Please look at this and see if you think it covers the required changes. https://github.com/cose-wg/cose-spec/pull/150
jim > -----Original Message----- > From: COSE [mailto:[email protected]] On Behalf Of Göran Selander > Sent: Thursday, May 19, 2016 6:52 AM > To: Jim Schaad <[email protected]> > Cc: [email protected]; [email protected] > Subject: Re: [COSE] FW: I-D Action: draft-ietf-cose-msg-12.txt > > Hi Jim > > A couple of questions related to applying COSE rather than issues with the > draft > itself. > > 1. As you know we are looking at building security protocols using COSE. > For EDHOC we need to support X.509 certificate based authentication of the DH > exchange. With PSK and RPK, which is currently described, EDHOC is an > exchange of COSE messages. What would be a natural way to include a public > key certificate in a COSE_Sign1 object, the public key of the certificate > intended > to be used by the recipient to verify the signature of the COSE object? > > > 2. Another thing we discussed previously was the detailed specification for > deriving the shared secret with ECDH, analogously to section 7.3.3 of > https://tools.ietf.org/html/draft-ietf-tls-tls13-12 > > I note in section 12.4.1 > > " The mathematics for Elliptic Curve Diffie-Hellman can be found in > [RFC6090]. In this document the algorithm is extended to be used > with the two curves defined in [RFC7748]. > > ECDH is parameterized by the following: > > o Curve Type/Curve: The curve selected controls not only the size of > the shared secret, but the mathematics for computing the shared > secret. “ > > > There are at least two kinds of shared secret, one is a point on a curve, > denoted > g^(j*k) in RFC6090, or alternatively a coordinate. Another is the byte string > derived from g^(j*k) or its coordinate, used for subsequent key derivation. > The > former is defined with the curve, but not necessarily the latter. > > For example in the case of RFC7748, section 6.1, "Alice and Bob can then use a > key-derivation > function that includes K, K_A, and K_B to derive a symmetric key.” > > > Section 11 in draft-ietf-cose-msg nicely describes the key derivation given > the > shared secret, but I can’t find the reference to the exact procedure for > obtaining > the shared secret starting from this draft. > > Not insisting on it be included in this draft. For now I just want a > confirmation > that I haven’t missed something. > > > Göran > > > > > On 2016-05-13 02:41, "COSE on behalf of Jim Schaad" <[email protected] > on behalf of [email protected]> wrote: > > >I believe that this draft represents all of the decisions that were > >taken at BA. I have been through the draft a couple of times to look > >for problems and I believe that it is now ready for a working group > >last call. > > > >Jim > > > > > >> -----Original Message----- > >> From: COSE [mailto:[email protected]] On Behalf Of internet- > >> [email protected] > >> Sent: Thursday, May 12, 2016 5:20 PM > >> To: [email protected] > >> Cc: [email protected] > >> Subject: [COSE] I-D Action: draft-ietf-cose-msg-12.txt > >> > >> > >> A New Internet-Draft is available from the on-line Internet-Drafts > >directories. > >> This draft is a work item of the CBOR Object Signing and Encryption > >>of the > >IETF. > >> > >> Title : CBOR Encoded Message Syntax > >> Author : Jim Schaad > >> Filename : draft-ietf-cose-msg-12.txt > >> Pages : 112 > >> Date : 2016-05-12 > >> > >> Abstract: > >> Concise Binary Object Representation (CBOR) is data format designed > >> for small code size and small message size. There is a need for the > >> ability to have the basic security services defined for this data > >> format. This document specifies processing for signatures, message > >> authentication codes, and encryption using CBOR. This document also > >> specifies a representation for cryptographic keys using CBOR. > >> > >> > >> The IETF datatracker status page for this draft is: > >> https://datatracker.ietf.org/doc/draft-ietf-cose-msg/ > >> > >> There's also a htmlized version available at: > >> https://tools.ietf.org/html/draft-ietf-cose-msg-12 > >> > >> A diff from the previous version is available at: > >> https://www.ietf.org/rfcdiff?url2=draft-ietf-cose-msg-12 > >> > >> > >> Please note that it may take a couple of minutes from the time of > >submission > >> until the htmlized version and diff are available at tools.ietf.org. > >> > >> Internet-Drafts are also available by anonymous FTP at: > >> ftp://ftp.ietf.org/internet-drafts/ > >> > >> _______________________________________________ > >> COSE mailing list > >> [email protected] > >> https://www.ietf.org/mailman/listinfo/cose > > > >_______________________________________________ > >COSE mailing list > >[email protected] > >https://www.ietf.org/mailman/listinfo/cose > > _______________________________________________ > COSE mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/cose _______________________________________________ COSE mailing list [email protected] https://www.ietf.org/mailman/listinfo/cose
