(前言：我是一个具有加密和安全性的新手,认为这是一种有趣的学习方式)

我正在用C#构建一个程序,该程序与使用标准HTTP协议用PHP编写的服务器通信.我希望两个程序都能够发送和接收加密的数据.但是,尽管加密和加密都使用相同的功能,但在处理方式上似乎存在不一致之处.

这两个程序在CBC模式下都使用Rjindael 128位.

为了演示/测试,我制作了两个几乎相同的函数,每个函数采用相同的字符串,对其进行加密,然后将结果作为base64字符串吐出.

PHP函数：

public static function EncryptionTest () {
  echo 'Testing Encryption to base64 string...<br/>';

  $originalString = 'This is the original String! How cool is that?';

  $key = "abcdefghijklmnopqrstuvwxyz012345";
  $iv = "1234567890123456";

  $encrypted = mcrypt_encrypt (MCRYPT_RIJNDAEL_128, $key, $originalString, MCRYPT_MODE_CBC, $iv);

  echo base64_encode ($encrypted);
}

与C#对应：

public static void EncryptionTest ()
{
  System.Console.WriteLine ("Testing Encryption to base64 string...");

  string originalString = "This is the original String! How cool is that?";
  byte [] encryptedData;
  byte [] key = System.Text.ASCIIEncoding.UTF8.GetBytes ("abcdefghijklmnopqrstuvwxyz012345");
  byte [] iv = System.Text.ASCIIEncoding.UTF8.GetBytes ("1234567890123456");

  RijndaelManaged cryptor = new RijndaelManaged ();
  cryptor.Key = key;
  cryptor.IV = iv;
  cryptor.BlockSize = 128;
  cryptor.Mode = CipherMode.CBC;

  ICryptoTransform encryptor = cryptor.CreateEncryptor (cryptor.Key, cryptor.IV);

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

  System.Console.WriteLine (System.Convert.ToBase64String (encryptedData) );
}

现在,这是PHP结果：

Testing Encryption to base64 string…
yzwIdowhLj+cMOFPMuHSA80pWQ6R8yfFQlEsLx5kIzUOJdFykLjsaKfK4VfaBGRv

和C#结果：

Testing Encryption to base64 string…
yzwIdowhLj+cMOFPMuHSA80pWQ6R8yfFQlEsLx5kIzUg74mGEQf9iW+OQ68m6cpp

如您所见,这两个结果都经过明确加密(好),字符数相同(好),但不同(可能不好).

我编写了解密测试,接受这些字符串并对其进行处理.这是PHP函数：

public static function DecryptionTest () {
  $phpBase64 = 'yzwIdowhLj+cMOFPMuHSA80pWQ6R8yfFQlEsLx5kIzUOJdFykLjsaKfK4VfaBGRv';
  $csBase64 =  'yzwIdowhLj+cMOFPMuHSA80pWQ6R8yfFQlEsLx5kIzUg74mGEQf9iW+OQ68m6cpp';

  $key = "abcdefghijklmnopqrstuvwxyz012345";
  $iv = "1234567890123456";

  $phpEncrypted = base64_decode ($phpBase64);
  $phpDecrypted = mcrypt_decrypt (MCRYPT_RIJNDAEL_128, $key, $phpEncrypted, MCRYPT_MODE_CBC, $iv);

  $csEncrypted = base64_decode ($csBase64);
  $csDecrypted = mcrypt_decrypt (MCRYPT_RIJNDAEL_128, $key, $csEncrypted, MCRYPT_MODE_CBC, $iv);

  echo 'Decrypted PHP string: "' . $phpDecrypted . '"<br/>' .
       'Decrypted CS string:  "' . $csDecrypted . '"';
}

和C#版本：

public static void DecryptionTest ()
{
  System.Console.WriteLine ("Testing Decryption for PHP and CS generated base64 strings!");

  string phpBase64 = "yzwIdowhLj+cMOFPMuHSA80pWQ6R8yfFQlEsLx5kIzUOJdFykLjsaKfK4VfaBGRv";
  string csBase64 = "yzwIdowhLj+cMOFPMuHSA80pWQ6R8yfFQlEsLx5kIzUg74mGEQf9iW+OQ68m6cpp";

  byte [] phpEncrypted = System.Convert.FromBase64String (phpBase64);
  byte [] csEncrypted = System.Convert.FromBase64String (csBase64);

  string phpDecrypted;
  string csDecrypted;

  byte [] encryptedData;
  byte [] key = System.Text.ASCIIEncoding.UTF8.GetBytes ("abcdefghijklmnopqrstuvwxyz012345");
  byte [] iv = System.Text.ASCIIEncoding.UTF8.GetBytes ("1234567890123456");

  RijndaelManaged cryptor = new RijndaelManaged ();
  cryptor.Key = key;
  cryptor.IV = iv;
  cryptor.BlockSize = 128;
  cryptor.Mode = CipherMode.CBC;

  ICryptoTransform decryptor = cryptor.CreateDecryptor (cryptor.Key, cryptor.IV);

  using (MemoryStream msDecrypt = new MemoryStream (csEncrypted))
  {
    using (CryptoStream csDecrypt = new CryptoStream (msDecrypt, decryptor, CryptoStreamMode.Read))
    {
      using (StreamReader swDecrypt = new StreamReader (csDecrypt) )
      {
        csDecrypted = swDecrypt.ReadToEnd ();
      }
    }
  }
  System.Console.WriteLine ("Decrypted CS string: \"" + csDecrypted + "\"");

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

  System.Console.WriteLine ("Decrypted PHP string: \"" + phpDecrypted + "\"");      
}

PHP结果：

Decrypted PHP string: “This is the original String! How cool is that?”

Decrypted CS string: “This is the original String! How cool is that?”

和C#结果：

Decrypted CS string: “This is the original String! How cool is that?”

CryptographicException: Bad PKCS7 padding. Invalid length 0.
at Mono.Security.Cryptography.SymmetricTransform.ThrowBadPaddingException (PaddingMode padding, Int32 length, Int32 position) [0x0005c] in > /Applications/buildAgent/work/84669f285f6a667f/mcs/class/corlib/Mono.Security.Cryptography/SymmetricTransform.cs:363

因此,基本上,PHP代码可以成功解密两个base64字符串,但是C#代码只能解密由其自己的解密程序创建的base64字符串.

其中很多是我在互联网上找到的代码,可以根据自己的需要进行修改.就像我说的那样,我是密码学的新手,但是我在这里已经很不错了.我可以整天进行理论化和测试,但是它开始陷入我的日程安排中,因此我正在寻找其他人对其不起作用的见解.谢谢！

解决方法:

您需要使用PHPSecLib,因为PHP实现与C/C++#不兼容.它具有不同的填充大小(这里不是加密专家,但这是我经过几天的测试发现的).因此,使用phpseclib中的本机实现即可.

我本人在不久前就遇到了这个问题.但是使用C/C++ryptoAPI和PHP.