title: LinkedIn Api - Uncaught exception 'OAuthException'
body: <p>I'm currently attempting to install a login button for LinkedIn onto my website. I'm trying to go step by step as the developers section shows. After I wrote the code to get a request token and checked it using print_r. </p>
  
  <pre><code>define("my consumer key");
  define("my consumer secret");
  
  $oauth = new OAuth(my consumer key, my consumer secret);
  
  //The first item of business is getting a request token
  $request_token_response = $oauth-&gt;getRequestToken('https://api.linkedin.com/uas/oauth/requestToken');
  
  if($request_token_response === FALSE) {
          throw new Exception("Failed fetching request token, response was:"
          . $oauth-&gt;getLastResponse());
  } else {
          $request_token = $request_token_response;
  }
  
  print "Request Token:\n";
  printf("    - oauth_token        = %s\n", $request_token['oauth_token']);
  printf("    - oauth_token_secret = %s\n", $request_token['oauth_token_secret']);
  print "\n";
  </code></pre>
  
  <p>I got "Fatal error:Uncaught exception 'OAuthException'...Peer certificate cannot be authenticated with known CA certificates". The line that was called for the error is below</p>
  
  <pre><code>$request_token_response = $oauth-&gt;getRequestToken('https://api.linkedin.com/uas/oauth/requestToken');
  </code></pre>
  
  <p>I am not understanding what that error is trying to tell me so that I can fix the problem. I would appreciate and tips or guidance to help me better understand what this error message is trying to convey and how to fix it.</p>