7 Commits
Author SHA1 Message Date
mixandClaude Opus 5.5 86665f08e6 audit: decisions of 2026-10-13/14 on what 2.4.0 left undone
test / test (push) Canceled after 0s
Agreed with the owner, one question at a time; documents only, no code.

From from-header-binding's Not done list, each a step of the audit plan:
the Sender check column says "Connections turned away"; a stand test of
which key OpenDKIM signs with; Health connects to a milter socket instead
of stat-ing it; the cards layout orders a phone by the box's number;
a refusal the panel did not write is recovered from mail.log; a log
rotated while the panel was down is read to its end; the deferred counter
keeps a place in the log; downtime is counted when supervisord is silent.
"Today, UTC" became the roadmap item local-time (agreed): one instance
zone, no labels beside a time, days counted in that zone, with the
conditions for per-user zones and offsets, and the trap of mail.log's own
stamps written down.

The six steps on the log tailer are split off stage 1 into stage 2b, a
cut of its own (2.5.1); stages 3 and 4 move to 2.5.2 and 2.5.3.

Also: negative e2e cases pass only on their own refusal (stage 0);
notifications are owed per recipient (stage 4); a DNS outage is unknown,
not wrong (M14, M15 had no step); DMARC reports tested where they come in.
review-2026-08-followups is closed, its rows placed in stages or dropped
with a reason. Certificate warnings by lifetime: left as is, with the
condition for return.

The audit's checklist is 61 lines (was 48).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-14 07:29:13 +03:00
mixandClaude Opus 5.5 c3d99b1f15 roadmap: decisions of 2026-10-13 on the candidates
test / test (push) Canceled after 0s
Agreed with the owner, one question at a time; documents only, no code.

- csrf-tokens -> origin-strict (agreed): no tokens, the origin check
  refuses a request with neither header. security.md's ADR records the
  decision and when tokens are built after all.
- structured-logging, contributing: dropped, each with what brings it
  back (new roadmap section "Dropped, with the condition for return").
- template-data-typing: done by 2.0.0; its last map (healthChecks) is a
  step of the audit's stage 4.
- preflight -> health-setup-checks (certificate name, Postfix's greeting,
  trusted proxy as lines on Health) and test-email, both agreed. The port
  check is dropped with its reason; plans/preflight.md removed.
- password-reset: agreed; a reset link goes only to a confirmed e-mail,
  so the item builds confirmation first.
- phone-desktop-mode: agreed, after stages 1 and 2 of the audit.
- backup-reauth (agreed): the account password before a backup or a
  domain export, out of review-2026-08-followups.
- from-header-binding, Not done: the Delivery log box is required on a
  refused message's page, with the line Postfix wrote, for all three
  kinds of refusal (audit stage 1); the Outbound log gets a filter by
  status and by day (audit stage 4).

The audit's checklist is 48 lines (was 45).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-13 19:13:04 +03:00
mixandClaude Opus 5.5 8f226bd82f release: 2.4.0: an application signs only as itself
test / test (push) Canceled after 0s
from-header-binding (docs/plans/from-header-binding.md, 9/9), at the owner's
word (2026-10-12, "Да").

  - A message's From: line is held to what its envelope sender is held to:
    any address of the application's domain, or the addresses of its list,
    with or without a +extension. Anything else is refused with 550 5.7.1 -
    another registered domain, the server's own name, a domain this server
    does not sign for. Until now an application could have mail signed with
    another domain's key by writing that domain into From:.
  - The check is the panel's, first in the milter chain and strict: while
    the panel does not answer, Postfix defers mail.
  - Server > Health counts what that costs - the panel's downtime under a
    running Postfix and the submissions turned away - and is laid out anew,
    boxes numbered by importance.
  - A refused row of the Outbound log says why in its tag.
  - Migration 0006.

Upgrading: mail whose From: is not the application's own stops being
accepted - another of your domains, an address off an application's list, a
visitor's address a form puts there. The guide says what to do about each.
A stopped panel now stops submission.

Not done, written into the plan at the owner's word: the Delivery log box on
a refused message's page, the log's status filter, "messages" that are
connections, and what was reasoned about rather than run - OpenDKIM's own
parser above all.

Cut: CHANGELOG 2.4.0 written (nothing had been put under [Unreleased]
while building); image pin 2.4.0 in compose, README, guide; version table,
roadmap, plan status. security.md: a malformed packet on a milter socket,
as an accepted risk. No tag: the owner tags when he decides to, so there is
no image of this version until then.

On the test server, on c817f08: go vet ./... ok, go test ./... ok
(23 packages), make e2e ok. This commit changes documents and the pin only.

Full detail: CHANGELOG.md (2.4.0).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-12 22:00:29 +03:00
mixandClaude Opus 5.5 c817f0833c from-header-binding: what the reviews had left as found, and address extensions
test / test (push) Canceled after 0s
The owner on the three things the reviews' commit left as found: can they be
fixed? They can.

- Downtime that crossed a UTC midnight was all booked on the day of the
  restart: it is cut at the midnights between (byDay).
- A message with the null envelope sender - a bounce an application writes
  itself - left a refusal row without a domain, which no domain
  administrator would see: the row takes the domain the login is bound to.
- A log read again after an unclean stop counted its deferrals again: while
  the tailer catches up, a warning no later than the last one counted is
  passed over. The mark is kept to the fraction of a second the log gives.

And on the check being stricter than Postfix for an address with an
extension (invoices+x@ passed in the envelope, was refused in the header):
it makes Postfix's second try now, the address without its extension.
recipient_delimiter was the distribution's default; it is set in
postfix-config.sh, since the check depends on it. e2e sends one through.

Test server, this tree: go vet ok, go test 23 packages ok, make e2e ok (339 s).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-12 21:29:17 +03:00
mixandClaude Opus 5.5 89fd0a6116 from-header-binding: findings of the technical and security reviews
test / test (push) Canceled after 0s
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
mixandClaude Opus 5.5 c171fb5bc7 from-header-binding: the sender check, what it costs, its pages; guide, architecture, security
test / test (push) Canceled after 0s
A message's From: line is held against the application that sends it, under
the rule Postfix holds the envelope sender to. OpenDKIM chooses the key by
that line, so until now an application could have mail signed as another
domain of the server or as the server itself.

The check (internal/milter/sender.go)
- A role of the panel on a socket of its own (SENDER_CHECK_SOCKET), first in
  smtpd_milters and strict: default_action=tempfail. The journal milter keeps
  its socket and stays fail-open. postfix-wrapper waits for the new socket.
- It reads no database: what an application may send as comes from Postfix's
  own sender_login_maps, what the server signs for from OpenDKIM's
  SigningTable. Both are read again when they change; one that cannot be
  read defers mail.
- One From: field, one address, allowed by the envelope's lookup; then no
  other name of the SigningTable may appear anywhere in the raw line.
  Refused: 550 5.7.1 naming the line, reduced to printable ASCII.
- A refusal is a send-log row with reason "from" and the header address
  (migration 0006), written by another goroutine and not waited for. The
  journal's refusals record their reason too (limit, client), and the
  notifier takes only a limit's.

What it costs (docs/plans/from-header-binding.md, Statistics)
- The role marks itself alive every 2 s; at start the gap since the mark is
  downtime, counted from Postfix's start if later and not at all when
  supervisord says Postfix is not running.
- The log tailer counts the connections Postfix turned away: a warning that
  names the socket, then milter-reject "Service unavailable" from the same
  smtpd. Seen on the stand: the client is refused from CONNECT on and leaves
  at AUTH (454), so no MAIL line is ever written.
- sender_check_days, a row per UTC day, kept a year.

Pages
- Health: the card "Sender check", the socket's row, and the cards layout -
  boxes numbered by importance in two stacks read in rows; the left stack
  polls, the three readings of the right one are swapped in by id.
- Outbound log: a refused row says why in its tag (wrong From, wrong client,
  rate-limited); the message's page shows the From: line and what the
  application may send as.
- Help: topic "Sender check", word for word the mockup's.

Found by the stand, fixed here: the names for the second look came from the
sender bindings, and a domain with a key and no application yet was not
among them.

e2e: negative_journal_milter_fail_open is gone - it proved that mail passes
with the panel down, which is no longer so. In its place
sender_check_holds_the_from_line (another domain's From:, the hostname's, a
stranger's, an address off the list, another sender in the display name -
refused; own addresses - delivered) and panel_down_defers_mail (4xx with the
panel stopped, the container alive, mail again after, downtime and one
deferred message on Health, the card warning).

Test server, this tree before the last cosmetic edits (a fixture row, a
fact's size, docs): go vet ok, go test 23 packages ok, make e2e ok (337 s).
Locally after them: internal/web/view ok.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-12 19:35:43 +03:00
mixandClaude Opus 5.5 972516d1c4 from-header-binding: agreed, taken into work
The design questions were closed with the owner on 2026-10-12, one at a
time; the plan records what he chose and what I had proposed instead.

- The rule: From: is held to what the envelope is held to - any address of
  the application's domain, or the addresses of its list. Anything else is
  refused, a domain this server knows nothing of included (I had proposed
  to refuse only names the server signs for).
- The check is the panel's and strict: while the panel does not answer,
  Postfix defers mail. It gets a socket of its own so that the journal
  stays fail-open, and reads Postfix's own file of sender bindings.
- Server > Health counts the panel's downtime under a running Postfix and
  the mail deferred for it, to decide later whether the check needs a
  process of its own.
- A refusal is 550 5.7.1, and its reason is the row's status tag.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-12 18:46:11 +03:00