Files
selfpost/build/entrypoint.sh
T
mixandClaude Opus 5.5 89fd0a6116
test / test (push) Canceled after 0s
from-header-binding: findings of the technical and security reviews
Both reviews were of c171fb5, read-only, given the code and questions.

Found by both, and the one that would have refused ordinary mail from the
first day: a folded From: line - what a mail library makes of a long display
name - did not parse and was refused with 550. The line is unfolded before it
is read. e2e sends one through Postfix now.

Technical (Opus)
- A display name in a charset Go does not convert (windows-1251, koi8-r) was
  refused: such a name is passed through unread, only the address is judged.
- The statistics ran between binding the socket and serving it, with a
  supervisorctl that has no timeout: they are kept beside the check now and
  nothing of them is waited for. A supervisorctl that fails is logged.
- The count of deferred mail followed smtpd's reject lines and so missed a
  check that stops answering in the middle of a message, where cleanup
  writes them: it is taken at Postfix's warning, the line that names the
  socket. The test line for that case had been invented with the wrong
  process; it is marked as composed from Postfix's source.
- A card whose figures could not be read showed zeros and "ok": dashes and
  "unknown".
- entrypoint removes the sockets a killed container left, which satisfied
  the wrapper's wait before the check was listening.
- Outside quoted strings the line may hold one "@" only - a rule that needs
  no knowledge of OpenDKIM's parser.
- Comments that still spoke of two sockets, or of a session replaced after a
  refusal; the limits of the cards layout on a phone, said where it is defined.

Security (Fable; no Critical or High)
- Another sender's name in an encoded display name passed the second look:
  the decoded name is looked at as well.
- A client could arm the deferred counter by sending the socket's name where
  Postfix quotes it in a warning: the two warnings are matched from their
  first word.
- A refused message wrote a row per recipient: one row, naming the first
  recipient and how many more.
- Docs: the check's lookup is stricter than Postfix's for address extensions
  and the case of logins, rather than "cannot disagree"; what a display name
  looks like to a person is not promised; the timeouts and the 454 at AUTH
  stated as they are; "messages" are connections turned away.

Left as found, in the plan: downtime that crosses midnight is booked on the
day of the restart; a message with the null envelope sender leaves a row
without a domain; a log read again after an unclean stop counts again.

Test server, this tree: go vet ok, go test 23 packages ok, make e2e ok (330 s).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-12 20:06:02 +03:00

187 lines
9.2 KiB
Bash

#!/bin/sh
# Container entrypoint (runs as root, PID 1 until it execs supervisord).
#
# SELFPOST_HOSTNAME is checked first (plan B.3): it must fail fast with a clear
# message before /data normalisation or Postfix config, so a bad identity never
# looks like a permissions or packaging problem (and so the e2e hostname-gate
# tests see the FATAL text rather than an earlier set -e abort).
set -e
# SELFPOST_HOSTNAME is an identity, not a setting with a safe default: it must
# simultaneously match the PTR/rDNS record, the certificate CN/SAN, and the
# Cyrus SASL realm. The panel (main.go saslRealm()) and postfix-config.sh each
# fall back independently when it's unset — to `localhost` and to the container
# hostname respectively — so accounts get written under one realm and looked up
# under another and authentication silently fails for every application, while
# HELO also stops matching the PTR record and mail that does go out lands in
# spam. No fallback can be correct, so fail loudly here, before either side of
# that split has a chance to run, rather than leave a green panel with broken
# mail.
if [ -z "$SELFPOST_HOSTNAME" ]; then
cat >&2 <<'EOF'
FATAL: SELFPOST_HOSTNAME is not set.
This is the mail server's identity: it becomes the Postfix HELO/EHLO name,
the Cyrus SASL realm that application passwords are looked up under, and it
must match the TLS certificate's CN/SAN as well as this server's PTR (reverse
DNS) record. There is no safe default — guessing any one of these wrong
breaks authentication for every application or sends outgoing mail to spam,
silently.
Set it to the mail server's fully-qualified domain name, e.g.:
SELFPOST_HOSTNAME=mail.example.com
in the .env file next to your docker-compose.yml (see deploy/.env.example).
EOF
exit 1
fi
case "$SELFPOST_HOSTNAME" in
*[\ \ ]* | *://* | *:* )
echo "FATAL: SELFPOST_HOSTNAME must be a bare hostname (no scheme, port, or spaces): \"$SELFPOST_HOSTNAME\"" >&2
echo 'Example: SELFPOST_HOSTNAME=mail.example.com' >&2
exit 1
;;
*.*)
;;
*)
echo "FATAL: SELFPOST_HOSTNAME must be a fully-qualified domain name (at least one dot): \"$SELFPOST_HOSTNAME\"" >&2
echo 'Example: SELFPOST_HOSTNAME=mail.example.com' >&2
exit 1
;;
esac
# The persistent root /data is a host bind mount, so it arrives owned by the
# host user (typically root), not by the unprivileged panel user that actually
# writes the SQLite database, setup token and DKIM keys. Fix its ownership here
# — the one place still running as root — before handing off to supervisord,
# which starts the panel as the panel user.
#
# Mode must stay world-traversable (0755): OpenDKIM and Postfix reach their
# trees under /data as other users. Go's testing.TempDir is 0700, and a bare
# chown would leave that mode in place — opendkim then cannot read KeyTable and
# the container crash-loops (e2e TestHostnameGate/valid_hostname_starts).
chown panel:panel /data
chmod 755 /data
# Restored backups or previously-created state may contain panel-owned files
# under /data; make sure they stay writable without disturbing anything that a
# later phase deliberately hands to another service. /data/log is exempt: it is
# deliberately owned by postfix (postlogd writes the delivery log there) and is
# normalised on its own below.
find /data -mindepth 1 -maxdepth 1 ! -user panel ! -name log ! -name postfix -exec chown -R panel:panel {} +
# DKIM key tree. The panel (user `panel`) generates keys and writes
# the OpenDKIM tables; OpenDKIM (user `opendkim`) must read them. Normalise the
# tree on every start so it is correct whether /data is fresh, restarted, or
# just restored from a backup:
# - group `selfpost` + setgid on directories so anything the panel creates
# inherits the shared group OpenDKIM traverses;
# - private keys and tables group-readable (0640);
# - both table files present (empty is fine) BEFORE OpenDKIM starts, so the
# daemon comes up cleanly with no domains yet.
mkdir -p /data/opendkim/keys
for t in /data/opendkim/KeyTable /data/opendkim/SigningTable; do
[ -e "$t" ] || : > "$t"
done
chown -R panel:selfpost /data/opendkim
find /data/opendkim -type d -exec chmod 2750 {} +
chmod 0640 /data/opendkim/KeyTable /data/opendkim/SigningTable
find /data/opendkim/keys -type f -name '*.private' -exec chmod 0640 {} +
# Application SASL accounts. The panel (user `panel`) writes the
# sasldb2 via saslpasswd2; Postfix (user `postfix`) reads it to authenticate SMTP
# clients. Share it through the `selfpost` group the same way as the DKIM tree:
# setgid directory so new files inherit the group, and the database itself
# group-readable (0640).
mkdir -p /data/sasl
chown -R panel:selfpost /data/sasl
chmod 2750 /data/sasl
[ -e /data/sasl/sasldb2 ] && chmod 0640 /data/sasl/sasldb2
# Postfix state under /data (architecture.md § Persistence). The panel writes
# sender_login_maps; Postfix owns the on-disk queue tree under queue/.
mkdir -p /data/postfix/queue
[ -e /data/postfix/sender_login_maps ] || : > /data/postfix/sender_login_maps
# Inbound relay maps (written by the panel when INBOUND_RELAY_ENABLE=true).
# Empty files keep postfix check happy if the flag is on before any domain exists.
for f in relay_domains transport relay_recipients tls_policy; do
[ -e "/data/postfix/$f" ] || : > "/data/postfix/$f"
chown panel:selfpost "/data/postfix/$f"
chmod 0640 "/data/postfix/$f"
done
chown panel:selfpost /data/postfix
chmod 2750 /data/postfix
# Filter lists for the external spam filter (written by the panel when
# INBOUND_RELAY_ENABLE=true, read by the antispam sidecar, which mounts this
# directory). The sidecar runs under a user of its own in another container,
# so the directory and its files are readable by anyone: they hold sender
# addresses and networks, no secrets.
mkdir -p /data/antispam
chown panel:selfpost /data/antispam
chmod 0755 /data/antispam
chown panel:selfpost /data/postfix/sender_login_maps
chmod 0640 /data/postfix/sender_login_maps
# Delivery log (architecture.md § Log tailer). postlogd writes it as user
# `postfix`; the panel reads it for the log-tailer and the System log page. It
# lives under /data — not the ephemeral /var/log — so the delivery lines that
# resolve a "queued" send-log row survive a container recreate.
#
# postlogd creates a missing log itself, but at 0600, which the unprivileged
# panel cannot read; so create it here (and re-normalise an existing one, plus
# whatever logrotate left behind) at 0640 owned postfix:selfpost. The setgid
# directory keeps the shared group on anything created inside it later, and
# 2750 keeps it group-traversable but not group-writable — logrotate refuses to
# rotate a log whose directory is writable by a non-root group.
mkdir -p /data/log
[ -e /data/log/mail.log ] || : > /data/log/mail.log
chown -R postfix:selfpost /data/log
chmod 2750 /data/log
find /data/log -type f -exec chmod 0640 {} +
# Milter socket directories. Postfix (user `postfix`) must actually CONNECT to
# the milter sockets — OpenDKIM's and the panel's — not just probe them at
# start-up. The sockets are created by the opendkim and panel
# users respectively, so bridge them to `postfix` through the shared `selfpost`
# group: group-owned + setgid dirs mean each socket created inside inherits
# group `selfpost`, and group-traversable (2750) lets postfix reach it. Without
# this, smtpd cannot talk to OpenDKIM and, because signing is strict
# (default_action=tempfail), rejects all mail.
mkdir -p /run/opendkim /run/selfpost
chown opendkim:selfpost /run/opendkim
chown panel:selfpost /run/selfpost
chmod 2750 /run/opendkim /run/selfpost
# A container that was killed leaves its sockets behind, and a file nobody
# listens on would satisfy postfix-wrapper.sh's wait: Postfix would start
# before the sender check does and defer mail until it is there. The check's
# alive mark stays - it is how the downtime of a restart is told.
rm -f /run/opendkim/*.sock /run/selfpost/*.sock
# Generate the outbound-relay Postfix configuration from the environment (spec
# 5). Kept out of the image build so cert paths, rate limits, hostname and the
# optional 587 service are all driven by env at run time, and re-derived on every
# start the same way the /data normalisation above is.
/usr/local/bin/postfix-config.sh
# Initialise the persistent queue tree on first start or after restore. postfix
# set-permissions reads queue_directory from main.cf (set by postfix-config.sh).
if [ ! -d /data/postfix/queue/active ]; then
postfix set-permissions
fi
chown -R postfix:postfix /data/postfix/queue
# The recursive chown above would leave public/ and maildrop/ in group postfix.
# Postfix keeps those two in its setgid group: postqueue and postdrop are setgid
# postdrop and reach the showq socket and the maildrop directory through that
# group alone. With the wrong group `postqueue -p` run by the panel answers
# "Connect to the Postfix showq service: Permission denied" and the panel cannot
# read the queue (the Queue card and the Outbound queue page).
chgrp postdrop /data/postfix/queue/public /data/postfix/queue/maildrop
# It would also leave the queue directory itself and pid/ owned by postfix.
# Postfix keeps those two owned by root (master, which runs as root, is the only
# writer) and logs "warning: not owned by root" for each at every start.
chown root /data/postfix/queue /data/postfix/queue/pid
exec /usr/bin/supervisord -c /etc/supervisor/supervisord.conf