C# 和 PHP MCrypt 之间的 AES 加密和解密

Question

我似乎在获取 AES256 字符串以在 PHP 和 .NET 应用程序之间进行解码时遇到问题。我在 .Net 应用程序中收到一条错误消息，指出“填充无效且无法删除”。此错误在 CrytoStream 的 using 语句中触发。工作流程非常简单。 PHP 应用程序加密一个值并将其作为 URL 参数传递给 .NET 应用程序。 .NET 应用程序需要解密该值以供以后使用。 .NET 方法适用于 .NET 到 .NET，但 PHP 到 .NET 是问题所在。

PHP 代码：

   function encrypt($text) {
    $key = "M2AZULUALPHA";
    $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
    $padding = $block - (strlen($text) % $block);
    $text .= str_repeat(chr($padding), $padding);

    $crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $text, MCRYPT_MODE_CBC, 'TripBuilder2017');
    return base64_encode($crypttext);
 }

.NET 解密方法：

    private string Decrypt(string cipherText)
    {
        string EncryptionKey = "M2AZULUALPHA";
        byte[] saltArray = Encoding.ASCII.GetBytes("TripBuilder2017");

        cipherText = cipherText.Replace(" ", "+");
        byte[] cipherBytes = Convert.FromBase64String(cipherText);
        using (Aes encryptor = Aes.Create())
        {
            Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, saltArray);
            encryptor.KeySize = 256;
            encryptor.Padding = PaddingMode.PKCS7;
            encryptor.Key = pdb.GetBytes(32);
            encryptor.IV = pdb.GetBytes(16);

            using (MemoryStream ms = new MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
                {
                    cs.Write(cipherBytes, 0, cipherBytes.Length);
                    cs.Close();
                }
                cipherText = Encoding.Unicode.GetString(ms.ToArray());
            }
        }
        return cipherText;
    }

更新 我将 PHP 中的模式更改为 Rijndael256，我还将 AES 更改为 .NET 中的 RijndaelManaged。同样，我可以在 .NET 应用程序之间使用它，但不能在 PHP 应用程序中使用。我想知道 PHP 应用程序使用的填充是否存在问题。

Answer 1

我在消息后完全更新了答案:-)

php:

function encrypt($text) 
    {

    //$key = "M2AZULUALPHA"; //  type 2 -- mcrypt_encrypt(): Key of size 12 not supported by this algorithm. Only keys of sizes 16, 24 or 32 supported -- at line 7
    $key = "M2AZULUALPHA1234";
    //$vi ='TripBuilder2017'; // type 2 -- mcrypt_encrypt(): Received initialization vector of size 15, but size 16 is required for this encryption mode -- at line 9
    $vi ='TripBuilder20170';
    $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
    $padding = $block - (strlen($text) % $block);
    $text .= str_repeat(chr($padding), $padding);
    $crypttext = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $text, MCRYPT_MODE_CBC, $vi));
    return $crypttext;
    }

    $result = encrypt("abcdcddsfdafdfe");
    echo"$result";

输出为“pPPH8amRhqbdX6D83jr74A=="

c# 与RijndaelManaged

public String Decrypt(string cipherText)
        {
            var result = "";
            var cypher = Convert.FromBase64String(cipherText);
            var encoding = System.Text.Encoding.UTF8;
            var Key = encoding.GetBytes("M2AZULUALPHA1234");
            var IV = encoding.GetBytes("TripBuilder20170"); 
            using (var rj = new RijndaelManaged())
            {
                rj.Padding = PaddingMode.PKCS7;
                rj.Mode = CipherMode.CBC;
                rj.KeySize = 256;
                rj.Key = Key;
                rj.IV = IV;
                var ms = new MemoryStream(cypher);
                using (var cs = new CryptoStream(ms, rj.CreateDecryptor(Key, IV), CryptoStreamMode.Read))
                using (var sr = new StreamReader(cs))
                    result = sr.ReadToEnd();
            }

            return result;
        }

测试：

var result = Decrypt("pPPH8amRhqbdX6D83jr74A==");
Debug.WriteLine(result);

输出是“abcdcddsfdafdfe”