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

Dependents:   heating gps

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.

Revision:
119:794e5985d6c8
Parent:
118:53430a2a2595
--- a/web-add.h	Wed May 08 12:14:13 2019 +0000
+++ b/web-add.h	Thu May 09 07:48:03 2019 +0000
@@ -1,30 +1,30 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-extern void WebAddNavItem      (int highlight, char* href, char* title);
+extern void WebAddNavItem      (int highlight, const char* href, const char* title);
 extern void WebAddNav          (int page);
 extern void WebAddHeader       (const char* title, const char* style, const char* script);
 extern void WebAddH1           (const char* pageName);
 extern void WebAddH2           (const char* text);
 extern void WebAddEnd          (void);
 
-extern void WebAddLabelledText        (char* label,                     char* text);
-extern void WebAddLabelledPrefixSuffix(char* label,   char* prefix,     char* text,  char* suffix);
-extern void WebAddLabelledMac         (char* label,                     char*   mac);
-extern void WebAddLabelledIp4         (char* label,                     uint32_t ip);
-extern void WebAddLabelledIp6         (char* label,                     char*    ip);
-extern void WebAddLabelledOnOff       (char* label,                     bool  value);
-extern void WebAddLabelledLed         (char* label,                     bool  value);
-extern void WebAddLabelledInt         (char* label,                     int   value);
+extern void WebAddLabelledText        (const char* label,                       const char* text);
+extern void WebAddLabelledPrefixSuffix(const char* label,   const char* prefix, const char* text,  const char* suffix);
+extern void WebAddLabelledMac         (const char* label,                       const char*   mac);
+extern void WebAddLabelledIp4         (const char* label,                       uint32_t       ip);
+extern void WebAddLabelledIp6         (const char* label,                       const char*    ip);
+extern void WebAddLabelledOnOff       (const char* label,                       bool        value);
+extern void WebAddLabelledLed         (const char* label,                       bool        value);
+extern void WebAddLabelledInt         (const char* label,                       int         value);
 
-extern void WebAddInputText           (char* label,   float inputwidth, char* value, char* action, char* name);
-extern void WebAddInputInt            (char* label,   float inputwidth, int   value, char* action, char* name);
-extern void WebAddInputButton         (char* label,                     char* value, char* action, char* name);
+extern void WebAddInputText           (const char* label,   float inputwidth,   const char* value, const char* action, const char* name);
+extern void WebAddInputInt            (const char* label,   float inputwidth,   int         value, const char* action, const char* name);
+extern void WebAddInputButton         (const char* label,                       const char* value, const char* action, const char* name);
 
-extern void WebAddAjaxLed             (char* label,                     char* id);
-extern void WebAddAjaxLabelled        (char* label,                     char* id);
-extern void WebAddAjaxLabelledSuffix  (char* label,                     char* id, char* suffix);
-extern void WebAddAjaxInputToggle     (char* label,                     char* id, char* name);
-extern void WebAddAjaxInput           (char* label,   float inputwidth, char* id, char* name);
-extern void WebAddAjaxInputSuffix     (char* label,   float inputwidth, char* id, char* name, char* suffix);
-extern void WebAddAjaxInputLabelId    (char* labelId, float inputwidth, char* id, char* name);
+extern void WebAddAjaxLed             (const char* label,                       const char* id);
+extern void WebAddAjaxLabelled        (const char* label,                       const char* id);
+extern void WebAddAjaxLabelledSuffix  (const char* label,                       const char* id,                   const char* suffix);
+extern void WebAddAjaxInputToggle     (const char* label,                       const char* id, const char* name);
+extern void WebAddAjaxInput           (const char* label,   float inputwidth,   const char* id, const char* name);
+extern void WebAddAjaxInputSuffix     (const char* label,   float inputwidth,   const char* id, const char* name, const char* suffix);
+extern void WebAddAjaxInputLabelId    (const char* labelId, float inputwidth,   const char* id, const char* name);