[PHP知识库]php加解密

public function bbbAction()
    {
        $str='cab';
        echo "加密前：".$str;
        $str=self::passport_encrypt($str);
        echo "加密后：".$str;
        $str=self::passport_decrypt($str);
        echo "解密后：".$str;
        $str='ccc1asddddddddddddddddddddddddddddddddddddddddddddd';
        echo "加密前：".$str;
        $str=self::passport_encrypt($str);
        echo "加密后：".$str;
        $str=self::passport_decrypt($str);
        echo "解密后：".$str;
    }
    //--------------------------------------------------------------------------
    /*
     * 对字符串进行解密处理
     * @param string 需要解密的密文
     */
    public static function passport_decrypt($str)
    {
        $str = self::passport_key(base64_decode($str), \toprank\server\getConst::getConst('MD5KEY'));
        $tmp = "";

        if ((strlen($str) % 2) != 0) {
            return $str;
        }

        for ($i = 0; $i < strlen($str); $i++) {
            $md5 = $str[$i];
            $tmp .= $str[++$i] ^ $md5;
        }

        return $tmp;
    }
    //--------------------------------------------------------------------------
    /*
     * 对字符串进行加密处理
     * @param string 需要加密的内容
     */
    public static function passport_encrypt($str)
    {
        srand((double) microtime() * 1122345);
        $encrypt_key = md5(rand(0, 32000));
        $ctr         = 0;
        $tmp         = "";

        for ($i = 0; $i < strlen($str); $i++) {
            $ctr = ($ctr == strlen($encrypt_key) ? 0 : $ctr);
            $tmp .= $encrypt_key[$ctr] . ($str[$i] ^ $encrypt_key[$ctr++]);
        }

        return base64_encode(self::passport_key($tmp, \toprank\server\getConst::getConst('MD5KEY')));
    }

    /*
     * 辅助函数
     */
    public static function passport_key($str, $encrypt_key)
    {
        $encrypt_key = md5($encrypt_key);
        $ctr         = 0;
        $tmp         = "";

        for ($i = 0; $i < strlen($str); $i++) {
            $ctr = ($ctr == strlen($encrypt_key) ? 0 : $ctr);
            $tmp .= $str[$i] ^ $encrypt_key[$ctr++];
        }

        return $tmp;
    }