wikimedia/mediawiki-core

<?php
/**
 * A class to check request restrictions expressed as a JSON object
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 */

use MediaWiki\Json\FormatJson;
use MediaWiki\Linker\LinkTarget;
use MediaWiki\Request\WebRequest;
use MediaWiki\Status\Status;
use MediaWiki\Title\Title;
use Wikimedia\IPSet;
use Wikimedia\IPUtils;

/**
 * A class to check request restrictions expressed as a JSON object
 */
class MWRestrictions implements Stringable {

    /** @var string[] */
    private $ipAddresses = [ '0.0.0.0/0', '::/0' ];

    /** @var string[] */
    private $pages = [];

    public StatusValue $validity;

    /**
     * @param array|null $restrictions
     * @throws InvalidArgumentException
     */
    protected function __construct( array $restrictions = null ) {
        $this->validity = StatusValue::newGood();
        if ( $restrictions !== null ) {
            $this->loadFromArray( $restrictions );
        }
    }

    /**
     * @return MWRestrictions
     */
    public static function newDefault() {
        return new self();
    }

    /**
     * @param array $restrictions
     * @return MWRestrictions
     * @throws InvalidArgumentException
     */
    public static function newFromArray( array $restrictions ) {
        return new self( $restrictions );
    }

    /**
     * @param string $json JSON representation of the restrictions
     * @return MWRestrictions
     * @throws InvalidArgumentException
     */
    public static function newFromJson( $json ) {
        $restrictions = FormatJson::decode( $json, true );
        if ( !is_array( $restrictions ) ) {
            throw new InvalidArgumentException( 'Invalid restrictions JSON' );
        }
        return new self( $restrictions );
    }

    private function loadFromArray( array $restrictions ) {
        static $neededKeys = [ 'IPAddresses' ];

        $keys = array_keys( $restrictions );
        $missingKeys = array_diff( $neededKeys, $keys );
        if ( $missingKeys ) {
            throw new InvalidArgumentException(
                'Array is missing required keys: ' . implode( ', ', $missingKeys )
            );
        }

        if ( !is_array( $restrictions['IPAddresses'] ) ) {
            throw new InvalidArgumentException( 'IPAddresses is not an array' );
        }
        foreach ( $restrictions['IPAddresses'] as $ip ) {
            if ( !IPUtils::isIPAddress( $ip ) ) {
                $this->validity->fatal( 'restrictionsfield-badip', $ip );
            }
        }
        $this->ipAddresses = $restrictions['IPAddresses'];

        if ( isset( $restrictions['Pages'] ) ) {
            if ( !is_array( $restrictions['Pages'] ) ) {
                throw new InvalidArgumentException( 'Pages is not an array of page names' );
            }
            foreach ( $restrictions['Pages'] as $page ) {
                if ( !is_string( $page ) ) {
                    throw new InvalidArgumentException( "Pages contains non-string value: $page" );
                }
            }
            $this->pages = $restrictions['Pages'];
        }
    }

    /**
     * Return the restrictions as an array
     * @return array
     */
    public function toArray() {
        $arr = [ 'IPAddresses' => $this->ipAddresses ];
        if ( count( $this->pages ) ) {
            $arr['Pages'] = $this->pages;
        }
        return $arr;
    }

    /**
     * Return the restrictions as a JSON string
     * @param bool|string $pretty Pretty-print the JSON output, see FormatJson::encode
     * @return string
     */
    public function toJson( $pretty = false ) {
        return FormatJson::encode( $this->toArray(), $pretty, FormatJson::ALL_OK );
    }

    public function __toString() {
        return $this->toJson();
    }

    /**
     * Test against the passed WebRequest
     * @param WebRequest $request
     * @return Status
     */
    public function check( WebRequest $request ) {
        $ok = [
            'ip' => $this->checkIP( $request->getIP() ),
        ];
        $status = Status::newGood();
        $status->setResult( $ok === array_filter( $ok ), $ok );
        return $status;
    }

    /**
     * Test whether an action on the target is allowed by the restrictions
     *
     * @internal
     * @param LinkTarget $target
     * @return StatusValue
     */
    public function userCan( LinkTarget $target ) {
        if ( !$this->checkPage( $target ) ) {
            return StatusValue::newFatal( 'session-page-restricted' );
        }
        return StatusValue::newGood();
    }

    /**
     * Test if an IP address is allowed by the restrictions
     * @param string $ip
     * @return bool
     */
    public function checkIP( $ip ) {
        $set = new IPSet( $this->ipAddresses );
        return $set->match( $ip );
    }

    /**
     * Test if an action on a title is allowed by the restrictions
     *
     * @param LinkTarget $target
     * @return bool
     */
    private function checkPage( LinkTarget $target ) {
        if ( count( $this->pages ) === 0 ) {
            return true;
        }
        $pagesNormalized = array_map( static function ( $titleText ) {
            $title = Title::newFromText( $titleText );
            return $title ? $title->getPrefixedText() : '';
        }, $this->pages );
        return in_array( Title::newFromLinkTarget( $target )->getPrefixedText(), $pagesNormalized, true );
    }
}