Audit H2 (Alto). The binary defaulted to --bus-auth off, the NATS nkey
authenticator only turned on under enforce, and TLS was an independent flag.
Booting --bind 0.0.0.0 --tls-cert … without --bus-auth enforce left both
planes open while looking secure.
validateBootConfig is a pure guard, called right after flag parsing, that
log.Fatals on two insecure shapes:
- a non-loopback --bind without --bus-auth enforce, and
- --tls-cert/--tls-key without --bus-auth enforce.
An insecure public startup is now impossible (the process exits), so a
fail-open data plane never comes up for an unregistered client to reach.
TestAudit_FailOpenTLSWithoutAuth plus a full policy table cover golden
(public+enforce, dev loopback) and every refused shape.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>