閲覧者の自己署名証明書 有効期限を出力

参考

• http://web.mit.edu/~geofft/web_scripts/detect.php
• http://lifescied.org/mod/mod_ssl.html

値

• $_SERVER['SSL_CLIENT_V_END'] に 閲覧者の有効期限が入っている。

function check_ssl_client_v_end() {
        if (empty($_SERVER['SSL_CLIENT_V_END'])) {
                //echo "no ssl";
                return false;
        }
        if (strtotime($_SERVER['SSL_CLIENT_V_END']) < strtotime("+3 month")) {
            echo "[warning] Your certificate will expire on ";
            echo date("Y-m-d D", strtotime($_SERVER['SSL_CLIENT_V_END']));
        }
}

check_ssl_client_v_end();