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