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 byte[] GenerateMasterSecret(byte[] premaster, byte[] clientRandom, byte[] serverRandom)
{
byte[] random = new byte[64];
Array.Copy(clientRandom, 0, random, 0, 32);
Array.Copy(serverRandom, 0, random, 32, 32);
PseudoRandomDeriveBytes prf = new PseudoRandomDeriveBytes(premaster, "master secret", random);
random = prf.GetBytes(48);
prf.Dispose();
return random;
}
public static byte[] GenerateMasterSecret(byte[] premaster, byte[] clientRandom, byte[] serverRandom)
{
byte[] random = new byte[64];
Array.Copy(clientRandom, 0, random, 0, 32);
Array.Copy(serverRandom, 0, random, 32, 32);
PseudoRandomDeriveBytes prf = new PseudoRandomDeriveBytes(premaster, "master secret", random);
random = prf.GetBytes(48);
prf.Dispose();
return(random);
}
protected override byte[] GetFinishedMessage() {
byte[] temp, hash = new byte[36];
m_LocalMD5Hash.TransformFinalBlock(new byte[0], 0, 0);
m_LocalSHA1Hash.TransformFinalBlock(new byte[0], 0, 0);
Array.Copy(m_LocalMD5Hash.Hash, 0, hash, 0, 16);
Array.Copy(m_LocalSHA1Hash.Hash, 0, hash, 16, 20);
PseudoRandomDeriveBytes prf = new PseudoRandomDeriveBytes(m_MasterSecret, "server finished", hash);
HandshakeMessage hm = new HandshakeMessage(HandshakeType.Finished, prf.GetBytes(12));
temp = hm.ToBytes();
prf.Dispose();
return temp;
}
protected override byte[] GetFinishedMessage() {
HandshakeMessage hm = new HandshakeMessage(HandshakeType.Finished, null);
byte[] hash = new byte[36];
m_LocalMD5Hash.TransformFinalBlock(new byte[0], 0, 0);
m_LocalSHA1Hash.TransformFinalBlock(new byte[0], 0, 0);
Array.Copy(m_LocalMD5Hash.Hash, 0, hash, 0, 16);
Array.Copy(m_LocalSHA1Hash.Hash, 0, hash, 16, 20);
PseudoRandomDeriveBytes prf = new PseudoRandomDeriveBytes(m_MasterSecret, "client finished", hash);
hm.fragment = prf.GetBytes(12);
prf.Dispose();
return hm.ToBytes();
}
protected override byte[] GetFinishedMessage()
{
byte[] temp, hash = new byte[36];
m_LocalMD5Hash.TransformFinalBlock(new byte[0], 0, 0);
m_LocalSHA1Hash.TransformFinalBlock(new byte[0], 0, 0);
Array.Copy(m_LocalMD5Hash.Hash, 0, hash, 0, 16);
Array.Copy(m_LocalSHA1Hash.Hash, 0, hash, 16, 20);
PseudoRandomDeriveBytes prf = new PseudoRandomDeriveBytes(m_MasterSecret, "server finished", hash);
HandshakeMessage hm = new HandshakeMessage(HandshakeType.Finished, prf.GetBytes(12));
temp = hm.ToBytes();
prf.Dispose();
return(temp);
}
protected override byte[] GetFinishedMessage()
{
HandshakeMessage hm = new HandshakeMessage(HandshakeType.Finished, null);
byte[] hash = new byte[36];
m_LocalMD5Hash.TransformFinalBlock(new byte[0], 0, 0);
m_LocalSHA1Hash.TransformFinalBlock(new byte[0], 0, 0);
Array.Copy(m_LocalMD5Hash.Hash, 0, hash, 0, 16);
Array.Copy(m_LocalSHA1Hash.Hash, 0, hash, 16, 20);
PseudoRandomDeriveBytes prf = new PseudoRandomDeriveBytes(m_MasterSecret, "client finished", hash);
hm.fragment = prf.GetBytes(12);
prf.Dispose();
return(hm.ToBytes());
}
protected override void VerifyFinishedMessage(byte[] peerFinished)
{
if (peerFinished.Length != 12)
{
throw new SslException(AlertDescription.IllegalParameter, "The ServerHelloDone message is invalid.");
}
byte[] hash = new byte[36];
m_RemoteMD5Hash.TransformFinalBlock(new byte[0], 0, 0);
m_RemoteSHA1Hash.TransformFinalBlock(new byte[0], 0, 0);
Array.Copy(m_RemoteMD5Hash.Hash, 0, hash, 0, 16);
Array.Copy(m_RemoteSHA1Hash.Hash, 0, hash, 16, 20);
PseudoRandomDeriveBytes prf = new PseudoRandomDeriveBytes(m_MasterSecret, "server finished", hash);
byte[] prfBytes = prf.GetBytes(12);
prf.Dispose();
for (int i = 0; i < prfBytes.Length; i++)
{
if (prfBytes[i] != peerFinished[i])
{
throw new SslException(AlertDescription.HandshakeFailure, "The computed hash verification does not correspond with the one of the client.");
}
}
}
protected override void VerifyFinishedMessage(byte[] peerFinished)
{
if (peerFinished.Length != 12)
throw new SslException(AlertDescription.IllegalParameter, "The ServerHelloDone message is invalid.");
byte[] hash = new byte[36];
m_RemoteMD5Hash.TransformFinalBlock(new byte[0], 0, 0);
m_RemoteSHA1Hash.TransformFinalBlock(new byte[0], 0, 0);
Buffer.BlockCopy(m_RemoteMD5Hash.Hash, 0, hash, 0, 16);
Buffer.BlockCopy(m_RemoteSHA1Hash.Hash, 0, hash, 16, 20);
PseudoRandomDeriveBytes prf = new PseudoRandomDeriveBytes(m_MasterSecret, "server finished", hash);
byte[] prfBytes = prf.GetBytes(12);
prf.Dispose();
for(int i = 0; i < prfBytes.Length; i++) {
if (prfBytes[i] != peerFinished[i])
throw new SslException(AlertDescription.HandshakeFailure, "The computed hash verification does not correspond with the one of the client.");
}
}
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 Org.Mentalis.Security.Cryptography.HMAC((HashAlgorithm)Activator.CreateInstance(definition.HashAlgorithm), client_mac);
ret.RemoteHasher = new Org.Mentalis.Security.Cryptography.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 Org.Mentalis.Security.Cryptography.HMAC((HashAlgorithm)Activator.CreateInstance(definition.HashAlgorithm), server_mac);
ret.RemoteHasher = new Org.Mentalis.Security.Cryptography.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);
}