#!/bin/sh
# mx      : Postfix -> pipe -> mas-gateway -> capture (JSONL evidence) -> ticket service
# statute : static /.well-known/mas only (the only thing exposed over HTTPS)
set -e
DOMAIN="${MAS_DOMAIN:-mas.coulomb.social}"
STATUTE_DIR="/app/examples/statute/$DOMAIN"

if [ "$1" = "statute" ]; then
  exec python3 /app/examples/statute/serve.py "$STATUTE_DIR" --host 0.0.0.0 --port 8080
fi

cat > /usr/local/bin/mas-gateway <<SH
#!/bin/sh
exec env PYTHONPATH=/app python3 -m mas_gateway.main "\$@"
SH
chmod +x /usr/local/bin/mas-gateway

# Not an open relay: no relay_domains, mynetworks is loopback only, so the
# only accepted recipients are @$DOMAIN, all delivered to the mas pipe.
# Stock reject_unauth_destination refuses any local-part containing '!' or '%'
# (treated as sender-specified routing), which kills every P2 address, and an
# access-map result is ignored for such routed addresses unless
# allow_untrusted_routing=yes (safe here: relay_domains is empty). So relay control is an
# explicit regexp whose match runs the `permit` restriction (not OK) for
# anything ending in @$DOMAIN; everything else falls through to `reject`
# (Postfix refuses to start smtpd without a reject-class entry in the list).
# With swap_bangpath/percent_hack off and local_transport=mas, those
# addresses can only reach the mas pipe.
DOMAIN_RE=$(printf '%s' "$DOMAIN" | sed 's/\./\\./g')
printf '/@%s$/ permit\n' "$DOMAIN_RE" > /etc/postfix/mas_rcpt.regexp
postconf -e \
  "maillog_file=/dev/stdout" "myhostname=$DOMAIN" "mydomain=$DOMAIN" \
  "mydestination=$DOMAIN" "relay_domains=" "mynetworks=127.0.0.0/8" \
  "smtpd_relay_restrictions=permit_mynetworks,check_recipient_access regexp:/etc/postfix/mas_rcpt.regexp,reject" \
  "local_transport=mas" "local_recipient_maps=" "mas_destination_recipient_limit=1" \
  "recipient_delimiter=+" "swap_bangpath=no" "allow_percent_hack=no" \
  "allow_untrusted_routing=yes" \
  "disable_vrfy_command=yes" "smtpd_helo_required=yes" "smtpd_recipient_limit=20" \
  "message_size_limit=10240000" "smtpd_banner=\$myhostname ESMTP MAS live test" \
  "smtpd_tls_security_level=may" \
  "smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem" \
  "smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key" \
  "inet_protocols=ipv4" "compatibility_level=3.6"
# start-fg does not populate the chroot (no resolv.conf), so DNS fails inside
# it: client rDNS shows "unknown" and a relayhost would not resolve. The
# container already isolates Postfix, so run the daemons unchrooted.
postconf -F '*/*/chroot = n'

# Outbound replies (reply test). Port 25 out is blocked on railiance01, so
# replies go through an authenticated submission relay, and only when its
# credentials are mounted. Only loopback (the ticket service) may relay.
# Without a relay all non-local mail fails fast instead of queueing.
SMTP_ARG=""
if [ -n "$MAS_RELAY" ] && [ -s /etc/mas-relay/username ]; then
  printf '%s %s:%s\n' "$MAS_RELAY" "$(cat /etc/mas-relay/username)" \
    "$(cat /etc/mas-relay/password)" > /etc/postfix/sasl_passwd
  chmod 600 /etc/postfix/sasl_passwd && postmap /etc/postfix/sasl_passwd
  postconf -e "relayhost=$MAS_RELAY" "smtp_sasl_auth_enable=yes" \
    "smtp_sasl_password_maps=hash:/etc/postfix/sasl_passwd" \
    "smtp_sasl_security_options=noanonymous" "smtp_tls_security_level=secure" \
    "smtp_tls_CApath=/etc/ssl/certs"
  # Postfix's own bounces (null sender) never use the relay, so the ticket
  # service cap below really bounds everything sent through TEM.
  postconf -e "sender_dependent_default_transport_maps=inline:{<>=discard:}" \
    "empty_address_default_transport_maps_lookup_key=<>"
  SMTP_ARG="--smtp 127.0.0.1:25 --max-sent ${MAS_MAX_SENT:-300} --require-dmarc-pass"
else
  postconf -e "default_transport=error:5.7.1 outbound mail disabled"
fi

# Sender authentication (spec 14 item 10). The MTA does SPF/DKIM/DMARC, since
# they need DNS; the gateway only reads Authentication-Results carrying our
# authserv-id. Postfix header_checks drop incoming A-R headers claiming that
# id; header_checks do not see milter-added headers, so only the milters'
# own results survive and a sender cannot forge a pass. (OpenDKIM's
# RemoveARFrom did not remove them in testing.) Annotate only: never reject,
# and accept mail if a milter is down. Loopback (the ticket service's
# replies) is skipped. Both milters run in the foreground: daemonized,
# OpenDKIM died on its first connection in this container.
mkdir -p /run/opendkim /run/opendmarc
chown opendkim:opendkim /run/opendkim && chown opendmarc:opendmarc /run/opendmarc
printf '127.0.0.1\n' > /etc/opendkim-peers
cat > /etc/opendkim.conf <<CONF
Mode                    v
Socket                  inet:8891@127.0.0.1
AuthservID              $DOMAIN
PeerList                /etc/opendkim-peers
UserID                  opendkim
PidFile                 /run/opendkim/opendkim.pid
Syslog                  no
CONF
cat > /etc/opendmarc.conf <<CONF
Socket                  inet:8893@127.0.0.1
AuthservID              $DOMAIN
TrustedAuthservIDs      $DOMAIN
SPFSelfValidate         true
SPFIgnoreResults        true
RejectFailures          false
PublicSuffixList        /usr/share/publicsuffix/public_suffix_list.dat
UserID                  opendmarc
PidFile                 /run/opendmarc/opendmarc.pid
Syslog                  false
CONF
opendkim -f -x /etc/opendkim.conf &
opendmarc -f -c /etc/opendmarc.conf &
printf '/^Authentication-Results:[[:space:]]*%s([[:space:];]|$)/ IGNORE\n' "$DOMAIN_RE" \
  > /etc/postfix/ar_strip.regexp
postconf -e "header_checks=regexp:/etc/postfix/ar_strip.regexp" "smtpd_milters=inet:127.0.0.1:8891,inet:127.0.0.1:8893" "non_smtpd_milters=" \
  "milter_default_action=accept" "milter_protocol=6"

cat >> /etc/postfix/master.cf <<CF
mas       unix  -       n       n       -       -       pipe
  flags=Rq user=mas argv=/usr/local/bin/mas-gateway
  --statute $STATUTE_DIR/.well-known/mas --trusted-authserv-id $DOMAIN
  pipe --app-url http://127.0.0.1:8024/mas-events --recipient \${recipient}
CF

mkdir -p /var/lib/mas && chown mas /var/lib/mas
# Replies are only recorded in the outbox unless a relay is configured above.
su -s /bin/sh mas -c "python3 /app/examples/ticket_service/ticket_service.py \
  --db /var/lib/mas/tickets.sqlite3 --listen 127.0.0.1:8025 $SMTP_ARG" &
su -s /bin/sh mas -c "python3 /app/capture.py http://127.0.0.1:8025/mas-events \
  /var/lib/mas/events.jsonl 127.0.0.1" &
exec postfix start-fg