Commit graph

22 commits

Author SHA1 Message Date
Justus Winter
bf8aa34324 test: replace aging OpenPGP key used in the test suite
This replaces the old OpenPGPv4 key that is used in the test suite
with a more modern OpenPGPv4 key.  All cryptographic artifacts in the
test suite are updated accordingly.

Having old cryptographic artifacts in the test suite presents a
problem once the old algorithms are rejected by contemporary
implementations.

For reference, this is the old key.

  sec   rsa1024 2011-02-05 [SC]
        5AEAB11F5E33DCE875DDB75B6D92612D94E46381
  uid           [ unknown] Notmuch Test Suite <test_suite@notmuchmail.org> (INSECURE!)
  ssb   rsa1024 2011-02-05 [E]

And this is the new key.  Note that is has the same shape, but uses
Ed25519 and Cv25519 instead of 1024-bit RSA.

  sec   ed25519 2022-09-07 [SC]
        9A3AFE6C60065A148FD4B58A7E6ABE924645CC60
  uid           [ultimate] Notmuch Test Suite (INSECURE!) <test_suite@notmuchmail.org>
  ssb   cv25519 2022-09-07 [E]
2022-09-23 20:16:00 -03:00
Daniel Kahn Gillmor
8c29a5da09 cli/show: produce "email" element in sigstatus
When the certificate that signs a message is known to be valid, GMime
is capable of reporting on the e-mail address embedded in the
certificate.

We pass this information along to the caller of "notmuch show", as
often only the e-mail address of the certificate has actually been
checked/verified.

Furthermore, signature verification should probably at some point
compare the e-mail address of the caller against the sender address of
the message itself.  Having to parse what gmime thinks is a "userid"
to extract an e-mail address seems clunky and unnecessary if gmime
already thinks it knows what the e-mail address is.

See id:878s41ax6t.fsf@fifthhorseman.net for more motivation and discussion.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2021-06-26 13:07:47 -03:00
Daniel Kahn Gillmor
cb88b51fe5 smime: Pass PKCS#7 envelopedData to node_decrypt_and_verify
This change means we can support "notmuch show --decrypt=true" for
S/MIME encrypted messages, resolving several outstanding broken tests,
including all the remaining S/MIME protected header examples.

We do not yet handle indexing the cleartext of S/MIME encrypted
messages, though.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2020-05-22 22:11:51 -03:00
Daniel Kahn Gillmor
f12fb4d819 cli/show: If a leaf part has children, show them instead of omitting
Until we did PKCS#7 unwrapping, no leaf MIME part could have a child.

Now, we treat the unwrapped MIME part as the child of the PKCS#7
SignedData object.  So in that case, we want to show it instead of
deliberately omitting the content.

This fixes the test of the protected subject in
id:smime-onepart-signed@protected-headers.example.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2020-05-22 22:11:17 -03:00
Daniel Kahn Gillmor
b14d9ae204 smime: tests of X.509 certificate validity are known-broken on GMime < 3.2.7
When checking cryptographic signatures, Notmuch relies on GMime to
tell it whether the certificate that signs a message has a valid User
ID or not.

If the User ID is not valid, then notmuch does not report the signer's
User ID to the user.  This means that the consumer of notmuch's
cryptographic summary of a message (or of its protected headers) can
be confident in relaying the reported identity to the user.

However, some versions of GMime before 3.2.7 cannot report Certificate
validity for X.509 certificates.  This is resolved upstream in GMime
at https://github.com/jstedfast/gmime/pull/90.

We adapt to this by marking tests of reported User IDs for
S/MIME-signed messages as known-broken if GMime is older than 3.2.7
and has not been patched.

If GMime >= 3.2.7 and certificate validity still doesn't work for
X.509 certs, then there has likely been a regression in GMime and we
should fail early, during ./configure.

To break out these specific User ID checks from other checks, i had to
split some tests into two parts, and reuse $output across the two
subtests.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2020-05-22 22:04:57 -03:00
Daniel Kahn Gillmor
9055dfdae4 tests: disable CRL checks from gpgsm
GPGME has a strange failure mode when it is in offline mode, and/or
when certificates don't have any CRLs: in particular, it refuses to
accept the validity of any certificate other than a "root" cert.

This can be worked around by setting the `disable-crl-checks`
configuration variable for gpgsm.

I've reported this to the GPGME upstream at
https://dev.gnupg.org/T4883, but I have no idea how it will be
resolved.  In the meantime, we'll just work around it.

Note that this fixes the test for verification of
id:smime-multipart-signed@protected-headers.example, because
multipart/signed messages are already handled correctly (one-part
PKCS#7 messages will get fixed later).

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2020-04-30 18:02:38 -03:00
Daniel Kahn Gillmor
b415ec06c3 test/protected-headers: Add tests for S/MIME protected headers
Recognize the protected subject for S/MIME example protected header
messages.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2020-04-30 17:57:37 -03:00
Daniel Kahn Gillmor
9829533e92 index: avoid indexing legacy-display parts
When we notice a legacy-display part during indexing, it makes more
sense to avoid indexing it as part of the message body.

Given that the protected subject will already be indexed, there is no
need to index this part at all, so we skip over it.

If this happens during indexing, we set a property on the message:
index.repaired=skip-protected-headers-legacy-display

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2019-09-01 08:45:30 -03:00
Daniel Kahn Gillmor
c61e22d5cb cli/{show,reply}: skip over legacy-display parts
Make use of the previous changes to fast-forward past any
legacy-display parts during "notmuch show" and "notmuch reply".

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2019-09-01 08:44:17 -03:00
Daniel Kahn Gillmor
27b25e45dc test: avoid showing legacy-display parts
Enigmail generates a "legacy-display" part when it sends encrypted
mail with a protected Subject: header.  This part is intended to
display the Subject for mail user agents that are capable of
decryption, but do not know how to deal with embedded protected
headers.

This part is the first child of a two-part multipart/mixed
cryptographic payload within a cryptographic envelope that includes
encryption (that is, it is not just a cleartext signed message).  It
uses Content-Type: text/rfc822-headers.

That is:

A └┬╴multipart/encrypted
B  ├─╴application/pgp-encrypted
C  └┬╴application/octet-stream
*   ╤ <decryption>
D   └┬╴multipart/mixed; protected-headers=v1 (cryptographic payload)
E    ├─╴text/rfc822-headers; protected-headers=v1 (legacy-display part)
F    └─╴… (actual message body)

In discussions with jrollins, i've come to the conclusion that a
legacy-display part should be stripped entirely from "notmuch show"
and "notmuch reply" now that these tools can understand and interpret
protected headers.

You can tell when a message part is a protected header part this way:

 * is the payload (D) multipart/mixed with exactly two children?
 * is its first child (E) Content-Type: text/rfc822-headers?
 * does the first child (E) have the property protected-headers=v1?
 * do all the headers in the body of the first child (E) match
   the protected headers in the payload part (D) itself?

If this is the case, and we already know how to deal with the
protected header, then there is no reason to try to render the
legacy-display part itself for the user.

Furthermore, when indexing, if we are indexing properly, we should
avoid indexing the text in E as part of the message body.

'notmuch reply' is an interesting case: the standard use of 'notmuch
reply' will end up omitting all mention of protected Subject:.

The right fix is for the replying MUA to be able to protect its
headers, and for it to set them appropriately based on headers found
in the original message.

If a replying MUA is unable to protect headers, but still wants the
user to be able to see the original header, a replying MUA that
notices that the original message's subject differs from the proposed
reply subject may choose to include the original's subject in the
quoted/attributed text. (this would be a stopgap measure; it's not
even clear that there is user demand for it)

This test suite change indicates what we want to happen for this case
(the tests are currently broken), and includes three additional TODO
suggestions of subtle cases for anyone who wants to flesh out the test
suite even further.  (i believe all these cases should be already
fixed by the rest of this series, but haven't had time to write the
tests for the unusual cases)

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2019-09-01 08:32:56 -03:00
Daniel Kahn Gillmor
1c704dd22d cli/reply: pull proposed subject line from the message, not the index
Protected subject lines were being emitted in reply when the cleartext
of documents was indexed.  create_reply_message() was pulling the
subject line from the index, rather than pulling it from the
GMimeMessage object that it already has on hand.

This one-line fix to notmuch-reply.c solves that problem, and doesn't
cause any additional tests to fail.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2019-05-29 08:17:33 -03:00
Daniel Kahn Gillmor
06dedd0a83 test: reply (in cli and emacs) should protect indexed sensitive headers
These tests are currently broken!  When a protected subject is indexed
in the clear, it leaks in the reply headers :(

For emacs, we set up separate tests for when the protected header is
indexed in the clear and when it is unindexed.  neither case should
leak, but the former wasn't tested yet.

We will fix the two broken tests in a subsequent patch.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2019-05-29 08:17:20 -03:00
Daniel Kahn Gillmor
809a34a870 test: try indexing nested messages and protected headers
We want to make sure that internally-forwarded messages don't end up
"bubbling up" when they aren't actually the cryptographic payload.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2019-05-29 08:15:28 -03:00
Daniel Kahn Gillmor
bfed02bb0b test: after reindexing, only legitimate protected subjects are searchable
This test scans for all the possible protected headers (including
bogus/broken ones) that are present in the protected-headers corpus,
trying to make sure that only the ones that are not broken or
malformed show up in a search after re-indexing.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2019-05-29 08:15:18 -03:00
Daniel Kahn Gillmor
b36248a26e test: protected headers should work when both encrypted and signed.
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>
2019-05-29 08:14:57 -03:00
Daniel Kahn Gillmor
5c3a44681f indexing: record protected subject when indexing cleartext
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>
2019-05-29 08:14:44 -03:00
Daniel Kahn Gillmor
b7b553e732 cli/reply: ensure encrypted Subject: line does not leak in the clear
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>
2019-05-29 08:14:32 -03:00
Daniel Kahn Gillmor
996ef5710c test: show cryptographic envelope information for signed mails
Make sure that we emit the correct cryptographic envelope status for
cleartext signed messages.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2019-05-29 08:13:06 -03:00
Daniel Kahn Gillmor
1c879f3939 test: add test for missing external subject
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>
2019-05-29 08:12:49 -03:00
Daniel Kahn Gillmor
56416a5470 cli/show: add information about which headers were protected
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.
2019-05-29 08:11:50 -03:00
Daniel Kahn Gillmor
1c7fbbcc99 cli/show: emit payload subject instead of outside subject
Correctly fix the two outstanding tests so that the protected (hidden)
subject is properly reported.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
2019-05-29 08:05:01 -03:00
Daniel Kahn Gillmor
528f526f69 cli/show: add tests for viewing protected headers
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>
2019-05-29 08:04:32 -03:00