I want to get the ssl session id so I know that it is the same user. When I try $_SERVER['ssl_session_id'] it returns nothing and doing print_r($_SERVER) $_SERVER['ssl_session_id'] doesn’t show up.
The reason I need to have the ssl session id is I’m creating a login system and would like to make sure the session can’t be used through a fixation attack. I am going to add it to the auth session cookie and then can check it later.
EDIT:
From the answers and comments I have gotten:
It changes every request and isn’t something that is stored in a $_SERVER or $_SESSION super global array; therefore is useless for using on the web and shouldn’t be used.
What I have learned from comments and research is that you can’t get the ssl_session_id through PHP and even if you could it changes therefore isn’t useful. Thank you to the people who answered and commented.