Re: [HOKEY] Change proposal for ERP-AAK - 3: Multiple CAP case support

[Glen Zorn <[e-mail]>]

On 9/29/2011 4:45 PM, Qin Wu wrote:

> Hi,
> As we discussed on the list to the draft-ietf-hokey-erp-aak-04, it is
> not difficult to support multiple CAP(s) case.
> However we should make sure each pMSK is calculated for each CAP using
> different Sequence number, therefore I propose to do the
> following change to allow two ways to avoid the same pMSK derived for
> multiple CAP,
> one way is
> 
> The multiple sequence numbers can be derived from SEQ field in the
> message header by following +1 rule.
> 
> e.g., we have 3 CAP, the SEQ field is set to the value 100
> 
> so the pMSK for CAP A will be derived using seqence number 100.
> 
>     the pMSK for CAP B will be derived using sequence number 100+1
> 
>    the pMSK for CAP C will be derived using sequence number 100+2
> 
>  

OK, how does the AAA server know which CAP to send which key?

> 
> The second way is directly using Sequence number field carried in the TV
> of the message for each CAP,and mandate
> 
> each sequence number asscicated with each CAP must always follow that
> CAP. Also I think if multiple Sequenced number TLV are carried for each CAP,
> 
> the SEQ field in the ERP/AAK message header should be set to smallest 
> value contained in the  Sequenced number TLVs. This is more flexible way
> comparing
> 
> with the first way. But I think it will be better to allow both.

I'm not sure that I understand this, would you mind explaining a little
more?  Also, if both are allowed, which one would be mandatory to implement?

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