On Thu, Aug 15, 2019 at 08:14:12AM -0700, Mirja Kühlewind via Datatracker wrote: > Mirja Kühlewind has entered the following ballot position for > draft-ietf-tls-grease-03: No Objection > > When responding, please keep the subject line intact and reply to all > email addresses included in the To and CC lines. (Feel free to cut this > introductory paragraph, however.) > > > Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html > for more information about IESG DISCUSS and COMMENT positions. > > > The document, along with other ballot positions, can be found here: > https://datatracker.ietf.org/doc/draft-ietf-tls-grease/ > > > > ---------------------------------------------------------------------- > COMMENT: > ---------------------------------------------------------------------- > > One comment/question: I think I didn't quite understand what a client is > supposed to do if the connection fails with use of greasing values...? The > security considerations seems to indicate that you should not try to > re-connect > without use of grease but rather just fail completely...? Also should you > cache > the information that greasing failed maybe?
I'll let the authors chime in, but I think the sense of the security considerations is more that we are preventing the fallback from being needed "in production due to "real" negotiation failures. Falling back on GREASE failure is not as bad, provided that you follow-up with the failing peer out of band to try to get it fixed. I don't know how much value there would be in caching the grease-intolerate status; ideally it would almost-never happen. > And a note on normative language: > > "Implementations sending multiple > GREASE extensions in a single block thus must ensure the same value > is not selected twice." > Should this be a "MUST"? I asked for this to be changed away from a "MUST" -- RFC 8466 already has this prohibition on duplicated values; we're just calling it out again here since randomly picking values (with replacement, which is the easy way to code it) can result in collisions, that are forbidden by 8446. > Also this is an interesting MUST: > "... MUST correctly ignore unknown values..." > While this is the whole point of the document, I assume this is already > normatively specified in RFC8446 and therefore it could make sense to use > non-formative language here... I think you are correct, but I personally do not mind the extra normative force in this case. -Ben _______________________________________________ TLS mailing list TLS@ietf.org https://www.ietf.org/mailman/listinfo/tls
