Re: On the future of <keygen> and application/x-x509-*-cert MIME handling

On Thursday, 30 July 2015 01:35:49 UTC+2, David Keeler  wrote:
> [cc'd to dev-security for visibility. This discussion is intended to
> happen on dev-platform; please reply to that list.]
> 
> Ryan Sleevi recently announced the pre-intention to deprecate and
> eventually remove support for the <keygen> element and special-case
> handling of the application/x-x509-*-cert MIME types from the blink
> platform (i.e. Chrome).
> 
> Rather than reiterate his detailed analysis, I'll refer to the post here:
> 
> https://groups.google.com/a/chromium.org/d/msg/blink-dev/pX5NbX0Xack/kmHsyMGJZAMJ
> 
> Much, if not all, of that reasoning applies to gecko as well.
> Furthermore, it would be a considerable architectural improvement if
> gecko were to remove these features (particularly with respect to e10s).
> Additionally, if they were removed from blink, the compatibility impact
> of removing them from gecko would be lessened.
> 
> I therefore propose we follow suit and begin the process of deprecating
> and removing these features. The intention of this post is to begin a
> discussion to determine the feasibility of doing so.
> 
> Cheers,
> David

There is a lot of debate about this on various lists including an Agenda item Tim Berners Lee brought up on the subject at the TAG "<keygen> being destroyed when we need it"
https://lists.w3.org/Archives/Public/www-tag/2015Sep/thread.html

There were a lot of arguments on the blink forum but one key attack of keygen is that it is insecure because it uses MD5. I responded to that there, and put up a detailed explanation as to why that was not the case on the whatwg forum showing how the MD5 in the generated spkac is not important in the creation of the certificate, so the amazing attacks on certificate authorities demonstrated by Jacob Appelbaum and friends at the Chaos Communication Congress of 2008 do not apply here

   https://github.com/whatwg/html/issues/102

Finally all browsers even IE have something like keygen. IE just used JS tied to ActiveX for it, which sadly forces one to use both at present if one wants to work with IE.

https://msdn.microsoft.com/en-us/library/aa374863(VS.85).aspx

It would of course help if instead of having to split the conversation across N forums one could get together and work out these points one by one in the open. This is a complex topic, and it is all too easy to throw the baby out with the bath water  here.