Jafar\Bundle\GuardedAuthenticationBundle\Api\JWTSigner\Signer\OpenSSL\HMAC

Complexity

Total Complexity

3

Size/Duplication

Total Lines	46
Duplicated Lines	0 %

Importance

Changes

0

3 Methods

Rating	Name	Duplication	Size	Complexity
A	verify()	0	5	1
A	sign()	0	3	1
A	timingSafeEquals()	0	3	1

<?php
/*
 * This file is part of the Guarded Authentication package.
 *
 * (c) Jafar Jabr <jafaronly@yahoo.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Jafar\Bundle\GuardedAuthenticationBundle\Api\JWTSigner\Signer\OpenSSL;

use Jafar\Bundle\GuardedAuthenticationBundle\Api\JWTSigner\Signer\SignerInterface;

/**
 * Class HMAC.
 * This class is the base of all HMAC Signers.
 *
 * @author Jafar Jabr <jafaronly@yahoo.com>
 */
abstract class HMAC implements SignerInterface
{
    /**
     * {@inheritdoc}
     */
    public function sign($input, $key)
    {
        return hash_hmac($this->getHashingAlgorithm(), $input, (string) $key, true);
    }

    /**
     * To prevent timing attacks we are using PHP 5.6 native function hash_equals,
     * in case of PHP < 5.6 a timing safe equals comparison function.
     *
     * more info here:
     *  http://blog.ircmaxell.com/2014/11/its-all-about-time.html
     *
     *
     * {@inheritdoc}
     */
    public function verify($key, $signature, $input)
    {
        $signedInput = $this->sign($input, $key);

        return $this->timingSafeEquals($signedInput, $signature);
    }

    /**
     * A timing safe equals comparison.
     *
     * @param string $known the internal signature to be checked
     * @param string $input The signed input submitted value
     *
     * @return bool true if the two strings are identical
     */
    public function timingSafeEquals($known, $input)
    {
        return hash_equals($known, $input);
    }

    /**
     * Returns the hashing algorithm used in this signer.
     *
     * @return string
     */
    abstract public function getHashingAlgorithm();
}