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.

log/http-log-query.c@34:30124e188ae1, 2019-01-18 (annotated)

Committer:
andrewboyson
Date:
Fri Jan 18 17:41:44 2019 +0000
Revision:
34:30124e188ae1
Parent:
33:68406cbde3e1
Child:
87:c51478679090
Updated net library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 0:f8998d10763e 1 #include "http.h"
andrewboyson 0:f8998d10763e 2 #include "log.h"
andrewboyson 0:f8998d10763e 3
andrewboyson 14:c3c43c8faf0e 4 void HttpLogQuery(char* pQuery)
andrewboyson 0:f8998d10763e 5 {
andrewboyson 0:f8998d10763e 6 while (pQuery)
andrewboyson 0:f8998d10763e 7 {
andrewboyson 0:f8998d10763e 8 char* pName;
andrewboyson 0:f8998d10763e 9 char* pValue;
andrewboyson 34:30124e188ae1 10 pQuery = HttpQuerySplit(pQuery, &pName, &pValue);
andrewboyson 33:68406cbde3e1 11 if (HttpSameStr(pName, "clearlog")) LogClear();
andrewboyson 0:f8998d10763e 12 }
andrewboyson 0:f8998d10763e 13 }