Moved classes from messaging package to sync package.

briar-api/src/org/briarproject/api/sync/Ack.java

@@ -0,0 +1,18 @@
+package org.briarproject.api.sync;
+
+import java.util.Collection;
+
+/** A packet acknowledging receipt of one or more {@link Message}s. */
+public class Ack {
+
+	private final Collection<MessageId> acked;
+
+	public Ack(Collection<MessageId> acked) {
+		this.acked = acked;
+	}
+
+	/** Returns the identifiers of the acknowledged messages. */
+	public Collection<MessageId> getMessageIds() {
+		return acked;
+	}
+}

briar-api/src/org/briarproject/api/sync/Group.java

@@ -0,0 +1,55 @@
+package org.briarproject.api.sync;
+
+import java.io.UnsupportedEncodingException;
+
+/** A group to which users may subscribe. */
+public class Group {
+
+	private final GroupId id;
+	private final String name;
+	private final byte[] salt;
+
+	public Group(GroupId id, String name, byte[] salt) {
+		int length;
+		try {
+			length = name.getBytes("UTF-8").length;
+		} catch (UnsupportedEncodingException e) {
+			throw new RuntimeException(e);
+		}
+		if (length == 0 || length > MessagingConstants.MAX_GROUP_NAME_LENGTH)
+			throw new IllegalArgumentException();
+		if (salt.length != MessagingConstants.GROUP_SALT_LENGTH)
+			throw new IllegalArgumentException();
+		this.id = id;
+		this.name = name;
+		this.salt = salt;
+	}
+
+	/** Returns the group's unique identifier. */
+	public GroupId getId() {
+		return id;
+	}
+
+	/** Returns the group's name. */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * Returns the salt used to distinguish the group from other groups with
+	 * the same name.
+	 */
+	public byte[] getSalt() {
+		return salt;
+	}
+
+	@Override
+	public int hashCode() {
+		return id.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof Group && id.equals(((Group) o).id);
+	}
+}

briar-api/src/org/briarproject/api/sync/GroupFactory.java

@@ -0,0 +1,10 @@
+package org.briarproject.api.sync;
+
+public interface GroupFactory {
+
+	/** Creates a group with the given name and a random salt. */
+	Group createGroup(String name);
+
+	/** Creates a group with the given name and salt. */
+	Group createGroup(String name, byte[] salt);
+}

briar-api/src/org/briarproject/api/sync/GroupId.java

@@ -0,0 +1,22 @@
+package org.briarproject.api.sync;
+
+import org.briarproject.api.UniqueId;
+
+import java.util.Arrays;
+
+/**
+ * Type-safe wrapper for a byte array that uniquely identifies a {@link Group}.
+ */
+public class GroupId extends UniqueId {
+
+	public GroupId(byte[] id) {
+		super(id);
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (o instanceof GroupId)
+			return Arrays.equals(id, ((GroupId) o).id);
+		return false;
+	}
+}

briar-api/src/org/briarproject/api/sync/Message.java

@@ -0,0 +1,42 @@
+package org.briarproject.api.sync;
+
+import org.briarproject.api.Author;
+
+public interface Message {
+
+	/** Returns the message's unique identifier. */
+	MessageId getId();
+
+	/**
+	 * Returns the identifier of the message's parent, or null if this is the
+	 * first message in a thread.
+	 */
+	MessageId getParent();
+
+	/**
+	 * Returns the {@link Group} to which the message belongs, or null if this
+	 * is a private message.
+	 */
+	Group getGroup();
+
+	/**
+	 * Returns the message's {@link org.briarproject.api.Author Author}, or null
+	 * if this is an anonymous message.
+	 */
+	Author getAuthor();
+
+	/** Returns the message's content type. */
+	String getContentType();
+
+	/** Returns the message's timestamp in milliseconds since the Unix epoch. */
+	long getTimestamp();
+
+	/** Returns the serialised message. */
+	byte[] getSerialised();
+
+	/** Returns the offset of the message body within the serialised message. */
+	int getBodyStart();
+
+	/** Returns the length of the message body in bytes. */
+	int getBodyLength();
+}

briar-api/src/org/briarproject/api/sync/MessageFactory.java

@@ -0,0 +1,19 @@
+package org.briarproject.api.sync;
+
+import org.briarproject.api.Author;
+import org.briarproject.api.crypto.PrivateKey;
+
+import java.io.IOException;
+import java.security.GeneralSecurityException;
+
+public interface MessageFactory {
+
+	Message createAnonymousMessage(MessageId parent, org.briarproject.api.sync.Group group,
+			String contentType, long timestamp, byte[] body) throws IOException,
+			GeneralSecurityException;
+
+	Message createPseudonymousMessage(MessageId parent, org.briarproject.api.sync.Group group,
+			Author author, PrivateKey privateKey, String contentType,
+			long timestamp, byte[] body) throws IOException,
+			GeneralSecurityException;
+}

briar-api/src/org/briarproject/api/sync/MessageId.java

@@ -0,0 +1,23 @@
+package org.briarproject.api.sync;
+
+import org.briarproject.api.UniqueId;
+
+import java.util.Arrays;
+
+/**
+ * Type-safe wrapper for a byte array that uniquely identifies a
+ * {@link Message}.
+ */
+public class MessageId extends UniqueId {
+
+	public MessageId(byte[] id) {
+		super(id);
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (o instanceof MessageId)
+			return Arrays.equals(id, ((MessageId) o).id);
+		return false;
+	}
+}

briar-api/src/org/briarproject/api/sync/MessageVerifier.java

@@ -0,0 +1,9 @@
+package org.briarproject.api.sync;
+
+import java.security.GeneralSecurityException;
+
+/** Verifies the signatures on an {@link UnverifiedMessage}. */
+public interface MessageVerifier {
+
+	Message verifyMessage(UnverifiedMessage m) throws GeneralSecurityException;
+}

briar-api/src/org/briarproject/api/sync/MessagingConstants.java

@@ -0,0 +1,46 @@
+package org.briarproject.api.sync;
+
+
+public interface MessagingConstants {
+
+	/** The current version of the messaging protocol. */
+	byte PROTOCOL_VERSION = 0;
+
+	/** The length of the packet header in bytes. */
+	int HEADER_LENGTH = 4;
+
+	/** The maximum length of the packet payload in bytes. */
+	int MAX_PAYLOAD_LENGTH = 32 * 1024; // 32 KiB
+
+	/** The maximum number of public groups a user may subscribe to. */
+	int MAX_SUBSCRIPTIONS = 300;
+
+	/** The maximum length of a group's name in UTF-8 bytes. */
+	int MAX_GROUP_NAME_LENGTH = 50;
+
+	/** The length of a group's random salt in bytes. */
+	int GROUP_SALT_LENGTH = 32;
+
+	/**
+	 * The maximum length of a message body in bytes. To allow for future
+	 * changes in the protocol, this is smaller than the maximum payload length
+	 * even when all the message's other fields have their maximum lengths.
+	 */
+	int MAX_BODY_LENGTH = MAX_PAYLOAD_LENGTH - 1024;
+
+	/** The maximum length of a message's content type in UTF-8 bytes. */
+	int MAX_CONTENT_TYPE_LENGTH = 50;
+
+	/** The maximum length of a message's subject line in UTF-8 bytes. */
+	int MAX_SUBJECT_LENGTH = 100;
+
+	/** The length of a message's random salt in bytes. */
+	int MESSAGE_SALT_LENGTH = 32;
+
+	/**
+	 * When calculating the retention time of the database, the timestamp of
+	 * the oldest message in the database is rounded down to a multiple of
+	 * this value to avoid revealing the presence of any particular message.
+	 */
+	int RETENTION_GRANULARITY = 60 * 1000; // 1 minute
+}

briar-api/src/org/briarproject/api/sync/MessagingSession.java

@@ -0,0 +1,18 @@
+package org.briarproject.api.sync;
+
+import java.io.IOException;
+
+public interface MessagingSession {
+
+	/**
+	 * Runs the session. This method returns when there are no more packets to
+	 * send or receive, or when the {@link #interrupt()} method has been called.
+	 */
+	void run() throws IOException;
+
+	/**
+	 * Interrupts the session, causing the {@link #run()} method to return at
+	 * the next opportunity.
+	 */
+	void interrupt();
+}

briar-api/src/org/briarproject/api/sync/MessagingSessionFactory.java

@@ -0,0 +1,19 @@
+package org.briarproject.api.sync;
+
+import org.briarproject.api.ContactId;
+import org.briarproject.api.TransportId;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+
+public interface MessagingSessionFactory {
+
+	MessagingSession createIncomingSession(ContactId c, TransportId t,
+			InputStream in);
+
+	MessagingSession createSimplexOutgoingSession(ContactId c, TransportId t,
+			int maxLatency, OutputStream out);
+
+	MessagingSession createDuplexOutgoingSession(ContactId c, TransportId t,
+			int maxLatency, int maxIdleTime, OutputStream out);
+}

briar-api/src/org/briarproject/api/sync/Offer.java

@@ -0,0 +1,18 @@
+package org.briarproject.api.sync;
+
+import java.util.Collection;
+
+/** A packet offering the recipient one or more {@link Message}s. */
+public class Offer {
+
+	private final Collection<MessageId> offered;
+
+	public Offer(Collection<MessageId> offered) {
+		this.offered = offered;
+	}
+
+	/** Returns the identifiers of the offered messages. */
+	public Collection<MessageId> getMessageIds() {
+		return offered;
+	}
+}

briar-api/src/org/briarproject/api/sync/PacketReader.java

@@ -0,0 +1,38 @@
+package org.briarproject.api.sync;
+
+import java.io.IOException;
+
+public interface PacketReader {
+
+	boolean eof() throws IOException;
+
+	boolean hasAck() throws IOException;
+	Ack readAck() throws IOException;
+
+	boolean hasMessage() throws IOException;
+	UnverifiedMessage readMessage() throws IOException;
+
+	boolean hasOffer() throws IOException;
+	Offer readOffer() throws IOException;
+
+	boolean hasRequest() throws IOException;
+	Request readRequest() throws IOException;
+
+	boolean hasRetentionAck() throws IOException;
+	org.briarproject.api.sync.RetentionAck readRetentionAck() throws IOException;
+
+	boolean hasRetentionUpdate() throws IOException;
+	org.briarproject.api.sync.RetentionUpdate readRetentionUpdate() throws IOException;
+
+	boolean hasSubscriptionAck() throws IOException;
+	org.briarproject.api.sync.SubscriptionAck readSubscriptionAck() throws IOException;
+
+	boolean hasSubscriptionUpdate() throws IOException;
+	org.briarproject.api.sync.SubscriptionUpdate readSubscriptionUpdate() throws IOException;
+
+	boolean hasTransportAck() throws IOException;
+	TransportAck readTransportAck() throws IOException;
+
+	boolean hasTransportUpdate() throws IOException;
+	org.briarproject.api.sync.TransportUpdate readTransportUpdate() throws IOException;
+}

briar-api/src/org/briarproject/api/sync/PacketReaderFactory.java

@@ -0,0 +1,8 @@
+package org.briarproject.api.sync;
+
+import java.io.InputStream;
+
+public interface PacketReaderFactory {
+
+	PacketReader createPacketReader(InputStream in);
+}

briar-api/src/org/briarproject/api/sync/PacketTypes.java

@@ -0,0 +1,16 @@
+package org.briarproject.api.sync;
+
+/** Packet types for the messaging protocol. */
+public interface PacketTypes {
+
+	byte ACK = 0;
+	byte MESSAGE = 1;
+	byte OFFER = 2;
+	byte REQUEST = 3;
+	byte RETENTION_ACK = 4;
+	byte RETENTION_UPDATE = 5;
+	byte SUBSCRIPTION_ACK = 6;
+	byte SUBSCRIPTION_UPDATE = 7;
+	byte TRANSPORT_ACK = 8;
+	byte TRANSPORT_UPDATE = 9;
+}

briar-api/src/org/briarproject/api/sync/PacketWriter.java

@@ -0,0 +1,34 @@
+package org.briarproject.api.sync;
+
+import java.io.IOException;
+
+public interface PacketWriter {
+
+	int getMaxMessagesForAck(long capacity);
+
+	int getMaxMessagesForRequest(long capacity);
+
+	int getMaxMessagesForOffer(long capacity);
+
+	void writeAck(Ack a) throws IOException;
+
+	void writeMessage(byte[] raw) throws IOException;
+
+	void writeOffer(org.briarproject.api.sync.Offer o) throws IOException;
+
+	void writeRequest(Request r) throws IOException;
+
+	void writeRetentionAck(org.briarproject.api.sync.RetentionAck a) throws IOException;
+
+	void writeRetentionUpdate(org.briarproject.api.sync.RetentionUpdate u) throws IOException;
+
+	void writeSubscriptionAck(org.briarproject.api.sync.SubscriptionAck a) throws IOException;
+
+	void writeSubscriptionUpdate(org.briarproject.api.sync.SubscriptionUpdate u) throws IOException;
+
+	void writeTransportAck(org.briarproject.api.sync.TransportAck a) throws IOException;
+
+	void writeTransportUpdate(org.briarproject.api.sync.TransportUpdate u) throws IOException;
+
+	void flush() throws IOException;
+}

briar-api/src/org/briarproject/api/sync/PacketWriterFactory.java

@@ -0,0 +1,8 @@
+package org.briarproject.api.sync;
+
+import java.io.OutputStream;
+
+public interface PacketWriterFactory {
+
+	PacketWriter createPacketWriter(OutputStream out);
+}

briar-api/src/org/briarproject/api/sync/Request.java

@@ -0,0 +1,18 @@
+package org.briarproject.api.sync;
+
+import java.util.Collection;
+
+/** A packet requesting one or more {@link Message}s from the recipient. */
+public class Request {
+
+	private final Collection<org.briarproject.api.sync.MessageId> requested;
+
+	public Request(Collection<org.briarproject.api.sync.MessageId> requested) {
+		this.requested = requested;
+	}
+
+	/** Returns the identifiers of the requested messages. */
+	public Collection<org.briarproject.api.sync.MessageId> getMessageIds() {
+		return requested;
+	}
+}

briar-api/src/org/briarproject/api/sync/RetentionAck.java

@@ -0,0 +1,16 @@
+package org.briarproject.api.sync;
+
+/** A packet acknowledging a (@link RetentionUpdate} */
+public class RetentionAck {
+
+	private final long version;
+
+	public RetentionAck(long version) {
+		this.version = version;
+	}
+
+	/** Returns the version number of the acknowledged update. */
+	public long getVersion() {
+		return version;
+	}
+}

briar-api/src/org/briarproject/api/sync/RetentionUpdate.java

@@ -0,0 +1,23 @@
+package org.briarproject.api.sync;
+
+/**
+ * A packet updating the recipient's view of the retention time of the sender's
+ * database.
+ */
+public class RetentionUpdate {
+
+	private final long retention, version;
+
+	public RetentionUpdate(long retention, long version) {
+		this.retention = retention;
+		this.version = version;
+	}
+
+	public long getRetentionTime() {
+		return retention;
+	}
+
+	public long getVersion() {
+		return version;
+	}
+}

briar-api/src/org/briarproject/api/sync/SubscriptionAck.java

@@ -0,0 +1,16 @@
+package org.briarproject.api.sync;
+
+/** A packet acknowledging a {@link SubscriptionUpdate}. */
+public class SubscriptionAck {
+
+	private final long version;
+
+	public SubscriptionAck(long version) {
+		this.version = version;
+	}
+
+	/** Returns the version number of the acknowledged update. */
+	public long getVersion() {
+		return version;
+	}
+}

briar-api/src/org/briarproject/api/sync/SubscriptionUpdate.java

@@ -0,0 +1,28 @@
+package org.briarproject.api.sync;
+
+import java.util.Collection;
+
+/** A packet updating the recipient's view of the sender's subscriptions. */
+public class SubscriptionUpdate {
+
+	private final Collection<Group> groups;
+	private final long version;
+
+	public SubscriptionUpdate(Collection<Group> groups, long version) {
+		this.groups = groups;
+		this.version = version;
+	}
+
+	/**
+	 * Returns the groups to which the sender subscribes, and which the sender
+	 * has made visible to the recipient.
+	 */
+	public Collection<Group> getGroups() {
+		return groups;
+	}
+
+	/** Returns the update's version number. */
+	public long getVersion() {
+		return version;
+	}
+}

briar-api/src/org/briarproject/api/sync/TransportAck.java

@@ -0,0 +1,25 @@
+package org.briarproject.api.sync;
+
+import org.briarproject.api.TransportId;
+
+/** A packet acknowledging a {@link TransportUpdate}. */
+public class TransportAck {
+
+	private final TransportId id;
+	private final long version;
+
+	public TransportAck(TransportId id, long version) {
+		this.id = id;
+		this.version = version;
+	}
+
+	/** Returns the identifier of the updated transport. */
+	public TransportId getId() {
+		return id;
+	}
+
+	/** Returns the version number of the acknowledged update. */
+	public long getVersion() {
+		return version;
+	}
+}

briar-api/src/org/briarproject/api/sync/TransportUpdate.java

@@ -0,0 +1,36 @@
+package org.briarproject.api.sync;
+
+import org.briarproject.api.TransportId;
+import org.briarproject.api.TransportProperties;
+
+/**
+ * A packet updating the recipient's view of the sender's transport properties.
+ */
+public class TransportUpdate {
+
+	private final TransportId id;
+	private final TransportProperties properties;
+	private final long version;
+
+	public TransportUpdate(TransportId id, TransportProperties properties,
+			long version) {
+		this.id = id;
+		this.properties = properties;
+		this.version = version;
+	}
+
+	/** Returns the identifier of the updated transport. */
+	public TransportId getId() {
+		return id;
+	}
+
+	/** Returns the transport's updated properties. */
+	public TransportProperties getProperties() {
+		return properties;
+	}
+
+	/** Returns the update's version number. */
+	public long getVersion() {
+		return version;
+	}
+}

briar-api/src/org/briarproject/api/sync/UnverifiedMessage.java

@@ -0,0 +1,94 @@
+package org.briarproject.api.sync;
+
+import org.briarproject.api.Author;
+
+/** A {@link Message} that has not yet had its signatures (if any) verified. */
+public class UnverifiedMessage {
+
+	private final MessageId parent;
+	private final org.briarproject.api.sync.Group group;
+	private final Author author;
+	private final String contentType;
+	private final long timestamp;
+	private final byte[] raw, signature;
+	private final int bodyStart, bodyLength, signedLength;
+
+	public UnverifiedMessage(MessageId parent, org.briarproject.api.sync.Group group, Author author,
+			String contentType, long timestamp, byte[] raw, byte[] signature,
+			int bodyStart, int bodyLength, int signedLength) {
+		this.parent = parent;
+		this.group = group;
+		this.author = author;
+		this.contentType = contentType;
+		this.timestamp = timestamp;
+		this.raw = raw;
+		this.signature = signature;
+		this.bodyStart = bodyStart;
+		this.bodyLength = bodyLength;
+		this.signedLength = signedLength;
+	}
+
+	/**
+	 * Returns the identifier of the message's parent, or null if this is the
+	 * first message in a thread.
+	 */
+	public MessageId getParent() {
+		return parent;
+	}
+
+	/**
+	 * Returns the {@link org.briarproject.api.sync.Group} to which the message belongs, or null if this
+	 * is a private message.
+	 */
+	public org.briarproject.api.sync.Group getGroup() {
+		return group;
+	}
+
+	/**
+	 * Returns the message's {@link org.briarproject.api.Author Author}, or null
+	 * if this is an anonymous message.
+	 */
+	public Author getAuthor() {
+		return author;
+	}
+
+	/** Returns the message's content type. */
+	public String getContentType() {
+		return contentType;
+	}
+
+	/** Returns the message's timestamp. */
+	public long getTimestamp() {
+		return timestamp;
+	}
+
+	/** Returns the serialised message. */
+	public byte[] getSerialised() {
+		return raw;
+	}
+
+	/**
+	 * Returns the author's signature, or null if this is an anonymous message.
+	 */
+	public byte[] getSignature() {
+		return signature;
+	}
+
+	/** Returns the offset of the message body within the serialised message. */
+	public int getBodyStart() {
+		return bodyStart;
+	}
+
+	/** Returns the length of the message body in bytes. */
+	public int getBodyLength() {
+		return bodyLength;
+	}
+
+	/**
+	 * Returns the length in bytes of the data covered by the author's
+	 * signature.
+	 */
+	public int getSignedLength() {
+		return signedLength;
+	}
+}