AES 256解密错误

Question

我试图解密一个AES256位，但它给了我这个错误“解密数据的长度是无效的。”在线Plain_Text = Stream_Read.ReadToEnd();。我的加密方法有效，但解密不能。有人能帮助我吗？谢谢。

private static string Decrypt(string stringCypher_Text, string stringKey, string stringIV) 
    { 
     //Hashes, and converts key to bytes 
     //hash 
     //convert 
     System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding(); 
     Byte[] Key = encoding.GetBytes(stringKey); 

     //converts string IV to bytes 
     Byte[] IV = encoding.GetBytes(stringIV); 

     //converts cypher string to bytes 
     Byte[] Cypher_Text = encoding.GetBytes(stringCypher_Text); 

     RijndaelManaged Crypto = null; 
     MemoryStream MemStream = null; 
     ICryptoTransform Decryptor = null; 
     CryptoStream Crypto_Stream = null; 
     StreamReader Stream_Read = null; 
     string Plain_Text; 

     try 
     { 
      Crypto = new RijndaelManaged(); 
      Crypto.Key = Key; 
      Crypto.IV = IV; 

      MemStream = new MemoryStream(Cypher_Text); 

      //Create Decryptor make sure if you are decrypting that this is here and you did not copy paste encryptor. 
      Decryptor = Crypto.CreateDecryptor(Crypto.Key, Crypto.IV); 

      //This is different from the encryption look at the mode make sure you are reading from the stream. 
      Crypto_Stream = new CryptoStream(MemStream, Decryptor, CryptoStreamMode.Read); 

      //I used the stream reader here because the ReadToEnd method is easy and because it return a string, also easy. 
      Stream_Read = new StreamReader(Crypto_Stream); 
      Plain_Text = Stream_Read.ReadToEnd(); 

     } 
     finally 
     { 
      if (Crypto != null) 
       Crypto.Clear(); 

      MemStream.Flush(); 
      MemStream.Close(); 

     } 
     return Plain_Text; 

    } 

Answer 1

的问题是在你的加密方法或更准确的加密和解密之间的相互作用。 你真的不想对二进制数据使用UTF8Encoding或ANY编码。文本编码用于将文本转换为二进制数据并再次返回。加密文本实际上是纯粹的二进制数据。我会建议使用Base64Strings。

在你的Encrypt方法中，你很可能有一个MemoryStream，你正在返回编码字符。相反，返回这样的Base64String ...

string cipherText = Convert.ToBase64String(memoryStream.ToArray()); 
return cipherText; 

然后在你解密你采取的密文，并把它放回一个byte []像这样...

Byte[] Cypher_Text = Convert.FromBase64String(stringCypher_Text); 

你也应该通过你的关键和初始化向量作为Base64Strings以及之后，你的代码应该很好去。

Answer 2

尝试改变Plain_Text = Steam_Read.ReadToEnd();到

byte[] plainText = new byte[Plain_Text.Length]; 
    int dByte = Stream_Read.Read(plainText, 0, plainText.Length); 
    string decryptedText = Encoding.UTF8.GetString(plainText, 0, dByte); 
    return descryptedText;