Re: [kitten] SPAKE and non-deterministic RFC 3961 checksums

"Henry B (Hank) Hotz, CISSP" <hbhotz@oxy.edu> Tue, 26 September 2017 05:04 UTC

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From: "Henry B (Hank) Hotz, CISSP" <hbhotz@oxy.edu>
In-Reply-To: <20170926022550.GZ96685@kduck.kaduk.org>
Date: Mon, 25 Sep 2017 22:04:15 -0700
Cc: Simo Sorce <simo@redhat.com>, kitten@ietf.org
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References: <x7d1sn5zyl8.fsf@equal-rites.mit.edu> <20170919015937.GN96685@kduck.kaduk.org> <1505920169.1143.15.camel@redhat.com> <20170923190527.GU96685@kduck.kaduk.org> <1506358991.3211.1.camel@redhat.com> <20170926022550.GZ96685@kduck.kaduk.org>
To: Benjamin Kaduk <kaduk@MIT.EDU>
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Subject: Re: [kitten] SPAKE and non-deterministic RFC 3961 checksums
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> On Sep 25, 2017, at 7:25 PM, Benjamin Kaduk <kaduk@MIT.EDU>; wrote:
> 
> That said, Greg noted on IRC that if we do have a "no DES and SPAKE
> together" requirement, the KDC knows the initial reply key and can
> do the right thing fairly easiliy, including rejecting optimistic
> attempts from (broken) clients.  So, I'm starting to come around to
> the camp of "prevent SPAKE with 1DES, and require all future mandatory
> checksum types to be deterministic".  (Possibly all future checksum
> types entirely, but that may be too aggressive.)

Do we really have that many single-des deployments to worry about anymore? Everything I know of, including AFS and AD/Windows, has better alternatives available and just waiting to be turned on. Surely nobody is still using JGSS in Java 1.4.

Personal email.  hbhotz@oxy.edu