It appears as though the carefully crafted hierarchy of trust that we’ve built in public key encryption is in danger of unraveling like a cheap suit. Thanks to DigiNotar, the heretofor unknown registrar for the government of the Netherlands, we’ve got ourselves another fake certificate floating around out there. This time, they generated a certificate for google.com (yes, the whole domain) back on July 19th. According to DigiNotar, their certification authority (CA) infrastructure was breached and used to generate the false certificate. Based on some defaced websites on DigiNotar’s site, there are strong rumors that a foreign government attempted to use the certificate as the catalyst in a man-in-the-middle (MITM) interception attack that would allow nefarious things like GMail to be snooped or search results to be cataloged.
Most security conscious users are already doing the smart thing. They are removing DigiNotar from their trust lists even as Microsoft, Mozilla, and Google remove the rogue certificate. I’m in the camp of completely removing DigiNotar from my list of trusted CAs. I’ve also done the same with Comodo after their little issue with rogue certificate problems a few months ago. To me, once a CA starts issuing false certificates, they have effectively erased any kind of trust they might have once built up. Even worse, by admitting that it was a security breach and not an honest mistake on the part of a careless employee or an admin with a grudge they have moved from the realm of carelessness and into the ocean of stupidity. If the CAs that sign our most trusted pieces of information that identify trustworthy organizations can be so easily compromised, how are we to trust the information we are presented? Granted, this kind of MITM does require a chokepoint, such as a country with only one or two regulated Internet terminus points. The risk of something similar happening in a country like the US or the UK is reduced due to our infrastructure, but it’s still something that could cause problems should a certificate like this be issued and then installed by a large ISP.
At Cisco Live, the 15,000 attendees hammered the Interop block providing Internet access to the point where the BGP peerings started freaking out. Some of our traffic was getting rerouted to Japan. A few noticed the strange google.co.jp pages popping up but thought nothing of them. That same mentality causes people to click through certificates without much thought to where they were issued from or whether or not they should be trusted. Now, compound that with a trusted provider not causing a certificate warning and you’ve got a recipe for disaster.
I think we need to take a hard look at all of these trusted CAs that are issuing certificates like I hand out candy at Halloween. Someone needs to provide real oversight and not just allow anyone to start signing identities. If you get caught issuing bad certificates, you should be shut down until you can prove you have implemented strict security measures somewhere other than on paper. If not, you get shut down and all your certificates get invalidated permanently. It would suck mightily, especially for a CA that signs government certificates. However, faced with the alternative, I think a little bit of trouble in rooting out the bad CAs is worth not having to face what could happen.
If you haven’t already, rip DigiNotar out of your trusted certificate list. Just search for your particular OS and there are lots of instructions. Update your browser, as all the major players have already removed the rogue certificate. Show DigiNotar that the price of being compromised is high. Maybe a few people protesting like this is equal to a bucket of water missing from the Pacific Ocean, but the more people that remove that trusted certificate, the bigger the message that can be sent to all these “trusted” companies that they had better keep the keys to their kingdom safe and sound. The alternative is a situation that doesn’t sit well with me at all.
Great article, Tom. I agree…PKI accountability shouldn’t be taken lightly. And sadly, most users will accept certificates blindly, so I have a feeling the effect will be a “bucket missing from the Pacific”. I, however, have removed Diginotar.