includes/password/Argon2Password.php

   1 <?php
   2
   3 use Wikimedia\Assert\Assert;
   4
   5 /**
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  */
  23
  24 /**
  25  * Implements Argon2, a modern key derivation algorithm designed to resist GPU cracking and
  26  * side-channel attacks.
  27  *
  28  * @see https://en.wikipedia.org/wiki/Argon2
  29  */
  30 class Argon2Password extends Password {
  31         /**
  32          * @var null[] Array with known password_hash() option names as keys
  33          */
  34         private static $knownOptions = [
  35                 'memory_cost' => null,
  36                 'time_cost' => null,
  37                 'threads' => null,
  38         ];
  39
  40         /**
  41          * @inheritDoc
  42          */
  43         protected function isSupported() {
  44                 // It is actually possible to have a PHP build with Argon2i but not Argon2id
  45                 return defined( 'PASSWORD_ARGON2I' ) || defined( 'PASSWORD_ARGON2ID' );
  46         }
  47
  48         /**
  49          * @return mixed[] Array of 2nd and third parmeters to password_hash()
  50          */
  51         private function prepareParams() {
  52                 switch ( $this->config['algo'] ) {
  53                         case 'argon2i':
  54                                 $algo = PASSWORD_ARGON2I;
  55                                 break;
  56                         case 'argon2id':
  57                                 $algo = PASSWORD_ARGON2ID;
  58                                 break;
  59                         case 'auto':
  60                                 $algo = defined( 'PASSWORD_ARGON2ID' ) ? PASSWORD_ARGON2ID : PASSWORD_ARGON2I;
  61                                 break;
  62                         default:
  63                                 throw new LogicException( "Unexpected algo: {$this->config['algo']}" );
  64
  65                 }
  66
  67                 $params = array_intersect_key( $this->config, self::$knownOptions );
  68
  69                 return [ $algo, $params ];
  70         }
  71
  72         /**
  73          * @inheritDoc
  74          */
  75         public function crypt( $password ) {
  76                 list( $algo, $params ) = $this->prepareParams();
  77                 $this->hash = password_hash( $password, $algo, $params );
  78         }
  79
  80         /**
  81          * @inheritDoc
  82          */
  83         public function equals( $other ) {
  84                 if ( is_string( $other ) ) {
  85                         return $this->verify( $other );
  86                 }
  87
  88                 // Argon2 key derivation is not deterministic, can't pass objects to equals()
  89                 return false;
  90         }
  91
  92         /**
  93          * @inheritDoc
  94          */
  95         public function verify( $password ) {
  96                 Assert::parameterType( 'string', $password, '$password' );
  97
  98                 return password_verify( $password, $this->hash );
  99         }
 100
 101         /**
 102          * @inheritDoc
 103          */
 104         public function toString() {
 105                 $res = ":argon2:{$this->hash}";
 106                 $this->assertIsSafeSize( $res );
 107                 return $res;
 108         }
 109
 110         /**
 111          * @inheritDoc
 112          */
 113         public function needsUpdate() {
 114                 list( $algo, $params ) = $this->prepareParams();
 115                 return password_needs_rehash( $this->hash, $algo, $params );
 116         }
 117 }