Older blog entries for mjcox (starting at number 87)

23 Nov 2002 (updated 23 Nov 2002 at 15:50 UTC) »

The months just fly by. I ended up spending a lot of time on the presentation and the final paper came in at about 40 pages. I'm pretty pleased with it, see my site for a PDF version. For some reason the paper was not included on the conference CD which really sucks considering I got it in before the deadline (and before some of the other papers that made it on to the CD). Anyway, it's on my site so take a look.

Just back from ApacheCon in Las Vegas; a little more budget than previous years, but all that matters is that the content is being delivered by experts right? Hmmm, well talking of which, I made a serious judgement error on the amount of material in my talk and ended up covering only 75% of what I put in the paper, which sucked. I'd spent a lot of time getting the presentation just right too, so it was a little devestating to find out I only had 30 minutes left with over half the material still to go.

We got some ASF keysigning going on, but the BOF was scheduled for 8am so some of the main ASF folks were not around to take part which was a shame.

We had a good time in Vegas, getting to see all the sights including the Star Trek Experience again, get out to Red Rock Canyon, and still have time to win about $40 on the slots.

Had a cold today so didn't get anything done on my presentation this evening, instead did something that required little work and hacked more Perl for the home automation system. There are now four jabber bots online, a common thread is that you can message them and get some status information, or send information to them to do, also if you've got them listed in your roster they'll send you an update with their status every minute.

At the moment the UPS bot tells you interesting status reports and notifies you of emergency things. The adsl bot tells you about the cable modem link signal strength and so on. The tivo bot is rather cool, it tells you what it's currently watching and a few status indicators, and in return you can pop up a message on the screen or send a message to be viewed in the message centre. The final X10 bot lets you control X10 things in the house, just some lights at the moment. It doesn't yet report the status, that seems not to work.

I'm having problems getting Perl to deal with the parallel ports correctly so I can't get the alarm, SMS or heating controls to work yet. Also these bots are complete hacks and return the information in psuedo-xml (random made up DTD) and I've not thought about messages vs groupchats vs iq oob for the data. Anyway much fun being able to message the living room lights to turn to 30% brightness

So I've been spending some time trying to work out what to do with the home automation components - they're a mess of C and Perl that have no real way of communicating with each other. I found this thing called xAP which is designed for home automation components to talk to each other, but it's based mainly on UDP broadcast datagrams - not something I'd trust to make sure things happened when my alarm was triggered. Plus some of the components already written are under a non-GPL, non-BSD license that prohibits commercial use, yuk.

Anyway the idea was to look for something that would use standard components, where frameworks existed in Perl and C for me to write simple code, and to work on the principle of messaging - the UPS for example would respond to status requests and give you things like the temperature and voltage; with a heartbeat notification with the status included every minute; but with urgent alarms to anyone who registers an interest in getting them. Whats the solution? Jabber! In about an hour I had a jabber server running and a test Perl client doing just that; this thing will rock :)

Suddenly realised that in the next month I have to write and prepare for 5 different presentations. I'm talking at ApacheCon in November and want to make the talk extra special, so I'll take a couple of days off in the next week or two to make sure it has some interesting content. "Apache Security Secrets Revealed" although I've no intention of hiding behind a mask until the end :)

I can't believe Bryce is leaving the US, he was one true friend who I really enjoyed spending time with when I was over in Raleigh - we'd always spend my spare weekends going shopping, driving around, or eating.

We were expecting someone to write an exploit for the OpenSSL issues (the problem is fairly straightforward to exploit as exploits go), well it started appearing with vengence in the wild on Friday 13th. Now everyone who didn't patch OpenSSL needs to run around like a headless chicken patching and making sure they didn't get exploited. Of course the only way to be certain you are not 0wn3d is to reinstall from scratch since loadable kernel module rootkits are pretty comprehensive these days. Quite a few folks were confused because they'd updated their Apache (but not their OpenSSL) and some others got exploited who upgraded but didn't reboot (or restart OpenSSL-based services) so never picked up the new OpenSSL shared libraries.

I put the baln S/PDIF idea on hold as it's getting cold now in Scotland; instead I spent a couple of evenings finishing off a heating controller. A PIC chip controlling a relay sit next to the central heating system connected across the thermostat inputs I wasn't using. The PIC is connected via the CAT5 network to my home automation PC. The PIC is designed to stop silly things happening if the computer dies in a bad state (heating on for 24 hours is bad) or if hackers get into the HA system. It makes sure you can't cycle between on and off too often and other stuff. Anyway now I need to write something to actually control it, and get some temperature sensors. Yeah, I could have gone and bought a $30 thermostat and wired that in instead, but it isn't as much fun and being able to turn on your heating whilst sitting in the living room on the wireless network.

Just say no to macerator pumps They place a large number of restrictions on what you can do with them (toilet paper only in the pan, no hairs down the sink, no cleaners), and then even when obeying all the instructions they fail to work, and when they fail to work you end up with a ton of waste soaking into your floor. This time spectacularly flooding (and ruining) the bathroom and hall floors and coming within inches of flooding the cupboard where my large UPS sits (stupidly) on the floor. A very large wet battery and invertor - that would have been a spectacular bang. So that put an end to the balun and S/PDIF (I got the acronym right this time) through CAT5 idea needing 3-400 pounds to fix the damages, and tommorrow a trip to the DIY store to buy some wood to raise the UPS by four inches or so and maybe some water sensor alarms, and possibly a bucket - low tech toilet, but at least it would work.

Who needs impossible-to-find-baluns anyway? I started looking back through my notes from years ago about using opamps to drive differential circuits, then had a quick google search which came up with this gem: http://www.elantec.com/pages/apppdf/d40968.pdf So for about $15 of components (RS Components even have them in stock) I can run SP/DIF through CAT5. Whee.

Spent a good few hours over the weekend trying to find misc bits and pieces to make my home automation more complete. I want to be able to play my music collection in the main room which has the nice 5.1 amp and speaker setup. I thought about buying an Audiotron or the cute spimmp3 devices, but they're about $300+VAT+duty+blah. So here is the alernative cunning plan:

  • Find a cheap soundcard that will output SP/DIF (coax) that works okay with Linux. SP/DIF input too would be nice but not essential. Not yet investigated.
  • Get a pair of 75 ohm to 110 ohm baluns. Then I can feed the SP/DIF output through the balun into the cat5 network, and up to the front room, converted again to SP/DIF and fed into the amp. How hard is it to find a UK source of these things, they should only be about $10-$20 each - it's only a transformer after all.
  • Find my awful IRDA keyboard that I bought in the USA for about $20 a couple of years ago instead of getting a IRDA receiver for the Linux machine.
Ideally I'd have a 2nd balun on the same cat5 cable passing composite video back from the machine through the AV amp to the TV, but that would mean sourcing a replacement video card that has composite out and works with Linux.

Backups, backups, backups. I do! I backup everything off-site! Well, okay, apart from my TiVo which I've not backed up for a while, since January in fact. So when the disk died yesterday and I was unable to salvage it enough to get a working backup off it and ended up with this really old backup, and having to do all the pain of resetting season passes, losing stored programs, losing tivoweb etc etc. Argh.

Still working on the technical review of this firewall book - going well but taking so long I wonder if I'd have time to write a book myself.

Nothing much changed on the house situation, I've brought in my legal insurance to take care of it now, they can have the hassle. A local company, Multipump services, are also becoming annoying as they refuse to return a repaired saniflow pump that I paid for them to repair back in April. Threatening legal action didn't help so I'll have to follow up and start small claims proceedings next week - they're messing me around on purpose and this thing is worth over 200 quid so I can't just ignore it.

More Apache fun last week with an advisory for security issues in 2.0.40 (fortunately which don't affect Unix machines).

Where did that month go? Well actually I know exactly where it went since I started managing my time using the Franklin Covey system. Security work keeps me busy and in spare time I've been finishing off our CVE mapping. I had a mad moment one evening and got our 2000 mapping nearly complete, so only a handful of issues left until we've got a 100% mapping.

In home life I now have the ability to assemble flat pack kitchen units with Italian instructions and make them defy gravity by fixing them to the garage walls using my new scary hammer action drill.

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