Question

我正在写关于加密问题的报告。使用RijndaelManaged中的System.Security.Cryptography类会发生此问题。对于我来说，使用RijndaelManaged和CFB-8（FeedbackSize = 8）模式而不填充（PaddingMode.None）非常重要。此类设置配置使加密数据大小等于解密数据大小。

不幸的是，Mono（Mono Compiler for MVS2010 IDE v2.0.8152）编译代码会在数据加密时引发异常，并带有消息：

[Unhandled Exception: System.Security.Cryptography.CryptographicException: invalid block length at Mono.Security.Cryptography.SymmetricTransform.FinalEncrypt].

我使用本机Visual Studio 2010编译器在Windows XP和Windows 7下使用.NET framework 4.0进行了测试。我发现本机Microsoft .NET编译器不会抛出任何异常，并且代码示例运行良好。

下面我贴了两个例子（Repro代码），一个用于Mono，它抛出一个异常，一个用于本机C＃编译器，在这种情况下没有例外。此外，我还粘贴了在线编译器的链接来测试代码。

为什么Mono Compiler会抛出此异常？

单声道代码示例（用于测试的在线编译器，Compile Online）

using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;

namespace Dela.Mono.Examples
{
   public class HelloWorld
   {
      public static void Main(string[] args)
      {
         string plainText = "This will be encrypted.";
            string plainText2 = "";

            RijndaelManaged aesAlg = new RijndaelManaged();

            aesAlg.BlockSize = 128;
            aesAlg.KeySize = 256;
            aesAlg.Mode = CipherMode.CFB;
            aesAlg.FeedbackSize = 8;
            aesAlg.Padding = PaddingMode.None;

            aesAlg.GenerateKey();
            aesAlg.GenerateIV();

            ICryptoTransform encryptor = aesAlg.CreateEncryptor();

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

            Console.WriteLine(msEncrypt.ToArray().Length); 
            Console.WriteLine(System.Text.Encoding.UTF8.GetString(msEncrypt.ToArray()));

            byte[] customArray = msEncrypt.ToArray();

            ICryptoTransform decryptor = aesAlg.CreateDecryptor();

            MemoryStream msDecrypt = new MemoryStream(customArray);
            using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)) {
                using (StreamReader swDecrypt = new StreamReader(csDecrypt)) {
                    plainText2 = swDecrypt.ReadToEnd();
                }
            }

            Console.WriteLine(plainText2.Length); 
            Console.WriteLine(plainText2);


      }
   } 
}

Native C＃代码示例（用于测试的在线编译器，Compile Online）

// Rextester.Program.Main is the entry point for your code. Don't change it.

using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            string plainText = "This will be encrypted.";
            string plainText2 = "";

            RijndaelManaged aesAlg = new RijndaelManaged();

            aesAlg.BlockSize = 128;
            aesAlg.KeySize = 256;
            aesAlg.Mode = CipherMode.CFB;
            aesAlg.FeedbackSize = 8;
            aesAlg.Padding = PaddingMode.None;

            aesAlg.GenerateKey();
            aesAlg.GenerateIV();

            ICryptoTransform encryptor = aesAlg.CreateEncryptor();

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

            Console.WriteLine(msEncrypt.ToArray().Length); 
            Console.WriteLine(System.Text.Encoding.UTF8.GetString(msEncrypt.ToArray()));

            byte[] customArray = msEncrypt.ToArray();

            ICryptoTransform decryptor = aesAlg.CreateDecryptor();

            MemoryStream msDecrypt = new MemoryStream(customArray);
            using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)) {
                using (StreamReader swDecrypt = new StreamReader(csDecrypt)) {
                    plainText2 = swDecrypt.ReadToEnd();
                }
            }

            Console.WriteLine(plainText2.Length); 
            Console.WriteLine(plainText2);
        }
    }
}

Answer 1

错误已修复。源可以从单GIT存储库中获取。

master：e094d3dc0cf186f1de32d5340d847dc18aeca0e2

mono-2-10：98e4842eb19dfd60000ada19e9bfb265fad7c84b

使用CFB-8模式的Mono.Security.Cryptography RijndaelManaged类问题

1 个答案: