With the new HTTP/2 APNS provider API, you can use curl to send push notifications.
EDIT
Before proceeding (as noted by @Madox), openssl >= 1.0.2e of should be installed (from package preferably). Verify with the command
openssl version
a) Your version of PHP should be >= 5.5.24 so that the constant CURL_HTTP_VERSION_2_0 is defined.
b) Make sure that you have curl version 7.46+ installed in your system with
curl --version
c) Curl should have http/2 support enabled. In the output when typing the previous command, you should see a line like this one:
Features: IDN IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP HTTP2 UnixSockets
if HTTP2 doesn't show up, you can follow this excellent tutorial to install http/2 for curl https://serversforhackers.com/video/curl-with-http2-support
Verify that curl detected openssl >= 1.0.2e, doing curl --version should output something like this:
curl 7.47.1 (x86_64-pc-linux-gnu) libcurl/7.47.1 OpenSSL/1.0.2f zlib/1.2.8 libidn/1.28 nghttp2/1.8.0-DEV librtmp/2.3
e) Once you everything installed, you can test it in the command line:
curl -d '{"aps":{"alert":"hi","sound":"default"}}' \
--cert <your-certificate.pem>:<certificate-password> \
-H "apns-topic: <your-app-bundle-id>" \
--http2 \
https://api.development.push.apple.com/3/device/<device-token>
f) Here is a sample code in PHP that I have successfully tried:
if(defined('CURL_HTTP_VERSION_2_0')){
$device_token = '...';
$pem_file = 'path to your pem file';
$pem_secret = 'your pem secret';
$apns_topic = 'your apns topic. Can be your app bundle ID';
$sample_alert = '{"aps":{"alert":"hi","sound":"default"}}';
$url = "https://api.development.push.apple.com/3/device/$device_token";
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_POSTFIELDS, $sample_alert);
curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("apns-topic: $apns_topic"));
curl_setopt($ch, CURLOPT_SSLCERT, $pem_file);
curl_setopt($ch, CURLOPT_SSLCERTPASSWD, $pem_secret);
$response = curl_exec($ch);
$httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
//On successful response you should get true in the response and a status code of 200
//A list of responses and status codes is available at
//https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/TheNotificationPayload.html#//apple_ref/doc/uid/TP40008194-CH107-SW1
var_dump($response);
var_dump($httpcode);
}
