Make strict mode warnings configurable

Let StringUtils throw FormatException instead of IllegalArgumentException

See merge request briar/briar!1682

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxId.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.api.mailbox;
 
 import com.fasterxml.jackson.annotation.JsonValue;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
@@ -32,7 +33,7 @@ public abstract class MailboxId extends UniqueId {
 		}
 		try {
 			return fromHexString(token);
-		} catch (IllegalArgumentException e) {
+		} catch (FormatException e) {
 			throw new InvalidMailboxIdException();
 		}
 	}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxProperties.java

@@ -11,7 +11,7 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class MailboxProperties {
 
-	private final String baseUrl;
+	private final String onion;
 	private final MailboxAuthToken authToken;
 	private final boolean owner;
 	private final List<MailboxVersion> serverSupports;
@@ -23,9 +23,9 @@ public class MailboxProperties {
 	/**
 	 * Constructor for properties used by the mailbox's owner.
 	 */
-	public MailboxProperties(String baseUrl, MailboxAuthToken authToken,
+	public MailboxProperties(String onion, MailboxAuthToken authToken,
 			List<MailboxVersion> serverSupports) {
-		this.baseUrl = baseUrl;
+		this.onion = onion;
 		this.authToken = authToken;
 		this.owner = true;
 		this.serverSupports = serverSupports;
@@ -36,10 +36,10 @@ public class MailboxProperties {
 	/**
 	 * Constructor for properties used by a contact of the mailbox's owner.
 	 */
-	public MailboxProperties(String baseUrl, MailboxAuthToken authToken,
+	public MailboxProperties(String onion, MailboxAuthToken authToken,
 			List<MailboxVersion> serverSupports, MailboxFolderId inboxId,
 			MailboxFolderId outboxId) {
-		this.baseUrl = baseUrl;
+		this.onion = onion;
 		this.authToken = authToken;
 		this.owner = false;
 		this.serverSupports = serverSupports;
@@ -47,13 +47,11 @@ public class MailboxProperties {
 		this.outboxId = outboxId;
 	}
 
-	public String getBaseUrl() {
-		return baseUrl;
-	}
-
+	/**
+	 * Returns the onion address of the mailbox, excluding the .onion suffix.
+	 */
 	public String getOnion() {
-		return baseUrl.replaceFirst("^http://", "")
-				.replaceFirst("\\.onion$", "");
+		return onion;
 	}
 
 	public MailboxAuthToken getAuthToken() {

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdateManager.java

@@ -29,19 +29,35 @@ public interface MailboxUpdateManager {
 
 	/**
 	 * The number of properties required for an update message with a mailbox.
+	 * <p>
+	 * The required properties are {@link #PROP_KEY_ONION},
+	 * {@link #PROP_KEY_AUTHTOKEN}, {@link #PROP_KEY_INBOXID} and
+	 * {@link #PROP_KEY_OUTBOXID}.
 	 */
 	int PROP_COUNT = 4;
 
 	/**
-	 * The required properties of an update message with a mailbox.
+	 * The onion address of the mailbox, excluding the .onion suffix.
 	 */
 	String PROP_KEY_ONION = "onion";
+
+	/**
+	 * A bearer token for accessing the mailbox (64 hex digits).
+	 */
 	String PROP_KEY_AUTHTOKEN = "authToken";
+
+	/**
+	 * A folder ID for downloading messages (64 hex digits).
+	 */
 	String PROP_KEY_INBOXID = "inboxId";
+
+	/**
+	 * A folder ID for uploading messages (64 hex digits).
+	 */
 	String PROP_KEY_OUTBOXID = "outboxId";
 
 	/**
-	 * Length of the Onion property.
+	 * Length of the {@link #PROP_KEY_ONION} property.
 	 */
 	int PROP_ONION_LENGTH = 56;
 

bramble-api/src/main/java/org/briarproject/bramble/util/StringUtils.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.util;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.UnsupportedEncodingException;
@@ -95,10 +96,10 @@ public class StringUtils {
 	/**
 	 * Converts the given hex string to a byte array.
 	 */
-	public static byte[] fromHexString(String hex) {
+	public static byte[] fromHexString(String hex) throws FormatException {
 		int len = hex.length();
 		if (len % 2 != 0)
-			throw new IllegalArgumentException("Not a hex string");
+			throw new FormatException();
 		byte[] bytes = new byte[len / 2];
 		for (int i = 0, j = 0; i < len; i += 2, j++) {
 			int high = hexDigitToInt(hex.charAt(i));
@@ -108,11 +109,11 @@ public class StringUtils {
 		return bytes;
 	}
 
-	private static int hexDigitToInt(char c) {
+	private static int hexDigitToInt(char c) throws FormatException {
 		if (c >= '0' && c <= '9') return c - '0';
 		if (c >= 'A' && c <= 'F') return c - 'A' + 10;
 		if (c >= 'a' && c <= 'f') return c - 'a' + 10;
-		throw new IllegalArgumentException("Not a hex digit: " + c);
+		throw new FormatException();
 	}
 
 	public static String trim(String s) {
@@ -130,13 +131,13 @@ public class StringUtils {
 		return MAC.matcher(mac).matches();
 	}
 
-	public static byte[] macToBytes(String mac) {
-		if (!MAC.matcher(mac).matches()) throw new IllegalArgumentException();
+	public static byte[] macToBytes(String mac) throws FormatException {
+		if (!MAC.matcher(mac).matches()) throw new FormatException();
 		return fromHexString(mac.replaceAll(":", ""));
 	}
 
-	public static String macToString(byte[] mac) {
-		if (mac.length != 6) throw new IllegalArgumentException();
+	public static String macToString(byte[] mac) throws FormatException {
+		if (mac.length != 6) throw new FormatException();
 		StringBuilder s = new StringBuilder();
 		for (byte b : mac) {
 			if (s.length() > 0) s.append(':');

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

@@ -230,14 +230,14 @@ public class TestUtils {
 
 	public static MailboxProperties getMailboxProperties(boolean owner,
 			List<MailboxVersion> serverSupports) {
-		String baseUrl = "http://" + getRandomString(56) + ".onion"; // TODO
+		String onion = getRandomString(56);
 		MailboxAuthToken authToken = new MailboxAuthToken(getRandomId());
 		if (owner) {
-			return new MailboxProperties(baseUrl, authToken, serverSupports);
+			return new MailboxProperties(onion, authToken, serverSupports);
 		}
 		MailboxFolderId inboxId = new MailboxFolderId(getRandomId());
 		MailboxFolderId outboxId = new MailboxFolderId(getRandomId());
-		return new MailboxProperties(baseUrl, authToken, serverSupports,
+		return new MailboxProperties(onion, authToken, serverSupports,
 				inboxId, outboxId);
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/account/AccountManagerImpl.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.account;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.DecryptionException;
@@ -209,7 +210,13 @@ class AccountManagerImpl implements AccountManager {
 			LOG.warning("Failed to load encrypted database key");
 			throw new DecryptionException(INVALID_CIPHERTEXT);
 		}
-		byte[] ciphertext = fromHexString(hex);
+		byte[] ciphertext;
+		try {
+			ciphertext = fromHexString(hex);
+		} catch (FormatException e) {
+			LOG.warning("Encrypted database key has invalid format");
+			throw new DecryptionException(INVALID_CIPHERTEXT);
+		}
 		KeyStrengthener keyStrengthener = databaseConfig.getKeyStrengthener();
 		byte[] plaintext = crypto.decryptWithPassword(ciphertext, password,
 				keyStrengthener);

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

@@ -456,8 +456,7 @@ class ClientHelperImpl implements ClientHelper {
 		checkLength(inboxId, UniqueId.LENGTH);
 		byte[] outboxId = properties.getRaw(PROP_KEY_OUTBOXID);
 		checkLength(outboxId, UniqueId.LENGTH);
-		String baseUrl = "http://" + onion + ".onion"; // TODO
-		MailboxProperties props = new MailboxProperties(baseUrl,
+		MailboxProperties props = new MailboxProperties(onion,
 				new MailboxAuthToken(authToken), serverSupportsList,
 				new MailboxFolderId(inboxId), new MailboxFolderId(outboxId));
 		return new MailboxUpdateWithMailbox(clientSupportsList, props);

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiImpl.java

@@ -42,18 +42,22 @@ import static org.briarproject.bramble.util.IoUtils.copyAndClose;
 @NotNullByDefault
 class MailboxApiImpl implements MailboxApi {
 
-	private final WeakSingletonProvider<OkHttpClient> httpClientProvider;
-	private final JsonMapper mapper = JsonMapper.builder()
-			.enable(BLOCK_UNSAFE_POLYMORPHIC_BASE_TYPES)
-			.build();
 	private static final MediaType JSON =
 			requireNonNull(MediaType.parse("application/json; charset=utf-8"));
 	private static final MediaType FILE =
 			requireNonNull(MediaType.parse("application/octet-stream"));
 
+	private final WeakSingletonProvider<OkHttpClient> httpClientProvider;
+	private final JsonMapper mapper = JsonMapper.builder()
+			.enable(BLOCK_UNSAFE_POLYMORPHIC_BASE_TYPES)
+			.build();
+	private final UrlConverter urlConverter;
+
 	@Inject
-	MailboxApiImpl(WeakSingletonProvider<OkHttpClient> httpClientProvider) {
+	MailboxApiImpl(WeakSingletonProvider<OkHttpClient> httpClientProvider,
+			UrlConverter urlConverter) {
 		this.httpClientProvider = httpClientProvider;
+		this.urlConverter = urlConverter;
 	}
 
 	@Override
@@ -78,7 +82,7 @@ class MailboxApiImpl implements MailboxApi {
 			throws IOException, ApiException {
 		if (!properties.isOwner()) throw new IllegalArgumentException();
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(properties.getBaseUrl() + "/setup")
+				.url(getBaseUrl(properties) + "/setup")
 				.put(EMPTY_REQUEST)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
@@ -93,7 +97,7 @@ class MailboxApiImpl implements MailboxApi {
 			if (tokenNode == null) {
 				throw new ApiException();
 			}
-			return new MailboxProperties(properties.getBaseUrl(),
+			return new MailboxProperties(properties.getOnion(),
 					MailboxAuthToken.fromString(tokenNode.textValue()),
 					parseServerSupports(node));
 		} catch (JacksonException | InvalidMailboxIdException e) {
@@ -137,7 +141,7 @@ class MailboxApiImpl implements MailboxApi {
 			throws IOException, ApiException {
 		if (!properties.isOwner()) throw new IllegalArgumentException();
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(properties.getBaseUrl() + "/")
+				.url(getBaseUrl(properties) + "/")
 				.delete()
 				.build();
 		OkHttpClient client = httpClientProvider.get();
@@ -162,7 +166,7 @@ class MailboxApiImpl implements MailboxApi {
 	public void deleteContact(MailboxProperties properties, ContactId contactId)
 			throws IOException, ApiException, TolerableFailureException {
 		if (!properties.isOwner()) throw new IllegalArgumentException();
-		String url = properties.getBaseUrl() + "/contacts/" +
+		String url = getBaseUrl(properties) + "/contacts/" +
 				contactId.getInt();
 		Request request = getRequestBuilder(properties.getAuthToken())
 				.delete()
@@ -266,7 +270,7 @@ class MailboxApiImpl implements MailboxApi {
 		String path = "/files/" + folderId + "/" + fileId;
 		Request request = getRequestBuilder(properties.getAuthToken())
 				.delete()
-				.url(properties.getBaseUrl() + path)
+				.url(getBaseUrl(properties) + path)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
 		Response response = client.newCall(request).execute();
@@ -308,7 +312,7 @@ class MailboxApiImpl implements MailboxApi {
 	private Response sendGetRequest(MailboxProperties properties, String path)
 			throws IOException {
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(properties.getBaseUrl() + path)
+				.url(getBaseUrl(properties) + path)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
 		return client.newCall(request).execute();
@@ -317,7 +321,7 @@ class MailboxApiImpl implements MailboxApi {
 	private Response sendPostRequest(MailboxProperties properties, String path,
 			RequestBody body) throws IOException {
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(properties.getBaseUrl() + path)
+				.url(getBaseUrl(properties) + path)
 				.post(body)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
@@ -339,4 +343,7 @@ class MailboxApiImpl implements MailboxApi {
 		return (ArrayNode) arrayNode;
 	}
 
+	private String getBaseUrl(MailboxProperties properties) {
+		return urlConverter.convertOnionToBaseUrl(properties.getOnion());
+	}
 }

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxModule.java

@@ -59,7 +59,12 @@ public class MailboxModule {
 	}
 
 	@Provides
-	MailboxApi providesMailboxApi(MailboxApiImpl mailboxApi) {
+	UrlConverter provideUrlConverter(UrlConverterImpl urlConverter) {
+		return urlConverter;
+	}
+
+	@Provides
+	MailboxApi provideMailboxApi(MailboxApiImpl mailboxApi) {
 		return mailboxApi;
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxPairingTaskImpl.java

@@ -177,10 +177,9 @@ class MailboxPairingTaskImpl implements MailboxPairingTask {
 		LOG.info("QR code is valid");
 		byte[] onionPubKey = Arrays.copyOfRange(bytes, 1, 33);
 		String onion = crypto.encodeOnion(onionPubKey);
-		String baseUrl = "http://" + onion + ".onion"; // TODO
 		byte[] tokenBytes = Arrays.copyOfRange(bytes, 33, 65);
 		MailboxAuthToken setupToken = new MailboxAuthToken(tokenBytes);
-		return new MailboxProperties(baseUrl, setupToken, new ArrayList<>());
+		return new MailboxProperties(onion, setupToken, new ArrayList<>());
 	}
 
 }

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxSettingsManagerImpl.java

@@ -74,7 +74,7 @@ class MailboxSettingsManagerImpl implements MailboxSettingsManager {
 	public void setOwnMailboxProperties(Transaction txn, MailboxProperties p)
 			throws DbException {
 		Settings s = new Settings();
-		s.put(SETTINGS_KEY_ONION, p.getBaseUrl());
+		s.put(SETTINGS_KEY_ONION, p.getOnion());
 		s.put(SETTINGS_KEY_TOKEN, p.getAuthToken().toString());
 		List<MailboxVersion> serverSupports = p.getServerSupports();
 		encodeServerSupports(serverSupports, s);

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxUpdateManagerImpl.java

@@ -242,8 +242,7 @@ class MailboxUpdateManagerImpl implements MailboxUpdateManager,
 	private void createAndSendUpdateWithMailbox(Transaction txn, Contact c,
 			List<MailboxVersion> serverSupports, String ownOnion)
 			throws DbException {
-		String baseUrl = "http://" + ownOnion + ".onion"; // TODO
-		MailboxProperties properties = new MailboxProperties(baseUrl,
+		MailboxProperties properties = new MailboxProperties(ownOnion,
 				new MailboxAuthToken(crypto.generateUniqueId().getBytes()),
 				serverSupports,
 				new MailboxFolderId(crypto.generateUniqueId().getBytes()),

bramble-core/src/main/java/org/briarproject/bramble/mailbox/UrlConverter.java

@@ -0,0 +1,17 @@
+package org.briarproject.bramble.mailbox;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+/**
+ * An interface for converting an onion address to an HTTP URL, allowing the
+ * conversion to be customised for integration tests.
+ */
+@NotNullByDefault
+interface UrlConverter {
+
+   /**
+    * Converts a raw onion address, excluding the .onion suffix, into an
+    * HTTP URL.
+    */
+   String convertOnionToBaseUrl(String onion);
+}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/UrlConverterImpl.java

@@ -0,0 +1,18 @@
+package org.briarproject.bramble.mailbox;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.inject.Inject;
+
+@NotNullByDefault
+class UrlConverterImpl implements UrlConverter {
+
+	@Inject
+	UrlConverterImpl() {
+	}
+
+	@Override
+	public String convertOnionToBaseUrl(String onion) {
+		return "http://" + onion + ".onion";
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/AbstractBluetoothPlugin.java

@@ -427,7 +427,13 @@ abstract class AbstractBluetoothPlugin<S, SS> implements BluetoothPlugin,
 		BdfList descriptor = new BdfList();
 		descriptor.add(TRANSPORT_ID_BLUETOOTH);
 		String address = getBluetoothAddress();
-		if (address != null) descriptor.add(macToBytes(address));
+		if (address != null) {
+			try {
+				descriptor.add(macToBytes(address));
+			} catch (FormatException e) {
+				throw new RuntimeException();
+			}
+		}
 		return new BluetoothKeyAgreementListener(descriptor, ss);
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java

@@ -285,7 +285,7 @@ class LanTcpPlugin extends TcpPlugin {
 				if (ip.length == 16) addrs.add(InetAddress.getByAddress(ip));
 			}
 			return addrs;
-		} catch (IllegalArgumentException | UnknownHostException e) {
+		} catch (FormatException | UnknownHostException e) {
 			return emptyList();
 		}
 	}

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.connection;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.connection.InterruptibleConnection;
 import org.briarproject.bramble.api.contact.ContactId;
@@ -57,6 +58,10 @@ public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 	private final Priority high =
 			new Priority(fromHexString("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"));
 
+	public ConnectionRegistryImplTest() throws FormatException {
+		// required for throws declaration
+	}
+
 	@Test
 	public void testRegisterMultipleConnections() {
 		context.checking(new Expectations() {{

bramble-core/src/test/java/org/briarproject/bramble/crypto/Blake2bDigestTest.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.crypto;
 
 import org.bouncycastle.crypto.digests.Blake2bDigest;
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.util.StringUtils;
 import org.junit.Test;
@@ -47,7 +48,7 @@ public class Blake2bDigestTest extends BrambleTestCase {
 	};
 
 	@Test
-	public void testDigestWithKeyedTestVectors() {
+	public void testDigestWithKeyedTestVectors() throws FormatException {
 		for (String[] keyedTestVector : KEYED_TEST_VECTORS) {
 			byte[] input = StringUtils.fromHexString(keyedTestVector[0]);
 			byte[] key = StringUtils.fromHexString(keyedTestVector[1]);
@@ -63,7 +64,8 @@ public class Blake2bDigestTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testDigestWithKeyedTestVectorsAndRandomUpdate() {
+	public void testDigestWithKeyedTestVectorsAndRandomUpdate()
+			throws FormatException {
 		Random random = new Random();
 		for (int i = 0; i < 100; i++) {
 			for (String[] keyedTestVector : KEYED_TEST_VECTORS) {
@@ -138,7 +140,7 @@ public class Blake2bDigestTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void runSelfTest() {
+	public void runSelfTest() throws FormatException {
 		Blake2bDigest testDigest = new Blake2bDigest(256);
 		byte[] md = new byte[64];
 

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.crypto.AgreementPublicKey;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.KeyPair;
@@ -83,7 +84,7 @@ public class KeyAgreementTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testRfc7748TestVector() {
+	public void testRfc7748TestVector() throws FormatException {
 		byte[] aPriv = parsePrivateKey(ALICE_PRIVATE);
 		byte[] aPub = fromHexString(ALICE_PUBLIC);
 		byte[] bPriv = parsePrivateKey(BOB_PRIVATE);
@@ -97,7 +98,8 @@ public class KeyAgreementTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testDerivesSameSharedSecretFromEquivalentPublicKey() {
+	public void testDerivesSameSharedSecretFromEquivalentPublicKey()
+			throws FormatException {
 		byte[] aPub = fromHexString(ALICE_PUBLIC);
 		byte[] bPriv = parsePrivateKey(BOB_PRIVATE);
 		byte[] sharedSecret = fromHexString(SHARED_SECRET);
@@ -168,7 +170,7 @@ public class KeyAgreementTest extends BrambleTestCase {
 		return crypto.deriveSharedSecret(label, publicKey, keyPair, inputs);
 	}
 
-	private byte[] parsePrivateKey(String hex) {
+	private byte[] parsePrivateKey(String hex) throws FormatException {
 		// Private keys need to be clamped because curve25519-java does the
 		// clamping at key generation time, not multiplication time
 		return AgreementKeyParser.clamp(fromHexString(hex));

bramble-core/src/test/java/org/briarproject/bramble/crypto/XSalsa20Poly1305AuthenticatedCipherTest.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.util.StringUtils;
@@ -15,11 +16,11 @@ public class XSalsa20Poly1305AuthenticatedCipherTest extends BrambleTestCase {
 
 	// Test vectors from the NaCl paper
 	// http://cr.yp.to/highspeed/naclcrypto-20090310.pdf
-	private static final byte[] TEST_KEY = StringUtils.fromHexString(
+	private final byte[] TEST_KEY = StringUtils.fromHexString(
 			"1b27556473e985d462cd51197a9a46c76009549eac6474f206c4ee0844f68389");
-	private static final byte[] TEST_IV = StringUtils.fromHexString(
+	private final byte[] TEST_IV = StringUtils.fromHexString(
 			"69696ee955b62b73cd62bda875fc73d68219e0036b7a0b37");
-	private static final byte[] TEST_PLAINTEXT = StringUtils.fromHexString(
+	private final byte[] TEST_PLAINTEXT = StringUtils.fromHexString(
 					"be075fc53c81f2d5cf141316" +
 					"ebeb0c7b5228c52a4c62cbd4" +
 					"4b66849b64244ffce5ecbaaf" +
@@ -31,7 +32,7 @@ public class XSalsa20Poly1305AuthenticatedCipherTest extends BrambleTestCase {
 					"048977eb48f59ffd4924ca1c" +
 					"60902e52f0a089bc76897040" +
 					"e082f937763848645e0705");
-	private static final byte[] TEST_CIPHERTEXT = StringUtils.fromHexString(
+	private final byte[] TEST_CIPHERTEXT = StringUtils.fromHexString(
 					"f3ffc7703f9400e52a7dfb4b" +
 					"3d3305d98e993b9f48681273" +
 					"c29650ba32fc76ce48332ea7" +
@@ -46,6 +47,10 @@ public class XSalsa20Poly1305AuthenticatedCipherTest extends BrambleTestCase {
 					"a43d14a6599b1f654cb45a74" +
 					"e355a5");
 
+	public XSalsa20Poly1305AuthenticatedCipherTest() throws FormatException {
+		// required for throws declaration
+	}
+
 	@Test
 	public void testEncrypt() throws Exception {
 		SecretKey k = new SecretKey(TEST_KEY);

bramble-core/src/test/java/org/briarproject/bramble/data/BdfReaderImplTest.java

@@ -618,11 +618,12 @@ public class BdfReaderImplTest extends BrambleTestCase {
 		r.readDictionary();
 	}
 
-	private void setContents(String hex) {
+	private void setContents(String hex) throws FormatException {
 		setContents(hex, DEFAULT_MAX_BUFFER_SIZE);
 	}
 
-	private void setContents(String hex, int maxBufferSize) {
+	private void setContents(String hex, int maxBufferSize)
+			throws FormatException {
 		ByteArrayInputStream in = new ByteArrayInputStream(fromHexString(hex));
 		r = new BdfReaderImpl(in, DEFAULT_NESTED_LIMIT, maxBufferSize);
 	}

bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxApiTest.java

@@ -68,7 +68,10 @@ public class MailboxApiTest extends BrambleTestCase {
 					return client;
 				}
 			};
-	private final MailboxApiImpl api = new MailboxApiImpl(httpClientProvider);
+	// We aren't using a real onion address, so use the given address verbatim
+	private final UrlConverter urlConverter = onion -> onion;
+	private final MailboxApiImpl api = new MailboxApiImpl(httpClientProvider,
+			urlConverter);
 
 	private final MailboxAuthToken token = new MailboxAuthToken(getRandomId());
 	private final MailboxAuthToken token2 = new MailboxAuthToken(getRandomId());

bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxIntegrationTest.java

@@ -49,8 +49,8 @@ public class MailboxIntegrationTest extends BrambleTestCase {
 	@Rule
 	public TemporaryFolder folder = new TemporaryFolder();
 
-	private final static String URL_BASE = "http://127.0.0.1:8000";
-	private final static MailboxAuthToken SETUP_TOKEN;
+	private static final String URL_BASE = "http://127.0.0.1:8000";
+	private static final MailboxAuthToken SETUP_TOKEN;
 
 	static {
 		try {
@@ -74,8 +74,10 @@ public class MailboxIntegrationTest extends BrambleTestCase {
 					return client;
 				}
 			};
-	private final static MailboxApiImpl api =
-			new MailboxApiImpl(httpClientProvider);
+	// We aren't using a real onion address, so use the given address verbatim
+	private static final UrlConverter urlConverter = onion -> onion;
+	private static final MailboxApiImpl api =
+			new MailboxApiImpl(httpClientProvider, urlConverter);
 	// needs to be static to keep values across different tests
 	private static MailboxProperties ownerProperties;
 
@@ -121,7 +123,7 @@ public class MailboxIntegrationTest extends BrambleTestCase {
 		ContactId contactId = new ContactId(1);
 		MailboxContact contact = getMailboxContact(contactId);
 		MailboxProperties contactProperties = new MailboxProperties(
-				ownerProperties.getBaseUrl(), contact.token,
+				ownerProperties.getOnion(), contact.token,
 				new ArrayList<>(), contact.inboxId, contact.outboxId);
 		api.addContact(ownerProperties, contact);
 
@@ -167,7 +169,7 @@ public class MailboxIntegrationTest extends BrambleTestCase {
 		ContactId contactId = new ContactId(1);
 		MailboxContact contact = getMailboxContact(contactId);
 		MailboxProperties contactProperties = new MailboxProperties(
-				ownerProperties.getBaseUrl(), contact.token,
+				ownerProperties.getOnion(), contact.token,
 				new ArrayList<>(), contact.inboxId, contact.outboxId);
 		api.addContact(ownerProperties, contact);
 

bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxPairingTaskImplTest.java

@@ -55,7 +55,6 @@ public class MailboxPairingTaskImplTest extends BrambleMockTestCase {
 
 	private final String onion = getRandomString(56);
 	private final byte[] onionBytes = getRandomBytes(32);
-	private final String baseUrl = "http://" + onion + ".onion"; // TODO
 	private final MailboxAuthToken setupToken =
 			new MailboxAuthToken(getRandomId());
 	private final MailboxAuthToken ownerToken =
@@ -63,9 +62,9 @@ public class MailboxPairingTaskImplTest extends BrambleMockTestCase {
 	private final String validPayload = getValidPayload();
 	private final long time = System.currentTimeMillis();
 	private final MailboxProperties setupProperties = new MailboxProperties(
-			baseUrl, setupToken, new ArrayList<>());
+			onion, setupToken, new ArrayList<>());
 	private final MailboxProperties ownerProperties = new MailboxProperties(
-			baseUrl, ownerToken, new ArrayList<>());
+			onion, ownerToken, new ArrayList<>());
 
 	@Test
 	public void testInitialQrCodeReceivedState() {
@@ -207,7 +206,7 @@ public class MailboxPairingTaskImplTest extends BrambleMockTestCase {
 	private PredicateMatcher<MailboxProperties> matches(MailboxProperties p2) {
 		return new PredicateMatcher<>(MailboxProperties.class, p1 ->
 				p1.getAuthToken().equals(p2.getAuthToken()) &&
-						p1.getBaseUrl().equals(p2.getBaseUrl()) &&
+						p1.getOnion().equals(p2.getOnion()) &&
 						p1.isOwner() == p2.isOwner() &&
 						p1.getServerSupports().equals(p2.getServerSupports()));
 	}

bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxSettingsManagerImplTest.java

@@ -84,7 +84,7 @@ public class MailboxSettingsManagerImplTest extends BrambleMockTestCase {
 
 		MailboxProperties properties = manager.getOwnMailboxProperties(txn);
 		assertNotNull(properties);
-		assertEquals(onion, properties.getBaseUrl());
+		assertEquals(onion, properties.getOnion());
 		assertEquals(token, properties.getAuthToken());
 		assertEquals(serverSupports, properties.getServerSupports());
 		assertTrue(properties.isOwner());

bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxUpdateManagerImplTest.java

@@ -109,7 +109,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 		updateNoMailbox = new MailboxUpdate(someClientSupportsList);
 
 		updateProps = getMailboxProperties(false, someServerSupportsList);
-		ownProps = new MailboxProperties(updateProps.getBaseUrl(),
+		ownProps = new MailboxProperties(updateProps.getOnion(),
 				updateProps.getAuthToken(), someServerSupportsList);
 		updateWithMailbox = new MailboxUpdateWithMailbox(someClientSupportsList,
 				updateProps);
@@ -170,7 +170,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId());
 			will(returnValue(messageMetadata));
 			expectStoreMessage(txn, contactGroup.getId(), 1, someClientSupports,
-					emptyServerSupports, emptyPropsDict, true);
+					emptyServerSupports, emptyPropsDict);
 
 			oneOf(clientHelper).mergeGroupMetadata(txn, localGroup.getId(),
 					sentDict);
@@ -225,7 +225,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId());
 			will(returnValue(messageMetadata));
 			expectStoreMessage(txn, contactGroup.getId(), 1, someClientSupports,
-					someServerSupports, propsDict, true);
+					someServerSupports, propsDict);
 
 			oneOf(clientHelper).mergeGroupMetadata(txn, localGroup.getId(),
 					sentDict);
@@ -276,7 +276,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId());
 			will(returnValue(emptyMessageMetadata));
 			expectStoreMessage(txn, contactGroup.getId(), 1, someClientSupports,
-					emptyServerSupports, emptyPropsDict, true);
+					emptyServerSupports, emptyPropsDict);
 
 			oneOf(clientHelper).mergeGroupMetadata(txn, localGroup.getId(),
 					sentDict);
@@ -341,7 +341,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId());
 			will(returnValue(emptyMessageMetadata));
 			expectStoreMessage(txn, contactGroup.getId(), 1, someClientSupports,
-					emptyServerSupports, emptyPropsDict, true);
+					emptyServerSupports, emptyPropsDict);
 
 			oneOf(clientHelper).mergeGroupMetadata(txn, localGroup.getId(),
 					sentDict);
@@ -400,7 +400,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId());
 			will(returnValue(messageMetadata));
 			expectStoreMessage(txn, contactGroup.getId(), 2,
-					newerClientSupports, someServerSupports, propsDict, true);
+					newerClientSupports, someServerSupports, propsDict);
 			oneOf(db).removeMessage(txn, messageId);
 
 			oneOf(clientHelper).mergeGroupMetadata(txn, localGroup.getId(),
@@ -441,7 +441,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId());
 			will(returnValue(messageMetadata));
 			expectStoreMessage(txn, contactGroup.getId(), 1, someClientSupports,
-					emptyServerSupports, emptyPropsDict, true);
+					emptyServerSupports, emptyPropsDict);
 		}});
 
 		MailboxUpdateManagerImpl t = createInstance(someClientSupportsList);
@@ -484,7 +484,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId());
 			will(returnValue(messageMetadata));
 			expectStoreMessage(txn, contactGroup.getId(), 1, someClientSupports,
-					someServerSupports, propsDict, true);
+					someServerSupports, propsDict);
 		}});
 
 		MailboxUpdateManagerImpl t = createInstance(someClientSupportsList);
@@ -674,7 +674,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId());
 			will(returnValue(messageMetadata));
 			expectStoreMessage(txn, contactGroup.getId(), 2, someClientSupports,
-					someServerSupports, propsDict, true);
+					someServerSupports, propsDict);
 			oneOf(db).removeMessage(txn, latestId);
 		}});
 
@@ -712,7 +712,7 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 					contactGroup.getId());
 			will(returnValue(messageMetadata));
 			expectStoreMessage(txn, contactGroup.getId(), 2, someClientSupports,
-					emptyServerSupports, emptyPropsDict, true);
+					emptyServerSupports, emptyPropsDict);
 			oneOf(db).removeMessage(txn, latestId);
 		}});
 
@@ -890,15 +890,14 @@ public class MailboxUpdateManagerImplTest extends BrambleMockTestCase {
 
 	private void expectStoreMessage(Transaction txn, GroupId g,
 			long version, BdfList clientSupports, BdfList serverSupports,
-			BdfDictionary properties, boolean local)
-			throws Exception {
+			BdfDictionary properties) throws Exception {
 		BdfList body = BdfList.of(version, clientSupports, serverSupports,
 				properties);
 		Message message = getMessage(g);
 		long timestamp = message.getTimestamp();
 		BdfDictionary meta = BdfDictionary.of(
 				new BdfEntry(MSG_KEY_VERSION, version),
-				new BdfEntry(MSG_KEY_LOCAL, local)
+				new BdfEntry(MSG_KEY_LOCAL, true)
 		);
 
 		context.checking(new Expectations() {{

bramble-core/src/test/java/org/briarproject/bramble/util/ByteUtilsTest.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.util;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.junit.Test;
 
@@ -11,7 +12,7 @@ import static org.junit.Assert.fail;
 public class ByteUtilsTest extends BrambleTestCase {
 
 	@Test
-	public void testReadUint16() {
+	public void testReadUint16() throws FormatException {
 		byte[] b = StringUtils.fromHexString("00000000");
 		assertEquals(0, ByteUtils.readUint16(b, 1));
 		b = StringUtils.fromHexString("00000100");
@@ -33,7 +34,7 @@ public class ByteUtilsTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testReadUint32() {
+	public void testReadUint32() throws FormatException {
 		byte[] b = StringUtils.fromHexString("000000000000");
 		assertEquals(0, ByteUtils.readUint32(b, 1));
 		b = StringUtils.fromHexString("000000000100");
@@ -55,7 +56,7 @@ public class ByteUtilsTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testReadUint64() {
+	public void testReadUint64() throws FormatException {
 		byte[] b = StringUtils.fromHexString("00000000000000000000");
 		assertEquals(0L, ByteUtils.readUint64(b, 1));
 		b = StringUtils.fromHexString("00000000000000000100");

bramble-core/src/test/java/org/briarproject/bramble/util/StringUtilsTest.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.util;
 
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.junit.Test;
 
@@ -24,18 +25,19 @@ public class StringUtilsTest extends BrambleTestCase {
 		assertEquals("", StringUtils.toHexString(new byte[0]));
 	}
 
-	@Test(expected = IllegalArgumentException.class)
-	public void testFromHexStringRejectsInvalidLength() {
+	@Test(expected = FormatException.class)
+	public void testFromHexStringRejectsInvalidLength() throws FormatException {
 		StringUtils.fromHexString("12345");
 	}
 
-	@Test(expected = IllegalArgumentException.class)
-	public void testFromHexStringRejectsInvalidCharacter() {
+	@Test(expected = FormatException.class)
+	public void testFromHexStringRejectsInvalidCharacter()
+			throws FormatException {
 		StringUtils.fromHexString("ABCDEFGH");
 	}
 
 	@Test
-	public void testFromHexStringUppercase() {
+	public void testFromHexStringUppercase() throws FormatException {
 		String s = "000102037F800A0B0C0D0EFF";
 		byte[] expected = new byte[] {
 				0x00, 0x01, 0x02, 0x03, 0x7F, (byte) 0x80,
@@ -45,7 +47,7 @@ public class StringUtilsTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testFromHexStringLowercase() {
+	public void testFromHexStringLowercase() throws FormatException {
 		String s = "000102037f800a0b0c0d0eff";
 		byte[] expected = new byte[] {
 				0x00, 0x01, 0x02, 0x03, 0x7F, (byte) 0x80,
@@ -55,7 +57,7 @@ public class StringUtilsTest extends BrambleTestCase {
 	}
 
 	@Test
-	public void testFromHexStringEmptyInput() {
+	public void testFromHexStringEmptyInput() throws FormatException {
 		assertArrayEquals(new byte[0], StringUtils.fromHexString(""));
 	}
 
@@ -174,52 +176,52 @@ public class StringUtilsTest extends BrambleTestCase {
 		assertEquals("", StringUtils.truncateUtf8("", 123));
 	}
 
-	@Test(expected = IllegalArgumentException.class)
-	public void testMacToBytesRejectsShortMac() {
+	@Test(expected = FormatException.class)
+	public void testMacToBytesRejectsShortMac() throws FormatException {
 		StringUtils.macToBytes("00:00:00:00:00");
 	}
 
-	@Test(expected = IllegalArgumentException.class)
-	public void testMacToBytesRejectsLongMac() {
+	@Test(expected = FormatException.class)
+	public void testMacToBytesRejectsLongMac() throws FormatException {
 		StringUtils.macToBytes("00:00:00:00:00:00:00");
 	}
 
-	@Test(expected = IllegalArgumentException.class)
-	public void testMacToBytesRejectsInvalidCharacter() {
+	@Test(expected = FormatException.class)
+	public void testMacToBytesRejectsInvalidCharacter() throws FormatException {
 		StringUtils.macToBytes("00:00:00:00:00:0g");
 	}
 
-	@Test(expected = IllegalArgumentException.class)
-	public void testMacToBytesRejectsInvalidFormat() {
+	@Test(expected = FormatException.class)
+	public void testMacToBytesRejectsInvalidFormat() throws FormatException {
 		StringUtils.macToBytes("0:000:00:00:00:00");
 	}
 
 	@Test
-	public void testMacToBytesUpperCase() {
+	public void testMacToBytesUpperCase() throws FormatException {
 		byte[] expected = new byte[] {0x0A, 0x1B, 0x2C, 0x3D, 0x4E, 0x5F};
 		String mac = "0A:1B:2C:3D:4E:5F";
 		assertArrayEquals(expected, StringUtils.macToBytes(mac));
 	}
 
 	@Test
-	public void testMacToBytesLowerCase() {
+	public void testMacToBytesLowerCase() throws FormatException {
 		byte[] expected = new byte[] {0x0A, 0x1B, 0x2C, 0x3D, 0x4E, 0x5F};
 		String mac = "0a:1b:2c:3d:4e:5f";
 		assertArrayEquals(expected, StringUtils.macToBytes(mac));
 	}
 
-	@Test(expected = IllegalArgumentException.class)
-	public void testMacToStringRejectsShortMac() {
+	@Test(expected = FormatException.class)
+	public void testMacToStringRejectsShortMac() throws FormatException {
 		StringUtils.macToString(new byte[5]);
 	}
 
-	@Test(expected = IllegalArgumentException.class)
-	public void testMacToStringRejectsLongMac() {
+	@Test(expected = FormatException.class)
+	public void testMacToStringRejectsLongMac() throws FormatException {
 		StringUtils.macToString(new byte[7]);
 	}
 
 	@Test
-	public void testMacToString() {
+	public void testMacToString() throws FormatException {
 		byte[] mac = new byte[] {0x0a, 0x1b, 0x2c, 0x3d, 0x4e, 0x5f};
 		String expected = "0A:1B:2C:3D:4E:5F";
 		assertEquals(expected, StringUtils.macToString(mac));

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

@@ -8,6 +8,7 @@ import android.os.StrictMode;
 import com.vanniktech.emoji.RecentEmoji;
 
 import org.briarproject.bramble.api.FeatureFlags;
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.crypto.PublicKey;
@@ -242,7 +243,7 @@ public class AppModule {
 				try {
 					return crypto.getMessageKeyParser().parsePublicKey(
 							StringUtils.fromHexString(DEV_PUBLIC_KEY_HEX));
-				} catch (GeneralSecurityException e) {
+				} catch (GeneralSecurityException | FormatException e) {
 					throw new RuntimeException(e);
 				}
 			}

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

@@ -6,6 +6,8 @@ import android.app.Application;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.content.res.Configuration;
+import android.os.Build;
+import android.os.Build.VERSION_CODES;
 import android.os.StrictMode;
 import android.os.StrictMode.ThreadPolicy;
 import android.os.StrictMode.VmPolicy;
@@ -120,12 +122,62 @@ public class BriarApplicationImpl extends Application
 	}
 
 	private void enableStrictMode() {
+		int targetSdk = Build.VERSION.SDK_INT;
+
 		ThreadPolicy.Builder threadPolicy = new ThreadPolicy.Builder();
-		threadPolicy.detectAll();
+
+		// pulled in from threadPolicy.detectAll();
+		threadPolicy.detectDiskReads();
+		threadPolicy.detectDiskWrites();
+		threadPolicy.detectNetwork();
+
+		if (targetSdk >= VERSION_CODES.HONEYCOMB) {
+			threadPolicy.detectCustomSlowCalls();
+		}
+		if (targetSdk >= VERSION_CODES.M) {
+			threadPolicy.detectResourceMismatches();
+		}
+		if (targetSdk >= VERSION_CODES.O) {
+			threadPolicy.detectUnbufferedIo();
+		}
+		// -- end detectAll()
+
 		threadPolicy.penaltyLog();
 		StrictMode.setThreadPolicy(threadPolicy.build());
+
 		VmPolicy.Builder vmPolicy = new VmPolicy.Builder();
-		vmPolicy.detectAll();
+
+		// pulled in from vmPolicy.detectAll();
+		vmPolicy.detectLeakedSqlLiteObjects();
+		if (targetSdk >= VERSION_CODES.HONEYCOMB) {
+			vmPolicy.detectActivityLeaks();
+			vmPolicy.detectLeakedClosableObjects();
+		}
+		if (targetSdk >= VERSION_CODES.JELLY_BEAN) {
+			vmPolicy.detectLeakedRegistrationObjects();
+		}
+		if (targetSdk >= VERSION_CODES.JELLY_BEAN_MR2) {
+			vmPolicy.detectFileUriExposure();
+		}
+		if (targetSdk >= VERSION_CODES.M) {
+			vmPolicy.detectCleartextNetwork();
+		}
+		if (targetSdk >= VERSION_CODES.O) {
+			vmPolicy.detectContentUriWithoutPermission();
+			// do not detect untagged sockets
+			// vmPolicy.detectUntaggedSockets();
+		}
+		if (targetSdk >= VERSION_CODES.Q) {
+			vmPolicy.detectCredentialProtectedWhileLocked();
+		}
+		if (targetSdk >= VERSION_CODES.R) {
+			// for some reason this won't compile
+			// vmPolicy.detectIncorrectContextUse();
+		}
+		// -- end detectAll()
+
+		// TODO: add detectUnsafeIntentLaunch() after upgrading to API level 31
+
 		vmPolicy.penaltyLog();
 		StrictMode.setVmPolicy(vmPolicy.build());
 	}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -22,6 +22,7 @@ import android.widget.Toast;
 import com.google.android.material.snackbar.Snackbar;
 
 import org.briarproject.bramble.api.FeatureFlags;
+import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
@@ -519,8 +520,12 @@ public class ConversationActivity extends BriarActivity
 		Selection<String> selection = tracker.getSelection();
 		List<MessageId> messages = new ArrayList<>(selection.size());
 		for (String str : selection) {
-			MessageId id = new MessageId(fromHexString(str));
-			messages.add(id);
+			try {
+				MessageId id = new MessageId(fromHexString(str));
+				messages.add(id);
+			} catch (FormatException e) {
+				LOG.warning("Invalid message id");
+			}
 		}
 		return messages;
 	}

briar-android/src/main/java/org/briarproject/briar/android/mailbox/MailboxActivity.java

@@ -109,12 +109,18 @@ public class MailboxActivity extends BriarActivity {
 	}
 
 	private void onShowDownload() {
+		boolean needToShow = true;
 		FragmentManager fm = getSupportFragmentManager();
+		// if the fragment is already on the back stack, pop back to it
+		// instead of adding it to the stack again
 		if (fm.findFragmentByTag(SetupDownloadFragment.TAG) != null) {
-			// if the fragment is already on the back stack, pop back to it
-			// instead of adding it to the stack again
-			fm.popBackStackImmediate(SetupDownloadFragment.TAG, 0);
-		} else {
+			// if the activity was previously destroyed, the fragment is still
+			// found, but popping back to it won't work, so we need to handle
+			// this case and show the fragment again anyway.
+			needToShow =
+					!fm.popBackStackImmediate(SetupDownloadFragment.TAG, 0);
+		}
+		if (needToShow) {
 			showFragment(fm, new SetupDownloadFragment(),
 					SetupDownloadFragment.TAG);
 		}