add AEAD support

2017-03-31 21:36:45 +08:00
parent 317c64f47e
commit 3de14098d7
20 changed files with 1354 additions and 589 deletions
@@ -0,0 +1,156 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using Shadowsocks.Encryption.Exception;
+
+namespace Shadowsocks.Encryption.Stream
+{
+    public class StreamMbedTLSEncryptor
+        : StreamEncryptor, IDisposable
+    {
+        const int CIPHER_RC4 = 1;
+        const int CIPHER_AES = 2;
+        const int CIPHER_BLOWFISH = 3;
+        const int CIPHER_CAMELLIA = 4;
+
+        private IntPtr _encryptCtx = IntPtr.Zero;
+        private IntPtr _decryptCtx = IntPtr.Zero;
+
+        public StreamMbedTLSEncryptor(string method, string password)
+            : base(method, password)
+        {
+        }
+
+        private static Dictionary<string, EncryptorInfo> _ciphers = new Dictionary<string, EncryptorInfo> {
+            { "aes-128-cfb", new EncryptorInfo("AES-128-CFB128", 16, 16, CIPHER_AES) },
+            { "aes-192-cfb", new EncryptorInfo("AES-192-CFB128", 24, 16, CIPHER_AES) },
+            { "aes-256-cfb", new EncryptorInfo("AES-256-CFB128", 32, 16, CIPHER_AES) },
+            { "aes-128-ctr", new EncryptorInfo("AES-128-CTR", 16, 16, CIPHER_AES) },
+            { "aes-192-ctr", new EncryptorInfo("AES-192-CTR", 24, 16, CIPHER_AES) },
+            { "aes-256-ctr", new EncryptorInfo("AES-256-CTR", 32, 16, CIPHER_AES) },
+            { "bf-cfb", new EncryptorInfo("BLOWFISH-CFB64", 16, 8, CIPHER_BLOWFISH) },
+            { "camellia-128-cfb", new EncryptorInfo("CAMELLIA-128-CFB128", 16, 16, CIPHER_CAMELLIA) },
+            { "camellia-192-cfb", new EncryptorInfo("CAMELLIA-192-CFB128", 24, 16, CIPHER_CAMELLIA) },
+            { "camellia-256-cfb", new EncryptorInfo("CAMELLIA-256-CFB128", 32, 16, CIPHER_CAMELLIA) },
+            { "rc4-md5", new EncryptorInfo("ARC4-128", 16, 16, CIPHER_RC4) }
+        };
+
+        public static List<string> SupportedCiphers()
+        {
+            return new List<string>(_ciphers.Keys);
+        }
+
+        protected override Dictionary<string, EncryptorInfo> getCiphers()
+        {
+            return _ciphers;
+        }
+
+        protected override void initCipher(byte[] iv, bool isEncrypt)
+        {
+            base.initCipher(iv, isEncrypt);
+            IntPtr ctx = Marshal.AllocHGlobal(MbedTLS.cipher_get_size_ex());
+            if (isEncrypt)
+            {
+                _encryptCtx = ctx;
+            }
+            else
+            {
+                _decryptCtx = ctx;
+            }
+            byte[] realkey;
+            if (_method == "rc4-md5")
+            {
+                byte[] temp = new byte[keyLen + ivLen];
+                realkey = new byte[keyLen];
+                Array.Copy(_key, 0, temp, 0, keyLen);
+                Array.Copy(iv, 0, temp, keyLen, ivLen);
+                realkey = MbedTLS.MD5(temp);
+            }
+            else
+            {
+                realkey = _key;
+            }
+            MbedTLS.cipher_init(ctx);
+            if (MbedTLS.cipher_setup( ctx, MbedTLS.cipher_info_from_string( _innerLibName ) ) != 0 )
+                throw new System.Exception("Cannot initialize mbed TLS cipher context");
+            /*
+             * MbedTLS takes key length by bit
+             * cipher_setkey() will set the correct key schedule
+             * and operation
+             *
+             *  MBEDTLS_AES_{EN,DE}CRYPT
+             *  == MBEDTLS_BLOWFISH_{EN,DE}CRYPT
+             *  == MBEDTLS_CAMELLIA_{EN,DE}CRYPT
+             *  == MBEDTLS_{EN,DE}CRYPT
+             *  
+             */
+            if (MbedTLS.cipher_setkey(ctx, realkey, keyLen * 8,
+                isEncrypt ? MbedTLS.MBEDTLS_ENCRYPT : MbedTLS.MBEDTLS_DECRYPT) != 0 )
+                throw new System.Exception("Cannot set mbed TLS cipher key");
+            if (MbedTLS.cipher_set_iv(ctx, iv, ivLen) != 0)
+                throw new System.Exception("Cannot set mbed TLS cipher IV");
+            if (MbedTLS.cipher_reset(ctx) != 0)
+                throw new System.Exception("Cannot finalize mbed TLS cipher context");
+        }
+
+        protected override void cipherUpdate(bool isEncrypt, int length, byte[] buf, byte[] outbuf)
+        {
+            // C# could be multi-threaded
+            if (_disposed)
+            {
+                throw new ObjectDisposedException(this.ToString());
+            }
+            if (MbedTLS.cipher_update(isEncrypt ? _encryptCtx : _decryptCtx,
+                buf, length, outbuf, ref length) != 0 )
+                throw new CryptoErrorException();
+        }
+
+        #region IDisposable
+
+        private bool _disposed;
+
+        // instance based lock
+        private readonly object _lock = new object();
+
+        public override void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        ~StreamMbedTLSEncryptor()
+        {
+            Dispose(false);
+        }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            lock (_lock)
+            {
+                if (_disposed) return;
+                _disposed = true;
+            }
+
+            if (disposing)
+            {
+                // free managed objects
+            }
+
+            // free unmanaged objects
+            if (_encryptCtx != IntPtr.Zero)
+            {
+                MbedTLS.cipher_free(_encryptCtx);
+                Marshal.FreeHGlobal(_encryptCtx);
+                _encryptCtx = IntPtr.Zero;
+            }
+            if (_decryptCtx != IntPtr.Zero)
+            {
+                MbedTLS.cipher_free(_decryptCtx);
+                Marshal.FreeHGlobal(_decryptCtx);
+                _decryptCtx = IntPtr.Zero;
+            }
+        }
+
+        #endregion
+    }
+}