April 01, 2014
The IETF's Security Area post-NSA - what is the systemic problem?
In the light of yesterday's newly revealed attack by the NSA on Internet standards, what are the systemic problems here, if any?
I think we can question the way the IETF is approaching security. It has taken a lot of thinking on my part to identify the flaw(s), and not a few rants, with many and aggressive defences and counterattacks from defenders of the faith. Where I am thinking today is this:
First the good news. The IETF's Working Group concept is far better at developing general standards than anything we've seen so far (by this I mean ISO, national committees, industry cartels and whathaveyou). However, it still suffers from two shortfalls.
1. the Working Group system is more or less easily captured by the players with the largest budget. If one views standards as the property of the largest players, then this is not a problem. If OTOH one views the Internet as a shared resource of billions, designed to serve those billions back for their efforts, the WG method is a recipe for disenfranchisement. Perhaps apropos, spotted on the TLS list by Peter Gutmann:
Documenting use cases is an unnecessary distraction from doing actual work. You'll note that our charter does not say "enumerate applications that want to use TLS".
I think reasonable people can debate and disagree on the question of whether the WG model disenfranchises the users, because even though a a company can out-manouver the open Internet through sheer persistence and money, we can still see it happen. In this, IETF stands in violent sunlight compared to that travesty of mouldy dark closets, CABForum, which shut users out while industry insiders prepared the base documents in secrecy.
I'll take the IETF any day, except when...
2. the Working Group system is less able to defend itself from a byzantine attack. By this I mean the security concept of an attack from someone who doesn't follow the rules, and breaks them in ways meant to break your model and assumptions. We can suspect byzantium disclosures in the fingered ID:
The United States Department of Defense has requested a TLS mode which allows the use of longer public randomness values for use with high security level cipher suites like those specified in Suite B [I-D.rescorla-tls-suiteb]. The rationale for this as stated by DoD is that the public randomness for each side should be at least twice as long as the security level for cryptographic parity, which makes the 224 bits of randomness provided by the current TLS random values insufficient.
Assuming the story as told so far, the US DoD should have added "and our friends at the NSA asked us to do this so they could crack your infected TLS wide open in real time."
Such byzantine behaviour maybe isn't a problem when the industry players are for example subject to open observation, as best behaviour can be forced, and honesty at some level is necessary for long term reputation. But it likely is a problem where the attacker is accustomed to that other world: lies, deception, fraud, extortion or any of a number of other tricks which are the tools of trade of the spies.
Which points directly at the NSA. Spooks being spooks, every spy novel you've ever read will attest to the deception and rule breaking. So where is this a problem? Well, only in the one area where they are interested in: security.
Which is irony itself as security is the field where byzantine behaviour is our meat and drink. Would the Working Group concept past muster in an IETF security WG? Whether it does or no depends on whether you think it can defend against the byzantine attack. Likely it will pass-by-fiat because of the loyalty of those involved, I have been one of those WG stalwarts for a period, so I do see the dilemma. But in the cold hard light of sunlight, who is comfortable supporting a WG that is assisted by NSA employees who will apply all available SIGINT and HUMINT capabilities?
Can we agree or disagree on this? Is there room for reasonable debate amongst peers? I refer you now to these words:
On September 5, 2013, the New York Times [18], the Guardian [2] and ProPublica [12] reported the existence of a secret National Security Agency SIGINT Enabling Project with the mission to “actively [engage] the US and foreign IT industries to covertly influence and/or overtly leverage their commercial products’ designs.” The revealed source documents describe a US $250 million/year program designed to “make [systems] exploitable through SIGINT collection” by inserting vulnerabilities, collecting target network data, and influencing policies, standards and specifications for commercial public key technologies. Named targets include protocols for “TLS/SSL, https (e.g. webmail), SSH, encrypted chat, VPNs and encrypted VOIP.”
The documents also make specific reference to a set of pseudorandom number generator (PRNG) algorithms adopted as part of the National Institute of Standards and Technology (NIST) Special Publication 800-90 [17] in 2006, and also standardized as part of ISO 18031 [11]. These standards include an algorithm called the Dual Elliptic Curve Deterministic Random Bit Generator (Dual EC). As a result of these revelations, NIST reopened the public comment period for SP 800-90.
And as previously written here. The NSA has conducted a long term programme to breach the standards-based crypto of the net.
As evidence of this claim, we now have *two attacks*, being clear attempts to trash the security of TLS and freinds, and we have their own admission of intent to breach. In their own words. There is no shortage of circumstantial evidence that NSA people have pushed, steered, nudged the WGs to make bad decisions.
I therefore suggest we have the evidence to take to a jury. Obviously we won't be allowed to do that, so we have to do the next best thing: use our collective wisdom and make the call in the public court of Internet opinion.
My vote is -- guilty.
One single piece of evidence wasn't enough. Two was enough to believe, but alternate explanations sounded plausible to some. But we now have three solid bodies of evidence. Redundancy. Triangulation. Conclusion. Guilty.
Where it leaves us is in difficulties. We can try and avoid all this stuff by e.g., avoiding American crypto, but it is a bit broader that that. Yes, they attacked and broke some elements of American crypto (and you know what I'm expecting to fall next.). But they also broke the standards process, and that had even more effect on the world.
It has to be said that the IETF security area is now under a cloud. Not only do they need to analyse things back in time to see where it went wrong, but they also need some concept to stop it happening in the future.
The first step however is to actually see the clouds, and admit that rain might be coming soon. May the security AD live in interesting times, borrow my umbrella?
Posted by iang at April 1, 2014 11:56 PM | TrackBack