Re: [saag] AD review of draft-iab-crypto-alg-agility-06

Peter Gutmann <pgut001@cs.auckland.ac.nz> Tue, 25 August 2015 14:57 UTC

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From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: "saag@ietf.org" <saag@ietf.org>
Thread-Topic: [saag] AD review of draft-iab-crypto-alg-agility-06
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Date: Tue, 25 Aug 2015 14:56:52 +0000
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Subject: Re: [saag] AD review of draft-iab-crypto-alg-agility-06
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Viktor Dukhovni <ietf-dane@dukhovni.org>; writes:

>Inbound, Exchange does not and cannot know whether the client is
>authenticating the server certificate or ignoring it.

Argh, yeah, sorry, messed that one up, the issue was more with Outlook (i.e.
client-side) than Exchange (server-side), specifically the amount of pain
involved in configuring things to trust non-commercial-CA-issued certs.
Here's the 25-step process (which each step comprising several sub-steps, it's
pages and pages and pages of instructions) for Exchange 2010:

http://social.technet.microsoft.com/wiki/contents/articles/13916.how-to-use-a-self-signed-certificate-in-exchange-2010.aspx

Compare this to a cut&paste of:

openssl req -x509 -newkey rsa:2048 -nodes -keyout /etc/ssl/private/key.pem -out /etc/ssl/certs/cert.pem -days 3650 -subj '/CN=mail.example.com' 

(E&OE :-) for non-Exchange mail servers.

(I've long been an advocate of software auto-generating a key on install and
allowing the user to override it if they want further customisation, which
would probably make about, oh, 99% of things like this:

https://code.google.com/p/littleblackbox/

go away).

Peter.