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/**
* Copyright (C) 2014-2016 Open Whisper Systems
*
* Licensed according to the LICENSE file in this repository.
*/
package org.whispersystems.libsignal.state;
import org.whispersystems.libsignal.IdentityKey;
import org.whispersystems.libsignal.IdentityKeyPair;
import org.whispersystems.libsignal.SignalProtocolAddress;
/**
* Provides an interface to identity information.
*
* @author Moxie Marlinspike
*/
public interface IdentityKeyStore {
public enum Direction {
SENDING, RECEIVING
}
/**
* Get the local client's identity key pair.
*
* @return The local client's persistent identity key pair.
*/
public IdentityKeyPair getIdentityKeyPair();
/**
* Return the local client's registration ID.
*
* Clients should maintain a registration ID, a random number
* between 1 and 16380 that's generated once at install time.
*
* @return the local client's registration ID.
*/
public int getLocalRegistrationId();
/**
* Save a remote client's identity key
*
* Store a remote client's identity key as trusted.
*
* @param address The address of the remote client.
* @param identityKey The remote client's identity key.
* @return True if the identity key replaces a previous identity, false if not
*/
public boolean saveIdentity(SignalProtocolAddress address, IdentityKey identityKey);
/**
* Verify a remote client's identity key.
*
* Determine whether a remote client's identity is trusted. Convention is
* that the Signal Protocol is 'trust on first use.' This means that
* an identity key is considered 'trusted' if there is no entry for the recipient
* in the local store, or if it matches the saved key for a recipient in the local
* store. Only if it mismatches an entry in the local store is it considered
* 'untrusted.'
*
* Clients may wish to make a distinction as to how keys are trusted based on the
* direction of travel. For instance, clients may wish to accept all 'incoming' identity
* key changes, while only blocking identity key changes when sending a message.
*
* @param address The address of the remote client.
* @param identityKey The identity key to verify.
* @param direction The direction (sending or receiving) this identity is being used for.
* @return true if trusted, false if untrusted.
*/
public boolean isTrustedIdentity(SignalProtocolAddress address, IdentityKey identityKey, Direction direction);
/**
* Return the saved public identity key for a remote client
*
* @param address The address of the remote client
* @return The public identity key, or null if absent
*/
public IdentityKey getIdentity(SignalProtocolAddress address);
}