Detecting SSL With PHP [duplicate]

Answer 1

$_SERVER['HTTPS']

Set to a non-empty value if the script was queried through the HTTPS protocol.
Note: Note that when using ISAPI with IIS, the value will be off if the request was not made through the HTTPS protocol.

http://www.php.net/manual/en/reserved.variables.server.php

Ergo, this'll do:

if (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] != 'off') {
    // SSL connection
}