public byte[] Decrypt(byte[] senderKeyMessageBytes, IDecryptionCallback callback)
{
lock(LOCK)
{
try
{
var record = _senderKeyStore.LoadSenderKey(_senderKeyId);
if(record.IsEmpty)
{
throw new Exception("No sender key for: " + _senderKeyId);
}
var senderKeyMessage = new SenderKeyMessage(senderKeyMessageBytes);
var senderKeyState = record.GetSenderKeyState(senderKeyMessage.KeyId);
senderKeyMessage.VerifySignature(senderKeyState.SigningKeyPublic);
var senderKey = GetSenderKey(senderKeyState, senderKeyMessage.Iteration);
byte[] plaintext = GetPlainText(senderKey.Iv, senderKey.CipherKey, senderKeyMessage.CipherText);
callback.HandlePlaintext(plaintext);
_senderKeyStore.StoreSenderKey(_senderKeyId, record);
return plaintext;
}
catch(Exception e)
{
throw new InvalidMessageException(e);
}
}
}
public byte[] Decrypt(PreKeyWhisperMessage ciphertext, IDecryptionCallback callback)
{
lock(SESSION_LOCK)
{
SessionRecord sessionRecord = _sessionStore.LoadSession(_remoteAddress);
Maybe<UInt32> unsignedPreKeyId = _sessionBuilder.Process(sessionRecord, ciphertext);
byte[] plaintext = Decrypt(sessionRecord, ciphertext.Message);
callback.HandlePlaintext(plaintext);
_sessionStore.StoreSession(_remoteAddress, sessionRecord);
if(unsignedPreKeyId.HasValue)
{
_preKeyStore.RemovePreKey(unsignedPreKeyId.Value);
}
return plaintext;
}
}
/**
* Decrypt a message.
*
* @param ciphertext The {@link PreKeySignalMessage} to decrypt.
* @param callback A callback that is triggered after decryption is complete,
* but before the updated session state has been committed to the session
* DB. This allows some implementations to store the committed plaintext
* to a DB first, in case they are concerned with a crash happening between
* the time the session state is updated but before they're able to store
* the plaintext to disk.
*
* @return The plaintext.
* @throws InvalidMessageException if the input is not valid ciphertext.
* @throws DuplicateMessageException if the input is a message that has already been received.
* @throws LegacyMessageException if the input is a message formatted by a protocol version that
* is no longer supported.
* @throws InvalidKeyIdException when there is no local {@link org.whispersystems.libsignal.state.PreKeyRecord}
* that corresponds to the PreKey ID in the message.
* @throws InvalidKeyException when the message is formatted incorrectly.
* @throws UntrustedIdentityException when the {@link IdentityKey} of the sender is untrusted.
*/
public byte[] Decrypt(PreKeySignalMessage ciphertext, IDecryptionCallback callback)
{
lock (SessionLock)
{
SessionRecord sessionRecord = _sessionStore.LoadSession(_remoteAddress);
May <uint> unsignedPreKeyId = _sessionBuilder.Process(sessionRecord, ciphertext);
byte[] plaintext = Decrypt(sessionRecord, ciphertext.GetSignalMessage());
_identityKeyStore.SaveIdentity(_remoteAddress, sessionRecord.GetSessionState().GetRemoteIdentityKey());
callback.HandlePlaintext(plaintext);
_sessionStore.StoreSession(_remoteAddress, sessionRecord);
if (unsignedPreKeyId.HasValue)
{
_preKeyStore.RemovePreKey(unsignedPreKeyId.ForceGetValue());
}
return(plaintext);
}
}
/**
* Decrypt a message.
*
* @param ciphertext The {@link SignalMessage} to decrypt.
* @param callback A callback that is triggered after decryption is complete,
* but before the updated session state has been committed to the session
* DB. This allows some implementations to store the committed plaintext
* to a DB first, in case they are concerned with a crash happening between
* the time the session state is updated but before they're able to store
* the plaintext to disk.
*
* @return The plaintext.
* @throws InvalidMessageException if the input is not valid ciphertext.
* @throws DuplicateMessageException if the input is a message that has already been received.
* @throws LegacyMessageException if the input is a message formatted by a protocol version that
* is no longer supported.
* @throws NoSessionException if there is no established session for this contact.
*/
public byte[] Decrypt(SignalMessage ciphertext, IDecryptionCallback callback)
{
lock (SessionLock)
{
if (!_sessionStore.ContainsSession(_remoteAddress))
{
throw new NoSessionException($"No session for: {_remoteAddress}");
}
SessionRecord sessionRecord = _sessionStore.LoadSession(_remoteAddress);
byte[] plaintext = Decrypt(sessionRecord, ciphertext);
if (!_identityKeyStore.IsTrustedIdentity(_remoteAddress, sessionRecord.GetSessionState().GetRemoteIdentityKey(), Direction.Receiving))
{
throw new UntrustedIdentityException(_remoteAddress.Name, sessionRecord.GetSessionState().GetRemoteIdentityKey());
}
callback.HandlePlaintext(plaintext);
_sessionStore.StoreSession(_remoteAddress, sessionRecord);
return(plaintext);
}
}
public byte[] Decrypt(WhisperMessage ciphertext, IDecryptionCallback callback)
{
lock(SESSION_LOCK)
{
if(!_sessionStore.ContainsSession(_remoteAddress))
{
throw new NoSessionException("No session for: " + _remoteAddress);
}
SessionRecord sessionRecord = _sessionStore.LoadSession(_remoteAddress);
byte[] plaintext = Decrypt(sessionRecord, ciphertext);
callback.HandlePlaintext(plaintext);
_sessionStore.StoreSession(_remoteAddress, sessionRecord);
return plaintext;
}
}