Add/User Delete activities

includes/class-activity-dispatcher.php

@@ -7,7 +7,6 @@
 use Activitypub\Collection\Users;
 use Activitypub\Collection\Followers;
 use Activitypub\Transformer\Factory;
-use Activitypub\Transformer\Post;
 use Activitypub\Transformer\Comment;
 
 use function Activitypub\is_single_user;
@@ -33,6 +32,7 @@ public static function init() {
 		\add_action( 'activitypub_send_activity', array( self::class, 'send_activity' ), 10, 2 );
 		\add_action( 'activitypub_send_activity', array( self::class, 'send_activity_or_announce' ), 10, 2 );
 		\add_action( 'activitypub_send_update_profile_activity', array( self::class, 'send_profile_update' ), 10, 1 );
+		\add_action( 'activitypub_send_actor_delete_activity', array( self::class, 'send_actor_delete_activity' ), 10, 2 );
 	}
 
 	/**
@@ -174,8 +174,26 @@ private static function send_activity_to_followers( $activity, $user_id, $wp_obj
 		foreach ( $inboxes as $inbox ) {
 			safe_remote_post( $inbox, $json, $user_id );
 		}
+	}
 
-		set_wp_object_state( $wp_object, 'federated' );
+	/**
+	 * Send an Activity to all known (shared_)inboxes.
+	 *
+	 * @param Activity $activity The ActivityPub Activity.
+	 *
+	 * @return void
+	 */
+	public static function send_actor_delete_activity( $activity, $user_id = Users::APPLICATION_USER_ID ) {
+		$json = $activity->to_json();
+		$followers = Followers::get_all_followers();
+		$known_inboxes = [];
+		foreach ( $followers as $follower ) {
+			$known_inboxes[] = $follower->get_shared_inbox();
+		}
+		$inboxes = array_unique( $known_inboxes );
+		foreach ( $inboxes as $inbox ) {
+			safe_remote_post( $inbox, $json, $user_id );
+		}
 	}
 
 	/**

includes/class-scheduler.php

@@ -5,9 +5,11 @@
 use Activitypub\Transformer\Post;
 use Activitypub\Collection\Users;
 use Activitypub\Collection\Followers;
+use Activitypub\Activity\Activity;
 
-use function Activitypub\was_comment_sent;
+use function Activitypub\get_private_key_for;
 use function Activitypub\is_user_type_disabled;
+use function Activitypub\was_comment_sent;
 use function Activitypub\should_comment_be_federated;
 use function Activitypub\get_remote_metadata_by_actor;
 
@@ -75,6 +77,7 @@ function ( $comment_id ) {
 
 		// profile updates for user options
 		if ( ! is_user_type_disabled( 'user' ) ) {
+			\add_action( 'delete_user', array( self::class, 'schedule_actor_delete' ), 10, 3 );
 			\add_action( 'wp_update_user', array( self::class, 'user_update' ) );
 			\add_action( 'updated_user_meta', array( self::class, 'user_meta_update' ), 10, 3 );
 			// @todo figure out a feasible way of updating the header image since it's not unique to any user.
@@ -330,4 +333,31 @@ public static function schedule_profile_update( $user_id ) {
 			array( $user_id )
 		);
 	}
+
+	/**
+	 * Send an Actor Delete activity.
+	 * @param int $user_id  The user ID to Delete.
+	 */
+	public static function schedule_actor_delete( $user_id ) {
+		$user = get_userdata( $user_id );
+		if ( $user->has_cap( 'activitypub' ) ) {
+			$author_url = \get_author_posts_url( $user->ID );
+			add_option(
+				'activitypub_temp_sig_' . $user_id,
+				array(
+					'key_id' => $author_url . '#main-key',
+					'private_key' => Signature::get_private_key_for( $user_id ),
+				)
+			);
+
+			$activity = new Activity();
+			$activity->set_id( $author_url . '#delete' );
+			$activity->set_type( 'Delete' );
+			$activity->set_actor( $author_url );
+			$activity->set_object( $author_url );
+			$activity->set_to( [ 'https://www.w3.org/ns/activitystreams#Public' ] );
+
+			\wp_schedule_single_event( \time(), 'activitypub_send_actor_delete_activity', array( $activity, $user_id ) );
+		}
+	}
 }

includes/class-signature.php

@@ -186,7 +186,14 @@ protected static function check_legacy_key_pair_for( $user_id ) {
 	 */
 	public static function generate_signature( $user_id, $http_method, $url, $date, $digest = null ) {
 		$user = Users::get_by_id( $user_id );
-		$key  = self::get_private_key_for( $user->get__id() );
+		if ( ! is_wp_error( $user ) ) {
+			$key = self::get_private_key_for( $user->get__id() );
+			$key_id = $user->get_url() . '#main-key';
+		} else {
+			$temp_sig_options = get_option( 'activitypub_temp_sig_' . $user_id );
+			$key = $temp_sig_options['private_key'];
+			$key_id = $temp_sig_options['key_id'];
+		}
 
 		$url_parts = \wp_parse_url( $url );
 
@@ -215,8 +222,6 @@ public static function generate_signature( $user_id, $http_method, $url, $date,
 		\openssl_sign( $signed_string, $signature, $key, \OPENSSL_ALGO_SHA256 );
 		$signature = \base64_encode( $signature ); // phpcs:ignore
 
-		$key_id = $user->get_url() . '#main-key';
-
 		if ( ! empty( $digest ) ) {
 			return \sprintf( 'keyId="%s",algorithm="rsa-sha256",headers="(request-target) host date digest",signature="%s"', $key_id, $signature );
 		} else {