直接粘程式碼，該類是基於微信公眾號訊息加密解密所提供的PHP DEMO改造而來，目前使用於彬彬大學APP介面token校驗中。

php的mcrypt 擴充套件已經過時了大約10年，並且用起來很複雜。因此它被廢棄並且被 OpenSSL 所取代。 從PHP 7.2起它將被從核心程式碼中移除並且移到PECL中。PHP手冊在7.1遷移頁面給出了替代方案,就是用OpenSSL取代MCrypt.

class Aes {

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

    private $key = '397e2eb61307109f6e68006ebcb62f98'; #Same as in JAVA

    function __construct($key) {
        $this->key = $key;
        $this->key = hash('sha256', $this->key, true);
    }

    /*
    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);

    }*/

    public function encrypt($input)
    {
        $data = openssl_encrypt($input, 'AES-256-CBC', $this->key, OPENSSL_RAW_DATA, $this->hexToStr($this->hex_iv));
        $data = base64_encode($data);
        return $data;
    }

    public function decrypt($input)
    {
        $decrypted = openssl_decrypt(base64_decode($input), 'AES-256-CBC', $this->key, OPENSSL_RAW_DATA, $this->hexToStr($this->hex_iv));
        return $decrypted;
    }

    /*

      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;
    }

}