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. The status value will be an array,
  72          *   potentially with the following keys:
  73          *   - forceChange: do not allow the user to login without changing the password if invalid.
  74          */
  75         public function checkUserPassword( User $user, $password ) {
  76                 $effectivePolicy = $this->getPoliciesForUser( $user );
  77                 return $this->checkPolicies(
  78                         $user,
  79                         $password,
  80                         $effectivePolicy,
  81                         $this->policyCheckFunctions
  82                 );
  83         }
  84
  85         /**
  86          * Check if a passwords meets the effective password policy for a User, using a set
  87          * of groups they may or may not belong to. This function does not use the DB, so can
  88          * be used in the installer.
  89          * @param User $user who's policy we are checking
  90          * @param string $password the password to check
  91          * @param array $groups list of groups to which we assume the user belongs
  92          * @return Status error to indicate the password didn't meet the policy, or fatal to
  93          *   indicate the user shouldn't be allowed to login. The status value will be an array,
  94          *   potentially with the following keys:
  95          *   - forceChange: do not allow the user to login without changing the password if invalid.
  96          */
  97         public function checkUserPasswordForGroups( User $user, $password, array $groups ) {
  98                 $effectivePolicy = self::getPoliciesForGroups(
  99                         $this->policies,
 100                         $groups,
 101                         $this->policies['default']
 102                 );
 103                 return $this->checkPolicies(
 104                         $user,
 105                         $password,
 106                         $effectivePolicy,
 107                         $this->policyCheckFunctions
 108                 );
 109         }
 110
 111         /**
 112          * @param User $user
 113          * @param string $password
 114          * @param array $policies
 115          * @param array $policyCheckFunctions
 116          * @return Status
 117          */
 118         private function checkPolicies( User $user, $password, $policies, $policyCheckFunctions ) {
 119                 $status = Status::newGood( [] );
 120                 $forceChange = false;
 121                 foreach ( $policies as $policy => $settings ) {
 122                         if ( !isset( $policyCheckFunctions[$policy] ) ) {
 123                                 throw new DomainException( "Invalid password policy config. No check defined for '$policy'." );
 124                         }
 125                         if ( !is_array( $settings ) ) {
 126                                 // legacy format
 127                                 $settings = [ 'value' => $settings ];
 128                         }
 129                         if ( !array_key_exists( 'value', $settings ) ) {
 130                                 throw new DomainException( "Invalid password policy config. No value defined for '$policy'." );
 131                         }
 132                         $value = $settings['value'];
 133                         /** @var StatusValue $policyStatus */
 134                         $policyStatus = call_user_func(
 135                                 $policyCheckFunctions[$policy],
 136                                 $value,
 137                                 $user,
 138                                 $password
 139                         );
 140                         if ( !$policyStatus->isGood() && !empty( $settings['forceChange'] ) ) {
 141                                 $forceChange = true;
 142                         }
 143                         $status->merge( $policyStatus );
 144                 }
 145                 if ( $status->isOK() && $forceChange ) {
 146                         $status->value['forceChange'] = true;
 147                 }
 148                 return $status;
 149         }
 150
 151         /**
 152          * Get the policy for a user, based on their group membership. Public so
 153          * UI elements can access and inform the user.
 154          * @param User $user
 155          * @return array the effective policy for $user
 156          */
 157         public function getPoliciesForUser( User $user ) {
 158                 $effectivePolicy = self::getPoliciesForGroups(
 159                         $this->policies,
 160                         $user->getEffectiveGroups(),
 161                         $this->policies['default']
 162                 );
 163
 164                 Hooks::run( 'PasswordPoliciesForUser', [ $user, &$effectivePolicy ] );
 165
 166                 return $effectivePolicy;
 167         }
 168
 169         /**
 170          * Utility function to get the effective policy from a list of policies, based
 171          * on a list of groups.
 172          * @param array $policies list of policies to consider
 173          * @param array $userGroups the groups from which we calculate the effective policy
 174          * @param array $defaultPolicy the default policy to start from
 175          * @return array effective policy
 176          */
 177         public static function getPoliciesForGroups( array $policies, array $userGroups,
 178                 array $defaultPolicy
 179         ) {
 180                 $effectivePolicy = $defaultPolicy;
 181                 foreach ( $policies as $group => $policy ) {
 182                         if ( in_array( $group, $userGroups ) ) {
 183                                 $effectivePolicy = self::maxOfPolicies(
 184                                         $effectivePolicy,
 185                                         $policies[$group]
 186                                 );
 187                         }
 188                 }
 189
 190                 return $effectivePolicy;
 191         }
 192
 193         /**
 194          * Utility function to get a policy that is the most restrictive of $p1 and $p2. For
 195          * simplicity, we setup the policy values so the maximum value is always more restrictive.
 196          * It is also used recursively to merge settings within the same policy.
 197          * @param array $p1
 198          * @param array $p2
 199          * @return array containing the more restrictive values of $p1 and $p2
 200          */
 201         public static function maxOfPolicies( array $p1, array $p2 ) {
 202                 $ret = [];
 203                 $keys = array_merge( array_keys( $p1 ), array_keys( $p2 ) );
 204                 foreach ( $keys as $key ) {
 205                         if ( !isset( $p1[$key] ) ) {
 206                                 $ret[$key] = $p2[$key];
 207                         } elseif ( !isset( $p2[$key] ) ) {
 208                                 $ret[$key] = $p1[$key];
 209                         } elseif ( !is_array( $p1[$key] ) && !is_array( $p2[$key] ) ) {
 210                                 $ret[$key] = max( $p1[$key], $p2[$key] );
 211                         } else {
 212                                 if ( !is_array( $p1[$key] ) ) {
 213                                         $p1[$key] = [ 'value' => $p1[$key] ];
 214                                 } elseif ( !is_array( $p2[$key] ) ) {
 215                                         $p2[$key] = [ 'value' => $p2[$key] ];
 216                                 }
 217                                 $ret[$key] = self::maxOfPolicies( $p1[$key], $p2[$key] );
 218                         }
 219                 }
 220                 return $ret;
 221         }
 222
 223 }