wordpress-activitypub/includes/rest/class-webfinger.php
2023-01-27 15:48:28 +01:00

175 lines
4.8 KiB
PHP

<?php
namespace Activitypub\Rest;
/**
* ActivityPub WebFinger REST-Class
*
* @author Matthias Pfefferle
*
* @see https://webfinger.net/
*/
class Webfinger {
/**
* Initialize the class, registering WordPress hooks
*/
public static function init() {
\add_action( 'rest_api_init', array( '\Activitypub\Rest\Webfinger', 'register_routes' ) );
\add_action( 'webfinger_user_data', array( '\Activitypub\Rest\Webfinger', 'add_webfinger_discovery' ), 10, 3 );
}
/**
* Register routes
*/
public static function register_routes() {
\register_rest_route(
'activitypub/1.0',
'/webfinger',
array(
array(
'methods' => \WP_REST_Server::READABLE,
'callback' => array( '\Activitypub\Rest\Webfinger', 'webfinger' ),
'args' => self::request_parameters(),
'permission_callback' => '__return_true',
),
)
);
}
/**
* Render JRD file
*
* @param WP_REST_Request $request
* @return WP_REST_Response
*/
public static function webfinger( $request ) {
$resource = $request->get_param( 'resource' );
if ( \strpos( $resource, '@' ) === false ) {
return new \WP_Error( 'activitypub_unsupported_resource', \__( 'Resource is invalid', 'activitypub' ), array( 'status' => 400 ) );
}
$resource = \str_replace( 'acct:', '', $resource );
$resource_identifier = \substr( $resource, 0, \strrpos( $resource, '@' ) );
$resource_host = \substr( \strrchr( $resource, '@' ), 1 );
if ( \wp_parse_url( \home_url( '/' ), \PHP_URL_HOST ) !== $resource_host ) {
return new \WP_Error( 'activitypub_wrong_host', \__( 'Resource host does not match blog host', 'activitypub' ), array( 'status' => 404 ) );
}
$user = \get_user_by( 'login', \esc_sql( $resource_identifier ) );
if ( ! $user || ! user_can( $user, 'publish_posts' ) ) {
return new \WP_Error( 'activitypub_user_not_found', \__( 'User not found', 'activitypub' ), array( 'status' => 404 ) );
}
$json = array(
'subject' => $resource,
'aliases' => array(
\get_author_posts_url( $user->ID ),
),
'links' => array(
array(
'rel' => 'self',
'type' => 'application/activity+json',
'href' => \get_author_posts_url( $user->ID ),
),
array(
'rel' => 'http://webfinger.net/rel/profile-page',
'type' => 'text/html',
'href' => \get_author_posts_url( $user->ID ),
),
),
);
return new \WP_REST_Response( $json, 200 );
}
/**
* The supported parameters
*
* @return array list of parameters
*/
public static function request_parameters() {
$params = array();
$params['resource'] = array(
'required' => true,
'type' => 'string',
'pattern' => '^acct:(.+)@(.+)$',
);
return $params;
}
/**
* Add WebFinger discovery links
*
* @param array $array the jrd array
* @param string $resource the WebFinger resource
* @param WP_User $user the WordPress user
*/
public static function add_webfinger_discovery( $array, $resource, $user ) {
$array['links'][] = array(
'rel' => 'self',
'type' => 'application/activity+json',
'href' => \get_author_posts_url( $user->ID ),
);
return $array;
}
public static function resolve( $account ) {
if ( ! preg_match( '/^@?' . ACTIVITYPUB_USERNAME_REGEXP . '$/i', $account, $m ) ) {
return null;
}
$transient_key = 'activitypub_resolve_' . ltrim( $account, '@' );
$link = \get_transient( $transient_key );
if ( $link ) {
return $link;
}
$url = \add_query_arg( 'resource', 'acct:' . ltrim( $account, '@' ), 'https://' . $m[1] . '/.well-known/webfinger' );
if ( ! \wp_http_validate_url( $url ) ) {
return new \WP_Error( 'invalid_webfinger_url', null, $url );
}
// try to access author URL
$response = \wp_remote_get(
$url,
array(
'headers' => array( 'Accept' => 'application/activity+json' ),
'redirection' => 0,
)
);
if ( \is_wp_error( $response ) ) {
$link = new \WP_Error( 'webfinger_url_not_accessible', null, $url );
\set_transient( $transient_key, $link, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
return $link;
}
$response_code = \wp_remote_retrieve_response_code( $response );
$body = \wp_remote_retrieve_body( $response );
$body = \json_decode( $body, true );
if ( ! isset( $body['links'] ) ) {
$link = new \WP_Error( 'webfinger_url_invalid_response', null, $url );
\set_transient( $transient_key, $link, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
return $link;
}
foreach ( $body['links'] as $link ) {
if ( 'self' === $link['rel'] && 'application/activity+json' === $link['type'] ) {
\set_transient( $transient_key, $link['href'], WEEK_IN_SECONDS );
return $link['href'];
}
}
$link = new \WP_Error( 'webfinger_url_no_activity_pub', null, $body );
\set_transient( $transient_key, $link, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
return $link;
}
}