Add a simple S/MIME SignedData message, taken from an upcoming draft
of
https://datatracker.ietf.org/doc/draft-autocrypt-lamps-protected-headers/
RFC 8551 describes a SignedData, a one-part clearsigned object that is
more resistant to common patterns of MTA message munging than
multipart/signed (but has the downside that it is only readable by
clients that implement S/MIME).
To make sure sure notmuch can handle this kind of object, we want to
know a few things:
Already working:
- Is the content of the SignedData object indexed? It actually is
right now because of dumb luck -- i think we're indexing the raw
CMS object and it happens to contain the cleartext of the message
in a way that we can consume it before passing it on to Xapian.
- Are we accidentally indexing the embedded PKCS#7 certificates? We
don't want to, and for some reason I don't understand, our indexing
is actually skipping the embedded certificates already. That's
good!
Still need fixing:
- do we know the MIME type of the embedded part?
- do we know that the message is signed?
- can notmuch-show read its content?
- can notmuch-show indicate the signature validity?
- can notmuch-reply properly quote and attribute content?
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
