libevent SSL client certificate initialization for Apple Push Notifications service connection

apple_push_client_cert.c

static void
init_feedback_service(struct event_base *ev_base, struct evdns_base *dns)
{
   int rc;
   struct bufferevent *bev;
   SSL_CTX *ssl_ctx;
   SSL *ssl;

   ssl_ctx = SSL_CTX_new(SSLv3_method());

   rc = SSL_CTX_use_certificate_file(ssl_ctx, "my_apple_cert_and_key.pem", SSL_FILETYPE_PEM);
   if (rc != 1) {
       errx(EXIT_FAILURE, "Could not load certificate file");
   }
   rc = SSL_CTX_use_PrivateKey_file(ssl_ctx, "my_apple_cert_and_key.pem", SSL_FILETYPE_PEM);
   if (rc != 1) {
       errx(EXIT_FAILURE, "Could not load private key file");
   }

   ssl = SSL_new(ssl_ctx);
   bev = bufferevent_openssl_socket_new(ev_base, -1, ssl, BUFFEREVENT_SSL_CONNECTING, BEV_OPT_CLOSE_ON_FREE);
   bufferevent_setcb(bev, feedback_read_cb, NULL, feedback_event_cb, NULL);
   rc = bufferevent_socket_connect_hostname(bev, dns, AF_INET, "feedback.sandbox.push.apple.com", 2196);
   if (rc < 0) {
       warnx("could not connect to feedback service: %s",
             evutil_socket_error_to_string(EVUTIL_SOCKET_ERROR()));
       bufferevent_free(bev);
       return;
   }
   bufferevent_enable(bev, EV_READ);
}