Office365 OAuth - Token via CURL - php

Question

I'm trying to connect to the Azure platform to grab a response, mainly to get the token for use when accessing an office365 mailbox
The following is what i'm using, but I always get a NULL response
What other CURLOPT_POSTFIELDS need to be included, or what else needs to be changed.
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => "https://login.microsoftonline.com/".$tennantid."/oauth2/v2.0/authorize",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => '',
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 0,
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_POSTFIELDS => 'client_id='.$appid.'&response_type=token&scope=https://graph.microsoft.com/User.Read&redirect_uri='.$uri,
CURLOPT_HTTPHEADER => array(
'Content-Type: application/x-www-form-urlencoded'
),
));
$response = curl_exec($curl);
$response_decode = json_decode($response);
var_dump($response_decode);
curl_close($curl);
I currently get the token back ok when I use the following method
$params = array ('client_id' =>$appid,
'redirect_uri' =>$uri,
'response_type' =>'token',
'response_mode' =>'form_post',
'scope' =>'https://graph.microsoft.com/User.Read',
'state' =>$_SESSION['state']);
header ('Location: '.$login_url.'?'.http_build_query ($params));
Which works fine.
But I need to do CURL method as I need this running background cron job task
What do I seem to be missing?
Thanks in advance

Answer 1

A link to the API documentation may have helped. Without that I cannot help much. Just one obvious thing.
You are using Content-Type: application/x-www-form-urlencoded
You are not encoding the data. From MDN:
application/x-www-form-urlencoded: the keys and values are encoded in
key-value tuples separated by '&', with a '=' between the key and the
value. Non-alphanumeric characters in both keys and values are percent
encoded: this is the reason why this type is not suitable to use with
binary data (use multipart/form-data instead)
Source: MDN Post data
This would mean your request data should look like this:
client_id%3D1234%26response_type%3Dtoken%26scope%3Dhttps%3A%2F%2Fgraph.microsoft.com%2FUser.Read%26redirect_uri%3Dhttp%3Aexample.com
Try this:
$post = urlencode('client_id='.$appid.'&response_type=token&scope=https://graph.microsoft.com/User.Read&redirect_uri=http:example.com');
CURLOPT_POSTFIELDS => $ post,