C# Rijndael加密

我有一个使用C#.NET Rijndael加密的示例代码，它可以解密密文“fggsuwq1gtox40dfgdfgffdfgdfgfczer3woenxtmpmn9jjc”到普通的“75.117.87.87”

我已尝试将保留方法写入加密纯文本“75.117.87.87”到“FGGSUWQ1GTOX40DFGDFGFDFGDFCzer3WOENXTMPN9JJC”，但未成功（加密文本与预期不同-，但结果如附件所示。请帮助我，谢谢

static int Main(string[] args)
    {
        Decrypt();
        Console.WriteLine("########################");
        Console.WriteLine("########################");
        Encrypt();
        Console.ReadLine();
        return 0;
    }
public static void Decrypt()
    {
        string ciphertext = "LkbsUwQ1gToX40dYXizgc0BCCCzEr3wOenxTPMN9jJC";
        string secretkey = "11111111";
        string saltkey = "thekey";

        string result =  rijndaelDecrypt(ciphertext, secretkey, saltkey);

        Console.WriteLine("Cipher text: " + ciphertext);
        Console.WriteLine("Decrypted text: " + result);
        return;
    }
public static string  rijndaelDecrypt(string ciphertext, string secretkey, string saltkey)
    {
        if (string.IsNullOrEmpty(ciphertext))
        {
            return null;
        }
        if (string.IsNullOrEmpty(secretkey))
        {
            return null;
        }

        ciphertext = "EAAAA" + ciphertext;

        RijndaelManaged rijndaelManaged = null;
        string result = null;
        try
        {
            Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(secretkey, Encoding.ASCII.GetBytes(saltkey));
            byte[] buffer = Convert.FromBase64String(ciphertext);
            MemoryStream memoryStream = new MemoryStream(buffer);
            rijndaelManaged = new RijndaelManaged();
            rijndaelManaged.Key = rfc2898DeriveBytes.GetBytes(rijndaelManaged.KeySize / 8);
            rijndaelManaged.IV = rb(memoryStream);
            ICryptoTransform transform = rijndaelManaged.CreateDecryptor(rijndaelManaged.Key, rijndaelManaged.IV);
            CryptoStream cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Read);
            StreamReader streamReader = new StreamReader(cryptoStream);
            result = streamReader.ReadToEnd();
        }
        catch (Exception)
        {
            if (rijndaelManaged != null)
            {
                rijndaelManaged.Clear();
            }
            return null;
        }
        finally
        {
            if (rijndaelManaged != null)
            {
                rijndaelManaged.Clear();
            }
        }
        return result;
    }
public static void Encrypt()
    {
        string ciphertext = "75.117.87.87";
        string secretkey = "1111111";
        string saltkey = "thekey";
        string result;
        RijndaelManaged rijndaelManaged = new RijndaelManaged();

        Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(secretkey, Encoding.ASCII.GetBytes(saltkey));

        rijndaelManaged.Key = rfc2898DeriveBytes.GetBytes(rijndaelManaged.KeySize / 8);

        byte[] buffer = EncodeToBytes(ciphertext);
        MemoryStream memoryStream = new MemoryStream(buffer);
        rijndaelManaged.IV = rfc2898DeriveBytes.GetBytes(rijndaelManaged.BlockSize / 8);
        //rijndaelManaged.IV = rb(memoryStream);

        ICryptoTransform transform = rijndaelManaged.CreateEncryptor(rijndaelManaged.Key, rijndaelManaged.IV);
        CryptoStream cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Read);
        StreamReader streamReader = new StreamReader(cryptoStream);
        result = streamReader.ReadToEnd();


        var encryptor = rijndaelManaged.CreateEncryptor(rijndaelManaged.Key, rijndaelManaged.IV);
        var msEncrypt = new MemoryStream();

        using (var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
        using (var swEncrypt = new StreamWriter(csEncrypt))
            swEncrypt.Write(result);

        result = Convert.ToBase64String(msEncrypt.ToArray());

        Console.WriteLine("Plain text: " + ciphertext);
        Console.WriteLine("Encrypted text: " + result);
        return;
    }
private static byte[] rb(Stream s)
    {
        byte[] array = new byte[4];
        if (s.Read(array, 0, array.Length) != array.Length)
        {
            return null;
        }
        byte[] array2 = new byte[BitConverter.ToInt32(array, 0)];
        if (s.Read(array2, 0, array2.Length) != array2.Length)
        {
            return null;
        }
        return array2;
    }
 private static byte[] EncodeToBytes(string str)
    {
        byte[] bytes = new byte[str.Length * sizeof(char)];
        System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);
        return bytes;
    }

---

您使用的是不同的IVs。对于解密方法，您使用的是base64解码密文：

byte[] buffer = Convert.FromBase64String(ciphertext);
MemoryStream memoryStream = new MemoryStream(buffer);
rijndaelManaged.IV = rb(memoryStream);

对于您的加密方法，您使用PBKDF2（Rfc2898DeriveBytes）从密码中派生它，当且仅当您使用随机salt构造

Rfc2898DeriveBytes

时，这是正确的方法。 或者，您可以使用

RNGCryptoServiceProvider

获得完全随机的IV

rijndaelManaged.IV = rfc2898DeriveBytes.GetBytes(rijndaelManaged.BlockSize / 8);

---

从安全角度来看，您应该使用随机salt来派生密钥/IV，并在加密时将其预编到密文中。对于解密，您应该再次将其切断（并将其用于派生解密密钥/IV）。

我在您的代码中没有看到任何试用：）我没有看到任何加密方法的尝试。当问“为什么X不工作？”时，请确保至少显示X的代码。当您解释您尝试的内容时，这会更好。@domi1819:我已经更新了加密方法和图像，谢谢您的关注！我认为问题在于Encryption methodI中的初始化向量被否决了，因为从KDF派生IV不是你要做的，因为在使用同一密钥进行加密时，你最终会得到一个静态IV。IVs应该总是用CSPRNG随机生成。@LukePark如果可以的话，我会否决你的评论，因为使用随机盐时，从KDF派生IVs是很好的。（这就是为什么我提出了关于随机盐的安全建议，你应该一直这样做）我想你误解了。我并不是说生成的IV不合适。我反对你的笼统说法“对于你的加密算法，你是从密码中推导出来的……这是正确的做法。”。这不是正确的做法，而且具有误导性。在这种情况下，在这些特定情况下，它会产生可接受的结果。但是，将代码更改为重用AES实例会立即带来问题。如果每次代码只是随机生成IV，那么不可能通过更改其他区域的代码来引入错误。更具体地说，回想一下StackOverflow的目的是帮助其他人，就像帮助OP一样。如果不太精通密码学的人阅读了您关于从与密钥相同的KDF派生IV的建议，该怎么办？非常误导。我希望你能理解我的意思，只要用一个CSPRNG就行了。