TLS v1.2

[herrmann30]

Campaign Monitor recently sent out an email asking all customers to switch over to TLS v1.2 before October 12, 2020. Our website is using this code. How do I know what version of TLS we are using? Does this code support TLS v1.2?

[LiamKarlMitchell]

https://stackoverflow.com/questions/27904854/verify-if-curl-is-using-tls

I modified pub/index.php (Magento 2 hosting with nginx) it shows we are using TLS 1.3 so I assume it is fine, but not sure if there needs to be an update to this library to switch it into this newer version I would assume it is done automatically but would be nice to know for sure?

if (isset($_GET['testssl'])) {
$ch = curl_init('https://www.howsmyssl.com/a/check');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$data = curl_exec($ch);
curl_close($ch);

$json = json_decode($data);
echo $json->tls_version;
die();
}

[LiamKarlMitchell]

curl_setopt ($ch, CURLOPT_SSLVERSION, 6)

https://stackoverflow.com/questions/30145089/tls-1-2-not-working-in-curl

CURL_SSLVERSION_DEFAULT (0)
CURL_SSLVERSION_TLSv1 (1)
CURL_SSLVERSION_SSLv2 (2)
CURL_SSLVERSION_SSLv3 (3)
CURL_SSLVERSION_TLSv1_0 (4)
CURL_SSLVERSION_TLSv1_1 (5)
CURL_SSLVERSION_TLSv1_2 (6).

http://php.net/manual/en/function.curl-setopt.php

Can be set explicitly, correct place for this looks to be class/transport.php
Thoughts?