<?php
/**
* DSA Private Key
*
* @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 phpseclib3\Crypt\DSA;
use phpseclib3\Crypt\Common;
use phpseclib3\Crypt\DSA;
use phpseclib3\Crypt\DSA\Formats\Signature\ASN1 as ASN1Signature;
use phpseclib3\Math\BigInteger;
/**
* DSA Private Key
*
* @author Jim Wigginton <terrafrost@php.net>
*/
final class PrivateKey extends DSA implements Common\PrivateKey
{
use Common\Traits\PasswordProtected;
/**
* DSA secret exponent x
*
* @var \phpseclib3\Math\BigInteger
*/
protected $x;
/**
* Returns the public key
*
* If you do "openssl rsa -in private.rsa -pubout -outform PEM" you get a PKCS8 formatted key
* that contains a publicKeyAlgorithm AlgorithmIdentifier and a publicKey BIT STRING.
* An AlgorithmIdentifier contains an OID and a parameters field. With RSA public keys this
* parameters field is NULL. With DSA PKCS8 public keys it is not - it contains the p, q and g
* variables. The publicKey BIT STRING contains, simply, the y variable. This can be verified
* by getting a DSA PKCS8 public key:
*
* "openssl dsa -in private.dsa -pubout -outform PEM"
*
* ie. just swap out rsa with dsa in the rsa command above.
*
* A PKCS1 public key corresponds to the publicKey portion of the PKCS8 key. In the case of RSA
* the publicKey portion /is/ the key. In the case of DSA it is not. You cannot verify a signature
* without the parameters and the PKCS1 DSA public key format does not include the parameters.
*
* @see self::getPrivateKey()
* @return mixed
*/
public function getPublicKey()
{
$type = self::validatePlugin('Keys', 'PKCS8', 'savePublicKey');
if (!isset($this->y)) {
$this->y = $this->g->powMod($this->x, $this->p);
}
$key = $type::savePublicKey($this->p, $this->q, $this->g, $this->y);
return DSA::loadFormat('PKCS8', $key)
->withHash($this->hash->getHash())
->withSignatureFormat($this->shortFormat);
}
/**
* Create a signature
*
* @see self::verify()
* @param string $message
* @return mixed
*/
public function sign($message)
{
$format = $this->sigFormat;
if (self::$engines['OpenSSL'] && in_array($this->hash->getHash(), openssl_get_md_methods())) {
$signature = '';
$result = openssl_sign($message, $signature, $this->toString('PKCS8'), $this->hash->getHash());
if ($result) {
if ($this->shortFormat == 'ASN1') {
return $signature;
}
extract(ASN1Signature::load($signature));
return $format::save($r, $s);
}
}
$h = $this->hash->hash($message);
$h = $this->bits2int($h);
while (true) {
$k = BigInteger::randomRange(self::$one, $this->q->subtract(self::$one));
$r = $this->g->powMod($k, $this->p);
list(, $r) = $r->divide($this->q);
if ($r->equals(self::$zero)) {
continue;
}
$kinv = $k->modInverse($this->q);
$temp = $h->add($this->x->multiply($r));
$temp = $kinv->multiply($temp);
list(, $s) = $temp->divide($this->q);
if (!$s->equals(self::$zero)) {
break;
}
}
// the following is an RFC6979 compliant implementation of deterministic DSA
// it's unused because it's mainly intended for use when a good CSPRNG isn't
// available. if phpseclib's CSPRNG isn't good then even key generation is
// suspect
/*
$h1 = $this->hash->hash($message);
$k = $this->computek($h1);
$r = $this->g->powMod($k, $this->p);
list(, $r) = $r->divide($this->q);
$kinv = $k->modInverse($this->q);
$h1 = $this->bits2int($h1);
$temp = $h1->add($this->x->multiply($r));
$temp = $kinv->multiply($temp);
list(, $s) = $temp->divide($this->q);
*/
return $format::save($r, $s);
}
/**
* Returns the private key
*
* @param string $type
* @param array $options optional
* @return string
*/
public function toString($type, array $options = [])
{
$type = self::validatePlugin('Keys', $type, 'savePrivateKey');
if (!isset($this->y)) {
$this->y = $this->g->powMod($this->x, $this->p);
}
return $type::savePrivateKey($this->p, $this->q, $this->g, $this->y, $this->x, $this->password, $options);
}
}
In the digital age, privacy concerns have become increasingly paramount, prompting the European Union to enact the General Data Protection Regulation (GDPR) in 2018. Among its many provisions, GDPR sets strict guidelines for the collection and processing of personal data, including the use of cookies on websites. Privacy Policy
