Security audit 2026-10-17, findings W6/M9 (low), stage 4. Every
application, upstream, recipient or report-address save reloaded Postfix
through supervisord, and POST .../dns-recheck bypassed the five-minute
cache for up to ~14 resolver queries - both at whatever rate an
authenticated user pressed.
- writeChanged: each generated map is written only when its content
differs from the file on disk, and Postfix is reloaded only when one was
(sender map, inbound maps, DMARC maps). Health's Reload configuration
ends with an explicit reload (app.Service.ReloadPostfix, SenderMaps
gains Reload), so it still re-reads whatever is on disk. No debounce:
with unchanged saves gone, a burst is real changes Postfix must see.
- auth.AllowDNSRecheck: twenty forced re-checks in 15 minutes per user;
past that the outbound, inbound and settings re-check show the cached
result without the "re-checked" flash, and the log says why.
Tests: TestARebuildThatChangesNothingDoesNotReload,
TestDNSRechecksArePerUser; the fakes gain Reload. Docs: guide § Overview
and Health; CHANGELOG; plan.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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>
M14, M15: queryEach gives each resolver 2 s within the check's context and
asks the one that answered last first; an address or PTR lookup not
answered is Unknown, an answered mismatch beside it still an error;
Checker.Server keeps the last answer's addresses, so SPF does not go Unknown
with it. Notifications report faults only, now tested with SPF unknown
alone and beside a wrong DKIM.
DMARC reports: tests of malformed XML, gzip and zip bombs, a message over
the limit, the service's Resync, hosted suggestion and validation. The
finding: both limits cut silently and an oversized report failed as
damaged; readAtMost refuses it for its size (MaxMessage 10 MiB, moved into
IngestMessage).
healthReadings replaces map[string]any for Health and Overview.
L5: an inbound upstream has one TLS mode - a second domain to the same
[host]:port with another mode is refused, naming the first; the TLS policy
map holds each next hop once.
Tested on the test server: go vet + go test of 25 packages, make e2e (all
pass, 631 s) on this tree.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Comments only, no behaviour changed. go-milter v0.4.1 (session.go: one
session per connection, replaced after a non-continue reply; macros per
stage), Postfix 3.7.11 (milter8.c, smtpd_check.c
reject_auth_sender_login_mismatch(), mail_addr_find.c, showq_compat.c,
mail_conf_time.c, mail_params.h), Cyrus SASL 2.1.28 (saslpasswd.c,
plugins/sasldb.c: deleting a missing login is not an error), OpenDKIM
2.11.0~beta2 (opendkim-db.c, opendkim-genkey), Berkeley DB 5.3 db_dump,
rspamd 3.11.0. Comments that claimed what the source denies are corrected
(sasldb keeps the password as given, not hashed; an embedded newline is
kept, not truncated; rspamd sorts symbols by absolute weight); fixtures say
seen or composed. The sender check's From: parsing gets no citations: it is
replaced by the port of OpenDKIM's dkim_mail_parse next.
Contradictions left for their own commits: B-G5 cleanAddress, B-PS1 first
key wins, B-PQ1 the forced-expire flag, B-PQ10/PQ11 Postfix's time units.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Review pass over `1.4.0`…`1.9.1`: port 25 no longer shares the submission milter chain, DMARC reports are validated before they are stored, and the auto rate limit is correct for a non-default level-1 window. Schema migration `0010` (index only). Upgrading is a tag bump.
Added:
- SQLite migration `0010_send_log_app_login_index.sql` —
- DMARC aggregate reports are accepted as **zip** as well as gzip or plain XML
- e2e: `checkPort25ConfigCombinations` regenerates the Postfix configuration
Changed:
- README hero line and a **Positioning** block in `docs/product.md` record the
Fixed:
- The setup account's password is hashed at bcrypt cost `12` like every other
- Login/setup rate limiter: protecting blocked buckets from eviction is now
- `postqueue -p` output is bounded to 4 MiB (the timeout alone left the size of
- [schema-migrations.md](docs/schema-migrations.md): the schema section was
- postqueue reader is now time-bounded: `postqueue -p` runs under a 5-second
… (11 more in CHANGELOG)
Changed:
- [roadmap.md](docs/roadmap.md) now carries everything the 2026-08-19 code
- Extracted `internal/configsafe` — the empty-value and forbidden-character
- Build, deploy and migration comments no longer cite the archived
- Dropped the `parseDomainRateLimitForm` / `parseAppRateLimitForm` pass-through
- Extracted shared helpers: `internal/atomicfile` (atomic temp-write+rename) and
… (7 more in CHANGELOG)
Removed:
- Unused legacy asset `docs/assets/icon.png` (superseded by the four brand SVGs
- Plan documents for already-shipped features: `domain-stats-auto-ratelimit`,
Full detail: CHANGELOG.md (1.9.2).
Optional inbound relay (backup-MX / forwarder) on port 25, off by default. Mail is accepted only for domains configured in the panel and forwarded to an upstream; there are still no mailboxes. A dedicated security review of the inbound path is still open on the plan (Fable).
Added:
- `INBOUND_RELAY_ENABLE` (default `false`): when true, Postfix listens on
- Panel **Inbound** pages (global administrator): domains, upstream host/port
- Optional `INBOUND_ANTISPAM_MILTER` on the inbound listener only, plus
- Inbound rate limit (`INBOUND_RATE_LIMIT_MESSAGES_PER_IP`, default 20) and
Changed:
- Compose publishes host port 25 even when the flag is off (nothing listens
- Full-backup restore Resync also rebuilds inbound maps when the flag is on.
Full detail: CHANGELOG.md (1.4.0).
mixandClaude Opus 5.5