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Re: [TLS] simplistic renego protection

David-Sarah Hopwood <david-sarah@jacaranda.org> Thu, 19 November 2009 04:54 UTC

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Date: Thu, 19 Nov 2009 04:53:47 +0000
From: David-Sarah Hopwood <david-sarah@jacaranda.org>
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Subject: Re: [TLS] simplistic renego protection
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Martin Rex wrote:
> Robert Dugal wrote:
>> Our products do support step-up/SGC and some customers may still be
>> using it, or at least have servers with SGC certificates.
>> Since there is no vulnerability is this special case, should
>> some note be added to the draft? 
> 
> You mean like enumerating conceivable usage scenarios that
> TLS extension RI is very likely to break?
> 
> Maybe a spec where that section is very small or empty
> would be more appreciated by the community.

The reason why the fix breaks Step-Up has nothing to do with the use of
extensions, and the other proposals that have been made so far would
break Step-Up as well. It might be possible to avoid that, but only by
adding significant complexity and introducing greater risk of making
a mistake that might be exploitable. I'm opposed to adding that
complexity and risk.

-- 
David-Sarah Hopwood  ⚥  http://davidsarah.livejournal.com

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