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 SendChangeCipherSpec(Session session)
{
int size = 1;
int responseSize = DTLSRecord.RECORD_OVERHEAD + size;
byte[] response = new byte[responseSize];
DTLSRecord record = new DTLSRecord
{
RecordType = TRecordType.ChangeCipherSpec,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber(),
Fragment = new byte[size]
};
record.Fragment[0] = 1;
if (session.Version != null)
{
record.Version = session.Version;
}
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
session.ChangeEpoch();
}
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
{
RecordType = TRecordType.Handshake,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber(),
Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size]
};
if (session.Version != null)
{
record.Version = session.Version;
}
HandshakeRecord handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = messageSequence,
Length = (uint)size,
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 void Send(EndPoint remoteEndPoint, byte[] data)
{
SocketAddress address = remoteEndPoint.Serialize();
Session session = _Sessions.GetSession(address);
if (session != null)
{
try
{
DTLSRecord record = new DTLSRecord
{
RecordType = TRecordType.ApplicationData,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber()
};
if (session.Version != null)
{
record.Version = session.Version;
}
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
int 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);
}
#if DEBUG
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
StackFrame callStack = new StackFrame(1, true);
Console.WriteLine($"Exception! Type: { ex.GetType()}\n\tData: { ex.Data.Count}\n\tMessage: { ex.Message}\n\tSource: { ex.Source}\n\t" +
$"StackTrace: { ex.StackTrace}\n\tFile: {callStack.GetFileName()}\n\t" +
$"Line: {callStack.GetFileLineNumber()}");
#else
catch
{
#endif
}
}
}
private void SendAlert(Session session, SocketAddress address, TAlertLevel alertLevel, TAlertDescription alertDescription)
{
#if DEBUG
Console.WriteLine($"Alert! {alertDescription}");
#endif
if (session != null)
{
DTLSRecord record = new DTLSRecord
{
RecordType = TRecordType.Alert,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber()
};
if (session.Version != null)
{
record.Version = session.Version;
}
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
byte[] data = new byte[2];
data[0] = (byte)alertLevel;
data[1] = (byte)alertDescription;
if (session.Cipher == null)
{
record.Fragment = data;
}
else
{
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
}
int 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 Send(EndPoint remoteEndPoint, byte[] data)
{
SocketAddress address = remoteEndPoint.Serialize();
Session session = _Sessions.GetSession(address);
if (session != null)
{
try
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.ApplicationData;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
if (session.Version != null)
{
record.Version = session.Version;
}
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
int 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);
}
#if DEBUG
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
#else
catch
{
#endif
}
}
}
public void ProcessHandshake(DTLSRecord record)
{
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 < 50))
{
System.Threading.Thread.Sleep(10);
count++;
}
if (session.Cipher == null)
{
throw new Exception();
}
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();
session.SessionID = Guid.NewGuid();
session.RemoteEndPoint = record.RemoteEndPoint;
session.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();
helloVerifyRequest.Cookie = cookie;
helloVerifyRequest.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();
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();
keyExchange.Curve = curve;
keyExchange.KeyExchangeAlgorithm = keyExchangeAlgorithm;
keyExchange.ClientRandom = clientHello.Random;
keyExchange.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();
keyExchange.Curve = curve;
keyExchange.KeyExchangeAlgorithm = keyExchangeAlgorithm;
keyExchange.ClientRandom = clientHello.Random;
keyExchange.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();
keyExchange.KeyExchangeAlgorithm = keyExchangeAlgorithm;
keyExchange.ClientRandom = clientHello.Random;
keyExchange.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);
}
}
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.WriteToConsole(handshakeHash);
Console.Write("Sent Verify:");
TLSUtils.WriteToConsole(finished.VerifyData);
Console.Write("Calc Verify:");
TLSUtils.WriteToConsole(calculatedVerifyData);
#endif
if (TLSUtils.ByteArrayCompare(finished.VerifyData, calculatedVerifyData))
{
SendChangeCipherSpec(session);
session.Handshake.UpdateHandshakeHash(data);
handshakeHash = session.Handshake.GetHash();
Finished serverFinished = new Finished();
serverFinished.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;
}
}
}
}
private void SendChangeCipherSpec(Session session)
{
int size = 1;
int responseSize = DTLSRecord.RECORD_OVERHEAD + size;
byte[] response = new byte[responseSize];
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.ChangeCipherSpec;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
record.Fragment = new byte[size];
record.Fragment[0] = 1;
if (session.Version != null)
record.Version = session.Version;
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
session.ChangeEpoch();
}
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;
}
}
}
}
private void SendAlert(Session session, SocketAddress address, TAlertLevel alertLevel, TAlertDescription alertDescription)
{
if (session != null)
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.Alert;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
if (session.Version != null)
record.Version = session.Version;
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
byte[] data = new byte[2];
data[0] = (byte)alertLevel;
data[1] = (byte)alertDescription;
if (session.Cipher == null)
record.Fragment = data;
else
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
int 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 (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;
}
}
}
