When SMTP servers receive 8-bit email messages, possibly with only LF as line ending, some of them decide to change said LF to CRLF. Some mailing list softwares, when receive 8-bit email messages, decide to encode those messages in base64 or quoted-printable. If an email is transfered through above mail servers, then distributed by such mailing list softwares, the recipients will receive an email contains a patch mungled with CRLF encoded inside another encoding. Thus, such CR couldn't be dropped by "mailsplit". Hence, the mailed patch couldn't be applied cleanly. Such accidents have been observed in the wild [1]. Instead of silently rejecting those messages, let's give our users some warnings if such CR is found. [1]: https://nmbug.notmuchmail.org/nmweb/show/m2lf9ejegj.fsf%40guru.guru-group.fi Signed-off-by: Đoàn Trần Công Danh <congdanhqx@xxxxxxxxx> --- mailinfo.c | 14 ++++++++++++++ mailinfo.h | 1 + t/t5100-mailinfo.sh | 15 +++++++++++++++ t/t5100/quoted-cr-info | 5 +++++ t/t5100/quoted-cr-msg | 2 ++ t/t5100/quoted-cr-patch | 22 ++++++++++++++++++++++ t/t5100/quoted-cr.mbox | 22 ++++++++++++++++++++++ 7 files changed, 81 insertions(+) create mode 100644 t/t5100/quoted-cr-info create mode 100644 t/t5100/quoted-cr-msg create mode 100644 t/t5100/quoted-cr-patch create mode 100644 t/t5100/quoted-cr.mbox diff --git a/mailinfo.c b/mailinfo.c index 5681d9130d..dcf579700d 100644 --- a/mailinfo.c +++ b/mailinfo.c @@ -994,6 +994,11 @@ static void handle_filter_flowed(struct mailinfo *mi, struct strbuf *line, const char *rest; if (!mi->format_flowed) { + if (len >= 2 && + line->buf[len - 2] == '\r' && + line->buf[len - 1] == '\n') { + mi->have_quoted_cr = 1; + } handle_filter(mi, line); return; } @@ -1033,6 +1038,12 @@ static void handle_filter_flowed(struct mailinfo *mi, struct strbuf *line, handle_filter(mi, line); } +static void summarize_quoted_cr(struct mailinfo *mi) +{ + if (mi->have_quoted_cr) + warning("quoted CR detected"); +} + static void handle_body(struct mailinfo *mi, struct strbuf *line) { struct strbuf prev = STRBUF_INIT; @@ -1051,6 +1062,8 @@ static void handle_body(struct mailinfo *mi, struct strbuf *line) handle_filter(mi, &prev); strbuf_reset(&prev); } + summarize_quoted_cr(mi); + mi->have_quoted_cr = 0; if (!handle_boundary(mi, line)) goto handle_body_out; } @@ -1100,6 +1113,7 @@ static void handle_body(struct mailinfo *mi, struct strbuf *line) if (prev.len) handle_filter(mi, &prev); + summarize_quoted_cr(mi); flush_inbody_header_accum(mi); diff --git a/mailinfo.h b/mailinfo.h index 79b1d6774e..b394ef9bce 100644 --- a/mailinfo.h +++ b/mailinfo.h @@ -24,6 +24,7 @@ struct mailinfo { struct strbuf charset; unsigned int format_flowed:1; unsigned int delsp:1; + unsigned int have_quoted_cr:1; char *message_id; enum { TE_DONTCARE, TE_QP, TE_BASE64 diff --git a/t/t5100-mailinfo.sh b/t/t5100-mailinfo.sh index 147e616533..c7ea1b30df 100755 --- a/t/t5100-mailinfo.sh +++ b/t/t5100-mailinfo.sh @@ -228,4 +228,19 @@ test_expect_success 'mailinfo handles unusual header whitespace' ' test_cmp expect actual ' +check_quoted_cr_mail () { + git mailinfo -u "$@" quoted-cr-msg quoted-cr-patch \ + <"$DATA/quoted-cr.mbox" >quoted-cr-info 2>quoted-cr-err && + test_cmp "expect-cr-msg" quoted-cr-msg && + test_cmp "expect-cr-patch" quoted-cr-patch && + test_cmp "$DATA/quoted-cr-info" quoted-cr-info +} + +test_expect_success 'mailinfo warn CR in base64 encoded email' ' + sed "s/%%/$(printf \\015)/" "$DATA/quoted-cr-msg" >expect-cr-msg && + sed "s/%%/$(printf \\015)/" "$DATA/quoted-cr-patch" >expect-cr-patch && + check_quoted_cr_mail && + grep "quoted CR detected" quoted-cr-err +' + test_done diff --git a/t/t5100/quoted-cr-info b/t/t5100/quoted-cr-info new file mode 100644 index 0000000000..dab2228b70 --- /dev/null +++ b/t/t5100/quoted-cr-info @@ -0,0 +1,5 @@ +Author: A U Thor +Email: mail@xxxxxxxxxxx +Subject: sample +Date: Mon, 3 Aug 2020 22:40:55 +0700 + diff --git a/t/t5100/quoted-cr-msg b/t/t5100/quoted-cr-msg new file mode 100644 index 0000000000..a148bc7e26 --- /dev/null +++ b/t/t5100/quoted-cr-msg @@ -0,0 +1,2 @@ +On different distro, pytest is suffixed with different patterns.%% +%% diff --git a/t/t5100/quoted-cr-patch b/t/t5100/quoted-cr-patch new file mode 100644 index 0000000000..580e2bddb8 --- /dev/null +++ b/t/t5100/quoted-cr-patch @@ -0,0 +1,22 @@ +---%% + configure | 2 +-%% + 1 file changed, 1 insertion(+), 1 deletion(-)%% +%% +diff --git a/configure b/configure%% +index db3538b3..f7c1c095 100755%% +--- a/configure%% ++++ b/configure%% +@@ -814,7 +814,7 @@ if [ $have_python3 -eq 1 ]; then%% + printf "Checking for python3 pytest (>= 3.0)... "%% + conf=$(mktemp)%% + printf "[pytest]\nminversion=3.0\n" > $conf%% +- if pytest-3 -c $conf --version >/dev/null 2>&1; then%% ++ if "$python" -m pytest -c $conf --version >/dev/null 2>&1; then%% + printf "Yes.\n"%% + have_python3_pytest=1%% + else%% +-- %% +2.28.0%% +_______________________________________________ +example mailing list -- list@xxxxxxxxxxx +To unsubscribe send an email to list-leave@xxxxxxxxxxx diff --git a/t/t5100/quoted-cr.mbox b/t/t5100/quoted-cr.mbox new file mode 100644 index 0000000000..6ea9806a6b --- /dev/null +++ b/t/t5100/quoted-cr.mbox @@ -0,0 +1,22 @@ +From: A U Thor <mail@xxxxxxxxxxx> +To: list@xxxxxxxxxxx +Subject: [PATCH v2] sample +Date: Mon, 3 Aug 2020 22:40:55 +0700 +Message-Id: <msg-id@xxxxxxxxxxx> +Content-Type: text/plain; charset="utf-8" +Content-Transfer-Encoding: base64 + +T24gZGlmZmVyZW50IGRpc3RybywgcHl0ZXN0IGlzIHN1ZmZpeGVkIHdpdGggZGlmZmVyZW50IHBh +dHRlcm5zLg0KDQotLS0NCiBjb25maWd1cmUgfCAyICstDQogMSBmaWxlIGNoYW5nZWQsIDEgaW5z +ZXJ0aW9uKCspLCAxIGRlbGV0aW9uKC0pDQoNCmRpZmYgLS1naXQgYS9jb25maWd1cmUgYi9jb25m +aWd1cmUNCmluZGV4IGRiMzUzOGIzLi5mN2MxYzA5NSAxMDA3NTUNCi0tLSBhL2NvbmZpZ3VyZQ0K +KysrIGIvY29uZmlndXJlDQpAQCAtODE0LDcgKzgxNCw3IEBAIGlmIFsgJGhhdmVfcHl0aG9uMyAt +ZXEgMSBdOyB0aGVuDQogICAgIHByaW50ZiAiQ2hlY2tpbmcgZm9yIHB5dGhvbjMgcHl0ZXN0ICg+ +PSAzLjApLi4uICINCiAgICAgY29uZj0kKG1rdGVtcCkNCiAgICAgcHJpbnRmICJbcHl0ZXN0XVxu +bWludmVyc2lvbj0zLjBcbiIgPiAkY29uZg0KLSAgICBpZiBweXRlc3QtMyAtYyAkY29uZiAtLXZl +cnNpb24gPi9kZXYvbnVsbCAyPiYxOyB0aGVuDQorICAgIGlmICIkcHl0aG9uIiAtbSBweXRlc3Qg +LWMgJGNvbmYgLS12ZXJzaW9uID4vZGV2L251bGwgMj4mMTsgdGhlbg0KICAgICAgICAgcHJpbnRm +ICJZZXMuXG4iDQogICAgICAgICBoYXZlX3B5dGhvbjNfcHl0ZXN0PTENCiAgICAgZWxzZQ0KLS0g +DQoyLjI4LjANCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f +CmV4YW1wbGUgbWFpbGluZyBsaXN0IC0tIGxpc3RAZXhhbXBsZS5vcmcKVG8gdW5zdWJzY3JpYmUg +c2VuZCBhbiBlbWFpbCB0byBsaXN0LWxlYXZlQGV4YW1wbGUub3JnCg== -- 2.31.1.448.g9c2f8508d1
