<?php
/**
* Parse a XRDS discovery description to a simple array format.
*
* For now a simple parse of the document. Better error checking
* in a later version.
*
* @version $Id$
* @author Marc Worrell <marcw@pobox.com>
*
*
* The MIT License
*
* Copyright (c) 2007-2008 Mediamatic Lab
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/* example of use:
header('content-type: text/plain');
$file = file_get_contents('../../test/discovery/xrds-magnolia.xrds');
$xrds = xrds_parse($file);
print_r($xrds);
*/
/**
* Parse the xrds file in the argument. The xrds description must have been
* fetched via curl or something else.
*
* TODO: more robust checking, support for more service documents
* TODO: support for URIs to definition instead of local xml:id
*
* @param string data contents of xrds file
* @exception Exception when the file is in an unknown format
* @return array
*/
function xrds_parse ( $data )
{
$oauth = array();
$doc = @DOMDocument::loadXML($data);
if ($doc === false)
{
throw new Exception('Error in XML, can\'t load XRDS document');
}
$xpath = new DOMXPath($doc);
$xpath->registerNamespace('xrds', 'xri://$xrds');
$xpath->registerNamespace('xrd', 'xri://$XRD*($v*2.0)');
$xpath->registerNamespace('simple', 'http://xrds-simple.net/core/1.0');
// Yahoo! uses this namespace, with lowercase xrd in it
$xpath->registerNamespace('xrd2', 'xri://$xrd*($v*2.0)');
$uris = xrds_oauth_service_uris($xpath);
foreach ($uris as $uri)
{
// TODO: support uris referring to service documents outside this one
if ($uri{0} == '#')
{
$id = substr($uri, 1);
$oauth = xrds_xrd_oauth($xpath, $id);
if (is_array($oauth) && !empty($oauth))
{
return $oauth;
}
}
}
return false;
}
/**
* Parse a XRD definition for OAuth and return the uris etc.
*
* @param XPath xpath
* @param string id
* @return array
*/
function xrds_xrd_oauth ( $xpath, $id )
{
$oauth = array();
$xrd = $xpath->query('//xrds:XRDS/xrd:XRD[@xml:id="'.$id.'"]');
if ($xrd->length == 0)
{
// Yahoo! uses another namespace
$xrd = $xpath->query('//xrds:XRDS/xrd2:XRD[@xml:id="'.$id.'"]');
}
if ($xrd->length >= 1)
{
$x = $xrd->item(0);
$services = array();
foreach ($x->childNodes as $n)
{
switch ($n->nodeName)
{
case 'Type':
if ($n->nodeValue != 'xri://$xrds*simple')
{
// Not a simple XRDS document
return false;
}
break;
case 'Expires':
$oauth['expires'] = $n->nodeValue;
break;
case 'Service':
list($type,$service) = xrds_xrd_oauth_service($n);
if ($type)
{
$services[$type][xrds_priority($n)][] = $service;
}
break;
}
}
// Flatten the services on priority
foreach ($services as $type => $service)
{
$oauth[$type] = xrds_priority_flatten($service);
}
}
else
{
$oauth = false;
}
return $oauth;
}
/**
* Parse a service definition for OAuth in a simple xrd element
*
* @param DOMElement n
* @return array (type, service desc)
*/
function xrds_xrd_oauth_service ( $n )
{
$service = array(
'uri' => '',
'signature_method' => array(),
'parameters' => array()
);
$type = false;
foreach ($n->childNodes as $c)
{
$name = $c->nodeName;
$value = $c->nodeValue;
if ($name == 'URI')
{
$service['uri'] = $value;
}
else if ($name == 'Type')
{
if (strncmp($value, 'http://oauth.net/core/1.0/endpoint/', 35) == 0)
{
$type = basename($value);
}
else if (strncmp($value, 'http://oauth.net/core/1.0/signature/', 36) == 0)
{
$service['signature_method'][] = basename($value);
}
else if (strncmp($value, 'http://oauth.net/core/1.0/parameters/', 37) == 0)
{
$service['parameters'][] = basename($value);
}
else if (strncmp($value, 'http://oauth.net/discovery/1.0/consumer-identity/', 49) == 0)
{
$type = 'consumer_identity';
$service['method'] = basename($value);
unset($service['signature_method']);
unset($service['parameters']);
}
else
{
$service['unknown'][] = $value;
}
}
else if ($name == 'LocalID')
{
$service['consumer_key'] = $value;
}
else if ($name{0} != '#')
{
$service[strtolower($name)] = $value;
}
}
return array($type, $service);
}
/**
* Return the OAuth service uris in order of the priority.
*
* @param XPath xpath
* @return array
*/
function xrds_oauth_service_uris ( $xpath )
{
$uris = array();
$xrd_oauth = $xpath->query('//xrds:XRDS/xrd:XRD/xrd:Service/xrd:Type[.=\'http://oauth.net/discovery/1.0\']');
if ($xrd_oauth->length > 0)
{
$service = array();
foreach ($xrd_oauth as $xo)
{
// Find the URI of the service definition
$cs = $xo->parentNode->childNodes;
foreach ($cs as $c)
{
if ($c->nodeName == 'URI')
{
$prio = xrds_priority($xo);
$service[$prio][] = $c->nodeValue;
}
}
}
$uris = xrds_priority_flatten($service);
}
return $uris;
}
/**
* Flatten an array according to the priority
*
* @param array ps buckets per prio
* @return array one dimensional array
*/
function xrds_priority_flatten ( $ps )
{
$prio = array();
$null = array();
ksort($ps);
foreach ($ps as $idx => $bucket)
{
if (!empty($bucket))
{
if ($idx == 'null')
{
$null = $bucket;
}
else
{
$prio = array_merge($prio, $bucket);
}
}
}
$prio = array_merge($prio, $bucket);
return $prio;
}
/**
* Fetch the priority of a element
*
* @param DOMElement elt
* @return mixed 'null' or int
*/
function xrds_priority ( $elt )
{
if ($elt->hasAttribute('priority'))
{
$prio = $elt->getAttribute('priority');
if (is_numeric($prio))
{
$prio = intval($prio);
}
}
else
{
$prio = 'null';
}
return $prio;
}
/* vi:set ts=4 sts=4 sw=4 binary noeol: */
?> |