<html> <head>

<title>U2F Challenge</title>
<style type="text/css"><!--
body {
  background: #232526;  /* fallback for old browsers */
background: -webkit-linear-gradient(to top, #414345, #232526);  /* Chrome 10-25, Safari 5.1-6 */
background: linear-gradient(to top, #414345, #232526); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
}
body, html {
  color: #fff;
  font-family: monospace;
}
div.main {
  margin-left: auto;
  margin-right: auto;
  width: 60%;
  margin-top: 10%;
}
--></style>

</head> <body> <form method=“post”>

<input type="hidden" name="u2f_auth">

</form>

<script type=“text/javascript”>

{{{u2fjs}}}

var appId = {{{app_id}}}; var challenge = {{{challenge}}}; var signRequests = {{{sign_requests.as_json}}}; u2f.sign(appId, challenge, signRequests, function(signResponse) {

var form, reg, response;

if (signResponse.errorCode) {
  return alert("Authentication error: " + signResponse.errorCode);
}

form = document.forms[0];
response = document.querySelector('[name=u2f_auth]');

response.value = JSON.stringify(signResponse);

form.submit();

}); </script>

<div class=“main”> <h1>U2F Auth</h1> <p>Insert your token and authenticate.</p> </div> </body> </html>