/// <summary>
/// Build a new session from a {@link org.whispersystems.libsignal.state.PreKeyBundle} retrieved from
/// a server.
/// </summary>
/// @param preKey A PreKey for the destination recipient, retrieved from a server.
/// @throws InvalidKeyException when the {@link org.whispersystems.libsignal.state.PreKeyBundle} is
/// badly formatted.
/// @throws org.whispersystems.libsignal.UntrustedIdentityException when the sender's
/// {@link IdentityKey} is not
/// trusted.
///
public void Process(PreKeyBundle preKey)
{
lock (SessionCipher.SessionLock)
{
if (!_identityKeyStore.IsTrustedIdentity(_remoteAddress, preKey.GetIdentityKey(), Direction.Sending))
{
throw new UntrustedIdentityException(_remoteAddress.Name, preKey.GetIdentityKey());
}
if (preKey.GetSignedPreKey() != null &&
!Curve.VerifySignature(preKey.GetIdentityKey().GetPublicKey(),
preKey.GetSignedPreKey().Serialize(),
preKey.GetSignedPreKeySignature()))
{
throw new InvalidKeyException("Invalid signature on device key!");
}
if (preKey.GetSignedPreKey() == null)
{
throw new InvalidKeyException("No signed prekey!");
}
SessionRecord sessionRecord = _sessionStore.LoadSession(_remoteAddress);
EcKeyPair ourBaseKey = Curve.GenerateKeyPair();
IEcPublicKey theirSignedPreKey = preKey.GetSignedPreKey();
IEcPublicKey test = preKey.GetPreKey();
May <IEcPublicKey> theirOneTimePreKey = (test == null) ? May <IEcPublicKey> .NoValue : new May <IEcPublicKey>(test);
May <uint> theirOneTimePreKeyId = theirOneTimePreKey.HasValue ? new May <uint>(preKey.GetPreKeyId()) :
May <uint> .NoValue;
AliceSignalProtocolParameters.Builder parameters = AliceSignalProtocolParameters.NewBuilder();
parameters.SetOurBaseKey(ourBaseKey)
.SetOurIdentityKey(_identityKeyStore.GetIdentityKeyPair())
.SetTheirIdentityKey(preKey.GetIdentityKey())
.SetTheirSignedPreKey(theirSignedPreKey)
.SetTheirRatchetKey(theirSignedPreKey)
.SetTheirOneTimePreKey(theirOneTimePreKey);
if (!sessionRecord.IsFresh())
{
sessionRecord.ArchiveCurrentState();
}
RatchetingSession.InitializeSession(sessionRecord.GetSessionState(), parameters.Create());
sessionRecord.GetSessionState().SetUnacknowledgedPreKeyMessage(theirOneTimePreKeyId, preKey.GetSignedPreKeyId(), ourBaseKey.GetPublicKey());
sessionRecord.GetSessionState().SetLocalRegistrationId(_identityKeyStore.GetLocalRegistrationId());
sessionRecord.GetSessionState().SetRemoteRegistrationId(preKey.GetRegistrationId());
sessionRecord.GetSessionState().SetAliceBaseKey(ourBaseKey.GetPublicKey().Serialize());
_identityKeyStore.SaveIdentity(_remoteAddress, preKey.GetIdentityKey());
_sessionStore.StoreSession(_remoteAddress, sessionRecord);
}
}
/**
* Build a new session from a {@link org.whispersystems.libaxolotl.state.PreKeyBundle} retrieved from
* a server.
*
* @param preKey A PreKey for the destination recipient, retrieved from a server.
* @throws InvalidKeyException when the {@link org.whispersystems.libaxolotl.state.PreKeyBundle} is
* badly formatted.
* @throws org.whispersystems.libaxolotl.UntrustedIdentityException when the sender's
* {@link IdentityKey} is not
* trusted.
*/
public void Process(PreKeyBundle preKey)
{
lock (SessionCipher.SESSION_LOCK)
{
if (!identityKeyStore.IsTrustedIdentity(remoteAddress.GetName(), preKey.GetIdentityKey()))
{
throw new UntrustedIdentityException(remoteAddress.GetName(), preKey.GetIdentityKey());
}
if (preKey.GetSignedPreKey() != null &&
!Curve.VerifySignature(preKey.GetIdentityKey().GetPublicKey(),
preKey.GetSignedPreKey().Serialize(),
preKey.GetSignedPreKeySignature()))
{
throw new InvalidKeyException("Invalid Signature on Device Key!");
}
if (preKey.GetSignedPreKey() == null && preKey.GetPreKey() == null)
{
throw new InvalidKeyException("Both Signed and Unsigned Prekeys are Absent!");
}
bool supportsV3 = preKey.GetSignedPreKey() != null;
SessionRecord sessionRecord = sessionStore.LoadSession(remoteAddress);
ECKeyPair ourBaseKey = Curve.GenerateKeyPair();
ECPublicKey theirSignedPreKey = supportsV3 ? preKey.GetSignedPreKey() : preKey.GetPreKey();
ECPublicKey test = preKey.GetPreKey(); // TODO: Cleanup
May <ECPublicKey> theirOneTimePreKey = (test == null) ? May <ECPublicKey> .NoValue : new May <ECPublicKey>(test);
May <uint> theirOneTimePreKeyId = theirOneTimePreKey.HasValue ? new May <uint>(preKey.GetPreKeyId()) : May <uint> .NoValue;
AliceAxolotlParameters.Builder parameters = AliceAxolotlParameters.NewBuilder();
parameters.SetOurBaseKey(ourBaseKey)
.SetOurIdentityKey(identityKeyStore.GetIdentityKeyPair())
.SetTheirIdentityKey(preKey.GetIdentityKey())
.SetTheirSignedPreKey(theirSignedPreKey)
.SetTheirRatchetKey(theirSignedPreKey)
.SetTheirOneTimePreKey(supportsV3 ? theirOneTimePreKey : May <ECPublicKey> .NoValue);
if (!sessionRecord.IsFresh())
{
sessionRecord.ArchiveCurrentState();
}
RatchetingSession.InitializeSession(sessionRecord.GetSessionState(),
supportsV3 ? (uint)3 : 2,
parameters.Create());
sessionRecord.GetSessionState().SetUnacknowledgedPreKeyMessage(theirOneTimePreKeyId, preKey.GetSignedPreKeyId(), ourBaseKey.GetPublicKey());
sessionRecord.GetSessionState().SetLocalRegistrationId(identityKeyStore.GetLocalRegistrationId());
sessionRecord.GetSessionState().SetRemoteRegistrationId(preKey.GetRegistrationId());
sessionRecord.GetSessionState().SetAliceBaseKey(ourBaseKey.GetPublicKey().Serialize());
sessionStore.StoreSession(remoteAddress, sessionRecord);
identityKeyStore.SaveIdentity(remoteAddress.GetName(), preKey.GetIdentityKey());
}
}