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

84 lines
2.4 KiB
PHP

<?php
namespace Activitypub;
/**
* ActivityPub WebFinger Class
*
* @author Matthias Pfefferle
*
* @see https://webfinger.net/
*/
class Webfinger {
/**
* Returns a users WebFinger "resource"
*
* @param int $user_id
*
* @return string The user-resource
*/
public static function get_user_resource( $user_id ) {
// use WebFinger plugin if installed
if ( \function_exists( '\get_webfinger_resource' ) ) {
return \get_webfinger_resource( $user_id, false );
}
$user = \get_user_by( 'id', $user_id );
return $user->user_login . '@' . \wp_parse_url( \home_url(), \PHP_URL_HOST );
}
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 ) ) {
$response = new \WP_Error( 'invalid_webfinger_url', null, $url );
\set_transient( $transient_key, $response, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
return $response;
}
// try to access author URL
$response = \wp_remote_get(
$url,
array(
'headers' => array( 'Accept' => 'application/activity+json' ),
'redirection' => 0,
'timeout' => 2,
)
);
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;
}
$body = \wp_remote_retrieve_body( $response );
$body = \json_decode( $body, true );
if ( empty( $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;
}
}