//修改key or iv后需调用。
private void Reset()
{
if (MbedTLS.cipher_reset(_ctx) != 0)
{
throw new EncryptorException("Cannot finalize mbed TLS cipher context.");
}
Finished = true;
}
public void InitCipher(byte[] key, byte[] iv, bool isCipher)
{
IntPtr ctx = Marshal.AllocHGlobal(MbedTLS.cipher_get_size_ex());
if (isCipher)
{
_encryptIV = iv;
_encryptCtx = ctx;
}
else
{
_decryptIV = iv;
_decryptCtx = ctx;
}
byte[] realkey = key;
if (Method == "rc4-md5")
{
byte[] temp = new byte[KeySize + IVSize];
//realkey = new byte[KeySize];
Array.Copy(key, 0, temp, 0, KeySize);
Array.Copy(iv, 0, temp, KeySize, IVSize);
realkey = MbedTLS.MD5(temp);
}
Key = realkey;
MbedTLS.cipher_init(ctx);
if (MbedTLS.cipher_setup(ctx, MbedTLS.cipher_info_from_string(FormalName)) != 0)
{
throw new EncryptorException("Cannot initialize mbed TLS cipher context.");
}
if (MbedTLS.cipher_setkey(ctx, realkey, KeySize * 8, isCipher ? MbedTLS.MbedTLS_Encrypt :
MbedTLS.MbedTLS_Decrypt) != 0)
{
throw new EncryptorException("Cannot set mbed TLS cipher key.");
}
if (MbedTLS.cipher_set_iv(ctx, iv, IVSize) != 0)
{
throw new EncryptorException("Cannot set mbed TLS cipher IV.");
}
if (MbedTLS.cipher_reset(ctx) != 0)
{
throw new EncryptorException("Cannot finalize mbed TLS cipher context.");
}
}