From cb522fb06ef534a485408de608984d1be6dbadfa Mon Sep 17 00:00:00 2001 From: Daniel Kahn Gillmor Date: Mon, 27 May 2019 22:46:53 -0400 Subject: [PATCH] test: add test for "Mixed-Up Mime" message mangling Some MTAs mangle e-mail messages in transit in ways that are repairable. Microsoft Exchange (in particular, the version running today on Office365's mailservers) appears to mangle multipart/encrypted messages in a way that makes them undecryptable by the recipient. I've documented this in section 4.1 "Mixed-up encryption" of draft -00 of https://tools.ietf.org/html/draft-dkg-openpgp-pgpmime-message-mangling Fortunately, it's possible to repair such a message, and notmuch can do that so that a user who receives an encrypted message from a user of office365.com can still decrypt the message. Enigmail already knows about this particular kind of mangling. It describes it as "broken PGP email format probably caused by an old Exchange server", and it tries to repair by directly changing the message held by the user. if this kind of repair goes wrong, the repair process can cause data loss (https://sourceforge.net/p/enigmail/bugs/987/, yikes). The tests introduced here are currently broken. In subsequent patches, i'll introduce a non-destructive form of repair for notmuch so that notmuch users can read mail that has been mangled in this way, and the tests will succeed. Signed-off-by: Daniel Kahn Gillmor --- test/T351-pgpmime-mangling.sh | 36 ++++++++++++++++++++++++++++++ test/corpora/mangling/mixed-up.eml | 33 +++++++++++++++++++++++++++ 2 files changed, 69 insertions(+) create mode 100755 test/T351-pgpmime-mangling.sh create mode 100644 test/corpora/mangling/mixed-up.eml diff --git a/test/T351-pgpmime-mangling.sh b/test/T351-pgpmime-mangling.sh new file mode 100755 index 00000000..f65b8a24 --- /dev/null +++ b/test/T351-pgpmime-mangling.sh @@ -0,0 +1,36 @@ +#!/usr/bin/env bash + +test_description='PGP/MIME message mangling' +. $(dirname "$0")/test-lib.sh || exit 1 + +add_gnupg_home +add_email_corpus mangling + +bodytext='["body"][0]["content"][1]["content"]="The password is \"abcd1234!\", please do not tell anyone.\n"' + +test_begin_subtest "show 'Mixed-Up' mangled PGP/MIME message correctly" +test_subtest_known_broken +output=$(notmuch show --format=json --decrypt=true id:mixed-up@mangling.notmuchmail.org) +test_json_nodes <<<"$output" \ + 'body:[0][0][0]'"$bodytext" + +test_begin_subtest "reply to 'Mixed-Up' mangled PGP/MIME message correctly" +test_subtest_known_broken +output=$(notmuch reply --format=json --decrypt=true id:mixed-up@mangling.notmuchmail.org) +test_json_nodes <<<"$output" \ + 'body:["original"]'"$bodytext" + +test_begin_subtest "repaired 'Mixed-up' messages can be found with index.repaired=mixedup" +test_subtest_known_broken +output=$(notmuch search --output=messages property:index.repaired=mixedup) +test_expect_equal "$output" id:mixed-up@mangling.notmuchmail.org + +test_begin_subtest "index cleartext of 'Mixed-Up' mangled PGP/MIME message" +test_expect_success 'notmuch reindex --decrypt=true id:mixed-up@mangling.notmuchmail.org' + +test_begin_subtest "search cleartext of 'Mixed-Up' mangled PGP/MIME message" +test_subtest_known_broken +output=$(notmuch search --output=messages body:password) +test_expect_equal "$output" id:mixed-up@mangling.notmuchmail.org + +test_done diff --git a/test/corpora/mangling/mixed-up.eml b/test/corpora/mangling/mixed-up.eml new file mode 100644 index 00000000..a09f6191 --- /dev/null +++ b/test/corpora/mangling/mixed-up.eml @@ -0,0 +1,33 @@ +From: test_suite@notmuchmail.org +To: test_suite@notmuchmail.org +Subject: Here is the password +Date: Sat, 01 Jan 2000 12:00:00 +0000 +Message-ID: +MIME-Version: 1.0 +Content-Type: multipart/mixed; boundary="=-=-=" + +--=-=-= +Content-Type: text/plain; charset="us-ascii" +Content-Transfer-Encoding: quoted-printable + + +--=-=-= +Content-Type: application/pgp-encrypted +Content-Transfer-Encoding: base64 + +VmVyc2lvbjogMQ0K + +--=-=-= +Content-Type: application/octet-stream +Content-Transfer-Encoding: base64 + +LS0tLS1CRUdJTiBQR1AgTUVTU0FHRS0tLS0tDQoNCmhJd0R4RTAyM3ExVXF4WUJCQUNwNzBlN0tQ +eTlPWWFoZUlya0x6bWhxMWxScW15NTFhTDFqQkwwSy9xTjdyZksNCkJaRUcxY1I4amVMalRGZFBL +UExWS0pJODByN0ZnS0kweXd2V3ZsNlIxYUUxVHk1Qm5WWFQ5WHpDckVIN2ZxQ2wNClNLSzgyRXZv +bFhUb2hBWkhVcmg2SzY2ZVFRVFRJQUMxbjdCMEE4aEVyemtnYU00K3NlTjNMbHZlelQ2VExOS00N +CkFUcHFzRWJNMk1WckdndzBiM29Vc0dHQVBFdDJNbWpORVlzcmlLbnF3dDZkSkRaYy8vWHloamdN +UWF5aUQ4ZGENCk4xZ1Qzb3FndS9nS0NwQlpEWXpIZjlPdFZpMlVubEZEV3k2cnJNWkxqV0RuSXY0 +dmU5UG4vcW9sd0hWanpkSjENClpmak5DNXQwejNYQURLR3JqTjl3dXRyNHFtN1NUVzFySEFYSFA2 +OFRRVHhJMHFnSktqUFhOS1dFdzZnPQ0KPXBKRzQNCi0tLS0tRU5EIFBHUCBNRVNTQUdFLS0tLS0N +Cg== +--=-=-=--