Pascal Thank you for your prompt reply. I will clear my DISCUSS in a moment as you will change the text.
Agreed on all the points except for the 'nonce'. I know the concept of course but the sentence "was never used with this device" is still too strong IMHO. To comply, it would require to keep the history for ever... I would prefer a less stringent wording. -éric On 29/01/2020, 16:38, "Pascal Thubert (pthubert)" <[email protected]> wrote: Hello Eric : ) Many thanks for your review! I cc'ed SEC-DIR because we could really use their recommendation to solve some of your questions, more below. Please see below: > == DISCUSS == > > -- Section 4.4 -- > The length of the reserved field is not specified. Or am I missing something > obvious ? I concatenated the reserved fields in the picture and declared it as 40 bits. Also added the number of bits in the reserved fields of other structures. > ---------------------------------------------------------------------- > COMMENT: > ---------------------------------------------------------------------- > > == COMMENTS == > > -- Section 4.2 -- > While status is set to 0 when sending a NS, what is the expected behavior of a > receiver ? Changed to " In NS messages it MUST be set to 0 by the sender and ignored by the receiver. " > -- Section 4.3 and 4.4 -- > Why is the Pad Length field a 8-bit field while the actual padding will always be > less than 8 bytes. Suggest to make it a 3 or 4 bits field and extend the reserved > field. Actually I thought that if we want to extend the option in the future, it is better to indicate the length of the public key as follows: | Type | Length | Reserved| Public Key Length | Where: Public Key Length: 13-bit unsigned integer. The length of the Public Key field in bytes. Public Key: A variable-length field, size indicated in the Public Key Length field. JWK-Encoded Public Key [RFC7517] >Padding: A variable-length field completing the Public Key field to align to the next 8-bytes boundary. Works? > > -- Section 6.1 -- > About "Nonce option MUST contain a random Nonce value that was never used > with this device", how can it be done? Keeping a local history? Giving some > operational hints would bee welcome. Especially, when there are multiple 6LR in > the LLN: how can they synchronize the nonce? The nonce is used once, so there's no synchronization. A new pair is formed and exchanged at each validation. The nonce game used here appear to be common practice. Yes, there's usually a need of local history, and the fact that we get a nonce from both side, apart from guaranteeing that the result is effectively unique to both parties, also makes the chances for history to repeat very low. CC'ing SEC-DIR: Please help: if there is a reference for that practice, what it takes to maintain a nonce, and why we have a nonce from both sides? Trying to reinvent that text does not look like a good idea for this draft. > > -- References -- > Is there a reason why the crypto algorithms RFC 7748 and 8032 are not > normative? Interestingly they are informational. So that would be a downref. CC'ing SEC-DIR: Please help: should we make these refs normative? > > == NITS == > > -- Section 2.2 -- > To be honest, I am not a big fan of simply announcing concepts and referring to > many other RFCs. Suggest to mention which terms and concepts are defined in > each document. Else, the current section 2.2 mostly forces the readers to read > all the references. Yes and they are really there as additional reading, not normative. I changed the text to " The reader may get additional context for this specification from the following references" I also moved classical ND and SEND references to informational references. Works? > -- Section 6 -- > s/may use a same Crypto-ID/may use the same Crypto-ID/ ? Done Many thanks again Eric! Let's see what SEC-DIR thinks And a very happy new year (in France we have till Jan 31st to send wishes 😉) Pascal _______________________________________________ 6lo mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lo
