Merge 'rspamd' branch, replacing OpenDKIM with rspamd

This adds DKIM and SPF checks and replaces OpenDKIM with rspamd for
DKIM signing.
This commit is contained in:
link2xt 2024-01-14 09:30:31 +00:00
commit 8cdf8ce376
10 changed files with 171 additions and 92 deletions

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@ -7,7 +7,7 @@ Date: Sun, 15 Oct 2023 16:41:44 +0000
Message-ID: <Mr.3gckbNy5bch.uK3Hd2Ws6-w@c2.testrun.org>
References: <Mr.3gckbNy5bch.uK3Hd2Ws6-w@c2.testrun.org>
Chat-Version: 1.0
Autocrypt: addr=foobar@c2.testrun.org; prefer-encrypt=mutual;
Autocrypt: addr={from_addr}; prefer-encrypt=mutual;
keydata=xjMEZSrw3hYJKwYBBAHaRw8BAQdAiEKNQFU28c6qsx4vo/JHdt73RXdjMOmByf/XsGiJ7m
nNFzxmb29iYXJAYzIudGVzdHJ1bi5vcmc+wosEEBYIADMCGQEFAmUq8N4CGwMECwkIBwYVCAkKCwID
FgIBFiEEGil0OvTIa6RngmCLUYNnEa9leJAACgkQUYNnEa9leJCX3gEAhm0MehE5byBBU1avPczr/I

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@ -126,71 +126,6 @@ def _install_remote_venv_with_chatmaild(config) -> None:
)
def _configure_opendkim(domain: str, dkim_selector: str = "dkim") -> bool:
"""Configures OpenDKIM"""
need_restart = False
main_config = files.template(
src=importlib.resources.files(__package__).joinpath("opendkim/opendkim.conf"),
dest="/etc/opendkim.conf",
user="root",
group="root",
mode="644",
config={"domain_name": domain, "opendkim_selector": dkim_selector},
)
need_restart |= main_config.changed
files.directory(
name="Add opendkim directory to /etc",
path="/etc/opendkim",
user="opendkim",
group="opendkim",
mode="750",
present=True,
)
keytable = files.template(
src=importlib.resources.files(__package__).joinpath("opendkim/KeyTable"),
dest="/etc/dkimkeys/KeyTable",
user="opendkim",
group="opendkim",
mode="644",
config={"domain_name": domain, "opendkim_selector": dkim_selector},
)
need_restart |= keytable.changed
signing_table = files.template(
src=importlib.resources.files(__package__).joinpath("opendkim/SigningTable"),
dest="/etc/dkimkeys/SigningTable",
user="opendkim",
group="opendkim",
mode="644",
config={"domain_name": domain, "opendkim_selector": dkim_selector},
)
need_restart |= signing_table.changed
files.directory(
name="Add opendkim socket directory to /var/spool/postfix",
path="/var/spool/postfix/opendkim",
user="opendkim",
group="opendkim",
mode="750",
present=True,
)
if not host.get_fact(File, f"/etc/dkimkeys/{dkim_selector}.private"):
server.shell(
name="Generate OpenDKIM domain keys",
commands=[
f"opendkim-genkey -D /etc/dkimkeys -d {domain} -s {dkim_selector}"
],
_sudo=True,
_sudo_user="opendkim",
)
return need_restart
def _install_mta_sts_daemon() -> bool:
need_restart = False
@ -370,6 +305,107 @@ def _configure_nginx(domain: str, debug: bool = False) -> bool:
return need_restart
def remove_opendkim() -> None:
"""Remove OpenDKIM, deprecated"""
files.file(
name="Remove legacy opendkim.conf",
path="/etc/opendkim.conf",
present=False,
)
files.directory(
name="Remove legacy opendkim socket directory from /var/spool/postfix",
path="/var/spool/postfix/opendkim",
present=False,
)
apt.packages(name="Remove openDKIM", packages="opendkim", present=False)
def _configure_rspamd(dkim_selector: str, mail_domain: str) -> bool:
"""Configures rspamd for Rate Limiting."""
need_restart = False
apt.packages(
name="apt install rspamd",
packages="rspamd",
)
for module in ["phishing", "rbl", "hfilter", "ratelimit"]:
disabled_module_conf = files.put(
name=f"disable {module} rspamd plugin",
src=importlib.resources.files(__package__).joinpath("rspamd/disabled.conf"),
dest=f"/etc/rspamd/local.d/{module}.conf",
user="root",
group="root",
mode="644",
)
need_restart |= disabled_module_conf.changed
options_inc = files.put(
name="disable fuzzy checks",
src=importlib.resources.files(__package__).joinpath("rspamd/options.inc"),
dest="/etc/rspamd/local.d/options.inc",
user="root",
group="root",
mode="644",
)
need_restart |= options_inc.changed
# https://rspamd.com/doc/modules/force_actions.html
force_actions_conf = files.put(
name="Set up rules to reject on DKIM, SPF and DMARC fails",
src=importlib.resources.files(__package__).joinpath(
"rspamd/force_actions.conf"
),
dest="/etc/rspamd/local.d/force_actions.conf",
user="root",
group="root",
mode="644",
)
need_restart |= force_actions_conf.changed
dkim_directory = "/var/lib/rspamd/dkim/"
dkim_key_path = f"{dkim_directory}{mail_domain}.{dkim_selector}.key"
dkim_dns_file = f"{dkim_directory}{mail_domain}.{dkim_selector}.zone"
dkim_config = files.template(
src=importlib.resources.files(__package__).joinpath(
"rspamd/dkim_signing.conf.j2"
),
dest="/etc/rspamd/local.d/dkim_signing.conf",
user="root",
group="root",
mode="644",
config={
"dkim_selector": str(dkim_selector),
"mail_domain": mail_domain,
"dkim_key_path": dkim_key_path,
},
)
need_restart |= dkim_config.changed
files.directory(
name="ensure DKIM key directory exists",
path=dkim_directory,
present=True,
user="_rspamd",
group="_rspamd",
)
if not host.get_fact(File, dkim_key_path):
server.shell(
name="Generate DKIM domain keys with rspamd",
commands=[
f"rspamadm dkim_keygen -b 2048 -s {dkim_selector} -d {mail_domain} -k {dkim_key_path} > {dkim_dns_file}"
],
_sudo=True,
_sudo_user="_rspamd",
)
return need_restart
def check_config(config):
mail_domain = config.mail_domain
if mail_domain != "testrun.org" and not mail_domain.endswith(".testrun.org"):
@ -397,14 +433,6 @@ def deploy_chatmail(config_path: Path) -> None:
server.group(name="Create vmail group", group="vmail", system=True)
server.user(name="Create vmail user", user="vmail", group="vmail", system=True)
server.group(name="Create opendkim group", group="opendkim", system=True)
server.user(
name="Add postfix user to opendkim group for socket access",
user="postfix",
groups=["opendkim"],
system=True,
)
# Run local DNS resolver `unbound`.
# `resolvconf` takes care of setting up /etc/resolv.conf
# to use 127.0.0.1 as the resolver.
@ -439,14 +467,6 @@ def deploy_chatmail(config_path: Path) -> None:
packages=["dovecot-imapd", "dovecot-lmtpd"],
)
apt.packages(
name="Install OpenDKIM",
packages=[
"opendkim",
"opendkim-tools",
],
)
apt.packages(
name="Install nginx",
packages=["nginx"],
@ -468,16 +488,18 @@ def deploy_chatmail(config_path: Path) -> None:
debug = False
dovecot_need_restart = _configure_dovecot(config, debug=debug)
postfix_need_restart = _configure_postfix(config, debug=debug)
opendkim_need_restart = _configure_opendkim(mail_domain)
mta_sts_need_restart = _install_mta_sts_daemon()
nginx_need_restart = _configure_nginx(mail_domain)
remove_opendkim()
rspamd_need_restart = _configure_rspamd("dkim", mail_domain)
systemd.service(
name="Start and enable OpenDKIM",
service="opendkim.service",
name="Start and enable rspamd",
service="rspamd.service",
running=True,
enabled=True,
restarted=opendkim_need_restart,
restarted=rspamd_need_restart,
)
systemd.service(

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@ -7,7 +7,7 @@ _imap._tcp.{chatmail_domain}. SRV 0 1 143 {chatmail_domain}.
_imaps._tcp.{chatmail_domain}. SRV 0 1 993 {chatmail_domain}.
{chatmail_domain}. CAA 128 issue "letsencrypt.org;accounturi={acme_account_url}"
{chatmail_domain}. TXT "v=spf1 a:{chatmail_domain} -all"
_dmarc.{chatmail_domain}. TXT "v=DMARC1;p=reject;rua=mailto:{email};ruf=mailto:{email};fo=1;adkim=r;aspf=r"
_dmarc.{chatmail_domain}. TXT "v=DMARC1;p=reject;rua=mailto:{email};ruf=mailto:{email};fo=1;adkim=s;aspf=s"
_mta-sts.{chatmail_domain}. TXT "v=STSv1; id={sts_id}"
mta-sts.{chatmail_domain}. CNAME {chatmail_domain}.
www.{chatmail_domain}. CNAME {chatmail_domain}.

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@ -60,6 +60,9 @@ def show_dns(args, out):
continue
line = line.replace("\t", " ")
lines.append(line)
lines[0] = f"dkim._domainkey.{mail_domain}. IN TXT " + lines[0].strip(
"dkim._domainkey IN TXT "
)
return "\n".join(lines)
print("Checking your DKIM keys and DNS entries...")
@ -68,7 +71,9 @@ def show_dns(args, out):
except subprocess.CalledProcessError:
print("Please run `cmdeploy run` first.")
return
dkim_entry = read_dkim_entries(out.shell_output(f"{ssh} -- opendkim-genzone -F"))
dkim_entry = read_dkim_entries(
out.shell_output(f"{ssh} -- cat /var/lib/rspamd/dkim/{mail_domain}.dkim.zone")
)
ipv6 = dns.get_ipv6()
reverse_ipv6 = dns.check_ptr_record(ipv6, mail_domain)
@ -142,8 +147,8 @@ def show_dns(args, out):
domain, data = "\n".join(dkim_lines).split(" IN TXT ")
current = dns.get("TXT", domain.strip()[:-1])
if current:
current = "( %s )" % (current.replace('" "', '"\n "'))
if current.replace(";", "\\;") != data:
current = "( %s" % (current.replace('" "', '"\n "'))
if current != data:
to_print.append(dkim_entry)
else:
to_print.append(dkim_entry)

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@ -46,7 +46,7 @@ inet_protocols = all
virtual_transport = lmtp:unix:private/dovecot-lmtp
virtual_mailbox_domains = {{ config.mail_domain }}
smtpd_milters = unix:opendkim/opendkim.sock
smtpd_milters = inet:127.0.0.1:11332
non_smtpd_milters = $smtpd_milters
header_checks = regexp:/etc/postfix/submission_header_cleanup

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@ -0,0 +1 @@
enabled = false;

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@ -0,0 +1,10 @@
selector = {{ config.dkim_selector }}
use_esld = false # don't cut c1.testrun.org down to testrun.org
domain = {
{{ config.mail_domain }} {
selectors [
selector = {{ config.dkim_selector }}
path = {{ config.dkim_key_path }}
]
}
}

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@ -0,0 +1,30 @@
rules {
REJECT_DKIM_SPF {
action = "reject";
# Reject if
# - R_DKIM_RJECT: DKIM reject inserted by `dkim` module.
# - R_DKIM_PERMFAIL: permanent failure inserted by `dkim` module e.g. no DKIM DNS record found.
# - No DKIM signing (R_DKIM_NA symbol inserted by `dkim` module)
#
# - SPF failure (R_SPF_FAIL)
# - SPF permanent failure, e.g. failed to resolve DNS record referenced from SPF (R_SPF_PERMFAIL)
#
# - DMARC policy failure (DMARC_POLICY_REJECT)
#
# Do not reject if:
# - R_DKIM_TEMPFAIL, it is a DNS resolution failure
# and we do not want to lose messages because of faulty network.
#
# - R_SPF_SOFTFAIL
# - R_SPF_NEUTRAL
# - R_SPF_DNSFAIL
# - R_SPF_NA
#
# - DMARC_DNSFAIL
# - DMARC_NA
# - DMARC_POLICY_SOFTFAIL
# - DMARC_POLICY_QUARANTINE
# - DMARC_BAD_POLICY
expression = "R_DKIM_REJECT | R_DKIM_PERMFAIL | R_DKIM_NA | R_SPF_FAIL | R_SPF_PERMFAIL | DMARC_POLICY_REJECT";
}
}

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@ -0,0 +1 @@
filters = "dkim";

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@ -42,6 +42,16 @@ def test_reject_forged_from(cmsetup, maildata, gencreds, lp, forgeaddr):
assert "500" in str(e.value)
@pytest.mark.parametrize("from_addr", ["fake@example.org", "fake@testrun.org"])
def test_reject_missing_dkim(cmsetup, maildata, from_addr):
"""Test that emails with missing or wrong DMARC, DKIM, and SPF entries are rejected."""
recipient = cmsetup.gen_users(1)[0]
msg = maildata("plain.eml", from_addr=from_addr, to_addr=recipient.addr).as_string()
with smtplib.SMTP(cmsetup.maildomain, 25) as s:
with pytest.raises(smtplib.SMTPDataError, match="Spam message rejected"):
s.sendmail(from_addr=from_addr, to_addrs=recipient.addr, msg=msg)
@pytest.mark.slow
def test_exceed_rate_limit(cmsetup, gencreds, maildata, chatmail_config):
"""Test that the per-account send-mail limit is exceeded."""