我写信是为了报告密码学问题。使用. RijndaelManaged_ System.Security.Cryptography对我来说，使用RijndaelManaged( CFB-8FeedbackSize = 8) 模式而不使用填充 ( PaddingMode.None) 很重要。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) 编译的代码在数据加密时抛出异常并显示消息：
[Unhandled Exception: System.Security.Cryptography.CryptographicException: invalid block length at Mono.Security.Cryptography.SymmetricTransform.FinalEncrypt].
我使用原生 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。
下面我粘贴了两个示例（复制代码），一个用于引发异常的 Mono，另一个用于本机 C# 编译器，在这种情况下没有异常。此外，我还粘贴了在线编译器的链接来测试代码。
为什么 Mono 编译器会抛出此异常？
Mono 代码示例（用于测试的在线编译器，在线编译）
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);
}
}
}
本机 C# 代码示例（用于测试的在线编译器，在线编译）
// 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);
}
}
}