JavaScript: Check TLS level of browser and remove matching domain links from page if browser does not meet minimum requirement

check-tls.js

// domains to check
var checkDomains = ['www.foobar.com', 'www.fubar.com'];

// check all links in DOM for matching domain(s)
var matchingLinks = [];
var documentLinks = document.links;
for (var i = 0; i < documentLinks.length; i++) {
	if (checkDomains.indexOf(documentLinks[i].hostname) > -1)
		matchingLinks.push(documentLinks[i]);
}
if (matchingLinks.length > 0) {
	checkTLS('https://www.howsmyssl.com/a/check?callback=parseTLS', parseTLS);
}

// inserts TLS API script into DOM
function checkTLS(url, callback) {
	var newScript = document.createElement('script');
	newScript.type = 'text/javascript';
	newScript.src = url;
	var s = document.getElementsByTagName('script')[0];
	s.parentNode.insertBefore(newScript, s);
};

// interpret response from TLS API
function parseTLS(reponse) {
	if (reponse.tls_version.split(' ')[1] < 1.2) {
    //disableLinks();
	  alert('Your browser may not support the minimum security requirements for online payments.\n\nIf you receive an error message when attempting payments, please upgrade to the latest browser version');
  }
};

// disable all matching links
function disableLinks() {
	for (var i = 0; i < matchingLinks.length; i++) {
		var span = document.createElement('span');
		if (matchingLinks[i].className)
			span.className = matchingLinks[i].className;
		if (matchingLinks[i].id)
			span.id = matchingLinks[i].id;
		span.innerHTML = matchingLinks[i].innerHTML;
		span.style.setProperty('text-decoration', 'line-through');
		matchingLinks[i].parentNode.replaceChild(span, matchingLinks[i]);
		console.log('Disabled link: ' + matchingLinks[i]);
	}
}

check-ts.md

Check users' browsers before they navigate a link which requires minimum recommended TLS security.

If browser does not meet required TLS level then disable relevant links and give warning. Only checks TLS if matching link domains found.

Uses TLS checking API from www.howsmyssl.com

Add to page with following:

<script src="check-tls.js"></script>