/// <exception cref="IOException"></exception>
public TlsNullCipher(TlsContext context, IDigest clientWriteDigest, IDigest serverWriteDigest)
{
if ((clientWriteDigest == null) != (serverWriteDigest == null))
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
this.context = context;
TlsMac clientWriteMac = null, serverWriteMac = null;
if (clientWriteDigest != null)
{
int key_block_size = clientWriteDigest.GetDigestSize()
+ serverWriteDigest.GetDigestSize();
byte[] key_block = TlsUtilities.CalculateKeyBlock(context, key_block_size);
int offset = 0;
clientWriteMac = new TlsMac(context, clientWriteDigest, key_block, offset,
clientWriteDigest.GetDigestSize());
offset += clientWriteDigest.GetDigestSize();
serverWriteMac = new TlsMac(context, serverWriteDigest, key_block, offset,
serverWriteDigest.GetDigestSize());
offset += serverWriteDigest.GetDigestSize();
if (offset != key_block_size)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
}
if (context.IsServer)
{
writeMac = serverWriteMac;
readMac = clientWriteMac;
}
else
{
writeMac = clientWriteMac;
readMac = serverWriteMac;
}
}
/// <exception cref="IOException"></exception>
public TlsStreamCipher(TlsContext context, IStreamCipher clientWriteCipher,
IStreamCipher serverWriteCipher, IDigest clientWriteDigest, IDigest serverWriteDigest,
int cipherKeySize, bool usesNonce)
{
bool isServer = context.IsServer;
this.context = context;
this.usesNonce = usesNonce;
this.encryptCipher = clientWriteCipher;
this.decryptCipher = serverWriteCipher;
int key_block_size = (2 * cipherKeySize) + clientWriteDigest.GetDigestSize()
+ serverWriteDigest.GetDigestSize();
byte[] key_block = TlsUtilities.CalculateKeyBlock(context, key_block_size);
int offset = 0;
// Init MACs
TlsMac clientWriteMac = new TlsMac(context, clientWriteDigest, key_block, offset,
clientWriteDigest.GetDigestSize());
offset += clientWriteDigest.GetDigestSize();
TlsMac serverWriteMac = new TlsMac(context, serverWriteDigest, key_block, offset,
serverWriteDigest.GetDigestSize());
offset += serverWriteDigest.GetDigestSize();
// Build keys
KeyParameter clientWriteKey = new KeyParameter(key_block, offset, cipherKeySize);
offset += cipherKeySize;
KeyParameter serverWriteKey = new KeyParameter(key_block, offset, cipherKeySize);
offset += cipherKeySize;
if (offset != key_block_size)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
ICipherParameters encryptParams, decryptParams;
if (isServer)
{
this.writeMac = serverWriteMac;
this.readMac = clientWriteMac;
this.encryptCipher = serverWriteCipher;
this.decryptCipher = clientWriteCipher;
encryptParams = serverWriteKey;
decryptParams = clientWriteKey;
}
else
{
this.writeMac = clientWriteMac;
this.readMac = serverWriteMac;
this.encryptCipher = clientWriteCipher;
this.decryptCipher = serverWriteCipher;
encryptParams = clientWriteKey;
decryptParams = serverWriteKey;
}
if (usesNonce)
{
byte[] dummyNonce = new byte[8];
encryptParams = new ParametersWithIV(encryptParams, dummyNonce);
decryptParams = new ParametersWithIV(decryptParams, dummyNonce);
}
this.encryptCipher.Init(true, encryptParams);
this.decryptCipher.Init(false, decryptParams);
}
public TlsNullCipher(TlsContext context)
{
this.context = context;
this.writeMac = null;
this.readMac = null;
}
/// <exception cref="IOException"></exception>
public TlsBlockCipher(TlsContext context, IBlockCipher clientWriteCipher, IBlockCipher serverWriteCipher,
IDigest clientWriteDigest, IDigest serverWriteDigest, int cipherKeySize)
{
this.context = context;
this.randomData = new byte[256];
context.NonceRandomGenerator.NextBytes(randomData);
this.useExplicitIV = TlsUtilities.IsTlsV11(context);
this.encryptThenMac = context.SecurityParameters.encryptThenMac;
int key_block_size = (2 * cipherKeySize) + clientWriteDigest.GetDigestSize()
+ serverWriteDigest.GetDigestSize();
// From TLS 1.1 onwards, block ciphers don't need client_write_IV
if (!useExplicitIV)
{
key_block_size += clientWriteCipher.GetBlockSize() + serverWriteCipher.GetBlockSize();
}
byte[] key_block = TlsUtilities.CalculateKeyBlock(context, key_block_size);
int offset = 0;
TlsMac clientWriteMac = new TlsMac(context, clientWriteDigest, key_block, offset,
clientWriteDigest.GetDigestSize());
offset += clientWriteDigest.GetDigestSize();
TlsMac serverWriteMac = new TlsMac(context, serverWriteDigest, key_block, offset,
serverWriteDigest.GetDigestSize());
offset += serverWriteDigest.GetDigestSize();
KeyParameter client_write_key = new KeyParameter(key_block, offset, cipherKeySize);
offset += cipherKeySize;
KeyParameter server_write_key = new KeyParameter(key_block, offset, cipherKeySize);
offset += cipherKeySize;
byte[] client_write_IV, server_write_IV;
if (useExplicitIV)
{
client_write_IV = new byte[clientWriteCipher.GetBlockSize()];
server_write_IV = new byte[serverWriteCipher.GetBlockSize()];
}
else
{
client_write_IV = Arrays.CopyOfRange(key_block, offset, offset + clientWriteCipher.GetBlockSize());
offset += clientWriteCipher.GetBlockSize();
server_write_IV = Arrays.CopyOfRange(key_block, offset, offset + serverWriteCipher.GetBlockSize());
offset += serverWriteCipher.GetBlockSize();
}
if (offset != key_block_size)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
ICipherParameters encryptParams, decryptParams;
if (context.IsServer)
{
this.mWriteMac = serverWriteMac;
this.mReadMac = clientWriteMac;
this.encryptCipher = serverWriteCipher;
this.decryptCipher = clientWriteCipher;
encryptParams = new ParametersWithIV(server_write_key, server_write_IV);
decryptParams = new ParametersWithIV(client_write_key, client_write_IV);
}
else
{
this.mWriteMac = clientWriteMac;
this.mReadMac = serverWriteMac;
this.encryptCipher = clientWriteCipher;
this.decryptCipher = serverWriteCipher;
encryptParams = new ParametersWithIV(client_write_key, client_write_IV);
decryptParams = new ParametersWithIV(server_write_key, server_write_IV);
}
this.encryptCipher.Init(true, encryptParams);
this.decryptCipher.Init(false, decryptParams);
}