apply most of linkxt review comments

chatmaild/src/chatmaild/filtermail.py

@@ -1,14 +1,12 @@
 #!/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.smtp import SMTP
-from aiosmtpd.controller import Controller
+from aiosmtpd.lmtp import LMTP
+from aiosmtpd.controller import UnixSocketController
 from smtplib import SMTP as SMTPClient
 
 
@@ -34,93 +32,94 @@ def check_encrypted(message):
     return True
 
 
-class SMTPController(Controller):
+class ExampleController(UnixSocketController):
     def factory(self):
-        return SMTP(self.handler, **self.SMTP_kwargs)
+        return LMTP(self.handler, **self.SMTP_kwargs)
 
 
-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}>"
-
+class ExampleHandler:
+    async def handle_RCPT(self, server, session, envelope, address, rcpt_options):
+        envelope.rcpt_tos.append(address)
         return "250 OK"
 
     async def handle_DATA(self, server, session, envelope):
-        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"
+        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)
 
 
-async def asyncmain_beforequeue(port):
-    Controller(BeforeQueueHandler(), hostname="127.0.0.1", port=port).start()
+async def asyncmain(loop):
+    controller = ExampleController(
+        ExampleHandler(), unix_socket="/var/spool/postfix/private/filtermail"
+    )
+    controller.start()
 
 
-def check_DATA(envelope):
+def lmtp_handle_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)
 
-    _, 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()
+    valid_recipients = []
+    res = []
     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
 
-        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}>"
+        recipient_local_domain = recipient.split("@")
+        if len(recipient_local_domain) != 2:
+            res += [f"500 Invalid address <{recipient}>"]
+            continue
 
+        is_outgoing = recipient_local_domain[1] != my_local_domain[1]
 
-class SendRateLimiter:
-    MAX_USER_SEND_PER_MINUTE = 80
+        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
 
-    def __init__(self):
-        self.addr2timestamps = {}
+        valid_recipients += [recipient]
+        res += ["250 OK"]
 
-    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
+    assert len(envelope.rcpt_tos) == len(res)
+    assert len(valid_recipients) <= len(res)
+    return valid_recipients, res
 
 
 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)
-    task = asyncmain_beforequeue(port=int(args[0]))
-    loop.create_task(task)
+    loop.create_task(asyncmain(loop=loop))
     loop.run_forever()
+
+
+if __name__ == "__main__":
+    main()

chatmaild/src/chatmaild/filtermail.service

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

chatmaild/src/chatmaild/test_filtermail.py

@@ -1,7 +1,6 @@
-from .filtermail import check_encrypted, check_DATA, SendRateLimiter
+from .filtermail import check_encrypted, lmtp_handle_DATA
 from email.parser import BytesParser
 from email import policy
-import pytest
 
 
 def test_reject_forged_from():
@@ -31,12 +30,15 @@ def test_reject_forged_from():
 
     # test that the filter lets good mail through
     envelope.content = makemail(envelope.mail_from).as_bytes()
-    assert not check_DATA(envelope=envelope)
+    valid_recipients, res = lmtp_handle_DATA(envelope=envelope)
+    assert valid_recipients == envelope.rcpt_tos
+    assert len(res) == 1 and "250" in res[0]
 
     # test that the filter rejects forged mail
     envelope.content = makemail("forged@c3.testrun.org").as_bytes()
-    error = check_DATA(envelope=envelope)
-    assert "500" in error
+    valid_recipients, res = lmtp_handle_DATA(envelope=envelope)
+    assert not valid_recipients
+    assert len(res) == 1 and "500" in res[0]
 
 
 def test_filtermail():
@@ -324,15 +326,3 @@ 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

deploy-chatmail/src/deploy_chatmail/__init__.py

@@ -34,28 +34,43 @@ def _install_chatmaild() -> None:
             commands=[f"pip install --break-system-packages {remote_path}"],
         )
 
-        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,
-            )
+        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,
+        )
 
 
 def _configure_opendkim(domain: str, dkim_selector: str) -> bool:
@@ -158,33 +173,6 @@ def _configure_dovecot(mail_server: str, debug: bool = False) -> bool:
     return need_restart
 
 
-def _configure_nginx(domain: str, debug: bool = False) -> bool:
-    """Configures nginx HTTP server."""
-    need_restart = False
-
-    main_config = files.template(
-        src=importlib.resources.files(__package__).joinpath("nginx.conf.j2"),
-        dest="/etc/nginx/nginx.conf",
-        user="root",
-        group="root",
-        mode="644",
-        config={"domain_name": domain},
-    )
-    need_restart |= main_config.changed
-
-    autoconfig = files.template(
-        src=importlib.resources.files(__package__).joinpath("autoconfig.xml.j2"),
-        dest="/var/www/html/.well-known/autoconfig/mail/config-v1.1.xml",
-        user="root",
-        group="root",
-        mode="644",
-        config={"domain_name": domain},
-    )
-    need_restart |= autoconfig.changed
-
-    return need_restart
-
-
 def deploy_chatmail(mail_domain: str, mail_server: str, dkim_selector: str) -> None:
     """Deploy a chat-mail instance.
 
@@ -206,7 +194,7 @@ def deploy_chatmail(mail_domain: str, mail_server: str, dkim_selector: str) -> N
     )
 
     # Deploy acmetool to have TLS certificates.
-    deploy_acmetool(nginx_hook=True, domains=[mail_server])
+    deploy_acmetool(domains=[mail_server])
 
     apt.packages(
         name="Install Postfix",
@@ -226,17 +214,11 @@ def deploy_chatmail(mail_domain: str, mail_server: str, dkim_selector: str) -> N
         ],
     )
 
-    apt.packages(
-        name="Install nginx",
-        packages=["nginx"],
-    )
-
     _install_chatmaild()
     debug = False
     dovecot_need_restart = _configure_dovecot(mail_server, debug=debug)
     postfix_need_restart = _configure_postfix(mail_domain, debug=debug)
     opendkim_need_restart = _configure_opendkim(mail_domain, dkim_selector)
-    nginx_need_restart = _configure_nginx(mail_domain)
 
     systemd.service(
         name="Start and enable OpenDKIM",
@@ -262,14 +244,6 @@ def deploy_chatmail(mail_domain: str, mail_server: str, dkim_selector: str) -> N
         restarted=dovecot_need_restart,
     )
 
-    systemd.service(
-        name="Start and enable nginx",
-        service="nginx.service",
-        running=True,
-        enabled=True,
-        restarted=nginx_need_restart,
-    )
-
     # This file is used by auth proxy.
     # https://wiki.debian.org/EtcMailName
     server.shell(

deploy-chatmail/src/deploy_chatmail/acmetool/__init__.py

@@ -38,13 +38,22 @@ def deploy_acmetool(nginx_hook=False, email="", domains=[]):
         email=email,
     )
 
-    files.template(
-        src=importlib.resources.files(__package__).joinpath("target.yaml.j2"),
-        dest="/var/lib/acme/conf/target",
+    service_file = files.put(
+        src=importlib.resources.files(__package__)
+        .joinpath("acmetool-redirector.service")
+        .open("rb"),
+        dest="/etc/systemd/system/acmetool-redirector.service",
         user="root",
         group="root",
         mode="644",
     )
+    systemd.service(
+        name="Setup acmetool-redirector service",
+        service="acmetool-redirector.service",
+        running=False,
+        enabled=False,
+        restarted=service_file.changed,
+    )
 
     for domain in domains:
         server.shell(

deploy-chatmail/src/deploy_chatmail/acmetool/acmetool-redirector.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=acmetool HTTP redirector
+
+[Service]
+Type=notify
+ExecStart=/usr/bin/acmetool redirector --service.uid=daemon
+Restart=always
+RestartSec=30
+
+[Install]
+WantedBy=multi-user.target

deploy-chatmail/src/deploy_chatmail/acmetool/target.yaml.j2

@@ -1,7 +0,0 @@
-request:
-  provider: https://acme-v02.api.letsencrypt.org/directory
-  key:
-    type: rsa
-  challenge:
-    webroot-paths:
-    - /var/www/html/.well-known/acme-challenge

deploy-chatmail/src/deploy_chatmail/autoconfig.xml.j2

@@ -1,37 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-
-<clientConfig version="1.1">
-  <emailProvider id="{{ config.domain_name }}">
-    <domain>{{ config.domain_name }}</domain>
-    <displayName>{{ config.domain_name }} chatmail</displayName>
-    <displayShortName>{{ config.domain_name }}</displayShortName>
-    <incomingServer type="imap">
-      <hostname>{{ config.domain_name }}</hostname>
-      <port>993</port>
-      <socketType>SSL</socketType>
-      <authentication>password-cleartext</authentication>
-      <username>%EMAILADDRESS%</username>
-    </incomingServer>
-    <incomingServer type="imap">
-      <hostname>{{ config.domain_name }}</hostname>
-      <port>143</port>
-      <socketType>STARTTLS</socketType>
-      <authentication>password-cleartext</authentication>
-      <username>%EMAILADDRESS%</username>
-    </incomingServer>
-    <outgoingServer type="smtp">
-      <hostname>{{ config.domain_name }}</hostname>
-      <port>465</port>
-      <socketType>SSL</socketType>
-      <authentication>password-cleartext</authentication>
-      <username>%EMAILADDRESS%</username>
-    </outgoingServer>
-    <outgoingServer type="smtp">
-      <hostname>{{ config.domain_name }}</hostname>
-      <port>587</port>
-      <socketType>STARTTLS</socketType>
-      <authentication>password-cleartext</authentication>
-      <username>%EMAILADDRESS%</username>
-    </outgoingServer>
-  </emailProvider>
-</clientConfig>

deploy-chatmail/src/deploy_chatmail/nginx.conf.j2

@@ -1,47 +0,0 @@
-user www-data;
-worker_processes auto;
-pid /run/nginx.pid;
-error_log /var/log/nginx/error.log;
-
-events {
-	worker_connections 768;
-	# multi_accept on;
-}
-
-http {
-	sendfile on;
-	tcp_nopush on;
-
-	# Do not emit nginx version on error pages.
-	server_tokens off;
-
-	include /etc/nginx/mime.types;
-	default_type application/octet-stream;
-
-	ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3;
-	ssl_prefer_server_ciphers on;
-	ssl_certificate /var/lib/acme/live/{{ config.domain_name }}/fullchain;
-	ssl_certificate_key /var/lib/acme/live/{{ config.domain_name }}/privkey;
-
-	gzip on;
-
-	server {
-		listen 80 default_server;
-		listen [::]:80 default_server;
-		listen 443 ssl default_server;
-		listen [::]:443 ssl default_server;
-
-		root /var/www/html;
-
-		index index.html index.htm;
-
-		server_name _;
-
-		location / {
-			# First attempt to serve request as file, then
-			# as directory, then fall back to displaying a 404.
-			try_files $uri $uri/ =404;
-		}
-	}
-}
-

deploy-chatmail/src/deploy_chatmail/postfix/master.cf.j2

@@ -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 smtpd_proxy_filter=127.0.0.1:10080
+  -o content_filter=filter:unix:private/filtermail
 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 smtpd_proxy_filter=127.0.0.1:10080
+  -o content_filter=filter:unix:private/filtermail
 #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:10025 inet  n       -       n       -       10      smtpd
+localhost:10026 inet  n       -       n       -       10      smtpd
         -o content_filter=

online-tests/test_0_basic.py

@@ -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, forgeaddr):
+def test_reject_forged_from(cmsetup, mailgen, lp, remote, forgeaddr):
     user1, user3 = cmsetup.gen_users(2)
 
     lp.sec("send encrypted message with forged from")
@@ -36,25 +36,17 @@ def test_reject_forged_from(cmsetup, mailgen, lp, forgeaddr):
         print(f"   {line}")
 
     lp.sec("Send forged mail and check remote postfix lmtp processing result")
-    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)
+    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")
 
-
-@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]
+    # 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:
             return
-    pytest.fail("Rate limit was not exceeded")
+    pytest.fail(f"forged From={addr_to_forge} did not cause non-delivery notice")

online-tests/test_0_login.py

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