util/crypto: add information about the payload part
authorDaniel Kahn Gillmor <dkg@fifthhorseman.net>
Sun, 26 May 2019 22:15:55 +0000 (18:15 -0400)
committerDavid Bremner <david@tethera.net>
Wed, 29 May 2019 11:02:45 +0000 (08:02 -0300)
commita6b0772b60d9191fcc291358eec3d78bfea31f1c
treeecaecc73958232fb50fd30dae97dc59afbe2a5ca
parent80728a95e6fd8bd1c4a4f8dd8040984ab5c4b04a
util/crypto: add information about the payload part

When walking the MIME tree, if we discover that we are at the
cryptographic payload, then we would like to record at least the
Subject header of the current MIME part.

In the future, we might want to record many other headers as well, but
for now we will stick with just the Subject.

See
https://dkg.fifthhorseman.net/blog/e-mail-cryptography.html#cryptographic-envelope
for more description of the Cryptographic Payload vs. the
Cryptographic Envelope.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
util/crypto.c
util/crypto.h