private void ProcessHandshake(DTLSRecord record)
{
byte[] data;
if (_EncyptedServerEpoch.HasValue && (_EncyptedServerEpoch.Value == record.Epoch))
{
int count = 0;
while ((_Cipher == null) && (count < 500))
{
System.Threading.Thread.Sleep(10);
count++;
}
if (_Cipher == null)
{
throw new Exception();
}
if (_Cipher != null)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
data = _Cipher.DecodeCiphertext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
}
else
{
data = record.Fragment;
}
}
else
{
data = record.Fragment;
}
using (MemoryStream stream = new MemoryStream(data))
{
HandshakeRecord handshakeRecord = HandshakeRecord.Deserialise(stream);
if (handshakeRecord != null)
{
#if DEBUG
Console.WriteLine(handshakeRecord.MessageType.ToString());
#endif
switch (handshakeRecord.MessageType)
{
case THandshakeType.HelloRequest:
break;
case THandshakeType.ClientHello:
break;
case THandshakeType.ServerHello:
ServerHello serverHello = ServerHello.Deserialise(stream);
if (serverHello != null)
{
_ServerEpoch = record.Epoch;
_HandshakeInfo.UpdateHandshakeHash(data);
_HandshakeInfo.CipherSuite = (TCipherSuite)serverHello.CipherSuite;
_HandshakeInfo.ServerRandom = serverHello.Random;
Version version = SupportedVersion;
if (serverHello.ServerVersion < version)
{
version = serverHello.ServerVersion;
}
_Version = version;
}
break;
case THandshakeType.HelloVerifyRequest:
HelloVerifyRequest helloVerifyRequest = HelloVerifyRequest.Deserialise(stream);
if (helloVerifyRequest != null)
{
_Version = helloVerifyRequest.ServerVersion;
SendHello(helloVerifyRequest.Cookie);
}
break;
case THandshakeType.Certificate:
_HandshakeInfo.UpdateHandshakeHash(data);
break;
case THandshakeType.ServerKeyExchange:
_HandshakeInfo.UpdateHandshakeHash(data);
TKeyExchangeAlgorithm keyExchangeAlgorithm = CipherSuites.GetKeyExchangeAlgorithm(_HandshakeInfo.CipherSuite);
byte[] preMasterSecret = null;
IKeyExchange keyExchange = null;
if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_ECDSA)
{
ECDHEServerKeyExchange serverKeyExchange = ECDHEServerKeyExchange.Deserialise(stream, _Version);
ECDHEKeyExchange keyExchangeECDHE = new ECDHEKeyExchange
{
CipherSuite = _HandshakeInfo.CipherSuite,
Curve = serverKeyExchange.EllipticCurve,
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = _HandshakeInfo.ClientRandom,
ServerRandom = _HandshakeInfo.ServerRandom
};
keyExchangeECDHE.GenerateEphemeralKey();
ECDHEClientKeyExchange clientKeyExchange = new ECDHEClientKeyExchange(keyExchangeECDHE.PublicKey);
_ClientKeyExchange = clientKeyExchange;
preMasterSecret = keyExchangeECDHE.GetPreMasterSecret(serverKeyExchange.PublicKeyBytes);
keyExchange = keyExchangeECDHE;
}
else if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_PSK)
{
ECDHEPSKServerKeyExchange serverKeyExchange = ECDHEPSKServerKeyExchange.Deserialise(stream, _Version);
ECDHEKeyExchange keyExchangeECDHE = new ECDHEKeyExchange
{
CipherSuite = _HandshakeInfo.CipherSuite,
Curve = serverKeyExchange.EllipticCurve,
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = _HandshakeInfo.ClientRandom,
ServerRandom = _HandshakeInfo.ServerRandom
};
keyExchangeECDHE.GenerateEphemeralKey();
ECDHEPSKClientKeyExchange clientKeyExchange = new ECDHEPSKClientKeyExchange(keyExchangeECDHE.PublicKey);
if (serverKeyExchange.PSKIdentityHint != null)
{
byte[] key = _PSKIdentities.GetKey(serverKeyExchange.PSKIdentityHint);
if (key != null)
{
_PSKIdentity = new PSKIdentity()
{
Identity = serverKeyExchange.PSKIdentityHint, Key = key
}
}
;
}
if (_PSKIdentity == null)
{
_PSKIdentity = _PSKIdentities.GetRandom();
}
clientKeyExchange.PSKIdentity = _PSKIdentity.Identity;
_ClientKeyExchange = clientKeyExchange;
byte[] otherSecret = keyExchangeECDHE.GetPreMasterSecret(serverKeyExchange.PublicKeyBytes);
preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, _PSKIdentity.Key);
keyExchange = keyExchangeECDHE;
}
else if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.PSK)
{
PSKServerKeyExchange serverKeyExchange = PSKServerKeyExchange.Deserialise(stream, _Version);
PSKClientKeyExchange clientKeyExchange = new PSKClientKeyExchange();
if (serverKeyExchange.PSKIdentityHint != null)
{
byte[] key = _PSKIdentities.GetKey(serverKeyExchange.PSKIdentityHint);
if (key != null)
{
_PSKIdentity = new PSKIdentity()
{
Identity = serverKeyExchange.PSKIdentityHint, Key = key
}
}
;
}
if (_PSKIdentity == null)
{
_PSKIdentity = _PSKIdentities.GetRandom();
}
byte[] otherSecret = new byte[_PSKIdentity.Key.Length];
clientKeyExchange.PSKIdentity = _PSKIdentity.Identity;
_ClientKeyExchange = clientKeyExchange;
preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, _PSKIdentity.Key);
}
_Cipher = TLSUtils.AssignCipher(preMasterSecret, true, _Version, _HandshakeInfo);
break;
case THandshakeType.CertificateRequest:
_HandshakeInfo.UpdateHandshakeHash(data);
_SendCertificate = true;
break;
case THandshakeType.ServerHelloDone:
_HandshakeInfo.UpdateHandshakeHash(data);
if (_Cipher == null)
{
keyExchangeAlgorithm = CipherSuites.GetKeyExchangeAlgorithm(_HandshakeInfo.CipherSuite);
if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.PSK)
{
PSKClientKeyExchange clientKeyExchange = new PSKClientKeyExchange();
_PSKIdentity = _PSKIdentities.GetRandom();
byte[] otherSecret = new byte[_PSKIdentity.Key.Length];
clientKeyExchange.PSKIdentity = _PSKIdentity.Identity;
_ClientKeyExchange = clientKeyExchange;
preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, _PSKIdentity.Key);
_Cipher = TLSUtils.AssignCipher(preMasterSecret, true, _Version, _HandshakeInfo);
}
}
if (_SendCertificate)
{
SendHandshakeMessage(_Certificate, false);
}
SendHandshakeMessage(_ClientKeyExchange, false);
if (_SendCertificate)
{
CertificateVerify certificateVerify = new CertificateVerify();
byte[] signatureHash = _HandshakeInfo.GetHash();
certificateVerify.SignatureHashAlgorithm = new SignatureHashAlgorithm()
{
Signature = TSignatureAlgorithm.ECDSA, Hash = THashAlgorithm.SHA256
};
certificateVerify.Signature = TLSUtils.Sign(_PrivateKey, true, _Version, _HandshakeInfo, certificateVerify.SignatureHashAlgorithm, signatureHash);
SendHandshakeMessage(certificateVerify, false);
}
SendChangeCipherSpec();
byte[] handshakeHash = _HandshakeInfo.GetHash();
Finished finished = new Finished
{
VerifyData = TLSUtils.GetVerifyData(_Version, _HandshakeInfo, true, true, handshakeHash)
};
SendHandshakeMessage(finished, true);
#if DEBUG
Console.Write($"Handshake Hash: {TLSUtils.WriteToString(handshakeHash)}");
Console.Write($"Sent Verify: {TLSUtils.WriteToString(finished.VerifyData)}");
#endif
break;
case THandshakeType.CertificateVerify:
break;
case THandshakeType.ClientKeyExchange:
break;
case THandshakeType.Finished:
Finished serverFinished = Finished.Deserialise(stream);
handshakeHash = _HandshakeInfo.GetHash();
byte[] calculatedVerifyData = TLSUtils.GetVerifyData(_Version, _HandshakeInfo, true, false, handshakeHash);
#if DEBUG
Console.Write("$Recieved Verify: {TLSUtils.WriteToString(serverFinished.VerifyData)}");
Console.Write($"Calc Verify: {TLSUtils.WriteToString(calculatedVerifyData)}");
#endif
if (TLSUtils.ByteArrayCompare(serverFinished.VerifyData, calculatedVerifyData))
{
#if DEBUG
Console.WriteLine("Handshake Complete");
#endif
_Connected.Set();
}
break;
default:
break;
}
}
}
}
private async Task _ProcessHandshakeAsync(DTLSRecord record)
{
if (record == null)
{
throw new ArgumentNullException(nameof(record));
}
var data = record.Fragment;
if (this._EncyptedServerEpoch == record.Epoch)
{
var count = 0;
while ((this._Cipher == null) && (count < 500))
{
await Task.Delay(10).ConfigureAwait(false);
count++;
}
if (this._Cipher == null)
{
throw new Exception("Need Cipher for Encrypted Session");
}
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
data = this._Cipher.DecodeCiphertext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
}
using (var tempStream = new MemoryStream(data))
{
var handshakeRec = HandshakeRecord.Deserialise(tempStream);
if (handshakeRec.Length > (handshakeRec.FragmentLength + handshakeRec.FragmentOffset))
{
this._IsFragment = true;
this._FragmentedRecordList.Add(data);
return;
}
else if (this._IsFragment)
{
this._FragmentedRecordList.Add(data);
data = new byte[0];
foreach (var rec in this._FragmentedRecordList)
{
data = data.Concat(rec.Skip(HandshakeRecord.RECORD_OVERHEAD)).ToArray();
}
var tempHandshakeRec = new HandshakeRecord()
{
Length = handshakeRec.Length,
MessageSeq = handshakeRec.MessageSeq,
MessageType = handshakeRec.MessageType,
FragmentLength = handshakeRec.Length,
FragmentOffset = 0
};
var tempHandshakeBytes = new byte[HandshakeRecord.RECORD_OVERHEAD];
using (var updateStream = new MemoryStream(tempHandshakeBytes))
{
tempHandshakeRec.Serialise(updateStream);
}
data = tempHandshakeBytes.Concat(data).ToArray();
}
}
using (var stream = new MemoryStream(data))
{
var handshakeRecord = HandshakeRecord.Deserialise(stream);
switch (handshakeRecord.MessageType)
{
case THandshakeType.HelloRequest:
{
break;
}
case THandshakeType.ClientHello:
{
break;
}
case THandshakeType.ServerHello:
{
var serverHello = ServerHello.Deserialise(stream);
this._HandshakeInfo.UpdateHandshakeHash(data);
this._ServerEpoch = record.Epoch;
this._HandshakeInfo.CipherSuite = (TCipherSuite)serverHello.CipherSuite;
this._HandshakeInfo.ServerRandom = serverHello.Random;
this._Version = serverHello.ServerVersion <= this._Version ? serverHello.ServerVersion : _SupportedVersion;
break;
}
case THandshakeType.HelloVerifyRequest:
{
var helloVerifyRequest = HelloVerifyRequest.Deserialise(stream);
this._Version = helloVerifyRequest.ServerVersion;
await this._SendHelloAsync(helloVerifyRequest.Cookie).ConfigureAwait(false);
break;
}
case THandshakeType.Certificate:
{
var cert = Certificate.Deserialise(stream, TCertificateType.X509);
this._HandshakeInfo.UpdateHandshakeHash(data);
this.ServerCertificate = cert.Cert;
break;
}
case THandshakeType.ServerKeyExchange:
{
this._HandshakeInfo.UpdateHandshakeHash(data);
var keyExchangeAlgorithm = CipherSuites.GetKeyExchangeAlgorithm(this._HandshakeInfo.CipherSuite);
byte[] preMasterSecret = null;
IKeyExchange keyExchange = null;
if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_ECDSA)
{
var serverKeyExchange = ECDHEServerKeyExchange.Deserialise(stream, this._Version);
var keyExchangeECDHE = new ECDHEKeyExchange
{
CipherSuite = this._HandshakeInfo.CipherSuite,
Curve = serverKeyExchange.EllipticCurve,
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = this._HandshakeInfo.ClientRandom,
ServerRandom = this._HandshakeInfo.ServerRandom
};
keyExchangeECDHE.GenerateEphemeralKey();
var clientKeyExchange = new ECDHEClientKeyExchange(keyExchangeECDHE.PublicKey);
this._ClientKeyExchange = clientKeyExchange;
preMasterSecret = keyExchangeECDHE.GetPreMasterSecret(serverKeyExchange.PublicKeyBytes);
keyExchange = keyExchangeECDHE;
}
else if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_PSK)
{
var serverKeyExchange = ECDHEPSKServerKeyExchange.Deserialise(stream);
var keyExchangeECDHE = new ECDHEKeyExchange
{
CipherSuite = this._HandshakeInfo.CipherSuite,
Curve = serverKeyExchange.EllipticCurve,
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = this._HandshakeInfo.ClientRandom,
ServerRandom = this._HandshakeInfo.ServerRandom
};
keyExchangeECDHE.GenerateEphemeralKey();
var clientKeyExchange = new ECDHEPSKClientKeyExchange(keyExchangeECDHE.PublicKey);
if (serverKeyExchange.PSKIdentityHint != null)
{
var key = this.PSKIdentities.GetKey(serverKeyExchange.PSKIdentityHint);
if (key != null)
{
this._PSKIdentity = new PSKIdentity()
{
Identity = serverKeyExchange.PSKIdentityHint, Key = key
};
}
}
if (this._PSKIdentity == null)
{
this._PSKIdentity = this.PSKIdentities.GetRandom();
}
clientKeyExchange.PSKIdentity = this._PSKIdentity.Identity;
this._ClientKeyExchange = clientKeyExchange;
var otherSecret = keyExchangeECDHE.GetPreMasterSecret(serverKeyExchange.PublicKeyBytes);
preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, this._PSKIdentity.Key);
keyExchange = keyExchangeECDHE;
}
else if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.PSK)
{
var serverKeyExchange = PSKServerKeyExchange.Deserialise(stream);
var clientKeyExchange = new PSKClientKeyExchange();
if (serverKeyExchange.PSKIdentityHint != null)
{
var key = this.PSKIdentities.GetKey(serverKeyExchange.PSKIdentityHint);
if (key != null)
{
this._PSKIdentity = new PSKIdentity()
{
Identity = serverKeyExchange.PSKIdentityHint, Key = key
};
}
}
if (this._PSKIdentity == null)
{
this._PSKIdentity = this.PSKIdentities.GetRandom();
}
var otherSecret = new byte[this._PSKIdentity.Key.Length];
clientKeyExchange.PSKIdentity = this._PSKIdentity.Identity;
this._ClientKeyExchange = clientKeyExchange;
preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, this._PSKIdentity.Key);
}
this._Cipher = TLSUtils.AssignCipher(preMasterSecret, true, this._Version, this._HandshakeInfo);
break;
}
case THandshakeType.CertificateRequest:
{
this._HandshakeInfo.UpdateHandshakeHash(data);
this._SendCertificate = true;
break;
}
case THandshakeType.ServerHelloDone:
{
this._HandshakeInfo.UpdateHandshakeHash(data);
var keyExchangeAlgorithm = CipherSuites.GetKeyExchangeAlgorithm(this._HandshakeInfo.CipherSuite);
if (this._Cipher == null)
{
if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.PSK)
{
var clientKeyExchange = new PSKClientKeyExchange();
this._PSKIdentity = this.PSKIdentities.GetRandom();
var otherSecret = new byte[this._PSKIdentity.Key.Length];
clientKeyExchange.PSKIdentity = this._PSKIdentity.Identity;
this._ClientKeyExchange = clientKeyExchange;
var preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, this._PSKIdentity.Key);
this._Cipher = TLSUtils.AssignCipher(preMasterSecret, true, this._Version, this._HandshakeInfo);
}
else if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.RSA)
{
var clientKeyExchange = new RSAClientKeyExchange();
this._ClientKeyExchange = clientKeyExchange;
var PreMasterSecret = TLSUtils.GetRsaPreMasterSecret(this._Version);
clientKeyExchange.PremasterSecret = TLSUtils.GetEncryptedRsaPreMasterSecret(this.ServerCertificate, PreMasterSecret);
this._Cipher = TLSUtils.AssignCipher(PreMasterSecret, true, this._Version, this._HandshakeInfo);
}
else
{
throw new NotImplementedException($"Key Exchange Algorithm {keyExchangeAlgorithm} Not Implemented");
}
}
if (this._SendCertificate)
{
await this._SendHandshakeMessageAsync(this._Certificate, false).ConfigureAwait(false);
}
await this._SendHandshakeMessageAsync(this._ClientKeyExchange, false).ConfigureAwait(false);
if (this._SendCertificate)
{
var signatureHashAlgorithm = new SignatureHashAlgorithm()
{
Signature = TSignatureAlgorithm.ECDSA, Hash = THashAlgorithm.SHA256
};
if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.RSA)
{
signatureHashAlgorithm = new SignatureHashAlgorithm()
{
Signature = TSignatureAlgorithm.RSA, Hash = THashAlgorithm.SHA1
};
}
var certVerify = new CertificateVerify
{
SignatureHashAlgorithm = signatureHashAlgorithm,
Signature = TLSUtils.Sign(this._PrivateKey, this._PrivateKeyRsa, true, this._Version, this._HandshakeInfo, signatureHashAlgorithm, this._HandshakeInfo.GetHash(this._Version))
};
await this._SendHandshakeMessageAsync(certVerify, false).ConfigureAwait(false);
}
await this._SendChangeCipherSpecAsync().ConfigureAwait(false);
var handshakeHash = this._HandshakeInfo.GetHash(this._Version);
var finished = new Finished
{
VerifyData = TLSUtils.GetVerifyData(this._Version, this._HandshakeInfo, true, true, handshakeHash)
};
await this._SendHandshakeMessageAsync(finished, true).ConfigureAwait(false);
break;
}
case THandshakeType.NewSessionTicket:
{
this._HandshakeInfo.UpdateHandshakeHash(data);
break;
}
case THandshakeType.CertificateVerify:
{
break;
}
case THandshakeType.ClientKeyExchange:
{
break;
}
case THandshakeType.Finished:
{
var serverFinished = Finished.Deserialise(stream);
var handshakeHash = this._HandshakeInfo.GetHash(this._Version);
var calculatedVerifyData = TLSUtils.GetVerifyData(this._Version, this._HandshakeInfo, true, false, handshakeHash);
if (serverFinished.VerifyData.SequenceEqual(calculatedVerifyData))
{
this._ConnectionComplete = true;
}
break;
}
default:
{
break;
}
}
}
this._IsFragment = false;
this._FragmentedRecordList.RemoveAll(x => true);
}