activitypub / includes / functions.php

functions.php in ActivityPub 1.0.7, at includes/functions.php

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1	<?php
2	namespace Activitypub;
3
4	use WP_Error;
5	use Activitypub\Http;
6	use Activitypub\Activity\Activity;
7	use Activitypub\Collection\Followers;
8
9	/**
10	* Returns the ActivityPub default JSON-context
11	*
12	* @return array the activitypub context
13	*/
14	function get_context() {
15	$context = Activity::CONTEXT;
16
17	return \apply_filters( 'activitypub_json_context', $context );
18	}
19
20	function safe_remote_post( $url, $body, $user_id ) {
21	return Http::post( $url, $body, $user_id );
22	}
23
24	function safe_remote_get( $url ) {
25	return Http::get( $url );
26	}
27
28	/**
29	* Returns a users WebFinger "resource"
30	*
31	* @param int $user_id The User-ID.
32	*
33	* @return string The User-Resource.
34	*/
35	function get_webfinger_resource( $user_id ) {
36	return Webfinger::get_user_resource( $user_id );
37	}
38
39	/**
40	* Requests the Meta-Data from the Actors profile
41	*
42	* @param string $actor The Actor URL.
43	* @param bool $cached If the result should be cached.
44	*
45	* @return array The Actor profile as array
46	*/
47	function get_remote_metadata_by_actor( $actor, $cached = true ) {
48	$pre = apply_filters( 'pre_get_remote_metadata_by_actor', false, $actor );
49	if ( $pre ) {
50	return $pre;
51	}
52	if ( preg_match( '/^@?' . ACTIVITYPUB_USERNAME_REGEXP . '$/i', $actor ) ) {
53	$actor = Webfinger::resolve( $actor );
54	}
55
56	if ( ! $actor ) {
57	return new WP_Error( 'activitypub_no_valid_actor_identifier', \__( 'The "actor" identifier is not valid', 'activitypub' ), array( 'status' => 404, 'actor' => $actor ) );
58	}
59
60	if ( is_wp_error( $actor ) ) {
61	return $actor;
62	}
63
64	$transient_key = 'activitypub_' . $actor;
65
66	// only check the cache if needed.
67	if ( $cached ) {
68	$metadata = \get_transient( $transient_key );
69
70	if ( $metadata ) {
71	return $metadata;
72	}
73	}
74
75	if ( ! \wp_http_validate_url( $actor ) ) {
76	$metadata = new WP_Error( 'activitypub_no_valid_actor_url', \__( 'The "actor" is no valid URL', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
77	\set_transient( $transient_key, $metadata, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
78	return $metadata;
79	}
80
81	$short_timeout = function() {
82	return 3;
83	};
84	add_filter( 'activitypub_remote_get_timeout', $short_timeout );
85	$response = Http::get( $actor );
86	remove_filter( 'activitypub_remote_get_timeout', $short_timeout );
87	if ( \is_wp_error( $response ) ) {
88	\set_transient( $transient_key, $response, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
89	return $response;
90	}
91
92	$metadata = \wp_remote_retrieve_body( $response );
93	$metadata = \json_decode( $metadata, true );
94
95	\set_transient( $transient_key, $metadata, WEEK_IN_SECONDS );
96
97	if ( ! $metadata ) {
98	$metadata = new WP_Error( 'activitypub_invalid_json', \__( 'No valid JSON data', 'activitypub' ), array( 'status' => 400, 'actor' => $actor ) );
99	\set_transient( $transient_key, $metadata, HOUR_IN_SECONDS ); // Cache the error for a shorter period.
100	return $metadata;
101	}
102
103	return $metadata;
104	}
105
106	/**
107	* Returns the followers of a given user.
108	*
109	* @param int $user_id The User-ID.
110	*
111	* @return array The followers.
112	*/
113	function get_followers( $user_id ) {
114	return Followers::get_followers( $user_id );
115	}
116
117	/**
118	* Count the number of followers for a given user.
119	*
120	* @param int $user_id The User-ID.
121	*
122	* @return int The number of followers.
123	*/
124	function count_followers( $user_id ) {
125	return Followers::count_followers( $user_id );
126	}
127
128	/**
129	* Examine a url and try to determine the author ID it represents.
130	*
131	* Checks are supposedly from the hosted site blog.
132	*
133	* @param string $url Permalink to check.
134	*
135	* @return int User ID, or 0 on failure.
136	*/
137	function url_to_authorid( $url ) {
138	global $wp_rewrite;
139
140	// check if url hase the same host
141	if ( \wp_parse_url( \site_url(), \PHP_URL_HOST ) !== \wp_parse_url( $url, \PHP_URL_HOST ) ) {
142	return 0;
143	}
144
145	// first, check to see if there is a 'author=N' to match against
146	if ( \preg_match( '/[?&]author=(\d+)/i', $url, $values ) ) {
147	$id = \absint( $values[1] );
148	if ( $id ) {
149	return $id;
150	}
151	}
152
153	// check to see if we are using rewrite rules
154	$rewrite = $wp_rewrite->wp_rewrite_rules();
155
156	// not using rewrite rules, and 'author=N' method failed, so we're out of options
157	if ( empty( $rewrite ) ) {
158	return 0;
159	}
160
161	// generate rewrite rule for the author url
162	$author_rewrite = $wp_rewrite->get_author_permastruct();
163	$author_regexp = \str_replace( '%author%', '', $author_rewrite );
164
165	// match the rewrite rule with the passed url
166	if ( \preg_match( '/https?:\/\/(.+)' . \preg_quote( $author_regexp, '/' ) . '([^\/]+)/i', $url, $match ) ) {
167	$user = \get_user_by( 'slug', $match[2] );
168	if ( $user ) {
169	return $user->ID;
170	}
171	}
172
173	return 0;
174	}
175
176	/**
177	* Check for Tombstone Objects
178	*
179	* @see https://www.w3.org/TR/activitypub/#delete-activity-outbox
180	*
181	* @param WP_Error $wp_error A WP_Error-Response of an HTTP-Request
182	*
183	* @return boolean true if HTTP-Code is 410 or 404
184	*/
185	function is_tombstone( $wp_error ) {
186	if ( ! is_wp_error( $wp_error ) ) {
187	return false;
188	}
189
190	if ( in_array( (int) $wp_error->get_error_code(), array( 404, 410 ), true ) ) {
191	return true;
192	}
193
194	return false;
195	}
196
197	/**
198	* Get the REST URL relative to this plugin's namespace.
199	*
200	* @param string $path Optional. REST route path. Otherwise this plugin's namespaced root.
201	*
202	* @return string REST URL relative to this plugin's namespace.
203	*/
204	function get_rest_url_by_path( $path = '' ) {
205	// we'll handle the leading slash.
206	$path = ltrim( $path, '/' );
207	$namespaced_path = sprintf( '/%s/%s', ACTIVITYPUB_REST_NAMESPACE, $path );
208	return \get_rest_url( null, $namespaced_path );
209	}
210
211	/**
212	* Convert a string from camelCase to snake_case.
213	*
214	* @param string $string The string to convert.
215	*
216	* @return string The converted string.
217	*/
218	// phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
219	function camel_to_snake_case( $string ) {
220	return strtolower( preg_replace( '/(?<!^)[A-Z]/', '_$0', $string ) );
221	}
222
223	/**
224	* Convert a string from snake_case to camelCase.
225	*
226	* @param string $string The string to convert.
227	*
228	* @return string The converted string.
229	*/
230	// phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
231	function snake_to_camel_case( $string ) {
232	return lcfirst( str_replace( '_', '', ucwords( $string, '_' ) ) );
233	}
234
235	/**
236	* Escapes a Tag, to be used as a hashtag.
237	*
238	* @param string $string The string to escape.
239	*
240	* @return string The escaped hastag.
241	*/
242	function esc_hashtag( $string ) {
243
244	$hashtag = \wp_specialchars_decode( $string, ENT_QUOTES );
245	// Remove all characters that are not letters, numbers, or underscores.
246	$hashtag = \preg_replace( '/emoji-regex(*SKIP)(?!)\|[^\p{L}\p{Nd}_]+/u', '_', $hashtag );
247
248	// Capitalize every letter that is preceded by an underscore.
249	$hashtag = preg_replace_callback(
250	'/_(.)/',
251	function ( $matches ) {
252	return '' . strtoupper( $matches[1] );
253	},
254	$hashtag
255	);
256
257	// Add a hashtag to the beginning of the string.
258	$hashtag = ltrim( $hashtag, '#' );
259	$hashtag = '#' . $hashtag;
260
261	/**
262	* Allow defining your own custom hashtag generation rules.
263	*
264	* @param string $hashtag The hashtag to be returned.
265	* @param string $string The original string.
266	*/
267	$hashtag = apply_filters( 'activitypub_esc_hashtag', $hashtag, $string );
268
269	return esc_html( $hashtag );
270	}
271
272	/**
273	* Check if a request is for an ActivityPub request.
274	*
275	* @return bool False by default.
276	*/
277	function is_activitypub_request() {
278	global $wp_query;
279
280	/*
281	* ActivityPub requests are currently only made for
282	* author archives, singular posts, and the homepage.
283	*/
284	if ( ! \is_author() && ! \is_singular() && ! \is_home() && ! defined( '\REST_REQUEST' ) ) {
285	return false;
286	}
287
288	// One can trigger an ActivityPub request by adding ?activitypub to the URL.
289	// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.VariableRedeclaration
290	global $wp_query;
291	if ( isset( $wp_query->query_vars['activitypub'] ) ) {
292	return true;
293	}
294
295	/*
296	* The other (more common) option to make an ActivityPub request
297	* is to send an Accept header.
298	*/
299	if ( isset( $_SERVER['HTTP_ACCEPT'] ) ) {
300	$accept = sanitize_text_field( wp_unslash( $_SERVER['HTTP_ACCEPT'] ) );
301
302	/*
303	* $accept can be a single value, or a comma separated list of values.
304	* We want to support both scenarios,
305	* and return true when the header includes at least one of the following:
306	* - application/activity+json
307	* - application/ld+json
308	* - application/json
309	*/
310	if ( preg_match( '/(application\/(ld\+json\|activity\+json\|json))/i', $accept ) ) {
311	return true;
312	}
313	}
314
315	return false;
316	}
317
318	/**
319	* This function checks if a user is disabled for ActivityPub.
320	*
321	* @param int $user_id The User-ID.
322	*
323	* @return boolean True if the user is disabled, false otherwise.
324	*/
325	function is_user_disabled( $user_id ) {
326	$return = false;
327
328	switch ( $user_id ) {
329	// if the user is the application user, it's always enabled.
330	case \Activitypub\Collection\Users::APPLICATION_USER_ID:
331	$return = false;
332	break;
333	// if the user is the blog user, it's only enabled in single-user mode.
334	case \Activitypub\Collection\Users::BLOG_USER_ID:
335	if ( is_user_type_disabled( 'blog' ) ) {
336	$return = true;
337	break;
338	}
339
340	$return = false;
341	break;
342	// if the user is any other user, it's enabled if it can publish posts.
343	default:
344	if ( ! \get_user_by( 'id', $user_id ) ) {
345	$return = true;
346	break;
347	}
348
349	if ( is_user_type_disabled( 'user' ) ) {
350	$return = true;
351	break;
352	}
353
354	if ( ! \user_can( $user_id, 'publish_posts' ) ) {
355	$return = true;
356	break;
357	}
358
359	$return = false;
360	break;
361	}
362
363	return apply_filters( 'activitypub_is_user_disabled', $return, $user_id );
364	}
365
366	/**
367	* Checks if a User-Type is disabled for ActivityPub.
368	*
369	* This function is used to check if the 'blog' or 'user'
370	* type is disabled for ActivityPub.
371	*
372	* @param enum $type Can be 'blog' or 'user'.
373	*
374	* @return boolean True if the user type is disabled, false otherwise.
375	*/
376	function is_user_type_disabled( $type ) {
377	switch ( $type ) {
378	case 'blog':
379	if ( \defined( 'ACTIVITYPUB_SINGLE_USER_MODE' ) ) {
380	if ( ACTIVITYPUB_SINGLE_USER_MODE ) {
381	$return = false;
382	break;
383	}
384	}
385
386	if ( \defined( 'ACTIVITYPUB_DISABLE_BLOG_USER' ) ) {
387	$return = ACTIVITYPUB_DISABLE_BLOG_USER;
388	break;
389	}
390
391	if ( '1' !== \get_option( 'activitypub_enable_blog_user', '0' ) ) {
392	$return = true;
393	break;
394	}
395
396	$return = false;
397	break;
398	case 'user':
399	if ( \defined( 'ACTIVITYPUB_SINGLE_USER_MODE' ) ) {
400	if ( ACTIVITYPUB_SINGLE_USER_MODE ) {
401	$return = true;
402	break;
403	}
404	}
405
406	if ( \defined( 'ACTIVITYPUB_DISABLE_USER' ) ) {
407	$return = ACTIVITYPUB_DISABLE_USER;
408	break;
409	}
410
411	if ( '1' !== \get_option( 'activitypub_enable_users', '1' ) ) {
412	$return = true;
413	break;
414	}
415
416	$return = false;
417	break;
418	default:
419	$return = new WP_Error( 'activitypub_wrong_user_type', __( 'Wrong user type', 'activitypub' ), array( 'status' => 400 ) );
420	break;
421	}
422
423	return apply_filters( 'activitypub_is_user_type_disabled', $return, $type );
424	}
425
426	/**
427	* Check if the blog is in single-user mode.
428	*
429	* @return boolean True if the blog is in single-user mode, false otherwise.
430	*/
431	function is_single_user() {
432	if (
433	false === is_user_type_disabled( 'blog' ) &&
434	true === is_user_type_disabled( 'user' )
435	) {
436	return true;
437	}
438
439	return false;
440	}
441
442	/**
443	* Check if a site supports the block editor.
444	*
445	* @return boolean True if the site supports the block editor, false otherwise.
446	*/
447	function site_supports_blocks() {
448	if ( \version_compare( \get_bloginfo( 'version' ), '5.9', '<' ) ) {
449	return false;
450	}
451
452	if ( ! \function_exists( 'register_block_type_from_metadata' ) ) {
453	return false;
454	}
455
456	/**
457	* Allow plugins to disable block editor support,
458	* thus disabling blocks registered by the ActivityPub plugin.
459	*
460	* @param boolean $supports_blocks True if the site supports the block editor, false otherwise.
461	*/
462	return apply_filters( 'activitypub_site_supports_blocks', true );
463	}
464
465	/**
466	* Check if data is valid JSON.
467	*
468	* @param string $data The data to check.
469	*
470	* @return boolean True if the data is JSON, false otherwise.
471	*/
472	function is_json( $data ) {
473	return \is_array( \json_decode( $data, true ) ) ? true : false;
474	}
475
476	/**
477	* Check if a blog is public based on the `blog_public` option
478	*
479	* @return bollean True if public, false if not
480	*/
481	function is_blog_public() {
482	return (bool) apply_filters( 'activitypub_is_blog_public', \get_option( 'blog_public', 1 ) );
483	}
484