Andrew Boyson / web

Common stuff for all my devices' web server pages: css, login, log, ipv4, ipv6, firmware update, clock, reset info etc.

Dependents:   oldheating gps motorhome heating

Security

A password has to be set whenever there has been a software reset. Resets following faults or power on do not require a new password as the hash is restored from the RTC GPREG register.

The password is not saved on the device; instead a 32 bit hash of the password is saved. It would take 2^31 attempts to brute force the password: this could be done in under a month if an attempt were possible every millisecond. To prevent this a 200 ms delay is introduced in the reply to the login form, that gives a more reasonable 13 years to brute force the password.

Once the password is accepted a random session id is created. This is 36 bit to give six base 64 characters but without an extra delay. If an attempt could be made every ms then this would still take over a year to brute force.

The most likely attack would to use a dictionary with, say, 10 million entries against the password which would still take 20 days to do.

base/clock/web-clock-html.c

Committer:
andrewboyson
Date:
2019-09-24
Revision:
130:9a5b8fe308f1
Parent:
124:a2de6c22f85e

File content as of revision 130:9a5b8fe308f1:

#include <time.h>

#include "http.h"
#include "web-nav-base.h"
#include "web-add.h"

void WebClockHtml()
{
    HttpOk("text/html; charset=UTF-8", "no-cache", NULL, NULL);
    WebAddHeader("Clock", "settings.css", "clock.js");
    WebAddNav(CLOCK_PAGE);
    WebAddH1("Clock");
    
    WebAddH2("Status");
    WebAddAjaxLed("RTC is set"           , "ajax-rtc-set"    );
    WebAddAjaxLed("Clock is set"         , "ajax-clock-set"  );
    WebAddAjaxLed("External source is ok", "ajax-source-ok"  );
    WebAddAjaxLed("Time synchronised"    , "ajax-time-locked");
    WebAddAjaxLed("Rate synchronised"    , "ajax-rate-locked");
    
    WebAddH2("Server UTC time");
    HttpAddText("<div id='ajax-date-utc'></div>\r\n");

    WebAddH2("Server local time");
    HttpAddText("<div id='ajax-date-pc'></div>\r\n");
    
    WebAddH2("Server - PC (ms)");
    HttpAddText("<div id='ajax-date-diff'></div>\r\n");    
    
    WebAddH2("UTC");
    WebAddAjaxInputToggle("Enable epoch change"     ,    "ajax-leap-enable"  , "chg-clock-leap-enable" );
    WebAddAjaxInputToggle("Direction of next epoch" ,    "ajax-leap-forward" , "chg-clock-leap-forward");
    WebAddAjaxInput      ("Year next epoch starts"  , 4, "ajax-leap-year"    , "set-clock-leap-year"   );
    WebAddAjaxInput      ("Month next epoch starts" , 4, "ajax-leap-month"   , "set-clock-leap-month"  );
    WebAddAjaxInput      ("Current era offset"      , 4, "ajax-leap-count"   , "set-clock-leap-count"  );

    HttpAddText("<div><button type='button' onclick='displayLeap()'>Display leap</button></div>\r\n");
    
    HttpAddText("<div>The leap seconds list is available <a href='https://www.ietf.org/timezones/data/leap-seconds.list' target='_blank'>here</a></div>\r\n");
        
    WebAddH2("Governor");
    WebAddAjaxInput      ("Ppb"                     , 5, "ajax-ppb"          , "ppb"           );
    WebAddAjaxInput      ("Ppb divisor"             , 5, "ajax-ppb-divisor"  , "ppbdivisor"    );
    WebAddAjaxInput      ("Ppb max change"          , 5, "ajax-ppb-max-chg"  , "ppbmaxchange"  );
    WebAddAjaxInput      ("Ppb synced limit"        , 5, "ajax-ppb-syn-lim"  , "syncedlimitppb");
    WebAddAjaxInput      ("Ppb synced hysteresis"   , 5, "ajax-ppb-syn-hys"  , "syncedhysppb"  );
    WebAddAjaxInput      ("Offset divisor"          , 5, "ajax-off-divisor"  , "slewdivisor"   );
    WebAddAjaxInput      ("Offset max (ms)"         , 5, "ajax-off-max"      , "slewmax"       );
    WebAddAjaxInput      ("Offset synced limit (ms)", 5, "ajax-off-syn-lim"  , "syncedlimitns" );
    WebAddAjaxInput      ("Offset synced hys (ms)"  , 5, "ajax-off-syn-hys"  , "syncedhysns"   );
    WebAddAjaxInput      ("Offset reset limit (s)"  , 5, "ajax-off-rst-lim"  , "maxoffsetsecs" );
    WebAddAjaxInputToggle("Trace"                      , "ajax-gov-trace"    , "clockgovtrace" );

    WebAddH2("NTP");
    WebAddAjaxInput      ("Server url"              , 5, "ajax-ntp-server"   , "ntpserver"     );
    WebAddAjaxInput      ("Initial interval (s)"    , 5, "ajax-ntp-initial"  , "clockinitial"  );
    WebAddAjaxInput      ("Normal interval (m)"     , 5, "ajax-ntp-normal"   , "clocknormal"   );
    WebAddAjaxInput      ("Retry interval (s)"      , 5, "ajax-ntp-retry"    , "clockretry"    );
    WebAddAjaxInput      ("Offset (ms)"             , 5, "ajax-ntp-offset"   , "clockoffset"   );
    WebAddAjaxInput      ("Max delay (ms)"          , 5, "ajax-ntp-max-delay", "clockmaxdelay" );

    WebAddH2("Scan times");
    WebAddAjaxLabelled   ("Program cycles avg", "ajax-scan-avg");
    WebAddAjaxLabelled   ("Program cycles max", "ajax-scan-max");
    WebAddAjaxLabelled   ("Program cycles min", "ajax-scan-min");

    WebAddEnd();
}