rothwell.im

by Jonathan Rothwell

Goodbye, WordPress posts

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After over of two years of concurrent websites, one hosted with lovely static Octopress and the other with the lovely dynamic WordPress, a few nights ago I shut down the MySQL instance hosting the old notroswell.com website.

I’ve looked at various migration strategies, but would not be comfortable with implementing any until I have moved this site to the incoming Octopress 3.0. This will break links, for which I can only apologise—it was simply no longer viable, nor sensible, to be paying for the hosting an increasingly-vulnerable PHP application as well as the ‘new’ site.

I still hope to move some posts in the future, but for now, the old posts from notroswell.com will only exist where cached or archived elsewhere on the Web. The old URL now points here.

[LINK] Downtime post-mortem

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If you tried to access this site around this time last week, you’ll have been greeted with this error message:

The web host have a good write up of the incident, caused by a hardware failure following the file server being kicked.

The good news is that the hardware is on order to get these single points of failure out of their infrastructure. I’m also looking at alternates for situations like this myself, although naturally I can’t promise anything—the site is hosted at my own expense, so I can’t exactly justify splashing out on an intricate failover system.

[LINK] Realtime Trains for iPhone

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I’ve been helping with the testing process for Realtime Trains for iOS for the last few months, and the level of fit and finish in the final product is superb. I’ve certainly found the predictions to be much more accurate than National Rail Enquiries’ own application—and the ‘approaching/arriving/here’ indicator is a godsend for me, because I now know when to run in the evenings!

Goto FAIL: the aftermath

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The huge TLS/SSL bug in OS X has finally been patched in OS X 10.9.2. The fix was about four days too late (seriously, would fixing a single line of code and re-issuing it as a delta 10.9.1.1 update have been too hard?) but as always, it’s better late than never. (Naturally, if you’re a Mac user on Mavericks, or an iOS user on 7.0.5 or earlier, you should update your machine now.)

Many words have been said about the bug itself, unearthed in Apple’s TLS stack. Many have (unfairly) blamed the goto command, which is slightly suspect: one could easily have allowed a similar bug to creep in using functional calls and return values. (I’m not sure I agree with the use of goto in this particular case, but it’s not the cause of the problem.) Others have suggested that, had the programmer been conditioned to hit ^I (in Xcode, or ⌘⇧F, had they been using Eclipse or a similar IDE) before pushing, they might’ve spotted the bug, or at least increased the chance it might’ve been picked up during a code review.

Judging by the diff (mirrored on GitHub), it looks unlikely that the duplication of the goto fail happened as a result of a merge conflict.1 It would also be astonishing if Apple didn’t have any unit test coverage on such an important part of the security stack, or at least a vigorous code review process. Code review doesn’t always work: sometimes the programmers reviewing the code are overworked, tired, distracted, drunk, etc., much like the programmers who wrote the code.

An interesting theory was posited on Daring Fireball: the bug first appeared in iOS 6, which was released a short time before iOS was ‘added’ to the NSA’s PRISM programme. I still think that it is unlikely Apple (or any large technology company) would agree to build in a backdoor at the beck and call of an espionage agency. The chain of people that would need to agree to such a thing (and also be sworn to silence), from managerial positions right down to the developer who commits the code, is just too long; furthermore, it also assumes that all executives of all companies are easily bribable micromanagers with fine control over their codebase, with no moral compass whatsoever and in cahoots with the Pentagon/Fort Meade. One person is easier to bribe or plant than a whole chain.

So, the way I see it, there are three possibilities:

  1. The goto fail bug was introduced by accident and is a bona fide software defect. Apple has no automatic testing on this stack (or the test suite is incomplete, or it’s ignored when it fails.) Therefore Apple’s software development policies are shocking. The NSA has better auto-testing than Apple, picked up this defect and (probably) exploited it.
  2. The goto fail bug was introduced by accident and is a bona fide software defect. Apple did have automatic testing on this stack, but a programmer (probably a junior programmer, or an inexperienced QA engineer or test monkey) couldn’t work out why the test for SSLVerifySignedServerKeyExchange was failing, and so set it to be ignored or deleted it. This is extremely bad practice, but I can believe it happened. The NSA picked up this defect and (probably) exploited it.
  3. The goto fail bug was a backdoor deliberately inserted by someone (a planted Apple employee or a contractor) in the pay of a third party. This person also snaffled the automatic test coverage at the same time. No-one noticed, or bothered to question, why this code was removed.

Of course, we’ll likely never know the exact reason why this bug slipped through the net. But there are lessons to be reminded of from the whole sorry affair anyway: patches for critical defects must be issued immediately, and auditing and auto testing is important!

  1. This assumes, of course, that there was only one programmer working on this file for iOS 6/OS X 10.9 and there were no internal (i.e. between Apple employees’ repos) merge conflicts in the interim.↩

[LINK] Smart devices on the internet of things a disaster waiting to happen

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Missed this the first time round, but here’s Peter Bright at Ars discussing the disaster waiting to happen when your manufacturer drops support for your smart fridge.

Our fridges, cars, and TVs are not even on a two-year replacement cycle. Even if you do replace your TV after it's a couple years old, you probably won't throw the old one away. It will just migrate from the living room to the master bedroom, and then from the master bedroom to the kids' room. Likewise, it's rare that a three-year-old car is simply consigned to the scrap heap. It's given away or sold off for a second, third, or fourth "life" as someone else's primary vehicle. Your fridge and washing machine will probably be kept until they blow up or you move houses.

Even Microsoft have been known to drop support for platforms leaving customers out in the dark (I know this from experience, having tried to activate a GfWL copy of Halo 2)—so it’s impossible to see how companies like Samsung, or, god forbid, Electrolux or Russell Hobbs, will continue to provide updates for these smart devices of any kind.