Question

I’m having issues with following a redirect while maintaining session cookie and post field information. This is how the process goes:

1) Visit URL, they return a cookie and a 302 response (pointing to the same URL you just visited)

2) Re-Visit URL with the cookie they gave you and you can see the proper page.

I can get through to the proper page with CURLOPT_FOLLOWLOCATION = true, however I guess CURL doesn’t keep the post fields when following a redirect, so there is no useful content on the page.

I have tried manually storing the cookie, and performing the ‘redirect’ myself with the stored cookie, however with this method I never get past the 302 redirect to the proper page. The code for the manual method mentioned here is below.

$tmp_name = tempnam('tmp', 'COOKIE');
$url = "MY_URL";

$options = array(
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_REFERER => $url,
    CURLOPT_HEADER => true,
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => array(
        'field1' => 'postfield1',
        'field2' => 'postfield2',
    ),
    CURLOPT_VERBOSE => true,
);

// Make the first request, specifying where to store the cookie
// This request returns the cookie and the 302 response
$ch = curl_init($url);
curl_setopt_array($ch, $options);
curl_setopt($ch, CURLOPT_COOKIEJAR, $tmp_name);
$resp1 = curl_exec($ch);

// Make the second request, using the cookie stored above
// Should return the proper page, but gives me the 302 again instead.
$ch = curl_init($url);
curl_setopt_array($ch, $options);
curl_setopt($ch, CURLOPT_COOKIEFILE, $tmp_name);
$resp2 = curl_exec($ch);

Does anyone know what’s wrong with the above code, or if there’s another way to accomplish the task?

Answer 1

First of all, post data is never kept on redirect. So don’t worry about that, you don’t have to make two requests. Just stick with

curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);

I would also suggest the following for further debuging: even if you make two requests, use same curl resource, don’t close it to make new one. Also, add:

curl_setopt($ch, CURLOPT_FORBID_REUSE, 0);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, 0);
curl_setopt($ch, CURLOPT_AUTOREFERER, 1);
curl_setopt($ch, CURLOPT_USERAGENT, "valid user agent");

You could also use browser addons (i.e. HttpFox) to check the exact cookies and requests sequence that are needed. You are trying to emulate real request, so looking in-depth at one that your browser makes can help a lot.