Von PHP implementierte AES-Verschlüsselungsklasse

<?php
class AESMcrypt {

 public $iv = null;
 public $key = null;
 public $bit = 128;
 private $cipher;

 public function construct($bit, $key, $iv, $mode) {
  if(empty($bit) || empty($key) || empty($iv) || empty($mode))
  return NULL;

  $this->bit = $bit;
  $this->key = $key;
  $this->iv = $iv;
  $this->mode = $mode;

  switch($this->bit) {
   case 192:$this->cipher = MCRYPT_RIJNDAEL_192; break;
   case 256:$this->cipher = MCRYPT_RIJNDAEL_256; break;
   default: $this->cipher = MCRYPT_RIJNDAEL_128;
  }

  switch($this->mode) {
   case &#39;ecb&#39;:$this->mode = MCRYPT_MODE_ECB; break;
   case &#39;cfb&#39;:$this->mode = MCRYPT_MODE_CFB; break;
   case &#39;ofb&#39;:$this->mode = MCRYPT_MODE_OFB; break;
   case &#39;nofb&#39;:$this->mode = MCRYPT_MODE_NOFB; break;
   default: $this->mode = MCRYPT_MODE_CBC;
  }
 }

 public function encrypt($data) {
  $data = base64_encode(mcrypt_encrypt( $this->cipher, $this->key, $data, $this->mode, $this->iv));
  return $data;
 }

 public function decrypt($data) {
  $data = mcrypt_decrypt( $this->cipher, $this->key, base64_decode($data), $this->mode, $this->iv);
  $data = rtrim(rtrim($data), "\x00..\x1F");
  return $data;
 }

}
//使用方法
$aes = new AESMcrypt($bit = 128, $key = &#39;abcdef1234567890&#39;, $iv = &#39;0987654321fedcba&#39;, $mode = &#39;cbc&#39;);
$c = $aes->encrypt(&#39;haowei.me&#39;);
var_dump($aes->decrypt($c));