streams/Zotlabs/Module/Webfinger.php

<?php
namespace Zotlabs\Module;

use Zotlabs\Web\Controller;
use App;

class Webfinger extends Controller {

	function init() {

		logger('webfinger from ' . $_SERVER['REMOTE_ADDR']);

		// This is a public resource with relaxed CORS policy. Close the current login session.
		session_write_close();
		
		header('Access-Control-Allow-Origin: *');

		$result = [];
		
		if (! is_https_request()) {
			header($_SERVER['SERVER_PROTOCOL'] . ' ' . 500 . ' ' . 'Webfinger requires HTTPS');
			killme();
		}
	
		$resource = $_REQUEST['resource'];

		if (! $resource) {
			http_status_exit(404,'Not found');
		}

		logger('webfinger: ' . $resource, LOGGER_DEBUG);
	
		// Response for a site resource

		if (strcasecmp(rtrim($resource,'/'),z_root()) === 0) {
			$result['subject'] = $resource;
			$result['properties'] = [
					'https://w3id.org/security/v1#publicKeyPem' => get_config('system','pubkey')
			];
			$result['links'] = [
				[
					'rel'  => 'http://purl.org/openwebauth/v1',
					'type' => 'application/x-zot+json',
					'href' => z_root() . '/owa',
				],
			
				[ 
					'rel'  => 'http://purl.org/zot/protocol/6.0', 
					'type' => 'application/x-zot+json', 
					'href' => z_root(),
				],

			];
		}
		else {

			// some other resource

			if (strpos($resource,'tag:' === 0)) {
				$arr = explode(':',$resource);
				if (count($arr) > 3 && $arr[2] === 'zotid') {
					$hash = $arr[3];
					$channel_target = channelx_by_hash($hash);
				}
			}
 
			if (strpos($resource,'acct:') === 0) {
				$channel_nickname = punify(str_replace('acct:','',$resource));
				if (strrpos($channel_nickname,'@') !== false) {
					$host = punify(substr($channel_nickname,strrpos($channel_nickname,'@')+1));

					// If the webfinger address points off site, redirect to the correct site

					if (strcasecmp($host, App::get_hostname())) {
						goaway('https://' . $host . '/.well-known/webfinger?f=&resource=' . $resource);
					}
					$channel_nickname = substr($channel_nickname,0,strrpos($channel_nickname,'@'));
				}		
			}
			if (strpos($resource,'http') === 0) {
				$channel_nickname = str_replace('~','',basename($resource));
			}

			if ($channel_nickname) {	
				$channel_target = channelx_by_nick($channel_nickname);
			}
		}

		if ($channel_target) {
	
			$h = get_hubloc_addrs_by_hash($channel_target['channel_hash']);
	
			$result['subject'] = $resource;
	
			$aliases = [
				z_root() . '/channel/' . $channel_target['channel_address'],
				z_root() . '/~' . $channel_target['channel_address'],
				z_root() . '/@' . $channel_target['channel_address']

			];
	
			if ($h) {
				foreach ($h as $hh) {
					$aliases[] = 'acct:' . $hh['hubloc_addr'];
				}
			}
	
			$result['aliases'] = [];
	
			$result['properties'] = [
				'http://webfinger.net/ns/name'   => $channel_target['channel_name'],
				'http://xmlns.com/foaf/0.1/name' => $channel_target['channel_name'],
				'https://w3id.org/security/v1#publicKeyPem' => $channel_target['xchan_pubkey'],
				'http://purl.org/zot/federation' => ((get_config('system','activitypub',true)) ? 'zot6,activitypub' : 'zot6')
			];
	
			foreach ($aliases as $alias) { 
				if ($alias != $resource) {
					$result['aliases'][] = $alias;
				}
			}
	
			$result['links'] = [

				[
					'rel'  => 'http://webfinger.net/rel/avatar',
					'type' => $channel_target['xchan_photo_mimetype'],
					'href' => $channel_target['xchan_photo_l']	
				],

				[
					'rel'  => 'http://webfinger.net/rel/blog',
					'href' => z_root() . '/channel/' . $channel_target['channel_address'],
				],
	
				[
					'rel'  => 'http://openid.net/specs/connect/1.0/issuer',
					'href' => z_root()
				],

				[ 
					'rel'  => 'http://purl.org/zot/protocol/6.0', 
					'type' => 'application/x-zot+json', 
					'href' => z_root() . '/channel/' . $channel_target['channel_address'],
				],

				[
					'rel'  => 'http://purl.org/openwebauth/v1',
					'type' => 'application/x-zot+json',
					'href' => z_root() . '/owa'
				],

				[
					'rel'  => 'self',
					'type' => 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
					'href' => z_root() . '/channel/' . $channel_target['channel_address']
    			],
				
				[
					'rel'  => 'self',
					'type' => 'application/activity+json',
					'href' => z_root() . '/channel/' . $channel_target['channel_address']
    			],

				[ 
					'rel' => 'http://ostatus.org/schema/1.0/subscribe',
					'template' => z_root() . '/follow?url={uri}'
				],
			];
		}

		if (! $result) {
			header($_SERVER['SERVER_PROTOCOL'] . ' ' . 400 . ' ' . 'Bad Request');
			killme();
		}
	
		$arr = [ 'channel' => $channel_target, 'request' => $_REQUEST, 'result' => $result ];
		call_hooks('webfinger',$arr);


		json_return_and_die($arr['result'],'application/jrd+json');
	}
}