public static void ClientFinish(TlsConnection connection, int length)
{
Log.Info("Recv ClientFinish");
var sha256 = SHA256.Create();
var handshakeData = connection.HandshakeMessages.GetRange(0, connection.HandshakeMessages.Count - length - 4).ToArray();
var handshakeHash = sha256.ComputeHash(handshakeData);
var prfClient = new PseudoRandomFunction(connection.MasterSecretBytes, "client finished", handshakeHash);
byte[] clientVerifyData = prfClient.GenerateBytes(12);
byte[] data = connection.Buffer.Read(12);
for (uint i = 0; i < 12; i++)
{
if (clientVerifyData[i] != data[i])
{
Log.Error("Invalid ClientFinish!");
return;
}
}
HandshakeResponse.ServerChangeCipherSpec(connection);
connection.SendEncrypted = true;
HandshakeResponse.ServerServerFinish(connection);
}
public static void ServerServerFinish(TlsConnection connection)
{
Log.Info("Send ServerServerFinish");
var sha256 = SHA256.Create();
var handshakeHash = sha256.ComputeHash(connection.HandshakeMessages.ToArray());
var prfClient = new PseudoRandomFunction(connection.MasterSecretBytes, "server finished", handshakeHash);
byte[] servVerData = prfClient.GenerateBytes(12);
TlsResponse.Handshake(connection, 20, ref servVerData);
}
public void InitCipher()
{
byte[] preMasterSecretBytes = PreMasterSecret.ToByteArrayUnsigned();
var prf = new PseudoRandomFunction(preMasterSecretBytes, "master secret", ClientRandom.Concat(ServerRandom));
MasterSecretBytes = prf.GenerateBytes(48);
prf = new PseudoRandomFunction(MasterSecretBytes, "key expansion", ServerRandom.Concat(ClientRandom));
byte[] keyBlock = prf.GenerateBytes(72);
using (var memoryStream = new MemoryStream(keyBlock))
{
using (var reader = new BinaryReader(memoryStream))
{
ClientWriteMacKey = reader.ReadBytes(20);
ServerWriteMacKey = reader.ReadBytes(20);
ClientWriteKey = reader.ReadBytes(16);
ServerWriteKey = reader.ReadBytes(16);
}
}
}