Re: [saag] Improving the CHAP protocol
Yoav Nir <ynir.ietf@gmail.com> Sat, 21 September 2019 17:56 UTC
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From: Yoav Nir <ynir.ietf@gmail.com>
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Date: Sat, 21 Sep 2019 20:56:11 +0300
Cc: Maurizio Lombardi <mlombard@redhat.com>, Security Area Advisory Group <saag@ietf.org>
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References: <9641f69d-0ffb-1c1d-7fb6-98ef4a54ad2c@redhat.com> <1569087342890.52733@cs.auckland.ac.nz>
To: Peter Gutmann <pgut001@cs.auckland.ac.nz>
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Subject: Re: [saag] Improving the CHAP protocol
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FIPS is one advantage. The other is that MD5 is getting scarce in crypto libraries, while SHA-256 is everywhere. Not everything is devices — there’s still software out there. But yes, it’s still CHAP. > On 21 Sep 2019, at 20:35, Peter Gutmann <pgut001@cs.auckland.ac.nz> wrote: > > I think many people in this thread are missing the purpose of the exercise. > CHAP is used because umpteen bajillion devices and systems need it, not > because it's a very good protocol. It's insecure because it's CHAP, not > because it uses MD5. Since it needs a one-way function, not a collision- > resistant function, any hash function is as good - or bad since CHAP isn't > very secure - as any other. Switching from MD5 to polyquantumresistantind- > ccaprovable2048bithash will make no difference whatsoever to its security. > > What the original poster asked for is something FIPS compliant. If you want > to convince said umpteen bajillion devices to switch, you'd better use the > universal-standard FIPS-compliant hash algorithm that everything supports, > which is SHA-256, not a bunch of wierdo fashion-statement algorithms that > nothing supports, which is most of the other stuff that's been suggested. > > Having said that, you'll have to accept that the vast majority of users will > keep going with MD5 more or less forever since there's no motive apart from > FIPS to change, so perhaps it'd be best to pitch the update RFC as "FIPS > compliance for CHAP" or something similar. > > Peter. > > _______________________________________________ > saag mailing list > saag@ietf.org > https://www.ietf.org/mailman/listinfo/saag
- [saag] Improving the CHAP protocol Maurizio Lombardi
- Re: [saag] Improving the CHAP protocol Mark D. Baushke
- Re: [saag] Improving the CHAP protocol Kathleen Moriarty
- Re: [saag] Improving the CHAP protocol Black, David
- Re: [saag] Improving the CHAP protocol Kathleen Moriarty
- Re: [saag] Improving the CHAP protocol Peter Gutmann
- Re: [saag] Improving the CHAP protocol Yoav Nir
- Re: [saag] Improving the CHAP protocol Peter Gutmann
- Re: [saag] Improving the CHAP protocol Alan DeKok
- Re: [saag] Improving the CHAP protocol John Mattsson
- Re: [saag] Improving the CHAP protocol Peter Gutmann
- Re: [saag] Improving the CHAP protocol Maurizio Lombardi
- Re: [saag] Improving the CHAP protocol Black, David
- Re: [saag] Improving the CHAP protocol Alan DeKok
- Re: [saag] Improving the CHAP protocol Peter Gutmann
- Re: [saag] Improving the CHAP protocol Black, David
- Re: [saag] Improving the CHAP protocol Salz, Rich
- Re: [saag] Improving the CHAP protocol Jim Schaad
- Re: [saag] Improving the CHAP protocol Black, David
- Re: [saag] Improving the CHAP protocol Mark D. Baushke
- Re: [saag] Improving the CHAP protocol John Mattsson
- Re: [saag] Improving the CHAP protocol Dang, Quynh (Fed)