WebFinger client library for PHP.
Discover meta data about users by just their email address. Discoverable data may be the user's OpenID, profile page URL, link to portable contacts, hcard, foaf and other user pages.
Distributed social networks use WebFinger to distribute public encryption keys, OStatus and Salmon URLs.
Package supports Webfinger (RFC 7033) and can fall back to RFC 6415 (host-meta + lrdd).
Contents
The package does not throw any exceptions.
Technically, Net_WebFinger_Error
objects are exceptions, but they are
only set as $error
property in the Net_WebFinger_Reaction
object.
You can ignore them completely if you're just out to get the data.
Sometimes it's even necessary to ignore the data.
Yahoo! for example has a host-meta
file, but no LRDD files.
The OpenID provider URL already noted in host-meta
, so even though
fetching the LRDD file fails, information about the OpenID provider is available.
The Net_WebFinger_Reaction
object has an $error
property that contains
an exception with error message and code.
It often even has a previous exception object with more underlying details:
<?php require_once 'Net/WebFinger.php'; $wf = new Net_WebFinger(); $react = $wf->finger('user@example.org'); if ($react->error !== null) { echo "Error when fetching " . $react->url . "\n"; echo "Error: " . $react->error->getMessage() . "\n"; if ($react->error->getPrevious()) { echo "Underlying error: " . $react->error->getPrevious()->getMessage() . "\n"; } } ?>
<?php require_once 'Net/WebFinger.php'; $wf = new Net_WebFinger(); $react = $wf->finger('user@example.org'); if ($react->error) { echo 'There was an error: ' . $react->error->getMessage() . "\n"; } $openIdProvider = $react->get('http://specs.openid.net/auth/2.0/provider'); if ($openIdProvider !== null) { echo 'OpenID provider found: ' . $openIdProvider . "\n"; } ?>
Some common link relations have a short name in Net_WebFinger
.
Those short names can be used to access them more easily:
<?php require_once 'Net/WebFinger.php'; $wf = new Net_WebFinger(); $react = $wf->finger('user@example.org'); if ($react->error) { echo 'There was an error: ' . $react->error->getMessage() . "\n"; } if ($react->openid !== null) { echo 'OpenID provider found: ' . $react->openid . "\n"; } ?>
Currently supported short names:
contacts
hcard
openid
profile
xfn
See the list $shortNameMap
in class Net_WebFinger_Reaction
.
You can use foreach
on the reaction object to get all links:
<?php require_once 'Net/WebFinger.php'; $wf = new Net_WebFinger(); $react = $wf->finger('user@example.org'); foreach ($react as $link) { echo 'Link: ' . $link->rel . ' to ' . $link->href . "\n"; } ?>
With caching, the retrieved files will be stored locally which leads to faster lookup times when the same identifier (email address) is loaded again, and when another identifier on the same host is retrieved.
<?php require_once 'Net/WebFinger.php'; require_once 'Cache.php'; $wf = new Net_WebFinger(); $wf->setCache( new Cache('file', array('cache_dir' => sys_get_temp_dir() . '/myapp')) ); $react = $wf->finger('user@example.org'); $openIdProvider = $react->get('http://specs.openid.net/auth/2.0/provider'); ?>
Note: PEAR's Cache_Lite package does not support per-item lifetimes, so we cannot use it: http://pear.php.net/bugs/bug.php?id=13297
All files will be retrieved via SSL when possible, with fallback to normal HTTP.
The fallback for pure webfinger files does only happen when $fallbackToHttp
is enabled.
Fallback for host-meta
and LRDD files is always on.
The XRD subject is also verified. When it does not match the host name of the email address, then the error object is set.
<?php require_once 'Net/WebFinger.php'; $wf = new Net_WebFinger(); $react = $wf->finger('user@example.org'); if ($react->error || !$react->secure) { die("Those data may not be trusted\n"); }
If you want to send special HTTP headers or need e.g. proxy settings, you may use an own HTTP adapter that's used to fetch the files:
<?php require_once 'HTTP/Request2.php'; require_once 'Net/WebFinger.php'; $req = new HTTP_Request2(); $req->setConfig('follow_redirects', true);//needed for full compatibility $req->setHeader('User-Agent', 'MyApp 1.42'); $wf = new Net_WebFinger(); $wf->setHttpClient($req); $react = $wf->finger('foo@example.org');
You can use this identifiers to test the WebFinger functionality on various providers:
- Gmail: evalpaul@gmail.com
- Yahoo: mcorne@yahoo.com
- AOL: M4dSquirrels@aol.com
- other:
- diaspora: kevinkleinman@joindiaspora.com
- status.net: singpolyma@identi.ca
- Webfinger mailing list
- First webfinger specification
- Common link relations
- IETF webfinger draft
- http://hueniverse.com/2009/09/implementing-webfinger/
- http://hueniverse.com/2009/09/openid-and-lrdd/
- http://paulosman.me/2010/02/01/google-webfinger.html Google have since rolled out WebFinger support for everyone with a Google Profile.
- Finger history
- XRD 1.0 specification
See http://www.packetizer.com/webfinger/software.html
- Ruby:
- Perl: WWW::Finger::Webfinger
- PHP: discovery-php
- PHP Wordpress plugin: Blogpost, webfinger-profile plugin