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.

Diff: base/web-server-base.c

Revision:
120:85a4d8f7517d
Parent:
110:8ab752842d25
Child:
132:5b2df69a4f17
--- a/base/web-server-base.c	Thu May 09 07:48:03 2019 +0000
+++ b/base/web-server-base.c	Thu May 09 09:38:42 2019 +0000
@@ -19,7 +19,7 @@
 #define DO_TRACE_AJAX      DO_BASE + 15
 #define DO_TRACE_SCRIPT    DO_BASE + 16
 #define DO_LOG_HTML        DO_BASE + 17
-#define DO_FAULT_HTML      DO_BASE + 18
+#define DO_RESET_HTML      DO_BASE + 18
 #define DO_FIRMWARE_HTML   DO_BASE + 19
 #define DO_FIRMWARE_AJAX   DO_BASE + 20
 #define DO_FIRMWARE_SCRIPT DO_BASE + 21
@@ -36,7 +36,7 @@
     if (HttpSameStr(pPath, "/log"          )) return DO_LOG_HTML;
     if (HttpSameStr(pPath, "/trace"        )) return DO_TRACE_HTML;
     if (HttpSameStr(pPath, "/trace-ajax"   )) return DO_TRACE_AJAX;
-    if (HttpSameStr(pPath, "/fault"        )) return DO_FAULT_HTML;
+    if (HttpSameStr(pPath, "/reset"        )) return DO_RESET_HTML;
     if (HttpSameStr(pPath, "/firmware"     )) return DO_FIRMWARE_HTML;
     if (HttpSameStr(pPath, "/firmware-ajax")) return DO_FIRMWARE_AJAX;
     
@@ -60,7 +60,7 @@
         case DO_CLOCK_AJAX:    WebClockQuery   (pQuery); return true;
         case DO_CLOCK_HTML:    WebClockQuery   (pQuery); return true;
         case DO_LOG_HTML:      WebLogQuery     (pQuery); return true;
-        case DO_FAULT_HTML:    WebFaultQuery   (pQuery); return true;
+        case DO_RESET_HTML:    WebResetQuery   (pQuery); return true;
         case DO_FIRMWARE_HTML: WebFirmwareQuery(pQuery); return true;
         case DO_FIRMWARE_AJAX: WebFirmwareQuery(pQuery); return true;
     }
@@ -95,7 +95,7 @@
         case DO_NET6_AJAX:       WebNet6Ajax      (); return true;
         case DO_NET6_SCRIPT:     WebNet6Script    (); return true;
         case DO_LOG_HTML:        WebLogHtml       (); return true;
-        case DO_FAULT_HTML:      WebFaultHtml     (); return true;
+        case DO_RESET_HTML:      WebResetHtml     (); return true;
         case DO_FIRMWARE_HTML:   WebFirmwareHtml  (); return true;
         case DO_FIRMWARE_AJAX:   WebFirmwareAjax  (); return true;
         case DO_FIRMWARE_SCRIPT: WebFirmwareScript(); return true;