Move FSFile classes to /fsfile

[mediawiki.git] / includes / auth / AuthenticationRequest.php

<?php
/**
 * Authentication request value 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
 *
 * @file
 * @ingroup Auth
 */

namespace MediaWiki\Auth;

use Message;

/**
 * This is a value object for authentication requests.
 *
 * An AuthenticationRequest represents a set of form fields that are needed on
 * and provided from a login, account creation, password change or similar form.
 *
 * @ingroup Auth
 * @since 1.27
 */
abstract class AuthenticationRequest {

        /** Indicates that the request is not required for authentication to proceed. */
        const OPTIONAL = 0;

        /** Indicates that the request is required for authentication to proceed.
         * This will only be used for UI purposes; it is the authentication providers'
         * responsibility to verify that all required requests are present.
         */
        const REQUIRED = 1;

        /** Indicates that the request is required by a primary authentication
         * provider. Since the user can choose which primary to authenticate with,
         * the request might or might not end up being actually required. */
        const PRIMARY_REQUIRED = 2;

        /** @var string|null The AuthManager::ACTION_* constant this request was
         * created to be used for. The *_CONTINUE constants are not used here, the
         * corresponding "begin" constant is used instead.
         */
        public $action = null;

        /** @var int For login, continue, and link actions, one of self::OPTIONAL,
         * self::REQUIRED, or self::PRIMARY_REQUIRED */
        public $required = self::REQUIRED;

        /** @var string|null Return-to URL, in case of redirect */
        public $returnToUrl = null;

        /** @var string|null Username. See AuthenticationProvider::getAuthenticationRequests()
         * for details of what this means and how it behaves. */
        public $username = null;

        /**
         * Supply a unique key for deduplication
         *
         * When the AuthenticationRequests instances returned by the providers are
         * merged, the value returned here is used for keeping only one copy of
         * duplicate requests.
         *
         * Subclasses should override this if multiple distinct instances would
         * make sense, i.e. the request class has internal state of some sort.
         *
         * This value might be exposed to the user in web forms so it should not
         * contain private information.
         *
         * @return string
         */
        public function getUniqueId() {
                return get_called_class();
        }

        /**
         * Fetch input field info
         *
         * The field info is an associative array mapping field names to info
         * arrays. The info arrays have the following keys:
         *  - type: (string) Type of input. Types and equivalent HTML widgets are:
         *     - string: <input type="text">
         *     - password: <input type="password">
         *     - select: <select>
         *     - checkbox: <input type="checkbox">
         *     - multiselect: More a grid of checkboxes than <select multi>
         *     - button: <input type="submit"> (uses 'label' as button text)
         *     - hidden: Not visible to the user, but needs to be preserved for the next request
         *     - null: No widget, just display the 'label' message.
         *  - options: (array) Maps option values to Messages for the
         *      'select' and 'multiselect' types.
         *  - value: (string) Value (for 'null' and 'hidden') or default value (for other types).
         *  - label: (Message) Text suitable for a label in an HTML form
         *  - help: (Message) Text suitable as a description of what the field is
         *  - optional: (bool) If set and truthy, the field may be left empty
         *  - sensitive: (bool) If set and truthy, the field is considered sensitive. Code using the
         *      request should avoid exposing the value of the field.
         *
         * All AuthenticationRequests are populated from the same data, so most of the time you'll
         * want to prefix fields names with something unique to the extension/provider (although
         * in some cases sharing the field with other requests is the right thing to do, e.g. for
         * a 'password' field).
         *
         * @return array As above
         */
        abstract public function getFieldInfo();

        /**
         * Returns metadata about this request.
         *
         * This is mainly for the benefit of API clients which need more detailed render hints
         * than what's available through getFieldInfo(). Semantics are unspecified and left to the
         * individual subclasses, but the contents of the array should be primitive types so that they
         * can be transformed into JSON or similar formats.
         *
         * @return array A (possibly nested) array with primitive types
         */
        public function getMetadata() {
                return [];
        }

        /**
         * Initialize form submitted form data.
         *
         * The default behavior is to to check for each key of self::getFieldInfo()
         * in the submitted data, and copy the value - after type-appropriate transformations -
         * to $this->$key. Most subclasses won't need to override this; if you do override it,
         * make sure to always return false if self::getFieldInfo() returns an empty array.
         *
         * @param array $data Submitted data as an associative array (keys will correspond
         *   to getFieldInfo())
         * @return bool Whether the request data was successfully loaded
         */
        public function loadFromSubmission( array $data ) {
                $fields = array_filter( $this->getFieldInfo(), function ( $info ) {
                        return $info['type'] !== 'null';
                } );
                if ( !$fields ) {
                        return false;
                }

                foreach ( $fields as $field => $info ) {
                        // Checkboxes and buttons are special. Depending on the method used
                        // to populate $data, they might be unset meaning false or they
                        // might be boolean. Further, image buttons might submit the
                        // coordinates of the click rather than the expected value.
                        if ( $info['type'] === 'checkbox' || $info['type'] === 'button' ) {
                                $this->$field = isset( $data[$field] ) && $data[$field] !== false
                                        || isset( $data["{$field}_x"] ) && $data["{$field}_x"] !== false;
                                if ( !$this->$field && empty( $info['optional'] ) ) {
                                        return false;
                                }
                                continue;
                        }

                        // Multiselect are too, slightly
                        if ( !isset( $data[$field] ) && $info['type'] === 'multiselect' ) {
                                $data[$field] = [];
                        }

                        if ( !isset( $data[$field] ) ) {
                                return false;
                        }
                        if ( $data[$field] === '' || $data[$field] === [] ) {
                                if ( empty( $info['optional'] ) ) {
                                        return false;
                                }
                        } else {
                                switch ( $info['type'] ) {
                                        case 'select':
                                                if ( !isset( $info['options'][$data[$field]] ) ) {
                                                        return false;
                                                }
                                                break;

                                        case 'multiselect':
                                                $data[$field] = (array)$data[$field];
                                                $allowed = array_keys( $info['options'] );
                                                if ( array_diff( $data[$field], $allowed ) !== [] ) {
                                                        return false;
                                                }
                                                break;
                                }
                        }

                        $this->$field = $data[$field];
                }

                return true;
        }

        /**
         * Describe the credentials represented by this request
         *
         * This is used on requests returned by
         * AuthenticationProvider::getAuthenticationRequests() for ACTION_LINK
         * and ACTION_REMOVE and for requests returned in
         * AuthenticationResponse::$linkRequest to create useful user interfaces.
         *
         * @return Message[] with the following keys:
         *  - provider: A Message identifying the service that provides
         *    the credentials, e.g. the name of the third party authentication
         *    service.
         *  - account: A Message identifying the credentials themselves,
         *    e.g. the email address used with the third party authentication
         *    service.
         */
        public function describeCredentials() {
                return [
                        'provider' => new \RawMessage( '$1', [ get_called_class() ] ),
                        'account' => new \RawMessage( '$1', [ $this->getUniqueId() ] ),
                ];
        }

        /**
         * Update a set of requests with form submit data, discarding ones that fail
         * @param AuthenticationRequest[] $reqs
         * @param array $data
         * @return AuthenticationRequest[]
         */
        public static function loadRequestsFromSubmission( array $reqs, array $data ) {
                return array_values( array_filter( $reqs, function ( $req ) use ( $data ) {
                        return $req->loadFromSubmission( $data );
                } ) );
        }

        /**
         * Select a request by class name.
         * @param AuthenticationRequest[] $reqs
         * @param string $class Class name
         * @param bool $allowSubclasses If true, also returns any request that's a subclass of the given
         *   class.
         * @return AuthenticationRequest|null Returns null if there is not exactly
         *  one matching request.
         */
        public static function getRequestByClass( array $reqs, $class, $allowSubclasses = false ) {
                $requests = array_filter( $reqs, function ( $req ) use ( $class, $allowSubclasses ) {
                        if ( $allowSubclasses ) {
                                return is_a( $req, $class, false );
                        } else {
                                return get_class( $req ) === $class;
                        }
                } );
                return count( $requests ) === 1 ? reset( $requests ) : null;
        }

        /**
         * Get the username from the set of requests
         *
         * Only considers requests that have a "username" field.
         *
         * @param AuthenticationRequest[] $reqs
         * @return string|null
         * @throws \UnexpectedValueException If multiple different usernames are present.
         */
        public static function getUsernameFromRequests( array $reqs ) {
                $username = null;
                $otherClass = null;
                foreach ( $reqs as $req ) {
                        $info = $req->getFieldInfo();
                        if ( $info && array_key_exists( 'username', $info ) && $req->username !== null ) {
                                if ( $username === null ) {
                                        $username = $req->username;
                                        $otherClass = get_class( $req );
                                } elseif ( $username !== $req->username ) {
                                        $requestClass = get_class( $req );
                                        throw new \UnexpectedValueException( "Conflicting username fields: \"{$req->username}\" from "
                                                . "$requestClass::\$username vs. \"$username\" from $otherClass::\$username" );
                                }
                        }
                }
                return $username;
        }

        /**
         * Merge the output of multiple AuthenticationRequest::getFieldInfo() calls.
         * @param AuthenticationRequest[] $reqs
         * @return array
         * @throws \UnexpectedValueException If fields cannot be merged
         */
        public static function mergeFieldInfo( array $reqs ) {
                $merged = [];

                // fields that are required by some primary providers but not others are not actually required
                $primaryRequests = array_filter( $reqs, function ( $req ) {
                        return $req->required === AuthenticationRequest::PRIMARY_REQUIRED;
                } );
                $sharedRequiredPrimaryFields = array_reduce( $primaryRequests, function ( $shared, $req ) {
                        $required = array_keys( array_filter( $req->getFieldInfo(), function ( $options ) {
                                return empty( $options['optional'] );
                        } ) );
                        if ( $shared === null ) {
                                return $required;
                        } else {
                                return array_intersect( $shared, $required );
                        }
                }, null );

                foreach ( $reqs as $req ) {
                        $info = $req->getFieldInfo();
                        if ( !$info ) {
                                continue;
                        }

                        foreach ( $info as $name => $options ) {
                                if (
                                        // If the request isn't required, its fields aren't required either.
                                        $req->required === self::OPTIONAL
                                        // If there is a primary not requiring this field, no matter how many others do,
                                        // authentication can proceed without it.
                                        || $req->required === self::PRIMARY_REQUIRED
                                                && !in_array( $name, $sharedRequiredPrimaryFields, true )
                                ) {
                                        $options['optional'] = true;
                                } else {
                                        $options['optional'] = !empty( $options['optional'] );
                                }

                                $options['sensitive'] = !empty( $options['sensitive'] );

                                if ( !array_key_exists( $name, $merged ) ) {
                                        $merged[$name] = $options;
                                } elseif ( $merged[$name]['type'] !== $options['type'] ) {
                                        throw new \UnexpectedValueException( "Field type conflict for \"$name\", " .
                                                "\"{$merged[$name]['type']}\" vs \"{$options['type']}\""
                                        );
                                } else {
                                        if ( isset( $options['options'] ) ) {
                                                if ( isset( $merged[$name]['options'] ) ) {
                                                        $merged[$name]['options'] += $options['options'];
                                                } else {
                                                        // @codeCoverageIgnoreStart
                                                        $merged[$name]['options'] = $options['options'];
                                                        // @codeCoverageIgnoreEnd
                                                }
                                        }

                                        $merged[$name]['optional'] = $merged[$name]['optional'] && $options['optional'];
                                        $merged[$name]['sensitive'] = $merged[$name]['sensitive'] || $options['sensitive'];

                                        // No way to merge 'value', 'image', 'help', or 'label', so just use
                                        // the value from the first request.
                                }
                        }
                }

                return $merged;
        }

        /**
         * Implementing this mainly for use from the unit tests.
         * @param array $data
         * @return AuthenticationRequest
         */
        public static function __set_state( $data ) {
                $ret = new static();
                foreach ( $data as $k => $v ) {
                        $ret->$k = $v;
                }
                return $ret;
        }
}