RFC 4121 & acceptor subkey use in MIC token generation

Ken Hornstein kenh at cmf.nrl.navy.mil
Fri Oct 27 21:15:25 EDT 2023


>Uh...  If someone was able to swing that then you should be able to
>swing use of MD5 for non-cryptographic purposes where a 20 year old RFC
>requires it.  But, I know, I know, never mind.

You are assuming someone is looking at all of the STIGs and they're all
logically consistent with each other.  I think the reality is that whomever
does the AAA STIG doesn't really look at or care about any of the others.

>IDEA: Patch ssh to support use of x.509 certificates.
>
>After all, you can't use OpenSSH certs because... that's not "the DoD
>PKI", and you can't use GSS-KEYEX because of the foregoing MD5
>non-issue, so might as well do the one thing you are allowed to do: use
>the DoD PKI!

Well, I _am_ allowed to use gssapi-with-mic (there's no rule against
it, e.g. the "Air Bud" loophole), and as you note everything seems to
support that, and honestly it seems to work completely fine.  I'm not
sure what having OpenSSH use X.509 certificates directly would get us,
other than a huge pile of code that wasn't compatible with anything
else.

>And you're using Heimdal, right?

Geez, you missed that part?  No, we are pretty much an MIT shop.  And
judging by what I've seen it seems like so most of the DoD (at least on
the Unix side of things).

--Ken


More information about the Kerberos mailing list