Full MEL->Serilog migration via AddZbSerilog; GatewayLogRedactor exposed through
the shared ILogRedactor seam; GatewayMetrics now exports via AddZbTelemetry + new
/metrics (meter name MxGateway.Server + ms histogram units unchanged; rename/unit
conversion deferred). Behaviour-preserving.
Best-effort resolve the host FQDN via Dns.GetHostEntry and add it as a
DNS SAN when it differs (OrdinalIgnoreCase) from the short machine name
and "localhost". SocketException / ArgumentException are caught and
silently skipped so cert generation remains robust when DNS is absent.
Wrap the WriteAllBytes/Move/HardenPermissions sequence in a try/catch so
that any failure best-effort deletes the hardened .tmp file (which may
already hold PFX/private-key bytes) before rethrowing. Add a test that
induces a persist failure by pointing SelfSignedCertPath inside a
regular file and asserts no .tmp is left on disk.
Extract the TLS-without-CA guard into a shared `build_tls_config` helper
in options.rs so both GatewayClient and GalaxyClient use identical logic.
GalaxyClient previously had no guard, so TLS-without-CA produced a cryptic
tonic handshake failure; it now returns the same actionable InvalidEndpoint
error. The guard message notes that a server-name override affects SNI but
does not pin trust. Add --require-certificate-validation to ConnectionArgs
in the CLI binary. Add a mirror test for GalaxyClient in tests/tls.rs.
Drop KeyEncipherment from the self-signed cert's key-usage extension — it
is semantically wrong for ECDSA (RSA key-transport only); DigitalSignature
alone is correct for TLS 1.3 / ECDHE server certs. CertificateRequest is
unchanged (not IDisposable in .NET 10). Test now also asserts MachineName,
127.0.0.1 and IPv6 loopback are present in the SAN extension.
Mirror MxGatewayClient's three-branch handler structure in GalaxyRepositoryClient
(CA-pin / lenient accept-all / OS trust) so the Galaxy endpoint works against the
gateway's self-signed cert under the default lenient posture. Expose an internal
CreateHttpHandlerForTests seam for unit testing. Add RemoteCertificateNameMismatch
rejection at the top of both CA-pinned callbacks so a pinned-CA connection truly
verifies the host. Strengthen existing lenient test to invoke the callback and assert
it returns true; add mirrored Galaxy-client handler tests.
Joseph Doherty