private List <byte[]> ProcessHandshakeRequest(Message message)
{
var frames = message.Frames;
var list = new List <byte[]>();
if (frames.Count != 4)
{
list.Add(MessageHeader.HandshakeResponseFailure);
list.Add(_protocol.ComputeHash(_protocol.CryptRand()));
list.Add(_protocol.ComputeHash(_protocol.CryptRand()));
_logger.Debug("Protocol handshake failed for {0}.", message.ClientId);
}
else
{
using (var rsa = new RSACryptoServiceProvider())
{
rsa.ImportParameters(_serverPublicPrivateKey);
_identity = Encoding.UTF8.GetString(rsa.Decrypt(frames[1], RSAEncryptionPadding.Pkcs1));
_clientEphemeralA = rsa.Decrypt(frames[2], RSAEncryptionPadding.Pkcs1);
_clientIpAddress = Encoding.UTF8.GetString(rsa.Decrypt(frames[3], RSAEncryptionPadding.Pkcs1));
}
_identityHash = _repository.GetIdentityKeyHashSet(_identity);
if (null == _identityHash)
{
list.Add(MessageHeader.HandshakeResponseFailure);
list.Add(_protocol.ComputeHash(_protocol.CryptRand()));
list.Add(_protocol.ComputeHash(_protocol.CryptRand()));
_logger.Debug("Protocol handshake failed for {0}.", message.ClientId);
}
else
{
_serverEphemeralB = _protocol.GetServerEphemeralB(_identityHash.Salt,
_identityHash.Verifier, _protocol.CryptRand());
_scramble = _protocol.CalculateRandomScramble(_clientEphemeralA, _serverEphemeralB);
_serverSessionKey = _protocol.ServerComputeSessionKey(_identityHash.Salt, _identityHash.Key,
_clientEphemeralA, _serverEphemeralB, _scramble);
list.Add(MessageHeader.HandshakeResponseSuccess);
using (var rsa = new RSACryptoServiceProvider())
{
rsa.ImportParameters(_clientPublicKey);
list.Add(rsa.Encrypt(_identityHash.Salt, RSAEncryptionPadding.Pkcs1));
list.Add(rsa.Encrypt(_serverEphemeralB, RSAEncryptionPadding.Pkcs1));
}
_logger.Debug("Protocol handshake completed for {0}.", message.ClientId);
}
}
return(list);
}