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17 Commits

Author SHA1 Message Date
link2xt
15a9b4a2ef dictproxy: use crypt instead of doveadm pw 2023-10-20 08:30:36 +00:00
link2xt
902f98c9ba Set syslog name for reinject proxy 2023-10-19 03:22:27 +00:00
link2xt
89311063f8 Turn filtermail into a beforequeue handler and implement rate limit 2023-10-19 03:04:00 +00:00
link2xt
1cdc5d1351 Revert "open a persistent client between the BeforeQueueHandler and postfix smtpd without content filter"
This reverts commit fb2ea27477.
2023-10-19 02:22:38 +00:00
link2xt
30680cb170 filtermail: port is args[0], not args[1] 2023-10-19 02:22:30 +00:00
link2xt
c514fb00a3 Import SMTP from aiosmtpd.lmtp, not aiosmtpd.smtp 2023-10-19 02:22:15 +00:00
holger krekel
c7995356b9 shift for simpler diff 2023-10-19 01:16:19 +02:00
holger krekel
fb2ea27477 open a persistent client between the BeforeQueueHandler and postfix smtpd without content filter 2023-10-19 01:10:06 +02:00
holger krekel
7cf6cc2c91 remove filtermail split and LMTP backend 2023-10-19 01:05:49 +02:00
holger krekel
4358d5fe61 only do a smtp beforequeue-handler, also simplifies the send-rate-limiting test and improves DC behaviour 2023-10-19 00:54:45 +02:00
holger krekel
10cb099c0e all tests pass 2023-10-19 00:07:22 +02:00
link2xt
329b845c79 Configure journald to retain logs for 3 days 2023-10-18 22:54:50 +02:00
holger krekel
bbd2773506 refactor test and filtermail to prepare it for BeforeQueue handling 2023-10-18 21:43:06 +02:00
missytake
410bc50a8b test: report if rate limit from last test was still active 2023-10-18 19:02:40 +02:00
missytake
015269fa7b test: test that there is no internal limit (xfail for now) 2023-10-18 19:02:40 +02:00
missytake
b8673d8625 postfix: add simple rate limiting without allow list or leaky bucket, also for internal mail 2023-10-18 19:02:40 +02:00
missytake
31c71fa6e9 add test for postfix rate limiting 2023-10-18 19:02:40 +02:00
12 changed files with 177 additions and 223 deletions

View File

@@ -2,13 +2,13 @@ import logging
import os
import sys
import json
import crypt
from socketserver import (
UnixStreamServer,
StreamRequestHandler,
ThreadingMixIn,
)
import pwd
import subprocess
from .database import Database
@@ -16,17 +16,9 @@ NOCREATE_FILE = "/etc/chatmail-nocreate"
def encrypt_password(password: str):
password = password.encode("ascii")
# https://doc.dovecot.org/configuration_manual/authentication/password_schemes/
process = subprocess.Popen(
["doveadm", "pw", "-s", "SHA512-CRYPT"],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
)
stdout_data, _stderr_data = process.communicate(
input=password + b"\n" + password + b"\n"
)
return stdout_data.decode("ascii").strip()
passhash = crypt.crypt(password, crypt.METHOD_SHA512)
return "{SHA512-CRYPT}" + passhash
def create_user(db, user, password):

View File

@@ -1,12 +1,14 @@
#!/usr/bin/env python3
import asyncio
import logging
import time
import sys
from email.parser import BytesParser
from email import policy
from email.utils import parseaddr
from aiosmtpd.lmtp import LMTP
from aiosmtpd.controller import UnixSocketController
from aiosmtpd.smtp import SMTP
from aiosmtpd.controller import Controller
from smtplib import SMTP as SMTPClient
@@ -32,94 +34,93 @@ def check_encrypted(message):
return True
class ExampleController(UnixSocketController):
class SMTPController(Controller):
def factory(self):
return LMTP(self.handler, **self.SMTP_kwargs)
return SMTP(self.handler, **self.SMTP_kwargs)
class ExampleHandler:
async def handle_RCPT(self, server, session, envelope, address, rcpt_options):
envelope.rcpt_tos.append(address)
class BeforeQueueHandler:
def __init__(self):
self.send_rate_limiter = SendRateLimiter()
async def handle_MAIL(self, server, session, envelope, address, mail_options):
logging.info(f"handle_MAIL from {address}")
envelope.mail_from = address
if not self.send_rate_limiter.is_sending_allowed(address):
return f"450 4.7.1: Too much mail from {address}"
parts = envelope.mail_from.split("@")
if len(parts) != 2:
return f"500 Invalid from address <{envelope.mail_from!r}>"
return "250 OK"
async def handle_DATA(self, server, session, envelope):
valid_recipients, res = lmtp_handle_DATA(envelope)
# Reinject the mail back into Postfix.
if valid_recipients:
logging.info("Reinjecting the mail")
client = SMTPClient("localhost", "10026")
client.sendmail(envelope.mail_from, valid_recipients, envelope.content)
else:
logging.info("no valid recipients, ignoring mail")
return "\r\n".join(res)
logging.info("handle_DATA before-queue")
error = check_DATA(envelope)
if error:
return error
logging.info("re-injecting the mail that passed checks")
client = SMTPClient("localhost", "10025")
client.sendmail(envelope.mail_from, envelope.rcpt_tos, envelope.content)
return "250 OK"
async def asyncmain(loop):
controller = ExampleController(
ExampleHandler(), unix_socket="/var/spool/postfix/private/filtermail"
)
controller.start()
async def asyncmain_beforequeue(port):
Controller(BeforeQueueHandler(), hostname="127.0.0.1", port=port).start()
def lmtp_handle_DATA(envelope):
def check_DATA(envelope):
"""the central filtering function for e-mails."""
logging.info(f"Processing DATA message from {envelope.mail_from}")
message = BytesParser(policy=policy.default).parsebytes(envelope.content)
mail_encrypted = check_encrypted(message)
valid_recipients = []
res = []
_, from_addr = parseaddr(message.get("from").strip())
logging.info(f"mime-from: {from_addr} envelope-from: {envelope.mail_from!r}")
if envelope.mail_from.lower() != from_addr.lower():
return f"500 Invalid FROM <{from_addr!r}> for <{envelope.mail_from!r}>"
envelope_from_domain = from_addr.split("@").pop()
for recipient in envelope.rcpt_tos:
my_local_domain = envelope.mail_from.split("@")
if len(my_local_domain) != 2:
res += [f"500 Invalid from address <{envelope.mail_from}>"]
continue
_, from_addr = parseaddr(message.get("from").strip())
logging.info(f"mime-from: {from_addr} envelope-from: {envelope.mail_from}")
if envelope.mail_from.lower() != from_addr.lower():
res += [f"500 Invalid FROM <{from_addr}> for <{envelope.mail_from}>"]
continue
if envelope.mail_from == recipient:
# Always allow sending emails to self.
valid_recipients += [recipient]
res += ["250 OK"]
continue
res = recipient.split("@")
if len(res) != 2:
return f"500 Invalid address <{recipient}>"
_recipient_addr, recipient_domain = res
recipient_local_domain = recipient.split("@")
if len(recipient_local_domain) != 2:
res += [f"500 Invalid address <{recipient}>"]
continue
is_outgoing = recipient_domain != envelope_from_domain
if is_outgoing and not mail_encrypted:
is_securejoin = message.get("secure-join") in ["vc-request", "vg-request"]
if not is_securejoin:
return f"500 Invalid unencrypted mail to <{recipient}>"
is_outgoing = recipient_local_domain[1] != my_local_domain[1]
if (
is_outgoing
and not mail_encrypted
and message.get("secure-join") != "vc-request"
and message.get("secure-join") != "vg-request"
):
res += ["500 Outgoing mail must be encrypted"]
continue
class SendRateLimiter:
MAX_USER_SEND_PER_MINUTE = 80
valid_recipients += [recipient]
res += ["250 OK"]
def __init__(self):
self.addr2timestamps = {}
assert len(envelope.rcpt_tos) == len(res)
assert len(valid_recipients) <= len(res)
return valid_recipients, res
def is_sending_allowed(self, mail_from):
last = self.addr2timestamps.setdefault(mail_from, [])
now = time.time()
last[:] = [ts for ts in last if ts >= (now - 60)]
if len(last) <= self.MAX_USER_SEND_PER_MINUTE:
last.append(now)
return True
return False
def main():
args = sys.argv[1:]
assert len(args) == 1
logging.basicConfig(level=logging.INFO)
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
loop.create_task(asyncmain(loop=loop))
task = asyncmain_beforequeue(port=int(args[0]))
loop.create_task(task)
loop.run_forever()
if __name__ == "__main__":
main()

View File

@@ -1,8 +1,8 @@
[Unit]
Description=Email filter for chatmail servers
Description=Chatmail Postfix BeforeQeue filter
[Service]
ExecStart=/usr/local/bin/filtermail
ExecStart=/usr/local/bin/filtermail 10080
Restart=always
RestartSec=30

View File

@@ -1,6 +1,7 @@
from .filtermail import check_encrypted, lmtp_handle_DATA
from .filtermail import check_encrypted, check_DATA, SendRateLimiter
from email.parser import BytesParser
from email import policy
import pytest
def test_reject_forged_from():
@@ -30,15 +31,12 @@ def test_reject_forged_from():
# test that the filter lets good mail through
envelope.content = makemail(envelope.mail_from).as_bytes()
valid_recipients, res = lmtp_handle_DATA(envelope=envelope)
assert valid_recipients == envelope.rcpt_tos
assert len(res) == 1 and "250" in res[0]
assert not check_DATA(envelope=envelope)
# test that the filter rejects forged mail
envelope.content = makemail("forged@c3.testrun.org").as_bytes()
valid_recipients, res = lmtp_handle_DATA(envelope=envelope)
assert not valid_recipients
assert len(res) == 1 and "500" in res[0]
error = check_DATA(envelope=envelope)
assert "500" in error
def test_filtermail():
@@ -326,3 +324,15 @@ def test_filtermail():
]
).encode()
)
def test_send_rate_limiter():
limiter = SendRateLimiter()
for i in range(100):
if limiter.is_sending_allowed("some@example.org"):
if i <= SendRateLimiter.MAX_USER_SEND_PER_MINUTE:
continue
pytest.fail("limiter didn't work")
else:
assert i == SendRateLimiter.MAX_USER_SEND_PER_MINUTE + 1
break

View File

@@ -34,43 +34,28 @@ def _install_chatmaild() -> None:
commands=[f"pip install --break-system-packages {remote_path}"],
)
files.put(
name="upload doveauth-dictproxy.service",
src=importlib.resources.files("chatmaild")
.joinpath("doveauth-dictproxy.service")
.open("rb"),
dest="/etc/systemd/system/doveauth-dictproxy.service",
user="root",
group="root",
mode="644",
)
systemd.service(
name="Setup doveauth-dictproxy service",
service="doveauth-dictproxy.service",
running=True,
enabled=True,
restarted=True,
daemon_reload=True,
)
files.put(
name="upload filtermail.service",
src=importlib.resources.files("chatmaild")
.joinpath("filtermail.service")
.open("rb"),
dest="/etc/systemd/system/filtermail.service",
user="root",
group="root",
mode="644",
)
systemd.service(
name="Setup filtermail service",
service="filtermail.service",
running=True,
enabled=True,
restarted=True,
daemon_reload=True,
)
for fn in (
"doveauth-dictproxy",
"filtermail",
):
files.put(
name=f"Upload {fn}.service",
src=importlib.resources.files("chatmaild")
.joinpath(f"{fn}.service")
.open("rb"),
dest=f"/etc/systemd/system/{fn}.service",
user="root",
group="root",
mode="644",
)
systemd.service(
name=f"Setup {fn} service",
service=f"{fn}.service",
running=True,
enabled=True,
restarted=True,
daemon_reload=True,
)
def _configure_opendkim(domain: str, dkim_selector: str) -> bool:
@@ -292,6 +277,22 @@ def deploy_chatmail(mail_domain: str, mail_server: str, dkim_selector: str) -> N
commands=[f"echo {mail_domain} >/etc/mailname; chmod 644 /etc/mailname"],
)
journald_conf = files.put(
name="Configure journald",
src=importlib.resources.files(__package__).joinpath("journald.conf"),
dest="/etc/systemd/journald.conf",
user="root",
group="root",
mode="644",
)
systemd.service(
name="Start and enable journald",
service="systemd-journald.service",
running=True,
enabled=True,
restarted=journald_conf,
)
def callback():
result = server.shell(
commands=[

View File

@@ -0,0 +1,2 @@
[Journal]
MaxRetentionSec=3d

View File

@@ -32,7 +32,7 @@ submission inet n - y - - smtpd
-o smtpd_recipient_restrictions=
-o smtpd_relay_restrictions=permit_sasl_authenticated,reject
-o milter_macro_daemon_name=ORIGINATING
-o content_filter=filter:unix:private/filtermail
-o smtpd_proxy_filter=127.0.0.1:10080
smtps inet n - y - - smtpd
-o syslog_name=postfix/smtps
-o smtpd_tls_wrappermode=yes
@@ -47,7 +47,7 @@ smtps inet n - y - - smtpd
-o smtpd_recipient_restrictions=
-o smtpd_relay_restrictions=permit_sasl_authenticated,reject
-o milter_macro_daemon_name=ORIGINATING
-o content_filter=filter:unix:private/filtermail
-o smtpd_proxy_filter=127.0.0.1:10080
#628 inet n - y - - qmqpd
pickup unix n - y 60 1 pickup
cleanup unix n - y - 0 cleanup
@@ -76,5 +76,5 @@ scache unix - - y - 1 scache
postlog unix-dgram n - n - 1 postlogd
filter unix - n n - - lmtp
# Local SMTP server for reinjecting filered mail.
localhost:10026 inet n - n - 10 smtpd
-o content_filter=
localhost:10025 inet n - n - 10 smtpd
-o syslog_name=postfix/reinject

View File

@@ -1,60 +1,34 @@
def test_tls_imap(benchmark, imap):
def imap_connect():
imap.connect()
def test_tls_serialized_connect(benchmark, imap_or_smtp):
def connect():
imap_or_smtp.connect()
benchmark(imap_connect, 10)
benchmark(connect)
def test_login_imap(benchmark, imap, gencreds):
def imap_connect_and_login():
imap.connect()
imap.login(*gencreds())
def test_login(benchmark, imap_or_smtp, gencreds):
cls = imap_or_smtp.__class__
conns = []
for i in range(20):
conn = cls(imap_or_smtp.host)
conn.connect()
conns.append(conn)
benchmark(imap_connect_and_login, 10)
def login():
conn = conns.pop()
conn.login(*gencreds())
benchmark(login)
def test_tls_smtp(benchmark, smtp):
def smtp_connect():
smtp.connect()
def test_send_and_receive_10(benchmark, cmfactory, lp):
"""send many messages between two accounts"""
ac1, ac2 = cmfactory.get_online_accounts(2)
chat = cmfactory.get_accepted_chat(ac1, ac2)
benchmark(smtp_connect, 10)
def send_10_receive_all():
for i in range(10):
chat.send_text(f"hello {i}")
for i in range(10):
ac2.wait_next_incoming_message()
def test_login_smtp(benchmark, smtp, gencreds):
def smtp_connect_and_login():
smtp.connect()
smtp.login(*gencreds())
benchmark(smtp_connect_and_login, 10)
class TestDC:
def test_autoconfigure(self, benchmark, cmfactory):
def autoconfig_and_idle_ready():
cmfactory.get_online_accounts(1)
benchmark(autoconfig_and_idle_ready, 5)
def test_ping_pong(self, benchmark, cmfactory):
ac1, ac2 = cmfactory.get_online_accounts(2)
chat = cmfactory.get_accepted_chat(ac1, ac2)
def ping_pong():
chat.send_text("ping")
msg = ac2.wait_next_incoming_message()
msg.chat.send_text("pong")
ac1.wait_next_incoming_message()
benchmark(ping_pong, 3)
def test_send_10_receive_10(self, benchmark, cmfactory, lp):
ac1, ac2 = cmfactory.get_online_accounts(2)
chat = cmfactory.get_accepted_chat(ac1, ac2)
def send_10_receive_10():
for i in range(10):
chat.send_text(f"hello {i}")
for i in range(10):
ac2.wait_next_incoming_message()
benchmark(send_10_receive_10, 1)
benchmark(send_10_receive_all)

View File

@@ -1,6 +1,5 @@
import os
import io
import time
import random
import subprocess
import imaplib
@@ -15,10 +14,6 @@ def pytest_addoption(parser):
)
def pytest_configure(config):
config._benchresults = {}
def pytest_runtest_setup(item):
markers = list(item.iter_markers(name="slow"))
if markers:
@@ -59,35 +54,6 @@ def pytest_report_header():
return ["-" * len(text), text, "-" * len(text)]
@pytest.fixture
def benchmark(request):
def bench(func, num, name=None):
if name is None:
name = func.__name__
durations = []
for i in range(num):
now = time.time()
func()
durations.append(time.time() - now)
durations.sort()
request.config._benchresults[name] = durations
return bench
def pytest_terminal_summary(terminalreporter):
tr = terminalreporter
results = tr.config._benchresults
tr.section("benchmark results")
headers = f"{'benchmark name': <30} {'median': >6}"
tr.write_line(headers)
tr.write_line("-" * len(headers))
for name, durations in results.items():
median = sorted(durations)[len(durations) // 2]
median = f"{median:2.4f}"
tr.write_line(f"{name: <30} {median: >6}")
@pytest.fixture
def imap(maildomain):
return ImapConn(maildomain)

View File

@@ -20,7 +20,7 @@ def test_use_two_chatmailservers(cmfactory, maildomain2):
@pytest.mark.parametrize("forgeaddr", ["internal", "someone@example.org"])
def test_reject_forged_from(cmsetup, mailgen, lp, remote, forgeaddr):
def test_reject_forged_from(cmsetup, mailgen, lp, forgeaddr):
user1, user3 = cmsetup.gen_users(2)
lp.sec("send encrypted message with forged from")
@@ -36,17 +36,25 @@ def test_reject_forged_from(cmsetup, mailgen, lp, remote, forgeaddr):
print(f" {line}")
lp.sec("Send forged mail and check remote postfix lmtp processing result")
remote_log = remote.iter_output("journalctl -t postfix/lmtp")
user1.smtp.sendmail(from_addr=user1.addr, to_addrs=[user3.addr], msg=msg)
for line in remote_log:
# print(line)
if "500 invalid from" in line and user3.addr in line:
break
else:
pytest.fail("remote postfix/filtermail failed to reject message")
with pytest.raises(smtplib.SMTPException) as e:
user1.smtp.sendmail(from_addr=user1.addr, to_addrs=[user3.addr], msg=msg)
assert "500" in str(e.value)
# check that the logged in user (who sent the forged msg) got a non-delivery notice
for message in user1.imap.fetch_all_messages():
if "Invalid FROM" in message and addr_to_forge in message:
@pytest.mark.slow
def test_exceed_rate_limit(cmsetup, gencreds, mailgen):
"""Test that the per-account send-mail limit is exceeded."""
user1, user2 = cmsetup.gen_users(2)
mail = mailgen.get_encrypted(user1.addr, user2.addr)
for i in range(100):
print("Sending mail", str(i))
try:
user1.smtp.sendmail(user1.addr, [user2.addr], mail)
except smtplib.SMTPException as e:
if i < 80:
pytest.fail(f"rate limit was exceeded too early with msg {i}")
outcome = e.recipients[user2.addr]
assert outcome[0] == 450
assert b'4.7.1: Too much mail from' in outcome[1]
return
pytest.fail(f"forged From={addr_to_forge} did not cause non-delivery notice")
pytest.fail("Rate limit was not exceeded")

View File

@@ -1,4 +1,5 @@
import pytest
import smtplib
def test_login_basic_functioning(imap_or_smtp, gencreds, lp):

View File

@@ -6,9 +6,8 @@ deploy-chatmail/venv/bin/pip install -e deploy-chatmail
deploy-chatmail/venv/bin/pip install -e chatmaild
python3 -m venv chatmaild/venv
sudo apt install -y dovecot-core && sudo systemctl disable --now dovecot
chatmaild/venv/bin/pip install --upgrade pytest build 'setuptools>=68'
chatmaild/venv/bin/pip install -e chatmaild
python3 -m venv online-tests/venv
online-tests/venv/bin/pip install pytest pytest-timeout pdbpp deltachat
online-tests/venv/bin/pip install pytest pytest-timeout pdbpp deltachat pytest-benchmark