Anonymous sessions used to short-circuit in HandleImpersonation — "let the SDK's
default validation stand" — so they always connected and always carried no roles.
Now admission and authority are separated:
admission -> OpcUa:AllowAnonymous, the HOST's decision (it owns token policies)
authority -> the authenticator, resolving the reserved principal "anonymous"
through the SAME grant path a key's principal goes through
So anonymous can be granted WRITE, not merely tolerated as read-only, and it
arrives at the downstream gates as the same RoleCarryingUserIdentity a key
produces — which is the real payoff: no gate carries an anonymous-shaped branch,
so there is no bypass path to get wrong.
AllowAnonymous defaults to TRUE on purpose. Defaulting it false would silently
deny every client without a key the moment this deploys, including ScadaBridge's
Data Connection Layer in another repo. Making keys mandatory is a rollout
decision, not an upgrade side effect. When false, the Anonymous token policy is
withheld so a client is refused at DISCOVERY rather than only at activation, and
activation is rejected independently in case a client attempts a token type the
endpoint never advertised.
Two fail-closed choices, both falsified:
- A failure to read anonymous's grants DENIES rather than admitting with no
roles. Admitting is the pre-#520 behaviour, and defaulting to it exactly when
the server cannot determine what anonymous may do stops being harmless once
reads are gated. Making it admit reds Anonymous_denies_when_grants_cannot_be_read.
- A key may not authenticate as the reserved "anonymous" principal, or a
credentialled client silently inherits whatever anonymous was granted.
AuthenticateAnonymousAsync is a DEFAULT interface implementation returning
admit-with-no-roles, i.e. exactly the pre-#520 behaviour, so
NullOpcUaUserAuthenticator and every test double keep working rather than being
forced to reimplement it — important because driver-only nodes run the Null one
and would otherwise black out. Note a default interface method is only reachable
through the interface-typed reference, which is how OpcUaApplicationHost holds it.
An existing test asserted the old fall-through and correctly went red; it is
rewritten to pin the new contract rather than deleted, with the reason recorded.
OpcUaServer 366, Host 42 green.
Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
Stop discarding the authenticator's resolved roles during impersonation.
HandleImpersonation now sets args.Identity to a RoleCarryingUserIdentity
(: UserIdentity) that carries result.Roles, so a downstream method handler
can read them off context.UserIdentity for the inbound AlarmAck gate (T18).
Verified via the decompiled SDK (1.5.378.106) that the instance we assign to
ImpersonateEventArgs.Identity is stored by reference onto Session.Identity /
EffectiveIdentity and surfaced unchanged on OperationContext.UserIdentity --
the custom subclass survives the round-trip. No auth-decision logic changes.
Opc.Ua.Server was pinned 1.5.374.126 while Client/Configuration were 1.5.378.106, so the
published Host unified Opc.Ua.Core to 1.5.378 (which dropped Opc.Ua.INodeIdFactory that Server
1.5.374 referenced). Every driver-role node (and the fused site nodes) failed to start the OPC
UA server with TypeLoadException, leaving the OPC data plane dead and the site UIs at 503.
Align all OPC UA packages to 1.5.378.106 (bump Server; drop the Opc.Ua.Configuration/Client
VersionOverrides in OpcUaServer + its integration tests) and port the server host to the
1.5.378 async API:
- ApplicationInstance requires an ITelemetryContext ctor (DefaultTelemetry.Create)
- Start/Stop/LoadApplicationConfiguration/Validate -> async; CheckApplicationInstanceCertificate
-> CheckApplicationInstanceCertificatesAsync
- ImpersonateEventHandler is now (ISession, ImpersonateEventArgs)
- UserNameIdentityToken.DecryptedPassword is now byte[] (UTF-8 decode)
- tests ported (byte[] passwords; async discovery/session/read client API)
Verified: full solution builds, OpcUaServer unit tests 52/52, and in docker-dev all six OPC
endpoints (4840-4845) listen and the site UIs return 302 (were 503). End-to-end OPC behaviour
(read/write/subscribe/security under 1.5.378) still needs a functional client test.
Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.
Adds IOpcUaUserAuthenticator seam in OpcUaServer.Security with a deny-all
NullOpcUaUserAuthenticator default. OpcUaApplicationHost subscribes to
SessionManager.ImpersonateUser after _application.Start so UserName tokens
flow through the authenticator and either attach a UserIdentity to the
session (Allow) or set IdentityValidationError = BadIdentityTokenRejected
(Deny / authenticator exception). Anonymous + X509 tokens fall through to
SDK defaults.
LdapOpcUaUserAuthenticator (Host project) bridges to the same
ILdapAuthService that AddOtOpcUaAuth uses for Admin cookies / JWT, so a
single LDAP source-of-truth governs both Admin control plane and OPC UA
data plane. Program.cs registers LdapOptions + LdapAuthService +
IOpcUaUserAuthenticator on driver-role hosts; admin-only nodes are
unchanged.
OtOpcUaServerHostedService threads the resolved authenticator into
OpcUaApplicationHost so the seam respects Host DI.
10 new tests: 6 in OpcUaServer.Tests cover the pure HandleImpersonation
static method (success / denial / anonymous fallthrough / authenticator-
throw / null-username / Null authenticator); 4 in Host.IntegrationTests
cover the LdapOpcUaUserAuthenticator adapter (LDAP allow → Allow with
roles, LDAP deny → Deny, exception → backend-error denial, display-name
fallback). OpcUaServer suite is 40 / 40 green.
Closes#104. Unblocks Task 60 (dual-endpoint + ServiceLevel tests) once
#81 residual lands.
Joseph Doherty