Re: [TLS] Comments on TLS-ECJ-PAKE draft

On Mon, Jul 18, 2016 at 3:06 AM, Dan Harkins <dharkins@lounge.org> wrote:
>
>   Hi Robert,
>
>   This draft moves the NamedCurve/EllipticCurveList into the
> ClientHello, and since the client sends X1 and ZKP(X1) in the
> ClientHello it means that is going to be a list of 1. It basically
> moves the client's key exchange portion from ClientKeyExchange into
> ClientHello. So basically, if a client wants to do TLS-ECJ-PAKE
> then that's the only thing it can offer and the parameters of
> that exchange are all selected by the client, not the server.
>
>   This is a fundamental change to TLS. If it's going to be offered,
> it's the only thing that can be offered and therefore the only thing
> that can be used. Seems like for a deployment either it's never used
> or it's the only thing used and that makes it sort of a proprietary
> protocol, not TLS.

This stems from the multiple rounds used in JPAKE. SPAKE2 uses only 2
rounds, and would be easier to put into TLS. I'm still working on the
draft, but haven't gotten to it in a while.

Sincerely,
Watson
>
>   Dan.
>
> On Thu, June 16, 2016 2:51 am, Robert Cragie wrote:
>> I would like to ask the working group for comments on the TLS-ECJ-PAKE
>> draft:
>>
>> https://tools.ietf.org/html/draft-cragie-tls-ecjpake-00
>>
>> Some brief notes:
>>
>> * This intended status is informational.
>> * The draft is based on TLS/DTLS 1.2 as the Thread group required basis on
>> existing RFCs wherever possible. For that reason and due to the WGs focus
>> on TLS 1.3, I have understood from the chairs that it would not have
>> received a great deal of attention from the WG, hence the intended status
>> of informational.
>> * The draft reflects the current use of the TLS_ECJPAKE_WITH_AES_128_CCM_8
>> cipher suite in Thread (http://threadgroup.org/).
>> * There is an experimental implementation in mbed TLS (
>> https://github.com/ARMmbed/mbedtls)
>> * The Thread group would like to get IANA assignments for 4 cipher suite
>> values and one ExtensionType value as soon as possible.
>> * There are at least four independent implementations, which have been
>> used
>> in interop. testing over the last 18 months.
>> * The security considerations recommend restriction of the use of this
>> cipher suite to Thread and similar applications and recommends it should
>> not be used with web browsers and servers (mainly due to the long
>> discussions regarding the use of PAKEs on this and other mailing lists).
>>
>> Robert
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>> https://www.ietf.org/mailman/listinfo/tls
>>
>
>
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