Fail-Closed Access: Custom Roles and Federated Identity

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Ansina’s identity layer moved from static role assumptions to fail-closed, federated access control.

M3 shipped custom roles, TOTP step-up, credential expiry, role-mapping provenance, and an OAuth 2.0/OIDC login exchange. The common thread is structural enforcement: permissions must match served routes, sensitive mutations require live step-up, and federated claims cannot silently override local assignments.

⚡ Fail-Closed Authorization

  • Sudo gate — SudoRequiredError now applies to every non-admin role on sensitive resources. A custom role granting auth.* cannot bypass step-up by avoiding the old maintain slug.
  • Factor registry — StepUpRegistry returns every enrolled verifier, while GET /auth/me exposes step_up_factors. Zero factors, unknown factors, and ambiguous requests fail with 403 without consuming lockout attempts.
  • Grant fidelity — Resource catalogs now persist served verbs and policy class. Builtin grants are intersected with resource.verbs, so inert permissions such as system.version:DELETE are pruned on boot.

🛡️ Roles, Credentials, and TOTP

  • Custom role lifecycle — POST, PATCH, and DELETE /auth/roles validate catalogued, served, grantable permissions before self-escalation checks. Builtin roles and assigned custom roles remain immutable or undeletable.
  • Credential expiry — Authentication filters credentials.expires_at in SQL and uses one injected clock instant for expiry and staleness. issue_token can now mint tokens with an explicit TTL.
  • Encrypted step-up — RFC 6238 TOTP uses an AES-GCM v1 envelope, an env-only 32-byte key, drift handling, and replay prevention. Enrollment is intentionally ungated; disabling it requires sudo.

🔄 Federated Login Without Rewriting Auth

  • Login exchange — POST /auth/oidc/login and GET /auth/oidc/callback implement authorization code plus PKCE. ID tokens reject bad signatures, issuers, audiences, expiry, nonces, and unsupported algorithms before provisioning.
  • Claims reconciliation — Each login refreshes role_mappings through sync_mapped_roles. Provider-owned assignments change with claims; local assignments survive. JIT provisioning links matching local usernames, with explicit refusals and warnings.
  • Deliberate boundary — OIDC is a login exchange, not a per-request authenticator. Authenticator, bearer middleware, resolve_principal, and the TUI stayed untouched; ansina-tui remains an external API client.

The access layer now fails closed by construction. 🔒

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