Apple news API. PHP code for Connect and send json data - php

Question

I am able to connect with the help of apple news api but I can't able to send data in json format.
My code is below.
but when I try to attach json file. I am getting signature failure message.
<?php
$channel_id = 'xxxxxxxxxxxxxxxxxx';
$api_key_id = 'xxxxxxxxxxxxxxx';
$api_key_secret = 'xxxxxxxxxxxxxxxx';
// use the correct values above
$data = file_get_contents('article.json');
$Content_type="application/json";
$url = 'https://news-api.apple.com/channels/'.$channel_id;
$date = gmdate('Y-m-d\TH:i:s\Z');
$canonical_request = 'GET'.$url.$date.$Content_type;
$key = base64_decode($api_key_secret);
$hashed = hash_hmac('sha256', $canonical_request,$key,true);
$signature = base64_encode($hashed);
echo $signature;
//curl options
$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_URL, $url);
$headers = array();
$headers[] = "Authorization: HHMAC; key={$api_key_id}; signature={$signature}; date={$date}";
$headers[] = "Content-Type: application/json";
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
//curl_setopt($ch, CURLOPT_POST, true);
//curl_setopt( $ch, CURLOPT_POSTFIELDS, $data);
//get result
$server_output = curl_exec ($ch);
curl_close ($ch);
print_r(json_decode($server_output));
?>

Answer 1

Since you are sending a GET request, you are incorrectly including the content type when building the canonical request.
This should work for you, then:
$canonical_request = 'GET'.$url.$date;
For reference, see Apple News API Reference: Setting Up MAC/HMAC Authentication:
Create a canonical version of the request as a byte-wise concatenation of the following:
The HTTP method (for example, GET or POST, in all caps)
The full URL of the request
The current date in ISO 8601 format
If the request is a POST request and it includes an entity, include the following:
The value of the Content-Type header
The full content of the entity