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>

3 files changed, 84 insertions, 0 deletions

diff --git a/test/T356-protected-headers.sh b/test/T356-protected-headers.sh
index fee3b043..0a8d4bfa 100755
--- a/test/T356-protected-headers.sh
+++ b/test/T356-protected-headers.sh
@@ -99,4 +99,20 @@ output=$(notmuch search --format=json 'id:protected-header@crypto.notmuchmail.or
 test_json_nodes <<<"$output" \
                 'subject:[0]["subject"]="This is a protected header"'
 
+test_begin_subtest "verify protected header is both signed and encrypted"
+output=$(notmuch show --decrypt=true --format=json id:encrypted-signed@crypto.notmuchmail.org)
+test_json_nodes <<<"$output" \
+                'crypto:[0][0][0]["crypto"]={
+                   "signed":{"status": [{"status": "good", "fingerprint": "'$FINGERPRINT'", "userid": "'"$SELF_USERID"'", "created": 1525812676}],
+                   "encrypted": true, "headers": ["Subject"]},"decrypted": {"status": "full", "header-mask": {"Subject": "Subject Unavailable"}}}' \
+                'subject:[0][0][0]["headers"]["Subject"]="Rhinoceros dinner"'
+
+test_begin_subtest "verify protected header is signed even when not masked"
+output=$(notmuch show --decrypt=true --format=json id:encrypted-signed-not-masked@crypto.notmuchmail.org)
+test_json_nodes <<<"$output" \
+                'crypto:[0][0][0]["crypto"]={
+                   "signed":{"status": [{"status": "good", "fingerprint": "'$FINGERPRINT'", "userid": "'"$SELF_USERID"'", "created": 1525812676}],
+                   "encrypted": true, "headers": ["Subject"]},"decrypted": {"status": "full"}}' \
+                'subject:[0][0][0]["headers"]["Subject"]="Rhinoceros dinner"'
+
 test_done
diff --git a/test/corpora/protected-headers/encrypted-signed-not-masked.eml b/test/corpora/protected-headers/encrypted-signed-not-masked.eml
new file mode 100644
index 00000000..8dfd7c39
--- /dev/null
+++ b/test/corpora/protected-headers/encrypted-signed-not-masked.eml
@@ -0,0 +1,34 @@
+From: test_suite@notmuchmail.org
+To: test_suite@notmuchmail.org
+Subject: Rhinoceros dinner
+Date: Sat, 01 Jan 2000 12:00:00 +0000
+Message-ID: <encrypted-signed-not-masked@crypto.notmuchmail.org>
+MIME-Version: 1.0
+Content-Type: multipart/encrypted; boundary="=-=-=";
+	protocol="application/pgp-encrypted"
+
+--=-=-=
+Content-Type: application/pgp-encrypted
+
+Version: 1
+
+--=-=-=
+Content-Type: application/octet-stream
+
+-----BEGIN PGP MESSAGE-----
+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+=om0O
+-----END PGP MESSAGE-----
+--=-=-=--
diff --git a/test/corpora/protected-headers/encrypted-signed.eml b/test/corpora/protected-headers/encrypted-signed.eml
new file mode 100644
index 00000000..c97d8c3c
--- /dev/null
+++ b/test/corpora/protected-headers/encrypted-signed.eml
@@ -0,0 +1,34 @@
+From: test_suite@notmuchmail.org
+To: test_suite@notmuchmail.org
+Subject: Subject Unavailable
+Date: Sat, 01 Jan 2000 12:00:00 +0000
+Message-ID: <encrypted-signed@crypto.notmuchmail.org>
+MIME-Version: 1.0
+Content-Type: multipart/encrypted; boundary="=-=-=";
+	protocol="application/pgp-encrypted"
+
+--=-=-=
+Content-Type: application/pgp-encrypted
+
+Version: 1
+
+--=-=-=
+Content-Type: application/octet-stream
+
+-----BEGIN PGP MESSAGE-----
+
+hIwDxE023q1UqxYBBADAJ03D4w48sefkQsBWXUc1spTljROjVN+y5a2yCKtYMt3M
+wWMeQyem5hwLpLYRCfeIzXCrlBfpZffuOkA5okGGVEWFvJ5a1kZNZnH5Wg0ccBp7
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+6AGLN3KJETruI3Js6++aG+7tSkJ8Vo4WCVUR7oQROwF601X0QF/XghCoJCrx8B/1
+cw6Yb2wQj2nv3gw1rqWVsPVpAKsMc1yHx/2Vsee/VPtt4f67fSAMuJF3EJ6JkcK7
+tM761v69GoJGgvsie45pb1N2l/GfVMuwWU0wZhEsF7eXxqPzoE/kIGX1XIqleLaw
+On2kPSM5RgqV6gLOcw4WaFPi0oMbDhltNs72SV9cV6ZhhuwEQRq+u/K76NKLwte2
+R1JutAiuPZVF0WanmmiN6RbIpWOB5XxQfWagfr4vcf/03TaLP4hJMnqUdFMk20HP
+eI8TMQxkfryZK2Z6VxEBVdXhK05VEdkolmc4j9U+76A96Gd5zbYPApirkebmZatS
+X3rKKAiBqwWrFXi/7LNDoCwhRRmqDuHXruh3vZEcz+xiPfJh0G31GJQgIpE15Sv6
+trf20u3CXAFjHg9zPpSFV7uAOsqv7bg+xtG9PgN4aLCiVbXHsT0z6PAz+6K+SiKw
+QW8ZOtLikj5HyLAz/TDcsIShFaM3QHk2qq9RY10kmxlQVrf9Oyh3Wmc=
+=om0O
+-----END PGP MESSAGE-----
+--=-=-=--