Question

我正在学习C＃，正在练习解密和加密。

但是，当我尝试解密文本文件时，没有任何反应。

我认为我在解密功能中做错了，所以我用字符串测试了。

解密与字符串完美配合所以我想知道我做错了什么。

这是我的加密和解密的样子：

  //The encryption
  string path = @"C:\encrypt.txt"; 
  //The path where my .txt file is.
  string textfile = File.ReadAllText(path); 
  //Reading the text in the file and storing it in a string.
  byte[] ByteToEncrypt = EncryptStringToBytes(textfile, myAes.Key, myAes.IV); 
  //From The Aes class example
  string encrypted = ""; 
  //Creating a string to store the bytes in.
   for (int i = 0; i < ByteToEncrypt.Length; i++)
   {
   encrypted = encrypted + ByteToEncrypt[i]; 
   //Adding all the bytes from an array to string.
   }
   File.WriteAllText(path, encrypted, LATIN1); 
  //Writing the encrypted string to the .txtfile.

  //The decryption
   string decrypted = DecryptStringFromBytes(ByteToEncrypt, myAes.Key, myAes.IV); 
  //From the Aes class example.
   File.WriteAllText(path, Decrypted, LATIN1); 
 //Writing the decrypted string to textfile.

我在下面发布Aes课程以获取更多信息。

 static byte[] EncryptStringToBytes(string plaintext, byte[] Key, byte[] IV)
    {
        //Checking the arguments
        if (string.IsNullOrEmpty(plaintext))
        {
            throw new ArgumentNullException("plaintext");
        }
        else if (Key == null || Key.Length <= 0)
        {
            throw new ArgumentNullException("key");
        }
        else if (IV == null || IV.Length <= 0)
        {
            throw new ArgumentNullException("IV");
        }
        byte[] encrypted;
        //Create an Aes object
        //With the specified key and IV
        using (Aes Aesalg = Aes.Create())
        {
            Aesalg.Key = Key;
            Aesalg.IV = IV;
            //Create a encryptor to perform the stream transform
            ICryptoTransform encryptor = Aesalg.CreateEncryptor(Aesalg.Key, Aesalg.IV);
            //Create the streams used for encryption
            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)
    {
        if (ciphertext == null || ciphertext.Length <= 0)
        {
            throw new ArgumentNullException("plaintext");
        }
        else if (Key == null || Key.Length <= 0)
        {
            throw new ArgumentNullException("Key");
        }
        else if (IV == null || IV.Length <= 0)
        {
            throw new ArgumentNullException("IV");
        }
        string plaintext = null;

        using (Aes Aesalg = Aes.Create())
        {
            Aesalg.Key = Key;
            Aesalg.IV = IV;
            ICryptoTransform decryptor = Aesalg.CreateDecryptor(Aesalg.Key, Aesalg.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;
    }

Answer 1

您不能只为字符串添加字节。字节可以包含00和FF之间的任何值（使用十六进制表示）。您似乎只是将这些字节作为整数添加到字符串中，如

encrypted = encrypted + ByteToEncrypt[i];

只为字节值"0255"和00创建一个字符串值，例如FF。当然，当你尝试解密这样一个字符串时，你会遇到一个问题，只是因为字节不再分开了。

相反，您应该在加密后创建密文的base 64编码，并在解密之前将其转换回字节。或者，正如ntoskrnl建议的那样，你当然可以将密文一直视为二进制文件，如果这是一个选项。

解密与Aes无法在文本文件中工作

1 个答案: