Question

I am writing following code to get authorization token.

assigning authorization to code variable

$code =  $this->request->query['code'];

i have deleted my client secret to post question.

$clientSecret = "";

initializing curl

        $ch = curl_init();
        $header[]         = "Content-Type: application/x-www-form-urlencoded";

        curl_setopt($ch, CURLOPT_HTTPHEADER,     $header);
        curl_setopt($ch, CURLOPT_POST,        true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, urlencode("code=".$code."&
                client_id=289710071999.apps.googleusercontent.com&
                client_secret=".$clientSecret."&
                redirect_uri=http://budzzflorist.localhost.com/users/google&
                grant_type=authorization_code"));
        curl_setopt($ch, CURLOPT_URL, "https://accounts.google.com/o/oauth2/token");
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $request_result = curl_exec($ch);
        print_r(curl_getinfo($ch));
        echo "\n\ncURL error number:" .curl_errno($ch); // print error info
        echo "\n\ncURL error:" . curl_error($ch);
        var_dump( json_decode($request_result,true));

Answer 1

It looks like Google wants the form to be application/x-www-urlencoded.

Try this:

$ch           = curl_init();
$code         = '123';
$clientSecret = '45686';

$postFields = array('code'          => $code,
                    'client_id'     => '289710071999.apps.googleusercontent.com',
                    'client_secret' => $clientSecret,
                    'redirect_uri'  => 'http://budzzflorist.localhost.com/users/google',
                    'grant_type'    => 'authorization_code');

curl_setopt($ch, CURLOPT_POST,        true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($postFields));
curl_setopt($ch, CURLOPT_URL, "https://accounts.google.com/o/oauth2/token");
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$request_result = curl_exec($ch);

var_dump( json_decode($request_result,true));

Result: invalid_client because my tokens are incorrect, but not invalid_request.

If you pass an array to CURLOPT_POSTFIELDS, cURL will force the content type to be multipart/form-data which is what causes invalid request. Instead use http_build_query which creates a url-encoded query string from an array based on key-value pairs. Then pass the result of that to CURLOPT_POSTFIELDS.