Files
selfpost/internal/postfix/dmarc.go
T
mixandClaude Opus 5.5 1c6e04b7d3
test / test (push) Canceled after 0s
base-trixie: the image on Debian trixie, Postfix 3.10.13; Received: hidden on 465/587
The runtime base is debian:trixie-slim, the build stage golang:1.26-trixie:
Postfix 3.10.13 with upstream's 2026 security fixes up to the August
batch, libmilter 8.18.1, OpenSSL 3.5. Every citation of another program in
code, scripts and documents was re-read against the trixie sources
(dev/upstream; bookworm's kept in dev/upstream-bookworm) and updated;
development.md's cited-package table holds the trixie versions.

What the re-reading changed in behaviour:
- logtail: reject lines with sasl_method/sasl_username/sasl_sender
  (smtpd_check.c:1019-1026); cleanup's "removed (canceled)" forgets a
  port-25 id (cleanup_api.c:363-364).
- internal/postfix/retry.go reads postconf's stdout only: since 3.9 a
  deprecated-parameter warning on stderr made one value too many and the
  panel fell back to the compiled-in retry policy.
- logrotate-loop.sh: logrotate 3.22 exits 1 when it ignores a config;
  the loop refuses on that output whatever the status.
- postfix-config.sh: cyrus_sasl_config_path set explicitly (bookworm's
  07_sasl_config.diff is gone); maillog_file_permissions=0640; mynetworks
  explicit; Dockerfile: SYNC_CHROOT= in /etc/default/postfix,
  opendkim-tools dropped, openssl named, systemd-standalone-sysusers so
  cron does not bring the whole of systemd.
- The selfpost group is 10998, outside the system range 100-999: in
  trixie a package took 998 and the build failed (owner's decision:
  a conflict-free id, the distribution's own ids untouched). The
  entrypoint hands /data back by name when the user or the group differs.
  Guide, backup refusal text, help (design commit 68ec8b2), e2e.
- smtpd_hide_client_session=yes on smtps and submission (owner's
  decision): Received: names no client, TLS, login or protocol; port 25
  keeps the full header. e2e checks both.
- test/upstream/opendkim-probe.sh makes keys with openssl genrsa.

Tests: on the server, make e2e exit 0 (674 s, the image built on trixie),
go vet + go test 27 packages ok. CHANGELOG [Unreleased], guide,
architecture.md, security.md, roadmap.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-15 19:31:35 +03:00

76 lines
2.3 KiB
Go

package postfix
import (
"fmt"
"path/filepath"
"sort"
"strings"
)
// DMARCMapsConfig is the allow-list material for DMARC aggregate ingest.
type DMARCMapsConfig struct {
Recipients []string
Domains []string
}
func (p *Postfix) dmarcMapPaths() (recipients, transport, relayDomains string) {
dir := filepath.Dir(p.senderLoginMapsPath)
return filepath.Join(dir, "dmarc_recipients"),
filepath.Join(dir, "dmarc_transport"),
filepath.Join(dir, "dmarc_relay_domains")
}
// RebuildDMARCMaps regenerates DMARC ingest lookup tables. Empty config clears
// the files so port-25 ingest is off even if the listener stays up for inbound
// relay.
func (p *Postfix) RebuildDMARCMaps(cfg DMARCMapsConfig) error {
recip, transport, relay, err := renderDMARCMaps(cfg)
if err != nil {
return err
}
rc, tr, rd := p.dmarcMapPaths()
if err := writeFileAtomic(rc, recip, 0o640); err != nil {
return err
}
if err := writeFileAtomic(tr, transport, 0o640); err != nil {
return err
}
if err := writeFileAtomic(rd, relay, 0o640); err != nil {
return err
}
return p.reload()
}
// Postfix 3.10.13, man/man5/access.5: "OK" accepts the address the key
// matches; man/man5/transport.5: "user@domain transport:nexthop", and "a
// non-null transport field with a null nexthop field resets the nexthop
// information to the recipient domain"; relay_domains as in renderInboundMaps.
func renderDMARCMaps(cfg DMARCMapsConfig) (recipients, transport, relayDomains []byte, err error) {
recipients = []byte{}
transport = []byte{}
relayDomains = []byte{}
if len(cfg.Recipients) == 0 {
return recipients, transport, relayDomains, nil
}
addrs := append([]string(nil), cfg.Recipients...)
sort.Strings(addrs)
var recipB, transportB strings.Builder
for _, addr := range addrs {
if err := assertMapToken(addr, "recipient"); err != nil {
return nil, nil, nil, err
}
fmt.Fprintf(&recipB, "%s OK\n", addr)
fmt.Fprintf(&transportB, "%s dmarc-ingest:\n", addr)
}
domains := append([]string(nil), cfg.Domains...)
sort.Strings(domains)
var relayB strings.Builder
for _, d := range domains {
if err := assertMapToken(d, "domain"); err != nil {
return nil, nil, nil, err
}
fmt.Fprintf(&relayB, "%s OK\n", d)
}
return []byte(recipB.String()), []byte(transportB.String()), []byte(relayB.String()), nil
}