hmacalgorithm.php

<?php
namespace Bitrix\Main\Security\Sign;
 
use Bitrix\Main\ArgumentOutOfRangeException;
use Bitrix\Main\ArgumentTypeException;
 
class HmacAlgorithm
    extends SigningAlgorithm
{
    // ToDo: need option here?
    // Default hashing algorithm used by HMAC
    protected $hashAlgorithm = 'sha256';
 
 
    public function __construct($hashAlgorithm = null)
    {
        if ($hashAlgorithm)
            $this->setHashAlgorithm($hashAlgorithm);
    }
 
    public function setHashAlgorithm($hashAlgorithm)
    {
        if (!in_array($hashAlgorithm, hash_algos()))
            throw new ArgumentOutOfRangeException('hashAlgorithm', hash_algos());
 
        $this->hashAlgorithm = $hashAlgorithm;
        return $this;
    }
 
    public function getHashAlgorithm()
    {
        return $this->hashAlgorithm;
    }
 
    public function getSignature($value, $key)
    {
        return hash_hmac($this->hashAlgorithm, $value, $key, true);
    }
 
    public function verify($value, $key, $sig)
    {
        return $this->compareStrings(
            $this->getSignature($value, $key),
            $sig
        );
    }
 
    protected function compareStrings($expected, $actual)
    {
        if (!is_string($expected))
        {
            throw new ArgumentTypeException('expected', 'string');
        }
 
        if (!is_string($actual))
        {
            throw new ArgumentTypeException('actual', 'string');
        }
 
        $lenExpected = strlen($expected);
        $lenActual = strlen($actual);
 
        $status = $lenExpected ^ $lenActual;
        $len = min($lenExpected, $lenActual);
        for ($i = 0; $i < $len; $i++)
        {
            $status |= ord($expected[$i]) ^ ord($actual[$i]);
        }
 
        return $status === 0;
    }
 
}