C＃Byte []加密

Question

我有一个Byte []字段，它是我需要加密的文件内容。没有什么特别的或花哨的，只是足以确保下一个获得它的人将无法轻易解码它。我会使用.Net Framework 4.0附带的加密，但我绝对不需要使文件比它更大。

我想过只是简单地反转数组或在末尾添加几个字节......？

如果我可以避免使阵列变得更大，那就太棒了。

有什么建议吗？

谢谢！

Answer 1

1-16个字节的添加是否有害？默认情况下，AES将使用以下方法填充：

    private static void EncryptThenDecrypt()
    {
        byte[] message; // fill with your bytes
        byte[] encMessage; // the encrypted bytes
        byte[] decMessage; // the decrypted bytes - s/b same as message
        byte[] key;
        byte[] iv;

        using (var rijndael = new RijndaelManaged())
        {
            rijndael.GenerateKey();
            rijndael.GenerateIV();
            key = rijndael.Key;
            iv = rijndael.IV;
            encMessage = EncryptBytes(rijndael, message);
        }

        using (var rijndael = new RijndaelManaged())
        {
            rijndael.Key = key;
            rijndael.IV = iv;
            decMessage = DecryptBytes(rijndael, encMessage);
        }
    }

    private static byte[] EncryptBytes(
        SymmetricAlgorithm alg,
        byte[] message)
    {
        if ((message == null) || (message.Length == 0))
        {
            return message;
        }

        if (alg == null)
        {
            throw new ArgumentNullException("alg");
        }

        using (var stream = new MemoryStream())
        using (var encryptor = alg.CreateEncryptor())
        using (var encrypt = new CryptoStream(stream, encryptor, CryptoStreamMode.Write))
        {
            encrypt.Write(message, 0, message.Length);
            encrypt.FlushFinalBlock();
            return stream.ToArray();
        }
    }

    private static byte[] DecryptBytes(
        SymmetricAlgorithm alg,
        byte[] message)
    {
        if ((message == null) || (message.Length == 0))
        {
            return message;
        }

        if (alg == null)
        {
            throw new ArgumentNullException("alg");
        }

        using (var stream = new MemoryStream())
        using (var decryptor = alg.CreateDecryptor())
        using (var encrypt = new CryptoStream(stream, decryptor, CryptoStreamMode.Write))
        {
            encrypt.Write(message, 0, message.Length);
            encrypt.FlushFinalBlock();
            return stream.ToArray();
        }
    }

Answer 2

不要发明自己的加密机制（即通过混淆安全），使用classes provided by the framework之一。