Re: [jose] Comments on draft-barnes-jose-spi-00

[Richard Barnes <[e-mail]>]

On Tue, Apr 2, 2013 at 2:52 PM, Hannes Tschofenig <[e-mail]
> wrote:

> On 04/02/2013 09:25 PM, Richard Barnes wrote:
>
>>
>> This is exactly my point.  These pre-negotiation cases prevent us from
>> having clear requirements levels.
>>
>> The goal of SPI is to explicitly say "SPI indicates that pre-negotiated
>> parameters are being used, so some things that are otherwise REQUIRED
>> might be missing."  That way, you can still have fields that MUST be
>> included in general, but if you include an SPI, you can omit them.
>>
>
> AHA. Now I got it.
>
> There are two options to address it:
>
> 1) Create a new parameter, as you suggested
>
> 2) Fix the specs
> (to allow parameters like alg to be optional)
>


Option 2 is not good, because it means that if you have an object that's
*not* pre-negotiated, you don't know what has to be there.  In fact, both
types of object (with and without pre-negotiation) benefit from Option 1,
since the stronger requirements could be applied in both cases.  In the
pre-negotiated case, you would just apply the requirements after
"rehydrating" the object.

--Richard