.briarproject.bramble.contact/ALICE_NONCE";
 
 	/**
-	 * Label for deriving Bob's key binding nonce from the master secret.
+	 * Label for deriving Bob's key binding nonce from the master key.
 	 */
 	String BOB_NONCE_LABEL = "org.briarproject.bramble.contact/BOB_NONCE";
 
 	/**
 	 * Exchanges contact information with a remote peer.
 	 */
-	void startExchange(LocalAuthor localAuthor, SecretKey masterSecret,
+	void startExchange(LocalAuthor localAuthor, SecretKey masterKey,
 			DuplexTransportConnection conn, TransportId transportId,
 			boolean alice);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactManager.java

@@ -13,8 +13,6 @@ import java.util.Collection;
 
 import javax.annotation.Nullable;
 
-import static org.briarproject.bramble.api.contact.PendingContact.PendingContactState.FAILED;
-
 @NotNullByDefault
 public interface ContactManager {
 
@@ -26,34 +24,31 @@ public interface ContactManager {
 	void registerContactHook(ContactHook hook);
 
 	/**
-	 * Stores a contact associated with the given local and remote pseudonyms,
-	 * derives and stores transport keys for each transport, and returns an ID
-	 * for the contact.
+	 * Stores a contact with the given pseudonym, derives and stores transport
+	 * keys for each transport, and returns an ID for the contact.
 	 *
 	 * @param alice true if the local party is Alice
 	 */
-	ContactId addContact(Transaction txn, Author remote, AuthorId local,
-			SecretKey master, long timestamp, boolean alice, boolean verified,
-			boolean active) throws DbException;
-
-	/**
-	 * Stores a contact associated with the given local and remote pseudonyms
-	 * and returns an ID for the contact.
-	 */
-	ContactId addContact(Transaction txn, Author remote, AuthorId local,
-			boolean verified, boolean active) throws DbException;
-
-	/**
-	 * Stores a contact associated with the given local and remote pseudonyms,
-	 * derives and stores transport keys for each transport, and returns an ID
-	 * for the contact.
-	 *
-	 * @param alice true if the local party is Alice
-	 */
-	ContactId addContact(Author remote, AuthorId local, SecretKey master,
+	ContactId addContact(Transaction txn, Author a, SecretKey rootKey,
 			long timestamp, boolean alice, boolean verified, boolean active)
 			throws DbException;
 
+	/**
+	 * Stores a contact with the given pseudonym and returns an ID for the
+	 * contact.
+	 */
+	ContactId addContact(Transaction txn, Author a, boolean verified)
+			throws DbException;
+
+	/**
+	 * Stores a contact with the given pseudonym, derives and stores transport
+	 * keys for each transport, and returns an ID for the contact.
+	 *
+	 * @param alice true if the local party is Alice
+	 */
+	ContactId addContact(Author a, SecretKey rootKey, long timestamp,
+			boolean alice, boolean verified, boolean active) throws DbException;
+
 	/**
 	 * Returns the static link that needs to be sent to the contact to be added.
 	 */
@@ -79,7 +74,8 @@ public interface ContactManager {
 	Collection<PendingContact> getPendingContacts();
 
 	/**
-	 * Removes a {@link PendingContact} that is in state {@link FAILED}.
+	 * Removes a {@link PendingContact} that is in state
+	 * {@link PendingContactState FAILED}.
 	 */
 	void removePendingContact(PendingContact pendingContact);
 
@@ -89,27 +85,19 @@ public interface ContactManager {
 	Contact getContact(ContactId c) throws DbException;
 
 	/**
-	 * Returns the contact with the given remoteAuthorId
-	 * that was added by the LocalAuthor with the given localAuthorId
-	 *
-	 * @throws org.briarproject.bramble.api.db.NoSuchContactException
+	 * Returns the contact with the given ID.
 	 */
-	Contact getContact(AuthorId remoteAuthorId, AuthorId localAuthorId)
-			throws DbException;
+	Contact getContact(AuthorId a) throws DbException;
 
 	/**
-	 * Returns the contact with the given remoteAuthorId
-	 * that was added by the LocalAuthor with the given localAuthorId
-	 *
-	 * @throws org.briarproject.bramble.api.db.NoSuchContactException
+	 * Returns the contact with the given ID.
 	 */
-	Contact getContact(Transaction txn, AuthorId remoteAuthorId,
-			AuthorId localAuthorId) throws DbException;
+	Contact getContact(Transaction txn, AuthorId a) throws DbException;
 
 	/**
 	 * Returns all active contacts.
 	 */
-	Collection<Contact> getActiveContacts() throws DbException;
+	Collection<Contact> getContacts() throws DbException;
 
 	/**
 	 * Removes a contact and all associated state.
@@ -121,12 +109,6 @@ public interface ContactManager {
 	 */
 	void removeContact(Transaction txn, ContactId c) throws DbException;
 
-	/**
-	 * Marks a contact as active or inactive.
-	 */
-	void setContactActive(Transaction txn, ContactId c, boolean active)
-			throws DbException;
-
 	/**
 	 * Sets an alias name for the contact or unsets it if alias is null.
 	 */
@@ -140,16 +122,14 @@ public interface ContactManager {
 			throws DbException;
 
 	/**
-	 * Return true if a contact with this name and public key already exists
+	 * Returns true if a contact with this pseudonym already exists.
 	 */
-	boolean contactExists(Transaction txn, AuthorId remoteAuthorId,
-			AuthorId localAuthorId) throws DbException;
+	boolean contactExists(Transaction txn, AuthorId a) throws DbException;
 
 	/**
-	 * Return true if a contact with this name and public key already exists
+	 * Returns true if a contact with this pseudonym already exists.
 	 */
-	boolean contactExists(AuthorId remoteAuthorId, AuthorId localAuthorId)
-			throws DbException;
+	boolean contactExists(AuthorId a) throws DbException;
 
 	/**
 	 * Returns the {@link AuthorInfo} for the given author.

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContact.java

@@ -8,26 +8,29 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class PendingContact {
 
-	public enum PendingContactState {
-		WAITING_FOR_CONNECTION,
-		CONNECTED,
-		ADDING_CONTACT,
-		FAILED
-	}
-
 	private final PendingContactId id;
+	private final byte[] publicKey;
 	private final String alias;
 	private final PendingContactState state;
 	private final long timestamp;
 
-	public PendingContact(PendingContactId id, String alias,
-			PendingContactState state, long timestamp) {
+	public PendingContact(PendingContactId id, byte[] publicKey,
+			String alias, PendingContactState state, long timestamp) {
 		this.id = id;
+		this.publicKey = publicKey;
 		this.alias = alias;
 		this.state = state;
 		this.timestamp = timestamp;
 	}
 
+	public PendingContactId getId() {
+		return id;
+	}
+
+	public byte[] getPublicKey() {
+		return publicKey;
+	}
+
 	public String getAlias() {
 		return alias;
 	}
@@ -50,5 +53,4 @@ public class PendingContact {
 		return o instanceof PendingContact &&
 				id.equals(((PendingContact) o).id);
 	}
-
 }

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContactId.java

@@ -1,11 +1,25 @@
 package org.briarproject.bramble.api.contact;
 
 import org.briarproject.bramble.api.UniqueId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
+import javax.annotation.concurrent.ThreadSafe;
+
+/**
+ * Type-safe wrapper for a byte array that uniquely identifies a
+ * {@link PendingContact}.
+ */
+@ThreadSafe
+@NotNullByDefault
 public class PendingContactId extends UniqueId {
 
 	public PendingContactId(byte[] id) {
 		super(id);
 	}
 
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof PendingContactId && super.equals(o);
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContactState.java

@@ -0,0 +1,30 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public enum PendingContactState {
+
+	WAITING_FOR_CONNECTION(0),
+	CONNECTED(1),
+	ADDING_CONTACT(2),
+	FAILED(3);
+
+	private final int value;
+
+	PendingContactState(int value) {
+		this.value = value;
+	}
+
+	public int getValue() {
+		return value;
+	}
+
+	public static PendingContactState fromValue(int value) {
+		for (PendingContactState s : values()) if (s.value == value) return s;
+		throw new IllegalArgumentException();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/ContactAddedEvent.java

@@ -14,18 +14,12 @@ import javax.annotation.concurrent.Immutable;
 public class ContactAddedEvent extends Event {
 
 	private final ContactId contactId;
-	private final boolean active;
 
-	public ContactAddedEvent(ContactId contactId, boolean active) {
+	public ContactAddedEvent(ContactId contactId) {
 		this.contactId = contactId;
-		this.active = active;
 	}
 
 	public ContactId getContactId() {
 		return contactId;
 	}
-
-	public boolean isActive() {
-		return active;
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/ContactStatusChangedEvent.java

@@ -1,31 +0,0 @@
-package org.briarproject.bramble.api.contact.event;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when a contact is marked active or inactive.
- */
-@Immutable
-@NotNullByDefault
-public class ContactStatusChangedEvent extends Event {
-
-	private final ContactId contactId;
-	private final boolean active;
-
-	public ContactStatusChangedEvent(ContactId contactId, boolean active) {
-		this.contactId = contactId;
-		this.active = active;
-	}
-
-	public ContactId getContactId() {
-		return contactId;
-	}
-
-	public boolean isActive() {
-		return active;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/PendingContactStateChangedEvent.java

@@ -1,7 +1,7 @@
 package org.briarproject.bramble.api.contact.event;
 
-import org.briarproject.bramble.api.contact.PendingContact.PendingContactState;
 import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/KeyAgreementCrypto.java

@@ -2,7 +2,7 @@ package org.briarproject.bramble.api.crypto;
 
 /**
  * Crypto operations for the key agreement protocol - see
- * https://code.briarproject.org/akwizgran/briar-spec/blob/master/protocols/BQP.md
+ * https://code.briarproject.org/briar/briar-spec/blob/master/protocols/BQP.md
  */
 public interface KeyAgreementCrypto {
 

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/TransportCrypto.java

@@ -1,29 +1,45 @@
 package org.briarproject.bramble.api.crypto;
 
 import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 /**
  * Crypto operations for the transport security protocol - see
- * https://code.briarproject.org/akwizgran/briar-spec/blob/master/protocols/BTP.md
+ * https://code.briarproject.org/briar/briar-spec/blob/master/protocols/BTP.md
  */
 public interface TransportCrypto {
 
 	/**
 	 * Derives initial transport keys for the given transport in the given
-	 * rotation period from the given master secret.
+	 * time period from the given root key.
 	 *
 	 * @param alice whether the keys are for use by Alice or Bob.
 	 * @param active whether the keys are usable for outgoing streams.
 	 */
-	TransportKeys deriveTransportKeys(TransportId t, SecretKey master,
-			long rotationPeriod, boolean alice, boolean active);
+	TransportKeys deriveTransportKeys(TransportId t, SecretKey rootKey,
+			long timePeriod, boolean alice, boolean active);
 
 	/**
-	 * Rotates the given transport keys to the given rotation period. If the
-	 * keys are for the given period or any later period they are not rotated.
+	 * Rotates the given transport keys to the given time period. If the keys
+	 * are for the given period or any later period they are not rotated.
 	 */
-	TransportKeys rotateTransportKeys(TransportKeys k, long rotationPeriod);
+	TransportKeys rotateTransportKeys(TransportKeys k, long timePeriod);
+
+	/**
+	 * Derives handshake keys for the given transport in the given time period
+	 * from the given root key.
+	 *
+	 * @param alice whether the keys are for use by Alice or Bob.
+	 */
+	HandshakeKeys deriveHandshakeKeys(TransportId t, SecretKey rootKey,
+			long timePeriod, boolean alice);
+
+	/**
+	 * Updates the given handshake keys to the given time period. If the keys
+	 * are for the given period or any later period they are not updated.
+	 */
+	HandshakeKeys updateHandshakeKeys(HandshakeKeys k, long timePeriod);
 
 	/**
 	 * Encodes the pseudo-random tag that is used to recognise a stream.

bramble-api/src/main/java/org/briarproject/bramble/api/db/CommitAction.java

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.db;
+
+import org.briarproject.bramble.api.event.EventExecutor;
+
+/**
+ * An action that's taken when a {@link Transaction} is committed.
+ */
+public interface CommitAction {
+
+	void accept(Visitor visitor);
+
+	interface Visitor {
+
+		@EventExecutor
+		void visit(EventAction a);
+
+		@EventExecutor
+		void visit(TaskAction a);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseComponent.java

@@ -2,6 +2,8 @@ package org.briarproject.bramble.api.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
@@ -20,8 +22,11 @@ import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.Offer;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.validation.MessageState;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeySet;
+import org.briarproject.bramble.api.transport.HandshakeKeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.Collection;
@@ -97,17 +102,31 @@ public interface DatabaseComponent {
 			NullableDbCallable<R, E> task) throws DbException, E;
 
 	/**
-	 * Stores a contact associated with the given local and remote pseudonyms,
-	 * and returns an ID for the contact.
+	 * Stores a contact with the given pseudonym and returns an ID for the
+	 * contact.
 	 */
-	ContactId addContact(Transaction txn, Author remote, AuthorId local,
-			boolean verified, boolean active) throws DbException;
+	ContactId addContact(Transaction txn, Author a, boolean verified)
+			throws DbException;
 
 	/**
 	 * Stores a group.
 	 */
 	void addGroup(Transaction txn, Group g) throws DbException;
 
+	/**
+	 * Stores the given handshake keys for the given contact and returns a
+	 * key set ID.
+	 */
+	HandshakeKeySetId addHandshakeKeys(Transaction txn, ContactId c,
+			HandshakeKeys k) throws DbException;
+
+	/**
+	 * Stores the given handshake keys for the given pending contact and
+	 * returns a key set ID.
+	 */
+	HandshakeKeySetId addHandshakeKeys(Transaction txn, PendingContactId p,
+			HandshakeKeys k) throws DbException;
+
 	/**
 	 * Stores a local pseudonym.
 	 */
@@ -119,6 +138,12 @@ public interface DatabaseComponent {
 	void addLocalMessage(Transaction txn, Message m, Metadata meta,
 			boolean shared) throws DbException;
 
+	/**
+	 * Stores a pending contact.
+	 */
+	void addPendingContact(Transaction txn, PendingContact p)
+			throws DbException;
+
 	/**
 	 * Stores a transport.
 	 */
@@ -129,27 +154,39 @@ public interface DatabaseComponent {
 	 * Stores the given transport keys for the given contact and returns a
 	 * key set ID.
 	 */
-	KeySetId addTransportKeys(Transaction txn, ContactId c,
+	TransportKeySetId addTransportKeys(Transaction txn, ContactId c,
 			TransportKeys k) throws DbException;
 
 	/**
-	 * Returns true if the database contains the given contact for the given
-	 * local pseudonym.
+	 * Returns true if the database contains the given contact.
+	 * <p/>
+	 * Read-only.
 	 */
-	boolean containsContact(Transaction txn, AuthorId remote, AuthorId local)
-			throws DbException;
+	boolean containsContact(Transaction txn, AuthorId a) throws DbException;
 
 	/**
 	 * Returns true if the database contains the given group.
+	 * <p/>
+	 * Read-only.
 	 */
 	boolean containsGroup(Transaction txn, GroupId g) throws DbException;
 
 	/**
 	 * Returns true if the database contains the given local author.
+	 * <p/>
+	 * Read-only.
 	 */
 	boolean containsLocalAuthor(Transaction txn, AuthorId local)
 			throws DbException;
 
+	/**
+	 * Returns true if the database contains the given pending contact.
+	 * <p/>
+	 * Read-only.
+	 */
+	boolean containsPendingContact(Transaction txn, PendingContactId p)
+			throws DbException;
+
 	/**
 	 * Deletes the message with the given ID. Unlike
 	 * {@link #removeMessage(Transaction, MessageId)}, the message ID,
@@ -215,6 +252,13 @@ public interface DatabaseComponent {
 	 */
 	Contact getContact(Transaction txn, ContactId c) throws DbException;
 
+	/**
+	 * Returns the contact with the given author ID.
+	 * <p/>
+	 * Read-only.
+	 */
+	Contact getContact(Transaction txn, AuthorId a) throws DbException;
+
 	/**
 	 * Returns all contacts.
 	 * <p/>
@@ -222,22 +266,6 @@ public interface DatabaseComponent {
 	 */
 	Collection<Contact> getContacts(Transaction txn) throws DbException;
 
-	/**
-	 * Returns a possibly empty collection of contacts with the given author ID.
-	 * <p/>
-	 * Read-only.
-	 */
-	Collection<Contact> getContactsByAuthorId(Transaction txn, AuthorId remote)
-			throws DbException;
-
-	/**
-	 * Returns all contacts associated with the given local pseudonym.
-	 * <p/>
-	 * Read-only.
-	 */
-	Collection<ContactId> getContacts(Transaction txn, AuthorId a)
-			throws DbException;
-
 	/**
 	 * Returns the group with the given ID.
 	 * <p/>
@@ -269,6 +297,14 @@ public interface DatabaseComponent {
 	Visibility getGroupVisibility(Transaction txn, ContactId c, GroupId g)
 			throws DbException;
 
+	/**
+	 * Returns all handshake keys for the given transport.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<HandshakeKeySet> getHandshakeKeys(Transaction txn, TransportId t)
+			throws DbException;
+
 	/**
 	 * Returns the local pseudonym with the given ID.
 	 * <p/>
@@ -417,6 +453,14 @@ public interface DatabaseComponent {
 	 */
 	long getNextSendTime(Transaction txn, ContactId c) throws DbException;
 
+	/**
+	 * Returns all pending contacts.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<PendingContact> getPendingContacts(Transaction txn)
+			throws DbException;
+
 	/**
 	 * Returns all settings in the given namespace.
 	 * <p/>
@@ -429,14 +473,20 @@ public interface DatabaseComponent {
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<KeySet> getTransportKeys(Transaction txn, TransportId t)
+	Collection<TransportKeySet> getTransportKeys(Transaction txn, TransportId t)
 			throws DbException;
 
+	/**
+	 * Increments the outgoing stream counter for the given handshake keys.
+	 */
+	void incrementStreamCounter(Transaction txn, TransportId t,
+			HandshakeKeySetId k) throws DbException;
+
 	/**
 	 * Increments the outgoing stream counter for the given transport keys.
 	 */
-	void incrementStreamCounter(Transaction txn, TransportId t, KeySetId k)
-			throws DbException;
+	void incrementStreamCounter(Transaction txn, TransportId t,
+			TransportKeySetId k) throws DbException;
 
 	/**
 	 * Merges the given metadata with the existing metadata for the given
@@ -491,6 +541,12 @@ public interface DatabaseComponent {
 	 */
 	void removeGroup(Transaction txn, Group g) throws DbException;
 
+	/**
+	 * Removes the given handshake keys from the database.
+	 */
+	void removeHandshakeKeys(Transaction txn, TransportId t,
+			HandshakeKeySetId k) throws DbException;
+
 	/**
 	 * Removes a local pseudonym (and all associated state) from the database.
 	 */
@@ -501,6 +557,12 @@ public interface DatabaseComponent {
 	 */
 	void removeMessage(Transaction txn, MessageId m) throws DbException;
 
+	/**
+	 * Removes a pending contact (and all associated state) from the database.
+	 */
+	void removePendingContact(Transaction txn, PendingContactId p)
+			throws DbException;
+
 	/**
 	 * Removes a transport (and all associated state) from the database.
 	 */
@@ -509,20 +571,14 @@ public interface DatabaseComponent {
 	/**
 	 * Removes the given transport keys from the database.
 	 */
-	void removeTransportKeys(Transaction txn, TransportId t, KeySetId k)
-			throws DbException;
+	void removeTransportKeys(Transaction txn, TransportId t,
+			TransportKeySetId k) throws DbException;
 
 	/**
 	 * Marks the given contact as verified.
 	 */
 	void setContactVerified(Transaction txn, ContactId c) throws DbException;
 
-	/**
-	 * Marks the given contact as active or inactive.
-	 */
-	void setContactActive(Transaction txn, ContactId c, boolean active)
-			throws DbException;
-
 	/**
 	 * Sets an alias name for the contact or unsets it if alias is null.
 	 */
@@ -553,21 +609,36 @@ public interface DatabaseComponent {
 			Collection<MessageId> dependencies) throws DbException;
 
 	/**
-	 * Sets the reordering window for the given key set and transport in the
-	 * given rotation period.
+	 * Sets the reordering window for the given transport key set in the given
+	 * time period.
 	 */
-	void setReorderingWindow(Transaction txn, KeySetId k, TransportId t,
-			long rotationPeriod, long base, byte[] bitmap) throws DbException;
+	void setReorderingWindow(Transaction txn, TransportKeySetId k,
+			TransportId t, long timePeriod, long base, byte[] bitmap)
+			throws DbException;
+
+	/**
+	 * Sets the reordering window for the given handshake key set in the given
+	 * time period.
+	 */
+	void setReorderingWindow(Transaction txn, HandshakeKeySetId k,
+			TransportId t, long timePeriod, long base, byte[] bitmap)
+			throws DbException;
 
 	/**
 	 * Marks the given transport keys as usable for outgoing streams.
 	 */
-	void setTransportKeysActive(Transaction txn, TransportId t, KeySetId k)
+	void setTransportKeysActive(Transaction txn, TransportId t,
+			TransportKeySetId k) throws DbException;
+
+	/**
+	 * Stores the given handshake keys, deleting any keys they have replaced.
+	 */
+	void updateHandshakeKeys(Transaction txn, Collection<HandshakeKeySet> keys)
 			throws DbException;
 
 	/**
 	 * Stores the given transport keys, deleting any keys they have replaced.
 	 */
-	void updateTransportKeys(Transaction txn, Collection<KeySet> keys)
+	void updateTransportKeys(Transaction txn, Collection<TransportKeySet> keys)
 			throws DbException;
 }

bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseConfig.java

@@ -10,6 +10,4 @@ public interface DatabaseConfig {
 	File getDatabaseDirectory();
 
 	File getDatabaseKeyDirectory();
-
-	long getMaxSize();
 }

bramble-api/src/main/java/org/briarproject/bramble/api/db/EventAction.java

@@ -0,0 +1,24 @@
+package org.briarproject.bramble.api.db;
+
+import org.briarproject.bramble.api.event.Event;
+
+/**
+ * A {@link CommitAction} that broadcasts an event.
+ */
+public class EventAction implements CommitAction {
+
+	private final Event event;
+
+	EventAction(Event event) {
+		this.event = event;
+	}
+
+	public Event getEvent() {
+		return event;
+	}
+
+	@Override
+	public void accept(Visitor visitor) {
+		visitor.visit(this);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/db/NoSuchPendingContactException.java

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api.db;
+
+/**
+ * Thrown when a database operation is attempted for a pending contact that is
+ * not in the database. This exception may occur due to concurrent updates and
+ * does not indicate a database error.
+ */
+public class NoSuchPendingContactException extends DbException {
+}

bramble-api/src/main/java/org/briarproject/bramble/api/db/PendingContactExistsException.java

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api.db;
+
+/**
+ * Thrown when a duplicate pending contact is added to the database. This
+ * exception may occur due to concurrent updates and does not indicate a
+ * database error.
+ */
+public class PendingContactExistsException extends DbException {
+}

bramble-api/src/main/java/org/briarproject/bramble/api/db/TaskAction.java

@@ -0,0 +1,24 @@
+package org.briarproject.bramble.api.db;
+
+import org.briarproject.bramble.api.event.EventExecutor;
+
+/**
+ * A {@link CommitAction} that submits a task to the {@link EventExecutor}.
+ */
+public class TaskAction implements CommitAction {
+
+	private final Runnable task;
+
+	TaskAction(Runnable task) {
+		this.task = task;
+	}
+
+	public Runnable getTask() {
+		return task;
+	}
+
+	@Override
+	public void accept(Visitor visitor) {
+		visitor.visit(this);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/db/Transaction.java

@@ -1,13 +1,15 @@
 package org.briarproject.bramble.api.db;
 
 import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventExecutor;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
+import static java.util.Collections.emptyList;
+
 /**
  * A wrapper around a database transaction. Transactions are not thread-safe.
  */
@@ -17,7 +19,7 @@ public class Transaction {
 	private final Object txn;
 	private final boolean readOnly;
 
-	private List<Event> events = null;
+	private List<CommitAction> actions = null;
 	private boolean committed = false;
 
 	public Transaction(Object txn, boolean readOnly) {
@@ -42,19 +44,27 @@ public class Transaction {
 
 	/**
 	 * Attaches an event to be broadcast when the transaction has been
-	 * committed.
+	 * committed. The event will be broadcast on the {@link EventExecutor}.
 	 */
 	public void attach(Event e) {
-		if (events == null) events = new ArrayList<>();
-		events.add(e);
+		if (actions == null) actions = new ArrayList<>();
+		actions.add(new EventAction(e));
 	}
 
 	/**
-	 * Returns any events attached to the transaction.
+	 * Attaches a task to be executed when the transaction has been
+	 * committed. The task will be run on the {@link EventExecutor}.
 	 */
-	public List<Event> getEvents() {
-		if (events == null) return Collections.emptyList();
-		return events;
+	public void attach(Runnable r) {
+		if (actions == null) actions = new ArrayList<>();
+		actions.add(new TaskAction(r));
+	}
+
+	/**
+	 * Returns any actions attached to the transaction.
+	 */
+	public List<CommitAction> getActions() {
+		return actions == null ? emptyList() : actions;
 	}
 
 	/**

bramble-api/src/main/java/org/briarproject/bramble/api/event/EventBus.java

@@ -16,7 +16,8 @@ public interface EventBus {
 	void removeListener(EventListener l);
 
 	/**
-	 * Notifies all listeners of an event.
+	 * Asynchronously notifies all listeners of an event. Listeners are
+	 * notified on the {@link EventExecutor}.
 	 */
 	void broadcast(Event e);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/event/EventExecutor.java

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api.event;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import javax.inject.Qualifier;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * Annotation for injecting the executor for broadcasting events and running
+ * tasks that need to run in a defined order with respect to events. Also used
+ * for annotating methods that should run on the event executor.
+ * <p>
+ * The contract of this executor is that tasks are run in the order they're
+ * submitted, tasks are not run concurrently, and submitting a task will never
+ * block. Tasks must not block. Tasks submitted during shutdown are discarded.
+ */
+@Qualifier
+@Target({FIELD, METHOD, PARAMETER})
+@Retention(RUNTIME)
+public @interface EventExecutor {
+}

bramble-api/src/main/java/org/briarproject/bramble/api/event/EventListener.java

@@ -12,5 +12,6 @@ public interface EventListener {
 	 * Called when an event is broadcast. Implementations of this method must
 	 * not block.
 	 */
+	@EventExecutor
 	void eventOccurred(Event e);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/identity/LocalAuthor.java

@@ -2,8 +2,11 @@ package org.briarproject.bramble.api.identity;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
+import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
+
 /**
  * A pseudonym for the local user.
  */
@@ -12,6 +15,8 @@ import javax.annotation.concurrent.Immutable;
 public class LocalAuthor extends Author {
 
 	private final byte[] privateKey;
+	@Nullable
+	private final byte[] handshakePublicKey, handshakePrivateKey;
 	private final long created;
 
 	public LocalAuthor(AuthorId id, int formatVersion, String name,
@@ -19,6 +24,22 @@ public class LocalAuthor extends Author {
 		super(id, formatVersion, name, publicKey);
 		this.privateKey = privateKey;
 		this.created = created;
+		handshakePublicKey = null;
+		handshakePrivateKey = null;
+	}
+
+	public LocalAuthor(AuthorId id, int formatVersion, String name,
+			byte[] publicKey, byte[] privateKey, byte[] handshakePublicKey,
+			byte[] handshakePrivateKey, long created) {
+		super(id, formatVersion, name, publicKey);
+		if (handshakePublicKey.length == 0 ||
+				handshakePublicKey.length > MAX_PUBLIC_KEY_LENGTH) {
+			throw new IllegalArgumentException();
+		}
+		this.privateKey = privateKey;
+		this.handshakePublicKey = handshakePublicKey;
+		this.handshakePrivateKey = handshakePrivateKey;
+		this.created = created;
 	}
 
 	/**
@@ -28,6 +49,22 @@ public class LocalAuthor extends Author {
 		return privateKey;
 	}
 
+	/**
+	 * Returns the public key used for handshaking, or null if no key exists.
+	 */
+	@Nullable
+	public byte[] getHandshakePublicKey() {
+		return handshakePublicKey;
+	}
+
+	/**
+	 * Returns the private key used for handshaking, or null if no key exists.
+	 */
+	@Nullable
+	public byte[] getHandshakePrivateKey() {
+		return handshakePrivateKey;
+	}
+
 	/**
 	 * Returns the time the pseudonym was created, in milliseconds since the
 	 * Unix epoch.

bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementConstants.java

@@ -40,8 +40,8 @@ public interface KeyAgreementConstants {
 			"org.briarproject.bramble.keyagreement/SHARED_SECRET";
 
 	/**
-	 * Label for deriving the master secret.
+	 * Label for deriving the master key.
 	 */
-	String MASTER_SECRET_LABEL =
+	String MASTER_KEY_LABEL =
 			"org.briarproject.bramble.keyagreement/MASTER_SECRET";
 }

bramble-api/src/main/java/org/briarproject/bramble/api/transport/AbstractTransportKeys.java

@@ -0,0 +1,57 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * Abstract superclass for {@link TransportKeys} and {@link HandshakeKeys}.
+ */
+@Immutable
+@NotNullByDefault
+public abstract class AbstractTransportKeys {
+
+	private final TransportId transportId;
+	private final IncomingKeys inPrev, inCurr, inNext;
+	private final OutgoingKeys outCurr;
+
+	AbstractTransportKeys(TransportId transportId, IncomingKeys inPrev,
+			IncomingKeys inCurr, IncomingKeys inNext, OutgoingKeys outCurr) {
+		if (inPrev.getTimePeriod() != outCurr.getTimePeriod() - 1)
+			throw new IllegalArgumentException();
+		if (inCurr.getTimePeriod() != outCurr.getTimePeriod())
+			throw new IllegalArgumentException();
+		if (inNext.getTimePeriod() != outCurr.getTimePeriod() + 1)
+			throw new IllegalArgumentException();
+		this.transportId = transportId;
+		this.inPrev = inPrev;
+		this.inCurr = inCurr;
+		this.inNext = inNext;
+		this.outCurr = outCurr;
+	}
+
+	public TransportId getTransportId() {
+		return transportId;
+	}
+
+	public IncomingKeys getPreviousIncomingKeys() {
+		return inPrev;
+	}
+
+	public IncomingKeys getCurrentIncomingKeys() {
+		return inCurr;
+	}
+
+	public IncomingKeys getNextIncomingKeys() {
+		return inNext;
+	}
+
+	public OutgoingKeys getCurrentOutgoingKeys() {
+		return outCurr;
+	}
+
+	public long getTimePeriod() {
+		return outCurr.getTimePeriod();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/HandshakeKeySet.java

@@ -0,0 +1,70 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * A set of keys for handshaking with a given contact or pending contact over a
+ * given transport. Unlike a {@link TransportKeySet} these keys do not provide
+ * forward secrecy.
+ */
+@Immutable
+@NotNullByDefault
+public class HandshakeKeySet {
+
+	private final HandshakeKeySetId keySetId;
+	@Nullable
+	private final ContactId contactId;
+	@Nullable
+	private final PendingContactId pendingContactId;
+	private final HandshakeKeys keys;
+
+	public HandshakeKeySet(HandshakeKeySetId keySetId, ContactId contactId,
+			HandshakeKeys keys) {
+		this.keySetId = keySetId;
+		this.contactId = contactId;
+		this.keys = keys;
+		pendingContactId = null;
+	}
+
+	public HandshakeKeySet(HandshakeKeySetId keySetId,
+			PendingContactId pendingContactId, HandshakeKeys keys) {
+		this.keySetId = keySetId;
+		this.pendingContactId = pendingContactId;
+		this.keys = keys;
+		contactId = null;
+	}
+
+	public HandshakeKeySetId getKeySetId() {
+		return keySetId;
+	}
+
+	@Nullable
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	@Nullable
+	public PendingContactId getPendingContactId() {
+		return pendingContactId;
+	}
+
+	public HandshakeKeys getKeys() {
+		return keys;
+	}
+
+	@Override
+	public int hashCode() {
+		return keySetId.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof HandshakeKeySet &&
+				keySetId.equals(((HandshakeKeySet) o).keySetId);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/HandshakeKeySetId.java

@@ -0,0 +1,36 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * Type-safe wrapper for an integer that uniquely identifies a
+ * {@link HandshakeKeySet set of handshake keys} within the scope of the local
+ * device.
+ */
+@Immutable
+@NotNullByDefault
+public class HandshakeKeySetId {
+
+	private final int id;
+
+	public HandshakeKeySetId(int id) {
+		this.id = id;
+	}
+
+	public int getInt() {
+		return id;
+	}
+
+	@Override
+	public int hashCode() {
+		return id;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof HandshakeKeySetId &&
+				id == ((HandshakeKeySetId) o).id;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/HandshakeKeys.java

@@ -0,0 +1,36 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * Keys for handshaking with a given contact or pending contact over a given
+ * transport. Unlike {@link TransportKeys} these keys do not provide forward
+ * secrecy.
+ */
+@Immutable
+@NotNullByDefault
+public class HandshakeKeys extends AbstractTransportKeys {
+
+	private final SecretKey rootKey;
+	private final boolean alice;
+
+	public HandshakeKeys(TransportId transportId, IncomingKeys inPrev,
+			IncomingKeys inCurr, IncomingKeys inNext, OutgoingKeys outCurr,
+			SecretKey rootKey, boolean alice) {
+		super(transportId, inPrev, inCurr, inNext, outCurr);
+		this.rootKey = rootKey;
+		this.alice = alice;
+	}
+
+	public SecretKey getRootKey() {
+		return rootKey;
+	}
+
+	public boolean isAlice() {
+		return alice;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/IncomingKeys.java

@@ -1,30 +1,35 @@
 package org.briarproject.bramble.api.transport;
 
 import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
 
 import static org.briarproject.bramble.api.transport.TransportConstants.REORDERING_WINDOW_SIZE;
 
 /**
  * Contains transport keys for receiving streams from a given contact over a
- * given transport in a given rotation period.
+ * given transport in a given time period.
  */
+@Immutable
+@NotNullByDefault
 public class IncomingKeys {
 
 	private final SecretKey tagKey, headerKey;
-	private final long rotationPeriod, windowBase;
+	private final long timePeriod, windowBase;
 	private final byte[] windowBitmap;
 
 	public IncomingKeys(SecretKey tagKey, SecretKey headerKey,
-			long rotationPeriod) {
-		this(tagKey, headerKey, rotationPeriod, 0,
+			long timePeriod) {
+		this(tagKey, headerKey, timePeriod, 0,
 				new byte[REORDERING_WINDOW_SIZE / 8]);
 	}
 
 	public IncomingKeys(SecretKey tagKey, SecretKey headerKey,
-			long rotationPeriod, long windowBase, byte[] windowBitmap) {
+			long timePeriod, long windowBase, byte[] windowBitmap) {
 		this.tagKey = tagKey;
 		this.headerKey = headerKey;
-		this.rotationPeriod = rotationPeriod;
+		this.timePeriod = timePeriod;
 		this.windowBase = windowBase;
 		this.windowBitmap = windowBitmap;
 	}
@@ -37,8 +42,8 @@ public class IncomingKeys {
 		return headerKey;
 	}
 
-	public long getRotationPeriod() {
-		return rotationPeriod;
+	public long getTimePeriod() {
+		return timePeriod;
 	}
 
 	public long getWindowBase() {

bramble-api/src/main/java/org/briarproject/bramble/api/transport/KeyManager.java

@@ -27,14 +27,14 @@ public interface KeyManager {
 	 * @param alice true if the local party is Alice
 	 * @param active whether the derived keys can be used for outgoing streams
 	 */
-	Map<TransportId, KeySetId> addContact(Transaction txn, ContactId c,
-			SecretKey master, long timestamp, boolean alice, boolean active)
+	Map<TransportId, TransportKeySetId> addContact(Transaction txn, ContactId c,
+			SecretKey rootKey, long timestamp, boolean alice, boolean active)
 			throws DbException;
 
 	/**
 	 * Marks the given transport keys as usable for outgoing streams.
 	 */
-	void activateKeys(Transaction txn, Map<TransportId, KeySetId> keys)
+	void activateKeys(Transaction txn, Map<TransportId, TransportKeySetId> keys)
 			throws DbException;
 
 	/**

bramble-api/src/main/java/org/briarproject/bramble/api/transport/KeySet.java

@@ -1,47 +0,0 @@
-package org.briarproject.bramble.api.transport;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * A set of transport keys for communicating with a contact.
- */
-@Immutable
-@NotNullByDefault
-public class KeySet {
-
-	private final KeySetId keySetId;
-	private final ContactId contactId;
-	private final TransportKeys transportKeys;
-
-	public KeySet(KeySetId keySetId, ContactId contactId,
-			TransportKeys transportKeys) {
-		this.keySetId = keySetId;
-		this.contactId = contactId;
-		this.transportKeys = transportKeys;
-	}
-
-	public KeySetId getKeySetId() {
-		return keySetId;
-	}
-
-	public ContactId getContactId() {
-		return contactId;
-	}
-
-	public TransportKeys getTransportKeys() {
-		return transportKeys;
-	}
-
-	@Override
-	public int hashCode() {
-		return keySetId.hashCode();
-	}
-
-	@Override
-	public boolean equals(Object o) {
-		return o instanceof KeySet && keySetId.equals(((KeySet) o).keySetId);
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/OutgoingKeys.java

@@ -1,27 +1,32 @@
 package org.briarproject.bramble.api.transport;
 
 import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
 
 /**
  * Contains transport keys for sending streams to a given contact over a given
- * transport in a given rotation period.
+ * transport in a given time period.
  */
+@Immutable
+@NotNullByDefault
 public class OutgoingKeys {
 
 	private final SecretKey tagKey, headerKey;
-	private final long rotationPeriod, streamCounter;
+	private final long timePeriod, streamCounter;
 	private final boolean active;
 
 	public OutgoingKeys(SecretKey tagKey, SecretKey headerKey,
-			long rotationPeriod, boolean active) {
-		this(tagKey, headerKey, rotationPeriod, 0, active);
+			long timePeriod, boolean active) {
+		this(tagKey, headerKey, timePeriod, 0, active);
 	}
 
 	public OutgoingKeys(SecretKey tagKey, SecretKey headerKey,
-			long rotationPeriod, long streamCounter, boolean active) {
+			long timePeriod, long streamCounter, boolean active) {
 		this.tagKey = tagKey;
 		this.headerKey = headerKey;
-		this.rotationPeriod = rotationPeriod;
+		this.timePeriod = timePeriod;
 		this.streamCounter = streamCounter;
 		this.active = active;
 	}
@@ -34,8 +39,8 @@ public class OutgoingKeys {
 		return headerKey;
 	}
 
-	public long getRotationPeriod() {
-		return rotationPeriod;
+	public long getTimePeriod() {
+		return timePeriod;
 	}
 
 	public long getStreamCounter() {

bramble-api/src/main/java/org/briarproject/bramble/api/transport/StreamContext.java

@@ -2,8 +2,13 @@ package org.briarproject.bramble.api.transport;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
 public class StreamContext {
 
 	private final ContactId contactId;

bramble-api/src/main/java/org/briarproject/bramble/api/transport/TransportConstants.java

@@ -82,30 +82,58 @@ public interface TransportConstants {
 	int REORDERING_WINDOW_SIZE = 32;
 
 	/**
-	 * Label for deriving Alice's initial tag key from the master secret.
+	 * Label for deriving Alice's initial tag key from the root key in
+	 * rotation mode.
 	 */
 	String ALICE_TAG_LABEL = "org.briarproject.bramble.transport/ALICE_TAG_KEY";
 
 	/**
-	 * Label for deriving Bob's initial tag key from the master secret.
+	 * Label for deriving Bob's initial tag key from the root key in rotation
+	 * mode.
 	 */
 	String BOB_TAG_LABEL = "org.briarproject.bramble.transport/BOB_TAG_KEY";
 
 	/**
-	 * Label for deriving Alice's initial header key from the master secret.
+	 * Label for deriving Alice's initial header key from the root key in
+	 * rotation mode.
 	 */
 	String ALICE_HEADER_LABEL =
 			"org.briarproject.bramble.transport/ALICE_HEADER_KEY";
 
 	/**
-	 * Label for deriving Bob's initial header key from the master secret.
+	 * Label for deriving Bob's initial header key from the root key in
+	 * rotation mode.
 	 */
 	String BOB_HEADER_LABEL =
 			"org.briarproject.bramble.transport/BOB_HEADER_KEY";
 
 	/**
-	 * Label for deriving the next period's key in key rotation.
+	 * Label for deriving the next period's key in rotation mode.
 	 */
 	String ROTATE_LABEL = "org.briarproject.bramble.transport/ROTATE";
 
+	/**
+	 * Label for deriving Alice's tag key from the root key in handshake mode.
+	 */
+	String ALICE_HANDSHAKE_TAG_LABEL =
+			"org.briarproject.bramble.transport/ALICE_HANDSHAKE_TAG_KEY";
+
+	/**
+	 * Label for deriving Bob's tag key from the root key in handshake mode.
+	 */
+	String BOB_HANDSHAKE_TAG_LABEL =
+			"org.briarproject.bramble.transport/BOB_HANDSHAKE_TAG_KEY";
+
+	/**
+	 * Label for deriving Alice's header key from the root key in handshake
+	 * mode.
+	 */
+	String ALICE_HANDSHAKE_HEADER_LABEL =
+			"org.briarproject.bramble.transport/ALICE_HANDSHAKE_HEADER_KEY";
+
+	/**
+	 * Label for deriving Bob's header key from the root key in handshake mode.
+	 */
+	String BOB_HANDSHAKE_HEADER_LABEL =
+			"org.briarproject.bramble.transport/BOB_HANDSHAKE_HEADER_KEY";
 }

bramble-api/src/main/java/org/briarproject/bramble/api/transport/TransportKeySet.java

@@ -0,0 +1,49 @@
+package org.briarproject.bramble.api.transport;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * A set of keys for communicating with a given contact over a given transport.
+ * Unlike a {@link HandshakeKeySet} these keys provide forward secrecy.
+ */
+@Immutable
+@NotNullByDefault
+public class TransportKeySet {
+
+	private final TransportKeySetId keySetId;
+	private final ContactId contactId;
+	private final TransportKeys keys;
+
+	public TransportKeySet(TransportKeySetId keySetId, ContactId contactId,
+			TransportKeys keys) {
+		this.keySetId = keySetId;
+		this.contactId = contactId;
+		this.keys = keys;
+	}
+
+	public TransportKeySetId getKeySetId() {
+		return keySetId;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	public TransportKeys getKeys() {
+		return keys;
+	}
+
+	@Override
+	public int hashCode() {
+		return keySetId.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof TransportKeySet &&
+				keySetId.equals(((TransportKeySet) o).keySetId);
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/TransportKeySetId.java

@@ -5,18 +5,19 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import javax.annotation.concurrent.Immutable;
 
 /**
- * Type-safe wrapper for an integer that uniquely identifies a set of transport
- * keys within the scope of the local device.
+ * Type-safe wrapper for an integer that uniquely identifies a
+ * {@link TransportKeySet set of transport keys} within the scope of the local
+ * device.
  * <p/>
  * Key sets created on a given device must have increasing identifiers.
  */
 @Immutable
 @NotNullByDefault
-public class KeySetId {
+public class TransportKeySetId {
 
 	private final int id;
 
-	public KeySetId(int id) {
+	public TransportKeySetId(int id) {
 		this.id = id;
 	}
 
@@ -31,6 +32,7 @@ public class KeySetId {
 
 	@Override
 	public boolean equals(Object o) {
-		return o instanceof KeySetId && id == ((KeySetId) o).id;
+		return o instanceof TransportKeySetId &&
+				id == ((TransportKeySetId) o).id;
 	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/transport/TransportKeys.java

@@ -1,52 +1,20 @@
 package org.briarproject.bramble.api.transport;
 
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 
-/**
- * Keys for communicating with a given contact over a given transport.
- */
-public class TransportKeys {
+import javax.annotation.concurrent.Immutable;
 
-	private final TransportId transportId;
-	private final IncomingKeys inPrev, inCurr, inNext;
-	private final OutgoingKeys outCurr;
+/**
+ * Keys for communicating with a given contact over a given transport. Unlike
+ * {@link HandshakeKeys} these keys provide forward secrecy.
+ */
+@Immutable
+@NotNullByDefault
+public class TransportKeys extends AbstractTransportKeys {
 
 	public TransportKeys(TransportId transportId, IncomingKeys inPrev,
 			IncomingKeys inCurr, IncomingKeys inNext, OutgoingKeys outCurr) {
-		if (inPrev.getRotationPeriod() != inCurr.getRotationPeriod() - 1)
-			throw new IllegalArgumentException();
-		if (inNext.getRotationPeriod() != inCurr.getRotationPeriod() + 1)
-			throw new IllegalArgumentException();
-		if (outCurr.getRotationPeriod() != inCurr.getRotationPeriod())
-			throw new IllegalArgumentException();
-		this.transportId = transportId;
-		this.inPrev = inPrev;
-		this.inCurr = inCurr;
-		this.inNext = inNext;
-		this.outCurr = outCurr;
-	}
-
-	public TransportId getTransportId() {
-		return transportId;
-	}
-
-	public IncomingKeys getPreviousIncomingKeys() {
-		return inPrev;
-	}
-
-	public IncomingKeys getCurrentIncomingKeys() {
-		return inCurr;
-	}
-
-	public IncomingKeys getNextIncomingKeys() {
-		return inNext;
-	}
-
-	public OutgoingKeys getCurrentOutgoingKeys() {
-		return outCurr;
-	}
-
-	public long getRotationPeriod() {
-		return outCurr.getRotationPeriod();
+		super(transportId, inPrev, inCurr, inNext, outCurr);
 	}
 }

bramble-api/src/test/java/org/briarproject/bramble/test/TestUtils.java

@@ -1,6 +1,10 @@
 package org.briarproject.bramble.test;
 
 import org.briarproject.bramble.api.UniqueId;
+import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
@@ -25,6 +29,7 @@ import java.util.Random;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import static java.util.Arrays.asList;
+import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.api.identity.Author.FORMAT_VERSION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
@@ -41,6 +46,7 @@ public class TestUtils {
 			new AtomicInteger((int) (Math.random() * 1000 * 1000));
 	private static final Random random = new Random();
 	private static final long timestamp = System.currentTimeMillis();
+	private static final AtomicInteger nextContactId = new AtomicInteger(1);
 
 	public static File getTestDirectory() {
 		int name = nextTestDir.getAndIncrement();
@@ -140,6 +146,35 @@ public class TestUtils {
 		return new Message(id, groupId, timestamp, body);
 	}
 
+	public static PendingContact getPendingContact() {
+		return getPendingContact(1 + random.nextInt(MAX_AUTHOR_NAME_LENGTH));
+	}
+
+	public static PendingContact getPendingContact(int nameLength) {
+		PendingContactId id = new PendingContactId(getRandomId());
+		byte[] publicKey = getRandomBytes(MAX_PUBLIC_KEY_LENGTH);
+		String alias = getRandomString(nameLength);
+		return new PendingContact(id, publicKey, alias, WAITING_FOR_CONNECTION,
+				timestamp);
+	}
+
+	public static ContactId getContactId() {
+		return new ContactId(nextContactId.getAndIncrement());
+	}
+
+	public static Contact getContact() {
+		return getContact(getAuthor(), random.nextBoolean());
+	}
+
+	public static Contact getContact(Author a, boolean verified) {
+		return getContact(getContactId(), a, verified);
+	}
+
+	public static Contact getContact(ContactId c, Author a, boolean verified) {
+		return new Contact(c, a, getRandomString(MAX_AUTHOR_NAME_LENGTH),
+				getRandomBytes(MAX_PUBLIC_KEY_LENGTH), verified);
+	}
+
 	public static double getMedian(Collection<? extends Number> samples) {
 		int size = samples.size();
 		if (size == 0) throw new IllegalArgumentException();

bramble-core/src/main/java/org/briarproject/bramble/client/ContactGroupFactoryImpl.java

@@ -39,8 +39,7 @@ class ContactGroupFactoryImpl implements ContactGroupFactory {
 
 	@Override
 	public Group createContactGroup(ClientId clientId, int majorVersion,
-			Contact contact) {
-		AuthorId local = contact.getLocalAuthorId();
+			Contact contact, AuthorId local) {
 		AuthorId remote = contact.getAuthor().getId();
 		byte[] descriptor = createGroupDescriptor(local, remote);
 		return groupFactory.createGroup(clientId, majorVersion, descriptor);

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactExchangeTaskImpl.java

@@ -77,7 +77,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	private volatile LocalAuthor localAuthor;
 	private volatile DuplexTransportConnection conn;
 	private volatile TransportId transportId;
-	private volatile SecretKey masterSecret;
+	private volatile SecretKey masterKey;
 	private volatile boolean alice;
 
 	@Inject
@@ -104,13 +104,13 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	}
 
 	@Override
-	public void startExchange(LocalAuthor localAuthor, SecretKey masterSecret,
+	public void startExchange(LocalAuthor localAuthor, SecretKey masterKey,
 			DuplexTransportConnection conn, TransportId transportId,
 			boolean alice) {
 		this.localAuthor = localAuthor;
 		this.conn = conn;
 		this.transportId = transportId;
-		this.masterSecret = masterSecret;
+		this.masterKey = masterKey;
 		this.alice = alice;
 		start();
 	}
@@ -142,9 +142,9 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		}
 
 		// Derive the header keys for the transport streams
-		SecretKey aliceHeaderKey = crypto.deriveKey(ALICE_KEY_LABEL,
-				masterSecret, new byte[] {PROTOCOL_VERSION});
-		SecretKey bobHeaderKey = crypto.deriveKey(BOB_KEY_LABEL, masterSecret,
+		SecretKey aliceHeaderKey = crypto.deriveKey(ALICE_KEY_LABEL, masterKey,
+				new byte[] {PROTOCOL_VERSION});
+		SecretKey bobHeaderKey = crypto.deriveKey(BOB_KEY_LABEL, masterKey,
 				new byte[] {PROTOCOL_VERSION});
 
 		// Create the readers
@@ -163,9 +163,9 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 						.createRecordWriter(streamWriter.getOutputStream());
 
 		// Derive the nonces to be signed
-		byte[] aliceNonce = crypto.mac(ALICE_NONCE_LABEL, masterSecret,
+		byte[] aliceNonce = crypto.mac(ALICE_NONCE_LABEL, masterKey,
 				new byte[] {PROTOCOL_VERSION});
-		byte[] bobNonce = crypto.mac(BOB_NONCE_LABEL, masterSecret,
+		byte[] bobNonce = crypto.mac(BOB_NONCE_LABEL, masterKey,
 				new byte[] {PROTOCOL_VERSION});
 		byte[] localNonce = alice ? aliceNonce : bobNonce;
 		byte[] remoteNonce = alice ? bobNonce : aliceNonce;
@@ -293,8 +293,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			throws DbException {
 		return db.transactionWithResult(false, txn -> {
 			ContactId contactId = contactManager.addContact(txn, remoteAuthor,
-					localAuthor.getId(), masterSecret, timestamp, alice,
-					true, true);
+					masterKey, timestamp, alice, true, true);
 			transportPropertyManager.addRemoteProperties(txn, contactId,
 					remoteProperties);
 			return contactId;

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactManagerImpl.java

@@ -8,7 +8,6 @@ import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.NoSuchContactException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
@@ -18,7 +17,6 @@ import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.transport.KeyManager;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Random;
@@ -30,8 +28,9 @@ import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
 import static java.util.Collections.emptyList;
-import static org.briarproject.bramble.api.contact.PendingContact.PendingContactState.WAITING_FOR_CONNECTION;
+import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
+import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.OURSELVES;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNKNOWN;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNVERIFIED;
@@ -68,31 +67,31 @@ class ContactManagerImpl implements ContactManager {
 	}
 
 	@Override
-	public ContactId addContact(Transaction txn, Author remote, AuthorId local,
-			SecretKey master, long timestamp, boolean alice, boolean verified,
-			boolean active) throws DbException {
-		ContactId c = db.addContact(txn, remote, local, verified, active);
-		keyManager.addContact(txn, c, master, timestamp, alice, active);
-		Contact contact = db.getContact(txn, c);
-		for (ContactHook hook : hooks) hook.addingContact(txn, contact);
-		return c;
-	}
-
-	@Override
-	public ContactId addContact(Transaction txn, Author remote, AuthorId local,
-			boolean verified, boolean active) throws DbException {
-		ContactId c = db.addContact(txn, remote, local, verified, active);
-		Contact contact = db.getContact(txn, c);
-		for (ContactHook hook : hooks) hook.addingContact(txn, contact);
-		return c;
-	}
-
-	@Override
-	public ContactId addContact(Author remote, AuthorId local, SecretKey master,
+	public ContactId addContact(Transaction txn, Author a, SecretKey rootKey,
 			long timestamp, boolean alice, boolean verified, boolean active)
 			throws DbException {
+		ContactId c = db.addContact(txn, a, verified);
+		keyManager.addContact(txn, c, rootKey, timestamp, alice, active);
+		Contact contact = db.getContact(txn, c);
+		for (ContactHook hook : hooks) hook.addingContact(txn, contact);
+		return c;
+	}
+
+	@Override
+	public ContactId addContact(Transaction txn, Author a, boolean verified)
+			throws DbException {
+		ContactId c = db.addContact(txn, a, verified);
+		Contact contact = db.getContact(txn, c);
+		for (ContactHook hook : hooks) hook.addingContact(txn, contact);
+		return c;
+	}
+
+	@Override
+	public ContactId addContact(Author a, SecretKey rootKey, long timestamp,
+			boolean alice, boolean verified, boolean active)
+			throws DbException {
 		return db.transactionWithResult(false, txn ->
-				addContact(txn, remote, local, master, timestamp, alice,
+				addContact(txn, a, rootKey, timestamp, alice,
 						verified, active));
 	}
 
@@ -123,8 +122,8 @@ class ContactManagerImpl implements ContactManager {
 	public PendingContact addRemoteContactRequest(String link, String alias) {
 		// TODO replace with real implementation
 		PendingContactId id = new PendingContactId(link.getBytes());
-		return new PendingContact(id, alias, WAITING_FOR_CONNECTION,
-				System.currentTimeMillis());
+		return new PendingContact(id, new byte[MAX_PUBLIC_KEY_LENGTH], alias,
+				WAITING_FOR_CONNECTION, System.currentTimeMillis());
 	}
 
 	@Override
@@ -144,32 +143,18 @@ class ContactManagerImpl implements ContactManager {
 	}
 
 	@Override
-	public Contact getContact(AuthorId remoteAuthorId, AuthorId localAuthorId)
-			throws DbException {
-		return db.transactionWithResult(true, txn ->
-				getContact(txn, remoteAuthorId, localAuthorId));
+	public Contact getContact(AuthorId a) throws DbException {
+		return db.transactionWithResult(true, txn -> getContact(txn, a));
 	}
 
 	@Override
-	public Contact getContact(Transaction txn, AuthorId remoteAuthorId,
-			AuthorId localAuthorId) throws DbException {
-		Collection<Contact> contacts =
-				db.getContactsByAuthorId(txn, remoteAuthorId);
-		for (Contact c : contacts) {
-			if (c.getLocalAuthorId().equals(localAuthorId)) {
-				return c;
-			}
-		}
-		throw new NoSuchContactException();
+	public Contact getContact(Transaction txn, AuthorId a) throws DbException {
+		return db.getContact(txn, a);
 	}
 
 	@Override
-	public Collection<Contact> getActiveContacts() throws DbException {
-		Collection<Contact> contacts =
-				db.transactionWithResult(true, db::getContacts);
-		List<Contact> active = new ArrayList<>(contacts.size());
-		for (Contact c : contacts) if (c.isActive()) active.add(c);
-		return active;
+	public Collection<Contact> getContacts() throws DbException {
+		return db.transactionWithResult(true, db::getContacts);
 	}
 
 	@Override
@@ -177,12 +162,6 @@ class ContactManagerImpl implements ContactManager {
 		db.transaction(false, txn -> removeContact(txn, c));
 	}
 
-	@Override
-	public void setContactActive(Transaction txn, ContactId c, boolean active)
-			throws DbException {
-		db.setContactActive(txn, c, active);
-	}
-
 	@Override
 	public void setContactAlias(Transaction txn, ContactId c,
 			@Nullable String alias) throws DbException {
@@ -201,16 +180,14 @@ class ContactManagerImpl implements ContactManager {
 	}
 
 	@Override
-	public boolean contactExists(Transaction txn, AuthorId remoteAuthorId,
-			AuthorId localAuthorId) throws DbException {
-		return db.containsContact(txn, remoteAuthorId, localAuthorId);
+	public boolean contactExists(Transaction txn, AuthorId a)
+			throws DbException {
+		return db.containsContact(txn, a);
 	}
 
 	@Override
-	public boolean contactExists(AuthorId remoteAuthorId,
-			AuthorId localAuthorId) throws DbException {
-		return db.transactionWithResult(true, txn ->
-				contactExists(txn, remoteAuthorId, localAuthorId));
+	public boolean contactExists(AuthorId a) throws DbException {
+		return db.transactionWithResult(true, txn -> contactExists(txn, a));
 	}
 
 	@Override
@@ -232,12 +209,12 @@ class ContactManagerImpl implements ContactManager {
 		LocalAuthor localAuthor = identityManager.getLocalAuthor(txn);
 		if (localAuthor.getId().equals(authorId))
 			return new AuthorInfo(OURSELVES);
-		Collection<Contact> contacts = db.getContactsByAuthorId(txn, authorId);
-		if (contacts.isEmpty()) return new AuthorInfo(UNKNOWN);
-		if (contacts.size() > 1) throw new AssertionError();
-		Contact c = contacts.iterator().next();
-		if (c.isVerified()) return new AuthorInfo(VERIFIED, c.getAlias());
-		else return new AuthorInfo(UNVERIFIED, c.getAlias());
+		if (db.containsContact(txn, authorId)) {
+			Contact c = db.getContact(txn, authorId);
+			if (c.isVerified()) return new AuthorInfo(VERIFIED, c.getAlias());
+			else return new AuthorInfo(UNVERIFIED, c.getAlias());
+		}
+		return new AuthorInfo(UNKNOWN);
 	}
 
 }

bramble-core/src/main/java/org/briarproject/bramble/crypto/TransportCryptoImpl.java

@@ -4,18 +4,22 @@ import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.TransportCrypto;
 import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
 import org.briarproject.bramble.api.transport.IncomingKeys;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
 import org.briarproject.bramble.api.transport.TransportKeys;
-import org.briarproject.bramble.util.ByteUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.spongycastle.crypto.Digest;
 import org.spongycastle.crypto.digests.Blake2bDigest;
 
 import javax.inject.Inject;
 
+import static java.lang.System.arraycopy;
+import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_HANDSHAKE_HEADER_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_HANDSHAKE_TAG_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_HEADER_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_TAG_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.BOB_HANDSHAKE_HEADER_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.BOB_HANDSHAKE_TAG_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.BOB_HEADER_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.BOB_TAG_LABEL;
 import static org.briarproject.bramble.api.transport.TransportConstants.ROTATE_LABEL;
@@ -24,6 +28,9 @@ import static org.briarproject.bramble.util.ByteUtils.INT_16_BYTES;
 import static org.briarproject.bramble.util.ByteUtils.INT_64_BYTES;
 import static org.briarproject.bramble.util.ByteUtils.MAX_16_BIT_UNSIGNED;
 import static org.briarproject.bramble.util.ByteUtils.MAX_32_BIT_UNSIGNED;
+import static org.briarproject.bramble.util.ByteUtils.writeUint16;
+import static org.briarproject.bramble.util.ByteUtils.writeUint64;
+import static org.briarproject.bramble.util.StringUtils.toUtf8;
 
 class TransportCryptoImpl implements TransportCrypto {
 
@@ -36,45 +43,44 @@ class TransportCryptoImpl implements TransportCrypto {
 
 	@Override
 	public TransportKeys deriveTransportKeys(TransportId t,
-			SecretKey master, long rotationPeriod, boolean alice,
+			SecretKey rootKey, long timePeriod, boolean weAreAlice,
 			boolean active) {
-		// Keys for the previous period are derived from the master secret
-		SecretKey inTagPrev = deriveTagKey(master, t, !alice);
-		SecretKey inHeaderPrev = deriveHeaderKey(master, t, !alice);
-		SecretKey outTagPrev = deriveTagKey(master, t, alice);
-		SecretKey outHeaderPrev = deriveHeaderKey(master, t, alice);
+		// Keys for the previous period are derived from the root key
+		SecretKey inTagPrev = deriveTagKey(rootKey, t, !weAreAlice);
+		SecretKey inHeaderPrev = deriveHeaderKey(rootKey, t, !weAreAlice);
+		SecretKey outTagPrev = deriveTagKey(rootKey, t, weAreAlice);
+		SecretKey outHeaderPrev = deriveHeaderKey(rootKey, t, weAreAlice);
 		// Derive the keys for the current and next periods
-		SecretKey inTagCurr = rotateKey(inTagPrev, rotationPeriod);
-		SecretKey inHeaderCurr = rotateKey(inHeaderPrev, rotationPeriod);
-		SecretKey inTagNext = rotateKey(inTagCurr, rotationPeriod + 1);
-		SecretKey inHeaderNext = rotateKey(inHeaderCurr, rotationPeriod + 1);
-		SecretKey outTagCurr = rotateKey(outTagPrev, rotationPeriod);
-		SecretKey outHeaderCurr = rotateKey(outHeaderPrev, rotationPeriod);
+		SecretKey inTagCurr = rotateKey(inTagPrev, timePeriod);
+		SecretKey inHeaderCurr = rotateKey(inHeaderPrev, timePeriod);
+		SecretKey inTagNext = rotateKey(inTagCurr, timePeriod + 1);
+		SecretKey inHeaderNext = rotateKey(inHeaderCurr, timePeriod + 1);
+		SecretKey outTagCurr = rotateKey(outTagPrev, timePeriod);
+		SecretKey outHeaderCurr = rotateKey(outHeaderPrev, timePeriod);
 		// Initialise the reordering windows and stream counters
 		IncomingKeys inPrev = new IncomingKeys(inTagPrev, inHeaderPrev,
-				rotationPeriod - 1);
+				timePeriod - 1);
 		IncomingKeys inCurr = new IncomingKeys(inTagCurr, inHeaderCurr,
-				rotationPeriod);
+				timePeriod);
 		IncomingKeys inNext = new IncomingKeys(inTagNext, inHeaderNext,
-				rotationPeriod + 1);
+				timePeriod + 1);
 		OutgoingKeys outCurr = new OutgoingKeys(outTagCurr, outHeaderCurr,
-				rotationPeriod, active);
+				timePeriod, active);
 		// Collect and return the keys
 		return new TransportKeys(t, inPrev, inCurr, inNext, outCurr);
 	}
 
 	@Override
-	public TransportKeys rotateTransportKeys(TransportKeys k,
-			long rotationPeriod) {
-		if (k.getRotationPeriod() >= rotationPeriod) return k;
+	public TransportKeys rotateTransportKeys(TransportKeys k, long timePeriod) {
+		if (k.getTimePeriod() >= timePeriod) return k;
 		IncomingKeys inPrev = k.getPreviousIncomingKeys();
 		IncomingKeys inCurr = k.getCurrentIncomingKeys();
 		IncomingKeys inNext = k.getNextIncomingKeys();
 		OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
-		long startPeriod = outCurr.getRotationPeriod();
+		long startPeriod = outCurr.getTimePeriod();
 		boolean active = outCurr.isActive();
 		// Rotate the keys
-		for (long p = startPeriod + 1; p <= rotationPeriod; p++) {
+		for (long p = startPeriod + 1; p <= timePeriod; p++) {
 			inPrev = inCurr;
 			inCurr = inNext;
 			SecretKey inNextTag = rotateKey(inNext.getTagKey(), p + 1);
@@ -89,24 +95,117 @@ class TransportCryptoImpl implements TransportCrypto {
 				outCurr);
 	}
 
-	private SecretKey rotateKey(SecretKey k, long rotationPeriod) {
+	private SecretKey rotateKey(SecretKey k, long timePeriod) {
 		byte[] period = new byte[INT_64_BYTES];
-		ByteUtils.writeUint64(rotationPeriod, period, 0);
+		writeUint64(timePeriod, period, 0);
 		return crypto.deriveKey(ROTATE_LABEL, k, period);
 	}
 
-	private SecretKey deriveTagKey(SecretKey master, TransportId t,
-			boolean alice) {
-		String label = alice ? ALICE_TAG_LABEL : BOB_TAG_LABEL;
-		byte[] id = StringUtils.toUtf8(t.getString());
-		return crypto.deriveKey(label, master, id);
+	private SecretKey deriveTagKey(SecretKey rootKey, TransportId t,
+			boolean keyBelongsToAlice) {
+		String label = keyBelongsToAlice ? ALICE_TAG_LABEL : BOB_TAG_LABEL;
+		byte[] id = toUtf8(t.getString());
+		return crypto.deriveKey(label, rootKey, id);
 	}
 
-	private SecretKey deriveHeaderKey(SecretKey master, TransportId t,
-			boolean alice) {
-		String label = alice ? ALICE_HEADER_LABEL : BOB_HEADER_LABEL;
-		byte[] id = StringUtils.toUtf8(t.getString());
-		return crypto.deriveKey(label, master, id);
+	private SecretKey deriveHeaderKey(SecretKey rootKey, TransportId t,
+			boolean keyBelongsToAlice) {
+		String label = keyBelongsToAlice ? ALICE_HEADER_LABEL :
+				BOB_HEADER_LABEL;
+		byte[] id = toUtf8(t.getString());
+		return crypto.deriveKey(label, rootKey, id);
+	}
+
+	@Override
+	public HandshakeKeys deriveHandshakeKeys(TransportId t, SecretKey rootKey,
+			long timePeriod, boolean weAreAlice) {
+		if (timePeriod < 1) throw new IllegalArgumentException();
+		IncomingKeys inPrev = deriveIncomingHandshakeKeys(t, rootKey,
+				weAreAlice, timePeriod - 1);
+		IncomingKeys inCurr = deriveIncomingHandshakeKeys(t, rootKey,
+				weAreAlice, timePeriod);
+		IncomingKeys inNext = deriveIncomingHandshakeKeys(t, rootKey,
+				weAreAlice, timePeriod + 1);
+		OutgoingKeys outCurr = deriveOutgoingHandshakeKeys(t, rootKey,
+				weAreAlice, timePeriod);
+		return new HandshakeKeys(t, inPrev, inCurr, inNext, outCurr, rootKey,
+				weAreAlice);
+	}
+
+	private IncomingKeys deriveIncomingHandshakeKeys(TransportId t,
+			SecretKey rootKey, boolean weAreAlice, long timePeriod) {
+		SecretKey tag = deriveHandshakeTagKey(t, rootKey, !weAreAlice,
+				timePeriod);
+		SecretKey header = deriveHandshakeHeaderKey(t, rootKey, !weAreAlice,
+				timePeriod);
+		return new IncomingKeys(tag, header, timePeriod);
+	}
+
+	private OutgoingKeys deriveOutgoingHandshakeKeys(TransportId t,
+			SecretKey rootKey, boolean weAreAlice, long timePeriod) {
+		SecretKey tag = deriveHandshakeTagKey(t, rootKey, weAreAlice,
+				timePeriod);
+		SecretKey header = deriveHandshakeHeaderKey(t, rootKey, weAreAlice,
+				timePeriod);
+		return new OutgoingKeys(tag, header, timePeriod, true);
+	}
+
+	private SecretKey deriveHandshakeTagKey(TransportId t, SecretKey rootKey,
+			boolean keyBelongsToAlice, long timePeriod) {
+		String label = keyBelongsToAlice ? ALICE_HANDSHAKE_TAG_LABEL :
+				BOB_HANDSHAKE_TAG_LABEL;
+		byte[] id = toUtf8(t.getString());
+		byte[] period = new byte[INT_64_BYTES];
+		writeUint64(timePeriod, period, 0);
+		return crypto.deriveKey(label, rootKey, id, period);
+	}
+
+	private SecretKey deriveHandshakeHeaderKey(TransportId t, SecretKey rootKey,
+			boolean keyBelongsToAlice, long timePeriod) {
+		String label = keyBelongsToAlice ? ALICE_HANDSHAKE_HEADER_LABEL :
+				BOB_HANDSHAKE_HEADER_LABEL;
+		byte[] id = toUtf8(t.getString());
+		byte[] period = new byte[INT_64_BYTES];
+		writeUint64(timePeriod, period, 0);
+		return crypto.deriveKey(label, rootKey, id, period);
+	}
+
+	@Override
+	public HandshakeKeys updateHandshakeKeys(HandshakeKeys k, long timePeriod) {
+		long elapsed = timePeriod - k.getTimePeriod();
+		TransportId t = k.getTransportId();
+		SecretKey rootKey = k.getRootKey();
+		boolean weAreAlice = k.isAlice();
+		if (elapsed <= 0) {
+			// The keys are for the given period or later - don't update them
+			return k;
+		} else if (elapsed == 1) {
+			// The keys are one period old - shift by one period, keeping the
+			// reordering windows for keys we retain
+			IncomingKeys inPrev = k.getCurrentIncomingKeys();
+			IncomingKeys inCurr = k.getNextIncomingKeys();
+			IncomingKeys inNext = deriveIncomingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod + 1);
+			OutgoingKeys outCurr = deriveOutgoingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod);
+			return new HandshakeKeys(t, inPrev, inCurr, inNext, outCurr,
+					rootKey, weAreAlice);
+		} else if (elapsed == 2) {
+			// The keys are two periods old - shift by two periods, keeping
+			// the reordering windows for keys we retain
+			IncomingKeys inPrev = k.getNextIncomingKeys();
+			IncomingKeys inCurr = deriveIncomingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod);
+			IncomingKeys inNext = deriveIncomingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod + 1);
+			OutgoingKeys outCurr = deriveOutgoingHandshakeKeys(t, rootKey,
+					weAreAlice, timePeriod);
+			return new HandshakeKeys(t, inPrev, inCurr, inNext, outCurr,
+					rootKey, weAreAlice);
+		} else {
+			// The keys are more than two periods old - derive fresh keys
+			return deriveHandshakeKeys(t, rootKey, timePeriod, weAreAlice);
+		}
 	}
 
 	@Override
@@ -125,14 +224,14 @@ class TransportCryptoImpl implements TransportCrypto {
 		// The input is the protocol version as a 16-bit integer, followed by
 		// the stream number as a 64-bit integer
 		byte[] protocolVersionBytes = new byte[INT_16_BYTES];
-		ByteUtils.writeUint16(protocolVersion, protocolVersionBytes, 0);
+		writeUint16(protocolVersion, protocolVersionBytes, 0);
 		prf.update(protocolVersionBytes, 0, protocolVersionBytes.length);
 		byte[] streamNumberBytes = new byte[INT_64_BYTES];
-		ByteUtils.writeUint64(streamNumber, streamNumberBytes, 0);
+		writeUint64(streamNumber, streamNumberBytes, 0);
 		prf.update(streamNumberBytes, 0, streamNumberBytes.length);
 		byte[] mac = new byte[macLength];
 		prf.doFinal(mac, 0);
 		// The output is the first TAG_LENGTH bytes of the MAC
-		System.arraycopy(mac, 0, tag, 0, TAG_LENGTH);
+		arraycopy(mac, 0, tag, 0, TAG_LENGTH);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/db/Database.java

@@ -2,9 +2,13 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DataTooNewException;
 import org.briarproject.bramble.api.db.DataTooOldException;
+import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.MessageDeletedException;
 import org.briarproject.bramble.api.db.Metadata;
@@ -23,8 +27,11 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.validation.MessageState;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeySet;
+import org.briarproject.bramble.api.transport.HandshakeKeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.Collection;
@@ -33,11 +40,14 @@ import java.util.Map;
 import javax.annotation.Nullable;
 
 /**
- * A low-level interface to the database (DatabaseComponent provides a
- * high-level interface). Most operations take a transaction argument, which is
- * obtained by calling {@link #startTransaction()}. Every transaction must be
- * terminated by calling either {@link #abortTransaction(Object) abortTransaction(T)} or
- * {@link #commitTransaction(Object) commitTransaction(T)}, even if an exception is thrown.
+ * A low-level interface to the database ({@link DatabaseComponent} provides a
+ * high-level interface).
+ * <p/>
+ * Most operations take a transaction argument, which is obtained by calling
+ * {@link #startTransaction()}. Every transaction must be terminated by calling
+ * either {@link #abortTransaction(Object) abortTransaction(T)} or
+ * {@link #commitTransaction(Object) commitTransaction(T)}, even if an
+ * exception is thrown.
  */
 @NotNullByDefault
 interface Database<T> {
@@ -77,11 +87,10 @@ interface Database<T> {
 	void commitTransaction(T txn) throws DbException;
 
 	/**
-	 * Stores a contact associated with the given local and remote pseudonyms,
-	 * and returns an ID for the contact.
+	 * Stores a contact with the given pseudonym and returns an ID for the
+	 * contact.
 	 */
-	ContactId addContact(T txn, Author remote, AuthorId local, boolean verified,
-			boolean active) throws DbException;
+	ContactId addContact(T txn, Author a, boolean verified) throws DbException;
 
 	/**
 	 * Stores a group.
@@ -95,6 +104,20 @@ interface Database<T> {
 	void addGroupVisibility(T txn, ContactId c, GroupId g, boolean shared)
 			throws DbException;
 
+	/**
+	 * Stores the given handshake keys for the given contact and returns a
+	 * key set ID.
+	 */
+	HandshakeKeySetId addHandshakeKeys(T txn, ContactId c, HandshakeKeys k)
+			throws DbException;
+
+	/**
+	 * Stores the given handshake keys for the given pending contact and
+	 * returns a key set ID.
+	 */
+	HandshakeKeySetId addHandshakeKeys(T txn, PendingContactId p,
+			HandshakeKeys k) throws DbException;
+
 	/**
 	 * Stores a local pseudonym.
 	 */
@@ -121,6 +144,11 @@ interface Database<T> {
 	 */
 	void addOfferedMessage(T txn, ContactId c, MessageId m) throws DbException;
 
+	/**
+	 * Stores a pending contact.
+	 */
+	void addPendingContact(T txn, PendingContact p) throws DbException;
+
 	/**
 	 * Stores a transport.
 	 */
@@ -131,17 +159,15 @@ interface Database<T> {
 	 * Stores the given transport keys for the given contact and returns a
 	 * key set ID.
 	 */
-	KeySetId addTransportKeys(T txn, ContactId c, TransportKeys k)
+	TransportKeySetId addTransportKeys(T txn, ContactId c, TransportKeys k)
 			throws DbException;
 
 	/**
-	 * Returns true if the database contains the given contact for the given
-	 * local pseudonym.
+	 * Returns true if the database contains the given contact.
 	 * <p/>
 	 * Read-only.
 	 */
-	boolean containsContact(T txn, AuthorId remote, AuthorId local)
-			throws DbException;
+	boolean containsContact(T txn, AuthorId a) throws DbException;
 
 	/**
 	 * Returns true if the database contains the given contact.
@@ -171,6 +197,14 @@ interface Database<T> {
 	 */
 	boolean containsMessage(T txn, MessageId m) throws DbException;
 
+	/**
+	 * Returns true if the database contains the given pending contact.
+	 * <p/>
+	 * Read-only.
+	 */
+	boolean containsPendingContact(T txn, PendingContactId p)
+			throws DbException;
+
 	/**
 	 * Returns true if the database contains the given transport.
 	 * <p/>
@@ -215,6 +249,13 @@ interface Database<T> {
 	 */
 	Contact getContact(T txn, ContactId c) throws DbException;
 
+	/**
+	 * Returns the contact with the given author ID.
+	 * <p/>
+	 * Read-only.
+	 */
+	Contact getContact(T txn, AuthorId a) throws DbException;
+
 	/**
 	 * Returns all contacts.
 	 * <p/>
@@ -222,28 +263,6 @@ interface Database<T> {
 	 */
 	Collection<Contact> getContacts(T txn) throws DbException;
 
-	/**
-	 * Returns a possibly empty collection of contacts with the given author ID.
-	 * <p/>
-	 * Read-only.
-	 */
-	Collection<Contact> getContactsByAuthorId(T txn, AuthorId remote)
-			throws DbException;
-
-	/**
-	 * Returns all contacts associated with the given local pseudonym.
-	 * <p/>
-	 * Read-only.
-	 */
-	Collection<ContactId> getContacts(T txn, AuthorId a) throws DbException;
-
-	/**
-	 * Returns the amount of free storage space available to the database, in
-	 * bytes. This is based on the minimum of the space available on the device
-	 * where the database is stored and the database's configured size.
-	 */
-	long getFreeSpace() throws DbException;
-
 	/**
 	 * Returns the group with the given ID.
 	 * <p/>
@@ -284,6 +303,14 @@ interface Database<T> {
 	Map<ContactId, Boolean> getGroupVisibility(T txn, GroupId g)
 			throws DbException;
 
+	/**
+	 * Returns all handshake keys for the given transport.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<HandshakeKeySet> getHandshakeKeys(T txn, TransportId t)
+			throws DbException;
+
 	/**
 	 * Returns the local pseudonym with the given ID.
 	 * <p/>
@@ -474,6 +501,13 @@ interface Database<T> {
 	 */
 	long getNextSendTime(T txn, ContactId c) throws DbException;
 
+	/**
+	 * Returns all pending contacts.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<PendingContact> getPendingContacts(T txn) throws DbException;
+
 	/**
 	 * Returns the IDs of some messages that are eligible to be sent to the
 	 * given contact and have been requested by the contact, up to the given
@@ -496,13 +530,19 @@ interface Database<T> {
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<KeySet> getTransportKeys(T txn, TransportId t)
+	Collection<TransportKeySet> getTransportKeys(T txn, TransportId t)
+			throws DbException;
+
+	/**
+	 * Increments the outgoing stream counter for the given handshake keys.
+	 */
+	void incrementStreamCounter(T txn, TransportId t, HandshakeKeySetId k)
 			throws DbException;
 
 	/**
 	 * Increments the outgoing stream counter for the given transport keys.
 	 */
-	void incrementStreamCounter(T txn, TransportId t, KeySetId k)
+	void incrementStreamCounter(T txn, TransportId t, TransportKeySetId k)
 			throws DbException;
 
 	/**
@@ -571,6 +611,12 @@ interface Database<T> {
 	void removeGroupVisibility(T txn, ContactId c, GroupId g)
 			throws DbException;
 
+	/**
+	 * Removes the given handshake keys from the database.
+	 */
+	void removeHandshakeKeys(T txn, TransportId t, HandshakeKeySetId k)
+			throws DbException;
+
 	/**
 	 * Removes a local pseudonym (and all associated state) from the database.
 	 */
@@ -588,6 +634,11 @@ interface Database<T> {
 	void removeOfferedMessages(T txn, ContactId c,
 			Collection<MessageId> requested) throws DbException;
 
+	/**
+	 * Removes a pending contact (and all associated state) from the database.
+	 */
+	void removePendingContact(T txn, PendingContactId p) throws DbException;
+
 	/**
 	 * Removes a transport (and all associated state) from the database.
 	 */
@@ -596,7 +647,7 @@ interface Database<T> {
 	/**
 	 * Removes the given transport keys from the database.
 	 */
-	void removeTransportKeys(T txn, TransportId t, KeySetId k)
+	void removeTransportKeys(T txn, TransportId t, TransportKeySetId k)
 			throws DbException;
 
 	/**
@@ -610,12 +661,6 @@ interface Database<T> {
 	 */
 	void setContactVerified(T txn, ContactId c) throws DbException;
 
-	/**
-	 * Marks the given contact as active or inactive.
-	 */
-	void setContactActive(T txn, ContactId c, boolean active)
-			throws DbException;
-
 	/**
 	 * Sets an alias name for a contact.
 	 */
@@ -641,16 +686,29 @@ interface Database<T> {
 			throws DbException;
 
 	/**
-	 * Sets the reordering window for the given key set and transport in the
-	 * given rotation period.
+	 * Sets the state of the given pending contact.
 	 */
-	void setReorderingWindow(T txn, KeySetId k, TransportId t,
-			long rotationPeriod, long base, byte[] bitmap) throws DbException;
+	void setPendingContactState(T txn, PendingContactId p,
+			PendingContactState state) throws DbException;
+
+	/**
+	 * Sets the reordering window for the given transport key set in the given
+	 * time period.
+	 */
+	void setReorderingWindow(T txn, TransportKeySetId k, TransportId t,
+			long timePeriod, long base, byte[] bitmap) throws DbException;
+
+	/**
+	 * Sets the reordering window for the given handshake key set in the given
+	 * time period.
+	 */
+	void setReorderingWindow(T txn, HandshakeKeySetId k, TransportId t,
+			long timePeriod, long base, byte[] bitmap) throws DbException;
 
 	/**
 	 * Marks the given transport keys as usable for outgoing streams.
 	 */
-	void setTransportKeysActive(T txn, TransportId t, KeySetId k)
+	void setTransportKeysActive(T txn, TransportId t, TransportKeySetId k)
 			throws DbException;
 
 	/**
@@ -661,8 +719,13 @@ interface Database<T> {
 	void updateExpiryTimeAndEta(T txn, ContactId c, MessageId m, int maxLatency)
 			throws DbException;
 
+	/**
+	 * Updates the given handshake keys.
+	 */
+	void updateHandshakeKeys(T txn, HandshakeKeySet ks) throws DbException;
+
 	/**
 	 * Updates the given transport keys following key rotation.
 	 */
-	void updateTransportKeys(T txn, KeySet ks) throws DbException;
+	void updateTransportKeys(T txn, TransportKeySet ks) throws DbException;
 }

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseComponentImpl.java

@@ -2,27 +2,34 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
-import org.briarproject.bramble.api.contact.event.ContactStatusChangedEvent;
 import org.briarproject.bramble.api.contact.event.ContactVerifiedEvent;
 import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.db.CommitAction;
+import org.briarproject.bramble.api.db.CommitAction.Visitor;
 import org.briarproject.bramble.api.db.ContactExistsException;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbCallable;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.DbRunnable;
+import org.briarproject.bramble.api.db.EventAction;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.db.NoSuchContactException;
 import org.briarproject.bramble.api.db.NoSuchGroupException;
 import org.briarproject.bramble.api.db.NoSuchLocalAuthorException;
 import org.briarproject.bramble.api.db.NoSuchMessageException;
+import org.briarproject.bramble.api.db.NoSuchPendingContactException;
 import org.briarproject.bramble.api.db.NoSuchTransportException;
 import org.briarproject.bramble.api.db.NullableDbCallable;
+import org.briarproject.bramble.api.db.PendingContactExistsException;
+import org.briarproject.bramble.api.db.TaskAction;
 import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.identity.LocalAuthor;
@@ -55,8 +62,11 @@ import org.briarproject.bramble.api.sync.event.MessageToRequestEvent;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
 import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
 import org.briarproject.bramble.api.sync.validation.MessageState;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeySet;
+import org.briarproject.bramble.api.transport.HandshakeKeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.ArrayList;
@@ -64,6 +74,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.logging.Logger;
@@ -92,25 +103,29 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	private final Database<T> db;
 	private final Class<T> txnClass;
 	private final EventBus eventBus;
-	private final ShutdownManager shutdown;
+	private final Executor eventExecutor;
+	private final ShutdownManager shutdownManager;
 	private final AtomicBoolean closed = new AtomicBoolean(false);
 	private final ReentrantReadWriteLock lock =
 			new ReentrantReadWriteLock(true);
+	private final Visitor visitor = new CommitActionVisitor();
 
 	@Inject
 	DatabaseComponentImpl(Database<T> db, Class<T> txnClass, EventBus eventBus,
-			ShutdownManager shutdown) {
+			@EventExecutor Executor eventExecutor,
+			ShutdownManager shutdownManager) {
 		this.db = db;
 		this.txnClass = txnClass;
 		this.eventBus = eventBus;
-		this.shutdown = shutdown;
+		this.eventExecutor = eventExecutor;
+		this.shutdownManager = shutdownManager;
 	}
 
 	@Override
 	public boolean open(SecretKey key, @Nullable MigrationListener listener)
 			throws DbException {
 		boolean reopened = db.open(key, listener);
-		shutdown.addShutdownHook(() -> {
+		shutdownManager.addShutdownHook(() -> {
 			try {
 				close();
 			} catch (DbException e) {
@@ -160,13 +175,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	public void endTransaction(Transaction transaction) {
 		try {
 			T txn = txnClass.cast(transaction.unbox());
-			if (!transaction.isCommitted()) db.abortTransaction(txn);
+			if (transaction.isCommitted()) {
+				for (CommitAction a : transaction.getActions())
+					a.accept(visitor);
+			} else {
+				db.abortTransaction(txn);
+			}
 		} finally {
 			if (transaction.isReadOnly()) lock.readLock().unlock();
 			else lock.writeLock().unlock();
 		}
-		if (transaction.isCommitted())
-			for (Event e : transaction.getEvents()) eventBus.broadcast(e);
 	}
 
 	@Override
@@ -214,20 +232,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public ContactId addContact(Transaction transaction, Author remote,
-			AuthorId local, boolean verified, boolean active)
-			throws DbException {
+	public ContactId addContact(Transaction transaction, Author a,
+			boolean verified) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
-		if (!db.containsLocalAuthor(txn, local))
-			throw new NoSuchLocalAuthorException();
-		if (db.containsLocalAuthor(txn, remote.getId()))
+		if (db.containsLocalAuthor(txn, a.getId()))
 			throw new ContactExistsException();
-		if (db.containsContact(txn, remote.getId(), local))
+		if (db.containsContact(txn, a.getId()))
 			throw new ContactExistsException();
-		ContactId c = db.addContact(txn, remote, local, verified, active);
-		transaction.attach(new ContactAddedEvent(c, active));
-		if (active) transaction.attach(new ContactStatusChangedEvent(c, true));
+		ContactId c = db.addContact(txn, a, verified);
+		transaction.attach(new ContactAddedEvent(c));
 		return c;
 	}
 
@@ -241,6 +255,30 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		}
 	}
 
+	@Override
+	public HandshakeKeySetId addHandshakeKeys(Transaction transaction,
+			ContactId c, HandshakeKeys k) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsContact(txn, c))
+			throw new NoSuchContactException();
+		if (!db.containsTransport(txn, k.getTransportId()))
+			throw new NoSuchTransportException();
+		return db.addHandshakeKeys(txn, c, k);
+	}
+
+	@Override
+	public HandshakeKeySetId addHandshakeKeys(Transaction transaction,
+			PendingContactId p, HandshakeKeys k) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsPendingContact(txn, p))
+			throw new NoSuchPendingContactException();
+		if (!db.containsTransport(txn, k.getTransportId()))
+			throw new NoSuchTransportException();
+		return db.addHandshakeKeys(txn, p, k);
+	}
+
 	@Override
 	public void addLocalAuthor(Transaction transaction, LocalAuthor a)
 			throws DbException {
@@ -269,6 +307,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.mergeMessageMetadata(txn, m.getId(), meta);
 	}
 
+	@Override
+	public void addPendingContact(Transaction transaction, PendingContact p)
+			throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (db.containsPendingContact(txn, p.getId()))
+			throw new PendingContactExistsException();
+		db.addPendingContact(txn, p);
+	}
+
 	@Override
 	public void addTransport(Transaction transaction, TransportId t,
 			int maxLatency) throws DbException {
@@ -279,8 +327,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public KeySetId addTransportKeys(Transaction transaction, ContactId c,
-			TransportKeys k) throws DbException {
+	public TransportKeySetId addTransportKeys(Transaction transaction,
+			ContactId c, TransportKeys k) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
@@ -291,12 +339,10 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public boolean containsContact(Transaction transaction, AuthorId remote,
-			AuthorId local) throws DbException {
+	public boolean containsContact(Transaction transaction, AuthorId a)
+			throws DbException {
 		T txn = unbox(transaction);
-		if (!db.containsLocalAuthor(txn, local))
-			throw new NoSuchLocalAuthorException();
-		return db.containsContact(txn, remote, local);
+		return db.containsContact(txn, a);
 	}
 
 	@Override
@@ -313,6 +359,13 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.containsLocalAuthor(txn, local);
 	}
 
+	@Override
+	public boolean containsPendingContact(Transaction transaction,
+			PendingContactId p) throws DbException {
+		T txn = unbox(transaction);
+		return db.containsPendingContact(txn, p);
+	}
+
 	@Override
 	public void deleteMessage(Transaction transaction, MessageId m)
 			throws DbException {
@@ -429,6 +482,15 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getContact(txn, c);
 	}
 
+	@Override
+	public Contact getContact(Transaction transaction, AuthorId a)
+			throws DbException {
+		T txn = unbox(transaction);
+		if (!db.containsContact(txn, a))
+			throw new NoSuchContactException();
+		return db.getContact(txn, a);
+	}
+
 	@Override
 	public Collection<Contact> getContacts(Transaction transaction)
 			throws DbException {
@@ -436,22 +498,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getContacts(txn);
 	}
 
-	@Override
-	public Collection<Contact> getContactsByAuthorId(Transaction transaction,
-			AuthorId remote) throws DbException {
-		T txn = unbox(transaction);
-		return db.getContactsByAuthorId(txn, remote);
-	}
-
-	@Override
-	public Collection<ContactId> getContacts(Transaction transaction,
-			AuthorId a) throws DbException {
-		T txn = unbox(transaction);
-		if (!db.containsLocalAuthor(txn, a))
-			throw new NoSuchLocalAuthorException();
-		return db.getContacts(txn, a);
-	}
-
 	@Override
 	public Group getGroup(Transaction transaction, GroupId g)
 			throws DbException {
@@ -486,6 +532,15 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getGroupVisibility(txn, c, g);
 	}
 
+	@Override
+	public Collection<HandshakeKeySet> getHandshakeKeys(Transaction transaction,
+			TransportId t) throws DbException {
+		T txn = unbox(transaction);
+		if (!db.containsTransport(txn, t))
+			throw new NoSuchTransportException();
+		return db.getHandshakeKeys(txn, t);
+	}
+
 	@Override
 	public LocalAuthor getLocalAuthor(Transaction transaction, AuthorId a)
 			throws DbException {
@@ -643,6 +698,13 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getNextSendTime(txn, c);
 	}
 
+	@Override
+	public Collection<PendingContact> getPendingContacts(
+			Transaction transaction) throws DbException {
+		T txn = unbox(transaction);
+		return db.getPendingContacts(txn);
+	}
+
 	@Override
 	public Settings getSettings(Transaction transaction, String namespace)
 			throws DbException {
@@ -651,7 +713,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public Collection<KeySet> getTransportKeys(Transaction transaction,
+	public Collection<TransportKeySet> getTransportKeys(Transaction transaction,
 			TransportId t) throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
@@ -661,7 +723,17 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 
 	@Override
 	public void incrementStreamCounter(Transaction transaction, TransportId t,
-			KeySetId k) throws DbException {
+			HandshakeKeySetId k) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsTransport(txn, t))
+			throw new NoSuchTransportException();
+		db.incrementStreamCounter(txn, t, k);
+	}
+
+	@Override
+	public void incrementStreamCounter(Transaction transaction, TransportId t,
+			TransportKeySetId k) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
@@ -810,6 +882,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		transaction.attach(new GroupVisibilityUpdatedEvent(affected));
 	}
 
+	@Override
+	public void removeHandshakeKeys(Transaction transaction,
+			TransportId t, HandshakeKeySetId k) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsTransport(txn, t))
+			throw new NoSuchTransportException();
+		db.removeHandshakeKeys(txn, t, k);
+	}
+
 	@Override
 	public void removeLocalAuthor(Transaction transaction, AuthorId a)
 			throws DbException {
@@ -832,6 +914,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.removeMessage(txn, m);
 	}
 
+	@Override
+	public void removePendingContact(Transaction transaction,
+			PendingContactId p) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsPendingContact(txn, p))
+			throw new NoSuchPendingContactException();
+		db.removePendingContact(txn, p);
+	}
+
 	@Override
 	public void removeTransport(Transaction transaction, TransportId t)
 			throws DbException {
@@ -844,7 +936,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 
 	@Override
 	public void removeTransportKeys(Transaction transaction,
-			TransportId t, KeySetId k) throws DbException {
+			TransportId t, TransportKeySetId k) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
@@ -863,17 +955,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		transaction.attach(new ContactVerifiedEvent(c));
 	}
 
-	@Override
-	public void setContactActive(Transaction transaction, ContactId c,
-			boolean active) throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		db.setContactActive(txn, c, active);
-		transaction.attach(new ContactStatusChangedEvent(c, active));
-	}
-
 	@Override
 	public void setContactAlias(Transaction transaction, ContactId c,
 			@Nullable String alias) throws DbException {
@@ -943,19 +1024,30 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public void setReorderingWindow(Transaction transaction, KeySetId k,
-			TransportId t, long rotationPeriod, long base, byte[] bitmap)
-			throws DbException {
+	public void setReorderingWindow(Transaction transaction,
+			TransportKeySetId k, TransportId t, long timePeriod, long base,
+			byte[] bitmap) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
 			throw new NoSuchTransportException();
-		db.setReorderingWindow(txn, k, t, rotationPeriod, base, bitmap);
+		db.setReorderingWindow(txn, k, t, timePeriod, base, bitmap);
+	}
+
+	@Override
+	public void setReorderingWindow(Transaction transaction,
+			HandshakeKeySetId k, TransportId t, long timePeriod, long base,
+			byte[] bitmap) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsTransport(txn, t))
+			throw new NoSuchTransportException();
+		db.setReorderingWindow(txn, k, t, timePeriod, base, bitmap);
 	}
 
 	@Override
 	public void setTransportKeysActive(Transaction transaction, TransportId t,
-			KeySetId k) throws DbException {
+			TransportKeySetId k) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsTransport(txn, t))
@@ -964,14 +1056,39 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public void updateTransportKeys(Transaction transaction,
-			Collection<KeySet> keys) throws DbException {
+	public void updateHandshakeKeys(Transaction transaction,
+			Collection<HandshakeKeySet> keys) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
-		for (KeySet ks : keys) {
-			TransportId t = ks.getTransportKeys().getTransportId();
+		for (HandshakeKeySet ks : keys) {
+			TransportId t = ks.getKeys().getTransportId();
+			if (db.containsTransport(txn, t))
+				db.updateHandshakeKeys(txn, ks);
+		}
+	}
+
+	@Override
+	public void updateTransportKeys(Transaction transaction,
+			Collection<TransportKeySet> keys) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		for (TransportKeySet ks : keys) {
+			TransportId t = ks.getKeys().getTransportId();
 			if (db.containsTransport(txn, t))
 				db.updateTransportKeys(txn, ks);
 		}
 	}
+
+	private class CommitActionVisitor implements Visitor {
+
+		@Override
+		public void visit(EventAction a) {
+			eventBus.broadcast(a.getEvent());
+		}
+
+		@Override
+		public void visit(TaskAction a) {
+			eventExecutor.execute(a.getTask());
+		}
+	}
 }

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseModule.java

@@ -3,11 +3,13 @@ package org.briarproject.bramble.db;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 
 import java.sql.Connection;
+import java.util.concurrent.Executor;
 
 import javax.inject.Singleton;
 
@@ -27,8 +29,9 @@ public class DatabaseModule {
 	@Provides
 	@Singleton
 	DatabaseComponent provideDatabaseComponent(Database<Connection> db,
-			EventBus eventBus, ShutdownManager shutdown) {
+			EventBus eventBus, @EventExecutor Executor eventExecutor,
+			ShutdownManager shutdownManager) {
 		return new DatabaseComponentImpl<>(db, Connection.class, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/db/H2Database.java

@@ -76,30 +76,6 @@ class H2Database extends JdbcDatabase {
 		}
 	}
 
-	@Override
-	public long getFreeSpace() {
-		File dir = config.getDatabaseDirectory();
-		long maxSize = config.getMaxSize();
-		long free = dir.getFreeSpace();
-		long used = getDiskSpace(dir);
-		long quota = maxSize - used;
-		return Math.min(free, quota);
-	}
-
-	private long getDiskSpace(File f) {
-		if (f.isDirectory()) {
-			long total = 0;
-			File[] children = f.listFiles();
-			if (children != null)
-				for (File child : children) total += getDiskSpace(child);
-			return total;
-		} else if (f.isFile()) {
-			return f.length();
-		} else {
-			return 0;
-		}
-	}
-
 	@Override
 	protected Connection createConnection() throws SQLException {
 		SecretKey key = this.key;

bramble-core/src/main/java/org/briarproject/bramble/db/HyperSqlDatabase.java

@@ -86,30 +86,6 @@ class HyperSqlDatabase extends JdbcDatabase {
 		}
 	}
 
-	@Override
-	public long getFreeSpace() {
-		File dir = config.getDatabaseDirectory();
-		long maxSize = config.getMaxSize();
-		long free = dir.getFreeSpace();
-		long used = getDiskSpace(dir);
-		long quota = maxSize - used;
-		return Math.min(free, quota);
-	}
-
-	private long getDiskSpace(File f) {
-		if (f.isDirectory()) {
-			long total = 0;
-			File[] children = f.listFiles();
-			if (children != null)
-				for (File child : children) total += getDiskSpace(child);
-			return total;
-		} else if (f.isFile()) {
-			return f.length();
-		} else {
-			return 0;
-		}
-	}
-
 	@Override
 	protected Connection createConnection() throws SQLException {
 		SecretKey key = this.key;

bramble-core/src/main/java/org/briarproject/bramble/db/Migration40_41.java

@@ -17,7 +17,7 @@ class Migration40_41 implements Migration<Connection> {
 
 	private final DatabaseTypes dbTypes;
 
-	public Migration40_41(DatabaseTypes databaseTypes) {
+	Migration40_41(DatabaseTypes databaseTypes) {
 		this.dbTypes = databaseTypes;
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/db/Migration41_42.java

@@ -0,0 +1,97 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.db.DbException;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
+class Migration41_42 implements Migration<Connection> {
+
+	private static final Logger LOG = getLogger(Migration41_42.class.getName());
+
+	private final DatabaseTypes dbTypes;
+
+	Migration41_42(DatabaseTypes dbTypes) {
+		this.dbTypes = dbTypes;
+	}
+
+	@Override
+	public int getStartVersion() {
+		return 41;
+	}
+
+	@Override
+	public int getEndVersion() {
+		return 42;
+	}
+
+	@Override
+	public void migrate(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			s = txn.createStatement();
+			s.execute("ALTER TABLE outgoingKeys"
+					+ " ALTER COLUMN rotationPeriod"
+					+ " RENAME TO timePeriod");
+			s.execute("ALTER TABLE incomingKeys"
+					+ " ALTER COLUMN rotationPeriod"
+					+ " RENAME TO timePeriod");
+			s.execute("ALTER TABLE incomingKeys"
+					+ " DROP COLUMN contactId");
+			s.execute(dbTypes.replaceTypes("CREATE TABLE pendingContacts"
+					+ " (pendingContactId _HASH NOT NULL,"
+					+ " publicKey _BINARY NOT NULL,"
+					+ " alias _STRING NOT NULL,"
+					+ " state INT NOT NULL,"
+					+ " timestamp BIGINT NOT NULL,"
+					+ " PRIMARY KEY (pendingContactId))"));
+			s.execute(dbTypes.replaceTypes("CREATE TABLE outgoingHandshakeKeys"
+					+ " (transportId _STRING NOT NULL,"
+					+ " keySetId _COUNTER,"
+					+ " timePeriod BIGINT NOT NULL,"
+					+ " contactId INT," // Null if contact is pending
+					+ " pendingContactId _HASH," // Null if not pending
+					+ " rootKey _SECRET NOT NULL,"
+					+ " alice BOOLEAN NOT NULL,"
+					+ " tagKey _SECRET NOT NULL,"
+					+ " headerKey _SECRET NOT NULL,"
+					+ " stream BIGINT NOT NULL,"
+					+ " PRIMARY KEY (transportId, keySetId),"
+					+ " FOREIGN KEY (transportId)"
+					+ " REFERENCES transports (transportId)"
+					+ " ON DELETE CASCADE,"
+					+ " UNIQUE (keySetId),"
+					+ " FOREIGN KEY (contactId)"
+					+ " REFERENCES contacts (contactId)"
+					+ " ON DELETE CASCADE,"
+					+ " FOREIGN KEY (pendingContactId)"
+					+ " REFERENCES pendingContacts (pendingContactId)"
+					+ " ON DELETE CASCADE)"));
+			s.execute(dbTypes.replaceTypes("CREATE TABLE incomingHandshakeKeys"
+					+ " (transportId _STRING NOT NULL,"
+					+ " keySetId INT NOT NULL,"
+					+ " timePeriod BIGINT NOT NULL,"
+					+ " tagKey _SECRET NOT NULL,"
+					+ " headerKey _SECRET NOT NULL,"
+					+ " base BIGINT NOT NULL,"
+					+ " bitmap _BINARY NOT NULL,"
+					+ " periodOffset INT NOT NULL,"
+					+ " PRIMARY KEY (transportId, keySetId, periodOffset),"
+					+ " FOREIGN KEY (transportId)"
+					+ " REFERENCES transports (transportId)"
+					+ " ON DELETE CASCADE,"
+					+ " FOREIGN KEY (keySetId)"
+					+ " REFERENCES outgoingHandshakeKeys (keySetId)"
+					+ " ON DELETE CASCADE)"));
+		} catch (SQLException e) {
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/db/Migration42_43.java

@@ -0,0 +1,52 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.db.DbException;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
+class Migration42_43 implements Migration<Connection> {
+
+	private static final Logger LOG = getLogger(Migration42_43.class.getName());
+
+	private final DatabaseTypes dbTypes;
+
+	Migration42_43(DatabaseTypes dbTypes) {
+		this.dbTypes = dbTypes;
+	}
+
+	@Override
+	public int getStartVersion() {
+		return 42;
+	}
+
+	@Override
+	public int getEndVersion() {
+		return 43;
+	}
+
+	@Override
+	public void migrate(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			s = txn.createStatement();
+			s.execute(dbTypes.replaceTypes("ALTER TABLE localAuthors"
+					+ " ADD COLUMN handshakePublicKey _BINARY"));
+			s.execute(dbTypes.replaceTypes("ALTER TABLE localAuthors"
+					+ " ADD COLUMN handshakePrivateKey _BINARY"));
+			s.execute(dbTypes.replaceTypes("ALTER TABLE contacts"
+					+ " ADD COLUMN handshakePublicKey _BINARY"));
+			s.execute("ALTER TABLE contacts"
+					+ " DROP COLUMN active");
+		} catch (SQLException e) {
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/db/Migration43_44.java

@@ -0,0 +1,40 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.db.DbException;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
+class Migration43_44 implements Migration<Connection> {
+
+	private static final Logger LOG = getLogger(Migration43_44.class.getName());
+
+	@Override
+	public int getStartVersion() {
+		return 43;
+	}
+
+	@Override
+	public int getEndVersion() {
+		return 44;
+	}
+
+	@Override
+	public void migrate(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			s = txn.createStatement();
+			s.execute("ALTER TABLE contacts"
+					+ " DROP COLUMN localAuthorId");
+		} catch (SQLException e) {
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/event/DefaultEventExecutorModule.java

@@ -0,0 +1,32 @@
+package org.briarproject.bramble.event;
+
+import org.briarproject.bramble.api.event.EventExecutor;
+
+import java.util.concurrent.Executor;
+
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+import static java.util.concurrent.Executors.newSingleThreadExecutor;
+
+/**
+ * Default implementation of {@link EventExecutor} that uses a dedicated thread
+ * to notify listeners of events. Applications may prefer to supply an
+ * implementation that uses an existing thread, such as the UI thread.
+ */
+@Module
+public class DefaultEventExecutorModule {
+
+	@Provides
+	@Singleton
+	@EventExecutor
+	Executor provideEventExecutor() {
+		return newSingleThreadExecutor(r -> {
+			Thread t = new Thread(r);
+			t.setDaemon(true);
+			return t;
+		});
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/event/EventBusImpl.java

@@ -2,13 +2,16 @@ package org.briarproject.bramble.event;
 
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.util.Collection;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.Executor;
 
 import javax.annotation.concurrent.ThreadSafe;
+import javax.inject.Inject;
 
 @ThreadSafe
 @NotNullByDefault
@@ -16,6 +19,12 @@ class EventBusImpl implements EventBus {
 
 	private final Collection<EventListener> listeners =
 			new CopyOnWriteArrayList<>();
+	private final Executor eventExecutor;
+
+	@Inject
+	EventBusImpl(@EventExecutor Executor eventExecutor) {
+		this.eventExecutor = eventExecutor;
+	}
 
 	@Override
 	public void addListener(EventListener l) {
@@ -29,6 +38,8 @@ class EventBusImpl implements EventBus {
 
 	@Override
 	public void broadcast(Event e) {
-		for (EventListener l : listeners) l.eventOccurred(e);
+		eventExecutor.execute(() -> {
+			for (EventListener l : listeners) l.eventOccurred(e);
+		});
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/event/EventModule.java

@@ -12,7 +12,7 @@ public class EventModule {
 
 	@Provides
 	@Singleton
-	EventBus provideEventBus() {
-		return new EventBusImpl();
+	EventBus provideEventBus(EventBusImpl eventBus) {
+		return eventBus;
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementProtocol.java

@@ -14,7 +14,7 @@ import java.io.IOException;
 import java.security.GeneralSecurityException;
 import java.util.Arrays;
 
-import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.MASTER_SECRET_LABEL;
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.MASTER_KEY_LABEL;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.SHARED_SECRET_LABEL;
 
@@ -90,7 +90,7 @@ class KeyAgreementProtocol {
 	/**
 	 * Perform the BQP protocol.
 	 *
-	 * @return the negotiated master secret.
+	 * @return the negotiated master key.
 	 * @throws AbortException when the protocol may have been tampered with.
 	 * @throws IOException for all other other connection errors.
 	 */
@@ -115,7 +115,7 @@ class KeyAgreementProtocol {
 				receiveConfirm(s, theirPublicKey);
 				sendConfirm(s, theirPublicKey);
 			}
-			return crypto.deriveKey(MASTER_SECRET_LABEL, s);
+			return crypto.deriveKey(MASTER_KEY_LABEL, s);
 		} catch (AbortException e) {
 			sendAbort(e.getCause() != null);
 			throw e;

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementTaskImpl.java

@@ -114,9 +114,9 @@ class KeyAgreementTaskImpl extends Thread implements KeyAgreementTask,
 				keyAgreementCrypto, payloadEncoder, transport, remotePayload,
 				localPayload, localKeyPair, alice);
 		try {
-			SecretKey master = protocol.perform();
+			SecretKey masterKey = protocol.perform();
 			KeyAgreementResult result =
-					new KeyAgreementResult(master, transport.getConnection(),
+					new KeyAgreementResult(masterKey, transport.getConnection(),
 							transport.getTransportId(), alice);
 			LOG.info("Finished BQP protocol");
 			// Broadcast result to caller

bramble-core/src/main/java/org/briarproject/bramble/plugin/Poller.java

@@ -1,7 +1,7 @@
 package org.briarproject.bramble.plugin;
 
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.event.ContactStatusChangedEvent;
+import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
@@ -80,12 +80,10 @@ class Poller implements EventListener {
 
 	@Override
 	public void eventOccurred(Event e) {
-		if (e instanceof ContactStatusChangedEvent) {
-			ContactStatusChangedEvent c = (ContactStatusChangedEvent) e;
-			if (c.isActive()) {
-				// Connect to the newly activated contact
-				connectToContact(c.getContactId());
-			}
+		if (e instanceof ContactAddedEvent) {
+			ContactAddedEvent c = (ContactAddedEvent) e;
+			// Connect to the newly activated contact
+			connectToContact(c.getContactId());
 		} else if (e instanceof ConnectionClosedEvent) {
 			ConnectionClosedEvent c = (ConnectionClosedEvent) e;
 			// Reschedule polling, the polling interval may have decreased

bramble-core/src/main/java/org/briarproject/bramble/properties/TransportPropertyManagerImpl.java

@@ -13,6 +13,8 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.identity.AuthorId;
+import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
@@ -44,6 +46,7 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 
 	private final DatabaseComponent db;
 	private final ClientHelper clientHelper;
+	private final IdentityManager identityManager;
 	private final ClientVersioningManager clientVersioningManager;
 	private final MetadataParser metadataParser;
 	private final ContactGroupFactory contactGroupFactory;
@@ -53,11 +56,13 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	@Inject
 	TransportPropertyManagerImpl(DatabaseComponent db,
 			ClientHelper clientHelper,
+			IdentityManager identityManager,
 			ClientVersioningManager clientVersioningManager,
 			MetadataParser metadataParser,
 			ContactGroupFactory contactGroupFactory, Clock clock) {
 		this.db = db;
 		this.clientHelper = clientHelper;
+		this.identityManager = identityManager;
 		this.clientVersioningManager = clientVersioningManager;
 		this.metadataParser = metadataParser;
 		this.contactGroupFactory = contactGroupFactory;
@@ -77,7 +82,7 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	@Override
 	public void addingContact(Transaction txn, Contact c) throws DbException {
 		// Create a group to share with the contact
-		Group g = getContactGroup(c);
+		Group g = getContactGroup(c, getLocalAuthorId(txn));
 		db.addGroup(txn, g);
 		// Apply the client's visibility to the contact group
 		Visibility client = clientVersioningManager.getClientVisibility(txn,
@@ -93,14 +98,14 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 
 	@Override
 	public void removingContact(Transaction txn, Contact c) throws DbException {
-		db.removeGroup(txn, getContactGroup(c));
+		db.removeGroup(txn, getContactGroup(c, getLocalAuthorId(txn)));
 	}
 
 	@Override
 	public void onClientVisibilityChanging(Transaction txn, Contact c,
 			Visibility v) throws DbException {
 		// Apply the client's visibility to the contact group
-		Group g = getContactGroup(c);
+		Group g = getContactGroup(c, getLocalAuthorId(txn));
 		db.setGroupVisibility(txn, c.getId(), g.getId(), v);
 	}
 
@@ -132,7 +137,7 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	@Override
 	public void addRemoteProperties(Transaction txn, ContactId c,
 			Map<TransportId, TransportProperties> props) throws DbException {
-		Group g = getContactGroup(db.getContact(txn, c));
+		Group g = getContactGroup(db.getContact(txn, c), getLocalAuthorId(txn));
 		for (Entry<TransportId, TransportProperties> e : props.entrySet()) {
 			storeMessage(txn, g.getId(), e.getKey(), e.getValue(), 0,
 					false, false);
@@ -191,17 +196,16 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 			TransportId t) throws DbException {
 		return db.transactionWithResult(true, txn -> {
 			Map<ContactId, TransportProperties> remote = new HashMap<>();
+			AuthorId local = getLocalAuthorId(txn);
 			for (Contact c : db.getContacts(txn))
-				remote.put(c.getId(), getRemoteProperties(txn, c, t));
+				remote.put(c.getId(), getRemoteProperties(txn, c, local, t));
 			return remote;
 		});
 	}
 
 	private TransportProperties getRemoteProperties(Transaction txn, Contact c,
-			TransportId t) throws DbException {
-		// Don't return properties for inactive contacts
-		if (!c.isActive()) return new TransportProperties();
-		Group g = getContactGroup(c);
+			AuthorId local, TransportId t) throws DbException {
+		Group g = getContactGroup(c, local);
 		try {
 			// Find the latest remote update
 			LatestUpdate latest = findLatest(txn, g.getId(), t, false);
@@ -218,8 +222,11 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	@Override
 	public TransportProperties getRemoteProperties(ContactId c, TransportId t)
 			throws DbException {
-		return db.transactionWithResult(true, txn ->
-				getRemoteProperties(txn, db.getContact(txn, c), t));
+		return db.transactionWithResult(true, txn -> {
+			Contact contact = db.getContact(txn ,c);
+			AuthorId local = getLocalAuthorId(txn);
+			return getRemoteProperties(txn, contact, local, t);
+		});
 	}
 
 	@Override
@@ -252,8 +259,9 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 					if (latest != null)
 						db.removeMessage(txn, latest.messageId);
 					// Store the merged properties in each contact's group
+					AuthorId localAuthorId = getLocalAuthorId(txn);
 					for (Contact c : db.getContacts(txn)) {
-						Group g = getContactGroup(c);
+						Group g = getContactGroup(c, localAuthorId);
 						latest = findLatest(txn, g.getId(), t, true);
 						version = latest == null ? 1 : latest.version + 1;
 						storeMessage(txn, g.getId(), t, merged, version,
@@ -269,9 +277,13 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		}
 	}
 
-	private Group getContactGroup(Contact c) {
+	private AuthorId getLocalAuthorId(Transaction txn) throws DbException {
+		return identityManager.getLocalAuthor(txn).getId();
+	}
+
+	private Group getContactGroup(Contact c, AuthorId local) {
 		return contactGroupFactory.createContactGroup(CLIENT_ID,
-				MAJOR_VERSION, c);
+				MAJOR_VERSION, c, local);
 	}
 
 	private void storeMessage(Transaction txn, GroupId g, TransportId t,

bramble-core/src/main/java/org/briarproject/bramble/transport/KeyManagerImpl.java

@@ -1,9 +1,7 @@
 package org.briarproject.bramble.transport;
 
-import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
-import org.briarproject.bramble.api.contact.event.ContactStatusChangedEvent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
@@ -19,8 +17,8 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -46,7 +44,6 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 	private final Executor dbExecutor;
 	private final PluginConfig pluginConfig;
 	private final TransportKeyManagerFactory transportKeyManagerFactory;
-	private final Map<ContactId, Boolean> activeContacts;
 	private final ConcurrentHashMap<TransportId, TransportKeyManager> managers;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
@@ -58,8 +55,6 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 		this.dbExecutor = dbExecutor;
 		this.pluginConfig = pluginConfig;
 		this.transportKeyManagerFactory = transportKeyManagerFactory;
-		// Use a ConcurrentHashMap as a thread-safe set
-		activeContacts = new ConcurrentHashMap<>();
 		managers = new ConcurrentHashMap<>();
 	}
 
@@ -73,8 +68,6 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 			transports.put(f.getId(), f.getMaxLatency());
 		try {
 			db.transaction(false, txn -> {
-				for (Contact c : db.getContacts(txn))
-					if (c.isActive()) activeContacts.put(c.getId(), true);
 				for (Entry<TransportId, Integer> e : transports.entrySet())
 					db.addTransport(txn, e.getKey(), e.getValue());
 				for (Entry<TransportId, Integer> e : transports.entrySet()) {
@@ -95,22 +88,22 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 	}
 
 	@Override
-	public Map<TransportId, KeySetId> addContact(Transaction txn, ContactId c,
-			SecretKey master, long timestamp, boolean alice, boolean active)
-			throws DbException {
-		Map<TransportId, KeySetId> ids = new HashMap<>();
+	public Map<TransportId, TransportKeySetId> addContact(Transaction txn,
+			ContactId c, SecretKey rootKey, long timestamp, boolean alice,
+			boolean active) throws DbException {
+		Map<TransportId, TransportKeySetId> ids = new HashMap<>();
 		for (Entry<TransportId, TransportKeyManager> e : managers.entrySet()) {
 			TransportId t = e.getKey();
 			TransportKeyManager m = e.getValue();
-			ids.put(t, m.addContact(txn, c, master, timestamp, alice, active));
+			ids.put(t, m.addContact(txn, c, rootKey, timestamp, alice, active));
 		}
 		return ids;
 	}
 
 	@Override
-	public void activateKeys(Transaction txn, Map<TransportId, KeySetId> keys)
-			throws DbException {
-		for (Entry<TransportId, KeySetId> e : keys.entrySet()) {
+	public void activateKeys(Transaction txn, Map<TransportId,
+			TransportKeySetId> keys) throws DbException {
+		for (Entry<TransportId, TransportKeySetId> e : keys.entrySet()) {
 			TransportId t = e.getKey();
 			TransportKeyManager m = managers.get(t);
 			if (m == null) {
@@ -130,8 +123,6 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 	@Override
 	public StreamContext getStreamContext(ContactId c, TransportId t)
 			throws DbException {
-		// Don't allow outgoing streams to inactive contacts
-		if (!activeContacts.containsKey(c)) return null;
 		TransportKeyManager m = managers.get(t);
 		if (m == null) {
 			if (LOG.isLoggable(INFO)) LOG.info("No key manager for " + t);
@@ -157,15 +148,10 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 	public void eventOccurred(Event e) {
 		if (e instanceof ContactRemovedEvent) {
 			removeContact(((ContactRemovedEvent) e).getContactId());
-		} else if (e instanceof ContactStatusChangedEvent) {
-			ContactStatusChangedEvent c = (ContactStatusChangedEvent) e;
-			if (c.isActive()) activeContacts.put(c.getContactId(), true);
-			else activeContacts.remove(c.getContactId());
 		}
 	}
 
 	private void removeContact(ContactId c) {
-		activeContacts.remove(c);
 		dbExecutor.execute(() -> {
 			for (TransportKeyManager m : managers.values()) m.removeContact(c);
 		});

bramble-core/src/main/java/org/briarproject/bramble/transport/MutableIncomingKeys.java

@@ -11,18 +11,18 @@ import javax.annotation.concurrent.NotThreadSafe;
 class MutableIncomingKeys {
 
 	private final SecretKey tagKey, headerKey;
-	private final long rotationPeriod;
+	private final long timePeriod;
 	private final ReorderingWindow window;
 
 	MutableIncomingKeys(IncomingKeys in) {
 		tagKey = in.getTagKey();
 		headerKey = in.getHeaderKey();
-		rotationPeriod = in.getRotationPeriod();
+		timePeriod = in.getTimePeriod();
 		window = new ReorderingWindow(in.getWindowBase(), in.getWindowBitmap());
 	}
 
 	IncomingKeys snapshot() {
-		return new IncomingKeys(tagKey, headerKey, rotationPeriod,
+		return new IncomingKeys(tagKey, headerKey, timePeriod,
 				window.getBase(), window.getBitmap());
 	}
 
@@ -34,8 +34,8 @@ class MutableIncomingKeys {
 		return headerKey;
 	}
 
-	long getRotationPeriod() {
-		return rotationPeriod;
+	long getTimePeriod() {
+		return timePeriod;
 	}
 
 	ReorderingWindow getWindow() {

bramble-core/src/main/java/org/briarproject/bramble/transport/MutableKeySet.java

@@ -1,22 +1,22 @@
 package org.briarproject.bramble.transport;
 
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 
 class MutableKeySet {
 
-	private final KeySetId keySetId;
+	private final TransportKeySetId keySetId;
 	private final ContactId contactId;
 	private final MutableTransportKeys transportKeys;
 
-	MutableKeySet(KeySetId keySetId, ContactId contactId,
+	MutableKeySet(TransportKeySetId keySetId, ContactId contactId,
 			MutableTransportKeys transportKeys) {
 		this.keySetId = keySetId;
 		this.contactId = contactId;
 		this.transportKeys = transportKeys;
 	}
 
-	KeySetId getKeySetId() {
+	TransportKeySetId getKeySetId() {
 		return keySetId;
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/transport/MutableOutgoingKeys.java

@@ -11,20 +11,20 @@ import javax.annotation.concurrent.NotThreadSafe;
 class MutableOutgoingKeys {
 
 	private final SecretKey tagKey, headerKey;
-	private final long rotationPeriod;
+	private final long timePeriod;
 	private long streamCounter;
 	private boolean active;
 
 	MutableOutgoingKeys(OutgoingKeys out) {
 		tagKey = out.getTagKey();
 		headerKey = out.getHeaderKey();
-		rotationPeriod = out.getRotationPeriod();
+		timePeriod = out.getTimePeriod();
 		streamCounter = out.getStreamCounter();
 		active = out.isActive();
 	}
 
 	OutgoingKeys snapshot() {
-		return new OutgoingKeys(tagKey, headerKey, rotationPeriod,
+		return new OutgoingKeys(tagKey, headerKey, timePeriod,
 				streamCounter, active);
 	}
 
@@ -36,8 +36,8 @@ class MutableOutgoingKeys {
 		return headerKey;
 	}
 
-	long getRotationPeriod() {
-		return rotationPeriod;
+	long getTimePeriod() {
+		return timePeriod;
 	}
 
 	long getStreamCounter() {

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManager.java

@@ -5,8 +5,8 @@ import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 
 import javax.annotation.Nullable;
 
@@ -15,10 +15,11 @@ interface TransportKeyManager {
 
 	void start(Transaction txn) throws DbException;
 
-	KeySetId addContact(Transaction txn, ContactId c, SecretKey master,
-			long timestamp, boolean alice, boolean active) throws DbException;
+	TransportKeySetId addContact(Transaction txn, ContactId c,
+			SecretKey rootKey, long timestamp, boolean alice, boolean active)
+			throws DbException;
 
-	void activateKeys(Transaction txn, KeySetId k) throws DbException;
+	void activateKeys(Transaction txn, TransportKeySetId k) throws DbException;
 
 	void removeContact(ContactId c);
 

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManagerImpl.java

@@ -11,9 +11,9 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.Scheduler;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.transport.ReorderingWindow.Change;
 
@@ -51,12 +51,12 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	private final ScheduledExecutorService scheduler;
 	private final Clock clock;
 	private final TransportId transportId;
-	private final long rotationPeriodLength;
+	private final long timePeriodLength;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 	private final ReentrantLock lock = new ReentrantLock();
 
 	// The following are locking: lock
-	private final Map<KeySetId, MutableKeySet> keys = new HashMap<>();
+	private final Map<TransportKeySetId, MutableKeySet> keys = new HashMap<>();
 	private final Map<Bytes, TagContext> inContexts = new HashMap<>();
 	private final Map<ContactId, MutableKeySet> outContexts = new HashMap<>();
 
@@ -70,7 +70,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		this.scheduler = scheduler;
 		this.clock = clock;
 		this.transportId = transportId;
-		rotationPeriodLength = maxLatency + MAX_CLOCK_DIFFERENCE;
+		timePeriodLength = maxLatency + MAX_CLOCK_DIFFERENCE;
 	}
 
 	@Override
@@ -80,8 +80,9 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		lock.lock();
 		try {
 			// Load the transport keys from the DB
-			Collection<KeySet> loaded = db.getTransportKeys(txn, transportId);
-			// Rotate the keys to the current rotation period
+			Collection<TransportKeySet> loaded =
+					db.getTransportKeys(txn, transportId);
+			// Rotate the keys to the current time period
 			RotationResult rotationResult = rotateKeys(loaded, now);
 			// Initialise mutable state for all contacts
 			addKeys(rotationResult.current);
@@ -95,15 +96,17 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		scheduleKeyRotation(now);
 	}
 
-	private RotationResult rotateKeys(Collection<KeySet> keys, long now) {
+	private RotationResult rotateKeys(Collection<TransportKeySet> keys,
+			long now) {
 		RotationResult rotationResult = new RotationResult();
-		long rotationPeriod = now / rotationPeriodLength;
-		for (KeySet ks : keys) {
-			TransportKeys k = ks.getTransportKeys();
-			TransportKeys k1 =
-					transportCrypto.rotateTransportKeys(k, rotationPeriod);
-			KeySet ks1 = new KeySet(ks.getKeySetId(), ks.getContactId(), k1);
-			if (k1.getRotationPeriod() > k.getRotationPeriod())
+		long timePeriod = now / timePeriodLength;
+		for (TransportKeySet ks : keys) {
+			TransportKeys k = ks.getKeys();
+			TransportKeys k1 = transportCrypto.rotateTransportKeys(k,
+					timePeriod);
+			TransportKeySet ks1 = new TransportKeySet(ks.getKeySetId(),
+					ks.getContactId(), k1);
+			if (k1.getTimePeriod() > k.getTimePeriod())
 				rotationResult.rotated.add(ks1);
 			rotationResult.current.add(ks1);
 		}
@@ -111,15 +114,15 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	// Locking: lock
-	private void addKeys(Collection<KeySet> keys) {
-		for (KeySet ks : keys) {
+	private void addKeys(Collection<TransportKeySet> keys) {
+		for (TransportKeySet ks : keys) {
 			addKeys(ks.getKeySetId(), ks.getContactId(),
-					new MutableTransportKeys(ks.getTransportKeys()));
+					new MutableTransportKeys(ks.getKeys()));
 		}
 	}
 
 	// Locking: lock
-	private void addKeys(KeySetId keySetId, ContactId contactId,
+	private void addKeys(TransportKeySetId keySetId, ContactId contactId,
 			MutableTransportKeys m) {
 		MutableKeySet ks = new MutableKeySet(keySetId, contactId, m);
 		keys.put(keySetId, ks);
@@ -130,7 +133,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	// Locking: lock
-	private void encodeTags(KeySetId keySetId, ContactId contactId,
+	private void encodeTags(TransportKeySetId keySetId, ContactId contactId,
 			MutableIncomingKeys inKeys) {
 		for (long streamNumber : inKeys.getWindow().getUnseen()) {
 			TagContext tagCtx =
@@ -155,7 +158,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	private void scheduleKeyRotation(long now) {
-		long delay = rotationPeriodLength - now % rotationPeriodLength;
+		long delay = timePeriodLength - now % timePeriodLength;
 		scheduler.schedule((Runnable) this::rotateKeys, delay, MILLISECONDS);
 	}
 
@@ -170,20 +173,21 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	@Override
-	public KeySetId addContact(Transaction txn, ContactId c, SecretKey master,
-			long timestamp, boolean alice, boolean active) throws DbException {
+	public TransportKeySetId addContact(Transaction txn, ContactId c,
+			SecretKey rootKey, long timestamp, boolean alice, boolean active)
+			throws DbException {
 		lock.lock();
 		try {
-			// Work out what rotation period the timestamp belongs to
-			long rotationPeriod = timestamp / rotationPeriodLength;
+			// Work out what time period the timestamp belongs to
+			long timePeriod = timestamp / timePeriodLength;
 			// Derive the transport keys
 			TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
-					master, rotationPeriod, alice, active);
-			// Rotate the keys to the current rotation period if necessary
-			rotationPeriod = clock.currentTimeMillis() / rotationPeriodLength;
-			k = transportCrypto.rotateTransportKeys(k, rotationPeriod);
+					rootKey, timePeriod, alice, active);
+			// Rotate the keys to the current time period if necessary
+			timePeriod = clock.currentTimeMillis() / timePeriodLength;
+			k = transportCrypto.rotateTransportKeys(k, timePeriod);
 			// Write the keys back to the DB
-			KeySetId keySetId = db.addTransportKeys(txn, c, k);
+			TransportKeySetId keySetId = db.addTransportKeys(txn, c, k);
 			// Initialise mutable state for the contact
 			addKeys(keySetId, c, new MutableTransportKeys(k));
 			return keySetId;
@@ -193,7 +197,8 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	@Override
-	public void activateKeys(Transaction txn, KeySetId k) throws DbException {
+	public void activateKeys(Transaction txn, TransportKeySetId k)
+			throws DbException {
 		lock.lock();
 		try {
 			MutableKeySet ks = keys.get(k);
@@ -300,7 +305,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 			}
 			// Write the window back to the DB
 			db.setReorderingWindow(txn, tagCtx.keySetId, transportId,
-					inKeys.getRotationPeriod(), window.getBase(),
+					inKeys.getTimePeriod(), window.getBase(),
 					window.getBitmap());
 			// If the outgoing keys are inactive, activate them
 			MutableKeySet ks = keys.get(tagCtx.keySetId);
@@ -322,11 +327,11 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		long now = clock.currentTimeMillis();
 		lock.lock();
 		try {
-			// Rotate the keys to the current rotation period
-			Collection<KeySet> snapshot = new ArrayList<>(keys.size());
+			// Rotate the keys to the current time period
+			Collection<TransportKeySet> snapshot = new ArrayList<>(keys.size());
 			for (MutableKeySet ks : keys.values()) {
-				snapshot.add(new KeySet(ks.getKeySetId(), ks.getContactId(),
-						ks.getTransportKeys().snapshot()));
+				snapshot.add(new TransportKeySet(ks.getKeySetId(),
+						ks.getContactId(), ks.getTransportKeys().snapshot()));
 			}
 			RotationResult rotationResult = rotateKeys(snapshot, now);
 			// Rebuild the mutable state for all contacts
@@ -346,12 +351,12 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 
 	private static class TagContext {
 
-		private final KeySetId keySetId;
+		private final TransportKeySetId keySetId;
 		private final ContactId contactId;
 		private final MutableIncomingKeys inKeys;
 		private final long streamNumber;
 
-		private TagContext(KeySetId keySetId, ContactId contactId,
+		private TagContext(TransportKeySetId keySetId, ContactId contactId,
 				MutableIncomingKeys inKeys, long streamNumber) {
 			this.keySetId = keySetId;
 			this.contactId = contactId;
@@ -362,7 +367,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 
 	private static class RotationResult {
 
-		private final Collection<KeySet> current = new ArrayList<>();
-		private final Collection<KeySet> rotated = new ArrayList<>();
+		private final Collection<TransportKeySet> current = new ArrayList<>();
+		private final Collection<TransportKeySet> rotated = new ArrayList<>();
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/versioning/ClientVersioningManagerImpl.java

@@ -12,6 +12,8 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.identity.AuthorId;
+import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.lifecycle.ServiceException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -58,6 +60,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 
 	private final DatabaseComponent db;
 	private final ClientHelper clientHelper;
+	private final IdentityManager identityManager;
 	private final ContactGroupFactory contactGroupFactory;
 	private final Clock clock;
 	private final Group localGroup;
@@ -68,9 +71,11 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 
 	@Inject
 	ClientVersioningManagerImpl(DatabaseComponent db, ClientHelper clientHelper,
+			IdentityManager identityManager,
 			ContactGroupFactory contactGroupFactory, Clock clock) {
 		this.db = db;
 		this.clientHelper = clientHelper;
+		this.identityManager = identityManager;
 		this.contactGroupFactory = contactGroupFactory;
 		this.clock = clock;
 		localGroup = contactGroupFactory.createLocalGroup(CLIENT_ID,
@@ -154,7 +159,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 	@Override
 	public void addingContact(Transaction txn, Contact c) throws DbException {
 		// Create a group and share it with the contact
-		Group g = getContactGroup(c);
+		Group g = getContactGroup(c, getLocalAuthorId(txn));
 		db.addGroup(txn, g);
 		db.setGroupVisibility(txn, c.getId(), g.getId(), SHARED);
 		// Attach the contact ID to the group
@@ -173,7 +178,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 
 	@Override
 	public void removingContact(Transaction txn, Contact c) throws DbException {
-		db.removeGroup(txn, getContactGroup(c));
+		db.removeGroup(txn, getContactGroup(c, getLocalAuthorId(txn)));
 	}
 
 	@Override
@@ -308,7 +313,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 			List<ClientVersion> versions) throws DbException {
 		try {
 			// Find the latest local and remote updates
-			Group g = getContactGroup(c);
+			Group g = getContactGroup(c, getLocalAuthorId(txn));
 			LatestUpdates latest = findLatestUpdates(txn, g.getId());
 			// Load and parse the latest local update
 			if (latest.local == null) throw new DbException();
@@ -344,16 +349,20 @@ class ClientVersioningManagerImpl implements ClientVersioningManager, Client,
 		}
 	}
 
-	private Group getContactGroup(Contact c) {
+	private AuthorId getLocalAuthorId(Transaction txn) throws DbException {
+		return identityManager.getLocalAuthor(txn).getId();
+	}
+
+	private Group getContactGroup(Contact c, AuthorId local) {
 		return contactGroupFactory.createContactGroup(CLIENT_ID,
-				MAJOR_VERSION, c);
+				MAJOR_VERSION, c, local);
 	}
 
 	@Nullable
 	private LatestUpdates findLatestUpdates(Transaction txn, ContactId c)
 			throws DbException, FormatException {
 		Contact contact = db.getContact(txn, c);
-		Group g = getContactGroup(contact);
+		Group g = getContactGroup(contact, getLocalAuthorId(txn));
 		// Contact may be in the process of being added or removed, so
 		// contact group may not exist
 		if (!db.containsGroup(txn, g.getId())) return null;

bramble-core/src/test/java/org/briarproject/bramble/contact/ContactManagerImplTest.java

@@ -5,27 +5,20 @@ import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseComponent;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.NoSuchContactException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.transport.KeyManager;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.DbExpectations;
-import org.jmock.Expectations;
 import org.jmock.Mockery;
 import org.junit.Test;
 
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Random;
 
-import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.OURSELVES;
@@ -33,8 +26,8 @@ import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNKNOWN;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNVERIFIED;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.VERIFIED;
 import static org.briarproject.bramble.test.TestUtils.getAuthor;
+import static org.briarproject.bramble.test.TestUtils.getContact;
 import static org.briarproject.bramble.test.TestUtils.getLocalAuthor;
-import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.junit.Assert.assertEquals;
@@ -49,42 +42,40 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 	private final IdentityManager identityManager =
 			context.mock(IdentityManager.class);
 	private final ContactManager contactManager;
-	private final ContactId contactId = new ContactId(42);
-	private final Author remote = getAuthor();
-	private final AuthorId local = new AuthorId(getRandomId());
+	private final Author author = getAuthor();
 	private final LocalAuthor localAuthor = getLocalAuthor();
-	private final String alias = getRandomString(MAX_AUTHOR_NAME_LENGTH);
 	private final boolean verified = false, active = true;
-	private final Contact contact =
-			new Contact(contactId, remote, local, alias, verified, active);
+	private final Contact contact = getContact(author, verified);
+	private final ContactId contactId = contact.getId();
 
 	public ContactManagerImplTest() {
-		contactManager = new ContactManagerImpl(db, keyManager, identityManager);
+		contactManager =
+				new ContactManagerImpl(db, keyManager, identityManager);
 	}
 
 	@Test
 	public void testAddContact() throws Exception {
-		SecretKey master = getSecretKey();
+		SecretKey rootKey = getSecretKey();
 		long timestamp = System.currentTimeMillis();
 		boolean alice = new Random().nextBoolean();
 		Transaction txn = new Transaction(null, false);
 
 		context.checking(new DbExpectations() {{
 			oneOf(db).transactionWithResult(with(false), withDbCallable(txn));
-			oneOf(db).addContact(txn, remote, local, verified, active);
+			oneOf(db).addContact(txn, author, verified);
 			will(returnValue(contactId));
-			oneOf(keyManager).addContact(txn, contactId, master, timestamp,
+			oneOf(keyManager).addContact(txn, contactId, rootKey, timestamp,
 					alice, active);
 			oneOf(db).getContact(txn, contactId);
 			will(returnValue(contact));
 		}});
 
-		assertEquals(contactId, contactManager.addContact(remote, local,
-				master, timestamp, alice, verified, active));
+		assertEquals(contactId, contactManager.addContact(author, rootKey,
+				timestamp, alice, verified, active));
 	}
 
 	@Test
-	public void testGetContact() throws Exception {
+	public void testGetContactByContactId() throws Exception {
 		Transaction txn = new Transaction(null, true);
 		context.checking(new DbExpectations() {{
 			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
@@ -96,49 +87,20 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testGetContactByAuthor() throws Exception {
-		Transaction txn = new Transaction(null, true);
-		Collection<Contact> contacts = Collections.singleton(contact);
-		context.checking(new DbExpectations() {{
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getContactsByAuthorId(txn, remote.getId());
-			will(returnValue(contacts));
-		}});
-
-		assertEquals(contact, contactManager.getContact(remote.getId(), local));
-	}
-
-	@Test(expected = NoSuchContactException.class)
-	public void testGetContactByUnknownAuthor() throws Exception {
+	public void testGetContactByAuthorId() throws Exception {
 		Transaction txn = new Transaction(null, true);
 		context.checking(new DbExpectations() {{
 			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getContactsByAuthorId(txn, remote.getId());
-			will(returnValue(emptyList()));
+			oneOf(db).getContact(txn, author.getId());
+			will(returnValue(contact));
 		}});
 
-		contactManager.getContact(remote.getId(), local);
-	}
-
-	@Test(expected = NoSuchContactException.class)
-	public void testGetContactByUnknownLocalAuthor() throws Exception {
-		Transaction txn = new Transaction(null, true);
-		Collection<Contact> contacts = Collections.singleton(contact);
-		context.checking(new DbExpectations() {{
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getContactsByAuthorId(txn, remote.getId());
-			will(returnValue(contacts));
-		}});
-
-		contactManager.getContact(remote.getId(), new AuthorId(getRandomId()));
+		assertEquals(contact, contactManager.getContact(author.getId()));
 	}
 
 	@Test
-	public void testGetActiveContacts() throws Exception {
-		Collection<Contact> activeContacts = Collections.singletonList(contact);
-		Collection<Contact> contacts = new ArrayList<>(activeContacts);
-		contacts.add(new Contact(new ContactId(3), remote, local, alias, true,
-				false));
+	public void testGetContacts() throws Exception {
+		Collection<Contact> contacts = singletonList(contact);
 		Transaction txn = new Transaction(null, true);
 		context.checking(new DbExpectations() {{
 			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
@@ -146,7 +108,7 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(contacts));
 		}});
 
-		assertEquals(activeContacts, contactManager.getActiveContacts());
+		assertEquals(contacts, contactManager.getContacts());
 	}
 
 	@Test
@@ -162,19 +124,11 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 		contactManager.removeContact(contactId);
 	}
 
-	@Test
-	public void testSetContactActive() throws Exception {
-		Transaction txn = new Transaction(null, false);
-		context.checking(new Expectations() {{
-			oneOf(db).setContactActive(txn, contactId, active);
-		}});
-
-		contactManager.setContactActive(txn, contactId, active);
-	}
-
 	@Test
 	public void testSetContactAlias() throws Exception {
 		Transaction txn = new Transaction(null, false);
+		String alias = getRandomString(MAX_AUTHOR_NAME_LENGTH);
+
 		context.checking(new DbExpectations() {{
 			oneOf(db).transaction(with(false), withDbRunnable(txn));
 			oneOf(db).setContactAlias(txn, contactId, alias);
@@ -195,85 +149,82 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 		Transaction txn = new Transaction(null, true);
 		context.checking(new DbExpectations() {{
 			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).containsContact(txn, remote.getId(), local);
+			oneOf(db).containsContact(txn, author.getId());
 			will(returnValue(true));
 		}});
 
-		assertTrue(contactManager.contactExists(remote.getId(), local));
+		assertTrue(contactManager.contactExists(author.getId()));
 	}
 
 	@Test
-	public void testGetAuthorInfo() throws Exception {
+	public void testGetAuthorInfoOurselves() throws Exception {
 		Transaction txn = new Transaction(null, true);
-		Collection<Contact> contacts = singletonList(
-				new Contact(new ContactId(1), remote, localAuthor.getId(),
-						alias, false, true));
 
 		context.checking(new DbExpectations() {{
 			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
 			oneOf(identityManager).getLocalAuthor(txn);
 			will(returnValue(localAuthor));
-			oneOf(db).getContactsByAuthorId(txn, remote.getId());
-			will(returnValue(contacts));
 		}});
 		AuthorInfo authorInfo =
-				contactManager.getAuthorInfo(txn, remote.getId());
-		assertEquals(UNVERIFIED, authorInfo.getStatus());
-		assertEquals(alias, contact.getAlias());
-	}
-
-	@Test
-	public void testGetAuthorInfoTransaction() throws DbException {
-		Transaction txn = new Transaction(null, true);
-
-		// check unknown author
-		context.checking(new Expectations() {{
-			oneOf(identityManager).getLocalAuthor(txn);
-			will(returnValue(localAuthor));
-			oneOf(db).getContactsByAuthorId(txn, remote.getId());
-			will(returnValue(emptyList()));
-		}});
-		AuthorInfo authorInfo =
-				contactManager.getAuthorInfo(txn, remote.getId());
-		assertEquals(UNKNOWN, authorInfo.getStatus());
-		assertNull(authorInfo.getAlias());
-
-		// check unverified contact
-		Collection<Contact> contacts = singletonList(
-				new Contact(new ContactId(1), remote, localAuthor.getId(),
-						alias, false, true));
-		checkAuthorInfoContext(txn, remote.getId(), contacts);
-		authorInfo = contactManager.getAuthorInfo(txn, remote.getId());
-		assertEquals(UNVERIFIED, authorInfo.getStatus());
-		assertEquals(alias, contact.getAlias());
-
-		// check verified contact
-		contacts = singletonList(new Contact(new ContactId(1), remote,
-				localAuthor.getId(), alias, true, true));
-		checkAuthorInfoContext(txn, remote.getId(), contacts);
-		authorInfo = contactManager.getAuthorInfo(txn, remote.getId());
-		assertEquals(VERIFIED, authorInfo.getStatus());
-		assertEquals(alias, contact.getAlias());
-
-		// check ourselves
-		context.checking(new Expectations() {{
-			oneOf(identityManager).getLocalAuthor(txn);
-			will(returnValue(localAuthor));
-			never(db).getContactsByAuthorId(txn, remote.getId());
-		}});
-		authorInfo = contactManager.getAuthorInfo(txn, localAuthor.getId());
+				contactManager.getAuthorInfo(txn, localAuthor.getId());
 		assertEquals(OURSELVES, authorInfo.getStatus());
 		assertNull(authorInfo.getAlias());
 	}
 
-	private void checkAuthorInfoContext(Transaction txn, AuthorId authorId,
-			Collection<Contact> contacts) throws DbException {
-		context.checking(new Expectations() {{
+	@Test
+	public void testGetAuthorInfoVerified() throws Exception {
+		Transaction txn = new Transaction(null, true);
+		Contact verified = getContact(author, true);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
 			oneOf(identityManager).getLocalAuthor(txn);
 			will(returnValue(localAuthor));
-			oneOf(db).getContactsByAuthorId(txn, authorId);
-			will(returnValue(contacts));
+			oneOf(db).containsContact(txn, author.getId());
+			will(returnValue(true));
+			oneOf(db).getContact(txn, author.getId());
+			will(returnValue(verified));
 		}});
+		AuthorInfo authorInfo =
+				contactManager.getAuthorInfo(txn, author.getId());
+		assertEquals(VERIFIED, authorInfo.getStatus());
+		assertEquals(verified.getAlias(), authorInfo.getAlias());
 	}
 
+	@Test
+	public void testGetAuthorInfoUnverified() throws Exception {
+		Transaction txn = new Transaction(null, true);
+		Contact unverified = getContact(author, false);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
+			oneOf(db).containsContact(txn, author.getId());
+			will(returnValue(true));
+			oneOf(db).getContact(txn, author.getId());
+			will(returnValue(unverified));
+		}});
+		AuthorInfo authorInfo =
+				contactManager.getAuthorInfo(txn, author.getId());
+		assertEquals(UNVERIFIED, authorInfo.getStatus());
+		assertEquals(unverified.getAlias(), authorInfo.getAlias());
+	}
+
+	@Test
+	public void testGetAuthorInfoUnknown() throws Exception {
+		Transaction txn = new Transaction(null, true);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
+			oneOf(db).containsContact(txn, author.getId());
+			will(returnValue(false));
+		}});
+		AuthorInfo authorInfo =
+				contactManager.getAuthorInfo(txn, author.getId());
+		assertEquals(UNKNOWN, authorInfo.getStatus());
+		assertNull(authorInfo.getAlias());
+	}
 }

bramble-core/src/test/java/org/briarproject/bramble/crypto/HandshakeKeyDerivationTest.java

@@ -0,0 +1,167 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.crypto.TransportCrypto;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.briarproject.bramble.crypto.KeyDerivationTestUtils.assertAllDifferent;
+import static org.briarproject.bramble.crypto.KeyDerivationTestUtils.assertMatches;
+import static org.briarproject.bramble.test.TestUtils.getSecretKey;
+import static org.briarproject.bramble.test.TestUtils.getTransportId;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertSame;
+
+public class HandshakeKeyDerivationTest extends BrambleTestCase {
+
+	private final CryptoComponent crypto =
+			new CryptoComponentImpl(new TestSecureRandomProvider(), null);
+	private final TransportCrypto transportCrypto =
+			new TransportCryptoImpl(crypto);
+	private final TransportId transportId = getTransportId();
+	private final SecretKey rootKey = getSecretKey();
+
+	@Test
+	public void testKeysAreDistinct() {
+		HandshakeKeys kA = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys kB = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, false);
+		assertAllDifferent(kA);
+		assertAllDifferent(kB);
+	}
+
+	@Test
+	public void testKeysAreNotUpdatedToPreviousPeriod() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 122);
+		assertSame(k, k1);
+	}
+
+	@Test
+	public void testKeysAreNotUpdatedToCurrentPeriod() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 123);
+		assertSame(k, k1);
+	}
+
+	@Test
+	public void testKeysAreUpdatedByOnePeriod() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 124);
+		assertSame(k.getCurrentIncomingKeys(), k1.getPreviousIncomingKeys());
+		assertSame(k.getNextIncomingKeys(), k1.getCurrentIncomingKeys());
+	}
+
+	@Test
+	public void testKeysAreUpdatedByTwoPeriods() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 125);
+		assertSame(k.getNextIncomingKeys(), k1.getPreviousIncomingKeys());
+	}
+
+	@Test
+	public void testKeysAreUpdatedByThreePeriods() {
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.updateHandshakeKeys(k, 126);
+		assertAllDifferent(k, k1);
+	}
+
+	@Test
+	public void testCurrentKeysMatchContact() {
+		// Start in time period 123
+		HandshakeKeys kA = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys kB = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, false);
+		// Alice's incoming keys should equal Bob's outgoing keys
+		assertMatches(kA.getCurrentIncomingKeys(), kB.getCurrentOutgoingKeys());
+		// Bob's incoming keys should equal Alice's outgoing keys
+		assertMatches(kB.getCurrentIncomingKeys(), kA.getCurrentOutgoingKeys());
+		// Update into the future
+		kA = transportCrypto.updateHandshakeKeys(kA, 456);
+		kB = transportCrypto.updateHandshakeKeys(kB, 456);
+		// Alice's incoming keys should equal Bob's outgoing keys
+		assertMatches(kA.getCurrentIncomingKeys(), kB.getCurrentOutgoingKeys());
+		// Bob's incoming keys should equal Alice's outgoing keys
+		assertMatches(kB.getCurrentIncomingKeys(), kA.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testPreviousKeysMatchContact() {
+		// Start in time period 123
+		HandshakeKeys kA = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys kB = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, false);
+		// Compare Alice's previous keys in period 456 with Bob's current keys
+		// in period 455
+		kA = transportCrypto.updateHandshakeKeys(kA, 456);
+		kB = transportCrypto.updateHandshakeKeys(kB, 455);
+		// Alice's previous incoming keys should equal Bob's current
+		// outgoing keys
+		assertMatches(kA.getPreviousIncomingKeys(),
+				kB.getCurrentOutgoingKeys());
+		// Compare Alice's current keys in period 456 with Bob's previous keys
+		// in period 457
+		kB = transportCrypto.updateHandshakeKeys(kB, 457);
+		// Bob's previous incoming keys should equal Alice's current
+		// outgoing keys
+		assertMatches(kB.getPreviousIncomingKeys(),
+				kA.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testNextKeysMatchContact() {
+		// Start in time period 123
+		HandshakeKeys kA = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys kB = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, false);
+		// Compare Alice's current keys in period 456 with Bob's next keys in
+		// period 455
+		kA = transportCrypto.updateHandshakeKeys(kA, 456);
+		kB = transportCrypto.updateHandshakeKeys(kB, 455);
+		// Bob's next incoming keys should equal Alice's current outgoing keys
+		assertMatches(kB.getNextIncomingKeys(), kA.getCurrentOutgoingKeys());
+		// Compare Alice's next keys in period 456 with Bob's current keys
+		// in period 457
+		kB = transportCrypto.updateHandshakeKeys(kB, 457);
+		// Alice's next incoming keys should equal Bob's current outgoing keys
+		assertMatches(kA.getNextIncomingKeys(), kB.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testRootKeyAffectsOutput() {
+		SecretKey rootKey1 = getSecretKey();
+		assertFalse(Arrays.equals(rootKey.getBytes(), rootKey1.getBytes()));
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey1, 123, true);
+		assertAllDifferent(k, k1);
+	}
+
+	@Test
+	public void testTransportIdAffectsOutput() {
+		TransportId transportId1 = getTransportId();
+		assertNotEquals(transportId.getString(), transportId1.getString());
+		HandshakeKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+				rootKey, 123, true);
+		HandshakeKeys k1 = transportCrypto.deriveHandshakeKeys(transportId1,
+				rootKey, 123, true);
+		assertAllDifferent(k, k1);
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/crypto/KeyDerivationTest.java

@@ -1,167 +0,0 @@
-package org.briarproject.bramble.crypto;
-
-import org.briarproject.bramble.api.Bytes;
-import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.api.crypto.TransportCrypto;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.transport.TransportKeys;
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSecureRandomProvider;
-import org.junit.Test;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-
-import static org.briarproject.bramble.test.TestUtils.getSecretKey;
-import static org.briarproject.bramble.test.TestUtils.getTransportId;
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-public class KeyDerivationTest extends BrambleTestCase {
-
-	private final CryptoComponent crypto =
-			new CryptoComponentImpl(new TestSecureRandomProvider(), null);
-	private final TransportCrypto transportCrypto =
-			new TransportCryptoImpl(crypto);
-	private final TransportId transportId = getTransportId();
-	private final SecretKey master = getSecretKey();
-
-	@Test
-	public void testKeysAreDistinct() {
-		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		assertAllDifferent(k);
-	}
-
-	@Test
-	public void testCurrentKeysMatchCurrentKeysOfContact() {
-		// Start in rotation period 123
-		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, false, true);
-		// Alice's incoming keys should equal Bob's outgoing keys
-		assertArrayEquals(kA.getCurrentIncomingKeys().getTagKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentIncomingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getHeaderKey().getBytes());
-		// Alice's outgoing keys should equal Bob's incoming keys
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getTagKey().getBytes(),
-				kB.getCurrentIncomingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentIncomingKeys().getHeaderKey().getBytes());
-		// Rotate into the future
-		kA = transportCrypto.rotateTransportKeys(kA, 456);
-		kB = transportCrypto.rotateTransportKeys(kB, 456);
-		// Alice's incoming keys should equal Bob's outgoing keys
-		assertArrayEquals(kA.getCurrentIncomingKeys().getTagKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentIncomingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getHeaderKey().getBytes());
-		// Alice's outgoing keys should equal Bob's incoming keys
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getTagKey().getBytes(),
-				kB.getCurrentIncomingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentIncomingKeys().getHeaderKey().getBytes());
-	}
-
-	@Test
-	public void testPreviousKeysMatchPreviousKeysOfContact() {
-		// Start in rotation period 123
-		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, false, true);
-		// Compare Alice's previous keys in period 456 with Bob's current keys
-		// in period 455
-		kA = transportCrypto.rotateTransportKeys(kA, 456);
-		kB = transportCrypto.rotateTransportKeys(kB, 455);
-		// Alice's previous incoming keys should equal Bob's outgoing keys
-		assertArrayEquals(kA.getPreviousIncomingKeys().getTagKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getTagKey().getBytes());
-		assertArrayEquals(
-				kA.getPreviousIncomingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getHeaderKey().getBytes());
-		// Compare Alice's current keys in period 456 with Bob's previous keys
-		// in period 457
-		kB = transportCrypto.rotateTransportKeys(kB, 457);
-		// Alice's outgoing keys should equal Bob's previous incoming keys
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getTagKey().getBytes(),
-				kB.getPreviousIncomingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getHeaderKey().getBytes(),
-				kB.getPreviousIncomingKeys().getHeaderKey().getBytes());
-	}
-
-	@Test
-	public void testNextKeysMatchNextKeysOfContact() {
-		// Start in rotation period 123
-		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, false, true);
-		// Compare Alice's current keys in period 456 with Bob's next keys in
-		// period 455
-		kA = transportCrypto.rotateTransportKeys(kA, 456);
-		kB = transportCrypto.rotateTransportKeys(kB, 455);
-		// Alice's outgoing keys should equal Bob's next incoming keys
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getTagKey().getBytes(),
-				kB.getNextIncomingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getCurrentOutgoingKeys().getHeaderKey().getBytes(),
-				kB.getNextIncomingKeys().getHeaderKey().getBytes());
-		// Compare Alice's next keys in period 456 with Bob's current keys
-		// in period 457
-		kB = transportCrypto.rotateTransportKeys(kB, 457);
-		// Alice's next incoming keys should equal Bob's outgoing keys
-		assertArrayEquals(kA.getNextIncomingKeys().getTagKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getTagKey().getBytes());
-		assertArrayEquals(kA.getNextIncomingKeys().getHeaderKey().getBytes(),
-				kB.getCurrentOutgoingKeys().getHeaderKey().getBytes());
-	}
-
-	@Test
-	public void testMasterKeyAffectsOutput() {
-		SecretKey master1 = getSecretKey();
-		assertFalse(Arrays.equals(master.getBytes(), master1.getBytes()));
-		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys k1 = transportCrypto.deriveTransportKeys(transportId,
-				master1, 123, true, true);
-		assertAllDifferent(k, k1);
-	}
-
-	@Test
-	public void testTransportIdAffectsOutput() {
-		TransportId transportId1 = getTransportId();
-		assertFalse(transportId.getString().equals(transportId1.getString()));
-		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
-				master, 123, true, true);
-		TransportKeys k1 = transportCrypto.deriveTransportKeys(transportId1,
-				master, 123, true, true);
-		assertAllDifferent(k, k1);
-	}
-
-	private void assertAllDifferent(TransportKeys... transportKeys) {
-		List<SecretKey> secretKeys = new ArrayList<>();
-		for (TransportKeys k : transportKeys) {
-			secretKeys.add(k.getPreviousIncomingKeys().getTagKey());
-			secretKeys.add(k.getPreviousIncomingKeys().getHeaderKey());
-			secretKeys.add(k.getCurrentIncomingKeys().getTagKey());
-			secretKeys.add(k.getCurrentIncomingKeys().getHeaderKey());
-			secretKeys.add(k.getNextIncomingKeys().getTagKey());
-			secretKeys.add(k.getNextIncomingKeys().getHeaderKey());
-			secretKeys.add(k.getCurrentOutgoingKeys().getTagKey());
-			secretKeys.add(k.getCurrentOutgoingKeys().getHeaderKey());
-		}
-		assertAllDifferent(secretKeys);
-	}
-
-	private void assertAllDifferent(List<SecretKey> keys) {
-		Set<Bytes> set = new HashSet<>();
-		for (SecretKey k : keys) assertTrue(set.add(new Bytes(k.getBytes())));
-	}
-}

bramble-core/src/test/java/org/briarproject/bramble/crypto/KeyDerivationTestUtils.java

@@ -0,0 +1,45 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.Bytes;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.transport.AbstractTransportKeys;
+import org.briarproject.bramble.api.transport.IncomingKeys;
+import org.briarproject.bramble.api.transport.OutgoingKeys;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertTrue;
+
+class KeyDerivationTestUtils {
+
+	static void assertAllDifferent(AbstractTransportKeys... transportKeys) {
+		List<SecretKey> secretKeys = new ArrayList<>();
+		for (AbstractTransportKeys k : transportKeys) {
+			secretKeys.add(k.getPreviousIncomingKeys().getTagKey());
+			secretKeys.add(k.getPreviousIncomingKeys().getHeaderKey());
+			secretKeys.add(k.getCurrentIncomingKeys().getTagKey());
+			secretKeys.add(k.getCurrentIncomingKeys().getHeaderKey());
+			secretKeys.add(k.getNextIncomingKeys().getTagKey());
+			secretKeys.add(k.getNextIncomingKeys().getHeaderKey());
+			secretKeys.add(k.getCurrentOutgoingKeys().getTagKey());
+			secretKeys.add(k.getCurrentOutgoingKeys().getHeaderKey());
+		}
+		assertAllDifferent(secretKeys);
+	}
+
+	static void assertAllDifferent(List<SecretKey> keys) {
+		Set<Bytes> set = new HashSet<>();
+		for (SecretKey k : keys) assertTrue(set.add(new Bytes(k.getBytes())));
+	}
+
+	static void assertMatches(IncomingKeys in, OutgoingKeys out) {
+		assertArrayEquals(in.getTagKey().getBytes(),
+				out.getTagKey().getBytes());
+		assertArrayEquals(in.getHeaderKey().getBytes(),
+				out.getHeaderKey().getBytes());
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/crypto/TransportKeyDerivationTest.java

@@ -0,0 +1,167 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.crypto.TransportCrypto;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.TransportKeys;
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.briarproject.bramble.crypto.KeyDerivationTestUtils.assertAllDifferent;
+import static org.briarproject.bramble.crypto.KeyDerivationTestUtils.assertMatches;
+import static org.briarproject.bramble.test.TestUtils.getSecretKey;
+import static org.briarproject.bramble.test.TestUtils.getTransportId;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertSame;
+
+public class TransportKeyDerivationTest extends BrambleTestCase {
+
+	private final CryptoComponent crypto =
+			new CryptoComponentImpl(new TestSecureRandomProvider(), null);
+	private final TransportCrypto transportCrypto =
+			new TransportCryptoImpl(crypto);
+	private final TransportId transportId = getTransportId();
+	private final SecretKey rootKey = getSecretKey();
+
+	@Test
+	public void testKeysAreDistinct() {
+		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, false, true);
+		assertAllDifferent(kA);
+		assertAllDifferent(kB);
+	}
+
+	@Test
+	public void testKeysAreNotRotatedToPreviousPeriod() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 122);
+		assertSame(k, k1);
+	}
+
+	@Test
+	public void testKeysAreNotRotatedToCurrentPeriod() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 123);
+		assertSame(k, k1);
+	}
+
+	@Test
+	public void testKeysAreRotatedByOnePeriod() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 124);
+		assertSame(k.getCurrentIncomingKeys(), k1.getPreviousIncomingKeys());
+		assertSame(k.getNextIncomingKeys(), k1.getCurrentIncomingKeys());
+	}
+
+	@Test
+	public void testKeysAreRotatedByTwoPeriods() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 125);
+		assertSame(k.getNextIncomingKeys(), k1.getPreviousIncomingKeys());
+	}
+
+	@Test
+	public void testKeysAreRotatedByThreePeriods() {
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.rotateTransportKeys(k, 126);
+		assertAllDifferent(k, k1);
+	}
+
+	@Test
+	public void testCurrentKeysMatchContact() {
+		// Start in time period 123
+		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, false, true);
+		// Alice's incoming keys should equal Bob's outgoing keys
+		assertMatches(kA.getCurrentIncomingKeys(), kB.getCurrentOutgoingKeys());
+		// Bob's incoming keys should equal Alice's outgoing keys
+		assertMatches(kB.getCurrentIncomingKeys(), kA.getCurrentOutgoingKeys());
+		// Rotate into the future
+		kA = transportCrypto.rotateTransportKeys(kA, 456);
+		kB = transportCrypto.rotateTransportKeys(kB, 456);
+		// Alice's incoming keys should equal Bob's outgoing keys
+		assertMatches(kA.getCurrentIncomingKeys(), kB.getCurrentOutgoingKeys());
+		// Bob's incoming keys should equal Alice's outgoing keys
+		assertMatches(kB.getCurrentIncomingKeys(), kA.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testPreviousKeysMatchContact() {
+		// Start in time period 123
+		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, false, true);
+		// Compare Alice's previous keys in period 456 with Bob's current keys
+		// in period 455
+		kA = transportCrypto.rotateTransportKeys(kA, 456);
+		kB = transportCrypto.rotateTransportKeys(kB, 455);
+		// Alice's previous incoming keys should equal Bob's current
+		// outgoing keys
+		assertMatches(kA.getPreviousIncomingKeys(),
+				kB.getCurrentOutgoingKeys());
+		// Compare Alice's current keys in period 456 with Bob's previous keys
+		// in period 457
+		kB = transportCrypto.rotateTransportKeys(kB, 457);
+		// Bob's previous incoming keys should equal Alice's current
+		// outgoing keys
+		assertMatches(kB.getPreviousIncomingKeys(),
+				kA.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testNextKeysMatchContact() {
+		// Start in time period 123
+		TransportKeys kA = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys kB = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, false, true);
+		// Compare Alice's current keys in period 456 with Bob's next keys in
+		// period 455
+		kA = transportCrypto.rotateTransportKeys(kA, 456);
+		kB = transportCrypto.rotateTransportKeys(kB, 455);
+		// Bob's next incoming keys should equal Alice's current outgoing keys
+		assertMatches(kB.getNextIncomingKeys(), kA.getCurrentOutgoingKeys());
+		// Compare Alice's next keys in period 456 with Bob's current keys
+		// in period 457
+		kB = transportCrypto.rotateTransportKeys(kB, 457);
+		// Alice's next incoming keys should equal Bob's current outgoing keys
+		assertMatches(kA.getNextIncomingKeys(), kB.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testRootKeyAffectsOutput() {
+		SecretKey rootKey1 = getSecretKey();
+		assertFalse(Arrays.equals(rootKey.getBytes(), rootKey1.getBytes()));
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.deriveTransportKeys(transportId,
+				rootKey1, 123, true, true);
+		assertAllDifferent(k, k1);
+	}
+
+	@Test
+	public void testTransportIdAffectsOutput() {
+		TransportId transportId1 = getTransportId();
+		assertNotEquals(transportId.getString(), transportId1.getString());
+		TransportKeys k = transportCrypto.deriveTransportKeys(transportId,
+				rootKey, 123, true, true);
+		TransportKeys k1 = transportCrypto.deriveTransportKeys(transportId1,
+				rootKey, 123, true, true);
+		assertAllDifferent(k, k1);
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseComponentImplTest.java

@@ -2,9 +2,9 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
-import org.briarproject.bramble.api.contact.event.ContactStatusChangedEvent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.ContactExistsException;
 import org.briarproject.bramble.api.db.DatabaseComponent;
@@ -13,7 +13,9 @@ import org.briarproject.bramble.api.db.NoSuchContactException;
 import org.briarproject.bramble.api.db.NoSuchGroupException;
 import org.briarproject.bramble.api.db.NoSuchLocalAuthorException;
 import org.briarproject.bramble.api.db.NoSuchMessageException;
+import org.briarproject.bramble.api.db.NoSuchPendingContactException;
 import org.briarproject.bramble.api.db.NoSuchTransportException;
+import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.LocalAuthor;
@@ -43,18 +45,21 @@ import org.briarproject.bramble.api.sync.event.MessageToAckEvent;
 import org.briarproject.bramble.api.sync.event.MessageToRequestEvent;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
 import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
 import org.briarproject.bramble.api.transport.IncomingKeys;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.CaptureArgumentAction;
 import org.jmock.Expectations;
+import org.jmock.Sequence;
 import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicReference;
 
 import static java.util.Arrays.asList;
@@ -70,13 +75,13 @@ import static org.briarproject.bramble.api.transport.TransportConstants.REORDERI
 import static org.briarproject.bramble.db.DatabaseConstants.MAX_OFFERED_MESSAGES;
 import static org.briarproject.bramble.test.TestUtils.getAuthor;
 import static org.briarproject.bramble.test.TestUtils.getClientId;
+import static org.briarproject.bramble.test.TestUtils.getContact;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getLocalAuthor;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.briarproject.bramble.test.TestUtils.getTransportId;
-import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -87,9 +92,10 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 
 	@SuppressWarnings("unchecked")
 	private final Database<Object> database = context.mock(Database.class);
-	private final ShutdownManager shutdown =
+	private final ShutdownManager shutdownManager =
 			context.mock(ShutdownManager.class);
 	private final EventBus eventBus = context.mock(EventBus.class);
+	private final Executor eventExecutor = context.mock(Executor.class);
 
 	private final SecretKey key = getSecretKey();
 	private final Object txn = new Object();
@@ -107,7 +113,8 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 	private final int maxLatency;
 	private final ContactId contactId;
 	private final Contact contact;
-	private final KeySetId keySetId;
+	private final TransportKeySetId keySetId;
+	private final PendingContactId pendingContactId;
 
 	public DatabaseComponentImplTest() {
 		clientId = getClientId();
@@ -116,7 +123,6 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		groupId = group.getId();
 		author = getAuthor();
 		localAuthor = getLocalAuthor();
-		alias = getRandomString(5);
 		message = getMessage(groupId);
 		message1 = getMessage(groupId);
 		messageId = message.getId();
@@ -125,16 +131,18 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		metadata.put("foo", new byte[] {'b', 'a', 'r'});
 		transportId = getTransportId();
 		maxLatency = Integer.MAX_VALUE;
-		contactId = new ContactId(234);
-		contact = new Contact(contactId, author, localAuthor.getId(), alias,
-				true, true);
-		keySetId = new KeySetId(345);
+		contact = getContact(author, true);
+		contactId = contact.getId();
+		alias = contact.getAlias();
+		keySetId = new TransportKeySetId(345);
+		pendingContactId = new PendingContactId(getRandomId());
 	}
 
 	private DatabaseComponent createDatabaseComponent(Database<Object> database,
-			EventBus eventBus, ShutdownManager shutdown) {
+			EventBus eventBus, Executor eventExecutor,
+			ShutdownManager shutdownManager) {
 		return new DatabaseComponentImpl<>(database, Object.class, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 	}
 
 	@Test
@@ -144,7 +152,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			// open()
 			oneOf(database).open(key, null);
 			will(returnValue(false));
-			oneOf(shutdown).addShutdownHook(with(any(Runnable.class)));
+			oneOf(shutdownManager).addShutdownHook(with(any(Runnable.class)));
 			will(returnValue(shutdownHandle));
 			// startTransaction()
 			oneOf(database).startTransaction();
@@ -155,19 +163,13 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).addLocalAuthor(txn, localAuthor);
 			oneOf(eventBus).broadcast(with(any(LocalAuthorAddedEvent.class)));
 			// addContact()
-			oneOf(database).containsLocalAuthor(txn, localAuthor.getId());
-			will(returnValue(true));
 			oneOf(database).containsLocalAuthor(txn, author.getId());
 			will(returnValue(false));
-			oneOf(database).containsContact(txn, author.getId(),
-					localAuthor.getId());
+			oneOf(database).containsContact(txn, author.getId());
 			will(returnValue(false));
-			oneOf(database).addContact(txn, author, localAuthor.getId(),
-					true, true);
+			oneOf(database).addContact(txn, author, true);
 			will(returnValue(contactId));
 			oneOf(eventBus).broadcast(with(any(ContactAddedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(
-					ContactStatusChangedEvent.class)));
 			// getContacts()
 			oneOf(database).getContacts(txn);
 			will(returnValue(singletonList(contact)));
@@ -207,13 +209,12 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).close();
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		assertFalse(db.open(key, null));
 		db.transaction(false, transaction -> {
 			db.addLocalAuthor(transaction, localAuthor);
-			assertEquals(contactId, db.addContact(transaction, author,
-					localAuthor.getId(), true, true));
+			assertEquals(contactId, db.addContact(transaction, author, true));
 			assertEquals(singletonList(contact),
 					db.getContacts(transaction));
 			db.addGroup(transaction, group); // First time - listeners called
@@ -238,7 +239,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.addLocalMessage(transaction, message, metadata, true));
@@ -263,7 +264,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageSharedEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.addLocalMessage(transaction, message, metadata, true));
@@ -274,14 +275,25 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			throws Exception {
 		context.checking(new Expectations() {{
 			// Check whether the contact is in the DB (which it's not)
-			exactly(17).of(database).startTransaction();
+			exactly(18).of(database).startTransaction();
 			will(returnValue(txn));
 			exactly(17).of(database).containsContact(txn, contactId);
 			will(returnValue(false));
-			exactly(17).of(database).abortTransaction(txn);
+			oneOf(database).containsContact(txn, author.getId());
+			will(returnValue(false));
+			exactly(18).of(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
+
+		try {
+			db.transaction(false, transaction ->
+					db.addHandshakeKeys(transaction, contactId,
+							createHandshakeKeys()));
+			fail();
+		} catch (NoSuchContactException expected) {
+			// Expected
+		}
 
 		try {
 			db.transaction(false, transaction ->
@@ -332,6 +344,14 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			// Expected
 		}
 
+		try {
+			db.transaction(false, transaction ->
+					db.getContact(transaction, author.getId()));
+			fail();
+		} catch (NoSuchContactException expected) {
+			// Expected
+		}
+
 		try {
 			db.transaction(false, transaction ->
 					db.getMessageStatus(transaction, contactId, groupId));
@@ -399,14 +419,6 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			// Expected
 		}
 
-		try {
-			db.transaction(false, transaction ->
-					db.setContactActive(transaction, contactId, true));
-			fail();
-		} catch (NoSuchContactException expected) {
-			// Expected
-		}
-
 		try {
 			db.transaction(false, transaction ->
 					db.setContactAlias(transaction, contactId, alias));
@@ -430,24 +442,15 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			throws Exception {
 		context.checking(new Expectations() {{
 			// Check whether the pseudonym is in the DB (which it's not)
-			exactly(3).of(database).startTransaction();
+			exactly(2).of(database).startTransaction();
 			will(returnValue(txn));
-			exactly(3).of(database).containsLocalAuthor(txn,
+			exactly(2).of(database).containsLocalAuthor(txn,
 					localAuthor.getId());
 			will(returnValue(false));
-			exactly(3).of(database).abortTransaction(txn);
+			exactly(2).of(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
-
-		try {
-			db.transaction(false, transaction ->
-					db.addContact(transaction, author, localAuthor.getId(),
-							true, true));
-			fail();
-		} catch (NoSuchLocalAuthorException expected) {
-			// Expected
-		}
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -481,7 +484,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			will(returnValue(true));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -565,7 +568,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			will(returnValue(true));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -668,7 +671,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			exactly(5).of(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
@@ -713,6 +716,39 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 	}
 
+	@Test
+	public void testVariousMethodsThrowExceptionIfPendingContactIsMissing()
+			throws Exception {
+		context.checking(new Expectations() {{
+			// Check whether the pending contact is in the DB (which it's not)
+			exactly(2).of(database).startTransaction();
+			will(returnValue(txn));
+			exactly(2).of(database).containsPendingContact(txn,
+					pendingContactId);
+			will(returnValue(false));
+			exactly(2).of(database).abortTransaction(txn);
+		}});
+		DatabaseComponent db = createDatabaseComponent(database, eventBus,
+				eventExecutor, shutdownManager);
+
+		try {
+			db.transaction(false, transaction ->
+					db.addHandshakeKeys(transaction, pendingContactId,
+							createHandshakeKeys()));
+			fail();
+		} catch (NoSuchPendingContactException expected) {
+			// Expected
+		}
+
+		try {
+			db.transaction(false, transaction ->
+					db.removePendingContact(transaction, pendingContactId));
+			fail();
+		} catch (NoSuchPendingContactException expected) {
+			// Expected
+		}
+	}
+
 	@Test
 	public void testGenerateAck() throws Exception {
 		Collection<MessageId> messagesToAck = asList(messageId, messageId1);
@@ -727,7 +763,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			Ack a = db.generateAck(transaction, contactId, 123);
@@ -761,7 +797,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessagesSentEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				assertEquals(messages, db.generateBatch(transaction, contactId,
@@ -786,7 +822,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			Offer o = db.generateOffer(transaction, contactId, 123, maxLatency);
@@ -810,7 +846,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			Request r = db.generateRequest(transaction, contactId, 123);
@@ -844,7 +880,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessagesSentEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				assertEquals(messages, db.generateRequestedBatch(transaction,
@@ -865,7 +901,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessagesAckedEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			Ack a = new Ack(singletonList(messageId));
@@ -903,7 +939,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageToAckEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			// Receive the message twice
@@ -931,7 +967,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageToAckEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.receiveMessage(transaction, contactId, message));
@@ -949,7 +985,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.receiveMessage(transaction, contactId, message));
@@ -989,7 +1025,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageToRequestEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		Offer o = new Offer(asList(messageId, messageId1,
 				messageId2, messageId3));
@@ -1012,7 +1048,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageRequestedEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		Request r = new Request(singletonList(messageId));
 		db.transaction(false, transaction ->
@@ -1042,7 +1078,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 					GroupVisibilityUpdatedEvent.class, 0));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.setGroupVisibility(transaction, contactId, groupId,
@@ -1076,7 +1112,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 					GroupVisibilityUpdatedEvent.class, 0));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.setGroupVisibility(transaction, contactId, groupId,
@@ -1102,7 +1138,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
 				db.setGroupVisibility(transaction, contactId, groupId,
@@ -1112,8 +1148,9 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 	@Test
 	public void testTransportKeys() throws Exception {
 		TransportKeys transportKeys = createTransportKeys();
-		KeySet ks = new KeySet(keySetId, contactId, transportKeys);
-		Collection<KeySet> keys = singletonList(ks);
+		TransportKeySet ks =
+				new TransportKeySet(keySetId, contactId, transportKeys);
+		Collection<TransportKeySet> keys = singletonList(ks);
 
 		context.checking(new Expectations() {{
 			// startTransaction()
@@ -1132,7 +1169,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			db.updateTransportKeys(transaction, keys);
@@ -1171,7 +1208,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(true, transaction -> {
 			// With visible group - return stored status
@@ -1221,7 +1258,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).commitTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(true, transaction -> {
 			// With visible group - return stored status
@@ -1240,6 +1277,27 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		});
 	}
 
+	private HandshakeKeys createHandshakeKeys() {
+		SecretKey inPrevTagKey = getSecretKey();
+		SecretKey inPrevHeaderKey = getSecretKey();
+		IncomingKeys inPrev = new IncomingKeys(inPrevTagKey, inPrevHeaderKey,
+				1, 123, new byte[4]);
+		SecretKey inCurrTagKey = getSecretKey();
+		SecretKey inCurrHeaderKey = getSecretKey();
+		IncomingKeys inCurr = new IncomingKeys(inCurrTagKey, inCurrHeaderKey,
+				2, 234, new byte[4]);
+		SecretKey inNextTagKey = getSecretKey();
+		SecretKey inNextHeaderKey = getSecretKey();
+		IncomingKeys inNext = new IncomingKeys(inNextTagKey, inNextHeaderKey,
+				3, 345, new byte[4]);
+		SecretKey outCurrTagKey = getSecretKey();
+		SecretKey outCurrHeaderKey = getSecretKey();
+		OutgoingKeys outCurr = new OutgoingKeys(outCurrTagKey, outCurrHeaderKey,
+				2, 456, true);
+		return new HandshakeKeys(transportId, inPrev, inCurr, inNext, outCurr,
+				getSecretKey(), true);
+	}
+
 	private TransportKeys createTransportKeys() {
 		SecretKey inPrevTagKey = getSecretKey();
 		SecretKey inPrevHeaderKey = getSecretKey();
@@ -1287,7 +1345,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}});
 
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction -> {
 			// First merge should broadcast an event
@@ -1330,7 +1388,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}});
 
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		assertNotNull(db.startTransaction(firstTxnReadOnly));
 		db.startTransaction(secondTxnReadOnly);
@@ -1342,8 +1400,6 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		context.checking(new Expectations() {{
 			oneOf(database).startTransaction();
 			will(returnValue(txn));
-			oneOf(database).containsLocalAuthor(txn, localAuthor.getId());
-			will(returnValue(true));
 			// Contact is a local identity
 			oneOf(database).containsLocalAuthor(txn, author.getId());
 			will(returnValue(true));
@@ -1351,12 +1407,11 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}});
 
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
-					db.addContact(transaction, author, localAuthor.getId(),
-							true, true));
+					db.addContact(transaction, author, true));
 			fail();
 		} catch (ContactExistsException expected) {
 			// Expected
@@ -1368,24 +1423,20 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		context.checking(new Expectations() {{
 			oneOf(database).startTransaction();
 			will(returnValue(txn));
-			oneOf(database).containsLocalAuthor(txn, localAuthor.getId());
-			will(returnValue(true));
 			oneOf(database).containsLocalAuthor(txn, author.getId());
 			will(returnValue(false));
-			// Contact already exists for this local identity
-			oneOf(database).containsContact(txn, author.getId(),
-					localAuthor.getId());
+			// Contact already exists
+			oneOf(database).containsContact(txn, author.getId());
 			will(returnValue(true));
 			oneOf(database).abortTransaction(txn);
 		}});
 
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		try {
 			db.transaction(false, transaction ->
-					db.addContact(transaction, author, localAuthor.getId(),
-							true, true));
+					db.addContact(transaction, author, true));
 			fail();
 		} catch (ContactExistsException expected) {
 			// Expected
@@ -1401,7 +1452,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			// open()
 			oneOf(database).open(key, null);
 			will(returnValue(false));
-			oneOf(shutdown).addShutdownHook(with(any(Runnable.class)));
+			oneOf(shutdownManager).addShutdownHook(with(any(Runnable.class)));
 			will(returnValue(shutdownHandle));
 			// startTransaction()
 			oneOf(database).startTransaction();
@@ -1441,7 +1492,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).close();
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				shutdown);
+				eventExecutor, shutdownManager);
 
 		assertFalse(db.open(key, null));
 		db.transaction(false, transaction -> {
@@ -1455,4 +1506,43 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		});
 		db.close();
 	}
+
+	@Test
+	public void testCommitActionsOccurInOrder() throws Exception {
+		TestEvent action1 = new TestEvent();
+		Runnable action2 = () -> {
+		};
+		TestEvent action3 = new TestEvent();
+		Runnable action4 = () -> {
+		};
+
+		Sequence sequence = context.sequence("sequence");
+		context.checking(new Expectations() {{
+			oneOf(database).startTransaction();
+			will(returnValue(txn));
+			inSequence(sequence);
+			oneOf(database).commitTransaction(txn);
+			inSequence(sequence);
+			oneOf(eventBus).broadcast(action1);
+			inSequence(sequence);
+			oneOf(eventExecutor).execute(action2);
+			inSequence(sequence);
+			oneOf(eventBus).broadcast(action3);
+			inSequence(sequence);
+			oneOf(eventExecutor).execute(action4);
+			inSequence(sequence);
+		}});
+		DatabaseComponent db = createDatabaseComponent(database, eventBus,
+				eventExecutor, shutdownManager);
+
+		db.transaction(false, transaction -> {
+			transaction.attach(action1);
+			transaction.attach(action2);
+			transaction.attach(action3);
+			transaction.attach(action4);
+		});
+	}
+
+	private static class TestEvent extends Event {
+	}
 }

bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseMigrationTest.java

@@ -45,8 +45,7 @@ public abstract class DatabaseMigrationTest extends BrambleMockTestCase {
 	private final Migration<Connection> migration1 =
 			context.mock(Migration.class, "migration1");
 
-	protected final DatabaseConfig config =
-			new TestDatabaseConfig(testDir, 1024 * 1024);
+	protected final DatabaseConfig config = new TestDatabaseConfig(testDir);
 	protected final MessageFactory messageFactory = new TestMessageFactory();
 	protected final SecretKey key = getSecretKey();
 	protected final Clock clock = new SystemClock();

bramble-core/src/test/java/org/briarproject/bramble/db/DatabasePerformanceComparisonTest.java

@@ -76,8 +76,8 @@ public abstract class DatabasePerformanceComparisonTest
 	private Database<Connection> openDatabase(boolean conditionA)
 			throws DbException {
 		Database<Connection> db = createDatabase(conditionA,
-				new TestDatabaseConfig(testDir, MAX_SIZE),
-				new TestMessageFactory(), new SystemClock());
+				new TestDatabaseConfig(testDir), new TestMessageFactory(),
+				new SystemClock());
 		db.open(databaseKey, null);
 		return db;
 	}

bramble-core/src/test/java/org/briarproject/bramble/db/DatabasePerformanceTest.java

@@ -4,7 +4,6 @@ import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Metadata;
-import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.bramble.api.sync.Group;
@@ -49,9 +48,6 @@ import static org.junit.Assert.assertTrue;
 
 public abstract class DatabasePerformanceTest extends BrambleTestCase {
 
-	private static final int ONE_MEGABYTE = 1024 * 1024;
-	static final int MAX_SIZE = 100 * ONE_MEGABYTE;
-
 	/**
 	 * How many contacts to simulate.
 	 */
@@ -134,11 +130,10 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 
 	@Test
 	public void testContainsContactByAuthorId() throws Exception {
-		String name = "containsContact(T, AuthorId, AuthorId)";
+		String name = "containsContact(T, AuthorId)";
 		benchmark(name, db -> {
 			Connection txn = db.startTransaction();
-			AuthorId remote = pickRandom(contacts).getAuthor().getId();
-			db.containsContact(txn, remote, localAuthor.getId());
+			db.containsContact(txn, pickRandom(contacts).getAuthor().getId());
 			db.commitTransaction(txn);
 		});
 	}
@@ -205,7 +200,7 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testGetContact() throws Exception {
+	public void testGetContactByContactId() throws Exception {
 		String name = "getContact(T, ContactId)";
 		benchmark(name, db -> {
 			Connection txn = db.startTransaction();
@@ -214,6 +209,16 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 		});
 	}
 
+	@Test
+	public void testGetContactByAuthorId() throws Exception {
+		String name = "getContact(T, AuthorId)";
+		benchmark(name, db -> {
+			Connection txn = db.startTransaction();
+			db.getContact(txn, pickRandom(contacts).getAuthor().getId());
+			db.commitTransaction(txn);
+		});
+	}
+
 	@Test
 	public void testGetContacts() throws Exception {
 		String name = "getContacts(T)";
@@ -224,27 +229,6 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 		});
 	}
 
-	@Test
-	public void testGetContactsByRemoteAuthorId() throws Exception {
-		String name = "getContactsByAuthorId(T, AuthorId)";
-		benchmark(name, db -> {
-			Connection txn = db.startTransaction();
-			AuthorId remote = pickRandom(contacts).getAuthor().getId();
-			db.getContactsByAuthorId(txn, remote);
-			db.commitTransaction(txn);
-		});
-	}
-
-	@Test
-	public void testGetContactsByLocalAuthorId() throws Exception {
-		String name = "getContacts(T, AuthorId)";
-		benchmark(name, db -> {
-			Connection txn = db.startTransaction();
-			db.getContacts(txn, localAuthor.getId());
-			db.commitTransaction(txn);
-		});
-	}
-
 	@Test
 	public void testGetGroup() throws Exception {
 		String name = "getGroup(T, GroupId)";
@@ -548,8 +532,7 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 		db.addLocalAuthor(txn, localAuthor);
 		for (int i = 0; i < CONTACTS; i++) {
-			ContactId c = db.addContact(txn, getAuthor(), localAuthor.getId(),
-					random.nextBoolean(), true);
+			ContactId c = db.addContact(txn, getAuthor(), random.nextBoolean());
 			contacts.add(db.getContact(txn, c));
 			contactGroups.put(c, new ArrayList<>());
 			for (int j = 0; j < GROUPS_PER_CONTACT; j++) {

bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseTraceTest.java

@@ -48,8 +48,8 @@ public abstract class DatabaseTraceTest extends DatabasePerformanceTest {
 
 	private Database<Connection> openDatabase() throws DbException {
 		Database<Connection> db = createDatabase(
-				new TestDatabaseConfig(testDir, MAX_SIZE),
-				new TestMessageFactory(), new SystemClock());
+				new TestDatabaseConfig(testDir), new TestMessageFactory(),
+				new SystemClock());
 		db.open(databaseKey, null);
 		return db;
 	}

bramble-core/src/test/java/org/briarproject/bramble/db/JdbcDatabaseTest.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.db.DbException;
@@ -20,10 +21,13 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.transport.HandshakeKeySet;
+import org.briarproject.bramble.api.transport.HandshakeKeySetId;
+import org.briarproject.bramble.api.transport.HandshakeKeys;
 import org.briarproject.bramble.api.transport.IncomingKeys;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.system.SystemClock;
 import org.briarproject.bramble.test.BrambleTestCase;
@@ -52,12 +56,12 @@ import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
 import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.briarproject.bramble.api.contact.PendingContactState.FAILED;
 import static org.briarproject.bramble.api.db.Metadata.REMOVE;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
-import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
 import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
 import static org.briarproject.bramble.api.sync.validation.MessageState.INVALID;
 import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
@@ -71,6 +75,7 @@ import static org.briarproject.bramble.test.TestUtils.getClientId;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getLocalAuthor;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
+import static org.briarproject.bramble.test.TestUtils.getPendingContact;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
@@ -79,7 +84,6 @@ import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
@@ -88,11 +92,9 @@ import static org.junit.Assert.fail;
 public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 	private static final int ONE_MEGABYTE = 1024 * 1024;
-	private static final int MAX_SIZE = 5 * ONE_MEGABYTE;
 	// All our transports use a maximum latency of 30 seconds
 	private static final int MAX_LATENCY = 30 * 1000;
 
-
 	private final SecretKey key = getSecretKey();
 	private final File testDir = getTestDirectory();
 	private final GroupId groupId;
@@ -105,7 +107,9 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 	private final MessageId messageId;
 	private final TransportId transportId;
 	private final ContactId contactId;
-	private final KeySetId keySetId, keySetId1;
+	private final TransportKeySetId keySetId, keySetId1;
+	private final HandshakeKeySetId handshakeKeySetId, handshakeKeySetId1;
+	private final PendingContact pendingContact;
 	private final Random random = new Random();
 
 	JdbcDatabaseTest() {
@@ -119,8 +123,11 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		messageId = message.getId();
 		transportId = getTransportId();
 		contactId = new ContactId(1);
-		keySetId = new KeySetId(1);
-		keySetId1 = new KeySetId(2);
+		keySetId = new TransportKeySetId(1);
+		keySetId1 = new TransportKeySetId(2);
+		handshakeKeySetId = new HandshakeKeySetId(1);
+		handshakeKeySetId1 = new HandshakeKeySetId(2);
+		pendingContact = getPendingContact();
 	}
 
 	protected abstract JdbcDatabase createDatabase(DatabaseConfig config,
@@ -138,8 +145,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 		assertFalse(db.containsContact(txn, contactId));
 		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		assertTrue(db.containsContact(txn, contactId));
 		assertFalse(db.containsGroup(txn, groupId));
 		db.addGroup(txn, group);
@@ -200,9 +206,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a shared group and a shared message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 		db.addMessage(txn, message, DELIVERED, true, null);
@@ -231,9 +235,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a shared group and a shared but unvalidated message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 		db.addMessage(txn, message, UNKNOWN, true, null);
@@ -276,9 +278,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, an invisible group and a shared message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addMessage(txn, message, DELIVERED, true, null);
 
@@ -327,9 +327,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a shared group and an unshared message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 		db.addMessage(txn, message, DELIVERED, false, null);
@@ -358,17 +356,14 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a shared group and a shared message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 		db.addMessage(txn, message, DELIVERED, true, null);
 
 		// The message is sendable, but too large to send
-		Collection<MessageId> ids =
-				db.getMessagesToSend(txn, contactId, message.getRawLength() - 1,
-						MAX_LATENCY);
+		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
+				message.getRawLength() - 1, MAX_LATENCY);
 		assertTrue(ids.isEmpty());
 		// The message is just the right size to send
 		ids = db.getMessagesToSend(txn, contactId, message.getRawLength(),
@@ -385,9 +380,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact and a visible group
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, false);
 
@@ -426,9 +419,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a shared group and a shared message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 		db.addMessage(txn, message, DELIVERED, true, null);
@@ -454,29 +445,6 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.close();
 	}
 
-	@Test
-	public void testGetFreeSpace() throws Exception {
-		Message message = getMessage(groupId, MAX_MESSAGE_BODY_LENGTH);
-		Database<Connection> db = open(false);
-
-		// Sanity check: there should be enough space on disk for this test
-		assertTrue(testDir.getFreeSpace() > MAX_SIZE);
-
-		// The free space should not be more than the allowed maximum size
-		long free = db.getFreeSpace();
-		assertTrue(free <= MAX_SIZE);
-		assertTrue(free > 0);
-
-		// Storing a message should reduce the free space
-		Connection txn = db.startTransaction();
-		db.addGroup(txn, group);
-		db.addMessage(txn, message, DELIVERED, true, null);
-		db.commitTransaction(txn);
-		assertTrue(db.getFreeSpace() < free);
-
-		db.close();
-	}
-
 	@Test
 	public void testCloseWaitsForCommit() throws Exception {
 		CountDownLatch closing = new CountDownLatch(1);
@@ -581,9 +549,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact and a shared group
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 
@@ -601,9 +567,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 
 		// The group is not in the database
 		assertFalse(db.containsVisibleMessage(txn, contactId, messageId));
@@ -619,9 +583,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, an invisible group and a message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addMessage(txn, message, DELIVERED, true, null);
 
@@ -638,9 +600,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact and a group
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 
 		// The group should not be visible to the contact
@@ -678,10 +638,10 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 	@Test
 	public void testTransportKeys() throws Exception {
-		long rotationPeriod = 123, rotationPeriod1 = 234;
+		long timePeriod = 123, timePeriod1 = 234;
 		boolean active = random.nextBoolean();
-		TransportKeys keys = createTransportKeys(rotationPeriod, active);
-		TransportKeys keys1 = createTransportKeys(rotationPeriod1, active);
+		TransportKeys keys = createTransportKeys(timePeriod, active);
+		TransportKeys keys1 = createTransportKeys(timePeriod1, active);
 
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();
@@ -690,43 +650,44 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertEquals(emptyList(), db.getTransportKeys(txn, transportId));
 
 		// Add the contact, the transport and the transport keys
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, active));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addTransport(txn, transportId, 123);
 		assertEquals(keySetId, db.addTransportKeys(txn, contactId, keys));
 		assertEquals(keySetId1, db.addTransportKeys(txn, contactId, keys1));
 
 		// Retrieve the transport keys
-		Collection<KeySet> allKeys = db.getTransportKeys(txn, transportId);
+		Collection<TransportKeySet> allKeys =
+				db.getTransportKeys(txn, transportId);
 		assertEquals(2, allKeys.size());
-		for (KeySet ks : allKeys) {
+		for (TransportKeySet ks : allKeys) {
 			assertEquals(contactId, ks.getContactId());
 			if (ks.getKeySetId().equals(keySetId)) {
-				assertKeysEquals(keys, ks.getTransportKeys());
+				assertKeysEquals(keys, ks.getKeys());
 			} else {
 				assertEquals(keySetId1, ks.getKeySetId());
-				assertKeysEquals(keys1, ks.getTransportKeys());
+				assertKeysEquals(keys1, ks.getKeys());
 			}
 		}
 
 		// Rotate the transport keys
-		TransportKeys rotated = createTransportKeys(rotationPeriod + 1, active);
+		TransportKeys rotated = createTransportKeys(timePeriod + 1, active);
 		TransportKeys rotated1 =
-				createTransportKeys(rotationPeriod1 + 1, active);
-		db.updateTransportKeys(txn, new KeySet(keySetId, contactId, rotated));
-		db.updateTransportKeys(txn, new KeySet(keySetId1, contactId, rotated1));
+				createTransportKeys(timePeriod1 + 1, active);
+		db.updateTransportKeys(txn, new TransportKeySet(keySetId, contactId,
+				rotated));
+		db.updateTransportKeys(txn, new TransportKeySet(keySetId1, contactId,
+				rotated1));
 
 		// Retrieve the transport keys again
 		allKeys = db.getTransportKeys(txn, transportId);
 		assertEquals(2, allKeys.size());
-		for (KeySet ks : allKeys) {
+		for (TransportKeySet ks : allKeys) {
 			assertEquals(contactId, ks.getContactId());
 			if (ks.getKeySetId().equals(keySetId)) {
-				assertKeysEquals(rotated, ks.getTransportKeys());
+				assertKeysEquals(rotated, ks.getKeys());
 			} else {
 				assertEquals(keySetId1, ks.getKeySetId());
-				assertKeysEquals(rotated1, ks.getTransportKeys());
+				assertKeysEquals(rotated1, ks.getKeys());
 			}
 		}
 
@@ -741,7 +702,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 	private void assertKeysEquals(TransportKeys expected,
 			TransportKeys actual) {
 		assertEquals(expected.getTransportId(), actual.getTransportId());
-		assertEquals(expected.getRotationPeriod(), actual.getRotationPeriod());
+		assertEquals(expected.getTimePeriod(), actual.getTimePeriod());
 		assertKeysEquals(expected.getPreviousIncomingKeys(),
 				actual.getPreviousIncomingKeys());
 		assertKeysEquals(expected.getCurrentIncomingKeys(),
@@ -757,7 +718,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				actual.getTagKey().getBytes());
 		assertArrayEquals(expected.getHeaderKey().getBytes(),
 				actual.getHeaderKey().getBytes());
-		assertEquals(expected.getRotationPeriod(), actual.getRotationPeriod());
+		assertEquals(expected.getTimePeriod(), actual.getTimePeriod());
 		assertEquals(expected.getWindowBase(), actual.getWindowBase());
 		assertArrayEquals(expected.getWindowBitmap(), actual.getWindowBitmap());
 	}
@@ -767,39 +728,240 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				actual.getTagKey().getBytes());
 		assertArrayEquals(expected.getHeaderKey().getBytes(),
 				actual.getHeaderKey().getBytes());
-		assertEquals(expected.getRotationPeriod(), actual.getRotationPeriod());
+		assertEquals(expected.getTimePeriod(), actual.getTimePeriod());
 		assertEquals(expected.getStreamCounter(), actual.getStreamCounter());
 		assertEquals(expected.isActive(), actual.isActive());
 	}
 
+	@Test
+	public void testHandshakeKeys() throws Exception {
+		long timePeriod = 123, timePeriod1 = 234;
+		boolean alice = random.nextBoolean();
+		SecretKey rootKey = getSecretKey();
+		SecretKey rootKey1 = getSecretKey();
+		HandshakeKeys keys = createHandshakeKeys(timePeriod, rootKey, alice);
+		HandshakeKeys keys1 = createHandshakeKeys(timePeriod1, rootKey1, alice);
+
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Initially there should be no handshake keys in the database
+		assertEquals(emptyList(), db.getHandshakeKeys(txn, transportId));
+
+		// Add the contact, the transport and the handshake keys
+		assertEquals(contactId, db.addContact(txn, author, true));
+		db.addTransport(txn, transportId, 123);
+		assertEquals(handshakeKeySetId,
+				db.addHandshakeKeys(txn, contactId, keys));
+		assertEquals(handshakeKeySetId1,
+				db.addHandshakeKeys(txn, contactId, keys1));
+
+		// Retrieve the handshake keys
+		Collection<HandshakeKeySet> allKeys =
+				db.getHandshakeKeys(txn, transportId);
+		assertEquals(2, allKeys.size());
+		for (HandshakeKeySet ks : allKeys) {
+			assertEquals(contactId, ks.getContactId());
+			assertNull(ks.getPendingContactId());
+			if (ks.getKeySetId().equals(handshakeKeySetId)) {
+				assertKeysEquals(keys, ks.getKeys());
+			} else {
+				assertEquals(handshakeKeySetId1, ks.getKeySetId());
+				assertKeysEquals(keys1, ks.getKeys());
+			}
+		}
+
+		// Update the handshake keys
+		HandshakeKeys updated =
+				createHandshakeKeys(timePeriod + 1, rootKey, alice);
+		HandshakeKeys updated1 =
+				createHandshakeKeys(timePeriod1 + 1, rootKey1, alice);
+		db.updateHandshakeKeys(txn, new HandshakeKeySet(handshakeKeySetId,
+				contactId, updated));
+		db.updateHandshakeKeys(txn, new HandshakeKeySet(handshakeKeySetId1,
+				contactId, updated1));
+
+		// Retrieve the handshake keys again
+		allKeys = db.getHandshakeKeys(txn, transportId);
+		assertEquals(2, allKeys.size());
+		for (HandshakeKeySet ks : allKeys) {
+			assertEquals(contactId, ks.getContactId());
+			assertNull(ks.getPendingContactId());
+			if (ks.getKeySetId().equals(handshakeKeySetId)) {
+				assertKeysEquals(updated, ks.getKeys());
+			} else {
+				assertEquals(handshakeKeySetId1, ks.getKeySetId());
+				assertKeysEquals(updated1, ks.getKeys());
+			}
+		}
+
+		// Removing the contact should remove the handshake keys
+		db.removeContact(txn, contactId);
+		assertEquals(emptyList(), db.getHandshakeKeys(txn, transportId));
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
+	private void assertKeysEquals(HandshakeKeys expected,
+			HandshakeKeys actual) {
+		assertEquals(expected.getTransportId(), actual.getTransportId());
+		assertEquals(expected.getTimePeriod(), actual.getTimePeriod());
+		assertArrayEquals(expected.getRootKey().getBytes(),
+				actual.getRootKey().getBytes());
+		assertEquals(expected.isAlice(), actual.isAlice());
+		assertKeysEquals(expected.getPreviousIncomingKeys(),
+				actual.getPreviousIncomingKeys());
+		assertKeysEquals(expected.getCurrentIncomingKeys(),
+				actual.getCurrentIncomingKeys());
+		assertKeysEquals(expected.getNextIncomingKeys(),
+				actual.getNextIncomingKeys());
+		assertKeysEquals(expected.getCurrentOutgoingKeys(),
+				actual.getCurrentOutgoingKeys());
+	}
+
+	@Test
+	public void testHandshakeKeysForPendingContact() throws Exception {
+		long timePeriod = 123, timePeriod1 = 234;
+		boolean alice = random.nextBoolean();
+		SecretKey rootKey = getSecretKey();
+		SecretKey rootKey1 = getSecretKey();
+		HandshakeKeys keys = createHandshakeKeys(timePeriod, rootKey, alice);
+		HandshakeKeys keys1 = createHandshakeKeys(timePeriod1, rootKey1, alice);
+
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Initially there should be no handshake keys in the database
+		assertEquals(emptyList(), db.getHandshakeKeys(txn, transportId));
+
+		// Add the pending contact, the transport and the handshake keys
+		db.addPendingContact(txn, pendingContact);
+		db.addTransport(txn, transportId, 123);
+		assertEquals(handshakeKeySetId, db.addHandshakeKeys(txn,
+				pendingContact.getId(), keys));
+		assertEquals(handshakeKeySetId1, db.addHandshakeKeys(txn,
+				pendingContact.getId(), keys1));
+
+		// Retrieve the handshake keys
+		Collection<HandshakeKeySet> allKeys =
+				db.getHandshakeKeys(txn, transportId);
+		assertEquals(2, allKeys.size());
+		for (HandshakeKeySet ks : allKeys) {
+			assertNull(ks.getContactId());
+			assertEquals(pendingContact.getId(), ks.getPendingContactId());
+			if (ks.getKeySetId().equals(handshakeKeySetId)) {
+				assertKeysEquals(keys, ks.getKeys());
+			} else {
+				assertEquals(handshakeKeySetId1, ks.getKeySetId());
+				assertKeysEquals(keys1, ks.getKeys());
+			}
+		}
+
+		// Update the handshake keys
+		HandshakeKeys updated =
+				createHandshakeKeys(timePeriod + 1, rootKey, alice);
+		HandshakeKeys updated1 =
+				createHandshakeKeys(timePeriod1 + 1, rootKey1, alice);
+		db.updateHandshakeKeys(txn, new HandshakeKeySet(handshakeKeySetId,
+				pendingContact.getId(), updated));
+		db.updateHandshakeKeys(txn, new HandshakeKeySet(handshakeKeySetId1,
+				pendingContact.getId(), updated1));
+
+		// Retrieve the handshake keys again
+		allKeys = db.getHandshakeKeys(txn, transportId);
+		assertEquals(2, allKeys.size());
+		for (HandshakeKeySet ks : allKeys) {
+			assertNull(ks.getContactId());
+			assertEquals(pendingContact.getId(), ks.getPendingContactId());
+			if (ks.getKeySetId().equals(handshakeKeySetId)) {
+				assertKeysEquals(updated, ks.getKeys());
+			} else {
+				assertEquals(handshakeKeySetId1, ks.getKeySetId());
+				assertKeysEquals(updated1, ks.getKeys());
+			}
+		}
+
+		// Removing the pending contact should remove the handshake keys
+		db.removePendingContact(txn, pendingContact.getId());
+		assertEquals(emptyList(), db.getHandshakeKeys(txn, transportId));
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
 	@Test
 	public void testIncrementStreamCounter() throws Exception {
-		long rotationPeriod = 123;
-		TransportKeys keys = createTransportKeys(rotationPeriod, true);
+		long timePeriod = 123;
+		TransportKeys keys = createTransportKeys(timePeriod, true);
 		long streamCounter = keys.getCurrentOutgoingKeys().getStreamCounter();
 
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();
 
 		// Add the contact, transport and transport keys
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addTransport(txn, transportId, 123);
 		assertEquals(keySetId, db.addTransportKeys(txn, contactId, keys));
 
 		// Increment the stream counter twice and retrieve the transport keys
 		db.incrementStreamCounter(txn, transportId, keySetId);
 		db.incrementStreamCounter(txn, transportId, keySetId);
-		Collection<KeySet> newKeys = db.getTransportKeys(txn, transportId);
+		Collection<TransportKeySet> newKeys =
+				db.getTransportKeys(txn, transportId);
 		assertEquals(1, newKeys.size());
-		KeySet ks = newKeys.iterator().next();
+		TransportKeySet ks = newKeys.iterator().next();
 		assertEquals(keySetId, ks.getKeySetId());
 		assertEquals(contactId, ks.getContactId());
-		TransportKeys k = ks.getTransportKeys();
+		TransportKeys k = ks.getKeys();
 		assertEquals(transportId, k.getTransportId());
 		OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
-		assertEquals(rotationPeriod, outCurr.getRotationPeriod());
+		assertEquals(timePeriod, outCurr.getTimePeriod());
+		assertEquals(streamCounter + 2, outCurr.getStreamCounter());
+
+		// The rest of the keys should be unaffected
+		assertKeysEquals(keys.getPreviousIncomingKeys(),
+				k.getPreviousIncomingKeys());
+		assertKeysEquals(keys.getCurrentIncomingKeys(),
+				k.getCurrentIncomingKeys());
+		assertKeysEquals(keys.getNextIncomingKeys(), k.getNextIncomingKeys());
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
+	@Test
+	public void testIncrementStreamCounterForHandshakeKeys() throws Exception {
+		long timePeriod = 123;
+		SecretKey rootKey = getSecretKey();
+		boolean alice = random.nextBoolean();
+		HandshakeKeys keys = createHandshakeKeys(timePeriod, rootKey, alice);
+		long streamCounter = keys.getCurrentOutgoingKeys().getStreamCounter();
+
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Add the contact, transport and handshake keys
+		assertEquals(contactId, db.addContact(txn, author, true));
+		db.addTransport(txn, transportId, 123);
+		assertEquals(handshakeKeySetId,
+				db.addHandshakeKeys(txn, contactId, keys));
+
+		// Increment the stream counter twice and retrieve the handshake keys
+		db.incrementStreamCounter(txn, transportId, handshakeKeySetId);
+		db.incrementStreamCounter(txn, transportId, handshakeKeySetId);
+		Collection<HandshakeKeySet> newKeys =
+				db.getHandshakeKeys(txn, transportId);
+		assertEquals(1, newKeys.size());
+		HandshakeKeySet ks = newKeys.iterator().next();
+		assertEquals(handshakeKeySetId, ks.getKeySetId());
+		assertEquals(contactId, ks.getContactId());
+		HandshakeKeys k = ks.getKeys();
+		assertEquals(transportId, k.getTransportId());
+		assertArrayEquals(rootKey.getBytes(), k.getRootKey().getBytes());
+		assertEquals(alice, k.isAlice());
+		OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
+		assertEquals(timePeriod, outCurr.getTimePeriod());
 		assertEquals(streamCounter + 2, outCurr.getStreamCounter());
 
 		// The rest of the keys should be unaffected
@@ -816,8 +978,8 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 	@Test
 	public void testSetReorderingWindow() throws Exception {
 		boolean active = random.nextBoolean();
-		long rotationPeriod = 123;
-		TransportKeys keys = createTransportKeys(rotationPeriod, active);
+		long timePeriod = 123;
+		TransportKeys keys = createTransportKeys(timePeriod, active);
 		long base = keys.getCurrentIncomingKeys().getWindowBase();
 		byte[] bitmap = keys.getCurrentIncomingKeys().getWindowBitmap();
 
@@ -825,25 +987,24 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add the contact, transport and transport keys
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, active));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addTransport(txn, transportId, 123);
 		assertEquals(keySetId, db.addTransportKeys(txn, contactId, keys));
 
 		// Update the reordering window and retrieve the transport keys
 		random.nextBytes(bitmap);
-		db.setReorderingWindow(txn, keySetId, transportId, rotationPeriod,
+		db.setReorderingWindow(txn, keySetId, transportId, timePeriod,
 				base + 1, bitmap);
-		Collection<KeySet> newKeys = db.getTransportKeys(txn, transportId);
+		Collection<TransportKeySet> newKeys =
+				db.getTransportKeys(txn, transportId);
 		assertEquals(1, newKeys.size());
-		KeySet ks = newKeys.iterator().next();
+		TransportKeySet ks = newKeys.iterator().next();
 		assertEquals(keySetId, ks.getKeySetId());
 		assertEquals(contactId, ks.getContactId());
-		TransportKeys k = ks.getTransportKeys();
+		TransportKeys k = ks.getKeys();
 		assertEquals(transportId, k.getTransportId());
 		IncomingKeys inCurr = k.getCurrentIncomingKeys();
-		assertEquals(rotationPeriod, inCurr.getRotationPeriod());
+		assertEquals(timePeriod, inCurr.getTimePeriod());
 		assertEquals(base + 1, inCurr.getWindowBase());
 		assertArrayEquals(bitmap, inCurr.getWindowBitmap());
 
@@ -859,54 +1020,90 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testGetContactsByAuthorId() throws Exception {
+	public void testSetReorderingWindowForHandshakeKeys() throws Exception {
+		long timePeriod = 123;
+		SecretKey rootKey = getSecretKey();
+		boolean alice = random.nextBoolean();
+		HandshakeKeys keys = createHandshakeKeys(timePeriod, rootKey, alice);
+		long base = keys.getCurrentIncomingKeys().getWindowBase();
+		byte[] bitmap = keys.getCurrentIncomingKeys().getWindowBitmap();
+
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();
 
-		// Add a local author - no contacts should be associated
-		db.addLocalAuthor(txn, localAuthor);
+		// Add the contact, transport and handshake keys
+		assertEquals(contactId, db.addContact(txn, author,true));
+		db.addTransport(txn, transportId, 123);
+		assertEquals(handshakeKeySetId,
+				db.addHandshakeKeys(txn, contactId, keys));
 
-		// Add a contact associated with the local author
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		// Update the reordering window and retrieve the handshake keys
+		random.nextBytes(bitmap);
+		db.setReorderingWindow(txn, handshakeKeySetId, transportId, timePeriod,
+				base + 1, bitmap);
+		Collection<HandshakeKeySet> newKeys =
+				db.getHandshakeKeys(txn, transportId);
+		assertEquals(1, newKeys.size());
+		HandshakeKeySet ks = newKeys.iterator().next();
+		assertEquals(handshakeKeySetId, ks.getKeySetId());
+		assertEquals(contactId, ks.getContactId());
+		HandshakeKeys k = ks.getKeys();
+		assertEquals(transportId, k.getTransportId());
+		assertArrayEquals(rootKey.getBytes(), k.getRootKey().getBytes());
+		assertEquals(alice, k.isAlice());
+		IncomingKeys inCurr = k.getCurrentIncomingKeys();
+		assertEquals(timePeriod, inCurr.getTimePeriod());
+		assertEquals(base + 1, inCurr.getWindowBase());
+		assertArrayEquals(bitmap, inCurr.getWindowBitmap());
 
-		// Ensure contact is returned from database by Author ID
-		Collection<Contact> contacts =
-				db.getContactsByAuthorId(txn, author.getId());
-		assertEquals(1, contacts.size());
-		assertEquals(contactId, contacts.iterator().next().getId());
-
-		// Ensure no contacts are returned after contact was deleted
-		db.removeContact(txn, contactId);
-		contacts = db.getContactsByAuthorId(txn, author.getId());
-		assertEquals(0, contacts.size());
+		// The rest of the keys should be unaffected
+		assertKeysEquals(keys.getPreviousIncomingKeys(),
+				k.getPreviousIncomingKeys());
+		assertKeysEquals(keys.getNextIncomingKeys(), k.getNextIncomingKeys());
+		assertKeysEquals(keys.getCurrentOutgoingKeys(),
+				k.getCurrentOutgoingKeys());
 
 		db.commitTransaction(txn);
 		db.close();
 	}
 
 	@Test
-	public void testGetContactsByLocalAuthorId() throws Exception {
+	public void testGetContactByContactId() throws Exception {
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();
 
-		// Add a local author - no contacts should be associated
-		db.addLocalAuthor(txn, localAuthor);
-		Collection<ContactId> contacts =
-				db.getContacts(txn, localAuthor.getId());
-		assertEquals(emptyList(), contacts);
+		// Add a contact
+		assertEquals(contactId, db.addContact(txn, author, true));
 
-		// Add a contact associated with the local author
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
-		contacts = db.getContacts(txn, localAuthor.getId());
-		assertEquals(singletonList(contactId), contacts);
+		// Check the contact is returned
+		Contact c = db.getContact(txn, contactId);
+		assertEquals(contactId, c.getId());
+		assertEquals(author.getId(), c.getAuthor().getId());
+		assertEquals(author.getFormatVersion(),
+				c.getAuthor().getFormatVersion());
+		assertEquals(author.getName(), c.getAuthor().getName());
+		assertArrayEquals(author.getPublicKey(), c.getAuthor().getPublicKey());
 
-		// Remove the local author - the contact should be removed
-		db.removeLocalAuthor(txn, localAuthor.getId());
-		contacts = db.getContacts(txn, localAuthor.getId());
-		assertEquals(emptyList(), contacts);
-		assertFalse(db.containsContact(txn, contactId));
+		db.commitTransaction(txn);
+		db.close();
+	}
+
+	@Test
+	public void testGetContactByAuthorId() throws Exception {
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Add a contact
+		assertEquals(contactId, db.addContact(txn, author, true));
+
+		// Check the contact is returned
+		Contact c = db.getContact(txn, author.getId());
+		assertEquals(contactId, c.getId());
+		assertEquals(author.getId(), c.getAuthor().getId());
+		assertEquals(author.getFormatVersion(),
+				c.getAuthor().getFormatVersion());
+		assertEquals(author.getName(), c.getAuthor().getName());
+		assertArrayEquals(author.getPublicKey(), c.getAuthor().getPublicKey());
 
 		db.commitTransaction(txn);
 		db.close();
@@ -918,9 +1115,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact - initially there should be no offered messages
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		assertEquals(0, db.countOfferedMessages(txn, contactId));
 
 		// Add some offered messages and count them
@@ -1502,9 +1697,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a shared group and a shared message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 		db.addMessage(txn, message, DELIVERED, true, null);
@@ -1601,43 +1794,13 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.close();
 	}
 
-	@Test
-	public void testDifferentLocalAuthorsCanHaveTheSameContact()
-			throws Exception {
-		LocalAuthor localAuthor1 = getLocalAuthor();
-
-		Database<Connection> db = open(false);
-		Connection txn = db.startTransaction();
-
-		// Add two local authors
-		db.addLocalAuthor(txn, localAuthor);
-		db.addLocalAuthor(txn, localAuthor1);
-
-		// Add the same contact for each local author
-		ContactId contactId =
-				db.addContact(txn, author, localAuthor.getId(), true, true);
-		ContactId contactId1 =
-				db.addContact(txn, author, localAuthor1.getId(), true, true);
-
-		// The contacts should be distinct
-		assertNotEquals(contactId, contactId1);
-		assertEquals(2, db.getContacts(txn).size());
-		assertEquals(1, db.getContacts(txn, localAuthor.getId()).size());
-		assertEquals(1, db.getContacts(txn, localAuthor1.getId()).size());
-
-		db.commitTransaction(txn);
-		db.close();
-	}
-
 	@Test
 	public void testDeleteMessage() throws Exception {
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a shared group and a shared message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 		db.addMessage(txn, message, DELIVERED, true, null);
@@ -1683,47 +1846,13 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.close();
 	}
 
-	@Test
-	public void testSetContactActive() throws Exception {
-		Database<Connection> db = open(false);
-		Connection txn = db.startTransaction();
-
-		// Add a contact
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
-
-		// The contact should be active
-		Contact contact = db.getContact(txn, contactId);
-		assertTrue(contact.isActive());
-
-		// Set the contact inactive
-		db.setContactActive(txn, contactId, false);
-
-		// The contact should be inactive
-		contact = db.getContact(txn, contactId);
-		assertFalse(contact.isActive());
-
-		// Set the contact active
-		db.setContactActive(txn, contactId, true);
-
-		// The contact should be active
-		contact = db.getContact(txn, contactId);
-		assertTrue(contact.isActive());
-
-		db.commitTransaction(txn);
-		db.close();
-	}
-
 	@Test
 	public void testSetContactAlias() throws Exception {
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();
 
 		// Add a contact
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 
 		// The contact should have no alias
 		Contact contact = db.getContact(txn, contactId);
@@ -1778,9 +1907,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a group and a message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addMessage(txn, message, UNKNOWN, false, null);
 
@@ -1862,9 +1989,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a shared group and a shared message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 		db.addMessage(txn, message, DELIVERED, true, null);
@@ -1907,9 +2032,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		Connection txn = db.startTransaction();
 
 		// Add a contact, a shared group and a shared message
-		db.addLocalAuthor(txn, localAuthor);
-		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
-				true, true));
+		assertEquals(contactId, db.addContact(txn, author, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
 		db.addMessage(txn, message, DELIVERED, true, null);
@@ -1990,41 +2113,94 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.close();
 	}
 
+	@Test
+	public void testPendingContacts() throws Exception {
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		assertEquals(emptyList(), db.getPendingContacts(txn));
+
+		db.addPendingContact(txn, pendingContact);
+		Collection<PendingContact> pendingContacts =
+				db.getPendingContacts(txn);
+		assertEquals(1, pendingContacts.size());
+		PendingContact retrieved = pendingContacts.iterator().next();
+		assertEquals(pendingContact.getId(), retrieved.getId());
+		assertEquals(pendingContact.getAlias(), retrieved.getAlias());
+		assertEquals(pendingContact.getState(), retrieved.getState());
+		assertEquals(pendingContact.getTimestamp(), retrieved.getTimestamp());
+
+		db.setPendingContactState(txn, pendingContact.getId(), FAILED);
+		pendingContacts = db.getPendingContacts(txn);
+		assertEquals(1, pendingContacts.size());
+		retrieved = pendingContacts.iterator().next();
+		assertEquals(pendingContact.getId(), retrieved.getId());
+		assertEquals(pendingContact.getAlias(), retrieved.getAlias());
+		assertEquals(FAILED, retrieved.getState());
+		assertEquals(pendingContact.getTimestamp(), retrieved.getTimestamp());
+
+		db.removePendingContact(txn, pendingContact.getId());
+		assertEquals(emptyList(), db.getPendingContacts(txn));
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
 	private Database<Connection> open(boolean resume) throws Exception {
 		return open(resume, new TestMessageFactory(), new SystemClock());
 	}
 
 	private Database<Connection> open(boolean resume,
 			MessageFactory messageFactory, Clock clock) throws Exception {
-		Database<Connection> db =
-				createDatabase(new TestDatabaseConfig(testDir, MAX_SIZE),
-						messageFactory, clock);
+		Database<Connection> db = createDatabase(
+				new TestDatabaseConfig(testDir), messageFactory, clock);
 		if (!resume) deleteTestDirectory(testDir);
 		db.open(key, null);
 		return db;
 	}
 
-	private TransportKeys createTransportKeys(long rotationPeriod,
-			boolean active) {
+	private TransportKeys createTransportKeys(long timePeriod, boolean active) {
 		SecretKey inPrevTagKey = getSecretKey();
 		SecretKey inPrevHeaderKey = getSecretKey();
 		IncomingKeys inPrev = new IncomingKeys(inPrevTagKey, inPrevHeaderKey,
-				rotationPeriod - 1, 123, new byte[4]);
+				timePeriod - 1, 123, new byte[4]);
 		SecretKey inCurrTagKey = getSecretKey();
 		SecretKey inCurrHeaderKey = getSecretKey();
 		IncomingKeys inCurr = new IncomingKeys(inCurrTagKey, inCurrHeaderKey,
-				rotationPeriod, 234, new byte[4]);
+				timePeriod, 234, new byte[4]);
 		SecretKey inNextTagKey = getSecretKey();
 		SecretKey inNextHeaderKey = getSecretKey();
 		IncomingKeys inNext = new IncomingKeys(inNextTagKey, inNextHeaderKey,
-				rotationPeriod + 1, 345, new byte[4]);
+				timePeriod + 1, 345, new byte[4]);
 		SecretKey outCurrTagKey = getSecretKey();
 		SecretKey outCurrHeaderKey = getSecretKey();
 		OutgoingKeys outCurr = new OutgoingKeys(outCurrTagKey, outCurrHeaderKey,
-				rotationPeriod, 456, active);
+				timePeriod, 456, active);
 		return new TransportKeys(transportId, inPrev, inCurr, inNext, outCurr);
 	}
 
+	private HandshakeKeys createHandshakeKeys(long timePeriod,
+			SecretKey rootKey, boolean alice) {
+		SecretKey inPrevTagKey = getSecretKey();
+		SecretKey inPrevHeaderKey = getSecretKey();
+		IncomingKeys inPrev = new IncomingKeys(inPrevTagKey, inPrevHeaderKey,
+				timePeriod - 1, 123, new byte[4]);
+		SecretKey inCurrTagKey = getSecretKey();
+		SecretKey inCurrHeaderKey = getSecretKey();
+		IncomingKeys inCurr = new IncomingKeys(inCurrTagKey, inCurrHeaderKey,
+				timePeriod, 234, new byte[4]);
+		SecretKey inNextTagKey = getSecretKey();
+		SecretKey inNextHeaderKey = getSecretKey();
+		IncomingKeys inNext = new IncomingKeys(inNextTagKey, inNextHeaderKey,
+				timePeriod + 1, 345, new byte[4]);
+		SecretKey outCurrTagKey = getSecretKey();
+		SecretKey outCurrHeaderKey = getSecretKey();
+		OutgoingKeys outCurr = new OutgoingKeys(outCurrTagKey, outCurrHeaderKey,
+				timePeriod, 456, true);
+		return new HandshakeKeys(transportId, inPrev, inCurr, inNext, outCurr,
+				rootKey, alice);
+	}
+
 	@After
 	public void tearDown() {
 		deleteTestDirectory(testDir);

bramble-core/src/test/java/org/briarproject/bramble/db/SingleDatabasePerformanceTest.java

@@ -45,8 +45,8 @@ public abstract class SingleDatabasePerformanceTest
 
 	private Database<Connection> openDatabase() throws DbException {
 		Database<Connection> db = createDatabase(
-				new TestDatabaseConfig(testDir, MAX_SIZE),
-				new TestMessageFactory(), new SystemClock());
+				new TestDatabaseConfig(testDir), new TestMessageFactory(),
+				new SystemClock());
 		db.open(databaseKey, null);
 		return db;
 	}

bramble-core/src/test/java/org/briarproject/bramble/keyagreement/KeyAgreementProtocolTest.java

@@ -17,7 +17,7 @@ import org.junit.Rule;
 import org.junit.Test;
 
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.COMMIT_LENGTH;
-import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.MASTER_SECRET_LABEL;
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.MASTER_KEY_LABEL;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.SHARED_SECRET_LABEL;
 import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
@@ -74,7 +74,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 		Payload ourPayload = new Payload(aliceCommit, null);
 		KeyPair ourKeyPair = new KeyPair(ourPubKey, null);
 		SecretKey sharedSecret = getSecretKey();
-		SecretKey masterSecret = getSecretKey();
+		SecretKey masterKey = getSecretKey();
 
 		KeyAgreementProtocol protocol = new KeyAgreementProtocol(callbacks,
 				crypto, keyAgreementCrypto, payloadEncoder, transport,
@@ -134,13 +134,13 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 					true, false);
 			will(returnValue(bobConfirm));
 
-			// Alice computes master secret
-			oneOf(crypto).deriveKey(MASTER_SECRET_LABEL, sharedSecret);
-			will(returnValue(masterSecret));
+			// Alice derives master key
+			oneOf(crypto).deriveKey(MASTER_KEY_LABEL, sharedSecret);
+			will(returnValue(masterKey));
 		}});
 
 		// execute
-		assertThat(masterSecret, is(equalTo(protocol.perform())));
+		assertThat(masterKey, is(equalTo(protocol.perform())));
 	}
 
 	@Test
@@ -150,7 +150,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 		Payload ourPayload = new Payload(bobCommit, null);
 		KeyPair ourKeyPair = new KeyPair(ourPubKey, null);
 		SecretKey sharedSecret = getSecretKey();
-		SecretKey masterSecret = getSecretKey();
+		SecretKey masterKey = getSecretKey();
 
 		KeyAgreementProtocol protocol = new KeyAgreementProtocol(callbacks,
 				crypto, keyAgreementCrypto, payloadEncoder, transport,
@@ -209,13 +209,13 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			will(returnValue(bobConfirm));
 			oneOf(transport).sendConfirm(bobConfirm);
 
-			// Bob computes master secret
-			oneOf(crypto).deriveKey(MASTER_SECRET_LABEL, sharedSecret);
-			will(returnValue(masterSecret));
+			// Bob derives master key
+			oneOf(crypto).deriveKey(MASTER_KEY_LABEL, sharedSecret);
+			will(returnValue(masterKey));
 		}});
 
 		// execute
-		assertThat(masterSecret, is(equalTo(protocol.perform())));
+		assertThat(masterKey, is(equalTo(protocol.perform())));
 	}
 
 	@Test(expected = AbortException.class)
@@ -373,8 +373,8 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 			// Alice aborts
 			oneOf(transport).sendAbort(false);
 
-			// Alice never computes master secret
-			never(crypto).deriveKey(MASTER_SECRET_LABEL, sharedSecret);
+			// Alice never derives master key
+			never(crypto).deriveKey(MASTER_KEY_LABEL, sharedSecret);
 		}});
 
 		// execute

bramble-core/src/test/java/org/briarproject/bramble/plugin/ConnectionRegistryImplTest.java

@@ -17,6 +17,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.NoSuchElementException;
 
+import static org.briarproject.bramble.test.TestUtils.getContactId;
 import static org.briarproject.bramble.test.TestUtils.getTransportId;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
@@ -28,8 +29,8 @@ public class ConnectionRegistryImplTest extends BrambleTestCase {
 	private final TransportId transportId, transportId1;
 
 	public ConnectionRegistryImplTest() {
-		contactId = new ContactId(1);
-		contactId1 = new ContactId(2);
+		contactId = getContactId();
+		contactId1 = getContactId();
 		transportId = getTransportId();
 		transportId1 = getTransportId();
 	}

bramble-core/src/test/java/org/briarproject/bramble/plugin/PollerTest.java

@@ -1,7 +1,7 @@
 package org.briarproject.bramble.plugin;
 
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.event.ContactStatusChangedEvent;
+import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
 import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.plugin.Plugin;
@@ -36,6 +36,7 @@ import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static org.briarproject.bramble.test.TestUtils.getContactId;
 import static org.briarproject.bramble.test.TestUtils.getTransportId;
 
 public class PollerTest extends BrambleMockTestCase {
@@ -56,7 +57,7 @@ public class PollerTest extends BrambleMockTestCase {
 
 	private final Executor ioExecutor = new ImmediateExecutor();
 	private final TransportId transportId = getTransportId();
-	private final ContactId contactId = new ContactId(234);
+	private final ContactId contactId = getContactId();
 	private final TransportProperties properties = new TransportProperties();
 	private final int pollingInterval = 60 * 1000;
 	private final long now = System.currentTimeMillis();
@@ -67,7 +68,7 @@ public class PollerTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testConnectOnContactStatusChanged() throws Exception {
+	public void testConnectOnContactAdded() throws Exception {
 		// Two simplex plugins: one supports polling, the other doesn't
 		SimplexPlugin simplexPlugin = context.mock(SimplexPlugin.class);
 		SimplexPlugin simplexPlugin1 =
@@ -143,7 +144,7 @@ public class PollerTest extends BrambleMockTestCase {
 				connectionRegistry, pluginManager, transportPropertyManager,
 				random, clock);
 
-		p.eventOccurred(new ContactStatusChangedEvent(contactId, true));
+		p.eventOccurred(new ContactAddedEvent(contactId));
 	}
 
 	@Test

bramble-core/src/test/java/org/briarproject/bramble/properties/TransportPropertyManagerImplTest.java

@@ -11,6 +11,7 @@ import org.briarproject.bramble.api.data.MetadataParser;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
@@ -36,12 +37,11 @@ import static java.util.Collections.singletonMap;
 import static org.briarproject.bramble.api.properties.TransportPropertyManager.CLIENT_ID;
 import static org.briarproject.bramble.api.properties.TransportPropertyManager.MAJOR_VERSION;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
-import static org.briarproject.bramble.test.TestUtils.getAuthor;
+import static org.briarproject.bramble.test.TestUtils.getContact;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getLocalAuthor;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
-import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 
@@ -49,6 +49,8 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 
 	private final DatabaseComponent db = context.mock(DatabaseComponent.class);
 	private final ClientHelper clientHelper = context.mock(ClientHelper.class);
+	private final IdentityManager identityManager =
+			context.mock(IdentityManager.class);
 	private final ClientVersioningManager clientVersioningManager =
 			context.mock(ClientVersioningManager.class);
 	private final MetadataParser metadataParser =
@@ -69,8 +71,6 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 	);
 	private final TransportProperties fooProperties, barProperties;
 
-	private int nextContactId = 0;
-
 	public TransportPropertyManagerImplTest() throws Exception {
 		fooProperties = new TransportProperties();
 		for (String key : fooPropertiesDict.keySet())
@@ -87,24 +87,26 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(localGroup));
 		}});
 		return new TransportPropertyManagerImpl(db, clientHelper,
-				clientVersioningManager, metadataParser, contactGroupFactory,
-				clock);
+				identityManager, clientVersioningManager, metadataParser,
+				contactGroupFactory, clock);
 	}
 
 	@Test
 	public void testCreatesGroupsAtStartup() throws Exception {
 		Transaction txn = new Transaction(null, false);
-		Contact contact = getContact(true);
+		Contact contact = getContact();
 		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
 
 		context.checking(new Expectations() {{
 			oneOf(db).containsGroup(txn, localGroup.getId());
 			will(returnValue(false));
 			oneOf(db).addGroup(txn, localGroup);
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(db).getContacts(txn);
 			will(returnValue(singletonList(contact)));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			oneOf(db).addGroup(txn, contactGroup);
 			oneOf(clientVersioningManager).getClientVisibility(txn,
@@ -141,13 +143,15 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testCreatesContactGroupWhenAddingContact() throws Exception {
 		Transaction txn = new Transaction(null, false);
-		Contact contact = getContact(true);
+		Contact contact = getContact();
 		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
 
 		context.checking(new Expectations() {{
 			// Create the group and share it with the contact
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			oneOf(db).addGroup(txn, contactGroup);
 			oneOf(clientVersioningManager).getClientVisibility(txn,
@@ -170,12 +174,14 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testRemovesGroupWhenRemovingContact() throws Exception {
 		Transaction txn = new Transaction(null, false);
-		Contact contact = getContact(true);
+		Contact contact = getContact();
 		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
 
 		context.checking(new Expectations() {{
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			oneOf(db).removeGroup(txn, contactGroup);
 		}});
@@ -302,7 +308,7 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testStoresRemotePropertiesWithVersion0() throws Exception {
-		Contact contact = getContact(true);
+		Contact contact = getContact();
 		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
 		Transaction txn = new Transaction(null, false);
 		Map<TransportId, TransportProperties> properties =
@@ -313,8 +319,10 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		context.checking(new Expectations() {{
 			oneOf(db).getContact(txn, contact.getId());
 			will(returnValue(contact));
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 		}});
 		expectStoreMessage(txn, contactGroup.getId(), "foo", fooPropertiesDict,
@@ -406,31 +414,30 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 	public void testReturnsRemotePropertiesOrEmptyProperties()
 			throws Exception {
 		Transaction txn = new Transaction(null, true);
-		Contact contact1 = getContact(false);
-		Contact contact2 = getContact(true);
-		Contact contact3 = getContact(true);
-		List<Contact> contacts = asList(contact1, contact2, contact3);
+		Contact contact1 = getContact();
+		Contact contact2 = getContact();
+		List<Contact> contacts = asList(contact1, contact2);
+		Group contactGroup1 = getGroup(CLIENT_ID, MAJOR_VERSION);
 		Group contactGroup2 = getGroup(CLIENT_ID, MAJOR_VERSION);
-		Group contactGroup3 = getGroup(CLIENT_ID, MAJOR_VERSION);
-		Map<MessageId, BdfDictionary> messageMetadata3 =
+		Map<MessageId, BdfDictionary> messageMetadata2 =
 				new LinkedHashMap<>();
 		// A remote update for another transport should be ignored
 		MessageId barUpdateId = new MessageId(getRandomId());
-		messageMetadata3.put(barUpdateId, BdfDictionary.of(
+		messageMetadata2.put(barUpdateId, BdfDictionary.of(
 				new BdfEntry("transportId", "bar"),
 				new BdfEntry("version", 1),
 				new BdfEntry("local", false)
 		));
 		// A local update for the right transport should be ignored
 		MessageId localUpdateId = new MessageId(getRandomId());
-		messageMetadata3.put(localUpdateId, BdfDictionary.of(
+		messageMetadata2.put(localUpdateId, BdfDictionary.of(
 				new BdfEntry("transportId", "foo"),
 				new BdfEntry("version", 1),
 				new BdfEntry("local", true)
 		));
 		// A remote update for the right transport should be returned
 		MessageId fooUpdateId = new MessageId(getRandomId());
-		messageMetadata3.put(fooUpdateId, BdfDictionary.of(
+		messageMetadata2.put(fooUpdateId, BdfDictionary.of(
 				new BdfEntry("transportId", "foo"),
 				new BdfEntry("version", 1),
 				new BdfEntry("local", false)
@@ -439,23 +446,24 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 
 		context.checking(new DbExpectations() {{
 			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(db).getContacts(txn);
 			will(returnValue(contacts));
-			// First contact: skipped because not active
-			// Second contact: no updates
+			// First contact: no updates
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact2);
+					MAJOR_VERSION, contact1, localAuthor.getId());
+			will(returnValue(contactGroup1));
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup1.getId());
+			will(returnValue(Collections.emptyMap()));
+			// Second contact: returns an update
+			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
+					MAJOR_VERSION, contact2, localAuthor.getId());
 			will(returnValue(contactGroup2));
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup2.getId());
-			will(returnValue(Collections.emptyMap()));
-			// Third contact: returns an update
-			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact3);
-			will(returnValue(contactGroup3));
-			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
-					contactGroup3.getId());
-			will(returnValue(messageMetadata3));
+			will(returnValue(messageMetadata2));
 			oneOf(clientHelper).getMessageAsList(txn, fooUpdateId);
 			will(returnValue(fooUpdate));
 			oneOf(clientHelper).parseAndValidateTransportProperties(
@@ -466,10 +474,9 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		TransportPropertyManagerImpl t = createInstance();
 		Map<ContactId, TransportProperties> properties =
 				t.getRemoteProperties(new TransportId("foo"));
-		assertEquals(3, properties.size());
+		assertEquals(2, properties.size());
 		assertEquals(0, properties.get(contact1.getId()).size());
-		assertEquals(0, properties.get(contact2.getId()).size());
-		assertEquals(fooProperties, properties.get(contact3.getId()));
+		assertEquals(fooProperties, properties.get(contact2.getId()));
 	}
 
 	@Test
@@ -506,7 +513,7 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testMergingNewPropertiesCreatesUpdate() throws Exception {
 		Transaction txn = new Transaction(null, false);
-		Contact contact = getContact(true);
+		Contact contact = getContact();
 		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
 
 		context.checking(new DbExpectations() {{
@@ -519,10 +526,12 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			expectStoreMessage(txn, localGroup.getId(), "foo",
 					fooPropertiesDict, 1, true, false);
 			// Store the new properties in each contact's group, version 1
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(db).getContacts(txn);
 			will(returnValue(singletonList(contact)));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup.getId());
@@ -538,7 +547,7 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testMergingUpdatedPropertiesCreatesUpdate() throws Exception {
 		Transaction txn = new Transaction(null, false);
-		Contact contact = getContact(true);
+		Contact contact = getContact();
 		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
 		BdfDictionary oldMetadata = BdfDictionary.of(
 				new BdfEntry("transportId", "foo"),
@@ -575,10 +584,12 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			// Delete the previous update
 			oneOf(db).removeMessage(txn, localGroupUpdateId);
 			// Store the merged properties in each contact's group, version 2
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(db).getContacts(txn);
 			will(returnValue(singletonList(contact)));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup.getId());
@@ -593,12 +604,6 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		t.mergeLocalProperties(new TransportId("foo"), fooProperties);
 	}
 
-	private Contact getContact(boolean active) {
-		ContactId c = new ContactId(nextContactId++);
-		return new Contact(c, getAuthor(), localAuthor.getId(),
-				getRandomString(5), true, active);
-	}
-
 	private void expectGetLocalProperties(Transaction txn) throws Exception {
 		Map<MessageId, BdfDictionary> messageMetadata = new LinkedHashMap<>();
 		// The latest update for transport "foo" should be returned

bramble-core/src/test/java/org/briarproject/bramble/sync/SimplexOutgoingSessionTest.java

@@ -19,6 +19,7 @@ import java.util.concurrent.Executor;
 
 import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
+import static org.briarproject.bramble.test.TestUtils.getContactId;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 
@@ -33,7 +34,7 @@ public class SimplexOutgoingSessionTest extends BrambleMockTestCase {
 			context.mock(SyncRecordWriter.class);
 
 	private final Executor dbExecutor = new ImmediateExecutor();
-	private final ContactId contactId = new ContactId(234);
+	private final ContactId contactId = getContactId();
 	private final Message message = getMessage(new GroupId(getRandomId()));
 	private final MessageId messageId = message.getId();
 

bramble-core/src/test/java/org/briarproject/bramble/sync/SyncIntegrationTest.java

@@ -22,7 +22,6 @@ import org.briarproject.bramble.api.transport.StreamReaderFactory;
 import org.briarproject.bramble.api.transport.StreamWriter;
 import org.briarproject.bramble.api.transport.StreamWriterFactory;
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestUtils;
 import org.junit.Test;
 
 import java.io.ByteArrayInputStream;
@@ -37,6 +36,8 @@ import static org.briarproject.bramble.api.sync.SyncConstants.MAX_GROUP_DESCRIPT
 import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
 import static org.briarproject.bramble.test.TestUtils.getClientId;
+import static org.briarproject.bramble.test.TestUtils.getContactId;
+import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.briarproject.bramble.test.TestUtils.getTransportId;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
@@ -73,11 +74,11 @@ public class SyncIntegrationTest extends BrambleTestCase {
 				DaggerSyncIntegrationTestComponent.builder().build();
 		component.inject(this);
 
-		contactId = new ContactId(234);
+		contactId = getContactId();
 		transportId = getTransportId();
 		// Create the transport keys
-		tagKey = TestUtils.getSecretKey();
-		headerKey = TestUtils.getSecretKey();
+		tagKey = getSecretKey();
+		headerKey = getSecretKey();
 		streamNumber = 123;
 		// Create a group
 		ClientId clientId = getClientId();

bramble-core/src/test/java/org/briarproject/bramble/sync/validation/ValidationManagerImplTest.java

@@ -37,6 +37,7 @@ import static org.briarproject.bramble.api.sync.validation.MessageState.INVALID;
 import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
 import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
 import static org.briarproject.bramble.test.TestUtils.getClientId;
+import static org.briarproject.bramble.test.TestUtils.getContactId;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
@@ -64,7 +65,7 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 
 	private final Metadata metadata = new Metadata();
 	private final MessageContext validResult = new MessageContext(metadata);
-	private final ContactId contactId = new ContactId(234);
+	private final ContactId contactId = getContactId();
 	private final MessageContext validResultWithDependencies =
 			new MessageContext(metadata, singletonList(messageId1));
 

bramble-core/src/test/java/org/briarproject/bramble/test/TestDatabaseConfig.java

@@ -9,12 +9,10 @@ import java.io.File;
 public class TestDatabaseConfig implements DatabaseConfig {
 
 	private final File dbDir, keyDir;
-	private final long maxSize;
 
-	public TestDatabaseConfig(File testDir, long maxSize) {
+	public TestDatabaseConfig(File testDir) {
 		dbDir = new File(testDir, "db");
 		keyDir = new File(testDir, "key");
-		this.maxSize = maxSize;
 	}
 
 	@Override
@@ -26,9 +24,4 @@ public class TestDatabaseConfig implements DatabaseConfig {
 	public File getDatabaseKeyDirectory() {
 		return keyDir;
 	}
-
-	@Override
-	public long getMaxSize() {
-		return maxSize;
-	}
 }

bramble-core/src/test/java/org/briarproject/bramble/test/TestDatabaseModule.java

@@ -21,7 +21,7 @@ public class TestDatabaseModule {
 	}
 
 	public TestDatabaseModule(File dir) {
-		config = new TestDatabaseConfig(dir, Long.MAX_VALUE);
+		config = new TestDatabaseConfig(dir);
 	}
 
 	@Provides

bramble-core/src/test/java/org/briarproject/bramble/transport/KeyManagerImplTest.java

@@ -1,19 +1,15 @@
 package org.briarproject.bramble.transport;
 
-import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
-import org.briarproject.bramble.api.contact.event.ContactStatusChangedEvent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.plugin.PluginConfig;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.DbExpectations;
 import org.jmock.Expectations;
@@ -21,7 +17,6 @@ import org.jmock.lib.concurrent.DeterministicExecutor;
 import org.junit.Before;
 import org.junit.Test;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Map;
 import java.util.Random;
@@ -29,12 +24,10 @@ import java.util.Random;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
-import static org.briarproject.bramble.test.TestUtils.getAuthor;
+import static org.briarproject.bramble.test.TestUtils.getContactId;
 import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
-import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.briarproject.bramble.test.TestUtils.getTransportId;
-import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 
@@ -49,14 +42,12 @@ public class KeyManagerImplTest extends BrambleMockTestCase {
 
 	private final DeterministicExecutor executor = new DeterministicExecutor();
 	private final Transaction txn = new Transaction(null, false);
-	private final ContactId contactId = new ContactId(123);
-	private final ContactId inactiveContactId = new ContactId(234);
-	private final KeySetId keySetId = new KeySetId(345);
+	private final ContactId contactId = getContactId();
+	private final TransportKeySetId keySetId = new TransportKeySetId(345);
 	private final TransportId transportId = getTransportId();
 	private final TransportId unknownTransportId = getTransportId();
-	private final StreamContext streamContext =
-			new StreamContext(contactId, transportId, getSecretKey(),
-					getSecretKey(), 1);
+	private final StreamContext streamContext = new StreamContext(contactId,
+			transportId, getSecretKey(), getSecretKey(), 1);
 	private final byte[] tag = getRandomBytes(TAG_LENGTH);
 	private final Random random = new Random();
 
@@ -66,13 +57,6 @@ public class KeyManagerImplTest extends BrambleMockTestCase {
 	@Before
 	public void testStartService() throws Exception {
 		Transaction txn = new Transaction(null, false);
-		Author remoteAuthor = getAuthor();
-		AuthorId localAuthorId = new AuthorId(getRandomId());
-		Collection<Contact> contacts = new ArrayList<>();
-		contacts.add(new Contact(contactId, remoteAuthor, localAuthorId,
-				getRandomString(5), true, true));
-		contacts.add(new Contact(inactiveContactId, remoteAuthor, localAuthorId,
-				getRandomString(5), true, false));
 		SimplexPluginFactory pluginFactory =
 				context.mock(SimplexPluginFactory.class);
 		Collection<SimplexPluginFactory> factories =
@@ -92,8 +76,6 @@ public class KeyManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(transportKeyManager));
 			oneOf(pluginConfig).getDuplexFactories();
 			oneOf(db).transaction(with(false), withDbRunnable(txn));
-			oneOf(db).getContacts(txn);
-			will(returnValue(contacts));
 			oneOf(transportKeyManager).start(txn);
 		}});
 
@@ -113,16 +95,11 @@ public class KeyManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(keySetId));
 		}});
 
-		Map<TransportId, KeySetId> ids = keyManager.addContact(txn, contactId,
-				secretKey, timestamp, alice, active);
+		Map<TransportId, TransportKeySetId> ids = keyManager.addContact(txn,
+				contactId, secretKey, timestamp, alice, active);
 		assertEquals(singletonMap(transportId, keySetId), ids);
 	}
 
-	@Test
-	public void testGetStreamContextForInactiveContact() throws Exception {
-		assertNull(keyManager.getStreamContext(inactiveContactId, transportId));
-	}
-
 	@Test
 	public void testGetStreamContextForUnknownTransport() throws Exception {
 		assertNull(keyManager.getStreamContext(contactId, unknownTransportId));
@@ -161,7 +138,7 @@ public class KeyManagerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testContactRemovedEvent() throws Exception {
+	public void testContactRemovedEvent() {
 		ContactRemovedEvent event = new ContactRemovedEvent(contactId);
 
 		context.checking(new Expectations() {{
@@ -170,23 +147,5 @@ public class KeyManagerImplTest extends BrambleMockTestCase {
 
 		keyManager.eventOccurred(event);
 		executor.runUntilIdle();
-		assertNull(keyManager.getStreamContext(contactId, transportId));
-	}
-
-	@Test
-	public void testContactStatusChangedEvent() throws Exception {
-		ContactStatusChangedEvent event =
-				new ContactStatusChangedEvent(inactiveContactId, true);
-
-		context.checking(new DbExpectations() {{
-			oneOf(db).transactionWithNullableResult(with(false),
-					withNullableDbCallable(txn));
-			oneOf(transportKeyManager).getStreamContext(txn, inactiveContactId);
-			will(returnValue(streamContext));
-		}});
-
-		keyManager.eventOccurred(event);
-		assertEquals(streamContext,
-				keyManager.getStreamContext(inactiveContactId, transportId));
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/transport/TransportKeyManagerImplTest.java

@@ -8,15 +8,14 @@ import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.transport.IncomingKeys;
-import org.briarproject.bramble.api.transport.KeySet;
-import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
 import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.TransportKeySet;
+import org.briarproject.bramble.api.transport.TransportKeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.DbExpectations;
 import org.briarproject.bramble.test.RunAction;
-import org.briarproject.bramble.test.TestUtils;
 import org.hamcrest.Description;
 import org.jmock.Expectations;
 import org.jmock.api.Action;
@@ -37,6 +36,8 @@ import static org.briarproject.bramble.api.transport.TransportConstants.MAX_CLOC
 import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.api.transport.TransportConstants.REORDERING_WINDOW_SIZE;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
+import static org.briarproject.bramble.test.TestUtils.getContactId;
+import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.briarproject.bramble.test.TestUtils.getTransportId;
 import static org.briarproject.bramble.util.ByteUtils.MAX_32_BIT_UNSIGNED;
 import static org.junit.Assert.assertEquals;
@@ -57,31 +58,31 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 
 	private final TransportId transportId = getTransportId();
 	private final long maxLatency = 30 * 1000; // 30 seconds
-	private final long rotationPeriodLength = maxLatency + MAX_CLOCK_DIFFERENCE;
-	private final ContactId contactId = new ContactId(123);
-	private final ContactId contactId1 = new ContactId(234);
-	private final KeySetId keySetId = new KeySetId(345);
-	private final KeySetId keySetId1 = new KeySetId(456);
-	private final SecretKey tagKey = TestUtils.getSecretKey();
-	private final SecretKey headerKey = TestUtils.getSecretKey();
-	private final SecretKey masterKey = TestUtils.getSecretKey();
+	private final long timePeriodLength = maxLatency + MAX_CLOCK_DIFFERENCE;
+	private final ContactId contactId = getContactId();
+	private final ContactId contactId1 = getContactId();
+	private final TransportKeySetId keySetId = new TransportKeySetId(345);
+	private final TransportKeySetId keySetId1 = new TransportKeySetId(456);
+	private final SecretKey tagKey = getSecretKey();
+	private final SecretKey headerKey = getSecretKey();
+	private final SecretKey rootKey = getSecretKey();
 	private final Random random = new Random();
 
 	@Test
 	public void testKeysAreRotatedAtStartup() throws Exception {
 		TransportKeys shouldRotate = createTransportKeys(900, 0, true);
 		TransportKeys shouldNotRotate = createTransportKeys(1000, 0, true);
-		Collection<KeySet> loaded = asList(
-				new KeySet(keySetId, contactId, shouldRotate),
-				new KeySet(keySetId1, contactId1, shouldNotRotate)
+		Collection<TransportKeySet> loaded = asList(
+				new TransportKeySet(keySetId, contactId, shouldRotate),
+				new TransportKeySet(keySetId1, contactId1, shouldNotRotate)
 		);
 		TransportKeys rotated = createTransportKeys(1000, 0, true);
 		Transaction txn = new Transaction(null, false);
 
 		context.checking(new Expectations() {{
-			// Get the current time (1 ms after start of rotation period 1000)
+			// Get the current time (1 ms after start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000 + 1));
+			will(returnValue(timePeriodLength * 1000 + 1));
 			// Load the transport keys
 			oneOf(db).getTransportKeys(txn, transportId);
 			will(returnValue(loaded));
@@ -98,11 +99,11 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 				will(new EncodeTagAction());
 			}
 			// Save the keys that were rotated
-			oneOf(db).updateTransportKeys(txn,
-					singletonList(new KeySet(keySetId, contactId, rotated)));
-			// Schedule key rotation at the start of the next rotation period
+			oneOf(db).updateTransportKeys(txn, singletonList(
+					new TransportKeySet(keySetId, contactId, rotated)));
+			// Schedule key rotation at the start of the next time period
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(rotationPeriodLength - 1), with(MILLISECONDS));
+					with(timePeriodLength - 1), with(MILLISECONDS));
 		}});
 
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
@@ -120,12 +121,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		Transaction txn = new Transaction(null, false);
 
 		context.checking(new Expectations() {{
-			oneOf(transportCrypto).deriveTransportKeys(transportId, masterKey,
+			oneOf(transportCrypto).deriveTransportKeys(transportId, rootKey,
 					999, alice, true);
 			will(returnValue(transportKeys));
-			// Get the current time (1 ms after start of rotation period 1000)
+			// Get the current time (1 ms after start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000 + 1));
+			will(returnValue(timePeriodLength * 1000 + 1));
 			// Rotate the transport keys
 			oneOf(transportCrypto).rotateTransportKeys(transportKeys, 1000);
 			will(returnValue(rotated));
@@ -144,10 +145,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is 1 ms before the start of rotation period 1000
-		long timestamp = rotationPeriodLength * 1000 - 1;
+		// The timestamp is 1 ms before the start of time period 1000
+		long timestamp = timePeriodLength * 1000 - 1;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, true));
+				rootKey, timestamp, alice, true));
 		assertTrue(transportKeyManager.canSendOutgoingStreams(contactId));
 	}
 
@@ -177,10 +178,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		// The timestamp is at the start of time period 1000
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, true));
+				rootKey, timestamp, alice, true));
 		assertFalse(transportKeyManager.canSendOutgoingStreams(contactId));
 		assertNull(transportKeyManager.getStreamContext(txn, contactId));
 	}
@@ -203,10 +204,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		// The timestamp is at the start of time period 1000
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, true));
+				rootKey, timestamp, alice, true));
 		// The first request should return a stream context
 		assertTrue(transportKeyManager.canSendOutgoingStreams(contactId));
 		StreamContext ctx = transportKeyManager.getStreamContext(txn,
@@ -235,10 +236,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		// The timestamp is at the start of time period 1000
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, active));
+				rootKey, timestamp, alice, active));
 		assertEquals(active,
 				transportKeyManager.canSendOutgoingStreams(contactId));
 		// The tag should not be recognised
@@ -256,12 +257,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		List<byte[]> tags = new ArrayList<>();
 
 		context.checking(new Expectations() {{
-			oneOf(transportCrypto).deriveTransportKeys(transportId, masterKey,
+			oneOf(transportCrypto).deriveTransportKeys(transportId, rootKey,
 					1000, alice, true);
 			will(returnValue(transportKeys));
-			// Get the current time (the start of rotation period 1000)
+			// Get the current time (the start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000));
+			will(returnValue(timePeriodLength * 1000));
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(transportCrypto).encodeTag(
@@ -280,7 +281,7 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 					with(tagKey), with(PROTOCOL_VERSION),
 					with((long) REORDERING_WINDOW_SIZE));
 			will(new EncodeTagAction(tags));
-			// Save the reordering window (previous rotation period, base 1)
+			// Save the reordering window (previous time period, base 1)
 			oneOf(db).setReorderingWindow(txn, keySetId, transportId, 999,
 					1, new byte[REORDERING_WINDOW_SIZE / 8]);
 		}});
@@ -288,12 +289,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		// The timestamp is at the start of time period 1000
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, true));
+				rootKey, timestamp, alice, true));
 		assertTrue(transportKeyManager.canSendOutgoingStreams(contactId));
-		// Use the first tag (previous rotation period, stream number 0)
+		// Use the first tag (previous time period, stream number 0)
 		assertEquals(REORDERING_WINDOW_SIZE * 3, tags.size());
 		byte[] tag = tags.get(0);
 		// The first request should return a stream context
@@ -313,16 +314,16 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testKeysAreRotatedToCurrentPeriod() throws Exception {
 		TransportKeys transportKeys = createTransportKeys(1000, 0, true);
-		Collection<KeySet> loaded =
-				singletonList(new KeySet(keySetId, contactId, transportKeys));
+		Collection<TransportKeySet> loaded = singletonList(
+				new TransportKeySet(keySetId, contactId, transportKeys));
 		TransportKeys rotated = createTransportKeys(1001, 0, true);
 		Transaction txn = new Transaction(null, false);
 		Transaction txn1 = new Transaction(null, false);
 
 		context.checking(new DbExpectations() {{
-			// Get the current time (the start of rotation period 1000)
+			// Get the current time (the start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000));
+			will(returnValue(timePeriodLength * 1000));
 			// Load the transport keys
 			oneOf(db).getTransportKeys(txn, transportId);
 			will(returnValue(loaded));
@@ -336,17 +337,17 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 						with(PROTOCOL_VERSION), with(i));
 				will(new EncodeTagAction());
 			}
-			// Schedule key rotation at the start of the next rotation period
+			// Schedule key rotation at the start of the next time period
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(rotationPeriodLength), with(MILLISECONDS));
+					with(timePeriodLength), with(MILLISECONDS));
 			will(new RunAction());
 			oneOf(dbExecutor).execute(with(any(Runnable.class)));
 			will(new RunAction());
 			// Start a transaction for key rotation
 			oneOf(db).transaction(with(false), withDbRunnable(txn1));
-			// Get the current time (the start of rotation period 1001)
+			// Get the current time (the start of time period 1001)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1001));
+			will(returnValue(timePeriodLength * 1001));
 			// Rotate the transport keys
 			oneOf(transportCrypto).rotateTransportKeys(
 					with(any(TransportKeys.class)), with(1001L));
@@ -359,11 +360,11 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 				will(new EncodeTagAction());
 			}
 			// Save the keys that were rotated
-			oneOf(db).updateTransportKeys(txn1,
-					singletonList(new KeySet(keySetId, contactId, rotated)));
-			// Schedule key rotation at the start of the next rotation period
+			oneOf(db).updateTransportKeys(txn1, singletonList(
+					new TransportKeySet(keySetId, contactId, rotated)));
+			// Schedule key rotation at the start of the next time period
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(rotationPeriodLength), with(MILLISECONDS));
+					with(timePeriodLength), with(MILLISECONDS));
 		}});
 
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
@@ -391,10 +392,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		// The timestamp is at the start of time period 1000
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, false));
+				rootKey, timestamp, alice, false));
 		// The keys are inactive so no stream context should be returned
 		assertFalse(transportKeyManager.canSendOutgoingStreams(contactId));
 		assertNull(transportKeyManager.getStreamContext(txn, contactId));
@@ -421,12 +422,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		List<byte[]> tags = new ArrayList<>();
 
 		context.checking(new Expectations() {{
-			oneOf(transportCrypto).deriveTransportKeys(transportId, masterKey,
+			oneOf(transportCrypto).deriveTransportKeys(transportId, rootKey,
 					1000, alice, false);
 			will(returnValue(transportKeys));
-			// Get the current time (the start of rotation period 1000)
+			// Get the current time (the start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000));
+			will(returnValue(timePeriodLength * 1000));
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(transportCrypto).encodeTag(
@@ -445,7 +446,7 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 					with(tagKey), with(PROTOCOL_VERSION),
 					with((long) REORDERING_WINDOW_SIZE));
 			will(new EncodeTagAction(tags));
-			// Save the reordering window (previous rotation period, base 1)
+			// Save the reordering window (previous time period, base 1)
 			oneOf(db).setReorderingWindow(txn, keySetId, transportId, 999,
 					1, new byte[REORDERING_WINDOW_SIZE / 8]);
 			// Activate the keys
@@ -457,10 +458,10 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		TransportKeyManager transportKeyManager = new TransportKeyManagerImpl(
 				db, transportCrypto, dbExecutor, scheduler, clock, transportId,
 				maxLatency);
-		// The timestamp is at the start of rotation period 1000
-		long timestamp = rotationPeriodLength * 1000;
+		// The timestamp is at the start of time period 1000
+		long timestamp = timePeriodLength * 1000;
 		assertEquals(keySetId, transportKeyManager.addContact(txn, contactId,
-				masterKey, timestamp, alice, false));
+				rootKey, timestamp, alice, false));
 		// The keys are inactive so no stream context should be returned
 		assertFalse(transportKeyManager.canSendOutgoingStreams(contactId));
 		assertNull(transportKeyManager.getStreamContext(txn, contactId));
@@ -488,12 +489,12 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 	private void expectAddContactNoRotation(boolean alice, boolean active,
 			TransportKeys transportKeys, Transaction txn) throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(transportCrypto).deriveTransportKeys(transportId, masterKey,
+			oneOf(transportCrypto).deriveTransportKeys(transportId, rootKey,
 					1000, alice, active);
 			will(returnValue(transportKeys));
-			// Get the current time (the start of rotation period 1000)
+			// Get the current time (the start of time period 1000)
 			oneOf(clock).currentTimeMillis();
-			will(returnValue(rotationPeriodLength * 1000));
+			will(returnValue(timePeriodLength * 1000));
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(transportCrypto).encodeTag(
@@ -510,16 +511,16 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 		}});
 	}
 
-	private TransportKeys createTransportKeys(long rotationPeriod,
+	private TransportKeys createTransportKeys(long timePeriod,
 			long streamCounter, boolean active) {
 		IncomingKeys inPrev = new IncomingKeys(tagKey, headerKey,
-				rotationPeriod - 1);
+				timePeriod - 1);
 		IncomingKeys inCurr = new IncomingKeys(tagKey, headerKey,
-				rotationPeriod);
+				timePeriod);
 		IncomingKeys inNext = new IncomingKeys(tagKey, headerKey,
-				rotationPeriod + 1);
+				timePeriod + 1);
 		OutgoingKeys outCurr = new OutgoingKeys(tagKey, headerKey,
-				rotationPeriod, streamCounter, active);
+				timePeriod, streamCounter, active);
 		return new TransportKeys(transportId, inPrev, inCurr, inNext, outCurr);
 	}
 

bramble-core/src/test/java/org/briarproject/bramble/versioning/ClientVersioningManagerImplTest.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.versioning;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.client.ContactGroupFactory;
 import org.briarproject.bramble.api.contact.Contact;
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.data.BdfDictionary;
 import org.briarproject.bramble.api.data.BdfEntry;
 import org.briarproject.bramble.api.data.BdfList;
@@ -11,6 +10,8 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.bramble.api.sync.Group;
 import org.briarproject.bramble.api.sync.Group.Visibility;
@@ -34,13 +35,12 @@ import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
 import static org.briarproject.bramble.api.versioning.ClientVersioningManager.CLIENT_ID;
 import static org.briarproject.bramble.api.versioning.ClientVersioningManager.MAJOR_VERSION;
-import static org.briarproject.bramble.test.TestUtils.getAuthor;
 import static org.briarproject.bramble.test.TestUtils.getClientId;
+import static org.briarproject.bramble.test.TestUtils.getContact;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getLocalAuthor;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
-import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_LOCAL;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_UPDATE_VERSION;
@@ -51,17 +51,18 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 
 	private final DatabaseComponent db = context.mock(DatabaseComponent.class);
 	private final ClientHelper clientHelper = context.mock(ClientHelper.class);
+	private final IdentityManager identityManager =
+			context.mock(IdentityManager.class);
 	private final ContactGroupFactory contactGroupFactory =
 			context.mock(ContactGroupFactory.class);
 	private final Clock clock = context.mock(Clock.class);
 	private final ClientVersioningHook hook =
 			context.mock(ClientVersioningHook.class);
 
+	private final LocalAuthor localAuthor = getLocalAuthor();
 	private final Group localGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
 	private final Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
-	private final Contact contact = new Contact(new ContactId(123),
-			getAuthor(), getLocalAuthor().getId(), getRandomString(5), true,
-			true);
+	private final Contact contact = getContact();
 	private final ClientId clientId = getClientId();
 	private final long now = System.currentTimeMillis();
 	private final Transaction txn = new Transaction(null, false);
@@ -73,7 +74,7 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(localGroup));
 		}});
 		return new ClientVersioningManagerImpl(db, clientHelper,
-				contactGroupFactory, clock);
+				identityManager, contactGroupFactory, clock);
 	}
 
 	@Test
@@ -122,8 +123,10 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 				new BdfEntry(MSG_KEY_LOCAL, true));
 
 		context.checking(new Expectations() {{
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			oneOf(db).addGroup(txn, contactGroup);
 			oneOf(db).setGroupVisibility(txn, contact.getId(),
@@ -143,8 +146,10 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testRemovesGroupWhenRemovingContact() throws Exception {
 		context.checking(new Expectations() {{
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			oneOf(db).removeGroup(txn, contactGroup);
 		}});
@@ -179,10 +184,12 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).addLocalMessage(txn, localVersions, new Metadata(),
 					false);
 			// Inform contacts that client versions have changed
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(db).getContacts(txn);
 			will(returnValue(singletonList(contact)));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			// Find the latest local and remote updates (no remote update)
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
@@ -266,10 +273,12 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).addLocalMessage(txn, newLocalVersions, new Metadata(),
 					false);
 			// Inform contacts that client versions have changed
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(db).getContacts(txn);
 			will(returnValue(singletonList(contact)));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			// Find the latest local and remote updates (no remote update)
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
@@ -362,10 +371,12 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).addLocalMessage(txn, newLocalVersions, new Metadata(),
 					false);
 			// Inform contacts that client versions have changed
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(db).getContacts(txn);
 			will(returnValue(singletonList(contact)));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			// Find the latest local and remote updates
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
@@ -975,8 +986,10 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 		context.checking(new Expectations() {{
 			oneOf(db).getContact(txn, contact.getId());
 			will(returnValue(contact));
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localAuthor));
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
+					MAJOR_VERSION, contact, localAuthor.getId());
 			will(returnValue(contactGroup));
 			oneOf(db).containsGroup(txn, contactGroup.getId());
 			will(returnValue(exists));

bramble-java/src/test/java/org/briarproject/bramble/test/BrambleJavaIntegrationTestComponent.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.test;
 
 import org.briarproject.bramble.BrambleJavaModule;
 import org.briarproject.bramble.battery.DefaultBatteryManagerModule;
+import org.briarproject.bramble.event.DefaultEventExecutorModule;
 import org.briarproject.bramble.event.EventModule;
 import org.briarproject.bramble.plugin.PluginModule;
 import org.briarproject.bramble.plugin.tor.BridgeTest;
@@ -17,8 +18,9 @@ import dagger.Component;
 		BrambleJavaModule.class,
 		TestLifecycleModule.class,
 		DefaultBatteryManagerModule.class,
-		PluginModule.class,  // needed for BackoffFactory
+		DefaultEventExecutorModule.class,
 		EventModule.class,
+		PluginModule.class,  // needed for BackoffFactory
 		SystemModule.class,
 })
 public interface BrambleJavaIntegrationTestComponent {

briar-android/src/main/java/org/briarproject/briar/android/AndroidDatabaseConfig.java

@@ -24,9 +24,4 @@ class AndroidDatabaseConfig implements DatabaseConfig {
 	public File getDatabaseKeyDirectory() {
 		return keyDir;
 	}
-
-	@Override
-	public long getMaxSize() {
-		return Long.MAX_VALUE;
-	}
 }

briar-android/src/main/java/org/briarproject/briar/android/AndroidNotificationManagerImpl.java

@@ -104,9 +104,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	private ContactId blockedContact = null;
 	private GroupId blockedGroup = null;
 	private boolean blockSignInReminder = false;
-	private boolean blockContacts = false, blockGroups = false;
-	private boolean blockForums = false, blockBlogs = false;
-	private boolean blockIntroductions = false;
+	private boolean blockBlogs = false;
 	private long lastSound = 0;
 
 	private volatile Settings settings = new Settings();
@@ -237,7 +235,6 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		}
 	}
 
-
 	@UiThread
 	@Override
 	public Notification getForegroundNotification() {
@@ -261,8 +258,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		b.setContentText(appContext.getText(text));
 		b.setWhen(0); // Don't show the time
 		b.setOngoing(true);
-		Intent i = new Intent(appContext, NavDrawerActivity.class);
-		i.setFlags(FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TOP);
+		Intent i = new Intent(appContext, SplashScreenActivity.class);
 		b.setContentIntent(PendingIntent.getActivity(appContext, 0, i, 0));
 		if (SDK_INT >= 21) {
 			b.setCategory(CATEGORY_SERVICE);
@@ -279,13 +275,11 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		notificationManager.notify(ONGOING_NOTIFICATION_ID, n);
 	}
 
+	@UiThread
 	private void showContactNotification(ContactId c) {
-		androidExecutor.runOnUiThread(() -> {
-			if (blockContacts) return;
-			if (c.equals(blockedContact)) return;
-			contactCounts.add(c);
-			updateContactNotification(true);
-		});
+		if (c.equals(blockedContact)) return;
+		contactCounts.add(c);
+		updateContactNotification(true);
 	}
 
 	@Override
@@ -382,12 +376,9 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 
 	@UiThread
 	private void showGroupMessageNotification(GroupId g) {
-		androidExecutor.runOnUiThread(() -> {
-			if (blockGroups) return;
-			if (g.equals(blockedGroup)) return;
-			groupCounts.add(g);
-			updateGroupMessageNotification(true);
-		});
+		if (g.equals(blockedGroup)) return;
+		groupCounts.add(g);
+		updateGroupMessageNotification(true);
 	}
 
 	@Override
@@ -453,12 +444,9 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 
 	@UiThread
 	private void showForumPostNotification(GroupId g) {
-		androidExecutor.runOnUiThread(() -> {
-			if (blockForums) return;
-			if (g.equals(blockedGroup)) return;
-			forumCounts.add(g);
-			updateForumPostNotification(true);
-		});
+		if (g.equals(blockedGroup)) return;
+		forumCounts.add(g);
+		updateForumPostNotification(true);
 	}
 
 	@Override
@@ -523,12 +511,10 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 
 	@UiThread
 	private void showBlogPostNotification(GroupId g) {
-		androidExecutor.runOnUiThread(() -> {
-			if (blockBlogs) return;
-			if (g.equals(blockedGroup)) return;
-			blogCounts.add(g);
-			updateBlogPostNotification(true);
-		});
+		if (blockBlogs) return;
+		if (g.equals(blockedGroup)) return;
+		blogCounts.add(g);
+		updateBlogPostNotification(true);
 	}
 
 	@Override
@@ -576,12 +562,10 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				(Runnable) this::clearBlogPostNotification);
 	}
 
+	@UiThread
 	private void showIntroductionNotification() {
-		androidExecutor.runOnUiThread(() -> {
-			if (blockIntroductions) return;
-			introductionTotal++;
-			updateIntroductionNotification();
-		});
+		introductionTotal++;
+		updateIntroductionNotification();
 	}
 
 	@UiThread

briar-android/src/main/java/org/briarproject/briar/android/blog/BaseController.java

@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.briar.android.DestroyableContext;
 import org.briarproject.briar.android.controller.handler.ExceptionHandler;
 import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;
 import org.briarproject.briar.api.blog.BlogPostHeader;
@@ -36,10 +35,11 @@ interface BaseController {
 	void repeatPost(BlogPostItem item, @Nullable String comment,
 			ExceptionHandler<DbException> handler);
 
+	@UiThread
 	void setBlogListener(BlogListener listener);
 
 	@NotNullByDefault
-	interface BlogListener extends DestroyableContext {
+	interface BlogListener {
 
 		@UiThread
 		void onBlogPostAdded(BlogPostHeader header, boolean local);

briar-android/src/main/java/org/briarproject/briar/android/blog/BaseControllerImpl.java

@@ -86,15 +86,6 @@ abstract class BaseControllerImpl extends DbControllerImpl
 		this.listener = listener;
 	}
 
-	void onBlogPostAdded(BlogPostHeader h, boolean local) {
-		listener.runOnUiThreadUnlessDestroyed(
-				() -> listener.onBlogPostAdded(h, local));
-	}
-
-	void onBlogRemoved() {
-		listener.runOnUiThreadUnlessDestroyed(() -> listener.onBlogRemoved());
-	}
-
 	@Override
 	public void loadBlogPosts(GroupId groupId,
 			ResultExceptionHandler<Collection<BlogPostItem>, DbException> handler) {