无法使用使用PHP（Rijdael-128）加密的C#解密数据

我使用以下代码使用PHP解密数据：

$content="1234";
$cp = mcrypt_module_open('rijndael-128', '', 'cbc', '');
$iv = mcrypt_create_iv(16, MCRYPT_RAND);
$key = pack("H*",md5('a'));
mcrypt_generic_init($cp, $key, $iv);
$encrypted = mcrypt_generic($cp, $content);
echo base64_encode($key)."\n";
echo base64_encode($iv)."\n";
echo base64_encode($encrypted)."\n";
mcrypt_generic_deinit($cp);
mcrypt_module_close($cp);

$iv和$encrypted然后保存到文件中，并在C#示例应用程序中读取：

var iv=...;
var encrypted=...;
var md5 = new MD5CryptoServiceProvider();
var key = md5.ComputeHash(Encoding.Default.GetBytes("a"));
md5.Clear();

Console.WriteLine(Convert.ToBase64String(key));
Console.WriteLine(Convert.ToBase64String(iv));
Console.WriteLine(Convert.ToBase64String(encrypted));

这里的输出与PHP的输出完全相同，因此我可以保证两者之间没有编码错误

var rd = new RijndaelManaged {
  Key = key,
  IV = iv,
  Mode = CipherMode.CBC,
  KeySize = 128,
  Padding = PaddingMode.Zeros
};

var buffer = new byte[encrypted.Length];
using(var ms = new MemoryStream(buffer)) {
  using(var cs = new CryptoStream(ms, rd.CreateDecryptor(), CryptoStreamMode.Write)) {
    cs.Write(encrypted, 0, encrypted.Length);
    ms.Read(buffer, 0, buffer.Length);
    Console.WriteLine(Encoding.Default.GetString(buffer));
  } 
}
rd.Clear();

解密的结果在每次程序启动时都会发生变化，即使输入数据完全相同：

首次运行：

---

dmf1ucdxtqgxw5niaxmyq==好吧，修改我过去罪恶的一个旧样本，我最终得出以下结论：

static string Decrypt() {            
  byte[] keyBytes = Convert.FromBase64String("DMF1ucDxtqgxw5niaXcmYQ==");
  byte[] iv = Convert.FromBase64String("GoCeRkrL/EMKNH/BYeLsqQ==");
  byte[] cipherTextBytes = Convert.FromBase64String("UBE3DkgbJgj1K/TISugLxA==");

  var symmetricKey = new RijndaelManaged { Mode = CipherMode.CBC, IV = iv, KeySize = 128, Key = keyBytes, Padding = PaddingMode.Zeros};

  using (var decryptor = symmetricKey.CreateDecryptor())
  using (var ms = new MemoryStream(cipherTextBytes))
  using (var cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read)) {
    var plainTextBytes = new byte[cipherTextBytes.Length];
    int decryptedByteCount = cs.Read(plainTextBytes, 0, plainTextBytes.Length);
    return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
  }
}

---

其中给出了尾随\0个字符的“1234”。。您是不是又忘记将字节[]转换为字符串了？我还缺少什么不同之处？

解决方案非常简单，但大多数都很烦人。。。在设置“Key”属性之前，必须先设置“KeySize”属性。我一步一步地转换我的代码以匹配您的代码，当我切换两个setter时，它就工作了。如果有来自微软的人在听，您可以将这些信息包含到MSDN中。我知道，一旦你知道了，这是显而易见的，但是。。。本杰明，丹克！

static string Decrypt() {            
  byte[] keyBytes = Convert.FromBase64String("DMF1ucDxtqgxw5niaXcmYQ==");
  byte[] iv = Convert.FromBase64String("GoCeRkrL/EMKNH/BYeLsqQ==");
  byte[] cipherTextBytes = Convert.FromBase64String("UBE3DkgbJgj1K/TISugLxA==");

  var symmetricKey = new RijndaelManaged { Mode = CipherMode.CBC, IV = iv, KeySize = 128, Key = keyBytes, Padding = PaddingMode.Zeros};

  using (var decryptor = symmetricKey.CreateDecryptor())
  using (var ms = new MemoryStream(cipherTextBytes))
  using (var cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read)) {
    var plainTextBytes = new byte[cipherTextBytes.Length];
    int decryptedByteCount = cs.Read(plainTextBytes, 0, plainTextBytes.Length);
    return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
  }
}