Re: [Pana] Fwd: New Version Notification for draft-yegin-pana-encr-avp-01.txt

Hi,

I've read the draft and I have four comments. Please see them below.

Best,
Yasuyuki Tanaka

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(1) Section 3
I found a typo in the last sentence.

 >   The length of PANA_ENCR_KEY depends on the integrity algorithm in
 >   use.

should be

     The length of PANA_ENCR_KEY depends on the *encryption* algorithm in
     use.

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(2) Section 4
I've not found text about key size of AES to be used for
AES_CTR. Probably 128-bit is assumed.

It would be better to clarify the key size to be used for the
algorithm and to use "AES128_CTR" or something instead of "AES_CTR".

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(3) Section 4
The definition of "q" is different between the draft and NIST
SP800-38C. In this draft, "q" is defined as "octet length of message
length field." But in NIST SP800-38C, "q" is defined as "The octet
length of the binary representation of the octet length of the
payload."

In addition, I don't realize what 'length of message length field'
means... Why is "q" 3? The length of "Message Length" field of PANA
Message Header is 2 octets...

Anyway, I think the following part might cause some confusion.

 >      AES-CTR (Counter) encryption algorithm as specified in
 >      [NIST_SP800_38A].  The formatting function and counter generation
 >      function as specified in Appendix A of [NIST_SP800_38C] are used,
 >      with the following parameters:
 >
 >
 >            n, octet length of nonce, is 12.
 >            q, octet length of message length field, is 3.

IMHO, it's better to say just "q is 3" as the definition of "q".

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(4) Section 4
It would be very helpful to provide an example of the first counter.

When Key-Id is 0x55667788, Session ID is 0xaabbccdd, and Sequence
Number is 0x11223344, the correct first counter is
0x0255667788aabbccdd11223344000001. is it correct?

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(2012/03/16 20:04), Robert Cragie wrote:
> I would like to move this forward so I am soliciting any comments from
> the PANA mailing list.
>
> Thanks
>
> Robert
>
> -------- Original Message --------
> Subject: 	New Version Notification for draft-yegin-pana-encr-avp-01.txt
> Date: 	Wed, 04 Jan 2012 01:53:07 -0800
> From: 	internet-drafts@ietf.org
> To: 	alper.yegin@yegin.org
> CC: 	robert.cragie@gridmerge.com, alper.yegin@yegin.org
>
>
>
> A new version of I-D, draft-yegin-pana-encr-avp-01.txt has been successfully submitted by Alper Yegin and posted to the IETF repository.
>
> Filename:	 draft-yegin-pana-encr-avp
> Revision:	 01
> Title:		 Encrypting PANA AVPs
> Creation date:	 2012-01-04
> WG ID:		 Individual Submission
> Number of pages: 8
>
> Abstract:
>     This document specifies a mechanism for delivering PANA (Protocol for
>     Carrying Authentication for Network Access) AVPs (Attribute-Value
>     Pairs) in encrypted form.
>
>
>
>
> The IETF Secretariat
>
>
>
>
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