本文实例讲述了PHP的AES加密算法。分享给大家供大家参考，具体如下：

<?php

class MCrypt {

  private $hex_iv = '00000000000000000000000000000000'; # converted JAVA byte code in to HEX and placed it here

  private $key = 'U1MjU1M0FDOUZ.Qz'; #Same as in JAVA

  function __construct() {

    $this->key = hash('sha256', $this->key, true);

    //echo $this->key.'<br/>';

  }

  function encrypt($str) {

    $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');

    mcrypt_generic_init($td, $this->key, $this->hexToStr($this->hex_iv));

    $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);

    $pad = $block - (strlen($str) % $block);

    $str .= str_repeat(chr($pad), $pad);

    $encrypted = mcrypt_generic($td, $str);

    mcrypt_generic_deinit($td);

    mcrypt_module_close($td);

    return base64_encode($encrypted);

  }

  function decrypt($code) {

    $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');

    mcrypt_generic_init($td, $this->key, $this->hexToStr($this->hex_iv));

    $str = mdecrypt_generic($td, base64_decode($code));

    $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);

    mcrypt_generic_deinit($td);

    mcrypt_module_close($td);

    return $this->strippadding($str);

  }

  /*

   For PKCS7 padding

   */

  private function addpadding($string, $blocksize = 16) {

    $len = strlen($string);

    $pad = $blocksize - ($len % $blocksize);

    $string .= str_repeat(chr($pad), $pad);

    return $string;

  }

  private function strippadding($string) {

    $slast = ord(substr($string, -1));

    $slastc = chr($slast);

    $pcheck = substr($string, -$slast);

    if (preg_match("/$slastc{" . $slast . "}/", $string)) {

      $string = substr($string, 0, strlen($string) - $slast);

      return $string;

    } else {

      return false;

    }

  }

  function hexToStr($hex)

  {

    $string='';

    for ($i=0; $i < strlen($hex)-1; $i+=2)

    {

      $string .= chr(hexdec($hex[$i].$hex[$i+1]));

    }

    return $string;

  }

}

$encryption = new MCrypt();

echo $encryption->encrypt('123456') . "<br/>";

echo $encryption->decrypt('tpyxISJ83dqEs3uw8bN/+w==');

?>

希望本文所述对大家PHP程序设计有所帮助。