mixandClaude Opus 5.5
14de9a05c8
internal/milter/sign.go: a milter on two sockets (cmd/panel/signer.go): sign.sock for 465/587, the key of the domain the SASL login belongs to (Bindings.DomainOf, the sender_login_maps Postfix reads), and sign-local.sock for the panel's own sendmail(1) mail, the server's name. go-msgauth/dkim v0.7.0, relaxed/simple, OpenDKIM's dkim_should_signhdrs[] (libopendkim/dkim.c:223-246) in message order plus From once more; keys and selectors from the KeyTable the panel writes, a key path outside the key directory refused; strict - whatever cannot be signed is deferred. From the sources: Postfix 3.10.13 milter8.c:2329-2400 hands a folded header \n-separated, so the signer joins its lines with CRLF; inserts are 1-based in cleanup_ins_header() (cleanup_milter.c:1193), so index 0 is the top, where OpenDKIM puts its own (opendkim.c:3673). go-milter v0.4.1 calls no Abort when a connection ends, so a watchdog closes go-msgauth's streaming signer after an hour and a late end of message is deferred. Postfix: smtpd_milters = sender check, signer, OpenDKIM, journal; non_smtpd_milters = the signer's local socket, OpenDKIM - both sign every message until stage 2. disable_mime_output_conversion=yes (default off, mail_params.h:3088): an 8-bit message is no longer re-encoded after it is signed. Tests: unit tests sign and verify folded, tab-led and space-free headers, an added From:, a changed body, two messages on a connection, odd bodies, and five cases deferred. e2e: the sink image has python3-dkim (dkimpy 1.1.8-2) and the stand's DNS; on an application's message and on a notification the two signatures must agree on h=, bh=, c=, s=, a= and each must pass dkimverify. On the server: make e2e exit 0 (714 s), go vet + go test 27 packages ok. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
33 lines
1.7 KiB
Docker
33 lines
1.7 KiB
Docker
# SMTP sink-MX for the e2e stand (plan C.4): accepts any mail on 25 and dumps
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# each transaction to its own file under /mail, so the test harness can read
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# the raw received message (headers + body, including the DKIM-Signature
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# Postfix/OpenDKIM added) straight off disk. smtp-sink ships in the postfix
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# package itself. python3-dkim (dkimpy 1.1.8-2 in trixie, /usr/bin/dkimverify)
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# is the independent DKIM verifier the suite holds the panel's signer to
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# (docs/plans/panel-dkim-signing.md); it looks the keys up through the
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# stand's CoreDNS (compose.override.yml, sink's dns).
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FROM debian:trixie-slim
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ENV DEBIAN_FRONTEND=noninteractive
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RUN echo "postfix postfix/mailname string localhost" | debconf-set-selections \
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&& echo "postfix postfix/main_mailer_type string Internet Site" | debconf-set-selections \
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&& apt-get update \
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&& apt-get install -y --no-install-recommends postfix python3-dkim \
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&& rm -rf /var/lib/apt/lists/*
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RUN mkdir -p /mail
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WORKDIR /mail
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# -d: one file per transaction (a pseudo-random suffix is appended
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# automatically), so the harness just watches the directory for a new file
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# instead of parsing a shared multi-message dump. Binding :25 needs root, and
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# smtp-sink refuses to run as root without an explicit -u to switch to after
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# binding — "-u root" satisfies that check while staying root throughout,
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# which is fine here: throwaway container, isolated e2e network, never
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# exposed. (Postfix 3.10.13, src/smtpstone/smtp-sink.c: -d "Dump each mail
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# transaction to a single-message file" named by the template plus "a
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# pseudo-random hexadecimal number"; main(): "-u option is required if running
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# as root".)
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ENTRYPOINT ["/usr/sbin/smtp-sink"]
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CMD ["-u", "root", "-d", "/mail/%Y%m%d%H%M%S.", "0.0.0.0:25", "100"]
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