Phase 3 PR 31 — Live-LDAP integration test + Active Directory compatibility. Closes LMX follow-up #4 with 6 live-bind tests in Server.Tests/LdapUserAuthenticatorLiveTests.cs against the dev GLAuth instance at localhost:3893 (skipped cleanly when unreachable via Assert.Skip + a clear SkipReason — matches the GalaxyRepositoryLiveSmokeTests pattern). Coverage: valid credentials bind + surface DisplayName; wrong password fails; unknown user fails; empty credentials fail pre-flight without touching the directory; writeop user's memberOf maps through GroupToRole to WriteOperate (the exact string WriteAuthzPolicy.IsAllowed expects); admin user surfaces all four mapped roles (WriteOperate + WriteTune + WriteConfigure + AlarmAck) proving memberOf parsing doesn't stop after the first match. While wiring this up, the authenticator's hard-coded user-lookup filter 'uid=<name>' didn't match GLAuth (which keys users by cn and doesn't populate uid) — AND it doesn't match Active Directory either, which uses sAMAccountName. Added UserNameAttribute to LdapOptions (default 'uid' for RFC 2307 backcompat) so deployments override to 'cn' / 'sAMAccountName' / 'userPrincipalName' as the directory requires; authenticator filter now interpolates the configured attribute. The default stays 'uid' so existing test fixtures and OpenLDAP installs keep working without a config change — a regression guard in LdapUserAuthenticatorAdCompatTests.LdapOptions_default_UserNameAttribute_is_uid_for_rfc2307_compat pins this so a future 'helpful' default change can't silently break anyone.

Active Directory compatibility. LdapOptions xml-doc expanded with a cheat-sheet covering Server (DC FQDN), Port 389 vs 636, UseTls=true under AD LDAP-signing enforcement, dedicated read-only service account DN, sAMAccountName vs userPrincipalName vs cn trade-offs, memberOf DN shape (CN=Group,OU=...,DC=... with the CN= RDN stripped to become the GroupToRole key), and the explicit 'nested groups NOT expanded' call-out (LDAP_MATCHING_RULE_IN_CHAIN / tokenGroups is a future authenticator enhancement, not a config change). docs/security.md §'Active Directory configuration' adds a complete appsettings.json snippet with realistic AD group names (OPCUA-Operators → WriteOperate, OPCUA-Engineers → WriteConfigure, OPCUA-AlarmAck → AlarmAck, OPCUA-Tuners → WriteTune), LDAPS port 636, TLS on, insecure-LDAP off, and operator-facing notes on each field. LdapUserAuthenticatorAdCompatTests (5 unit guards): ExtractFirstRdnValue parses AD-style 'CN=OPCUA-Operators,OU=...,DC=...' DNs correctly (case-preserving — operators' GroupToRole keys stay readable); also handles mixed case and spaces in group names ('Domain Users'); also works against the OpenLDAP ou=<group>,ou=groups shape (GLAuth) so one extractor tolerates both memberOf formats common in the field; EscapeLdapFilter escapes the RFC 4515 injection set (\, *, (, ), \0) so a malicious login like 'admin)(cn=*' can't break out of the filter; default UserNameAttribute regression guard.
Test posture — Server.Tests Unit: 43 pass / 0 fail (38 prior + 5 new AD-compat guards). Server.Tests LiveLdap category: 6 pass / 0 fail against running GLAuth (would skip cleanly without). Server build clean, 0 errors, 0 warnings.
Deferred: the session-identity end-to-end check (drive a full OPC UA UserName session, then read a 'whoami' node to verify the role landed on RoleBasedIdentity). That needs a test-only address-space node and is scoped for a separate PR.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/v2/lmx-followups.md

@@ -58,18 +58,25 @@ Deferred: flipping `AutoAcceptUntrustedClientCertificates` to `false` as the
 deployment default. That's a production-hardening config change, not a code
 gap — the Admin UI is now ready to be the trust gate.
 
-## 4. Live-LDAP integration test
+## 4. Live-LDAP integration test — **DONE (PR 31)**
 
-**Status**: PR 19 unit-tested the auth-flow shape; the live bind path is
-exercised only by the pre-existing `Admin.Tests/LdapLiveBindTests.cs` which
-uses the same Novell library against a running GLAuth at `localhost:3893`.
+PR 31 shipped `Server.Tests/LdapUserAuthenticatorLiveTests.cs` — 6 live-bind
+tests against the dev GLAuth instance at `localhost:3893`, skipped cleanly
+when the port is unreachable. Covers: valid bind, wrong password, unknown
+user, empty credentials, single-group → WriteOperate mapping, multi-group
+admin user surfacing all mapped roles.
 
-**To do**:
-- Add `OpcUaServerIntegrationTests.Valid_username_authenticates_against_live_ldap`
-  with the same skip-when-unreachable guard.
-- Assert `session.Identity` on the server side carries the expected role
-  after bind — requires exposing a test hook or reading identity from a
-  new `IHostConnectivityProbe`-style "whoami" variable in the address space.
+Also added `UserNameAttribute` to `LdapOptions` (default `uid` for RFC 2307
+compat) so Active Directory deployments can configure `sAMAccountName` /
+`userPrincipalName` without code changes. `LdapUserAuthenticatorAdCompatTests`
+(5 unit guards) pins the AD-shape DN parsing + filter escape behaviors. See
+`docs/security.md` §"Active Directory configuration" for the AD appsettings
+snippet.
+
+Deferred: asserting `session.Identity` end-to-end on the server side (i.e.
+drive a full OPC UA session with username/password, then read an
+`IHostConnectivityProbe`-style "whoami" node to verify the role surfaced).
+That needs a test-only address-space node and is a separate PR.
 
 ## 5. Full Galaxy live-service smoke test against the merged v2 stack