Secure your communications with Apple Push Notification service (APNs) by using stateless authentication Tokens.
First you must obtain an Encryption Key and a Key ID from Apple Developer Account. Once a successful registration, you will obtain a 10-Character string with the Key ID and an Authentication Token signing key as a .p8 file extension.
You must use the sgcWebSockets JWT Client to generate a JWT using ES256 as algorithm. The token must not be generated for every HTTP/2 request, the token must not be refreshed before 20 minutes and not after 60 minutes.
Configure the JWT Client with the following values:
Using Token-Based connections, requires to send the apns-topic with the value of your app's bundle ID/app id (example: com.example.application).
oHTTP := TsgcHTTP2Client.Create(nil);
oHTTP.TLSOptions.IOHandler := iohOpenSSL;
oJWT := TsgcHTTP_JWT_Client.Create(nil);
oHTTP.Authentication.Token.JWT := oJWT;
oJWT.JWTOptions.Header.alg := jwtES256;
oJWT.JWTOptions.Header.kid := 'apple key id';
oJWT.JWTOptions.Payload.iss := 'issuer';
oJWT.JWTOptions.Payload.iat := StrToInt64(GetDateTimeUnix(Now, False));
oJWT.JWTOptions.Algorithms.ES.PrivateKey.LoadFromFile('AuthKey_**.p8');
oJWT.JWTOptions.RefreshTokenAfter := 60*40;
oHTTP.Request.CustomHeaders.Clear;
oHTTP.Request.CustomHeaders.Add('apns-topic: com.example.application');