[Standards] IETF SASL WG meeting

[Peter Saint-Andre]

Alexey Melnikov wrote:
> Greg Hudson wrote:
> 
>> On Mon, 2007-12-10 at 10:20 -0800, Justin Karneges wrote:
>>  
>>
>>> I don't understand this talk about the SASL negotiation being
>>> attacked by a MITM when it is taking place over TLS.  There is brief
>>> mention of Bob possibly not having a certificate or Alice not
>>> trusting Bob's CA.  Does this mean the channel binding problem only
>>> affects anonymous/unauthenticated TLS?
>>>   
>> It strengthens your security properties in cases where you trust your
>> SASL authentication mechanism more than you trust the TLS authentication
>> mechanism.
>>  
>>
> I would rephrase this to say: if authentication of the client to the
> server happens in a different layer from authentication of the server to
> the client, then channel bindings are needed.
> 
>> If you trust TLS to authenticate the server to the client, then I
>> believe you can do client-to-server authentication without any form of
>> channel binding and you're fine.
>>  
>>
> Yes, mutual authentication at TLS layer + SASL EXTERNAL don't need any
> channel bindings.

This is an interesting discussion, but I'm wondering what changes we
need to make (if any) in rfc3920bis to handle this.

Peter

-- 
Peter Saint-Andre
https://stpeter.im/

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