linkedin API using raw PHP

Question

I want to get the profile info after getting the token

<?php

    session_start ();

    if (!$_SESSION['linkedin_access_token'])
    {
        echo 'Grant access first';
        exit ();
    }

    ## step 0
    define ('LINKEDIN_KEY', 'xxxxxx');
    define ('LINKEDIN_SECRET', 'xxxxxxx');

    function urlencode_oauth ($str)
    {
        return str_replace ('+', ' ', str_replace ('%7E', '~', rawurlencode ($str)));
    }

    $links = array (
        'request_token' => 'https://api.linkedin.com/uas/oauth/requestToken',
        'authorize' => 'https://www.linkedin.com/uas/oauth/authorize',
        'access_token' => 'https://api.linkedin.com/uas/oauth/accessToken',
    );


    ## step 2
    $params = array (
        'oauth_consumer_key' => LINKEDIN_KEY,
        'oauth_nonce' => sha1 (microtime ()),
        'oauth_signature_method' => 'HMAC-SHA1',
        'oauth_timestamp' => time (),
        'oauth_token' => $_SESSION ['linkedin_access_token'],
        'oauth_version' => '1.0'
    );

    ## step 3
    // sort parameters according to ascending order of key
    // sort parameters according to ascending order of key
    ksort ($params);

    // prepare URL-encoded query string
    $q = array ();
    foreach ($params as $key => $value)
    {
        $q [] = urlencode_oauth ($key) . '=' . urlencode_oauth ($value);
    }
    $q = implode ('&', $q);

    // generate the base string for signature
    $parts = array (
        'POST',
        urlencode_oauth ('https://api.linkedin.com/v1/people/~'),
        urlencode_oauth ($q)
    );
    $base_string = implode ('&', $parts);

    ## step 4
    $key = urlencode_oauth (LINKEDIN_SECRET) . '&' . urlencode_oauth ($_SESSION ['linkedin_access_token_secret']);
    $signature = base64_encode (hash_hmac ('sha1', $base_string, $key, true));

    ## step 5
    $params ['oauth_signature'] = $signature;
    $str = array ();
    foreach ($params as $key => $value)
    {
        $str [] = $key . '="' . urlencode_oauth ($value) . '"';
    }
    $str = implode(', ', $str);
    $headers = array (
        'POST /v1/people/~ HTTP/1.1',
        'Host: api.linkedin.com',
        'Authorization: OAuth ' . $str,
        'Content-Type: text/xml;charset=UTF-8',
        'Content-Length: 0',
        'Connection: close'
    );

    ## step 6
    $fp = fsockopen ("ssl://api.linkedin.com", 443, $errno, $errstr, 30);
    if (!$fp)
    {
        echo 'Unable to connect to LinkedIn';
        exit();
    }
    $out = implode ("\r\n", $headers) . "\r\n\r\n";
    fputs ($fp, $out);

    // getting LinkedIn server response
    $res = '';
    while (!feof ($fp)) $res .= fgets ($fp, 4096);
    fclose ($fp);

    echo '<pre>';
    echo $res . "\n\n";
    echo $_SESSION ['linkedin_access_token'] . "\n" . $_SESSION ['linkedin_access_token_secret'];

 ?>

What's wrong with it? it shows me

HTTP/1.1 405 Method Not Allowed
Server: Apache-Coyote/1.1
x-li-request-id: H8M76QXW5O
Date: Tue, 04 Sep 2012 12:09:21 GMT
Vary: *
x-li-format: xml
Content-Type: text/xml;charset=UTF-8
Content-Length: 262

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<error>
  <status>405</status>
  <timestamp>1346760561727</timestamp>
  <request-id>H8M76QXW5O</request-id>
  <error-code>0</error-code>
  <message>Unsupported POST target {/v1/people/~}</message>
</error>


xxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxx

Answer 1

define('LINKEDIN_KEY', 'YOUR_KEY');
define('LINKEDIN_SECRET', 'YOUR SECRET');

function urlencode_oauth($str) {
return str_replace('+',' ',str_replace('%7E','~',rawurlencode($str)));
}
$links = array(
 'request_token'=>'https://api.linkedin.com/uas/oauth/requestToken',
  'authorize'=>'https://www.linkedin.com/uas/oauth/authorize',
  'access_token'=>'https://api.linkedin.com/uas/oauth/accessToken'
);
$params = array(
  'oauth_callback'=>"YOUR CALLBACK URL",
  'oauth_consumer_key'=>LINKEDIN_KEY,
  'oauth_nonce'=>sha1(microtime()),
  'oauth_signature_method'=>'HMAC-SHA1',
  'oauth_timestamp'=>time(),
  'oauth_version'=>'1.0'
);
    // sort parameters according to ascending order of key
    ksort($params);

    // prepare URL-encoded query string
    $q = array();
    foreach ($params as $key=>$value) {
      $q[] = urlencode_oauth($key).'='.urlencode_oauth($value);
    }
    $q = implode('&',$q);

    // generate the base string for signature
    $parts = array(
      'POST',
      urlencode_oauth($links['request_token']),
      urlencode_oauth($q)
    );
    $base_string = implode('&',$parts);
    $key = urlencode_oauth(LINKEDIN_SECRET) . '&';
    $signature = base64_encode(hash_hmac('sha1',$base_string,$key,true));

    $params['oauth_signature'] = $signature;
    $str = array();
    foreach ($params as $key=>$value) {
      $str[] = $key . '="'.urlencode_oauth($value).'"';
    }
    $str = implode(', ',$str);
    $headers = array(
      'POST /uas/oauth/requestToken HTTP/1.1',
      'Host: api.linkedin.com',
      'Authorization: OAuth '.$str,
      'Content-Type: text/xml;charset=UTF-8',
      'Content-Length: 0',
      'Connection: close'
    );
    $fp = fsockopen("ssl://api.linkedin.com",443,$errno,$errstr,30);
    if (!$fp) { echo 'Unable to connect to LinkedIn'; exit(); }
    $out = implode("\r\n",$headers) . "\r\n\r\n";
    fputs($fp,$out);

    // getting LinkedIn server response
    $res = '';
    while (!feof($fp)) $res .= fgets($fp,4096);
    fclose($fp);

    $parts = explode("\n\n",str_replace("\r",'',$res));
    $res_headers = explode("\n",$parts[0]);
    if ($res_headers[0] != 'HTTP/1.1 200 OK') {
      echo 'Error getting OAuth token and secret.'; exit();
    }
    parse_str($parts[1],$data);
    if (empty($data['oauth_token'])) {
      echo 'Failed to get LinkedIn request token.'; exit();
    }

Replace three things 1. 'YOUR_KEY' 2. 'YOUR_SECRET' and 3.'oauth_callback'.

Thanks,

Anand

Answer 2

As the documentation indicates, the Profile API does not support the POST method. Try using GET instead to retrieve profile data.