Curl Replacement on GAE for BaseFacebook class - php

Question

I am wanting to implement federated logins to my GAE app in PHP.
I have looked at a couple of third parties like janrain or the OAuth plugin, but I just can't integrate them very easily and I don't want to pay or have limits. I just want something simple that will hook into the GAE authentication model.
At the moment I have google and yahoo as they are the only 2 that use an endpoint that doesn't require a username, and I can use the UserService::createLoginUrl()
I want to add Facebook, Twitter and Microsoft, plus others I guess, but these are my aim for now.
I started with facebook I am trying to use the facebook connector. Initially I started with the Javascript API and it worked well until you sit behind a firewall and facebook is blocked (then $.getScript() fails unmanageably), so I then started looking at the PHP library (at least then the blocking is a) visible to the user, b) not my responsibility for trapping and handling and c) fits nicely into the URL endpoint model I have)
The problem is that the BaseFacebook class uses cURL. GAE does not.
Does anyone know of a way to build the authentication into GAE so I can use login: required or if not, can anyone with better streams/curl knowlege than me replace the cURL stuff in the BaseFacebook class. Here is the function that's causing my grief:
/**
* Makes an HTTP request. This method can be overridden by subclasses if
* developers want to do fancier things or use something other than curl to
* make the request.
*
* #param string $url The URL to make the request to
* #param array $params The parameters to use for the POST body
* #param CurlHandler $ch Initialized curl handle
*
* #return string The response text
*/
protected function makeRequest($url, $params, $ch=null) {
if (!$ch) {
$ch = curl_init();
}
$opts = self::$CURL_OPTS;
if ($this->getFileUploadSupport()) {
$opts[CURLOPT_POSTFIELDS] = $params;
} else {
$opts[CURLOPT_POSTFIELDS] = http_build_query($params, null, '&');
}
$opts[CURLOPT_URL] = $url;
// disable the 'Expect: 100-continue' behaviour. This causes CURL to wait
// for 2 seconds if the server does not support this header.
if (isset($opts[CURLOPT_HTTPHEADER])) {
$existing_headers = $opts[CURLOPT_HTTPHEADER];
$existing_headers[] = 'Expect:';
$opts[CURLOPT_HTTPHEADER] = $existing_headers;
} else {
$opts[CURLOPT_HTTPHEADER] = array('Expect:');
}
curl_setopt_array($ch, $opts);
$result = curl_exec($ch);
$errno = curl_errno($ch);
// CURLE_SSL_CACERT || CURLE_SSL_CACERT_BADFILE
if ($errno == 60 || $errno == 77) {
self::errorLog('Invalid or no certificate authority found, '.
'using bundled information');
curl_setopt($ch, CURLOPT_CAINFO,
dirname(__FILE__) . DIRECTORY_SEPARATOR . 'fb_ca_chain_bundle.crt');
$result = curl_exec($ch);
}
// With dual stacked DNS responses, it's possible for a server to
// have IPv6 enabled but not have IPv6 connectivity. If this is
// the case, curl will try IPv4 first and if that fails, then it will
// fall back to IPv6 and the error EHOSTUNREACH is returned by the
// operating system.
if ($result === false && empty($opts[CURLOPT_IPRESOLVE])) {
$matches = array();
$regex = '/Failed to connect to ([^:].*): Network is unreachable/';
if (preg_match($regex, curl_error($ch), $matches)) {
if (strlen(#inet_pton($matches[1])) === 16) {
self::errorLog('Invalid IPv6 configuration on server, '.
'Please disable or get native IPv6 on your server.');
self::$CURL_OPTS[CURLOPT_IPRESOLVE] = CURL_IPRESOLVE_V4;
curl_setopt($ch, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
$result = curl_exec($ch);
}
}
}
if ($result === false) {
$e = new FacebookApiException(array(
'error_code' => curl_errno($ch),
'error' => array(
'message' => curl_error($ch),
'type' => 'CurlException',
),
));
curl_close($ch);
throw $e;
}
curl_close($ch);
return $result;
}

Answer 1

login: required in Google App Engine is not extensible by your application. If you wish to offer login from multiple providers you will need to turn that off in your app.yaml and instead handle the authentication within your application - which it sounds like you're working on.
You might want to look at using the Google Identity Toolkit - it offers login for some of the providers you list (more than just Google) and has PHP examples:
https://developers.google.com/identity-toolkit/