PHP类封装AES加解密

<?php
/**
 * 功能:Aes字符串加解密
 */

class AES
{
    protected $key;
    protected $method;
    protected $iv;
    protected $options;
    public function __construct($method = 'AES-128-ECB', $iv = '', $options = OPENSSL_RAW_DATA )
    {
        $this->key = substr(md5("123456"),0,16);
        #密钥参数
        $this->method = $method;
        $this->iv = $iv;
        $this->options = $options;
    }

    /**
     *
     * @param string $string 需要加密的字符串
     * @return string
     */
    public function encrypt( $string )
    {
        // $key = substr(openssl_digest(openssl_digest($string, 'sha1', true), 'sha1', true), 0, 16);
        // $data = openssl_encrypt($string, 'AES-128-ECB', $key, OPENSSL_RAW_DATA);
        // return urlencode(base64_encode($data));
        // if (strlen($string) % 16) {
        //     $string = str_pad($string,strlen($string) + 16 - strlen($string) % 16, "\0");
        // }
        // $encrypted =  openssl_encrypt($string, 'AES-128-ECB',$this->key,OPENSSL_ZERO_PADDING,$this->iv);
        // return base64_encode($encrypted);
        return base64_encode(openssl_encrypt($string, $this->method,$this->key,$this->options,$this->iv));
    }

    /**
     * @param string $string 需要解密的字符串
     * @param string $key 密钥
     * @return string
     */
    public function decrypt($string)
    {
        return openssl_decrypt(base64_decode($string), $this->method, $this->key, $this->options,$this->iv);
    }
}