| 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_action( 'send_headers', array( self::class, 'add_headers' ) ); |
| 24 |
\add_filter( 'template_include', array( self::class, 'render_activitypub_template' ), 99 ); |
| 25 |
\add_action( 'template_redirect', array( self::class, 'template_redirect' ) ); |
| 26 |
\add_filter( 'redirect_canonical', array( self::class, 'redirect_canonical' ), 10, 2 ); |
| 27 |
\add_filter( 'redirect_canonical', array( self::class, 'no_trailing_redirect' ), 10, 2 ); |
| 28 |
\add_filter( 'query_vars', array( self::class, 'add_query_vars' ) ); |
| 29 |
|
| 30 |
\add_action( 'parse_query', array( self::class, 'fix_is_home_check' ) ); |
| 31 |
} |
| 32 |
|
| 33 |
/** |
| 34 |
* Add rewrite rules. |
| 35 |
*/ |
| 36 |
public static function add_rewrite_rules() { |
| 37 |
/* |
| 38 |
* If another system needs to take precedence over the ActivityPub rewrite rules, |
| 39 |
* they can define their own and will manually call the appropriate functions as required. |
| 40 |
*/ |
| 41 |
if ( ACTIVITYPUB_DISABLE_REWRITES ) { |
| 42 |
return; |
| 43 |
} |
| 44 |
|
| 45 |
\add_rewrite_rule( |
| 46 |
'^authorize_interaction/?$', |
| 47 |
'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/interactions', |
| 48 |
'top' |
| 49 |
); |
| 50 |
|
| 51 |
if ( ! \class_exists( 'Webfinger' ) ) { |
| 52 |
\add_rewrite_rule( |
| 53 |
'^.well-known/webfinger', |
| 54 |
'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/webfinger', |
| 55 |
'top' |
| 56 |
); |
| 57 |
} |
| 58 |
|
| 59 |
if ( ! \class_exists( 'Nodeinfo_Endpoint' ) && true === (bool) \get_option( 'blog_public', 1 ) ) { |
| 60 |
\add_rewrite_rule( |
| 61 |
'^.well-known/nodeinfo', |
| 62 |
'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/nodeinfo', |
| 63 |
'top' |
| 64 |
); |
| 65 |
} |
| 66 |
|
| 67 |
// Authorization Server Metadata (RFC 8414). |
| 68 |
\add_rewrite_rule( |
| 69 |
'^.well-known/oauth-authorization-server', |
| 70 |
'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/oauth/authorization-server-metadata', |
| 71 |
'top' |
| 72 |
); |
| 73 |
|
| 74 |
// Must precede the generic @username rule, which would otherwise match "application" as an actor username. |
| 75 |
\add_rewrite_rule( '^@application\/?$', 'index.php?rest_route=/' . ACTIVITYPUB_REST_NAMESPACE . '/application', 'top' ); |
| 76 |
\add_rewrite_rule( '^@([\w\-\.]+)\/?$', 'index.php?actor=$matches[1]', 'top' ); |
| 77 |
\add_rewrite_endpoint( 'activitypub', EP_AUTHORS | EP_PERMALINK | EP_PAGES ); |
| 78 |
} |
| 79 |
|
| 80 |
/** |
| 81 |
* Return a AS2 JSON version of an author, post or page. |
| 82 |
* |
| 83 |
* @param string $template The path to the template object. |
| 84 |
* |
| 85 |
* @return string The new path to the JSON template. |
| 86 |
*/ |
| 87 |
public static function render_activitypub_template( $template ) { |
| 88 |
if ( \wp_is_serving_rest_request() || \wp_doing_ajax() ) { |
| 89 |
return $template; |
| 90 |
} |
| 91 |
|
| 92 |
if ( ! is_activitypub_request() || ! should_negotiate_content() ) { |
| 93 |
$is_outbox_item = \get_query_var( 'p' ) && Outbox::POST_TYPE === \get_post_type( \get_query_var( 'p' ) ); |
| 94 |
$is_preflight = isset( $_SERVER['REQUEST_METHOD'] ) && 'OPTIONS' === $_SERVER['REQUEST_METHOD']; |
| 95 |
|
| 96 |
if ( $is_outbox_item && $is_preflight ) { |
| 97 |
/* |
| 98 |
* CORS preflight: override WordPress 404 so the browser |
| 99 |
* accepts the preflight response (must be 2xx). |
| 100 |
*/ |
| 101 |
\status_header( 200 ); |
| 102 |
} elseif ( $is_outbox_item ) { |
| 103 |
// Return 406 for non-ActivityPub requests to outbox items since they only support ActivityPub requests. |
| 104 |
\set_query_var( 'is_404', true ); |
| 105 |
\status_header( 406 ); |
| 106 |
} |
| 107 |
|
| 108 |
return $template; |
| 109 |
} |
| 110 |
|
| 111 |
$activitypub_object = Query::get_instance()->get_activitypub_object(); |
| 112 |
$queried_object = Query::get_instance()->get_queried_object(); |
| 113 |
|
| 114 |
/* |
| 115 |
* Serve the Tombstone for a deleted object — but not while an authorized |
| 116 |
* user is previewing it. During an editor `?preview=true` request, |
| 117 |
* `is_post_publicly_queryable()` treats a draft or pending post as |
| 118 |
* queryable only for a user who can edit it, so the author can still use |
| 119 |
* the Fediverse Preview on a post they just soft-deleted (which is |
| 120 |
* otherwise already in the tombstone registry). |
| 121 |
* |
| 122 |
* The bypass is scoped to that preview request on purpose. A normal |
| 123 |
* ActivityPub fetch (no `preview`) of a tombstoned URL always gets the |
| 124 |
* Tombstone — even if the URL now resolves to a fresh public post because |
| 125 |
* its slug was reused — since remote servers were told that id is gone. |
| 126 |
* The legitimate restore path clears the registry entry itself, via |
| 127 |
* `Create::maybe_unbury()` when the re-publish Create is queued. |
| 128 |
*/ |
| 129 |
$is_authorized_preview = \get_query_var( 'preview' ) |
| 130 |
&& $queried_object instanceof \WP_Post |
| 131 |
&& is_post_publicly_queryable( $queried_object ); |
| 132 |
|
| 133 |
if ( |
| 134 |
Tombstone::exists_local( Query::get_instance()->get_request_url() ) |
| 135 |
&& ! $is_authorized_preview |
| 136 |
) { |
| 137 |
// Set 410 Gone for permanently deleted posts, 200 OK for soft-deleted. |
| 138 |
if ( ! $activitypub_object ) { |
| 139 |
\status_header( 410 ); |
| 140 |
} |
| 141 |
|
| 142 |
return ACTIVITYPUB_PLUGIN_DIR . 'templates/tombstone-json.php'; |
| 143 |
} |
| 144 |
|
| 145 |
/* |
| 146 |
* Refuse to expose the content-negotiated representation of a post |
| 147 |
* that is no longer publicly queryable (non-public status, AP |
| 148 |
* visibility flipped, post-type support removed, etc.). The |
| 149 |
* lifecycle gate in `is_post_disabled()` intentionally lets such |
| 150 |
* posts through the federation pipeline so a Delete can fire, but |
| 151 |
* that escape hatch must not leak into front-end rendering during |
| 152 |
* the window between status change and Delete delivery. |
| 153 |
*/ |
| 154 |
if ( |
| 155 |
$activitypub_object && |
| 156 |
$queried_object instanceof \WP_Post && |
| 157 |
'ap_outbox' !== $queried_object->post_type && |
| 158 |
! is_post_publicly_queryable( $queried_object ) |
| 159 |
) { |
| 160 |
return $template; |
| 161 |
} |
| 162 |
|
| 163 |
$activitypub_template = false; |
| 164 |
|
| 165 |
if ( $activitypub_object ) { |
| 166 |
if ( \get_query_var( 'preview' ) ) { |
| 167 |
\defined( 'ACTIVITYPUB_PREVIEW' ) || \define( 'ACTIVITYPUB_PREVIEW', true ); |
| 168 |
|
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/* |
| 170 |
* A preview is only ever reached by someone allowed to see the unpublished post: |
| 171 |
* is_post_publicly_queryable() gates draft/pending/future on current_user_can('edit_post'), |
| 172 |
* and everyone else has already fallen through to the normal template above. The response |
| 173 |
* therefore varies by caller no matter the Authorized Fetch setting, so it must never be |
| 174 |
* stored by a shared cache and replayed to someone who cannot edit the post. Independent of |
| 175 |
* the Authorized Fetch block below, which only guards the signed-fetch path. |
| 176 |
*/ |
| 177 |
if ( ! \headers_sent() ) { |
| 178 |
\header( 'Cache-Control: private, no-store, max-age=0' ); |
| 179 |
} |
| 180 |
|
| 181 |
/** |
| 182 |
* Filter the template used for the ActivityPub preview. |
| 183 |
* |
| 184 |
* @param string $activitypub_template Absolute path to the template file. |
| 185 |
*/ |
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$activitypub_template = \apply_filters( 'activitypub_preview_template', ACTIVITYPUB_PLUGIN_DIR . '/templates/post-preview.php' ); |
| 187 |
} else { |
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$activitypub_template = ACTIVITYPUB_PLUGIN_DIR . 'templates/activitypub-json.php'; |
| 189 |
} |
| 190 |
} |
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|
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/* |
| 193 |
* Check if the request is authorized. |
| 194 |
* |
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* @see https://www.w3.org/wiki/SocialCG/ActivityPub/Primer/Authentication_Authorization#Authorized_fetch |
| 196 |
* @see https://swicg.github.io/activitypub-http-signature/#authorized-fetch |
| 197 |
*/ |
| 198 |
if ( $activitypub_template && use_authorized_fetch() ) { |
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/* |
| 200 |
* Under Authorized Fetch the response depends on the caller's signature: an unsigned request |
| 201 |
* is refused, a signed one gets the document. A shared cache (page cache or CDN) keys the |
| 202 |
* activity+json variant on the representation, not the signature, so it must store neither |
| 203 |
* outcome and replay it to the wrong caller. Send this before verifying so it covers the 401 |
| 204 |
* and the 200 alike; `max-age=0` is what page caches such as Surge key on to skip storing. |
| 205 |
*/ |
| 206 |
if ( ! \headers_sent() ) { |
| 207 |
\header( 'Cache-Control: private, no-store, max-age=0' ); |
| 208 |
} |
| 209 |
|
| 210 |
$verification = Signature::verify_http_signature( $_SERVER ); |
| 211 |
if ( \is_wp_error( $verification ) ) { |
| 212 |
\status_header( 401 ); |
| 213 |
|
| 214 |
// Fallback as template_loader can't return http headers. |
| 215 |
return $template; |
| 216 |
} |
| 217 |
} |
| 218 |
|
| 219 |
if ( $activitypub_template ) { |
| 220 |
\set_query_var( 'is_404', false ); |
| 221 |
|
| 222 |
// Check if header already sent. |
| 223 |
if ( ! \headers_sent() ) { |
| 224 |
// Send 200 status header. |
| 225 |
\status_header( 200 ); |
| 226 |
} |
| 227 |
|
| 228 |
return $activitypub_template; |
| 229 |
} |
| 230 |
|
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return $template; |
| 232 |
} |
| 233 |
|
| 234 |
/** |
| 235 |
* Add the 'self' link to the header. |
| 236 |
*/ |
| 237 |
public static function add_headers() { |
| 238 |
$id = Query::get_instance()->get_activitypub_object_id(); |
| 239 |
|
| 240 |
/* |
| 241 |
* Send CORS headers for resolved ActivityPub objects and outbox |
| 242 |
* items. Outbox items need CORS even when the object ID doesn't |
| 243 |
* resolve, because browser preflight requests don't carry the |
| 244 |
* Authorization header needed to authenticate private items. |
| 245 |
*/ |
| 246 |
$post_id = \get_query_var( 'p' ); |
| 247 |
$is_outbox_url = $post_id && Outbox::POST_TYPE === \get_post_type( $post_id ); |
| 248 |
|
| 249 |
if ( ! \headers_sent() && ( $id || $is_outbox_url ) ) { |
| 250 |
\header( 'Access-Control-Allow-Origin: *' ); |
| 251 |
\header( 'Access-Control-Allow-Methods: GET, OPTIONS' ); |
| 252 |
\header( 'Access-Control-Allow-Headers: Accept, Authorization, Content-Type' ); |
| 253 |
} |
| 254 |
|
| 255 |
if ( ! $id ) { |
| 256 |
return; |
| 257 |
} |
| 258 |
|
| 259 |
if ( ! \headers_sent() ) { |
| 260 |
\header( 'Link: <' . \esc_url( $id ) . '>; title="ActivityPub (JSON)"; rel="alternate"; type="application/activity+json"', false ); |
| 261 |
|
| 262 |
if ( \get_option( 'activitypub_vary_header', '1' ) ) { |
| 263 |
// Send Vary header for Accept header. |
| 264 |
\header( 'Vary: Accept', false ); |
| 265 |
} |
| 266 |
} |
| 267 |
|
| 268 |
\add_action( |
| 269 |
'wp_head', |
| 270 |
static function () use ( $id ) { |
| 271 |
echo PHP_EOL . '<link rel="alternate" title="ActivityPub (JSON)" type="application/activity+json" href="' . \esc_url( $id ) . '" />' . PHP_EOL; |
| 272 |
} |
| 273 |
); |
| 274 |
} |
| 275 |
|
| 276 |
/** |
| 277 |
* Remove trailing slash from ActivityPub @username requests. |
| 278 |
* |
| 279 |
* @param string $redirect_url The URL to redirect to. |
| 280 |
* @param string $requested_url The requested URL. |
| 281 |
* |
| 282 |
* @return string $redirect_url The possibly-unslashed redirect URL. |
| 283 |
*/ |
| 284 |
public static function no_trailing_redirect( $redirect_url, $requested_url ) { |
| 285 |
if ( \get_query_var( 'actor' ) ) { |
| 286 |
return $requested_url; |
| 287 |
} |
| 288 |
|
| 289 |
return $redirect_url; |
| 290 |
} |
| 291 |
|
| 292 |
/** |
| 293 |
* Add support for `p` and `author` query vars. |
| 294 |
* |
| 295 |
* @param string $redirect_url The URL to redirect to. |
| 296 |
* @param string $requested_url The requested URL. |
| 297 |
* |
| 298 |
* @return string $redirect_url |
| 299 |
*/ |
| 300 |
public static function redirect_canonical( $redirect_url, $requested_url ) { |
| 301 |
if ( ! is_activitypub_request() ) { |
| 302 |
return $redirect_url; |
| 303 |
} |
| 304 |
|
| 305 |
$query = \wp_parse_url( $requested_url, PHP_URL_QUERY ); |
| 306 |
|
| 307 |
if ( ! $query ) { |
| 308 |
return $redirect_url; |
| 309 |
} |
| 310 |
|
| 311 |
$query_params = \wp_parse_args( $query ); |
| 312 |
unset( $query_params['activitypub'] ); |
| 313 |
unset( $query_params['stamp'] ); |
| 314 |
|
| 315 |
if ( 1 !== \count( $query_params ) ) { |
| 316 |
return $redirect_url; |
| 317 |
} |
| 318 |
|
| 319 |
if ( isset( $query_params['p'] ) ) { |
| 320 |
return null; |
| 321 |
} |
| 322 |
|
| 323 |
if ( isset( $query_params['author'] ) ) { |
| 324 |
return null; |
| 325 |
} |
| 326 |
|
| 327 |
return $requested_url; |
| 328 |
} |
| 329 |
|
| 330 |
/** |
| 331 |
* Custom redirects for ActivityPub requests. |
| 332 |
* |
| 333 |
* @return void |
| 334 |
*/ |
| 335 |
public static function template_redirect() { |
| 336 |
global $wp_query; |
| 337 |
|
| 338 |
$comment_id = \get_query_var( 'c', null ); |
| 339 |
|
| 340 |
// Check if it seems to be a comment. |
| 341 |
if ( $comment_id ) { |
| 342 |
$comment = \get_comment( $comment_id ); |
| 343 |
|
| 344 |
// Load a 404-page if `c` is set but not valid. |
| 345 |
if ( ! $comment ) { |
| 346 |
$wp_query->set_404(); |
| 347 |
return; |
| 348 |
} |
| 349 |
|
| 350 |
// Stop if it's not an ActivityPub comment. |
| 351 |
if ( is_activitypub_request() && ! is_local_comment( $comment ) ) { |
| 352 |
return; |
| 353 |
} |
| 354 |
|
| 355 |
\wp_safe_redirect( \get_comment_link( $comment ) ); |
| 356 |
exit; |
| 357 |
} |
| 358 |
|
| 359 |
/* |
| 360 |
* Skip the actor branch when this looks like an actor-scoped FEP-7aa9 |
| 361 |
* stamp URL: numeric `actor` paired with a `stamp`. Those resolve to a |
| 362 |
* FeatureAuthorization via Activitypub\Query, not via the username |
| 363 |
* lookup which would 404 the numeric ID. Non-numeric actors fall |
| 364 |
* through to the regular Mastodon-style profile lookup. |
| 365 |
*/ |
| 366 |
$actor = \get_query_var( 'actor', null ); |
| 367 |
$is_stamp_url = $actor && \get_query_var( 'stamp' ) && \ctype_digit( (string) $actor ); |
| 368 |
if ( $actor && ! $is_stamp_url ) { |
| 369 |
$actor = Actors::get_by_username( $actor ); |
| 370 |
if ( ! $actor || \is_wp_error( $actor ) ) { |
| 371 |
$wp_query->set_404(); |
| 372 |
return; |
| 373 |
} |
| 374 |
|
| 375 |
if ( is_activitypub_request() ) { |
| 376 |
return; |
| 377 |
} |
| 378 |
|
| 379 |
\wp_safe_redirect( $actor->get_url(), 301 ); |
| 380 |
exit; |
| 381 |
} |
| 382 |
|
| 383 |
$term_id = \get_query_var( 'term_id', null ); |
| 384 |
if ( $term_id ) { |
| 385 |
$term = \get_term( $term_id ); |
| 386 |
|
| 387 |
// Load a 404-page if `term_id` is set but not valid. |
| 388 |
if ( ! $term || \is_wp_error( $term ) ) { |
| 389 |
$wp_query->set_404(); |
| 390 |
return; |
| 391 |
} |
| 392 |
|
| 393 |
/** |
| 394 |
* Filters the taxonomies supported for term redirects. |
| 395 |
* |
| 396 |
* @since 7.8.3 |
| 397 |
* |
| 398 |
* @param array $supported_taxonomies Array of taxonomy names. Default array( 'category', 'post_tag' ). |
| 399 |
*/ |
| 400 |
$supported_taxonomies = \apply_filters( 'activitypub_supported_taxonomies', array( 'category', 'post_tag' ) ); |
| 401 |
|
| 402 |
if ( ! \in_array( $term->taxonomy, $supported_taxonomies, true ) ) { |
| 403 |
return; |
| 404 |
} |
| 405 |
|
| 406 |
// Don't redirect for ActivityPub requests. |
| 407 |
if ( is_activitypub_request() ) { |
| 408 |
return; |
| 409 |
} |
| 410 |
|
| 411 |
$term_link = \get_term_link( $term ); |
| 412 |
if ( ! \is_wp_error( $term_link ) ) { |
| 413 |
\wp_safe_redirect( $term_link, 301 ); |
| 414 |
exit; |
| 415 |
} |
| 416 |
} |
| 417 |
} |
| 418 |
|
| 419 |
/** |
| 420 |
* Add the 'activitypub' query variable so WordPress won't mangle it. |
| 421 |
* |
| 422 |
* @param array $vars The query variables. |
| 423 |
* |
| 424 |
* @return array The query variables. |
| 425 |
*/ |
| 426 |
public static function add_query_vars( $vars ) { |
| 427 |
$vars[] = 'activitypub'; |
| 428 |
$vars[] = 'preview'; |
| 429 |
$vars[] = 'author'; |
| 430 |
$vars[] = 'actor'; |
| 431 |
$vars[] = 'stamp'; |
| 432 |
$vars[] = 'type'; |
| 433 |
$vars[] = 'c'; |
| 434 |
$vars[] = 'p'; |
| 435 |
$vars[] = 'term_id'; |
| 436 |
|
| 437 |
return $vars; |
| 438 |
} |
| 439 |
|
| 440 |
/** |
| 441 |
* Optimize home page query for ActivityPub requests. |
| 442 |
* |
| 443 |
* Skip the database query entirely for ActivityPub requests on the home page |
| 444 |
* since we only need to return the blog actor, not posts. |
| 445 |
* |
| 446 |
* @param \WP_Query $wp_query The WP_Query instance. |
| 447 |
*/ |
| 448 |
public static function fix_is_home_check( $wp_query ) { |
| 449 |
if ( |
| 450 |
$wp_query->get( 'actor' ) || |
| 451 |
$wp_query->get( 'stamp' ) || |
| 452 |
$wp_query->get( 'c' ) |
| 453 |
) { |
| 454 |
$wp_query->is_home = false; |
| 455 |
} |
| 456 |
} |
| 457 |
} |
| 458 |
|
