private May<uint> processV3(SessionRecord sessionRecord, PreKeyWhisperMessage message)
{
if (sessionRecord.hasSessionState(message.getMessageVersion(), message.getBaseKey().serialize()))
{
//Log.w(TAG, "We've already setup a session for this V3 message, letting bundled message fall through...");
return May<uint>.NoValue;
}
ECKeyPair ourSignedPreKey = signedPreKeyStore.LoadSignedPreKey(message.getSignedPreKeyId()).getKeyPair();
BobAxolotlParameters.Builder parameters = BobAxolotlParameters.newBuilder();
parameters.setTheirBaseKey(message.getBaseKey())
.setTheirIdentityKey(message.getIdentityKey())
.setOurIdentityKey(identityKeyStore.GetIdentityKeyPair())
.setOurSignedPreKey(ourSignedPreKey)
.setOurRatchetKey(ourSignedPreKey);
if (message.getPreKeyId().HasValue)
{
parameters.setOurOneTimePreKey(new May<ECKeyPair>(preKeyStore.LoadPreKey(message.getPreKeyId().ForceGetValue()).getKeyPair()));
}
else
{
parameters.setOurOneTimePreKey(May<ECKeyPair>.NoValue);
}
if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
RatchetingSession.initializeSession(sessionRecord.getSessionState(), message.getMessageVersion(), parameters.create());
sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.GetLocalRegistrationId());
sessionRecord.getSessionState().setRemoteRegistrationId(message.getRegistrationId());
sessionRecord.getSessionState().setAliceBaseKey(message.getBaseKey().serialize());
if (message.getPreKeyId().HasValue && message.getPreKeyId().ForceGetValue() != Medium.MAX_VALUE)
{
return message.getPreKeyId();
}
else
{
return May<uint>.NoValue;
}
}
private May<uint> processV2(SessionRecord sessionRecord, PreKeyWhisperMessage message)
{
if (!message.getPreKeyId().HasValue)
{
throw new InvalidKeyIdException("V2 message requires one time prekey id!");
}
if (!preKeyStore.ContainsPreKey(message.getPreKeyId().ForceGetValue()) &&
sessionStore.ContainsSession(remoteAddress))
{
//Log.w(TAG, "We've already processed the prekey part of this V2 session, letting bundled message fall through...");
return May<uint>.NoValue; //May.absent();
}
ECKeyPair ourPreKey = preKeyStore.LoadPreKey(message.getPreKeyId().ForceGetValue()).getKeyPair();
BobAxolotlParameters.Builder parameters = BobAxolotlParameters.newBuilder();
parameters.setOurIdentityKey(identityKeyStore.GetIdentityKeyPair())
.setOurSignedPreKey(ourPreKey)
.setOurRatchetKey(ourPreKey)
.setOurOneTimePreKey(May<ECKeyPair>.NoValue) //absent
.setTheirIdentityKey(message.getIdentityKey())
.setTheirBaseKey(message.getBaseKey());
if (!sessionRecord.isFresh()) sessionRecord.archiveCurrentState();
RatchetingSession.initializeSession(sessionRecord.getSessionState(), message.getMessageVersion(), parameters.create());
sessionRecord.getSessionState().setLocalRegistrationId(identityKeyStore.GetLocalRegistrationId());
sessionRecord.getSessionState().setRemoteRegistrationId(message.getRegistrationId());
sessionRecord.getSessionState().setAliceBaseKey(message.getBaseKey().serialize());
if (message.getPreKeyId().ForceGetValue() != Medium.MAX_VALUE)
{
return message.getPreKeyId();
}
else
{
return May<uint>.NoValue; // May.absent();
}
}
/**
* Build a new session from a received {@link org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage}.
*
* After a session is constructed in this way, the embedded {@link org.whispersystems.libaxolotl.protocol.WhisperMessage}
* can be decrypted.
*
* @param message The received {@link org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage}.
* @throws org.whispersystems.libaxolotl.InvalidKeyIdException when there is no local
* {@link org.whispersystems.libaxolotl.state.PreKeyRecord}
* that corresponds to the PreKey ID in
* the message.
* @throws org.whispersystems.libaxolotl.InvalidKeyException when the message is formatted incorrectly.
* @throws org.whispersystems.libaxolotl.UntrustedIdentityException when the {@link IdentityKey} of the sender is untrusted.
*/
/*package*/
internal May<uint> process(SessionRecord sessionRecord, PreKeyWhisperMessage message)
{
uint messageVersion = message.getMessageVersion();
IdentityKey theirIdentityKey = message.getIdentityKey();
May<uint> unsignedPreKeyId;
if (!identityKeyStore.IsTrustedIdentity(remoteAddress.getName(), theirIdentityKey))
{
throw new UntrustedIdentityException(remoteAddress.getName(), theirIdentityKey);
}
switch (messageVersion)
{
case 2: unsignedPreKeyId = processV2(sessionRecord, message); break;
case 3: unsignedPreKeyId = processV3(sessionRecord, message); break;
default: throw new Exception("Unknown version: " + messageVersion);
}
identityKeyStore.SaveIdentity(remoteAddress.getName(), theirIdentityKey);
return unsignedPreKeyId;
}
