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-script.js

Committer:
andrewboyson
Date:
2019-07-31
Revision:
127:bd6dd135009d
Parent:
115:24cb6e84ddd6
Child:
149:24365666d28d

File content as of revision 127:bd6dd135009d:

'use strict';

var file;
var xhr;

function logUpload(text)
{
    document.getElementById('uploadresult').textContent = text;
}
function xhrUploadResponse()
{
    var topics = xhr.responseText.split('\f');
    logUpload(topics[0]);
    if (topics.length > 1) document.getElementById('list').textContent = topics[1];
}
function xhrUploadOnLoad()
{
    if (xhr.status == 200) xhrUploadResponse();
    else                   logUpload('Upload failed');
}
function xhrUploadOnError()
{
    logUpload('Upload error');
}
function xhrUploadStart()
{
    logUpload('Uploading...');
    
    xhr = new XMLHttpRequest();

    xhr.onload  = xhrUploadOnLoad;
    xhr.onerror = xhrUploadOnError;

    xhr.open('POST', '/firmware-ajax'); //Defaults to async=true
    xhr.send(file);
}

function startUpload()
{
    var fileInput = document.getElementById('fileInput');

    if (fileInput.files.length == 0)
    {
        logUpload('Please choose a file');
        return;
    }

    if (fileInput.files.length > 1)
    {
        logUpload('Please choose just one file');
        return;
    }
    
    file = fileInput.files[0];
    
    xhrUploadStart();
}
function logRestart(text)
{
    document.getElementById('restartresult').textContent = text;
}
function redirect()
{
    location.href = '/firmware';
}
function xhrRestartOnLoad()
{
    if (xhr.status == 200) logRestart('Restart should never have returned');
    else                   logRestart('Restart failed');
}
function xhrRestartStart()
{
    logRestart('Restarting...');
    
    xhr = new XMLHttpRequest();

    xhr.onload  = xhrRestartOnLoad;

    xhr.open('GET', '/firmware-ajax?restart='); //Defaults to async=true
    xhr.send();
    
    setTimeout(redirect, 2000);
}
function restart()
{
    xhrRestartStart();
}