Initial implementation of social backup client.

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

@@ -0,0 +1,47 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.security.GeneralSecurityException;
+
+@NotNullByDefault
+public interface AuthenticatedCipher {
+
+	/**
+	 * Initializes this cipher for encryption or decryption with a key and an
+	 * initialisation vector (IV).
+	 *
+	 * @param encrypt whether we are encrypting or decrypting.
+	 * @param key the key material to use.
+	 * @param iv the IV.
+	 * @throws GeneralSecurityException on invalid input.
+	 */
+	void init(boolean encrypt, SecretKey key, byte[] iv)
+			throws GeneralSecurityException;
+
+	/**
+	 * Encrypts or decrypts data in a single-part operation.
+	 *
+	 * @param input the input byte array. If encrypting, the plaintext to be
+	 * encrypted. If decrypting, the ciphertext to be decrypted
+	 * including the MAC.
+	 * @param inputOff the offset into the input array where the data to be
+	 * processed starts.
+	 * @param len the length of the input. If decrypting, includes the MAC
+	 * length.
+	 * @param output the output byte array. If encrypting, the ciphertext
+	 * including the MAC. If decrypting, the plaintext.
+	 * @param outputOff the offset into the output byte array where the
+	 * processed data starts.
+	 * @return the length of the output. If encrypting, includes the MAC
+	 * length.
+	 * @throws GeneralSecurityException on invalid input.
+	 */
+	int process(byte[] input, int inputOff, int len, byte[] output,
+			int outputOff) throws GeneralSecurityException;
+
+	/**
+	 * Returns the length of the message authentication code (MAC) in bytes.
+	 */
+	int getMacBytes();
+}

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

@@ -26,6 +26,11 @@ public interface IdentityManager {
 	 */
 	void registerIdentity(Identity i);
 
+	/**
+	 * Returns the cached local identity or loads it from the database.
+	 */
+	Identity getIdentity(Transaction txn) throws DbException;
+
 	/**
 	 * Returns the cached local identity or loads it from the database.
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/properties/TransportPropertyManager.java

@@ -74,6 +74,13 @@ public interface TransportPropertyManager {
 	TransportProperties getRemoteProperties(ContactId c, TransportId t)
 			throws DbException;
 
+	/**
+	 * Returns the remote transport properties for the given contact and
+	 * transport.
+	 */
+	TransportProperties getRemoteProperties(Transaction txn, ContactId c,
+			TransportId t) throws DbException;
+
 	/**
 	 * Merges the given properties with the existing local properties for the
 	 * given transport.