PKCS7 AES-256-CBC

<?php
$key = '11345678901234561234567890123456';
$iv  = '1234567890123456';
$method  = "AES-256-CBC";
$options = OPENSSL_RAW_DATA;
$text        = "Really";
$pkc_encoder = new PKCS7Encoder();
$text        = $pkc_encoder->encode($text);
$res  = openssl_encrypt($text, $method, $key, $options, $iv);
echo "pkcs7: " . bin2hex($text);
echo "\n";
echo "encrypted: " . bin2hex($res);


class PKCS7Encoder
{
    public static $block_size = 32;
    public function encode($text)
    {
        $block_size  = self::$block_size;
        $text_length = strlen($text);
        //计算需要填充的位数
        $amount_to_pad = self::$block_size - ($text_length % self::$block_size);
        if ($amount_to_pad == 0) {
            $amount_to_pad = self::block_size;
        }
        //获得补位所用的字符
        $pad_chr = chr($amount_to_pad);
        $tmp     = '';
        for ($index = 0; $index < $amount_to_pad; $index++) {
            $tmp .= $pad_chr;
        }
        return $text . $tmp;
    }
}