Randy,
The suggested mandate was for a cryptographically secure hash, which is
satisfied by either SHA256 or SHA512. Otherwise, collisions will reduce
the utility of Configuration State.
dhw
David H. Whitehead
Development Engineer
Lexmark International, Inc.
859.825.4914
davidatlexmarkdotcom
Randy Turner <rturner at amalfisystems.com>
08/15/08 02:13 PM
To
Dave Whitehead <david at lexmark.com>
cc
ids at pwg.org
Subject
Re: IDS> DRAFT: IETF NEA proposal
Hi Dave,
In the proposal, I just indicated that the "value" is a hash - it's
currently 32 bytes which only allows for a 256-bit hash. If we mandate
that it should be able
to hold a SHA-512 as well, we'll have to double it's length. I think just
getting agreement for the existence of the attribute is the goal, we can
flex the size of the
field once we have consensus on the acceptance of the attribute.
I agree with your comment about which values to include in the hash, but
from a protocol perspective, the mechanisms would work pretty much the
same way.
Even though a vendor could allow customers to indicate which parameters
are included in the hash, the "management tool in the sky" would have to
know which
parameters make up the hash, on a per-device basis, in order to
potentially remediate the situation. Given this constraint, I think
vendors should supply a factory
default set of params that make up the hash, a set that makes sense in the
majority of cases, and allow customers to override this, provided they
"sync up" their
remediation infrastructure with the same info...
Randy
On Aug 15, 2008, at 10:31 AM, Dave Whitehead wrote:
Randy,
Looks good. Two comments about Configuration State:
1> We should mandate the use of a cryptographically secure hash function
(SHA256/512)
2> Vendors provide the set of available configuration items but the
customer selects which items to include in the hash -- some they care
about, some they don't.
David H. Whitehead
Development Engineer
Lexmark International, Inc.
859.825.4914
davidatlexmarkdotcom
Randy Turner <rturner at amalfisystems.com
Sent by: owner-ids at pwg.org
08/15/08 04:02 AM
To
ids at pwg.org
cc
Subject
IDS> DRAFT: IETF NEA proposal
Hi All,
Please read the attached RTF and provide any feedback you may have...
Please excuse the VERY simple, raw formatting I'm using - this has to be
in the simplest ASCII text form possible for eventual emailing to the
NEA
mailing list.
For now, just concentrate on the content :) :)
Thanks!
Randy
[attachment "draft-nea-proposal.rtf" deleted by Dave
Whitehead/Lex/Lexmark]
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