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/firmware/web-firmware-html.c@127:bd6dd135009d, 2019-07-31 (annotated)

Committer:
andrewboyson
Date:
Wed Jul 31 15:09:15 2019 +0000
Revision:
127:bd6dd135009d
Parent:
122:cd3f391ac8aa
Child:
158:80441390de93
Amalgamated Reply into Poll function

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 110:8ab752842d25 1 #include <stdio.h>
andrewboyson 110:8ab752842d25 2
andrewboyson 110:8ab752842d25 3 #include "http.h"
andrewboyson 110:8ab752842d25 4 #include "web-nav-base.h"
andrewboyson 110:8ab752842d25 5 #include "web-add.h"
andrewboyson 110:8ab752842d25 6 #include "web-firmware.h"
andrewboyson 110:8ab752842d25 7
andrewboyson 110:8ab752842d25 8 void WebFirmwareHtml()
andrewboyson 110:8ab752842d25 9 {
andrewboyson 110:8ab752842d25 10 HttpOk("text/html; charset=UTF-8", "no-cache", NULL, NULL);
andrewboyson 110:8ab752842d25 11 WebAddHeader("Firmware", "settings.css", "firmware.js");
andrewboyson 110:8ab752842d25 12 WebAddNav(FIRMWARE_PAGE);
andrewboyson 110:8ab752842d25 13 WebAddH1("Firmware");
andrewboyson 110:8ab752842d25 14
andrewboyson 110:8ab752842d25 15 WebAddH2("Existing files on the device");
andrewboyson 110:8ab752842d25 16
andrewboyson 110:8ab752842d25 17 HttpAddText("<code id='list'>");
andrewboyson 110:8ab752842d25 18 WebFirmwareListSemihostFiles();
andrewboyson 110:8ab752842d25 19 HttpAddText("</code>\r\n");
andrewboyson 110:8ab752842d25 20
andrewboyson 110:8ab752842d25 21 WebAddH2("Choose a local file");
andrewboyson 110:8ab752842d25 22 HttpAddText("<div><input type='file' id='fileInput'/></div>\r\n");
andrewboyson 110:8ab752842d25 23
andrewboyson 110:8ab752842d25 24 WebAddH2("Upload the local file to the device");
andrewboyson 110:8ab752842d25 25 HttpAddText("<div><button onclick='startUpload();'>Upload</button></div>\r\n");
andrewboyson 110:8ab752842d25 26 HttpAddText("<code id='uploadresult'></code>\r\n");
andrewboyson 110:8ab752842d25 27
andrewboyson 110:8ab752842d25 28 WebAddH2("Restart the device");
andrewboyson 110:8ab752842d25 29 HttpAddText("<div><button onclick='restart();'>Restart</button></div>\r\n");
andrewboyson 110:8ab752842d25 30 HttpAddText("<code id='restartresult'></code>\r\n");
andrewboyson 122:cd3f391ac8aa 31
andrewboyson 122:cd3f391ac8aa 32 WebAddEnd();
andrewboyson 110:8ab752842d25 33 }