Sending Apple push notifications with APN service and .p8 key

Sending Apple push notifications with APN service and .p8 key .php

<?php

// Path to the .p8 file downloaded from apple
// see: https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/establishing_a_token-based_connection_to_apns#2943371
$authKey = "AuthKey_S97G28Y3JP.p8";

// Team ID (From the Membership section of the ios developer website)
// see: https://developer.apple.com/account/
$teamId = 'asdfasdf';

// The "Key ID" that is provided when you generate a new key
$tokenId = 'asdfasdf';

// The Bundle ID of the app you want to send the notification to
$bundleId = 'com.companyname.appname';

// Device token (registration id)
$devToken = 'asdfasdf908sd7f987sdf987asd9f87a9df790ads7f9afd7s90adf79a0fd7';

// The content of the push notification
// see: https://developer.apple.com/library/archive/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/CreatingtheNotificationPayload.html#//apple_ref/doc/uid/TP40008194-CH10-SW1
$notification_payload = [
	'alert' => [
		'title' => "Big Test",
		'body' => "Big body test"
	]
];

// For development, turn to false
$production = true;

################################################################################
## Generate JWT ################################################################
################################################################################

function b64($raw, $json=false){
	if($json) $raw = json_encode($raw);
	return str_replace('=', '', strtr(base64_encode($raw), '+/', '-_')); 
}

$token_key = file_get_contents($authKey);

$jwt_header = [
	'alg' => 'ES256', 
	'kid' => $tokenId
];

$jwt_payload = [
	'iss' => $teamId, 
	'iat' => time()
];

$raw_token_data = b64($jwt_header, true).".".b64($jwt_payload, true);

$signature = '';

openssl_sign($raw_token_data, $signature, $token_key, 'SHA256');

$jwt = $raw_token_data.".".b64($signature);

################################################################################
## Send Message ################################################################
################################################################################

$request_body = json_encode($notification_payload);
$endpoint = $production ? 'https://api.push.apple.com/3/device': 'https://api.development.push.apple.com/3/device';
$url = "$endpoint/$devToken";

$ch = curl_init($url);
curl_setopt_array($ch, [
	CURLOPT_POSTFIELDS => $request_body,
	CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_2_0,
	CURLOPT_HTTPHEADER => [
		"content-type: application/json",
		"authorization: bearer $jwt",
		"apns-topic: $bundleId"
	]
]);
$response = curl_exec($ch);
$httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
$err = curl_error($ch);
curl_close($ch);

################################################################################
## Do something with output ####################################################
################################################################################

header('Content-Type: text/plain');

echo "-----";
echo "HTTP Code: $httpcode\n";
echo "cURL Error: ".var_export($err, true)."\n";
echo "Response: \n$response\n";