Up to this point, we've tested protected headers on messages that have
either been encrypted or signed, but not both.
This adds a couple tests of signed+encrypted messages, one where the
subject line is masked (outside subject line is "Subject Unavailable")
and another where it is not (outside Subject: matches inner Subject:)
See the discussion at
https://dkg.fifthhorseman.net/blog/e-mail-cryptography.html#protected-headers
for more details about the nuances between signed, stripped, and
stubbed headers.
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
When indexing the cleartext of an encrypted message, record any
protected subject in the database, which should make it findable and
visible in search.
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Now that we can decrypt headers, we want to make sure that clients
using "notmuch reply" to prepare a reply don't leak cleartext in their
subject lines. In particular, the ["reply-headers"]["Subject"] should
by default show the external Subject.
A replying MUA that intends to protect the Subject line should show
the user the Subject from ["original"]["headers"]["Subject"] instead
of using ["reply-headers"]["Subject"].
This minor asymmetry with "notmuch show" is intentional. While both
tools always render the cleartext subject line when they know it (in
["headers"]["Subject"] for "notmuch show" and in
["original"]["headers"]["Subject"] for "notmuch reply"), "notmuch
reply" should never leak something that should stay under encrypted
cover in "reply-headers".
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Make sure that we emit the correct cryptographic envelope status for
cleartext signed messages.
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Adding another test to ensure that we handle protected headers
gracefully when no external subject is present.
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
The header-mask member of the per-message crypto object allows a
clever UI frontend to mark whether a header was protected (or not).
And if it was protected, it contains enough information to show useful
detail to an interested user. For example, an MUA could offer a "show
what this message's Subject looked like on the wire" feature in expert
mode.
As before, we only handle Subject for now, but we might be able to
handle other headers in the future.
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Amended by db: tweaked schemata notation.
Correctly fix the two outstanding tests so that the protected (hidden)
subject is properly reported.
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Here we add several variant e-mail messages, some of which have
correctly-structured protected headers, and some of which do not. The
goal of the tests is to ensure that the right protected subjects get
reported.
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
