How to debug PHP cURL SSL/TLS parameters

debug-curl-tls.php

<?php

$ch = curl_init('https://www.google.com/');
$verbose = fopen('php://temp', 'w+');

curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
curl_setopt($ch, CURLOPT_VERBOSE, TRUE);
curl_setopt($ch, CURLOPT_STDERR, $verbose);

curl_exec($ch);
curl_close($ch);

rewind($verbose);
$stderr_lines = explode("\n", stream_get_contents($verbose));
$tls_nego = array();
foreach($stderr_lines as $line)
{
	if (preg_match_all('/^\* Connected to (.*) \(.* port (.*) \(.*$/', $line, $matches) != 0)
	{
		$server = $matches[1][0] . ':' . $matches[2][0];
	}
	if (preg_match_all('/^\* (.*) connection using (.*)$/', $line, $matches) != 0)
	{
		$tls_nego[$server] = array($matches[1][0], $matches[2][0]);
	}
}

print_r($tls_nego);

Array
(
    [www.google.com:443] => Array
        (
            [0] => TLS 1.2
            [1] => TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
        )

    [www.google.fi:443] => Array
        (
            [0] => TLS 1.2
            [1] => TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
        )

)