Closes#2420
We add rate limiting (max X emails withing Y seconds per realm) to the
email mirror. By creating RateLimitedRealmMirror class, inheriting from
RateLimitedObject, and rate_limit_mirror_by_realm function, following a
mechanism used by rate_limit_user, we're able to have this
implementation mostly rely on the already existing, and proven over
time, rate_limiter.py code. The rules are configurable in settings.py in
RATE_LIMITING_MIRROR_REALM_RULES, analogically to RATE_LIMITING_RULES.
Rate limit verification happens in the MirrorWorker in
queue_processors.py. We don't rate limit missed message emails, as due
to using one time addresses, they're not a spam threat.
test_mirror_worker is adapted to the altered MirrorWorker code and a new
test - test_mirror_worker_rate_limiting is added in test_queue_worker.py
to provide coverage for these changes.
To prepare for changing how the stream name gets encoded into mirror
email addresses while making sure old addresses keep working, we ignore
the stream_name part when receiving emails into the mirror and we only
look at the email_token to identify into which stream to mirror the
email.
Addresses point 2 of #10612. We use a regex to detect if a form
of FWD indicator is present at the beginning of the subject, which
means the message has been forwarded.
remove_quotations argument is added to a couple of functions where
it's necessary.
In filter_footer, the criteria for a line to be a possible beginning
of a footer is changed to line.strip() == "--", instead of
line.strip().startswith("--"), because the former would remove
quotations from plaintext emails. This change makes sense, because
RFC 3676 specifies ""-- " as the separator line between the body
and the signature of a message":
https://tools.ietf.org/html/rfc3676
We remove the 'subject' argument of process_stream_message and make
subject processing happen inside the function, as it's a more
appropriate place than the general process_message function and is
needed to have a good way of disabling removing quotations in forwarded
emails sent into the mirror.
Fixes part 3 of #10612. When sending an email to the email mirror to a
stream address, if "+show-sender" is added in the address, the stream
message will now include "From: <sender>" at the top.
For internal stream messages, most of the time, we have access to
a Stream object. For the few corner cases where we don't, it is a
much cleaner approach to have a separate function that accepts a
stream name than having one multi-option helper that accepts both
names and objects.
If the caller has access to a Stream object, it is wasteful to
query a database for a stream by ID or name. In addition, not
having to go through stream names eliminates various classes of
possible bugs involved with re-fetching the Stream object by name.
Previously, we had some hand-written logic for parsing the subject
line of the email's headers and turning it into a Python string using
each of the valid encodings for an email. That logic was buggy, and
sometimes resulted in a bytes object being passed into the
`send_zulip`, which would eventually throw an exception.
The fix for this is to use the Python standard library make_header
method for handling internationalized email headers.
https://stackoverflow.com/questions/7331351/python-email-header-decoding-utf-8
Fixes part 1 of #10612. We use a regex to remove RE:, FWD: (and similar
variations) from email subjects. Unit test is included, we add
subjects.json in fixtures containing various subjects to try the
stripping on.
When trying to find the email gateway address, use the
`email.util.getaddresses` function to deal with cases
where multiple recipients are included in the email header
or the stream address appears as an angle-addr with a
name given (e.g. if someone added it to their address book).
Added some other headers where the required address may
appear: "Resent" headers are sometimes used for forwarding,
and streams may also be found in CC. There is no way to find
the address if the email was recieved as a BCC.
This library was absolutely essential as part of our Python 2->3
migration process, but all of its calls should be either no-ops or
encode/decode operations.
Note also that the library has been wrong since the incorrect
refactoring in 1f9244e060.
Fixes#10807.
Change the truncation marker from `...` to `\n[message truncated]`
when receiving messages from the API or through e-mail. Also, update
tests to account for the new change.
Fix#10871.
Generally emails are not written with markdown in mind and hence
sometimes render in strange ways. This commit fixes a particular
issue that was causing whitespace before paragraphs to be treated
as code block due to which email content was being rendered in a
box that scrolls in right direction a lot.
Fixes: #7045.
They're rarely useful, usually displayed invisibly in most tools
anyway, and this helps make sure the message makes it into Zulip
rather than being rejected.
Redis and the Redis client know nothing but bytes. When we take a
`bytes` object it returns and pass it down as `subject` here, it
causes an exception deep inside message processing if the realm has
any filters, when `bugdown.subject_links` attempts to search the
subject for the filters, which are of course `str` patterns.
For symmetry, make the conversion to bytes on the storing side
explicit too.
This fixes a performance problem where we were previously starting up
a full Django process (~0.7s even on a fast machine) every time a new
email came in, potentially allowing users to accidentally DoS a Zulip
server. Now, we just post over HTTPS, allowing the existing thread
pool support to do its job.
- Add script wrapper to communicate postfix pipe with django web server
over HTTP(S). It uses shared_secret authentication mode.
- Add django view to process messages from email mirror server.
- Clean management command `email-mirror`. Left just functional
for cron email processing.
- Add routes for new tornado view.
- Change pipe script in master process postfix config template
based on updated script.
- Add tests.
Tweaked by tabbott to adjust the directory and set better defaults.
Fixes#2421.
A lot of care has been taken to ensure we're using the realm that the
message is being sent into, not the realm of the sender, to correctly
handle the logic for cross-realm bot users such as the notifications
bot.
If you supplied an unrecognizable address to our email system,
or you had EMAIL_GATEWAY_PATTERN configured wrong,
the get_missed_message_token_from_address() used to crash
hard and cryptically with a traceback saying that you can't
call startswith() on a None object.
Now we throw a ZulipEmailForwardError exception. This will
still lead to a traceback, but it should be easier to diagnose
the problem.
In our email mirror, we have a special format for missed
message emails that uses a 32-bit randomly generated token
that we put into redis that is then prefixed with "mm" for
a total of 34 characters.
We had a bug where we would mis-classify emails like
mmcfoo@example.com as being these system-generated emails
that were part of the redis setup.
It's actually a little unclear how the bug in the library
function would have manifested from the user's point of view,
but it was definitely buggy code, and it's possibly related in
a subtle way to an error report we got from a customer where
only one of their users, who happened to have a name like
mmcfoo, was having problems with the mirror.
This has the nice side effect of getting rid of the now-unnecessary
ADMIN_DOMAIN from this codepath -- we really just want whichever
realm ERROR_BOT is in.
This fixes a regression where missed message emails would not be sent
at all in the event that EMAIL_GATEWAY_PATTERN was unset.
The overall experience still isn't great, but it's better than crashing.
Fixes: #1411
[commit message expanded by tabbott]
This reverts commit f1f48f305e.
The use of sklearn unfortunately caused a substantial slowdown to the
Zulip provisioning process, which didn't seem worth it for a
relatively minor feature.
get_display_recipient's annotation clashes with other wrong annotations.
Fix those wrong annotations.
Since get_display_recipient returns a Union, use isinstance checks and
casts to make mypy checks succeed.
Prior to adding reply-to-missed-message-email functionality, adding
automated tests for simpler case - incoming stream messages. Added
to new file test_email_mirror.py.
Also removed the "if not body" code from process_stream_message that
will never run because of an upstream ZulipEmailForwardError exception.
The do_send_missedmessage_events_reply_in_zulip function in the email
mirror didn't support EMAIL_GATEWAY_PATTERN that wasn't of the form
%s@example.com (which resulted in replies to missed message emails failing
to be parsed).
* Fixes a few bugs with missed message address for PMs and huddles.
* Uses missed message address for all missed message reply-to headers on
the zulip.com realm.
(imported from commit 61dd09386e1bbdf9a5096e2400984d31e73a5b74)
The one time use address are a unique token which maps to stored stated
in redis. We store the user_id, recipient_id, and subject. When an email
is received at this address it is sent to the stored recipient by the
stored user. Anyone with this address can send a single message as this
user.
(imported from commit 4219417bdc30c033a6cf7a0c7c0939f7d0308144)
Previously, the email mirror queue worker used the API bindings to send
messages to Zulip, as if it were any other API client.
This is inefficient since we're running the worker inside the Django
context on a machine with database access; we can instead just use the
internal message-sending functions we use elsewhere. This also resolves
potential issues with SSL certificates, etc. that might occur when we
were previously making a HTTPS connection.
(imported from commit 6de8015829bec440f1af0199a2138828e86ed2a4)
Here, we don't want to check the uploading users' realm when determining
message privacy, because that'll prevent non-Zulip users from having
email-mirror-uploaded images. Instead, we just pass along the target
realm for the message explicitly to upload_message_image()
(imported from commit 6891261552135b1f41ff9da55ffe963ee5000556)