Commit Graph
2 Commits
Author SHA1 Message Date
mixandClaude Opus 5.5 4433688500 findings of the security review of stage 1
The review of d254a99..fd29468 (read-only, a separate agent) found all
five fixes sound and nothing above low. Fixed here:

- The M1 e2e step passed on the unfixed code: the stranger's RSET between
  MAIL FROMs ends the transaction, Postfix's mail_reset() calls
  milter_abort(), and the old code released the slot too. The stranger now
  keeps one MAIL FROM open (strangerHoldsMailFrom) while the domain's own
  application sends; under the old code that slot was the domain's one.
- A domain import could still store a report address on the server's own
  name (W1's form rule only): checkDomainImport refuses one that is not
  the domain's own hosted address. Not a mailbox either way, but the
  panel would show an address the server refuses. Cases in
  TestDomainImportIsCheckedLikeTheForms.
- DeleteDomain matches the reports' domain without regard to case.
- A cut that fails after the journal rows were written says the rows were
  written.
- dmarc.Service.Resync and inbound.Service.Resync are serialised like
  app.Service.Resync (W3's shape, outside its diff).

Left as the review's nit: three ApplicationByLogin lookups for a refused
MAIL FROM (a refusal is rare; the store is local).

go test ./internal/dmarc ./internal/inbound ./internal/store; the import
test; GOOS=linux go vet ./test/e2e.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-17 22:13:36 +03:00
mixandClaude Opus 5.5 d254a9952d milter: the level-2 domain limit is the login's domain's (audit M1)
Security audit 2026-10-17, finding M1, stage 1. overLimit took
domainOf(MAIL FROM) whatever the login, and MailFrom ran it with an empty
login: with smtpd_delay_reject at its default Postfix runs no sender
restriction at MAIL and sends the milter's MAIL event at once, so a
stranger on 465/587 with no AUTH, or another tenant's application, could
name a victim domain in MAIL FROM and take its slots for the 10-minute
in-flight TTL, get the victim's application answered 451, and have a limit
row (and the "a rate limit is refusing mail" notification) written under
the victim's domain.

Now overLimit returns at once without a login and takes the domain from
ApplicationByLogin (loginDomain, fail-open like the rest); recordRejected's
Domain is the login's too. The send log already counts a domain's messages
by the login's domain (store.CountMessages, loginDomainID), so the limit
and the count now agree. The null-sender special case is gone: every
message is held to its login's domain.

Tests: TestRateLimitIsNotReservedByAnotherSendersMailFrom (a stranger with
no login; another tenant's application) - fails on the old code at the
second MAIL FROM; the domain-limit tests sign in as app1 at example.com.
e2e domain_limit_not_reserved_by_a_stranger: a domain with a limit of one,
three unauthenticated MAIL FROM naming it on 465, then its own message
passes and its second is refused 451.

Docs: security.md § Mail path; CHANGELOG; plan.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-17 21:41:06 +03:00