108 lines
3.6 KiB
C#
108 lines
3.6 KiB
C#
using System;
|
|
using System.Collections.Generic;
|
|
using Shadowsocks.Encryption.Exception;
|
|
|
|
namespace Shadowsocks.Encryption.Stream
|
|
{
|
|
public class StreamSodiumEncryptor
|
|
: StreamEncryptor, IDisposable
|
|
{
|
|
const int CIPHER_SALSA20 = 1;
|
|
const int CIPHER_CHACHA20 = 2;
|
|
const int CIPHER_CHACHA20_IETF = 3;
|
|
|
|
const int SODIUM_BLOCK_SIZE = 64;
|
|
|
|
protected int _encryptBytesRemaining;
|
|
protected int _decryptBytesRemaining;
|
|
protected ulong _encryptIC;
|
|
protected ulong _decryptIC;
|
|
protected byte[] _encryptBuf;
|
|
protected byte[] _decryptBuf;
|
|
|
|
public StreamSodiumEncryptor(string method, string password)
|
|
: base(method, password)
|
|
{
|
|
_encryptBuf = new byte[MAX_INPUT_SIZE + SODIUM_BLOCK_SIZE];
|
|
_decryptBuf = new byte[MAX_INPUT_SIZE + SODIUM_BLOCK_SIZE];
|
|
}
|
|
|
|
private static Dictionary<string, EncryptorInfo> _ciphers = new Dictionary<string, EncryptorInfo> {
|
|
{ "salsa20", new EncryptorInfo(32, 8, CIPHER_SALSA20) },
|
|
{ "chacha20", new EncryptorInfo(32, 8, CIPHER_CHACHA20) },
|
|
{ "chacha20-ietf", new EncryptorInfo(32, 12, CIPHER_CHACHA20_IETF) }
|
|
};
|
|
|
|
protected override Dictionary<string, EncryptorInfo> getCiphers()
|
|
{
|
|
return _ciphers;
|
|
}
|
|
|
|
public static List<string> SupportedCiphers()
|
|
{
|
|
return new List<string>(_ciphers.Keys);
|
|
}
|
|
|
|
protected override void cipherUpdate(bool isEncrypt, int length, byte[] buf, byte[] outbuf)
|
|
{
|
|
// TODO write a unidirection cipher so we don't have to if if if
|
|
int bytesRemaining;
|
|
ulong ic;
|
|
byte[] sodiumBuf;
|
|
byte[] iv;
|
|
int ret = -1;
|
|
|
|
if (isEncrypt)
|
|
{
|
|
bytesRemaining = _encryptBytesRemaining;
|
|
ic = _encryptIC;
|
|
sodiumBuf = _encryptBuf;
|
|
iv = _encryptIV;
|
|
}
|
|
else
|
|
{
|
|
bytesRemaining = _decryptBytesRemaining;
|
|
ic = _decryptIC;
|
|
sodiumBuf = _decryptBuf;
|
|
iv = _decryptIV;
|
|
}
|
|
int padding = bytesRemaining;
|
|
Buffer.BlockCopy(buf, 0, sodiumBuf, padding, length);
|
|
|
|
switch (_cipher)
|
|
{
|
|
case CIPHER_SALSA20:
|
|
ret = Sodium.crypto_stream_salsa20_xor_ic(sodiumBuf, sodiumBuf, (ulong)(padding + length), iv, ic, _key);
|
|
break;
|
|
case CIPHER_CHACHA20:
|
|
ret = Sodium.crypto_stream_chacha20_xor_ic(sodiumBuf, sodiumBuf, (ulong)(padding + length), iv, ic, _key);
|
|
break;
|
|
case CIPHER_CHACHA20_IETF:
|
|
ret = Sodium.crypto_stream_chacha20_ietf_xor_ic(sodiumBuf, sodiumBuf, (ulong)(padding + length), iv, (uint)ic, _key);
|
|
break;
|
|
}
|
|
if (ret != 0) throw new CryptoErrorException();
|
|
|
|
Buffer.BlockCopy(sodiumBuf, padding, outbuf, 0, length);
|
|
padding += length;
|
|
ic += (ulong)padding / SODIUM_BLOCK_SIZE;
|
|
bytesRemaining = padding % SODIUM_BLOCK_SIZE;
|
|
|
|
if (isEncrypt)
|
|
{
|
|
_encryptBytesRemaining = bytesRemaining;
|
|
_encryptIC = ic;
|
|
}
|
|
else
|
|
{
|
|
_decryptBytesRemaining = bytesRemaining;
|
|
_decryptIC = ic;
|
|
}
|
|
}
|
|
|
|
public override void Dispose()
|
|
{
|
|
}
|
|
}
|
|
}
|