php

<?php

class AesCrypt
{
    //初始化向量
    private $iv = '84195bd96a8a2e7f';

    //Mcrypt算法
    private $cipher = MCRYPT_RIJNDAEL_128;

    //Mcrypt支持的加密模型  特别适用于对文件进行加密。 相比 ECB， 它的安全性有明显提升。
    private $mode = MCRYPT_MODE_CBC;

    public function encrypt($str, $key = '')
    {
        $str = $this->addPKCS7Padding($str);

        $encrypted = mcrypt_encrypt($this->cipher, $key, $str, $this->mode, $this->iv);

        return $encrypted;
    }

    public function decrypt($code, $key = '')
    {
        $decrypted = mcrypt_decrypt($this->cipher, $key, $code, $this->mode, $this->iv);

        $decrypted = $this->stripPKSC7Padding($decrypted);

        return $decrypted;
    }

    protected function addPKCS7Padding($source)
    {
        $block = mcrypt_get_block_size($this->cipher, $this->mode);

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

        $char = chr($pad);

        $source .= str_repeat($char, $pad);

        return $source;
    }

    public function stripPKSC7Padding($source)
    {
        $char = substr($source, -1);
        $num = ord($char);
        $source = substr($source, 0, -$num);
        return $source;
    }
}