Commit graph

64 commits

Author SHA1 Message Date
Mechiel Lukkien
54981fbc93
add a todo for preventing message content from being logged on common imap append to Sent 2023-02-22 10:43:21 +01:00
Mechiel Lukkien
fb3794e31b
only send \NonExistent for IMAP4rev2, and automatically subscribe to imported mailboxes 2023-02-17 18:35:11 +01:00
Mechiel Lukkien
5c33640aea
consistently use log.Check for logging errors that "should not happen", don't influence application flow
sooner or later, someone will notice one of these messages, which will lead us
to a bug.
2023-02-16 13:22:00 +01:00
Mechiel Lukkien
5336032088
add funtionality to import zip/tgz with maildirs/mboxes to account page
so users can easily take their email out of somewhere else, and import it into mox.

this goes a little way to give feedback as the import progresses: upload
progress is shown (surprisingly, browsers aren't doing this...), imported
mailboxes/messages are counted (batched) and import issues/warnings are
displayed, all sent over an SSE connection. an import token is stored in
sessionstorage. if you reload the page (e.g. after a connection error), the
browser will reconnect to the running import and show its progress again. and
you can just abort the import before it is finished and committed, and nothing
will have changed.

this also imports flags/keywords from mbox files.
2023-02-16 09:57:27 +01:00
Mechiel Lukkien
ad51ffc365
make account web page configurable separately from admin, add http auth rate limiting
ideally both account & admin web pages should be on non-public ips (e.g. a
wireguard tunnel). but during setup, users may not have that set up, and they
may want to configure the admin/account pages on their public ip's. the auth
rate limiting should make it less of issue.

users can now also only put the account web page publicly available. useful for
if you're the admin and you have a vpn connection, but your other/external
users do not have a vpn into your mail server. to make the account page more
easily findable, the http root serves the account page. the admin page is still
at /admin/, to prevent clash with potential account pages, but if no account
page is present, you are helpfully redirected from / to /admin/.

this also adds a prometheus metric counting how often auth attempts have been
rate limited.
2023-02-13 13:53:47 +01:00
Mechiel Lukkien
87854cfde3
change some log levels from info to debug, and use lower case log messages 2023-02-11 23:54:22 +01:00
Mechiel Lukkien
bf04fb8a1a
improve training of junk filter
before, we used heuristics to decide when to train/untrain a message as junk or
nonjunk: the message had to be seen, be in certain mailboxes. then if a message
was marked as junk, it was junk. and otherwise it was nonjunk. this wasn't good
enough: you may want to keep some messages around as neither junk or nonjunk.
and that wasn't possible.

ideally, we would just look at the imap $Junk and $NotJunk flags. the problem
is that mail clients don't set these flags, or don't make it easy. thunderbird
can set the flags based on its own bayesian filter. it has a shortcut for
marking Junk and moving it to the junk folder (good), but the counterpart of
notjunk only marks a message as notjunk without showing in the UI that it was
marked as notjunk. there is also no "move and mark as notjunk" mechanism. e.g.
"archive" does not mark a message as notjunk. ios mail and mutt don't appear to
have any way to see or change the $Junk and $NotJunk flags.

what email clients do have is the ability to move messages to other
mailboxes/folders. so mox now has a mechanism that allows you to configure
mailboxes that automatically set $Junk or $NotJunk (or clear both) when a
message is moved/copied/delivered to that folder. e.g. a mailbox called junk or
spam or rejects marks its messags as junk. inbox, postmaster, dmarc, tlsrpt,
neutral* mark their messages as neither junk or notjunk. other folders mark
their messages as notjunk. e.g. list/*, archive. this functionality is
optional, but enabled with the quickstart and for new accounts.

also, mox now keeps track of the previous training of a message and will only
untrain/train if needed. before, there probably have been duplicate or missing
(un)trainings.

this also includes a new subcommand "retrain" to recreate the junkfilter for an
account. you should run it after updating to this version. and you should
probably also modify your account config to include the AutomaticJunkFlags.
2023-02-11 23:00:12 +01:00
Mechiel Lukkien
9419ee15dd
slow down connections for spammy deliveries, and too many failed authentications, and sleep for 15 seconds before delivering messages by first-time senders
similar to greylisting, but not quite the same: with greylisting you would
always reject the first delivery attempt with a temporary failure. with the
hope that spammers won't retry their deliveries. the spams i've been receiving
seem to be quite consistent though. and we would keep rejecting them anyway.

we slow down the spammy connections to waste some of the resources of a
spammer. this may slow their campaigns down a bit, leaving a bit more time to
take measures.

we do the same with connections that have their 3rd authentication failure,
typically password guess attempts.

when we accept a message by a first-time sender, we sleep for 15 seconds before
actually delivering them. known-good senders don't have to wait. if the message
turns out to be a spammer, at least we've consumed one of their connections,
and they cannot deliver at too high a rate to us because of the max open
connection limit.
2023-02-08 21:45:32 +01:00
Mechiel Lukkien
2154392bd8
add basic rate limiters
limiting is done based on remote ip's, with 3 ip mask variants to limit networks
of machines. often with two windows, enabling short bursts of activity, but not
sustained high activity. currently only for imap and smtp, not yet http.

limits are currently based on:
- number of open connections
- connection rate
- limits after authentication failures. too many failures, and new connections will be dropped.
- rate of delivery in total number of messages
- rate of delivery in total size of messages

the limits on connections and authentication failures are in-memory. the limits
on delivery of messages are based on stored messages.

the limits themselves are not yet configurable, let's use this first.

in the future, we may also want to have stricter limits for senders without any
reputation.
2023-02-07 23:18:15 +01:00
Mechiel Lukkien
e52c9d36a6
support cram-md5 authentication for imap and smtp
and change thunderbird autoconfiguration to use it.

unfortunately, for microsoft autodiscover, there appears to be no way to
request secure password negotiation. so it will default to plain text auth.

cram-md5 is less secure than scram-sha-*, but thunderbird does not yet support
scram auth. it currently chooses "plain", sending the literal password over the
connection (which is TLS-protected, but we don't want to receive clear text
passwords). in short, cram-md5 is better than nothing...

for cram-md5 to work, a new set of derived credentials need to be stored in the
database. so you need to save your password again to make it work. this was
also the case with the scram-sha-1 addition, but i forgot to mention it then.
2023-02-05 16:29:03 +01:00
Mechiel Lukkien
642a328ae1
add support for SCRAM-SHA-1
the idea is that clients may not support SCRAM-SHA-256, but may support
SCRAM-SHA-1. if they do support the 256 variant, they'll use it.

unfortunately, thunderbird does not support scram-sha-1 either.
2023-02-05 12:30:14 +01:00
Mechiel Lukkien
ffb2a10a4e
add two new log levels for tracing sensitive auth protocol messages, and bulk data messages
named "traceauth" and "tracedata".

with this, you can (almost) enable trace logging without fear of logging
sensitive data or ddos'ing your log server.

the caveat is that the imap login command has already printed the line as
regular trace before we can decide it should not be. can be fixed soon.
2023-02-03 20:33:19 +01:00
Mechiel Lukkien
020d0bb0fb
add scram-sha-256 for smtp
similar to imap. the code should be merged.
this also reads the abort-line after authentication failure.
2023-01-31 00:22:26 +01:00
Mechiel Lukkien
cb229cb6cf
mox! 2023-01-30 14:27:06 +01:00