Re: [Acme] Considerations about ACME BoF

[Leif Johansson <[e-mail]>]

On 03/27/2015 03:32 PM, Massimiliano Pala wrote:
> Dear ACME BoF-ers,
> 
> when I started to write this e-mail I did not expect to get this long -
> since the content might be a bit controversial, I would encourage people
> to stick to the technical arguments and not start a flame war about the
> topics (that happened in the past.. many, many, many times...).

Hi Max,

I found myself disagreeing with just about everything you said below...

> 
> After attending the BoF and speaking with several people, I feel
> compelled to bring to the community's attention some concerns about
> ACME. I have two different types of concerns - procedural (and this
> might require a broader audience, probably a cross post to the ietf ml),
> and technical. I would like people commenting on both.
> 
> I think that ALL of the following points should be addresses before any
> decision about forming a new WG or even adopting the proposed I-D as a
> working item is taken.
> 
> Here's my concerns.
> 
> _*Procedural Issues.*_
> 
> *Let's Encrypt.* When the "Let's Encrypt" initiative was presented, I
> was quite confused about the scope. We all agree that IETF is about
> defining protocols on the wire - not promoting specific products or
> business models. However, in this case, I was under the impression that
> the IETF was sponsoring a specific piece of software and a new CA
> initiative that will be soon operational. Besides the fact that the new
> Let's Encrypt CA might (maybe not now) be a commercial viable
> initiative, my question is: why a non-existing, commercially viable,
> non-standard-based initiative is being presented at the IETF ? This is
> really troublesome especially in the view of this creating a precedence.
> What happens when another vendor comes to IETF and presents similar
> pitches about their products - what basis do we have to deny that
> presentation anymore ? This, I think, it is a really important point
> that should be discussed deeply.
> 


What do you mean "when"? It happens all the time in the IETF. In fact
when the IETF tries to do design (rather than build on existing work)
we often turn out camels.

Personally I don't give a hoot about who comes up with an idea if it is
a good one and letsencrypt has come up with a few good ones.

> *Overstepping the Technical Boundaries.* As it was pointed out during
> the BoF, the proposed initiative does not address any technical issue,
> but, instead, is pushing a specific BUSINESS model. I found very
> inappropriate the examples of "I could not get my certificates in 45
> minutes.." as this is a NON argument. Besides the many issues about an
> automated certificate issuance (even for just a DV cert), the choices
> made by current Internet CAs (I am referring to Internet CAs because for
> corporate or "closed" PKIs automation HAS NEVER BEEN A PROBLEM by using
> current standards) are based on POLICY decisions and not technical
> merits. Is IETF going to be in the policy decision business instead of
> focusing on technical aspects of interoperability?

Good engineering always takes business models into account. The problem
statement - "getting certificates takes too long and is too complex" -
is imo a valuable one and one that should be addressed as quickly as
possible.

> 
> *Real Scope of ACME.* I think there should be a discussion about where
> this work is supposed to land. If it is another attempt (as noted during
> the BoF) to push further DANE (even when, as pointed out during the BoF,
> there is not much real interest in the real world for it) possibly to
> replace work like WebPKI or PKIX protocols, this should be clearly
> stated. Also, if that is the case, I think we are potentially choosing a
> single-point-of-failure model for trust (DNSSEC) which is scary and
> dangerous especially from a privacy perspective considering who is in
> control of top-domain keys. Privacy advocates should really be concerned
> about this issue.

The argument that acme or letsencrypt is somehow "anti DANE" is
uninformed (and also wrong).

On the contrary, letsencrypt could use DANE TLSA records as DV proofs
which would drive deployment of DANE.

> 
> _*Technical Issues.*_
> 
> *Reinventing the Wheel.* During the meeting I already expressed my
> concerns about many different aspects of the proposed scope. First off,
> we have a serious problem with overlapping over EXISTING IETF standards
> for message formats that are perfectly viable and currently deployed in
> a lot of environments. I am referring to the CMC / CMS / EST. Lot of
> time and engineering efforts have been spent over these formats and tons
> of certificates are, today, managed using these formats. Moreover, these
> formats allow for deploying systems with multiple factors of
> authentication and hardware tokens. I should not have to explain to the
> IETF community the horrible mistake to have multiple competing standards
> (we went down that road in the past and it was A HORRIBLE DISASTER) -
> that is why, at each level of the IETF, much attention has been paid to
> avoid this situation. I do not see why this is an exception to this very
> important principle. If the work in the potential WG will continue, ARE
> WE GOING TO RETIRE EXISTING STANDARDS ?

Standards are only as useful as the problems they solve and the goals
they help us achieve.

If our goal is to increase the use of TLS by making it easier to obtain
certificates, then the current protocols for certificate life-cycle
management have not been very successful.

Re-inventing the wheel is sometimes the right thing to do - esp if you
manage to make wheel lighter and a bit more round.

> 
> *Message Format.* The argument about ASN.1 vs JSON has to be re-framed

Sigh.

	Cheers Leif