WP：AesManaged加密與mcrypt_encrypt

Question

我想在C＃和PHP之間同步我的加密和解密方法，但似乎出了問題。

在Windows Phone 7 SDK，可以用AESManaged對數據進行加密

我用下面的方法：

public static string EncryptA(string dataToEncrypt, string password, string salt) 
    { 
     AesManaged aes = null; 
     MemoryStream memoryStream = null; 
     CryptoStream cryptoStream = null; 

     try 
     { 
      //Generate a Key based on a Password, Salt and HMACSHA1 pseudo-random number generator 
      Rfc2898DeriveBytes rfc2898 = new Rfc2898DeriveBytes(password, Encoding.UTF8.GetBytes(salt)); 

      //Create AES algorithm with 256 bit key and 128-bit block size 
      aes = new AesManaged(); 
      aes.Key = rfc2898.GetBytes(aes.KeySize/8); 
      aes.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; // rfc2898.GetBytes(aes.BlockSize/8); 

      // to check my results against those of PHP 
      var blaat1 = Convert.ToBase64String(aes.Key); 
      var blaat2 = Convert.ToBase64String(aes.IV); 

      //Create Memory and Crypto Streams 
      memoryStream = new MemoryStream(); 
      cryptoStream = new CryptoStream(memoryStream, aes.CreateEncryptor(), CryptoStreamMode.Write); 

      //Encrypt Data 
      byte[] data = Encoding.Unicode.GetBytes(dataToEncrypt); 
      cryptoStream.Write(data, 0, data.Length); 
      cryptoStream.FlushFinalBlock(); 

      //Return Base 64 String 
      string result = Convert.ToBase64String(memoryStream.ToArray()); 

      return result; 
     } 
     finally 
     { 
      if (cryptoStream != null) 
       cryptoStream.Close(); 

      if (memoryStream != null) 
       memoryStream.Close(); 

      if (aes != null) 
       aes.Clear(); 
     } 
    } 

我解決產生的關鍵問題。 Key和IV與PHP端的類似。但隨後加密的最後一步出錯了。

這裏是我的PHP代碼

<?php 

function pbkdf2($p, $s, $c, $dk_len, $algo = 'sha1') { 

    // experimentally determine h_len for the algorithm in question 
    static $lengths; 
    if (!isset($lengths[$algo])) { $lengths[$algo] = strlen(hash($algo, null, true)); } 
    $h_len = $lengths[$algo]; 

    if ($dk_len > (pow(2, 32) - 1) * $h_len) { 
     return false; // derived key is too long 
    } else { 
     $l = ceil($dk_len/$h_len); // number of derived key blocks to compute 
     $t = null; 
     for ($i = 1; $i <= $l; $i++) { 
      $f = $u = hash_hmac($algo, $s . pack('N', $i), $p, true); // first iterate 
      for ($j = 1; $j < $c; $j++) { 
       $f ^= ($u = hash_hmac($algo, $u, $p, true)); // xor each iterate 
      } 
      $t .= $f; // concatenate blocks of the derived key 
     } 
     return substr($t, 0, $dk_len); // return the derived key of correct length 
    } 

} 


$password = 'test'; 
$salt = 'saltsalt'; 
$text = "texttoencrypt"; 

#$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC); 
#echo $iv_size . '<br/>'; 
#$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); 
#print_r (mcrypt_list_algorithms()); 

$iv = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"; 

$key = pbkdf2($password, $salt, 1000, 32); 
echo 'key: ' . base64_encode($key) . '<br/>'; 
echo 'iv: ' . base64_encode($iv) . '<br/>'; 

echo '<br/><br/>'; 

function addpadding($string, $blocksize = 32){ 
    $len = strlen($string); 
    $pad = $blocksize - ($len % $blocksize); 
    $string .= str_repeat(chr($pad), $pad); 
    return $string; 
} 

echo 'text: ' . $text . '<br/>'; 
echo 'text: ' . addpadding($text) . '<br/>'; 

// -- works till here 

$crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $text, MCRYPT_MODE_CBC, $iv); 

echo '1.' . $crypttext . '<br/>'; 
$crypttext = base64_encode($crypttext); 
echo '2.' . $crypttext . '<br/>'; 

$crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, addpadding($text), MCRYPT_MODE_CBC, $iv); 

echo '1.' . $crypttext . '<br/>'; 
$crypttext = base64_encode($crypttext); 
echo '2.' . $crypttext . '<br/>'; 

?> 

因此指出，密鑰和IV看在.NET和PHP類似的事，但似乎執行mcrypt_encrypt時是想錯在最後調用（） 。最終的結果，加密的字符串與.NET不同。

有人可以告訴我我做錯了什麼。據我所知，一切都應該是正確的。

謝謝！

編輯：在.NET的AESManaged對象上

附加信息

密鑰大小= 256 模式= CBC 填充= PKCS7

Answer 1

我解決了這個問題。你需要確保你的字符串使用utf8編碼，並且使用正確的填充（PKCS7）

下面是代碼：

public static string EncryptA(string dataToEncrypt, string password, string salt) 
    { 
     AesManaged aes = null; 
     MemoryStream memoryStream = null; 
     CryptoStream cryptoStream = null; 

     try 
     { 
      //Generate a Key based on a Password, Salt and HMACSHA1 pseudo-random number generator 
      Rfc2898DeriveBytes rfc2898 = new Rfc2898DeriveBytes(password, Encoding.UTF8.GetBytes(salt)); 

      //Create AES algorithm with 256 bit key and 128-bit block size 
      aes = new AesManaged(); 
      aes.Key = rfc2898.GetBytes(aes.KeySize/8); 
      aes.IV = Encoding.UTF8.GetBytes("AAAAAAAAAAAAAAAA"); // new byte[] { 0x41, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; // rfc2898.GetBytes(aes.BlockSize/8); 

      //Create Memory and Crypto Streams 
      memoryStream = new MemoryStream(); 
      cryptoStream = new CryptoStream(memoryStream, aes.CreateEncryptor(aes.Key, aes.IV), CryptoStreamMode.Write); 

      //Encrypt Data 
      byte[] data = Encoding.UTF8.GetBytes(dataToEncrypt); 
      cryptoStream.Write(data, 0, data.Length); 
      cryptoStream.FlushFinalBlock(); 

      //Return Base 64 String 
      var temp = memoryStream.ToArray(); 
      string result = Convert.ToBase64String(temp); 

      return result; 
     } 
     finally 
     { 
      if (cryptoStream != null) 
       cryptoStream.Close(); 

      if (memoryStream != null) 
       memoryStream.Close(); 

      if (aes != null) 
       aes.Clear(); 
     } 
    } 

，並在PHP中：

<?php 
function pbkdf2($p, $s, $c, $dk_len, $algo = 'sha1') { 

    // experimentally determine h_len for the algorithm in question 
    static $lengths; 
    if (!isset($lengths[$algo])) { $lengths[$algo] = strlen(hash($algo, null, true)); } 
    $h_len = $lengths[$algo]; 

    if ($dk_len > (pow(2, 32) - 1) * $h_len) { 
     return false; // derived key is too long 
    } else { 
     $l = ceil($dk_len/$h_len); // number of derived key blocks to compute 
     $t = null; 
     for ($i = 1; $i <= $l; $i++) { 
      $f = $u = hash_hmac($algo, $s . pack('N', $i), $p, true); // first iterate 
      for ($j = 1; $j < $c; $j++) { 
       $f ^= ($u = hash_hmac($algo, $u, $p, true)); // xor each iterate 
      } 
      $t .= $f; // concatenate blocks of the derived key 
     } 
     return substr($t, 0, $dk_len); // return the derived key of correct length 
    } 
} 

$text = "blaat"; 
$password = 'this is my secret passwordthis is my secret password'; 
$salt = 'thisismysalt'; 

#$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC); 
#$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); 

$iv = 'AAAAAAAAAAAAAAAA'; 

$key = pbkdf2($password, $salt, 1000, 32); 
echo 'key size: ' . strlen($key) . '<br/>'; 
echo 'key: ' . base64_encode($key) . '<br/>'; 
echo 'iv size: ' . strlen($iv) . '<br/>'; 
#echo 'iv: ' . $iv . '<br/>'; 
echo 'iv: ' . base64_encode($iv) . '<br/>'; 

echo '<br/><br/>'; 

# $data = $this->paddingAlgorithm->padData($data, $blockSize); 
# return $iv . mcrypt_encrypt($this->MCRYPT_DES, $keyBytes, $data, MCRYPT_MODE_CBC, $iv); 

function addpadding($string) 
{ 
    $blocksize = 16; 
    $len = strlen($string); 
    $pad = $blocksize - ($len % $blocksize); 
    $string .= str_repeat(chr($pad), $pad); 

    return $string; 
} 

$crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, addpadding($text), MCRYPT_MODE_CBC, $iv); 
$crypttext = base64_encode($crypttext); 
echo '3. [' . $crypttext . ']<br/>'; 

echo '<br/>'; 

?> 

希望這也會幫助某人。

Paulo謝謝你的幫助！

Answer 2

MCRYPT_RIJNDAEL_256是與塊大小256的版本的Rijndael算法的位，而AES只是塊大小爲128位的版本。這些不兼容。

使用MCRYPT_RIJNDAEL_128，得到相當於AES的算法。它仍支持標準化爲AES的所有三種密鑰尺寸，即128位（16字節），196位（24字節）和256位（32字節）。只需傳遞足夠長的字符串作爲鍵。