includes/password/UserPasswordPolicy.php

   1 <?php
   2 /**
   3  * Password policy checking for a user
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Check if a user's password complies with any password policies that apply to that
  25  * user, based on the user's group membership.
  26  * @since 1.26
  27  */
  28 class UserPasswordPolicy {
  29
  30         /**
  31          * @var array
  32          */
  33         private $policies;
  34
  35         /**
  36          * Mapping of statements to the function that will test the password for compliance. The
  37          * checking functions take the policy value, the user, and password, and return a Status
  38          * object indicating compliance.
  39          * @var array
  40          */
  41         private $policyCheckFunctions;
  42
  43         /**
  44          * @param array $policies
  45          * @param array $checks mapping statement to its checking function. Checking functions are
  46          * called with the policy value for this user, the user object, and the password to check.
  47          */
  48         public function __construct( array $policies, array $checks ) {
  49                 if ( !isset( $policies['default'] ) ) {
  50                         throw new InvalidArgumentException(
  51                                 'Must include a \'default\' password policy'
  52                         );
  53                 }
  54                 $this->policies = $policies;
  55
  56                 foreach ( $checks as $statement => $check ) {
  57                         if ( !is_callable( $check ) ) {
  58                                 throw new InvalidArgumentException(
  59                                         'Policy check functions must be callable'
  60                                 );
  61                         }
  62                         $this->policyCheckFunctions[$statement] = $check;
  63                 }
  64         }
  65
  66         /**
  67          * Check if a passwords meets the effective password policy for a User.
  68          * @param User $user who's policy we are checking
  69          * @param string $password the password to check
  70          * @return Status error to indicate the password didn't meet the policy, or fatal to
  71          *      indicate the user shouldn't be allowed to login.
  72          */
  73         public function checkUserPassword( User $user, $password ) {
  74                 $effectivePolicy = $this->getPoliciesForUser( $user );
  75                 $status = Status::newGood();
  76
  77                 foreach ( $effectivePolicy as $policy => $value ) {
  78                         if ( !isset( $this->policyCheckFunctions[$policy] ) ) {
  79                                 throw new DomainException( 'Invalid password policy config' );
  80                         }
  81                         $status->merge(
  82                                 call_user_func(
  83                                         $this->policyCheckFunctions[$policy],
  84                                         $value,
  85                                         $user,
  86                                         $password
  87                                 )
  88                         );
  89                 }
  90
  91                 return $status;
  92         }
  93
  94         /**
  95          * Get the policy for a user, based on their group membership. Public so
  96          * UI elements can access and inform the user.
  97          * @param User $user
  98          * @return array the effective policy for $user
  99          */
 100         public function getPoliciesForUser( User $user ) {
 101                 $effectivePolicy = self::getPoliciesForGroups(
 102                         $this->policies,
 103                         $user->getEffectiveGroups(),
 104                         $this->policies['default']
 105                 );
 106
 107                 Hooks::run( 'PasswordPoliciesForUser', array( $user, &$effectivePolicy ) );
 108
 109                 return $effectivePolicy;
 110         }
 111
 112         /**
 113          * Utility function to get the effective policy from a list of policies, based
 114          * on a list of groups.
 115          * @param array $policies list of policies to consider
 116          * @param array $userGroups the groups from which we calculate the effective policy
 117          * @param array $defaultPolicy the default policy to start from
 118          * @return array effective policy
 119          */
 120         public static function getPoliciesForGroups( array $policies, array $userGroups,
 121                 array $defaultPolicy
 122         ) {
 123                 $effectivePolicy = $defaultPolicy;
 124                 foreach ( $policies as $group => $policy ) {
 125                         if ( in_array( $group, $userGroups ) ) {
 126                                 $effectivePolicy = self::maxOfPolicies(
 127                                         $effectivePolicy,
 128                                         $policies[$group]
 129                                 );
 130                         }
 131                 }
 132
 133                 return $effectivePolicy;
 134         }
 135
 136         /**
 137          * Utility function to get a policy that is the most restrictive of $p1 and $p2. For
 138          * simplicity, we setup the policy values so the maximum value is always more restrictive.
 139          * @param array $p1
 140          * @param array $p2
 141          * @return array containing the more restrictive values of $p1 and $p2
 142          */
 143         public static function maxOfPolicies( array $p1, array $p2 ) {
 144                 $ret = array();
 145                 $keys = array_merge( array_keys( $p1 ), array_keys( $p2 ) );
 146                 foreach ( $keys as $key ) {
 147                         if ( !isset( $p1[$key] ) ) {
 148                                 $ret[$key] = $p2[$key];
 149                         } elseif ( !isset( $p2[$key] ) ) {
 150                                 $ret[$key] = $p1[$key];
 151                         } else {
 152                                 $ret[$key] = max( $p1[$key], $p2[$key] );
 153                         }
 154                 }
 155                 return $ret;
 156         }
 157
 158 }