associating a property with a subpart of a message

[David Bremner]

Daniel Kahn Gillmor <dkg at fifthhorseman.net> writes:

> hey folks--
>
> I have some message properties i'd like to cache in notmuch that
> strictly apply to specific subparts of the message.  (e.g. session keys
> for an encrypted part, signature verification status of a signed part)
>
> let's assume that for any given copy of a message, we have a reliable
> "address" scheme for a part (e.g. "1.2.1.1").
>
> However, this becomes confusing with multiple copies of a given message.
> It's possible that one copy of the message has one MIME structure, but
> mangling (by MTAs, mailing lists, etc) result in a different MIME
> structure in another copy.
>
> For cryptographic properties, it might be nice to associate a subpart
> with a particular cryptographic digest of the subpart itself.
>
> Alternately, from a filesystem perspective, maybe it would be better to
> label the subpart based on the underlying physical file, and the
> subpart's "address".

A hybrid option would be to use a hash of the file + 1.2.1.1. address
scheme. My thinking here is a bit vague, but I can imagine such has hash
being useful either for content addressible mailstore, or for
disambiguating message-id collisions.

d