activitypub / includes / class-router.php

class-router.php in ActivityPub 7.7.0, at includes/class-router.php

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1	<?php
2	/**
3	* Router class.
4	*
5	* @package Activitypub
6	*/
7
8	namespace Activitypub;
9
10	use Activitypub\Collection\Actors;
11	use Activitypub\Collection\Outbox;
12
13	/**
14	* Router class.
15	*/
16	class Router {
17	/**
18	* Initialize the class, registering WordPress hooks.
19	*/
20	public static function init() {
21	\add_action( 'init', array( self::class, 'add_rewrite_rules' ), 11 );
22
23	\add_filter( 'template_include', array( self::class, 'render_activitypub_template' ), 99 );
24	\add_action( 'template_redirect', array( self::class, 'template_redirect' ) );
25	\add_filter( 'redirect_canonical', array( self::class, 'redirect_canonical' ), 10, 2 );
26	\add_filter( 'redirect_canonical', array( self::class, 'no_trailing_redirect' ), 10, 2 );
27	\add_filter( 'query_vars', array( self::class, 'add_query_vars' ) );
28
29	\add_action( 'parse_query', array( self::class, 'fix_is_home_check' ) );
30	}
31
32	/**
33	* Add rewrite rules.
34	*/
35	public static function add_rewrite_rules() {
36	/*
37	* If another system needs to take precedence over the ActivityPub rewrite rules,
38	* they can define their own and will manually call the appropriate functions as required.
39	*/
40	if ( ACTIVITYPUB_DISABLE_REWRITES ) {
41	return;
42	}
43
44	if ( ! \class_exists( 'Webfinger' ) ) {
45	\add_rewrite_rule(
46	'^.well-known/webfinger',
47	'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/webfinger',
48	'top'
49	);
50	}
51
52	if ( ! \class_exists( 'Nodeinfo_Endpoint' ) && true === (bool) \get_option( 'blog_public', 1 ) ) {
53	\add_rewrite_rule(
54	'^.well-known/nodeinfo',
55	'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/nodeinfo',
56	'top'
57	);
58	}
59
60	\add_rewrite_rule( '^@([\w\-\.]+)\/?$', 'index.php?actor=$matches[1]', 'top' );
61	\add_rewrite_endpoint( 'activitypub', EP_AUTHORS \| EP_PERMALINK \| EP_PAGES );
62	}
63
64	/**
65	* Return a AS2 JSON version of an author, post or page.
66	*
67	* @param string $template The path to the template object.
68	*
69	* @return string The new path to the JSON template.
70	*/
71	public static function render_activitypub_template( $template ) {
72	if ( \wp_is_serving_rest_request() \|\| \wp_doing_ajax() ) {
73	return $template;
74	}
75
76	self::add_headers();
77
78	if ( ! is_activitypub_request() \|\| ! should_negotiate_content() ) {
79	if ( \get_query_var( 'p' ) && Outbox::POST_TYPE === \get_post_type( \get_query_var( 'p' ) ) ) {
80	\set_query_var( 'is_404', true );
81	\status_header( 406 );
82	}
83	return $template;
84	}
85
86	if ( Tombstone::exists_local( Query::get_instance()->get_request_url() ) ) {
87	\status_header( 410 );
88	return ACTIVITYPUB_PLUGIN_DIR . 'templates/tombstone-json.php';
89	}
90
91	$activitypub_template = false;
92	$activitypub_object = Query::get_instance()->get_activitypub_object();
93
94	if ( $activitypub_object ) {
95	if ( \get_query_var( 'preview' ) ) {
96	\define( 'ACTIVITYPUB_PREVIEW', true );
97
98	/**
99	* Filter the template used for the ActivityPub preview.
100	*
101	* @param string $activitypub_template Absolute path to the template file.
102	*/
103	$activitypub_template = apply_filters( 'activitypub_preview_template', ACTIVITYPUB_PLUGIN_DIR . '/templates/post-preview.php' );
104	} else {
105	$activitypub_template = ACTIVITYPUB_PLUGIN_DIR . 'templates/activitypub-json.php';
106	}
107	}
108
109	/*
110	* Check if the request is authorized.
111	*
112	* @see https://www.w3.org/wiki/SocialCG/ActivityPub/Primer/Authentication_Authorization#Authorized_fetch
113	* @see https://swicg.github.io/activitypub-http-signature/#authorized-fetch
114	*/
115	if ( $activitypub_template && use_authorized_fetch() ) {
116	$verification = Signature::verify_http_signature( $_SERVER );
117	if ( \is_wp_error( $verification ) ) {
118	\status_header( 401 );
119
120	// Fallback as template_loader can't return http headers.
121	return $template;
122	}
123	}
124
125	if ( $activitypub_template ) {
126	\set_query_var( 'is_404', false );
127
128	// Check if header already sent.
129	if ( ! \headers_sent() ) {
130	// Send 200 status header.
131	\status_header( 200 );
132	}
133
134	return $activitypub_template;
135	}
136
137	return $template;
138	}
139
140	/**
141	* Add the 'self' link to the header.
142	*/
143	public static function add_headers() {
144	$id = Query::get_instance()->get_activitypub_object_id();
145
146	if ( ! $id ) {
147	return;
148	}
149
150	if ( ! headers_sent() ) {
151	\header( 'Link: <' . esc_url( $id ) . '>; title="ActivityPub (JSON)"; rel="alternate"; type="application/activity+json"', false );
152
153	if ( \get_option( 'activitypub_vary_header', '1' ) ) {
154	// Send Vary header for Accept header.
155	\header( 'Vary: Accept', false );
156	}
157	}
158
159	add_action(
160	'wp_head',
161	function () use ( $id ) {
162	echo PHP_EOL . '<link rel="alternate" title="ActivityPub (JSON)" type="application/activity+json" href="' . esc_url( $id ) . '" />' . PHP_EOL;
163	}
164	);
165	}
166
167	/**
168	* Remove trailing slash from ActivityPub @username requests.
169	*
170	* @param string $redirect_url The URL to redirect to.
171	* @param string $requested_url The requested URL.
172	*
173	* @return string $redirect_url The possibly-unslashed redirect URL.
174	*/
175	public static function no_trailing_redirect( $redirect_url, $requested_url ) {
176	if ( get_query_var( 'actor' ) ) {
177	return $requested_url;
178	}
179
180	return $redirect_url;
181	}
182
183	/**
184	* Add support for `p` and `author` query vars.
185	*
186	* @param string $redirect_url The URL to redirect to.
187	* @param string $requested_url The requested URL.
188	*
189	* @return string $redirect_url
190	*/
191	public static function redirect_canonical( $redirect_url, $requested_url ) {
192	if ( ! is_activitypub_request() ) {
193	return $redirect_url;
194	}
195
196	$query = \wp_parse_url( $requested_url, PHP_URL_QUERY );
197
198	if ( ! $query ) {
199	return $redirect_url;
200	}
201
202	$query_params = \wp_parse_args( $query );
203	unset( $query_params['activitypub'] );
204	unset( $query_params['stamp'] );
205
206	if ( 1 !== count( $query_params ) ) {
207	return $redirect_url;
208	}
209
210	if ( isset( $query_params['p'] ) ) {
211	return null;
212	}
213
214	if ( isset( $query_params['author'] ) ) {
215	return null;
216	}
217
218	return $requested_url;
219	}
220
221	/**
222	* Custom redirects for ActivityPub requests.
223	*
224	* @return void
225	*/
226	public static function template_redirect() {
227	global $wp_query;
228
229	$comment_id = \get_query_var( 'c', null );
230
231	// Check if it seems to be a comment.
232	if ( $comment_id ) {
233	$comment = \get_comment( $comment_id );
234
235	// Load a 404-page if `c` is set but not valid.
236	if ( ! $comment ) {
237	$wp_query->set_404();
238	return;
239	}
240
241	// Stop if it's not an ActivityPub comment.
242	if ( is_activitypub_request() && ! is_local_comment( $comment ) ) {
243	return;
244	}
245
246	\wp_safe_redirect( get_comment_link( $comment ) );
247	exit;
248	}
249
250	$actor = \get_query_var( 'actor', null );
251	if ( $actor ) {
252	$actor = Actors::get_by_username( $actor );
253	if ( ! $actor \|\| \is_wp_error( $actor ) ) {
254	$wp_query->set_404();
255	return;
256	}
257
258	if ( is_activitypub_request() ) {
259	return;
260	}
261
262	\wp_safe_redirect( $actor->get_url(), 301 );
263	exit;
264	}
265	}
266
267	/**
268	* Add the 'activitypub' query variable so WordPress won't mangle it.
269	*
270	* @param array $vars The query variables.
271	*
272	* @return array The query variables.
273	*/
274	public static function add_query_vars( $vars ) {
275	$vars[] = 'activitypub';
276	$vars[] = 'preview';
277	$vars[] = 'author';
278	$vars[] = 'actor';
279	$vars[] = 'stamp';
280	$vars[] = 'type';
281	$vars[] = 'c';
282	$vars[] = 'p';
283
284	return $vars;
285	}
286
287	/**
288	* Optimize home page query for ActivityPub requests.
289	*
290	* Skip the database query entirely for ActivityPub requests on the home page
291	* since we only need to return the blog actor, not posts.
292	*
293	* @param \WP_Query $wp_query The WP_Query instance.
294	*/
295	public static function fix_is_home_check( $wp_query ) {
296	if (
297	$wp_query->get( 'actor' ) \|\|
298	$wp_query->get( 'stamp' ) \|\|
299	$wp_query->get( 'c' )
300	) {
301	$wp_query->is_home = false;
302	}
303	}
304	}
305