How to access phpbb3 through an iframe without getting logged out

Question

Due to new security settings implemented in most browsers (though not Firefox as of 8/21), users were getting logged out of phpbb3 when looking at messages or pressing "New Topic". The relevant phpbb feature request is low priority and hasn't seen activity for about a year.

Answer 1

I made browsers such as IE, Edge, and Chrome work for our bulletin board by going into phpbb/session.php and adding "samesite=None;" to the last command in the function set_cookie():

header('Set-Cookie: ' . $name_data . (($cookietime) ? '; samesite=None;  expires=' . $expire : '') . '; path=' . $config['cookie_path'] . $domain . ((!$config['cookie_secure']) ? '' : '; secure') . ';' . (($httponly) ? ' HttpOnly' : ''), false);