[keyassure] crypto hash alg deprecation is a myth
Martin Rex <mrex@sap.com> Thu, 03 March 2011 05:08 UTC
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From: Martin Rex <mrex@sap.com>
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Date: Thu, 03 Mar 2011 06:09:15 +0100
In-Reply-To: <AANLkTinsXqdKgmo4=1kruFhNi1gTydTwhg1cZxFM0qo7@mail.gmail.com> from "Phillip Hallam-Baker" at Mar 2, 11 06:09:11 pm
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Cc: keyassure@ietf.org
Subject: [keyassure] crypto hash alg deprecation is a myth
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Phillip Hallam-Baker wrote: > > Further, even though we stopped using MD5 in the mid 90s This seems wrong for most "we" and most environments that I can think of, certainly for the use of TLS on the internet. The very little thing that TLSv1.0 changed at the beginning of the new millenium is that it removed MD5 from the PRF that derives the TLS session master-secret and traffic keys. TLS did not affect in any way the use of MD5 for digitial signatures. On my scorecard, neither deprecation of the MD5 hash algorithms, nor migration away from MD5 hash algorithm has happend so far. Firefox happily verifies md5WithRsaEncryption signatures on TLS server certs. Only digital signature algorithms based on MD4 and MD2 seem to have been disabled since 3.0.something. MSIE 8 on Windows 7 (and prior) will happily talk to TLS servers using certs signed not only with md5WithRsaSignature, but also md2WithRsaSignature and even (**cough**) md4WithRsaSignature! Some may think "but Windows has a FIPS-compliant crypto algs switch". This (carefully hidden) switch disables SSLv3, but does NOT affect the acceptance of TLS server certificates signed with md5withRsaEncryption, md2WithRsaEncryption or md4WithRsaEncryption. (If it is possible to disable md5WithRsaEncryption signature verification in Firefox 3.5 -- then it is sufficiently well hidden that I don't see it.) To me, the claim that MD5 in digital signatures was deprecated in mid-90's is seriously defying the real world. It may have happened in small isolated environments, but it definitely did not happen yet where TLS is used on the internet today. I'm puzzled why so many commercial CAs are fiercly resisting the deprecation of obsolete digital signature algorithms such as md2WithRsaEncryption and md5WithRsaEncryption by continuing to distribute TrustAnchors as self-signed X.509 certs with such signatures on them. Look in the cert store of your favourite browser, or look into Microsofts TrustList distribution that my Windows box tries polling from here: http://www.download.windowsupdate.com/msdownload/update/v3/static/trustedr/en/authrootstl.cab -Martin
- [keyassure] Opening issue #21: "Need to specify w… Warren Kumari
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Jakob Schlyter
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Martin Rex
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Martin Rex
- Re: [keyassure] Opening issue #21: "Need to speci… Martin Rex
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Martin Rex
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Stephen Farrell
- Re: [keyassure] Opening issue #21: "Need to speci… Nicholas Weaver
- Re: [keyassure] Opening issue #21: "Need to speci… Chris Palmer
- Re: [keyassure] Opening issue #21: "Need to speci… Stephen Farrell
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Nicholas Weaver
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Stephen Farrell
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Scott Schmit
- Re: [keyassure] Opening issue #21: "Need to speci… Stephen Farrell
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Warren Kumari
- Re: [keyassure] Opening issue #21: "Need to speci… Sean Turner
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Martin Rex
- [keyassure] crypto hash alg deprecation is a myth Martin Rex
- Re: [keyassure] crypto hash alg deprecation is a … Rob Stradling
- Re: [keyassure] crypto hash alg deprecation is a … Phillip Hallam-Baker
- Re: [keyassure] crypto hash alg deprecation is a … Andrew Sullivan
- Re: [keyassure] Opening issue #21: "Need to speci… Warren Kumari
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] crypto hash alg deprecation is a … Peter Gutmann
- Re: [keyassure] Opening issue #21: "Need to speci… Peter Gutmann
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Nicholas Weaver
- Re: [keyassure] Opening issue #21: "Need to speci… Yoav Nir
- Re: [keyassure] Opening issue #21: "Need to speci… Peter Gutmann
- Re: [keyassure] Opening issue #21: "Need to speci… Andrew Sullivan
- Re: [keyassure] Opening issue #21: "Need to speci… Martin Rex
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Peter Gutmann
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Andrew Sullivan
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… bmanning
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Murray S. Kucherawy
- Re: [keyassure] Opening issue #21: "Need to speci… Murray S. Kucherawy
- Re: [keyassure] Opening issue #21: "Need to speci… Ben Laurie
- Re: [keyassure] Opening issue #21: "Need to speci… Jakob Schlyter
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… George Barwood
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Jakob Schlyter
- Re: [keyassure] Opening issue #21: "Need to speci… Martin Rex
- Re: [keyassure] Opening issue #21: "Need to speci… Yoav Nir
- Re: [keyassure] Opening issue #21: "Need to speci… Chris Palmer
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Warren Kumari
- Re: [keyassure] Opening issue #21: "Need to speci… Chris Palmer
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Chris Palmer
- Re: [keyassure] Opening issue #21: "Need to speci… Peter Gutmann
- Re: [keyassure] Opening issue #21: "Need to speci… bmanning
- Re: [keyassure] Opening issue #21: "Need to speci… Brian Smith
- Re: [keyassure] Opening issue #21: "Need to speci… Jakob Schlyter
- Re: [keyassure] Opening issue #21: "Need to speci… Ben Laurie
- Re: [keyassure] Opening issue #21: "Need to speci… Rob Stradling
- Re: [keyassure] Opening issue #21: "Need to speci… George Barwood
- Re: [keyassure] Opening issue #21: "Need to speci… Sean Turner
- Re: [keyassure] Opening issue #21: "Need to speci… Nicholas Weaver
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Martin Rex
- Re: [keyassure] Opening issue #21: "Need to speci… bmanning
- Re: [keyassure] Opening issue #21: "Need to speci… bmanning
- Re: [keyassure] Opening issue #21: "Need to speci… Yoav Nir
- Re: [keyassure] Opening issue #21: "Need to speci… Phillip Hallam-Baker
- Re: [keyassure] Opening issue #21: "Need to speci… Chris Palmer
- Re: [keyassure] Opening issue #21: "Need to speci… Peter Gutmann
- Re: [keyassure] Opening issue #21: "Need to speci… Peter Gutmann
- Re: [keyassure] Opening issue #21: "Need to speci… Peter Gutmann
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Warren Kumari
- Re: [keyassure] Opening issue #21: "Need to speci… Paul Hoffman
- Re: [keyassure] Opening issue #21: "Need to speci… Warren Kumari
- Re: [keyassure] Opening issue #21: "Need to speci… Tony Hansen