Automating Linkedin oAuth usin Curl and PHP - php

Question

I am trying to automate the process of authenticating LinkedIn login in order to perform a public search for people on LinkedIn.
First i will try to explain what i was doing.
I am using four files:
oAuth.php (required)
linkedin.php (php LinkedIn library)
auth.php (which gets oAuth token from the LinkedIn lib file)
callback url demo.php?params (which, after successful authenticaton, prints the current user's profile and the search results using params)
The authentication url is https://api.linkedin.com/uas/oauth/authorize?oauth_token=$oauthtoken.
I did two things, neither seems to work; they are:
I am using curl to automate the process of going to the authentication url, posting fields (username, password, oauth token, csrfToken, duration, sourceAlias, etc., which I came to know from Firebug).
The only two things which change here are oauth token and csrfToken (by parsing the content in the authentication url). I was able to get both, each time the page loads, and finally trying to print the GET response from curl_exec.
Trying to post just the email and password, and trying to print a GET response.
For reference here is my auth.php:
function extract_unit($string, $start, $end)
{
$pos = stripos($string, $start);
$str = substr($string, $pos);
$str_two = substr($str, strlen($start));
$second_pos = stripos($str_two, $end);
$str_three = substr($str_two, 0, $second_pos);
$unit = trim($str_three); // remove whitespaces
return $unit;
}
session_start();
$config['base_url'] = 'http://linkedin.tweetrank.tk/auth.php';
$config['callback_url'] = 'http://linkedin.tweetrank.tk/demo.php';
$config['linkedin_access'] = 'my key';
$config['linkedin_secret'] = 'my secret';
include_once "linkedin.php";
# First step is to initialize with the consumer key and secret. We'll use
# an out-of-band oauth_callback
$linkedin = new LinkedIn($config['linkedin_access'], $config['linkedin_secret'], $config['callback_url']);
//$linkedin->debug = true;
# Now we retrieve a request token. It will be set as $linkedin->request_token
$linkedin->getRequestToken();
$_SESSION['requestToken'] = serialize($linkedin->request_token);
# With a request token in hand, we can generate an authorization URL, which
# we'll direct the user to
//echo "Authorization URL: " . $linkedin->generateAuthorizeUrl() . "\n\n";
echo $url = $linkedin->generateAuthorizeUrl();
$token = $linkedin->generateAuthorizeToken();
//echo '<br><br>';
$data = file_get_contents($url);
$csrfToken = extract_unit($data,'name="csrfToken" value="','"');
//echo $csrfToken;
//echo $token;
//echo 'https://www.linkedin.com/uas/oauth/authenticate?oauth_token='.$token.'&trk=uas-continue';
// INIT CURL
$postParams = 'email=myemail&password=mypassword&duration=720&authorize=Ok%2C+I%27ll+Allow+It&extra=&access=-3&agree=true&oauth_token='.$token.'&appId=&csrfToken='.$csrfToken.'&sourceAlias=0_8L1usXMS_e_-SfuxXa1idxJ207ESR8hAXKfus4aDeAk';
Now I used the authentication URL and the postParams with curl.

Answer 1

In order to get login process through, one has to use linkedIn web page authorization step; No way we can have third party app accepting credentials and making linkedIn authorization with the link https://api.linkedin.com/uas/oauth/authorize?oauth_token=$oauthtoken

Answer 2

I think I understand what you are asking and the answer is no you cannot do that with LinkedIn. I have been facing similar problem recently and wasn't able to solve it. I guess the LinkedIn guys have a good point about data protecting and stuff.
Check this out:
http://developer.linkedin.com/message/6460
http://getsatisfaction.com/linkedin/topics/cant_use_linkedin_api_to_view_public_profiles_without_oauth_login