PHP Tools for Visual Studio 2022 1.85.17447
I'm attempting to verify that my web host has a DigiCert global certificate installed, so I'm making a PHP 8.3 curl call using a downloaded root certificate from DigiCert, but for the life of me I can't get past the "SSL certificate problem: unable to get local issuer certificate" error. I'm pretty sure this is some kind of config problem as all the suggestions I've extensively researched have failed.

I've tried setting the [curl] curl.cainfo and [openssl] openssl.cafile in php.ini to no avail. It's always able to find the file, it just can't read it for some reason. Is this an issue with the curl lib on windows that PHP tools is using not being able to read a local pem file? I set security on the pem file to "everyone". I also tried copying it to the same folder that the php.ini lives. No love.

<?php
$url = "https://mywebsite.com"; // Replace with the target URL
$certPath = "C:\\Users\\xxx\\Desktop\\DigiCertGlobalRootG2.crt.pem"; // Path to the DigiCert certificate

// Initialize cURL
$ch = curl_init();

// Set cURL options
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true); // Enable SSL certificate verification
curl_setopt($ch, CURLOPT_CAINFO, $certPath); // Path to the DigiCert certificate
curl_setopt($ch, CURLOPT_VERBOSE, true); // Enable verbose output
// Open a file to log verbose output
$verboseLog = fopen('php://temp', 'w+');
curl_setopt($ch, CURLOPT_STDERR, $verboseLog);
$response = curl_exec($ch);
// Check for errors
if (curl_errno($ch)) {
	echo "cURL error: " . curl_error($ch);
} else {
	echo "Response: " . $response;
	// Retrieve verbose output
}
rewind($verboseLog);
$verboseOutput = stream_get_contents($verboseLog);
echo "<pre>" . htmlspecialchars($verboseOutput) . "</pre>";
curl_close($ch);
fclose($verboseLog);
?>

Output:

cURL error: SSL certificate problem: unable to get local issuer certificate
* Host mywebsitewhatevers.com:443 was resolved.
* IPv6: (none)
* IPv4: 111.111.111.111
*   Trying 111.111.111.111:443...
* Connected to mywebsitewhatevers.com: (111.111.111.111) port 443
* ALPN: curl offers h2,http/1.1
*  CAfile: C:\Users\xxx\Desktop\DigiCertGlobalRootG2.crt.pem
*  CApath: none
* SSL certificate problem: unable to get local issuer certificate
* Closing connection

The local pem file looks like this:

I exported the same DigiCert Global Root G2 certificate from my windows cert store and it exported the exact same thing so that looks correct. Or is that the wrong format for curl??