hotpalgorithm.php

<?php
 
namespace Bitrix\Main\Security\Mfa;
 
use Bitrix\Main\Config\Option;
use Bitrix\Main\ArgumentOutOfRangeException;
use Bitrix\Main\Security\OtpException;
use Bitrix\Main\Localization\Loc;
 
Loc::loadMessages(__FILE__);
 
class HotpAlgorithm extends OtpAlgorithm
{
    const SYNC_WINDOW = 15000;
    protected static $type = 'hotp';
    protected $window = 10;
 
    public function __construct()
    {
        $window = (int)Option::get('security', 'hotp_user_window', 10);
        if ($window && $window > 0)
        {
            $this->window = $window;
        }
    }
 
    public function verify($input, $params = null)
    {
        $input = (string)$input;
 
        if (!preg_match('#^\d+$#D', $input))
        {
            throw new ArgumentOutOfRangeException('input', 'string with numbers');
        }
 
        $counter = (int)$params;
        $result = false;
        $window = $this->window;
        while ($window--)
        {
            if ($this->isStringsEqual($input, $this->generateOTP($counter)))
            {
                $result = true;
                break;
            }
            $counter++;
        }
 
        if ($result === true)
        {
            return [true, $counter + 1];
        }
 
        return [false, null];
    }
 
    public function generateUri($label, array $opts = [])
    {
        $opts += ['counter' => 1];
        return parent::generateUri($label, $opts);
    }
 
    public function getSyncParameters($inputA, $inputB)
    {
        $counter = 0;
        $this->window = 1;
        for ($i = 0; $i < self::SYNC_WINDOW; $i++)
        {
            [$verifyA,] = $this->verify($inputA, $counter);
            [$verifyB,] = $this->verify($inputB, $counter + 1);
            $counter++;
            if ($verifyA && $verifyB)
            {
                break;
            }
        }
 
        if ($i === self::SYNC_WINDOW)
        {
            throw new OtpException('Cannot synchronize this secret key with the provided password values.');
        }
 
        return $counter;
    }
}