How should PHP/IIS be configured to work with the VK API over HTTPS?

Question

PHP

I log in, I get the code necessary to get an access_token, but I can't get it because of the following error:

file_get_contents(): SSL operation failed with code 1. OpenSSL Error messages:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed

Tried to create a context:

<?php
$arrContextOptions=array(
    "ssl"=>array(
        "verify_peer"=>false,
        "verify_peer_name"=>false,
    ),
);  

$response = file_get_contents("https://maps.co.weber.ut.us/arcgis/rest/services/SDE_composite_locator/GeocodeServer/findAddressCandidates?Street=&SingleLine=3042+N+1050+W&outFields=*&outSR=102100&searchExtent=&f=json", false, stream_context_create($arrContextOptions));

echo $response; ?>

It doesn't help, it throws a non authorized error.
Also, I tried to get a free certificate. I downloaded the file with the *.cer extension, registered the path in php.ini:

openssl.cafile="C:\Program Files (x86)\PHP\v5.6\extras\ssl\cert.cer"

But it did not help, PHP says that the certificate is not valid.