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Re: [saag] [Cfrg] Further MD5 breaks: Creating a rogue CAcertificate

Dr Stephen Henson <lists@drh-consultancy.demon.co.uk> Mon, 05 January 2009 06:54 UTC

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Date: Wed, 31 Dec 2008 18:11:35 +0000
From: Dr Stephen Henson <lists@drh-consultancy.demon.co.uk>
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Cc: ietf-smime@imc.org, cfrg@irtf.org, saag@ietf.org
Subject: Re: [saag] [Cfrg] Further MD5 breaks: Creating a rogue CAcertificate
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Mike wrote:
> 
> I sent my last message a bit too hastily.  Other ideas that I was
> contemplating should have been mentioned including:
> 
>   - remove any unrecognized extensions
>   - remove tumors
> 
> Those could potentially cause problems if for some reason they were
> actually needed.  This one, though, shouldn't cause trouble:
> 
>   - add a private EKU with a random number (or two) in the OID
> 
> That would not mess up the serial number scheme in use or modify the
> subject name as has been suggested.
> 

Or add a non-critical extension with some randomness in it...

Steve.
-- 
Dr Stephen N. Henson.
Core developer of the   OpenSSL project: http://www.openssl.org/
Freelance consultant see: http://www.drh-consultancy.co.uk/
Email: shenson@drh-consultancy.co.uk, PGP key: via homepage.
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