Re: [TLS] Straw poll on TLS SRP status

Yoav Nir <ynir@checkpoint.com> Fri, 01 June 2007 08:25 UTC

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From: Yoav Nir <ynir@checkpoint.com>
Subject: Re: [TLS] Straw poll on TLS SRP status
Date: Fri, 01 Jun 2007 11:24:30 +0300
To: Peter Gutmann <pgut001@cs.auckland.ac.nz>
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I know SRP has the capability to do the whole key exchange, but why  
do we need it.

The problem that both extensions are trying to solve is the problem  
of using passwords for authentication within TLS. TLS has a perfectly  
good way for keying already.

But again, I'm not saying that SRP should not be used. I'm only  
saying that we don't need its key-exchange capabilities in this  
particular context.

On May 30, 2007, at 6:15 PM, Peter Gutmann wrote:

> Yoav Nir <ynir@checkpoint.com> writes:
>
>> I think SRP should not be a stand-alone extension, but rather that  
>> it should
>> be introduced as part of EAP.
>>
>> The choice is between separate extensions for SRP and for each  
>> authentication
>> method, or to introduce them all at once under EAP, as was done in  
>> IKEv2.
>
> Is it possible to do this though?  Using the taxonomy I posted  
> earlier, TLS-
> SRP would seem to fall into the "modify the crypto portion of the TLS
> handshake" bucket (alongside TLS-KRB5 and TLS-PSK), which means  
> that you
> couldn't really do it inside EAP.  Admittedly you could do a  
> standard TLS
> handshake and then follow it up with SRP inside EAP purely for the
> authentication portion, but that seems (a) messy (see draft-iab- 
> auth-mech-*)
> and (b) a bit of a waste of SRP's capabilities, since it can do the  
> whole key
> exchange step as well.
>
> Peter.
>


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