<?php

/**
 * OpenSSL Modular Exponentiation Engine
 *
 * PHP version 5 and 7
 *
 * @author    Jim Wigginton <terrafrost@php.net>
 * @copyright 2017 Jim Wigginton
 * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
 * @link      http://pear.php.net/package/Math_BigInteger
 */

namespace phpseclib3\Math\BigInteger\Engines;

use phpseclib3\Crypt\RSA\Formats\Keys\PKCS8;
use phpseclib3\Math\BigInteger;

/**
 * OpenSSL Modular Exponentiation Engine
 *
 * @author  Jim Wigginton <terrafrost@php.net>
 */
abstract class OpenSSL
{
    /**
     * Test for engine validity
     *
     * @return bool
     */
    public static function isValidEngine()
    {
        return extension_loaded('openssl') && static::class != __CLASS__;
    }

    /**
     * Performs modular exponentiation.
     *
     * @param Engine $x
     * @param Engine $e
     * @param Engine $n
     * @return Engine
     */
    public static function powModHelper(Engine $x, Engine $e, Engine $n)
    {
        if ($n->getLengthInBytes() < 31 || $n->getLengthInBytes() > 16384) {
            throw new \OutOfRangeException('Only modulo between 31 and 16384 bits are accepted');
        }

        $key = PKCS8::savePublicKey(
            new BigInteger($n),
            new BigInteger($e)
        );

        $plaintext = str_pad($x->toBytes(), $n->getLengthInBytes(), "\0", STR_PAD_LEFT);

        // this is easily prone to failure. if the modulo is a multiple of 2 or 3 or whatever it
        // won't work and you'll get a "failure: error:0906D06C:PEM routines:PEM_read_bio:no start line"
        // error. i suppose, for even numbers, we could do what PHP\Montgomery.php does, but then what
        // about odd numbers divisible by 3, by 5, etc?
        if (!openssl_public_encrypt($plaintext, $result, $key, OPENSSL_NO_PADDING)) {
            throw new \UnexpectedValueException(openssl_error_string());
        }

        $class = get_class($x);
        return new $class($result, 256);
    }
}

• [D] BCMath
• [D] GMP
• [D] PHP
• [F] BCMath.php
  Delete
• [F] Engine.php
  Delete
• [F] GMP.php
  Delete
• [F] OpenSSL.php
  Delete
• [F] PHP.php
  Delete
• [F] PHP32.php
  Delete
• [F] PHP64.php
  Delete

How To Payment

Simple Steps to Complete Your Payment Securely and Efficiently

Making a payment on our website is quick and secure. Start by logging in or creating an account. Select your preferred payment method, input the required details, and review the information. Once you confirm everything is correct, click on the "Submit Payment" button. You’ll receive instant confirmation and can track your payment status through your account dashboard. It’s an easy and secure process.

• Go to the Payment Section: Access the payment area on our website or app.
• Choose Your Payment Method: Select your preferred payment option.
• Enter Payment Details: Provide the necessary payment information.
• Verify Your Information: Check that all details are correct.
• Confirm Your Payment: Click "Submit Payment" to complete the transaction.