The content of a message is truncated to `MAX_MESSAGE_LENGTH`, which
is 1000 characters. Since the email gateway places attachments at the
very end of the extracted body, that means that they are the first
thing to get truncated off.
That is, if an incoming email message contains 1000 `a`s and an image
attachment, the link that attaches the attachment to the message will
get truncated off, leaving it dangling in the database.
Truncate the message body content separately from the attachment links
which are included at the end of the body.
When the email mirror gateway is sending messages "as" a user (as
triggered by having access to the missed-message email address),
attachments were still created as the Email Gateway bot. Since the
sender (the end-user) was not the owner of those attachments (the
gateway bot), nor were they referenced yet anywhere, this resulted in
the attachments being "orphaned" and not allowed to be accessed by
anyone -- despite the attachment links being embedded in the message.
This was accompanied by the error:
```
WARN [] User 12345 tried to share upload 123/3LkSA4OcoG6OpAknS2I0SFAQ/example.jpf in message 123456, but lacks permission
INFO [zerver.lib.email_mirror] Successfully processed email from user 12345 to example-stream
```
We solve this by creating attachment objects as the users the message
will be sent from.
These limits don't appear to provide useful security benefits, and
they do impact usability because they prevented email-based users from
replying more than once, or from replying to message more than 5 days
old.
Fixes#2755.
Fixes#19994.
These characters are not allowed and trying to create a Zulip message
with those characters throws a JsonableError in check_stream_topic.
We don't want to reject emails with those chars in the subject, so
it's best to just modify it appropriately.
Now that we can assume Python 3.6+, we can use the
email.headerregistry module to replace hacky manual email address
parsing.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
These logs were pretty spammy, and there have long been much better
ways to communicate to system administrators that the incoming email
gateway is great, including, most importantly, in the section of the
emails themselves that explains how replying works.
On replying to an email notifcation from a stream where the user
does not come under the stream_post_policy will subsequently result
in a failure. In such a case, the user does not receive feedback
regarding the failure.
Notify the user via notification bot if their email
message failed to send.
Fixes#16642.
We always want to do these at the same time. Previously, message
editing did too much stripping (fixes#16837) and failed to check for
NUL bytes.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
There are three functional side effects:
• Correct an insignificant but mathematically offensive bias toward
repeated characters in generate_api_key introduced in commit
47b4283c4b4c70ecde4d3c8de871c90ee2506d87; its entropy is increased
from 190.52864 bits to 190.53428 bits.
• Use the base32 alphabet in confirmation.models.generate_key; its
entropy is reduced from 124.07820 bits to the documented 120 bits, but
now it uses 1 syscall instead of 24.
• Use the base32 alphabet in get_bigbluebutton_url; its entropy is
reduced from 51.69925 bits to 50 bits, but now it uses 1 syscall
instead of 10.
(The base32 alphabet is A-Z 2-7. We could probably replace all of
these with plain secrets.token_urlsafe, since I expect most callers
can handle the full urlsafe_b64 alphabet A-Z a-z 0-9 - _ without
problems.)
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This commit rewrites the way addresses are collected. If
the header with the address is not an AddressHeader (for instance,
Delivered-To and Envelope-To), we take its string representation.
Fixes: #15864 ("Error in email_mirror - _UnstructuredHeader has no attribute addresses").
Fixes#2665.
Regenerated by tabbott with `lint --fix` after a rebase and change in
parameters.
Note from tabbott: In a few cases, this converts technical debt in the
form of unsorted imports into different technical debt in the form of
our largest files having very long, ugly import sequences at the
start. I expect this change will increase pressure for us to split
those files, which isn't a bad thing.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Automatically generated by the following script, based on the output
of lint with flake8-comma:
import re
import sys
last_filename = None
last_row = None
lines = []
for msg in sys.stdin:
m = re.match(
r"\x1b\[35mflake8 \|\x1b\[0m \x1b\[1;31m(.+):(\d+):(\d+): (\w+)", msg
)
if m:
filename, row_str, col_str, err = m.groups()
row, col = int(row_str), int(col_str)
if filename == last_filename:
assert last_row != row
else:
if last_filename is not None:
with open(last_filename, "w") as f:
f.writelines(lines)
with open(filename) as f:
lines = f.readlines()
last_filename = filename
last_row = row
line = lines[row - 1]
if err in ["C812", "C815"]:
lines[row - 1] = line[: col - 1] + "," + line[col - 1 :]
elif err in ["C819"]:
assert line[col - 2] == ","
lines[row - 1] = line[: col - 2] + line[col - 1 :].lstrip(" ")
if last_filename is not None:
with open(last_filename, "w") as f:
f.writelines(lines)
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
Generated by pyupgrade --py36-plus --keep-percent-format, but with the
NamedTuple changes reverted (see commit
ba7906a3c6, #15132).
Signed-off-by: Anders Kaseorg <anders@zulip.com>
After subscribing a stream email address to a Mailman email list
and receiving a message from it (using the polling configuration
with an Exim + Dovecot mailserver), the following error message
is emitted by Zulip:
Logger zerver.lib.email_mirror, from module zerver.lib.email_mirror line 77:
Error generated by Anonymous user (not logged in) on zulip deployment
Sender: "Foo Bar" <foo@example.com>
To: No recipient found
Missing recipient in mirror email
This is because the To: header on the received email corresponds
to the email list, and there are no other headers to indicate the
final recipient, apart from the "Envelope-To" header added by
Exim. To resolve this problem, the commit adds "Envelope-To" to
the list of headers to check for a match.
type().__name__ is sufficient, and much readable than type(), so it's
better to use the former for keys.
We also make the classes consistent in forming the keys in the format
type(self).__name__:identifier and adjust logger.warning and statsd to
take advantage of that and simply log the key().
This is just a refactoring to the more modern API
for sending internal messages.
To make this work we now plumb the email_gateway
flag through `internal_send_stream_message` instead
of `internal_send_message`.
We also change `send_zulip` to have its callers
pass in a full UserProfile object (which one of
them already had).