Re: [Isms] fingerprint TCs and hash types

[Juergen Schoenwaelder <j.schoenwaelder at jacobs-university.de>]

On Thu, Sep 10, 2009 at 10:48:55PM +0200, Wes Hardaker wrote:
 
> After doing research about what other fingerprinting / hash textual
> conventions were out there, I found none.  Which surprised me.  The end
> result was there was nothing to reuse, so we do need to define our own.
> 
> The -00 version of the document defines 2 TCs for "fingerprints"
> (FingerprintType and FingerprintValue).  These are worded generically so
> they can be reused elsewhere easily.

I am wondering what the correct term is here: fingerprint versus
(crptographic) hashvalue versus message digest. My understanding is
that FingerprintValue contains simply the output generated by the
hash function identified by FingerprintType, correct?
 
> The biggest question, as I was defining the TCs, was what type of data
> the FingerprintType should be.  Originally in the personal versions of
> the draft, it was an integer.  But it's highly likely that many other
> hashing algorithms will be defined in the future, especially with the
> NIST hashing algorithm "contest" going on right now.  So we certainly
> need something with agility.  In the end, I changed the FingerprintType
> to a OID instead.
> 
> Note that in our MIBs at least, it's not being used as an index so we
> don't have issues with the length restrictions it would impose on MIB
> objects.  I could easily see other MIBs wanting to put it in an INDEX
> though.

In SNMP-USER-BASED-SM-MIB, we have object identifies for
authentication and encryption protocols and the relevant columns of
the tables use SNMPv2-SMI's AutonomousType. Can we do the same? Is
FingerprintType as a separate TC really needed?

/js

PS: It would be nice if the hash algorithm OBJECT-IDENTITYs would
    have REFERENCE clauses.

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1, 28759 Bremen, Germany
Fax:   +49 421 200 3103         <http://www.jacobs-university.de/>