Import Google contacts using Authsub(Secure connection)

[Paresh1462]

Hello friends, I am learning google API I want to retrieve google contacts using Authsub. And second thing is that i want to use secure token. I have X.509 certificate with private key. In first step I got token but in second step (To get AuthSubSessionToken) I got error : Invalid AuthSub token. Here my code. please, anybody have idea ? Help me....

$url = "https://www.google.com/accounts/AuthSubSessionToken";
$token = $token;
$param['sigalg'] = "rsa-sha1";
$nonce = "15948".time()."49418"; // any random no(20 digit)
$param['data'] = "GET https://www.google.com/accounts/AuthSubSessionToken ".time()." ".$nonce;
$private_key = "MY_PRIVATE_KEY";

$kvpairs = array();
foreach ($param as $k => $v) {
array_push($kvpairs, ($k . '=' . $v));
}
$query_string = '';
$query_string = implode('&', $kvpairs);
$base_string = 'GET'.'&'.$url .'&'.$query_string;
$param['sig'] = base64_encode(hash_hmac('sha1', $base_string, $private_key, true));
uksort($param, 'strcmp');
$header = 'Authorization: AuthSub token="'.$token.'" ';
foreach ($param as $k => $v)
{
$header .= $k . '="' .$v. '" ';
}

    $header = trim($header," ");
$headers\[\]= $header;
$ch = curl\_init();
curl\_setopt($ch, CURLOPT\_URL,$url);
curl\_setopt($ch, CURLOPT\_RETURNTRANSFER, true);
curl\_setopt($ch, CURLOPT\_SSL\_VERIFYPEER, false);
curl\_setopt($ch, CURLOPT\_HTTPHEADER, $headers);
$responce = curl\_exec($ch);
curl\_close($ch);