Getting Blasted by Backdoors


Open Door from http://viktoria-lyn.deviantart.com/

I wanted to take minute to talk about a story I’ve been following that’s had some new developments this week. You may have seen an article talking about a backdoor in Juniper equipment that caused some issues. The issue at hand is complicated at the linked article does a good job of explaining some of the nuance. Here’s the short version:

  • The NSA develops a version of Dual EC random number generation that includes a pretty substantial flaw.
  • That flaw? If you know the pseudorandom value used to start the process you can figure out the values, which means you can decrypt any traffic that uses the algorithm.
  • NIST proposes the use of Dual EC and makes it a requirement for vendors to be included on future work. Don’t support this one? You don’t get to even be considered.
  • Vendors adopt the standard per the requirement but don’t make it the default for some pretty obvious reasons.
  • Netscreen, a part of Juniper, does use Dual EC as part of their default setup.
  • The Chinese APT 5 hacking group figures out the vulnerability and breaks into Juniper to add code to Netscreen’s OS.
  • They use their own seed value, which allows them to decrypt packets being encrypted through the firewall.
  • Hilarity does not ensue and we spend the better part of a decade figuring out what has happened.

That any of this even came to light is impressive considering the government agencies involved have stonewalled reporters and it took a probe from a US Senator, Ron Wyden, to get as far as we have in the investigation.

Protecting Your Platform

My readers know that I’m a pretty staunch advocate for not weakening encryption. Backdoors and “special” keys for organizations that claim they need them are a horrible idea. The safest lock is one that can’t be bypassed. The best secret is one that no one knows about. Likewise, the best encryption algorithms are ones that can’t be reversed or calculated by anyone other than the people using them to send messages.

I get that the flood of encrypted communications today is making life difficult for law enforcement agencies all over the world. It’s tempting to make it a requirement to allow them a special code that will decrypt messages to keep us safe and secure. That’s the messaging I see every time a politician wants to compel a security company to create a vulnerability in their software just for them. It’s all about being safe.

Once you create that special key you’ve already lost. As we saw above, the intentions of creating a backdoor into an OS so that we could spy on other people using it backfired spectacularly. Once someone else figured out that you could guess the values and decrypt the traffic they set about doing it for themselves. I can only imagine the surprise at the NSA when they realized that someone had changed the values in the OS and that, while they themselves were no longer able to spy with impunity, someone else could be decrypting their communications at that very moment. If you make a key for a lock someone will figure out how to make a copy. It’s that simple.

We focus so much on the responsible use of these backdoors that we miss the bigger picture. Sure, maybe we can make it extremely difficult for someone in law enforcement to get the information needed to access the backdoor in the name of national security. But what about other nations? What about actors not tied to a political process or bound by oversight from the populace. I’m more scared that someone that actively wishes to do me harm could find a way to exploit something that I was told had to be there for my own safety.

The Juniper story gets worse the more we read into it but they were only the unlucky dancer with a musical chair to slip into when the music stopped. Any one of the other companies that were compelled to include Dual EC by government order could have gotten the short straw here. It’s one thing to create a known-bad version of software and hope that someone installs it. It’s an entirely different matter to force people to include it. I’m honestly shocked the government didn’t try to mandate that it must be used exclusively of other algorithms. In some other timeline Cisco or Palo Alto or even Fortinet are having very bad days unwinding what happened.


Tom’s Take

The easiest way to avoid having your software exploited is not to create your own exploit for it. Bugs happen. Strange things occur in development. Even the most powerful algorithms must eventually yield to Moore’s Law or Shor’s Algorithm. Why accelerate the process by cutting a master key? Why weaken yourself on purpose by repeating over and over again that this is “for the greater good”? Remember that the greater good may not include people that want the best for you. If you’re wiling to hand them a key to unlock the chaos that we’re seeing in this case then you have overestimated your value to the process and become the very bad actor you hoped to stop.

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