missions/_docs/00_problem/security_approach.md

# Security Approach — Azaion.Missions

> **Status**: derived-from-code (autodev `/document` Step 6, 2026-05-14).
> All claims below trace to actual code, configuration, or a tracked suite-level finding. Items called out as "currently divergent" are intentional carry-forward — see `_docs/02_document/architecture.md` § 8 ADRs and `00_discovery.md` § Spec ↔ Code Divergences.

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## 1. Authentication

**Mechanism**: JWT bearer (**ECDSA-SHA256**) with public-key validation against `admin`'s JWKS endpoint. After the first successful JWKS fetch, request-path validation is purely local (no per-request call to `admin`).

**Trust model**: `admin` holds the ECDSA **private** key; every backend service on each edge device validates with the corresponding **public** keys, fetched from `admin`'s JWKS endpoint (`JWT_JWKS_URL`). Rotation publishes a new `kid` in the JWKS; consumers pick it up at the next refresh tick — **NO coordinated redeploy** required (one of the primary operational wins over the legacy HS256 model).

**Validation parameters** (`Auth/JwtExtensions.cs`):

| Parameter | Value | Notes |
|-----------|-------|-------|
| `ValidAlgorithms` | `[SecurityAlgorithms.EcdsaSha256]` | Algorithm pin — defends against HS256-confusion attacks (an attacker who learns the JWKS public key cannot forge tokens signed with `alg: HS256` using that key as the HMAC secret) |
| `IssuerSigningKeyResolver` | Pulls keys from cached `JsonWebKeySet` retrieved via `ConfigurationManager<JsonWebKeySet>` | Lazily fetches on first protected request; cache refreshes on the manager's default schedule matched against admin's `Cache-Control: public, max-age=3600` |
| JWKS HTTP transport | `HttpDocumentRetriever { RequireHttps = true }` | HTTPS-only — a misconfigured `JWT_JWKS_URL = http://...` fails at fetch time, not at startup config resolution |
| `ValidateLifetime` | `true` | Tokens with `exp` in the past are rejected |
| `ClockSkew` | `TimeSpan.FromSeconds(30)` | Tighter than .NET's 5-min default AND tighter than the legacy 1-min setting |
| `ValidateIssuer` | **`true`** with `ValidIssuer = <resolved JWT_ISSUER>` | **CMMC L2 row 3 finding structurally fixed in this service's code.** Suite-level docs may still describe the legacy "disabled" model and have a separate sync task pending |
| `ValidateAudience` | **`true`** with `ValidAudience = <resolved JWT_AUDIENCE>` | Same as above |
| `ValidateIssuerSigningKey` | `true` (implicit via `IssuerSigningKeyResolver`) | Required for asymmetric validation |

**Failure outcomes**:

| Condition | HTTP code |
|-----------|-----------|
| Missing `Authorization` header on `[Authorize]` route | 401 |
| Invalid signature (no public key in cached JWKS verifies the token) | 401 |
| Token `kid` not in cached JWKS (rotation lag before refresh tick) | 401 (resolved on next JWKS refresh) |
| Token `alg` ∉ `[EcdsaSha256]` (e.g. forged `alg: HS256`) | 401 (algorithm pin) |
| Expired token (with 30s skew) | 401 |
| `iss` claim ≠ `JWT_ISSUER` | 401 |
| `aud` claim ≠ `JWT_AUDIENCE` | 401 |
| Valid signature + lifetime + iss + aud, but missing `permissions=FL` claim | 403 |
| `JWT_JWKS_URL` uses `http://` (not `https://`) | 500 on first protected request (HTTPS-only retriever throws); NOT caught at startup |
| `admin` unreachable AT the time of the first protected request after cold start | 500 on that first request (synchronous JWKS fetch fails); resolves once admin is reachable |

**`admin` outage AFTER JWKS cached**: tokens issued before the outage continue to validate locally against the cached public keys. This service does **not** require `admin` to be reachable for any request-path flow once the JWKS cache is warm. Once issued tokens expire, new logins fail at `admin`'s end (UI concern), but this service stays up until the cache itself expires and a refresh fails.

**`admin` outage AT cold start**: the first protected request triggers a synchronous JWKS HTTPS GET; if `admin` is unreachable at that moment, the request fails 500. This is a **new failure mode** introduced by the ECDSA-JWKS switch and is the cost of the rotation-without-redeploy operational win.

## 2. Authorization

**Single named policy**: `"FL"`. Every controller action in `01_vehicle_catalog` and `02_mission_planning` carries `[Authorize(Policy = "FL")]`. The policy is built as `AuthorizationPolicyBuilder.RequireClaim("permissions", "FL")` — satisfied when ANY `permissions` claim on the principal equals `"FL"`. A multi-permission token (`permissions: ["FL", "SOMETHING_ELSE"]`) is accepted.

**Role → permission matrix** is suite-level (`../../suite/_docs/00_roles_permissions.md`); this service does NOT enforce roles, only the `FL` permission.

**No per-method authz**: every protected endpoint has the same gate. There is no notion of "read-only operator" vs "full-access operator" inside this service.

**Hardcoded policy name carries legacy wording**: the string `"FL"` (originally "Flight") survives the rename to `missions`. Renaming the permission code is a fleet-wide auth change (would invalidate every issued token until new ones are minted) and is **NOT** in this Epic. Tracked as a TODO in `../../suite/_docs/00_roles_permissions.md`.

**Typo risk**: the `"FL"` string is repeated in feature controllers as a raw string. A typo silently turns into a permanent 403 with no compile-time detection. Mitigation: code review + the `module-layout.md` § Verification Needed #4 entry.

**No per-user attribution / audit**: the JWT's `sub` / user-id claim is parsed by `JwtBearerHandler` into `ClaimsPrincipal`, but nothing in this service consumes it. Logs are timestamp-only — incident reconstruction requires correlation by request time, not by user.

## 3. Data protection

**At rest**: PostgreSQL on-disk encryption is the device-level concern (suite-level, NOT this service). This service does NOT encrypt data at the column level.

**In transit**:

- The container `EXPOSE 8080` is **plain HTTP**. TLS termination is handled by the suite's edge reverse proxy (per `../../suite/_docs/00_top_level_architecture.md`).
- No `app.UseHttpsRedirection()` in this service. If the reverse proxy is misconfigured or absent, traffic between the operator UI and this service may be cleartext on the local edge network.

**Secrets management**:

- This service no longer holds a JWT signing secret. It holds **only** public-key configuration (`JWT_ISSUER`, `JWT_AUDIENCE`, `JWT_JWKS_URL`) plus `DATABASE_URL`. Whichever side gets compromised, that compromise no longer affects token signing.
- All four required values (`DATABASE_URL`, `JWT_ISSUER`, `JWT_AUDIENCE`, `JWT_JWKS_URL`) are resolved through `Infrastructure/ConfigurationResolver.cs` → `ResolveRequiredOrThrow` (env-var-first, then `IConfiguration` key, else THROW). **No hardcoded dev fallbacks** — the ADR-005 "dev fallback secret silently accepted in production" failure mode is structurally eliminated. ADR-005 now only covers the unconditional-Swagger branch.
- No secret manager (Vault, AWS SM, K8s Secrets) — config values are baked into the device's docker compose env at provisioning time.

## 4. Input validation

**None at the application layer**. No `[Required]`, no `[Range]`, no min-length attributes; no custom validators. The following are all accepted by ASP.NET Core model binding without rejection:

| Bad input | Accepted today |
|-----------|---------------|
| `CreateVehicleRequest.Name = ""` | yes |
| `CreateVehicleRequest.BatteryCapacity = -1` | yes |
| `CreateVehicleRequest.Type = (VehicleType)999` | yes — int casts to enum without range check |
| `CreateWaypointRequest.OrderNum = -1` | yes |
| `CreateWaypointRequest.GeoPoint = null` (or all three of `Lat`/`Lon`/`Mgrs` null) | yes |
| `GetMissionsQuery.Page = -1` / `PageSize = 1_000_000` | yes — no bounds |

This is a **carry-forward concern** — input-shape testing is not a security gate today; the threat surface is mitigated by the closed edge network and authenticated single-operator workflow. Tightening is on the autodev backlog (Phase B feature cycle).

## 5. CORS

**Gated by `Infrastructure/CorsConfigurationValidator.cs`** at startup:

- In `Production` (case-insensitive match on `ASPNETCORE_ENVIRONMENT`): startup **THROWS `InvalidOperationException`** when `CorsConfig:AllowedOrigins` is empty AND `CorsConfig:AllowAnyOrigin != true`. The "open in all environments" failure mode is structurally eliminated.
- In non-Production environments: the same empty allow-list with `AllowAnyOrigin=false` falls back to permissive (`AllowAnyOrigin/Method/Header`) AND emits a `PermissiveDefaultWarning` startup log. The pre-B11 "all environments permissive" assumption no longer holds.
- An explicit `AllowedOrigins` list narrows CORS to those origins in every environment.

The closed edge network behind the suite reverse proxy is still the deployment-shape backstop, but the application now refuses to start in production without an explicit policy decision.

## 6. Production-deploy footguns

These are explicit security-relevant risks the code carries today, all tracked at the suite level or as carry-forward:

| Footgun | Where | Mitigation |
|---------|-------|------------|
| **Cold-start dependency on `admin` reachability**: first protected request after a cold start triggers a synchronous JWKS HTTPS GET against `JWT_JWKS_URL`. If `admin` is unreachable at that moment, the request fails 500. Once cached, request-path is local-only | `Auth/JwtExtensions.cs` `ConfigurationManager<JsonWebKeySet>` | Document operational expectation; consider pre-warming the JWKS cache during startup if cold-start failure modes become disruptive |
| **`JWT_JWKS_URL` misconfigured as `http://`** passes startup config resolution but fails at first JWKS fetch → 500 | `Auth/JwtExtensions.cs` `HttpDocumentRetriever { RequireHttps = true }` | Detected at runtime, not startup; recommend a startup smoke check that validates the URL scheme before serving traffic |
| **Swagger UI mounted unconditionally** | `Program.cs` (no `IsDevelopment` gate, ADR-005 surviving branch) | Reverse-proxy-level allowlist on `/swagger` is the suite-level mitigation; verify on first production rollout |
| **CORS allow-list empty in non-Production** falls back to permissive (`AllowAnyOrigin/Method/Header`) with a startup warning | `Infrastructure/CorsConfigurationValidator.cs` | Document explicit `CorsConfig:AllowedOrigins` for staging/dev too if permissive is undesirable. **Production fails-fast** — no remediation needed there |
| **No HTTPS redirection** | `Program.cs` (no `app.UseHttpsRedirection()`) | Reverse proxy enforces TLS upstream |
| **Stack trace logged for unhandled 500s** | `Middleware/ErrorHandlingMiddleware.cs` `LogError(ex, ...)` | Stack is logged only — NOT returned in the HTTP response body (the 500 body is the generic `"Internal server error"` message from middleware) |
| **Cascade-delete is NOT transaction-wrapped** (data-integrity, not auth) | `Services/MissionService.cs`, `Services/WaypointService.cs` (ADR-006) | One-line fix queued; recommended to land with B6 |
| **Hardcoded permission string `"FL"`** in feature controllers | `Controllers/{Vehicles,Missions}Controller.cs` | Risk: typo silently turns into permanent 403; mitigation by code review + `module-layout.md` |
| **Permission code `"FL"` retains legacy "Flight" wording** post-rename | `Auth/JwtExtensions.cs` | Fleet-wide auth change deferred (not in this Epic); TODO in `../../suite/_docs/00_roles_permissions.md` |

**Removed from this list** (previously listed, now structurally fixed by code, not by mitigation):

- ❌ Dev fallback for `JWT_SECRET` — `JWT_SECRET` env var is no longer consulted; the resolver throws on missing required config.
- ❌ Dev fallback for `DATABASE_URL` — same resolver throws on missing required config.
- ❌ CORS `AllowAnyOrigin/Method/Header` in production — production startup throws on empty allow-list with `AllowAnyOrigin != true`.
- ❌ JWT `iss`/`aud` validation disabled — both are now validated; CMMC L2 row 3 finding structurally fixed in this service's code.

## 7. Audit logging

**None at the application level today.** The only structured log emitted by application code is `_logger.LogError(ex, "Unhandled exception")` in `ErrorHandlingMiddleware` for 500s. There is:

- **No correlation ID** per request
- **No per-user attribution** (the JWT user-id claim is not consumed)
- **No security-event log** (auth failures are logged by `JwtBearerHandler` at default ASP.NET Core levels — typically Information, not surfaced as a dedicated audit channel)
- **No data-access audit** (writes/deletes go directly through linq2db with no wrapper that emits an audit row)

Production incident response on this service today requires grep-by-timestamp correlation against the operator UI's logs and `admin`'s issuance logs.

## 8. Threat model summary (one-paragraph)

The deployment shape — closed edge network, single operator per device, suite reverse proxy enforcing TLS and origin allowlisting upstream, Watchtower restart on crash — remains the primary defence-in-depth layer, but the application-layer auth posture has materially improved: ECDSA-SHA256 JWT validation against `admin`'s JWKS (with algorithm pinning, `iss`/`aud` validation, HTTPS-only JWKS fetch, and a 30s clock skew), production-gated CORS, and fail-fast required-config resolution have collectively eliminated the dev-fallback, iss/aud-disabled, and CORS-permissive-in-prod footguns that the legacy HS256 model carried. Residual application-level weak points (no input validation, no per-user audit, hardcoded `"FL"` string, cold-start dependency on `admin` reachability for the first protected request, non-transactional cascade delete) are documented and tracked. The CMMC L2 row 3 finding is structurally closed in this service's code; suite-level documentation may still describe the legacy posture and has a separate sync task pending.

## 9. References

| Concern | File |
|---------|------|
| Auth registration | `Auth/JwtExtensions.cs` |
| Authorization attribute usage | `Controllers/AircraftsController.cs` (post-B6: `VehiclesController.cs`), `Controllers/FlightsController.cs` (post-B6: `MissionsController.cs`) |
| Error envelope (no stack-leak) | `Middleware/ErrorHandlingMiddleware.cs` |
| Env / config resolution (fail-fast) | `Program.cs`, `Infrastructure/ConfigurationResolver.cs` |
| CORS validation | `Infrastructure/CorsConfigurationValidator.cs` |
| CMMC L2 scorecard | `../../suite/_docs/05_security/cmmc_l2_scorecard.md` |
| Roles & `FL` permission origin | `../../suite/_docs/00_roles_permissions.md` |
| ADR-005 (Swagger unconditional, surviving branch) | `_docs/02_document/architecture.md` § 8 |
| ADR-002 (PascalCase wire shape) | `_docs/02_document/architecture.md` § 8 |
| Component identity description | `_docs/02_document/components/05_identity/description.md` |
| Component http-conventions description | `_docs/02_document/components/06_http_conventions/description.md` |