internal static bool TransformBuffer(CipherSuiteInfo cipher, ICryptoTransform transform, byte[] inputBuffer, int inputOffset, int inputCount, out byte[] outputBuffer)
{
outputBuffer = null;
if (inputCount % transform.InputBlockSize != 0)
{
throw new Exception("Input data size doesn't match block size");
}
int blockCount = inputCount / transform.InputBlockSize;
outputBuffer = new byte[blockCount * transform.OutputBlockSize];
if (transform.CanTransformMultipleBlocks)
{
transform.TransformBlock(inputBuffer, inputOffset, blockCount * transform.InputBlockSize, outputBuffer, 0);
}
else
{
for (int i = 0; i < blockCount; i++)
{
int input = inputOffset + i * transform.InputBlockSize;
int output = i * transform.OutputBlockSize;
transform.TransformBlock(inputBuffer, input, transform.InputBlockSize, outputBuffer, output);
}
}
// Remove IV from the beginning of the fragment if necessary?
if (cipher.CipherType == ECipherType.Block && cipher.HasExplicitIV)
{
byte[] temp = new byte[outputBuffer.Length - cipher.RecordIVLength];
Buffer.BlockCopy(outputBuffer, cipher.RecordIVLength, temp, 0, temp.Length);
outputBuffer = temp;
}
return(true);
}
public static bool VerifyMAC(CipherSuiteInfo cipher, KeyedHashAlgorithm hasher, ulong seqNum, ERecordType recordType, byte[] buffer, out byte[] bufferWithoutMac)
{
bufferWithoutMac = null;
if (cipher.CipherType == ECipherType.Stream || cipher.CipherType == ECipherType.Block)
{
if (buffer.Length < cipher.MACLength)
{
return(false);
}
bufferWithoutMac = new byte[buffer.Length - cipher.MACLength];
Buffer.BlockCopy(buffer, 0, bufferWithoutMac, 0, bufferWithoutMac.Length);
byte[] hash = CreateMAC(EProtocol.SSLv30, hasher, seqNum, recordType, bufferWithoutMac, 0);
for (int i = 1; i <= cipher.MACLength; i++)
{
if (buffer[buffer.Length - i] != hash[hash.Length - i])
{
byte[] originalMac = new byte[16];
Buffer.BlockCopy(buffer, buffer.Length - cipher.MACLength, originalMac, 0, cipher.MACLength);
throw new HttpsException($"MAC verification fail:\n{BufferFormat.AsHexString(originalMac, cipher.MACLength)}{BufferFormat.AsHexString(hash, cipher.MACLength)}");
}
}
return(true);
}
return(false);
}
public CipherKeyBlock(CipherSuiteInfo cipherSuite, PseudoRandomFunctionSSL prf)
{
ClientWriteMACKey = prf.GetBytes(cipherSuite.MACKeyLength);
ServerWriteMACKey = prf.GetBytes(cipherSuite.MACKeyLength);
ClientWriteKey = prf.GetBytes(cipherSuite.EncKeyLength);
ServerWriteKey = prf.GetBytes(cipherSuite.EncKeyLength);
ClientWriteIV = prf.GetBytes(cipherSuite.FixedIVLength);
ServerWriteIV = prf.GetBytes(cipherSuite.FixedIVLength);
}
public static bool Select(ECipherSuite[] selectFrom, out CipherSuiteInfo selected)
{
selected = null;
foreach (ECipherSuite suite in SupportedSuites.Keys)
{
if (selectFrom.Contains(suite))
{
selected = SupportedSuites[suite];
return(true);
}
}
return(false);
}
// --- Handshake Packets -------------------------------------------------------------------------------------
// -----------------------------------------------------------------------------------------------------------
private void ReceiveClientHello(ICertificateProvider certProvider, INetState ns, HttpsReader reader)
{
HttpsCmsgHello packet = new HttpsCmsgHello(reader);
if (packet.SessionID != null)
{
throw new HttpsException($"provided a sessionID (unsupported)", reader);
}
if (!SupportedCiphers.Select(packet.Ciphers, out CipherSuiteInfo cipherSelected))
{
throw new HttpsException("does not support any of our cipher suites", reader);
}
CipherSuite = cipherSelected;
_ClientRandom = packet.ClientRandom;
_ServerRandom = new byte[32];
Randoms.NextBytesUnixTimePrefix(_ServerRandom);
HttpsWriter serverHello = new HttpsSmsgHello(ns.Https, CipherSuite.CipherSuite, SessionIdentifier, _ServerRandom);
HttpsWriter serverCerts = new HttpsSmsgCertificate(ns.Https, certProvider.HttpsGetCerts());
HttpsWriter serverHelloDone = new HttpsSmsgHelloDone(ns.Https);
Send(ns, serverHello);
Send(ns, serverCerts);
Send(ns, serverHelloDone);
}
public static bool CreateMAC(CipherSuiteInfo cipher, KeyedHashAlgorithm hasher, ulong seqNum, ERecordType recordType, byte[] buffer, int offset, out byte[] mac)
{
mac = CreateMAC(EProtocol.SSLv30, hasher, seqNum, recordType, buffer, offset);
return(true);
}
private static void Add(CipherSuiteInfo info)
{
SupportedSuites[info.CipherSuite] = info;
}