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tgseclib/phpseclib/Crypt/DSA/PublicKey.php

92 lines
2.4 KiB
PHP

<?php
/**
* DSA Public Key
*
* @category Crypt
* @package DSA
* @author Jim Wigginton <terrafrost@php.net>
* @copyright 2015 Jim Wigginton
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @link http://phpseclib.sourceforge.net
*/
namespace phpseclib\Crypt\DSA;
use phpseclib\Crypt\DSA;
use phpseclib\Crypt\ECDSA\Signature\ASN1 as ASN1Signature;
use phpseclib\Crypt\Common;
/**
* DSA Public Key
*
* @package DSA
* @author Jim Wigginton <terrafrost@php.net>
* @access public
*/
class PublicKey extends DSA implements Common\PublicKey
{
use Common\Fingerprint;
/**
* Verify a signature
*
* @see self::verify()
* @access public
* @param string $message
* @param string $signature
* @param string $format optional
* @return mixed
*/
public function verify($message, $signature)
{
$format = $this->format;
$params = $format::load($signature);
if ($params === false || count($params) != 2) {
return false;
}
extract($params);
if (self::$engines['OpenSSL'] && in_array($this->hash->getHash(), openssl_get_md_methods())) {
$sig = $format != 'ASN1' ? ASN1Signature::save($r, $s) : $signature;
$result = openssl_verify($message, $sig, $this->toString('PKCS8'), $this->hash->getHash());
if ($result != -1) {
return (bool) $result;
}
}
$q_1 = $this->q->subtract(self::$one);
if (!$r->between(self::$one, $q_1) || !$s->between(self::$one, $q_1)) {
return false;
}
$w = $s->modInverse($this->q);
$h = $this->hash->hash($message);
$h = $this->bits2int($h);
list(, $u1) = $h->multiply($w)->divide($this->q);
list(, $u2) = $r->multiply($w)->divide($this->q);
$v1 = $this->g->powMod($u1, $this->p);
$v2 = $this->y->powMod($u2, $this->p);
list(, $v) = $v1->multiply($v2)->divide($this->p);
list(, $v) = $v->divide($this->q);
return $v->equals($r);
}
/**
* Returns the public key
*
* @param string $type
* @return string
*/
public function toString($type)
{
$type = self::validatePlugin('Keys', $type, 'savePublicKey');
return $type::savePublicKey($this->p, $this->q, $this->g, $this->y);
}
}