Need help logging to remote site with PHP using cURL - php

Question

I am trying to log into the following site remotely using cURL but I am having trouble.
http://www.cbssports.com/login
Does anyone know what I am doing wrong? Thank you.
<?
$url = 'http://www.cbssports.com/login';
$fields = array(
'login_form::userid'=>urlencode('USERNAME'),
'login_form::password'=>urlencode('PASSWORD')
);
foreach($fields as $key=>$value) { $fields_string .= $key.'='.$value.'&'; }
$fields_string = rtrim($fields_string,'&');
$ch = curl_init();
curl_setopt($ch,CURLOPT_URL,$url);
curl_setopt($ch,CURLOPT_POST,count($fields));
curl_setopt($ch,CURLOPT_POSTFIELDS,$fields_string);
curl_setopt ($ch,CURLOPT_RETURNTRANSFER, 1);
$result = curl_exec($ch);
curl_close($ch);
?>

Answer 1

The from has a lot of hidden fields, there's a good change that one or all of these are required (see trimmed version of the form below).
<form method="post" action="/login/index" name="login_form" id="login_form" >
<input type="hidden" name="dummy::login_form" id="dummy::login_form" value="1">
<input type="hidden" id="form::login_form" name="form::login_form" value="login_form">
<input type="hidden" value="http://www.cbssports.com/login" name="login_form::xurl" id="xurl">
<input type="hidden" value="150" name="login_form::master_product" id="master_product">
<input type="hidden" value="cbssports" name="login_form::vendor" id="vendor">
<input type="text" value="" name="login_form::userid" id="userid" size="30" maxlength="50" data-field-required="1">
<input type="password" value="" name="login_form::password" id="password" size="30" maxlength="12" data-field-required="1">
<input type="submit" value="Sign In" class="formButton">
</form>

Answer 2

If you're using Firefox, I recommend you do a dummy post using LiveHTTPHeaders, just to check all the post fields.

Answer 3

I know this is old, but I was fiddling with the same thing using .NET. Here is what the content string will look like in the POST request (using C# string concatenation):
"dummy%3A%3Alogin_form=1&form%3A%3Alogin_form=login_form&login_form%3A%3Axurl=http%3A%2F%2Fwww.cbssports.com%2Flogin&login_form%3A%3Amaster_product=150&login_form%3A%3Avendor=cbssports&login_form%3A%3Auserid=" + userID + "&login_form%3A%3Apassword=" + password
Notice that the miscellaneous hidden fields will also need to be in there. The additional catch I ran into was that the response has more than one cookie that you'll need for the subsequent GET request. Thus, you'd need to use some kind of container rather than appending a single "Set-cookie" header. That will not work and your output stream will simply return the data from the main page you're redirected to.
Hope that helps someone.