----- Original Message ----- From: "Stephen Farrell" <[email protected]> To: "The IESG" <[email protected]> Sent: Thursday, May 14, 2015 10:09 AM
> Stephen Farrell has entered the following ballot position for > draft-ietf-opsawg-hmac-sha-2-usm-snmp-06: Discuss > > The document, along with other ballot positions, can be found here: > https://datatracker.ietf.org/doc/draft-ietf-opsawg-hmac-sha-2-usm-snmp/ > > ---------------------------------------------------------------------- > DISCUSS: > ---------------------------------------------------------------------- > > Thanks for defining these. I do have a thing do briefly > discuss before balloting yes. I'll be getting out of your way > very shortly, but I want to check first to see if you agree > with me that this could be simpler and more useful. > > I note the following: > > - You're defining a bunch of HMAC options. > - Additional options for fun isn't a good idea with crypto. > - There may be platforms that do not have good APIs for > SHA224 or SHA384. > - HMAC-SHA256 without any truncation is considered perfectly > fine for this purpose and is widely used elsewhere. > - You don't need truncation for protocol reasons. > > To me, that implies that this would be better if it *only* > defined a non-truncated HMAC-SHA256 option and if all of the > rest were removed. > > Do you agree that doing so would achieve just as much of a > security improvement, but with less complexity for > implementation, test and interop? If so, should we just do > that? > Stephen, This was raised prior to adoption by OPSAWG, advice was sought and Uri Blumenthal said, 23 Sep 14 " I am for HMAC truncation. " and " There probably is no doubt that protocols based on SHA-256 and SHA-384 need to be there. SHA-512 might cause some raised brows, as could SHA-224. I still would add them - SHA-512 as SHOULD, and SHA-224 as MAY. " which convinced me to support the current position. (At one stage, the list was even longer:-). Tom Petch _______________________________________________ OPSAWG mailing list [email protected] https://www.ietf.org/mailman/listinfo/opsawg
