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Re: [Cbor] [COSE] CBOR magic number, file format and tags

Michael Richardson <mcr+ietf@sandelman.ca> Thu, 21 January 2021 12:24 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: worley@ariadne.com
cc: Doug Ewell <doug@ewellic.org>, cose@ietf.org, cbor@ietf.org
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Subject: Re: [Cbor] [COSE] CBOR magic number, file format and tags
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Dale R. Worley <worley@ariadne.com> wrote:
    > "Doug Ewell" <doug@ewellic.org> writes:
    >>> Since very early in computing, operating systems have sought ways to
    >>> mark which files could be proposed by which programs.
    >>
    >> The word "proposed" feels very awkward here. Maybe "opened" or
    >> "manipulated," or some recasting of the sentence that talks about
    >> files "belonging to" programs, or something similar.

    > When I first read that, I mis-read it as "processed by".  I suspect
    > that is what is intended.

    > But ... Am I missing something?  Isn't a magic number provided by RFC
    > 8949 section 3.4.6?

    >    3.4.6.  Self-Described CBOR

    >    [...]  Tag number 55799 is defined for this purpose, specifically

That tells us that it might be CBOR.

It does not distinguish a CBOR encoded certificate from a CBOR encoded
RFC8366 artifact, for instance.

--
Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide

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