PHP完整的AES加解密算法使用及例子（256位）

<?php

class aes {
 

// CRYPTO_CIPHER_BLOCK_SIZE 32
    
private secret_key = 'default_secret_key';
public function setKey($key) {
  $this->_secret_key = $key;
}
public function encode($data) {
  $td = mcrypt_module_open(MCRYPT_RIJNDAEL_256,'',MCRYPT_MODE_CBC,'');
  $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td),MCRYPT_RAND);
  mcrypt_generic_init($td,$this->_secret_key,$iv);
  $encrypted = mcrypt_generic($td,$data);
  mcrypt_generic_deinit($td);
  return $iv . $encrypted;
}
public function decode($data) {
  $td = mcrypt_module_open(MCRYPT_RIJNDAEL_256,'',MCRYPT_MODE_CBC,'');
  $iv = mb_substr($data,0,32,'latin1');
  mcrypt_generic_init($td,$this->_secret_key,$iv);
  $data = mb_substr($data,32,mb_strlen($data,'latin1'),'latin1');
  $data = mdecrypt_generic($td,$data);
  mcrypt_generic_deinit($td);
  mcrypt_module_close($td);
  return trim($data);
}
}
$aes = new aes();
$aes->setKey('key');
// 加密
$string = $aes->encode('string');
// 解密
$aes->decode($string);
?>