public static CipherSuite InitializeCipherSuite(byte[] master, byte[] clientrnd, byte[] serverrnd, CipherDefinition definition, ConnectionEnd entity)
{
CipherSuite ret = new CipherSuite();
SymmetricAlgorithm bulk = (SymmetricAlgorithm)Activator.CreateInstance(definition.BulkCipherAlgorithm);
if (definition.BulkIVSize > 0)
bulk.Mode = CipherMode.CBC;
bulk.Padding = PaddingMode.None;
bulk.BlockSize = definition.BulkIVSize * 8;
// get the keys and IVs
byte[] client_mac, server_mac, client_key, server_key, client_iv, server_iv;
byte[] random = new byte[64];
Array.Copy(serverrnd, 0, random, 0, 32);
Array.Copy(clientrnd, 0, random, 32, 32);
PseudoRandomDeriveBytes prf = new PseudoRandomDeriveBytes(master, "key expansion", random);
client_mac = prf.GetBytes(definition.HashSize);
server_mac = prf.GetBytes(definition.HashSize);
client_key = prf.GetBytes(definition.BulkKeySize);
server_key = prf.GetBytes(definition.BulkKeySize);
client_iv = prf.GetBytes(definition.BulkIVSize);
server_iv = prf.GetBytes(definition.BulkIVSize);
prf.Dispose();
if (definition.Exportable) { // make some extra modifications if the keys are exportable
Array.Copy(clientrnd, 0, random, 0, 32);
Array.Copy(serverrnd, 0, random, 32, 32);
prf = new PseudoRandomDeriveBytes(client_key, "client write key", random);
client_key = prf.GetBytes(definition.BulkExpandedSize);
prf.Dispose();
prf = new PseudoRandomDeriveBytes(server_key, "server write key", random);
server_key = prf.GetBytes(definition.BulkExpandedSize);
prf.Dispose();
prf = new PseudoRandomDeriveBytes(new byte[0], "IV block", random);
client_iv = prf.GetBytes(definition.BulkIVSize);
server_iv = prf.GetBytes(definition.BulkIVSize);
prf.Dispose();
}
// generate the cipher objects
if (entity == ConnectionEnd.Client) {
ret.Encryptor = bulk.CreateEncryptor(client_key, client_iv);
ret.Decryptor = bulk.CreateDecryptor(server_key, server_iv);
ret.LocalHasher = new HMAC((HashAlgorithm)Activator.CreateInstance(definition.HashAlgorithm), client_mac);
ret.RemoteHasher = new HMAC((HashAlgorithm)Activator.CreateInstance(definition.HashAlgorithm), server_mac);
} else {
ret.Encryptor = bulk.CreateEncryptor(server_key, server_iv);
ret.Decryptor = bulk.CreateDecryptor(client_key, client_iv);
ret.LocalHasher = new HMAC((HashAlgorithm)Activator.CreateInstance(definition.HashAlgorithm), server_mac);
ret.RemoteHasher = new HMAC((HashAlgorithm)Activator.CreateInstance(definition.HashAlgorithm), client_mac);
}
// clear sensitive data
Array.Clear(client_mac, 0, client_mac.Length);
Array.Clear(server_mac, 0, server_mac.Length);
Array.Clear(client_key, 0, client_key.Length);
Array.Clear(server_key, 0, server_key.Length);
Array.Clear(client_iv, 0, client_iv.Length);
Array.Clear(server_iv, 0, server_iv.Length);
Array.Clear(random, 0, random.Length);
return ret;
}
public static CipherSuite InitializeCipherSuite(byte[] master, byte[] clientrnd, byte[] serverrnd, CipherDefinition definition, ConnectionEnd entity)
{
CipherSuite ret = new CipherSuite();
SymmetricAlgorithm bulk = (SymmetricAlgorithm)Activator.CreateInstance(definition.BulkCipherAlgorithm);
if (definition.BulkIVSize > 0)
bulk.Mode = CipherMode.CBC;
bulk.Padding = PaddingMode.None;
bulk.BlockSize = definition.BulkIVSize * 8;
// get the keys and IVs
byte[] client_mac, server_mac, client_key, server_key, client_iv, server_iv;
Ssl3DeriveBytes prf = new Ssl3DeriveBytes(master, clientrnd, serverrnd, false);
client_mac = prf.GetBytes(definition.HashSize);
server_mac = prf.GetBytes(definition.HashSize);
client_key = prf.GetBytes(definition.BulkKeySize);
server_key = prf.GetBytes(definition.BulkKeySize);
client_iv = prf.GetBytes(definition.BulkIVSize);
server_iv = prf.GetBytes(definition.BulkIVSize);
prf.Dispose();
if (definition.Exportable) { // make some extra modifications if the keys are exportable
MD5 md5 = new MD5CryptoServiceProvider();
md5.TransformBlock(client_key, 0, client_key.Length, client_key, 0);
md5.TransformBlock(clientrnd, 0, clientrnd.Length, clientrnd, 0);
md5.TransformFinalBlock(serverrnd, 0, serverrnd.Length);
client_key = new byte[definition.BulkExpandedSize];
Buffer.BlockCopy(md5.Hash, 0, client_key, 0, client_key.Length);
md5.Initialize();
md5.TransformBlock(server_key, 0, server_key.Length, server_key, 0);
md5.TransformBlock(serverrnd, 0, serverrnd.Length, serverrnd, 0);
md5.TransformFinalBlock(clientrnd, 0, clientrnd.Length);
server_key = new byte[definition.BulkExpandedSize];
Buffer.BlockCopy(md5.Hash, 0, server_key, 0, server_key.Length);
md5.Initialize();
md5.TransformBlock(clientrnd, 0, clientrnd.Length, clientrnd, 0);
md5.TransformFinalBlock(serverrnd, 0, serverrnd.Length);
client_iv = new byte[definition.BulkIVSize];
Buffer.BlockCopy(md5.Hash, 0, client_iv, 0, client_iv.Length);
md5.Initialize();
md5.TransformBlock(serverrnd, 0, serverrnd.Length, serverrnd, 0);
md5.TransformFinalBlock(clientrnd, 0, clientrnd.Length);
server_iv = new byte[definition.BulkIVSize];
Buffer.BlockCopy(md5.Hash, 0, server_iv, 0, server_iv.Length);
md5.Clear();
}
// generate the cipher objects
if (entity == ConnectionEnd.Client) {
ret.Encryptor = bulk.CreateEncryptor(client_key, client_iv);
ret.Decryptor = bulk.CreateDecryptor(server_key, server_iv);
ret.LocalHasher = new Ssl3RecordMAC(definition.HashAlgorithmType, client_mac);
ret.RemoteHasher = new Ssl3RecordMAC(definition.HashAlgorithmType, server_mac);
} else {
ret.Encryptor = bulk.CreateEncryptor(server_key, server_iv);
ret.Decryptor = bulk.CreateDecryptor(client_key, client_iv);
ret.LocalHasher = new Ssl3RecordMAC(definition.HashAlgorithmType, server_mac);
ret.RemoteHasher = new Ssl3RecordMAC(definition.HashAlgorithmType, client_mac);
}
// clear sensitive data
Array.Clear(client_mac, 0, client_mac.Length);
Array.Clear(server_mac, 0, server_mac.Length);
Array.Clear(client_key, 0, client_key.Length);
Array.Clear(server_key, 0, server_key.Length);
Array.Clear(client_iv, 0, client_iv.Length);
Array.Clear(server_iv, 0, server_iv.Length);
return ret;
}
protected void GenerateCiphers(byte[] premaster)
{
byte[] clientrnd = new byte[32], serverrnd = new byte[32];
Array.Copy(m_ClientTime, 0, clientrnd, 0, 4);
Array.Copy(m_ClientRandom, 0, clientrnd, 4, 28);
Array.Copy(m_ServerTime, 0, serverrnd, 0, 4);
Array.Copy(m_ServerRandom, 0, serverrnd, 4, 28);
m_MasterSecret = GenerateMasterSecret(premaster, clientrnd, serverrnd);
m_CipherSuite = CipherSuites.GetCipherSuite(GetProtocol(), m_MasterSecret, clientrnd, serverrnd, m_EncryptionScheme, m_Options.Entity);
Array.Clear(premaster, 0, premaster.Length);
}
