private DTLSRecord CreateRecord(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
int size = handshakeMessage.CalculateSize(session.Version);
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.Handshake;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
record.Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size];
if (session.Version != null)
{
record.Version = session.Version;
}
HandshakeRecord handshakeRecord = new HandshakeRecord();
handshakeRecord.MessageType = handshakeMessage.MessageType;
handshakeRecord.MessageSeq = messageSequence;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (MemoryStream stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, session.Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
session.Handshake.UpdateHandshakeHash(record.Fragment);
}
if (session.Cipher != null)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
}
return(record);
}
private void SendHandshakeMessage(IHandshakeMessage handshakeMessage, bool encrypt)
{
int size = handshakeMessage.CalculateSize(_Version);
int maxPayloadSize = _MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
}
else
{
DTLSRecord record = new DTLSRecord
{
RecordType = TRecordType.Handshake,
Epoch = _Epoch,
SequenceNumber = NextSequenceNumber(),
Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size]
};
if (_Version != null)
{
record.Version = _Version;
}
HandshakeRecord handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = _MessageSequence
};
_MessageSequence++;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (MemoryStream stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, _Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
_HandshakeInfo.UpdateHandshakeHash(record.Fragment);
}
int responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if ((_Cipher != null) && encrypt)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = _Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = _ServerEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
}
public static HandshakeRecord Deserialise(System.IO.Stream stream)
{
HandshakeRecord result = new HandshakeRecord();
result._MessageType = (THandshakeType)stream.ReadByte();
result._Length = NetworkByteOrderConverter.ToUInt24(stream);
result._MessageSeq = NetworkByteOrderConverter.ToUInt16(stream);
result._FragmentOffset = NetworkByteOrderConverter.ToUInt24(stream);
result._FragmentLength = NetworkByteOrderConverter.ToUInt24(stream);
return(result);
}
private void SendResponse(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
int size = handshakeMessage.CalculateSize(session.Version);
int maxPayloadSize = _MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
}
else
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.Handshake;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
record.Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size];
if (session.Version != null)
{
record.Version = session.Version;
}
HandshakeRecord handshakeRecord = new HandshakeRecord();
handshakeRecord.MessageType = handshakeMessage.MessageType;
handshakeRecord.MessageSeq = messageSequence;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (MemoryStream stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, session.Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
session.Handshake.UpdateHandshakeHash(record.Fragment);
}
int responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if (session.Cipher != null)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
}
private DTLSRecord CreateRecord(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
if (session == null)
{
throw new ArgumentNullException(nameof(session));
}
if (handshakeMessage == null)
{
throw new ArgumentNullException(nameof(handshakeMessage));
}
var size = handshakeMessage.CalculateSize(session.Version);
var record = new DTLSRecord
{
RecordType = TRecordType.Handshake,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber(),
Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size]
};
if (session.Version != null)
{
record.Version = session.Version;
}
var handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = messageSequence,
Length = (uint)size,
FragmentLength = (uint)size
};
using (var stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, session.Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
session.Handshake.UpdateHandshakeHash(record.Fragment);
}
if (session.Cipher != null)
{
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
}
return(record);
}
public static HandshakeRecord Deserialise(Stream stream)
{
var result = new HandshakeRecord
{
MessageType = (THandshakeType)stream.ReadByte(),
Length = NetworkByteOrderConverter.ToUInt24(stream),
MessageSeq = NetworkByteOrderConverter.ToUInt16(stream),
FragmentOffset = NetworkByteOrderConverter.ToUInt24(stream),
FragmentLength = NetworkByteOrderConverter.ToUInt24(stream)
};
return(result);
}
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 IEnumerable <byte[]> _GetBytes(IHandshakeMessage handshakeMessage, bool encrypt)
{
if (handshakeMessage == null)
{
throw new ArgumentNullException(nameof(handshakeMessage));
}
var size = handshakeMessage.CalculateSize(this._Version);
var maxPayloadSize = _MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
var wholeMessage = new List <byte[]>();
var record = new DTLSRecord
{
RecordType = TRecordType.Handshake,
Epoch = _Epoch,
Version = this._Version
};
var handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = _MessageSequence
};
if (!(handshakeMessage.MessageType == THandshakeType.HelloVerifyRequest ||
(handshakeMessage.MessageType == THandshakeType.ClientHello && (handshakeMessage as ClientHello).Cookie == null)))
{
record.Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size];
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
handshakeRecord.FragmentOffset = 0u;
using (var stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, this._Version);
}
this._HandshakeInfo.UpdateHandshakeHash(record.Fragment);
}
var dataMessage = new byte[size];
using (var stream = new MemoryStream(dataMessage))
{
handshakeMessage.Serialise(stream, this._Version);
}
var dataMessageFragments = dataMessage.ChunkBySize(maxPayloadSize);
handshakeRecord.FragmentOffset = 0U;
dataMessageFragments.ForEach(x =>
{
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)x.Count();
record.SequenceNumber = this._NextSequenceNumber();
var baseMessage = new byte[HandshakeRecord.RECORD_OVERHEAD];
using (var stream = new MemoryStream(baseMessage))
{
handshakeRecord.Serialise(stream);
}
record.Fragment = baseMessage.Concat(x).ToArray();
var responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + x.Count();
if ((this._Cipher != null) && encrypt)
{
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = this._Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
var response = new byte[responseSize];
using (var stream = new MemoryStream(response))
{
record.Serialise(stream);
}
wholeMessage.Add(response);
handshakeRecord.FragmentOffset += (uint)x.Count();
});
this._MessageSequence++;
return(wholeMessage);
}
else
{
var record = new DTLSRecord
{
RecordType = TRecordType.Handshake,
Epoch = _Epoch,
SequenceNumber = this._NextSequenceNumber(),
Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size],
Version = this._Version
};
var handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = _MessageSequence
};
this._MessageSequence++;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (var stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, this._Version);
}
if (!(handshakeMessage.MessageType == THandshakeType.HelloVerifyRequest ||
(handshakeMessage.MessageType == THandshakeType.ClientHello && (handshakeMessage as ClientHello).Cookie == null)))
{
this._HandshakeInfo.UpdateHandshakeHash(record.Fragment);
}
var responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if ((this._Cipher != null) && encrypt)
{
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = this._Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
var response = new byte[responseSize];
using (var stream = new MemoryStream(response))
{
record.Serialise(stream);
}
return(new List <byte[]>()
{
response
});
}
}
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);
}
private DTLSRecord CreateRecord(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
int size = handshakeMessage.CalculateSize(session.Version);
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.Handshake;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
record.Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size];
if (session.Version != null)
record.Version = session.Version;
HandshakeRecord handshakeRecord = new HandshakeRecord();
handshakeRecord.MessageType = handshakeMessage.MessageType;
handshakeRecord.MessageSeq = messageSequence;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (MemoryStream stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, session.Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
session.Handshake.UpdateHandshakeHash(record.Fragment);
}
if (session.Cipher != null)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
}
return record;
}
private void SendResponse(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
int size = handshakeMessage.CalculateSize(session.Version);
int maxPayloadSize = _MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
}
else
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.Handshake;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
record.Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size];
if (session.Version != null)
record.Version = session.Version;
HandshakeRecord handshakeRecord = new HandshakeRecord();
handshakeRecord.MessageType = handshakeMessage.MessageType;
handshakeRecord.MessageSeq = messageSequence;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (MemoryStream stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, session.Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
session.Handshake.UpdateHandshakeHash(record.Fragment);
}
int responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if (session.Cipher != null)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
}
public void ProcessHandshake(DTLSRecord record)
{
#if DEBUG
Console.WriteLine($"> ProcessHandshake got {record}");
#endif
SocketAddress address = record.RemoteEndPoint.Serialize();
Session session = Sessions.GetSession(address);
byte[] data;
if ((session != null) && session.IsEncypted(record))
{
int count = 0;
while ((session.Cipher == null) && (count < (HandshakeTimeout / HANDSHAKE_DWELL_TIME)))
{
System.Threading.Thread.Sleep(HANDSHAKE_DWELL_TIME);
count++;
}
if (session.Cipher == null)
{
throw new Exception($"HandshakeTimeout: >{HandshakeTimeout}");
}
if (session.Cipher != null)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
data = session.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:
//HelloReq
break;
case THandshakeType.ClientHello:
ClientHello clientHello = ClientHello.Deserialise(stream);
if (clientHello != null)
{
byte[] cookie = clientHello.CalculateCookie(record.RemoteEndPoint, _HelloSecret);
if (clientHello.Cookie == null)
{
Version version = clientHello.ClientVersion;
if (ServerVersion < version)
{
version = ServerVersion;
}
if (session == null)
{
session = new Session
{
SessionID = Guid.NewGuid(),
RemoteEndPoint = record.RemoteEndPoint,
Version = version
};
Sessions.AddSession(address, session);
}
else
{
session.Reset();
session.Version = version;
}
session.ClientEpoch = record.Epoch;
session.ClientSequenceNumber = record.SequenceNumber;
//session.Handshake.UpdateHandshakeHash(data);
HelloVerifyRequest helloVerifyRequest = new HelloVerifyRequest
{
Cookie = cookie,
ServerVersion = ServerVersion
};
SendResponse(session, (IHandshakeMessage)helloVerifyRequest, 0);
}
else
{
if (session != null && session.Cipher != null && !session.IsEncypted(record))
{
session.Reset();
}
if (TLSUtils.ByteArrayCompare(clientHello.Cookie, cookie))
{
Version version = clientHello.ClientVersion;
if (ServerVersion < version)
{
version = ServerVersion;
}
if (clientHello.SessionID == null)
{
if (session == null)
{
session = new Session();
session.NextSequenceNumber();
session.SessionID = Guid.NewGuid();
session.RemoteEndPoint = record.RemoteEndPoint;
Sessions.AddSession(address, session);
}
}
else
{
Guid sessionID = Guid.Empty;
if (clientHello.SessionID.Length >= 16)
{
byte[] receivedSessionID = new byte[16];
Buffer.BlockCopy(clientHello.SessionID, 0, receivedSessionID, 0, 16);
sessionID = new Guid(receivedSessionID);
}
if (sessionID != Guid.Empty)
{
session = Sessions.GetSession(sessionID);
}
if (session == null)
{
//need to Find Session
session = new Session
{
SessionID = Guid.NewGuid()
};
session.NextSequenceNumber();
session.RemoteEndPoint = record.RemoteEndPoint;
Sessions.AddSession(address, session);
//session.Version = clientHello.ClientVersion;
}
}
session.Version = version;
session.Handshake.InitaliseHandshakeHash(version < DTLSRecord.Version1_2);
session.Handshake.UpdateHandshakeHash(data);
TCipherSuite cipherSuite = TCipherSuite.TLS_NULL_WITH_NULL_NULL;
foreach (TCipherSuite item in clientHello.CipherSuites)
{
if (_SupportedCipherSuites.ContainsKey(item) && CipherSuites.SupportedVersion(item, session.Version) && CipherSuites.SuiteUsable(item, PrivateKey, _PSKIdentities, _ValidatePSK != null))
{
cipherSuite = item;
break;
}
}
TKeyExchangeAlgorithm keyExchangeAlgorithm = CipherSuites.GetKeyExchangeAlgorithm(cipherSuite);
ServerHello serverHello = new ServerHello();
byte[] clientSessionID = new byte[32];
byte[] temp = session.SessionID.ToByteArray();
Buffer.BlockCopy(temp, 0, clientSessionID, 0, 16);
Buffer.BlockCopy(temp, 0, clientSessionID, 16, 16);
serverHello.SessionID = clientSessionID; // session.SessionID.ToByteArray();
serverHello.Random = new RandomData();
serverHello.Random.Generate();
serverHello.CipherSuite = (ushort)cipherSuite;
serverHello.ServerVersion = session.Version;
THashAlgorithm hash = THashAlgorithm.SHA256;
TEllipticCurve curve = TEllipticCurve.secp521r1;
if (clientHello.Extensions != null)
{
foreach (Extension extension in clientHello.Extensions)
{
if (extension.SpecifcExtension is ClientCertificateTypeExtension)
{
ClientCertificateTypeExtension clientCertificateType = extension.SpecifcExtension as ClientCertificateTypeExtension;
//TCertificateType certificateType = TCertificateType.Unknown;
//foreach (TCertificateType item in clientCertificateType.CertificateTypes)
//{
//}
//serverHello.AddExtension(new ClientCertificateTypeExtension(certificateType));
}
else if (extension.SpecifcExtension is EllipticCurvesExtension)
{
EllipticCurvesExtension ellipticCurves = extension.SpecifcExtension as EllipticCurvesExtension;
foreach (TEllipticCurve item in ellipticCurves.SupportedCurves)
{
if (EllipticCurveFactory.SupportedCurve(item))
{
curve = item;
break;
}
}
}
else if (extension.SpecifcExtension is ServerCertificateTypeExtension)
{
//serverHello.AddExtension();
}
else if (extension.SpecifcExtension is SignatureAlgorithmsExtension)
{
SignatureAlgorithmsExtension signatureAlgorithms = extension.SpecifcExtension as SignatureAlgorithmsExtension;
foreach (SignatureHashAlgorithm item in signatureAlgorithms.SupportedAlgorithms)
{
if (item.Signature == TSignatureAlgorithm.ECDSA)
{
hash = item.Hash;
break;
}
}
}
}
}
session.Handshake.CipherSuite = cipherSuite;
session.Handshake.ClientRandom = clientHello.Random;
session.Handshake.ServerRandom = serverHello.Random;
if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_ECDSA)
{
EllipticCurvePointFormatsExtension pointFormatsExtension = new EllipticCurvePointFormatsExtension();
pointFormatsExtension.SupportedPointFormats.Add(TEllipticCurvePointFormat.Uncompressed);
serverHello.AddExtension(pointFormatsExtension);
}
session.Handshake.MessageSequence = 1;
SendResponse(session, serverHello, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_ECDSA)
{
if (Certificate != null)
{
SendResponse(session, Certificate, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
}
ECDHEKeyExchange keyExchange = new ECDHEKeyExchange
{
Curve = curve,
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = clientHello.Random,
ServerRandom = serverHello.Random
};
keyExchange.GenerateEphemeralKey();
session.Handshake.KeyExchange = keyExchange;
if (session.Version == DTLSRecord.DefaultVersion)
{
hash = THashAlgorithm.SHA1;
}
ECDHEServerKeyExchange serverKeyExchange = new ECDHEServerKeyExchange(keyExchange, hash, TSignatureAlgorithm.ECDSA, PrivateKey);
SendResponse(session, serverKeyExchange, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
if (_RequireClientCertificate)
{
CertificateRequest certificateRequest = new CertificateRequest();
certificateRequest.CertificateTypes.Add(TClientCertificateType.ECDSASign);
certificateRequest.SupportedAlgorithms.Add(new SignatureHashAlgorithm()
{
Hash = THashAlgorithm.SHA256, Signature = TSignatureAlgorithm.ECDSA
});
SendResponse(session, certificateRequest, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
}
}
else if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_PSK)
{
ECDHEKeyExchange keyExchange = new ECDHEKeyExchange
{
Curve = curve,
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = clientHello.Random,
ServerRandom = serverHello.Random
};
keyExchange.GenerateEphemeralKey();
session.Handshake.KeyExchange = keyExchange;
ECDHEPSKServerKeyExchange serverKeyExchange = new ECDHEPSKServerKeyExchange(keyExchange);
SendResponse(session, serverKeyExchange, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
}
else if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.PSK)
{
PSKKeyExchange keyExchange = new PSKKeyExchange
{
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = clientHello.Random,
ServerRandom = serverHello.Random
};
session.Handshake.KeyExchange = keyExchange;
//Need to be able to hint identity?? for PSK if not hinting don't really need key exchange message
//PSKServerKeyExchange serverKeyExchange = new PSKServerKeyExchange();
//SendResponse(session, serverKeyExchange, session.Handshake.MessageSequence);
//session.Handshake.MessageSequence++;
}
SendResponse(session, new ServerHelloDone(), session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
}
}
}
break;
case THandshakeType.ServerHello:
break;
case THandshakeType.HelloVerifyRequest:
break;
case THandshakeType.Certificate:
Certificate clientCertificate = Certificate.Deserialise(stream, TCertificateType.X509);
if (clientCertificate.CertChain.Count > 0)
{
session.CertificateInfo = Certificates.GetCertificateInfo(clientCertificate.CertChain[0], TCertificateFormat.CER);
}
session.Handshake.UpdateHandshakeHash(data);
break;
case THandshakeType.ServerKeyExchange:
break;
case THandshakeType.CertificateRequest:
break;
case THandshakeType.ServerHelloDone:
break;
case THandshakeType.CertificateVerify:
CertificateVerify certificateVerify = CertificateVerify.Deserialise(stream, session.Version);
session.Handshake.UpdateHandshakeHash(data);
break;
case THandshakeType.ClientKeyExchange:
if ((session == null) || (session.Handshake.KeyExchange == null))
{
}
else
{
session.Handshake.UpdateHandshakeHash(data);
byte[] preMasterSecret = null;
if (session.Handshake.KeyExchange.KeyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_ECDSA)
{
ECDHEClientKeyExchange clientKeyExchange = ECDHEClientKeyExchange.Deserialise(stream);
if (clientKeyExchange != null)
{
ECDHEKeyExchange ecKeyExchange = session.Handshake.KeyExchange as ECDHEKeyExchange;
preMasterSecret = ecKeyExchange.GetPreMasterSecret(clientKeyExchange.PublicKeyBytes);
}
}
else if (session.Handshake.KeyExchange.KeyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_PSK)
{
ECDHEPSKClientKeyExchange clientKeyExchange = ECDHEPSKClientKeyExchange.Deserialise(stream);
if (clientKeyExchange != null)
{
session.PSKIdentity = Encoding.UTF8.GetString(clientKeyExchange.PSKIdentity);
byte[] psk = _PSKIdentities.GetKey(clientKeyExchange.PSKIdentity);
if (psk == null)
{
psk = _ValidatePSK(clientKeyExchange.PSKIdentity);
if (psk != null)
{
_PSKIdentities.AddIdentity(clientKeyExchange.PSKIdentity, psk);
}
}
if (psk != null)
{
ECDHEKeyExchange ecKeyExchange = session.Handshake.KeyExchange as ECDHEKeyExchange;
byte[] otherSecret = ecKeyExchange.GetPreMasterSecret(clientKeyExchange.PublicKeyBytes);
preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, psk);
}
}
}
else if (session.Handshake.KeyExchange.KeyExchangeAlgorithm == TKeyExchangeAlgorithm.PSK)
{
PSKClientKeyExchange clientKeyExchange = PSKClientKeyExchange.Deserialise(stream);
if (clientKeyExchange != null)
{
session.PSKIdentity = Encoding.UTF8.GetString(clientKeyExchange.PSKIdentity);
byte[] psk = _PSKIdentities.GetKey(clientKeyExchange.PSKIdentity);
if (psk == null)
{
psk = _ValidatePSK(clientKeyExchange.PSKIdentity);
if (psk != null)
{
_PSKIdentities.AddIdentity(clientKeyExchange.PSKIdentity, psk);
}
}
if (psk != null)
{
ECDHEKeyExchange ecKeyExchange = session.Handshake.KeyExchange as ECDHEKeyExchange;
byte[] otherSecret = new byte[psk.Length];
preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, psk);
}
}
}
if (preMasterSecret != null)
{
//session.MasterSecret = TLSUtils.CalculateMasterSecret(preMasterSecret, session.KeyExchange);
//TLSUtils.AssignCipher(session);
session.Cipher = TLSUtils.AssignCipher(preMasterSecret, false, session.Version, session.Handshake);
}
else
{
Console.WriteLine($"preMasterSecret is null!");
}
}
break;
case THandshakeType.Finished:
Finished finished = Finished.Deserialise(stream);
if (session != null)
{
byte[] handshakeHash = session.Handshake.GetHash();
byte[] calculatedVerifyData = TLSUtils.GetVerifyData(session.Version, session.Handshake, false, true, handshakeHash);
#if DEBUG
Console.Write($"Handshake Hash: {TLSUtils.WriteToString(handshakeHash)}");
Console.Write($"Sent Verify: {TLSUtils.WriteToString(finished.VerifyData)}");
Console.Write($"Calc Verify: {TLSUtils.WriteToString(calculatedVerifyData)}");
#endif
if (TLSUtils.ByteArrayCompare(finished.VerifyData, calculatedVerifyData))
{
SendChangeCipherSpec(session);
session.Handshake.UpdateHandshakeHash(data);
handshakeHash = session.Handshake.GetHash();
Finished serverFinished = new Finished
{
VerifyData = TLSUtils.GetVerifyData(session.Version, session.Handshake, false, false, handshakeHash)
};
SendResponse(session, serverFinished, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
}
else
{
throw new Exception();
}
}
break;
default:
break;
}
}
}
}
public static HandshakeRecord Deserialise(System.IO.Stream stream)
{
HandshakeRecord result = new HandshakeRecord();
result._MessageType = (THandshakeType)stream.ReadByte();
result._Length = NetworkByteOrderConverter.ToUInt24(stream);
result._MessageSeq = NetworkByteOrderConverter.ToUInt16(stream);
result._FragmentOffset = NetworkByteOrderConverter.ToUInt24(stream);
result._FragmentLength = NetworkByteOrderConverter.ToUInt24(stream);
return result;
}
public void ProcessHandshake(DTLSRecord record)
{
if (record == null)
{
throw new ArgumentNullException(nameof(record));
}
var address = record.RemoteEndPoint.Serialize();
var session = this.Sessions.GetSession(address);
var data = record.Fragment;
if ((session != null) && session.IsEncypted(record))
{
var count = 0;
while ((session.Cipher == null) && (count < 50))
{
System.Threading.Thread.Sleep(10);
count++;
}
if (session.Cipher == null)
{
throw new Exception("Need Cipher for Encrypted Session");
}
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
data = session.Cipher.DecodeCiphertext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
}
using (var stream = new MemoryStream(data))
{
var handshakeRecord = HandshakeRecord.Deserialise(stream);
switch (handshakeRecord.MessageType)
{
case THandshakeType.HelloRequest:
{
//HelloReq
break;
}
case THandshakeType.ClientHello:
{
var clientHello = ClientHello.Deserialise(stream);
var cookie = clientHello.CalculateCookie(record.RemoteEndPoint, this._HelloSecret);
if (clientHello.Cookie == null)
{
var vers = clientHello.ClientVersion;
if (this.ServerVersion < vers)
{
vers = this.ServerVersion;
}
if (session == null)
{
session = new Session
{
SessionID = Guid.NewGuid(),
RemoteEndPoint = record.RemoteEndPoint,
Version = vers
};
this.Sessions.AddSession(address, session);
}
else
{
session.Reset();
session.Version = vers;
}
session.ClientEpoch = record.Epoch;
session.ClientSequenceNumber = record.SequenceNumber;
var helloVerifyRequest = new HelloVerifyRequest
{
Cookie = cookie,
ServerVersion = ServerVersion
};
this.SendResponse(session, helloVerifyRequest, 0);
break;
}
if (session != null && session.Cipher != null && !session.IsEncypted(record))
{
session.Reset();
}
if (!clientHello.Cookie.SequenceEqual(cookie))
{
break;
}
var version = clientHello.ClientVersion;
if (this.ServerVersion < version)
{
version = this.ServerVersion;
}
if (clientHello.SessionID == null)
{
if (session == null)
{
session = new Session();
session.NextSequenceNumber();
session.SessionID = Guid.NewGuid();
session.RemoteEndPoint = record.RemoteEndPoint;
this.Sessions.AddSession(address, session);
}
}
else
{
if (clientHello.SessionID.Length >= 16)
{
session = this.Sessions.GetSession(new Guid(clientHello.SessionID.Take(16).ToArray()));
}
if (session == null)
{
//need to Find Session
session = new Session
{
SessionID = Guid.NewGuid()
};
session.NextSequenceNumber();
session.RemoteEndPoint = record.RemoteEndPoint;
this.Sessions.AddSession(address, session);
}
}
session.Version = version;
var cipherSuite = TCipherSuite.TLS_NULL_WITH_NULL_NULL;
foreach (TCipherSuite item in clientHello.CipherSuites)
{
if (this._SupportedCipherSuites.ContainsKey(item) && CipherSuites.SupportedVersion(item, session.Version) && CipherSuites.SuiteUsable(item, this.PrivateKey, this._PSKIdentities, this._ValidatePSK != null))
{
cipherSuite = item;
break;
}
}
var clientSessionID = new byte[32];
var temp = session.SessionID.ToByteArray();
Buffer.BlockCopy(temp, 0, clientSessionID, 0, 16);
Buffer.BlockCopy(temp, 0, clientSessionID, 16, 16);
var serverHello = new ServerHello
{
SessionID = clientSessionID, // session.SessionID.ToByteArray();
Random = new RandomData(),
CipherSuite = (ushort)cipherSuite,
ServerVersion = session.Version
};
serverHello.Random.Generate();
session.Handshake.UpdateHandshakeHash(data);
session.Handshake.CipherSuite = cipherSuite;
session.Handshake.ClientRandom = clientHello.Random;
session.Handshake.ServerRandom = serverHello.Random;
var hash = THashAlgorithm.SHA256;
var curve = TEllipticCurve.secp521r1;
if (clientHello.Extensions != null)
{
foreach (var extension in clientHello.Extensions)
{
if (extension.SpecificExtension is ClientCertificateTypeExtension)
{
var clientCertificateType = extension.SpecificExtension as ClientCertificateTypeExtension;
//TCertificateType certificateType = TCertificateType.Unknown;
//foreach (TCertificateType item in clientCertificateType.CertificateTypes)
//{
//}
//serverHello.AddExtension(new ClientCertificateTypeExtension(certificateType));
}
else if (extension.SpecificExtension is EllipticCurvesExtension)
{
var ellipticCurves = extension.SpecificExtension as EllipticCurvesExtension;
foreach (var item in ellipticCurves.SupportedCurves)
{
if (EllipticCurveFactory.SupportedCurve(item))
{
curve = item;
break;
}
}
}
else if (extension.SpecificExtension is ServerCertificateTypeExtension)
{
//serverHello.AddExtension();
}
else if (extension.SpecificExtension is SignatureAlgorithmsExtension)
{
var signatureAlgorithms = extension.SpecificExtension as SignatureAlgorithmsExtension;
foreach (var item in signatureAlgorithms.SupportedAlgorithms)
{
if (item.Signature == TSignatureAlgorithm.ECDSA)
{
hash = item.Hash;
break;
}
}
}
}
}
var keyExchangeAlgorithm = CipherSuites.GetKeyExchangeAlgorithm(cipherSuite);
if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_ECDSA)
{
var pointFormatsExtension = new EllipticCurvePointFormatsExtension();
pointFormatsExtension.SupportedPointFormats.Add(TEllipticCurvePointFormat.Uncompressed);
serverHello.AddExtension(pointFormatsExtension);
}
session.Handshake.MessageSequence = 1;
this.SendResponse(session, serverHello, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_ECDSA)
{
if (this.Certificate != null)
{
this.SendResponse(session, this.Certificate, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
}
var keyExchange = new ECDHEKeyExchange
{
Curve = curve,
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = clientHello.Random,
ServerRandom = serverHello.Random
};
keyExchange.GenerateEphemeralKey();
session.Handshake.KeyExchange = keyExchange;
if (session.Version == DTLSRecord.DefaultVersion)
{
hash = THashAlgorithm.SHA1;
}
var serverKeyExchange = new ECDHEServerKeyExchange(keyExchange, hash, TSignatureAlgorithm.ECDSA, this.PrivateKey);
this.SendResponse(session, serverKeyExchange, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
if (this._RequireClientCertificate)
{
var certificateRequest = new CertificateRequest();
certificateRequest.CertificateTypes.Add(TClientCertificateType.ECDSASign);
certificateRequest.SupportedAlgorithms.Add(new SignatureHashAlgorithm()
{
Hash = THashAlgorithm.SHA256, Signature = TSignatureAlgorithm.ECDSA
});
this.SendResponse(session, certificateRequest, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
}
}
else if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_PSK)
{
var keyExchange = new ECDHEKeyExchange
{
Curve = curve,
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = clientHello.Random,
ServerRandom = serverHello.Random
};
keyExchange.GenerateEphemeralKey();
session.Handshake.KeyExchange = keyExchange;
var serverKeyExchange = new ECDHEPSKServerKeyExchange(keyExchange);
this.SendResponse(session, serverKeyExchange, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
}
else if (keyExchangeAlgorithm == TKeyExchangeAlgorithm.PSK)
{
var keyExchange = new PSKKeyExchange
{
KeyExchangeAlgorithm = keyExchangeAlgorithm,
ClientRandom = clientHello.Random,
ServerRandom = serverHello.Random
};
session.Handshake.KeyExchange = keyExchange;
//Need to be able to hint identity?? for PSK if not hinting don't really need key exchange message
//PSKServerKeyExchange serverKeyExchange = new PSKServerKeyExchange();
//SendResponse(session, serverKeyExchange, session.Handshake.MessageSequence);
//session.Handshake.MessageSequence++;
}
this.SendResponse(session, new ServerHelloDone(), session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
break;
}
case THandshakeType.ServerHello:
{
break;
}
case THandshakeType.HelloVerifyRequest:
{
break;
}
case THandshakeType.Certificate:
{
var clientCertificate = Certificate.Deserialise(stream, TCertificateType.X509);
if (clientCertificate.CertChain.Count > 0)
{
session.CertificateInfo = Certificates.GetCertificateInfo(clientCertificate.CertChain[0], TCertificateFormat.CER);
}
session.Handshake.UpdateHandshakeHash(data);
break;
}
case THandshakeType.ServerKeyExchange:
{
break;
}
case THandshakeType.CertificateRequest:
{
break;
}
case THandshakeType.ServerHelloDone:
{
break;
}
case THandshakeType.CertificateVerify:
{
var certificateVerify = CertificateVerify.Deserialise(stream, session.Version);
session.Handshake.UpdateHandshakeHash(data);
}
break;
case THandshakeType.ClientKeyExchange:
{
if ((session == null) || (session.Handshake.KeyExchange == null))
{
break;
}
session.Handshake.UpdateHandshakeHash(data);
byte[] preMasterSecret = null;
if (session.Handshake.KeyExchange.KeyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_ECDSA)
{
var clientKeyExchange = ECDHEClientKeyExchange.Deserialise(stream);
if (clientKeyExchange != null)
{
var ecKeyExchange = session.Handshake.KeyExchange as ECDHEKeyExchange;
preMasterSecret = ecKeyExchange.GetPreMasterSecret(clientKeyExchange.PublicKeyBytes);
}
}
else if (session.Handshake.KeyExchange.KeyExchangeAlgorithm == TKeyExchangeAlgorithm.ECDHE_PSK)
{
var clientKeyExchange = ECDHEPSKClientKeyExchange.Deserialise(stream);
if (clientKeyExchange != null)
{
session.PSKIdentity = Encoding.UTF8.GetString(clientKeyExchange.PSKIdentity);
var psk = this._PSKIdentities.GetKey(clientKeyExchange.PSKIdentity);
if (psk == null)
{
psk = this._ValidatePSK(clientKeyExchange.PSKIdentity);
if (psk != null)
{
this._PSKIdentities.AddIdentity(clientKeyExchange.PSKIdentity, psk);
}
}
if (psk != null)
{
var ecKeyExchange = session.Handshake.KeyExchange as ECDHEKeyExchange;
var otherSecret = ecKeyExchange.GetPreMasterSecret(clientKeyExchange.PublicKeyBytes);
preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, psk);
}
}
}
else if (session.Handshake.KeyExchange.KeyExchangeAlgorithm == TKeyExchangeAlgorithm.PSK)
{
var clientKeyExchange = PSKClientKeyExchange.Deserialise(stream);
if (clientKeyExchange != null)
{
session.PSKIdentity = Encoding.UTF8.GetString(clientKeyExchange.PSKIdentity);
var psk = this._PSKIdentities.GetKey(clientKeyExchange.PSKIdentity);
if (psk == null)
{
psk = this._ValidatePSK(clientKeyExchange.PSKIdentity);
if (psk != null)
{
this._PSKIdentities.AddIdentity(clientKeyExchange.PSKIdentity, psk);
}
}
if (psk != null)
{
var ecKeyExchange = session.Handshake.KeyExchange as ECDHEKeyExchange;
var otherSecret = new byte[psk.Length];
preMasterSecret = TLSUtils.GetPSKPreMasterSecret(otherSecret, psk);
}
}
}
if (preMasterSecret != null)
{
//session.MasterSecret = TLSUtils.CalculateMasterSecret(preMasterSecret, session.KeyExchange);
//TLSUtils.AssignCipher(session);
session.Cipher = TLSUtils.AssignCipher(preMasterSecret, false, session.Version, session.Handshake);
}
break;
}
case THandshakeType.Finished:
{
var finished = Finished.Deserialise(stream);
if (session == null)
{
break;
}
var handshakeHash = session.Handshake.GetHash(session.Version);
var calculatedVerifyData = TLSUtils.GetVerifyData(session.Version, session.Handshake, false, true, handshakeHash);
if (!finished.VerifyData.SequenceEqual(calculatedVerifyData))
{
throw new Exception();
}
this.SendChangeCipherSpec(session);
session.Handshake.UpdateHandshakeHash(data);
handshakeHash = session.Handshake.GetHash(session.Version);
var serverFinished = new Finished
{
VerifyData = TLSUtils.GetVerifyData(session.Version, session.Handshake, false, false, handshakeHash)
};
this.SendResponse(session, serverFinished, session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
break;
}
default:
break;
}
}
}
private void SendResponse(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
if (session == null)
{
throw new ArgumentNullException(nameof(session));
}
if (handshakeMessage == null)
{
throw new ArgumentNullException(nameof(handshakeMessage));
}
var size = handshakeMessage.CalculateSize(session.Version);
var maxPayloadSize = this._MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
//fragments
return;
}
var record = new DTLSRecord
{
RecordType = TRecordType.Handshake,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber(),
Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size]
};
if (session.Version != null)
{
record.Version = session.Version;
}
var handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = messageSequence,
Length = (uint)size,
FragmentLength = (uint)size
};
using (var stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, session.Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
session.Handshake.UpdateHandshakeHash(record.Fragment);
}
var responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if (session.Cipher != null)
{
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
var response = new byte[responseSize];
using (var stream = new MemoryStream(response))
{
record.Serialise(stream);
}
var parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
this._Socket.SendToAsync(parameters);
}
