C# RijndaelManaged，对于特定的输入，两组不同的密钥都可以解密

加密和解密的方法来自微软

我有两套不同的钥匙。当我使用key1加密并使用key2解密时，我希望抛出一个加密异常，但它实际上是一个乱码文本

class Program
{
    private static readonly byte[] key1 = new byte[] { 0xAC, 0x1F, 0xC4, 0x8F, 0x4C, 0x79, 0x10, 0xA1, 0x11, 0xD6, 0x7D, 0x24, 0xCE, 0x73, 0x6C, 0xE7, 0x8E, 0xD2, 0x97, 0xC2, 0x90, 0x21, 0x27, 0xE9, 0x68, 0x3F, 0x50, 0x5B, 0x92, 0x40, 0x6D, 0xC9 };
    private static readonly byte[] iv1 = new byte[] { 0xF8, 0x14, 0x77, 0xFE, 0xFC, 0x84, 0x8E, 0x66, 0x82, 0x58, 0x01, 0x6D, 0x43, 0x12, 0xD8, 0x6F };

    private static readonly byte[] key2 = new byte[] { 0x9D, 0xD8, 0x77, 0x5D, 0xA4, 0x60, 0x14, 0xFE, 0x89, 0xB6, 0xAF, 0x40, 0x2B, 0xFE, 0xE5, 0xD2, 0x0B, 0xDF, 0x55, 0x26, 0x37, 0x77, 0x6F, 0x21, 0x9A, 0x27, 0xB4, 0xD7, 0x08, 0xEA, 0xC6, 0xB9 };
    private static readonly byte[] iv2 = new byte[] { 0x4D, 0x24, 0x83, 0x94, 0x3D, 0x29, 0x86, 0x7F, 0x40, 0x3A, 0x4F, 0x87, 0x37, 0x0B, 0x11, 0x8E };

    static void Main(string[] args)
    {
        var ticks = 637375909118731913;
        string original = JsonConvert.SerializeObject(new DateTime(ticks, DateTimeKind.Utc));

        using (RijndaelManaged myRijndael = new RijndaelManaged())
        {
            byte[] encrypted = EncryptStringToBytes(original, key1, iv1);
            Console.WriteLine("Original:   {0}", original);

            string roundtrip = DecryptStringFromBytes(encrypted, key1, iv1);
            Console.WriteLine("Round Trip: {0}", roundtrip);

            try
            {
                string roundtrip2 = DecryptStringFromBytes(encrypted, key2, iv2);
                Console.WriteLine("Round Trip2: {0}", roundtrip2);
            }
            catch (CryptographicException e)
            {
                Console.WriteLine("Round Trip2: Unable to decrypt, expected.");
            }
        }
    }

    static byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
    {
        byte[] encrypted;

        using (RijndaelManaged rijAlg = new RijndaelManaged())
        {
            rijAlg.Key = Key;
            rijAlg.IV = IV;

            ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

            using (MemoryStream msEncrypt = new MemoryStream())
            {
                using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                {
                    using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                    {

                        swEncrypt.Write(plainText);
                    }
                    encrypted = msEncrypt.ToArray();
                }
            }
        }

        return encrypted;
    }

    static string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV)
    {
        string plaintext = null;

        using (RijndaelManaged rijAlg = new RijndaelManaged())
        {
            rijAlg.Key = Key;
            rijAlg.IV = IV;

            ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

            using (MemoryStream msDecrypt = new MemoryStream(cipherText))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {
                        plaintext = srDecrypt.ReadToEnd();
                    }
                }
            }
        }

        return plaintext;
    }
}

输出：

Original:   "2020-10-06T14:21:51.8731913Z"
Round Trip: "2020-10-06T14:21:51.8731913Z"
Round Trip2: 7cB?]?wV???DFI?|hgY?Q?&x

Original:   "2020-10-06T14:21:51.8731913Z"
Round Trip: "2020-10-06T14:21:51.8731913Z"
Round Trip2: Unable to decrypt, expected.

期望：

Original:   "2020-10-06T14:21:51.8731913Z"
Round Trip: "2020-10-06T14:21:51.8731913Z"
Round Trip2: 7cB?]?wV???DFI?|hgY?Q?&x

Original:   "2020-10-06T14:21:51.8731913Z"
Round Trip: "2020-10-06T14:21:51.8731913Z"
Round Trip2: Unable to decrypt, expected.

只有在特定的输入中，如果我更改ticks值，才会发生这种情况

var ticks = 637375909118731914;

一切正常

我犯了什么错误

注意：

Original:   "2020-10-06T14:21:51.8731913Z"
Round Trip: "2020-10-06T14:21:51.8731913Z"
Round Trip2: 7cB?]?wV???DFI?|hgY?Q?&x

Original:   "2020-10-06T14:21:51.8731913Z"
Round Trip: "2020-10-06T14:21:51.8731913Z"
Round Trip2: Unable to decrypt, expected.

---

有许多其他输入值可能会导致这种情况，从而在我的应用程序中导致意外错误。

我的解决方案是确定字符串是否为json格式

if(IsJson(roundtrip))
{
   Console.WriteLine("Round Trip: {0}", roundtrip);
}
else
{
   Console.WriteLine("Round Trip: Unable to decrypt.");
}

---

您正在（处理/查找）的特定加密异常是由于填充错误造成的。不幸的是，检查填充是一个非常弱的完整性检查-许多不正确的键将通过填充检查并产生垃圾。我发现了一些示例，它只捕获所有异常，但似乎并不能解决我的问题，有没有办法确定解密是否成功？@LiTang您可以在解密后可以检查的消息前面添加一些文本Rijndaelmanaged似乎没有现有的方法来检查结果，似乎我必须编写其他代码来处理此问题。