501 HTTP error when trying to use php OpenID with Google - php

Question

I've been trying to implement openID authentication as a consumer in a project I'm developing, and I haven't yet managed to make even the examples work as I want.
Even though the example consumer works perfectly for yahoo openid authentication, it fails in the try_auth.php page with a 501 HTTP error when trying to use google openID.
Here's the code for try_auth.php (the page that handles the call to the actual openID provider):
<?php
error_reporting(E_ALL);
ini_set('display_errors','On');
require_once "common.php";
session_start();
function getOpenIDURL() {
// Render a default page if we got a submission without an openid
// value.
if (empty($_GET['openid_identifier'])) {
$error = "Expected an OpenID URL.";
include 'index.php';
exit(0);
}
return $_GET['openid_identifier'];
}
function run() {
$openid = getOpenIDURL();
$consumer = getConsumer();
// Begin the OpenID authentication process.
$auth_request = $consumer->begin($openid);
// No auth request means we can't begin OpenID.
if (!$auth_request) {
displayError("Authentication error; not a valid OpenID.");
}
$sreg_request = Auth_OpenID_SRegRequest::build(
// Required
array('nickname'),
// Optional
array('fullname', 'email'));
if ($sreg_request) {
$auth_request->addExtension($sreg_request);
}
$policy_uris = null;
if (isset($_GET['policies'])) {
$policy_uris = $_GET['policies'];
}
$pape_request = new Auth_OpenID_PAPE_Request($policy_uris);
if ($pape_request) {
$auth_request->addExtension($pape_request);
}
// Redirect the user to the OpenID server for authentication.
// Store the token for this authentication so we can verify the
// response.
// For OpenID 1, send a redirect. For OpenID 2, use a Javascript
// form to send a POST request to the server.
if ($auth_request->shouldSendRedirect()) {
$redirect_url = $auth_request->redirectURL(getTrustRoot(),
getReturnTo());
// If the redirect URL can't be built, display an error
// message.
if (Auth_OpenID::isFailure($redirect_url)) {
displayError("Could not redirect to server: " . $redirect_url->message);
} else {
// Send redirect.
header("Location: ".$redirect_url);
}
} else {
// Generate form markup and render it.
$form_id = 'openid_message';
$form_html = $auth_request->htmlMarkup(getTrustRoot(), getReturnTo(),
false, array('id' => $form_id));
// Display an error if the form markup couldn't be generated;
// otherwise, render the HTML.
if (Auth_OpenID::isFailure($form_html)) {
displayError("Could not redirect to server: " . $form_html->message);
} else {
print $form_html;
}
}
}
run();
?>
Another think I noticed is that on my windows dev box (Apache 2.2.6 standalone, not XAMPP, PHP 5.3.8) everything runs smoothly, both yahoo and Google perform openID authentication without any issues.
Anyone have an idea what might be wrong?
Thanks in advance.

Answer 1

After some trial and error, I came to the conclusion that the 501 error occurs due to the Google openID url being passed to the page either as querystring (for form method "get") either as postdata (for form method "post"). In particular, the url I was using is
https://www.google.com/accounts/o8/id
the last part (the "id") is triggering the 501 error. If I use
https://www.google.com/accounts/o8/id/
the error is not triggered. Well, since the two are equivalent urls, I'll be using the second one. I'm still curious as to why this was happening though.