C# AES解密c

我试图解密字节，但在read=cryptoStream.Readbuffer，0，len行中有一个错误，要解密的数据长度无效；inputFile.lenght=4256，len=4256

这是解密的代码

        byte[] salt = new byte[32];

        FileStream fsCrypt = new FileStream(inputFile, FileMode.Open);

        fsCrypt.Seek(fsCrypt.Length - 376, SeekOrigin.Begin);
        fsCrypt.Read(salt, 0, salt.Length);
        byte[] passwordBytes = Encoding.UTF8.GetBytes(password);
        RijndaelManaged AES = new RijndaelManaged();
        AES.KeySize = 256;
        AES.BlockSize = 128;
        var key = new Rfc2898DeriveBytes(passwordBytes, salt, 50000);
        AES.Key = key.GetBytes(AES.KeySize / 8);
        AES.IV = key.GetBytes(AES.BlockSize / 8);
        AES.Padding = PaddingMode.PKCS7;
        AES.Mode = CipherMode.CFB;
        int read;
        byte[] buffer = new byte[1048576];
        List < byte > bytes = new List < byte > ();

        fsCrypt.Seek(0, SeekOrigin.Begin);
        read = 1;
        var len = Convert.ToInt32(fsCrypt.Length);

        MemoryStream mem = new MemoryStream();
        fsCrypt.CopyTo(mem);
        mem.Position = 0;
        using(CryptoStream cryptoStream = new CryptoStream(mem, AES.CreateDecryptor(), CryptoStreamMode.Read)) // CryptoStream cryptoStream = new CryptoStream(fsCrypt, AES.CreateDecryptor(), CryptoStreamMode.Read
         {
          //var buffer2 = new byte[len];
          while ((read = cs.Read(buffer, 0, buffer.Length)) > 0) {
           foreach(var m in buffer)
           bytes.Add(m);
          }
         }

您可以调用encrypted=msEncrypt.ToArray；加密太早，它必须在csEncrypt的using语句结束之后，以便将所有数据刷新到内存流中

同样，在解密过程中，您也开始在文件的早期进行解密

fsCrypt.SeekfsCrypt.Length-376，SeekOrigin.Begin；应该是fsCrypt.SeekfsCrypt.Length-32，SeekOrigin.Begin；如果你写出来的盐长度是32

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最后，在将salt数据传递给mem之前，您也没有修剪salt，因此您将salt数据与cyphertext一起传递到流中，这会使您的消息过长。

您解密的数据长度为wrong@JoePhillips我添加了我如何编码文件的代码，你能检查一下吗；使用CryptoStream csEncrypt=new CryptoStreammsEncrypt，AES.CreateEncryptor，CryptoStreamMode.Write后，再次解密时我会出错非常感谢，不要告诉我如何从流中切盐？ty，我写了这个fsCrypt.SetLengthfsCrypt.Length-32；解码没有错误和正确，但我在文本后有这么多空间，在记事本++中显示NULL哦，我想我理解是的，NULL我修复了，但现在添加到结尾OЩ-ЖЖЖЖФ»r'іъ

byte[] salt = GenerateRandomSalt();


 //convert password string to byte arrray
 byte[] passwordBytes = System.Text.Encoding.UTF8.GetBytes(password);

 //Set Rijndael symmetric encryption algorithm 71 246
 RijndaelManaged AES = new RijndaelManaged();
 AES.KeySize = 256;
 AES.BlockSize = 128;
 AES.Padding = PaddingMode.PKCS7;


 var key = new Rfc2898DeriveBytes(passwordBytes, salt, 50000);
 AES.Key = key.GetBytes(AES.KeySize / 8);
 AES.IV = key.GetBytes(AES.BlockSize / 8);

 AES.Mode = CipherMode.CFB;
 var kk = key.ToString();


 FileStream fsIn = new FileStream(inputFile, FileMode.Open);


 byte[] buffer = new byte[1048576];
 int read = 0;



 byte[] encrypted;
 using(MemoryStream msEncrypt = new MemoryStream()) {
  using(CryptoStream csEncrypt = new CryptoStream(msEncrypt, AES.CreateEncryptor(), CryptoStreamMode.Write)) {
   fsIn.Seek(0, SeekOrigin.Begin);

   while ((read = fsIn.Read(buffer, 0, buffer.Length)) > 0) {
    csEncrypt.Write(buffer, 0, read);
   }
   encrypted = msEncrypt.ToArray();
  }
 }

 fsIn.Seek(0, SeekOrigin.Begin);
 fsIn.Write(encrypted, 0, encrypted.Length);

 fsIn.Seek(fsIn.Length, SeekOrigin.Begin);
 fsIn.Write(salt, 0, salt.Length);