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( $check ) ) {
  58                                 throw new InvalidArgumentException(
  59                                         "Policy check functions must be callable. '$statement' isn't 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          * @param string $purpose one of 'login', 'create', 'reset'
  71          * @return Status error to indicate the password didn't meet the policy, or fatal to
  72          *      indicate the user shouldn't be allowed to login.
  73          */
  74         public function checkUserPassword( User $user, $password, $purpose = 'login' ) {
  75                 $effectivePolicy = $this->getPoliciesForUser( $user, $purpose );
  76                 return $this->checkPolicies(
  77                         $user,
  78                         $password,
  79                         $effectivePolicy,
  80                         $this->policyCheckFunctions
  81                 );
  82         }
  83
  84         /**
  85          * Check if a passwords meets the effective password policy for a User, using a set
  86          * of groups they may or may not belong to. This function does not use the DB, so can
  87          * be used in the installer.
  88          * @param User $user who's policy we are checking
  89          * @param string $password the password to check
  90          * @param array $groups list of groups to which we assume the user belongs
  91          * @return Status error to indicate the password didn't meet the policy, or fatal to
  92          *      indicate the user shouldn't be allowed to login.
  93          */
  94         public function checkUserPasswordForGroups( User $user, $password, array $groups ) {
  95                 $effectivePolicy = self::getPoliciesForGroups(
  96                         $this->policies,
  97                         $groups,
  98                         $this->policies['default']
  99                 );
 100                 return $this->checkPolicies(
 101                         $user,
 102                         $password,
 103                         $effectivePolicy,
 104                         $this->policyCheckFunctions
 105                 );
 106         }
 107
 108         /**
 109          * @param User $user
 110          * @param string $password
 111          * @param array $policies
 112          * @param array $policyCheckFunctions
 113          * @return Status
 114          */
 115         private function checkPolicies( User $user, $password, $policies, $policyCheckFunctions ) {
 116                 $status = Status::newGood();
 117                 foreach ( $policies as $policy => $value ) {
 118                         if ( !isset( $policyCheckFunctions[$policy] ) ) {
 119                                 throw new DomainException( "Invalid password policy config. No check defined for '$policy'." );
 120                         }
 121                         $status->merge(
 122                                 call_user_func(
 123                                         $policyCheckFunctions[$policy],
 124                                         $value,
 125                                         $user,
 126                                         $password
 127                                 )
 128                         );
 129                 }
 130                 return $status;
 131         }
 132
 133         /**
 134          * Get the policy for a user, based on their group membership. Public so
 135          * UI elements can access and inform the user.
 136          * @param User $user
 137          * @param string $purpose one of 'login', 'create', 'reset'
 138          * @return array the effective policy for $user
 139          */
 140         public function getPoliciesForUser( User $user, $purpose = 'login' ) {
 141                 $effectivePolicy = $this->policies['default'];
 142                 if ( $purpose !== 'create' ) {
 143                         $effectivePolicy = self::getPoliciesForGroups(
 144                                 $this->policies,
 145                                 $user->getEffectiveGroups(),
 146                                 $this->policies['default']
 147                         );
 148                 }
 149
 150                 Hooks::run( 'PasswordPoliciesForUser', [ $user, &$effectivePolicy, $purpose ] );
 151
 152                 return $effectivePolicy;
 153         }
 154
 155         /**
 156          * Utility function to get the effective policy from a list of policies, based
 157          * on a list of groups.
 158          * @param array $policies list of policies to consider
 159          * @param array $userGroups the groups from which we calculate the effective policy
 160          * @param array $defaultPolicy the default policy to start from
 161          * @return array effective policy
 162          */
 163         public static function getPoliciesForGroups( array $policies, array $userGroups,
 164                 array $defaultPolicy
 165         ) {
 166                 $effectivePolicy = $defaultPolicy;
 167                 foreach ( $policies as $group => $policy ) {
 168                         if ( in_array( $group, $userGroups ) ) {
 169                                 $effectivePolicy = self::maxOfPolicies(
 170                                         $effectivePolicy,
 171                                         $policies[$group]
 172                                 );
 173                         }
 174                 }
 175
 176                 return $effectivePolicy;
 177         }
 178
 179         /**
 180          * Utility function to get a policy that is the most restrictive of $p1 and $p2. For
 181          * simplicity, we setup the policy values so the maximum value is always more restrictive.
 182          * @param array $p1
 183          * @param array $p2
 184          * @return array containing the more restrictive values of $p1 and $p2
 185          */
 186         public static function maxOfPolicies( array $p1, array $p2 ) {
 187                 $ret = [];
 188                 $keys = array_merge( array_keys( $p1 ), array_keys( $p2 ) );
 189                 foreach ( $keys as $key ) {
 190                         if ( !isset( $p1[$key] ) ) {
 191                                 $ret[$key] = $p2[$key];
 192                         } elseif ( !isset( $p2[$key] ) ) {
 193                                 $ret[$key] = $p1[$key];
 194                         } else {
 195                                 $ret[$key] = max( $p1[$key], $p2[$key] );
 196                         }
 197                 }
 198                 return $ret;
 199         }
 200
 201 }