* @copyright 2015 Jim Wigginton * @license http://www.opensource.org/licenses/mit-license.html MIT License * @link http://phpseclib.sourceforge.net */ namespace phpseclib\Crypt\ECDSA; use phpseclib\Crypt\ECDSA; use phpseclib\Crypt\Hash; use phpseclib\Math\BigInteger; use phpseclib\Crypt\ECDSA\Signature\ASN1 as ASN1Signature; use phpseclib\Crypt\ECDSA\BaseCurves\TwistedEdwards as TwistedEdwardsCurve; use phpseclib\Crypt\ECDSA\Curves\Ed25519; use phpseclib\Crypt\ECDSA\Keys\PKCS1; use phpseclib\Crypt\ECDSA\Keys\PKCS8; use phpseclib\Crypt\Common; /** * ECDSA Public Key * * @package ECDSA * @author Jim Wigginton * @access public */ class PublicKey extends ECDSA implements Common\PublicKey { use Common\Fingerprint; /** * Verify a signature * * @see self::verify() * @access public * @param string $message * @param string $signature * @return mixed */ public function verify($message, $signature) { $order = $this->curve->getOrder(); if ($this->curve instanceof TwistedEdwardsCurve) { if ($this->curve instanceof Ed25519 && self::$engines['libsodium'] && !isset($this->context)) { return sodium_crypto_sign_verify_detached($signature, $message, $this->toString('libsodium')); } $curve = $this->curve; if (strlen($signature) != 2 * $curve::SIZE) { return false; } $R = substr($signature, 0, $curve::SIZE); $S = substr($signature, $curve::SIZE); try { $R = PKCS1::extractPoint($R, $curve); $R = $this->curve->convertToInternal($R); } catch (\Exception $e) { return false; } $S = strrev($S); $S = new BigInteger($S, 256); if ($S->compare($order) >= 0) { return false; } $A = $curve->encodePoint($this->QA); if ($curve instanceof Ed25519) { $dom2 = !isset($this->context) ? '' : 'SigEd25519 no Ed25519 collisions' . "\0" . chr(strlen($this->context)) . $this->context; } else { $context = isset($this->context) ? $this->context : ''; $dom2 = 'SigEd448' . "\0" . chr(strlen($context)) . $context; } $hash = new Hash($curve::HASH); $k = $hash->hash($dom2 . substr($signature, 0, $curve::SIZE) . $A . $message); $k = strrev($k); $k = new BigInteger($k, 256); list(, $k) = $k->divide($order); $qa = $curve->convertToInternal($this->QA); $lhs = $curve->multiplyPoint($curve->getBasePoint(), $curve->convertInteger($S)); $rhs = $curve->multiplyPoint($qa, $curve->convertInteger($k)); $rhs = $curve->addPoint($rhs, $R); $rhs = $curve->convertToAffine($rhs); return $lhs[0]->equals($rhs[0]) && $lhs[1]->equals($rhs[1]); } $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', ['namedCurve' => false]), $this->hash->getHash()); if ($result != -1) { return (bool) $result; } } $n_1 = $order->subtract(self::$one); if (!$r->between(self::$one, $n_1) || !$s->between(self::$one, $n_1)) { return false; } $e = $this->hash->hash($message); $e = new BigInteger($e, 256); $Ln = $this->hash->getLength() - $order->getLength(); $z = $Ln > 0 ? $e->bitwise_rightShift($Ln) : $e; $w = $s->modInverse($order); list(, $u1) = $z->multiply($w)->divide($order); list(, $u2) = $r->multiply($w)->divide($order); $u1 = $this->curve->convertInteger($u1); $u2 = $this->curve->convertInteger($u2); list($x1, $y1) = $this->curve->multiplyAddPoints( [$this->curve->getBasePoint(), $this->QA], [$u1, $u2] ); $x1 = $x1->toBigInteger(); list(, $x1) = $x1->divide($order); return $x1->equals($r); } /** * Returns the public key * * @param string $type * @param array $options optional * @return string */ public function toString($type, array $options = []) { $type = self::validatePlugin('Keys', $type, 'savePublicKey'); return $type::savePublicKey($this->curve, $this->QA, $options); } }