[Suit] draft-housley-suit-cose-hash-sig

[Michael Richardson <[e-mail]>]

I have read the -01 draft today.
I have not read [HASHSIG] yet.
I thought I'd try reading this first, to see what questions I had.

I have implemented COSE Sign1 with ECDSA in Ruby, so I have a grasp of
what we are trying to plug hash-sig *into*.


Suggestions:
1) would the structure show in section 3 be easier if it was described by
   CDDL?  I'm rather unclear about this.

2) I din't understand section 4, where it says:
      o  If the 'key_ops' field is present, it MUST include 'sign' when
                 creating a hash-based signature.

      o  If the 'key_ops' field is present, it MUST include 'verify'
                 when verifying a hash-based signature.

Clearly this is not something that travels over the network.  Is this
somehow indicating how to understand if one is dealing a public (verify) key
or a private (sign) key?

3) the variations: LMS_SHA256_M32_H20, and LMOTS_SHA256_N32_W2, etc. are
   listed, but I don't know if they need to be carried in the signature
   structure somehow.

4) I thought that perhaps we'd need CBOR or COSE specific way to transport
   the signatures.  I guess I shall read HASHSIG to find out what the
   signatures look like.

I understand draft-mcgrew-hash-sigs-11 is being advanced by CFRG.
I believe that SUIT should adopt this document, and should do so in the
current state.

I would like to have some examples in CBOR/COSE worked out with private keys
available in the appendices.

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        | network architect  [
]     [e-mail]  http://www.sandelman.ca/        |   ruby on rails    [

--
Michael Richardson <[e-mail]>, Sandelman Software Works
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