WordPress behind HTTPS reverse proxy

wp-admin.php

if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
  $ips = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
  $_SERVER['REMOTE_ADDR'] = $ips[0];
}

// If we're behind a proxy server and using HTTPS, we need to alert Wordpress of that fact
// see also http://codex.wordpress.org/Administration_Over_SSL#Using_a_Reverse_Proxy
if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https') {
    $_SERVER['HTTPS'] = 'on';
}