使用Rijndael数据加密和解密时间过长

时间:2012-10-26 00:14:19

标签: c# .net security aes rijndael

我正在尝试使用此代码进行加密和解密,但在.FlushFinalBlock()期间进行解密时,我的数据长度会持续太长。

我不确定我在这里做错了什么,因为我不在这个问题上。

谁能告诉我这里我做错了什么?加密没问题,但无法解密加密。

   static byte[] u8_Salt = new byte[] { 0x26, 0x19, 0x81, 0x4E, 0xA0, 0x6D, 0x95, 0x34, 0x26, 0x75, 0x64, 0x05, 0xF6 };

   public static string Encrypt(string data, string password)
    {
        //
        Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(password, u8_Salt);
        //
        Rijndael i_Alg = Rijndael.Create();
        i_Alg.Padding = PaddingMode.None;
        i_Alg.Key = pdb.GetBytes(32);
        i_Alg.IV = pdb.GetBytes(16);
        //
        using (var cryptoProvider = new DESCryptoServiceProvider())
        using (var memoryStream = new MemoryStream())
        using (var cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateEncryptor(), CryptoStreamMode.Write))
        using (var writer = new StreamWriter(cryptoStream))
        {
            writer.Write(data);
            writer.Flush();
            cryptoStream.FlushFinalBlock();
            writer.Flush();
            return Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);
        }
    }
    public static string Decrypt(string data, string password)
    {
        Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(password, u8_Salt);
        //
        Rijndael i_Alg = Rijndael.Create();
        i_Alg.Padding = PaddingMode.None;
        i_Alg.Key = pdb.GetBytes(32);
        i_Alg.IV = pdb.GetBytes(16);
        //
        using (var cryptoProvider = new DESCryptoServiceProvider())
        using (var memoryStream = new MemoryStream())
        using (var cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateDecryptor(), CryptoStreamMode.Write))
        using (var writer = new StreamWriter(cryptoStream))
        {
            writer.Write(data);
            writer.Flush();
            cryptoStream.FlushFinalBlock();
            writer.Flush();
            return Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);
        }
    }

1 个答案:

答案 0 :(得分:3)

您的代码存在一些问题。首先,您要创建 Rijndael(AES)对象。但是,您正在使用DESCryptoServiceProvider,这意味着您实际上使用的是DES,而不是Rijndael。因此,您还有一个问题,即您没有为算法设置密钥。下面是使用RijndaelManaged算法重写的两个函数,该算法是.NET上AES算法的托管实现。我已经测试过,您可以毫无问题地进行加密和解密。另外:不要使用那个盐值,它都在互联网上。

static byte[] u8_Salt = new byte[] { 0x26, 0x19, 0x81, 0x4E, 0xA0, 0x6D, 0x95, 0x34, 0x26, 0x75, 0x64, 0x05, 0xF6 };

public static string EncryptString(string plainText, string password)
{
    Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(password, u8_Salt);
    using (RijndaelManaged i_Alg = new RijndaelManaged { Key = pdb.GetBytes(32), IV = pdb.GetBytes(16) })
    {
        using (var memoryStream = new MemoryStream())
        using (var cryptoStream = new CryptoStream(memoryStream, i_Alg.CreateEncryptor(), CryptoStreamMode.Write))
        {
            byte[] data = Encoding.UTF8.GetBytes(plainText);
            cryptoStream.Write(data, 0, data.Length);
            cryptoStream.FlushFinalBlock();

            return Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);
        }
    }
}

public static string Decrypt(string cipherText, string password)
{
    Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(password, u8_Salt);

    using (RijndaelManaged i_Alg = new RijndaelManaged { Padding = PaddingMode.Zeros, Key = pdb.GetBytes(32), IV = pdb.GetBytes(16) })
    {
        using (var memoryStream = new MemoryStream())
        {
            using (var cryptoStream = new CryptoStream(memoryStream, i_Alg.CreateDecryptor(), CryptoStreamMode.Write))
            {
                byte[] data = Convert.FromBase64String(cipherText);
                cryptoStream.Write(data, 0, data.Length);
                cryptoStream.Flush();

                return Encoding.UTF8.GetString(memoryStream.ToArray());
            }
        }
    }
}

要生成随机盐,我会使用RNGCryptoServiceProvider这将生成一个可以使用的加密安全随机字节数组。您需要在单独的过程中生成它并将其用作盐。