django.utils.translation.ugettext is a deprecated alias of
django.utils.translation.gettext as of Django 3.0, and will be removed
in Django 4.0.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
A bug in the implementation of the can_forge_sender permission
(previously is_api_super_user) resulted in users with this permission
being able to send messages appearing as if sent by a system bots,
including to other organizations hosted by the same Zulip installation.
- The send message API had a bug allowing an api super user to
use forging to send messages to other realms' streams, as a
cross-realm bot. We fix this most directly by eliminating the
realm_str parameter - it is not necessary for any valid current use
case. The email gateway doesn't use this API despite the comment in
that block suggesting otherwise.
- The conditionals inside access_stream_for_send_message are changed up
to improve security. They were generally not ordered very well,
allowing the function to successfully return due to very weak
acceptance conditions - skipping the higher importance checks that
should lead to raising an error.
- The query count in test_subs is decreased because
access_stream_for_send_message returns earlier when doing its check
for a cross-realm bot sender - some subscription checking queries are
skipped.
- A linkifier test in test_message_dict needs to be changed. It didn't
make much sense in the first place, because it was creating a message
by a normal user, to a stream outside of the user's realm. That
shouldn't even be allowed.