Re: [saag] [Cfrg] Further MD5 breaks: Creating a rogue CAcertificate
"Santosh Chokhani" <SChokhani@cygnacom.com> Thu, 01 January 2009 17:01 UTC
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Thread-Topic: [Cfrg] [saag] Further MD5 breaks: Creating a rogue CAcertificate
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References: <495BA5E9.8040305@pobox.com><E1LILYj-00066V-WE@wintermute01.cs.auckland.ac.nz> <1b587cab0901010706j6e8cd2f8pf23345660a4825a5@mail.gmail.com>
From: Santosh Chokhani <SChokhani@cygnacom.com>
To: Ben Laurie <benl@google.com>, Peter Gutmann <pgut001@cs.auckland.ac.nz>
Cc: ietf-pkix@imc.org, mike-list@pobox.com, cfrg@irtf.org, saag@ietf.org, ietf-smime@imc.org
Subject: Re: [saag] [Cfrg] Further MD5 breaks: Creating a rogue CAcertificate
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Changing the order of extensions does not change their meaning. Actually, a CA could put the extensions in random order for various certificates. The attack will still work if the certificate size does not change. -----Original Message----- From: cfrg-bounces@irtf.org [mailto:cfrg-bounces@irtf.org] On Behalf Of Ben Laurie Sent: Thursday, January 01, 2009 10:06 AM To: Peter Gutmann Cc: ietf-pkix@imc.org; mike-list@pobox.com; cfrg@irtf.org; saag@ietf.org; ietf-smime@imc.org Subject: Re: [Cfrg] [saag] Further MD5 breaks: Creating a rogue CAcertificate On Thu, Jan 1, 2009 at 11:17 AM, Peter Gutmann <pgut001@cs.auckland.ac.nz> wrote: > > Mike <mike-list@pobox.com> writes: > >There is a simple fix -- a CA can just reorder the extensions prior to > >issuing a certificate. > > That's actually a nice fix, but unfortunately not universally applicable: for > some types of signed data (e.g. S/MIME attributes) the DER rules require > sorting the encoded extensions, so there's only one valid order for them (and > some applications actually check for this, so you have to do it or sig checks > will start failing). Surely the whole point of DER is that there's only one correct way to encode any particular certificate? So, either extensions must be sorted, or changing their order changes their meaning. Either way, nothing can be reordered. _______________________________________________ Cfrg mailing list Cfrg@irtf.org https://www.irtf.org/mailman/listinfo/cfrg _______________________________________________ saag mailing list saag@ietf.org https://www.ietf.org/mailman/listinfo/saag
- [saag] Further MD5 breaks: Creating a rogue CA ce… Russ Housley
- Re: [saag] Further MD5 breaks: Creating a rogue C… Jeffrey Hutzelman
- Re: [saag] Further MD5 breaks: Creating a rogue C… Eric Rescorla
- Re: [saag] Further MD5 breaks: Creating a rogue C… Russ Housley
- Re: [saag] Further MD5 breaks: Creating a rogue C… Paul Hoffman
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Eric Rescorla
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Jeffrey Hutzelman
- Re: [saag] Further MD5 breaks: Creating a rogue C… Russ Housley
- Re: [saag] Further MD5 breaks: Creating a rogue C… Yoav Nir
- Re: [saag] Further MD5 breaks: Creating a rogue C… Russ Housley
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Eric Rescorla
- Re: [saag] Further MD5 breaks: Creating a rogue C… Russ Housley
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Eric Rescorla
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Nicolas Williams
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Jeffrey Hutzelman
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] Further MD5 breaks: Creating a rogue C… Santosh Chokhani
- Re: [saag] Further MD5 breaks: Creating a rogue C… Santosh Chokhani
- Re: [saag] Further MD5 breaks: Creating a rogue C… Santosh Chokhani
- Re: [saag] Further MD5 breaks: Creating a rogue C… Hugo Krawczyk
- Re: [saag] Further MD5 breaks: Creating a rogue C… Jeffrey Hutzelman
- Re: [saag] Further MD5 breaks: Creating a rogue C… Peter Gutmann
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Eric Rescorla
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] Further MD5 breaks: Creating a rogue C… RJ Atkinson
- Re: [saag] Further MD5 breaks: Creating a rogue C… Santosh Chokhani
- Re: [saag] Further MD5 breaks: Creating a rogue C… Vishwas Manral
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … RJ Atkinson
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Peter Gutmann
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Peter Gutmann
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Ben Laurie
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Eric Rescorla
- Re: [saag] RFC analyzing IETF use of hash functio… Sean Shen
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Paul Hoffman
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Ben Laurie
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Ben Laurie
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Robert Moskowitz
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Sean Shen
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Yoav Nir
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Paul Hoffman
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Yoav Nir
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Peter Gutmann
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Paul Hoffman
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Jeffrey Hutzelman
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Santosh Chokhani
- Re: [saag] Further MD5 breaks: Creating a rogue C… RL 'Bob' Morgan
- Re: [saag] Further MD5 breaks: Creating a rogue C… Peter Hesse
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Blake Ramsdell
- Re: [saag] Further MD5 breaks: Creating a rogue C… Scott Rea
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] Further MD5 breaks: Creating a rogue C… Timothy J. Miller
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Tim Moses
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Mike
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Richard Graveman
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Mike
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Dr Stephen Henson
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] Further MD5 breaks: Creating a rogue C… Philipp Guehring
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Mike
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Peter Hesse
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Weger, B.M.M. de
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Yoav Nir
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Yoav Nir
- Re: [saag] Further MD5 breaks: Creating a rogue C… der Mouse
- Re: [saag] Further MD5 breaks: Creating a rogue C… RJ Atkinson
- [saag] attacks on keyed-hash constructions [was: … David McGrew
- Re: [saag] attacks on keyed-hash constructions [w… RJ Atkinson
- [saag] RFC analyzing IETF use of hash functions [… David McGrew
- Re: [saag] [Cfrg] RFC analyzing IETF use of hash … Paul Hoffman
- Re: [saag] Further MD5 breaks: Creating a rogue C… Jeffrey Hutzelman
- Re: [saag] [Cfrg] RFC analyzing IETF use of hash … Vishwas Manral
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Stephen Kent
- Re: [saag] RFC analyzing IETF use of hash functio… Sean Turner
- Re: [saag] RFC analyzing IETF use of hash functio… David McGrew
- Re: [saag] [Cfrg] RFC analyzing IETF use of hash … David McGrew
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] [Cfrg] attacks on keyed-hash construct… Christian Rechberger
- Re: [saag] [Cfrg] RFC analyzing IETF use of hash … Ran Canetti
- Re: [saag] [Cfrg] Further MD5 breaks: Creating a … Timothy J. Miller
- Re: [saag] [Cfrg] RFC analyzing IETF use of hash … David McGrew
- Re: [saag] [Cfrg] RFC analyzing IETF use of hash … Joseph Salowey (jsalowey)