Commit Graph
5 Commits
Author SHA1 Message Date
mixandClaude Opus 5.5 e166a2ebd6 refused messages: the page shows what Postfix wrote (stage 2b, 0009)
The Delivery log box of every refused row said "This message never reached
the queue, so Postfix wrote no delivery lines for it" - untrue: Postfix
wrote a line for each. The owner, 2026-10-13: the box is required on every
message page. Pictured for him first (dev/shots, the refused variant of
out-message: wrong From with its queue id lines, rate-limited with the
NOQUEUE line); the variant has no mockup screen of its own - the guard ties
screens to pages, and its outline is out-message's.

- Wrong From: cleanup gives the message a queue id before the headers are
  judged; the sender check reads {i} at end-of-headers and writes it on the
  refused row. Its lines - stored under the id like any other's - are on the
  page, but only those from 10 minutes before to 1 minute after the refusal
  (store.SendLogLines for a rejected row): Postfix frees the id at once, and
  a later message with it lends nothing. No mail.log fallback for a refused
  row, for the same reason.
- Rate-limited and wrong client: refused at MAIL FROM, no queue id. Migration
  0009 adds send_log.refusal_line; logtail.refusalLines matches smtpd's
  "NOQUEUE: milter-reject: MAIL from ...; from=<...>" (not port 25's, not
  CONNECT/EHLO) and store.AttachRefusalLine puts it on the newest refused row
  of that sender (and login, when the line names it) within two minutes; a
  line whose row is not written yet waits up to 30 s (retried at each pass).
- The page: the queue id fact says "given, the message was not queued" or
  "none - refused at MAIL FROM, before one is given"; the box's caption is
  "The line from mail.log for this refusal" for the latter; a row from
  before says the line was not kept. LogLineLevel colours a refusal by its
  reply: 5xx red, 4xx amber (IPv6 clients included). The id in the fact is
  not muted as in the picture: the kit has no muted inline.

Tests: store (attach by sender, login, time; not a queued row, not one an
hour off; a refused row's lines are its own minutes); logtail (attach, wait
and retry, port 25 and other lines ignored); milter (the refused row carries
{i}); view (facts, caption, line levels); handlers (the line on the page,
the sentence without it). e2e refusals_show_postfixs_line: a client-address
refusal made there, and the pages of a wrong From, a rate-limited and a
wrong client refusal each show Postfix's line.

schema-migrations row 9, CHANGELOG [Unreleased], audit plan line ticked,
roadmap 25/62.
Evidence on the test server for this tree: make e2e exit 0 (the new case
in 5.4 s); go test ./... ok but for two schema tests, fixed after the run
(the schema at 0009) - store tests ok locally; the full run follows before
the push.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-14 16:56:29 +03:00
mixandClaude Opus 5.5 5747f0b25c sender check: the reply names no other domain (L8); which key signs, tested (stage 2)
L8: a From: line naming another sender of the server was refused with
"it names another sender of this server, <domain>" - a confirmation, to
whoever tries names, that the domain is hosted here. The reason now stops
before the domain; the line as written stays in the reply (the client's own
text) and on the refused message's page (header_from). Unit test: the reason
of every refusal names none of the server's other domains; e2e: the reason
of each sender-check refusal does not contain other.e2e.test.

Which key OpenDKIM signs with (owner, 2026-10-13): the check and OpenDKIM
read From: with two parsers, and their agreement was argued, never run.
internal/milter/testdata/from-lines-passed.txt holds the lines the check
passes for an application - bare and bracketed, quoted names with a comma,
escaped quotes and an address inside, an extension, three encoded charsets,
two folded lines, comments (nested too), a stranger's address in the name -
as Go-quoted strings with {domain}. The unit test wants each passed; the new
e2e case passed_from_lines_signed_for_their_domain_only sends each as app1
and wants every DKIM signature at the sink to be for the sender domain,
with one valid. All fifteen were. "(the shop) a@domain" - a comment before
the address, valid RFC 5322 - is refused by the check ("it must be one
address"); strict, not a hole, so it is not in the file. Groups are refused
too.

Audit plan lines ticked (two) with what was found, CHANGELOG [Unreleased],
roadmap 21/62.
Evidence on the test server for this tree (with a618ffb): go vet clean, go
test ./... 23 packages ok, make e2e exit 0 - the new case passed in 4 s.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-14 15:44:57 +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