internal byte[] EncryptIke1Data(ICryptoLibrary cryptoLibrary, Ike1Data ike1Data)
{
if (Status != MessageSessionStatusCode.inProgress)
{
throw new InvalidOperationException();
}
var decryptedMessageData = MessageEncoderDecoder.EncodeIke1DataWithPadding(cryptoLibrary, ike1Data);
var encryptedMessageData = new byte[decryptedMessageData.Length];
cryptoLibrary.ProcessAesCbcBlocks(true, _aesKey, _iv, decryptedMessageData, encryptedMessageData);
Status = MessageSessionStatusCode.encryptionDecryptionCompleted;
return(encryptedMessageData);
}
internal byte[] EncryptShortSingleMessage(ICryptoLibrary cryptoLibrary, string messageText)
{
if (Status != MessageSessionStatusCode.inProgress)
{
throw new InvalidOperationException();
}
var decryptedMessageData = MessageEncoderDecoder.EncodePlainTextMessageWithPadding_plainTextUtf8_256(cryptoLibrary, messageText);
var encryptedMessageData = new byte[decryptedMessageData.Length];
cryptoLibrary.ProcessAesCbcBlocks(true, _aesKey, _iv, decryptedMessageData, encryptedMessageData);
Status = MessageSessionStatusCode.encryptionDecryptionCompleted;
return(encryptedMessageData);
}
internal void DeriveKeys(ICryptoLibrary cryptoLibrary, byte[] sharedPingPongHmacKey, MessageStartPacket messageStart,
byte[] directChannelSharedDhSecret)
{
if (Status != MessageSessionStatusCode.created)
{
throw new InvalidOperationException();
}
BinaryProcedures.CreateBinaryWriter(out var msE, out var wE);
messageStart.GetSignedFieldsForMessageHMAC(wE, false);
wE.Write(sharedPingPongHmacKey);
_iv = cryptoLibrary.GetHashSHA256(msE.ToArray()).Take(16).ToArray();
wE.Write(directChannelSharedDhSecret);
_aesKey = cryptoLibrary.GetHashSHA256(msE.ToArray());
Status = MessageSessionStatusCode.inProgress;
}
internal static LowLevelUdpResponseScanner GetScanner(uint messageId32, InviteSession session, MessageSessionStatusCode statusCode)
{
BinaryProcedures.CreateBinaryWriter(out var ms, out var w);
w.Write((byte)PacketTypes.MessageAck);
w.Write(messageId32);
w.Write((byte)statusCode);
return(new LowLevelUdpResponseScanner
{
ResponseFirstBytes = ms.ToArray(),
OptionalFilter = (udpData) =>
{
var msgAck = Decode(udpData);
if (msgAck.MessageHMAC.Equals(
session.GetMessageHMAC(msgAck.GetSignedFieldsForMessageHMAC)
) == false)
{
return false;
}
return true;
}
});
}
