Re: [dane] Digest Algorithm Agility discussion
Viktor Dukhovni <viktor1dane@dukhovni.org> Mon, 17 March 2014 18:22 UTC
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Date: Mon, 17 Mar 2014 18:22:19 +0000
From: Viktor Dukhovni <viktor1dane@dukhovni.org>
To: dane@ietf.org
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References: <20140315051704.GY21390@mournblade.imrryr.org> <alpine.LFD.2.10.1403171115580.32251@bofh.nohats.ca> <20140317155049.GB24183@mournblade.imrryr.org> <B4473EDA-DAB4-4CC2-ACCD-B4F8939E5A2C@vpnc.org> <20140317174423.GE24183@mournblade.imrryr.org> <040FB71F-BD97-44A2-A600-B6E69FBD1EE5@vpnc.org>
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Subject: Re: [dane] Digest Algorithm Agility discussion
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On Mon, Mar 17, 2014 at 11:14:32AM -0700, Paul Hoffman wrote: > > There is no text in 6698 that even approximately suggests that clients > > get to use only the records with the strongest (local criteria) digest. > > In Section 4.1: > o A TLSA RRSet whose DNSSEC validation state is secure MUST be used > as a certificate association for TLS unless a local policy would > prohibit the use of the specific certificate association in the > secure TLSA RRSet. This is not "use strongest". This is the opposite. It forces the use of tarnished, but still acceptable digests even when untarnished digests are present. The new proposal is to ignore all but the strongest, even when the remainder would be usable. Also the pseudo-code in the appendices loops over *all* "usable" TLSA RRs (those not banned by 4.1). My proposal modifies the pseudo-code to loop over only those records (for each usage/selector) with the strongest digest plus any records with matching type 0. The key difference is the lifecycle of a tarnished digest. With 6698, it is trusted until the moment it is dropped. With the new proposal it gradually fades out. I think the fading out part is an important feature. It makes it possible to be secure with servers that publish strong RRs even while accepting weak digests from servers that don't. -- Viktor.
- [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Wouters
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Hoffman
- Re: [dane] Digest Algorithm Agility discussion Paul Wouters
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Hoffman
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Wouters
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Hoffman
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Martin Rex
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion (c… Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Jim Schaad
- Re: [dane] Digest Algorithm Agility discussion (c… Paul Hoffman
- Re: [dane] Digest Algorithm Agility discussion (c… Andrew Sullivan
- Re: [dane] Digest Algorithm Agility discussion (c… Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion (c… Scott Rose
- Re: [dane] Digest Algorithm Agility discussion (c… Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion (c… Scott Rose
- Re: [dane] Digest Algorithm Agility discussion Wes Hardaker
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Peter Palfrader
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Peter Palfrader
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Peter Palfrader
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Wouters
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Peter Palfrader
- Re: [dane] Digest Algorithm Agility discussion Wes Hardaker
- Re: [dane] Digest Algorithm Agility discussion Wes Hardaker