feat: validation locale du jeton draco_session — repli SSO dans get_current_user (#217)

backend/auth/middleware.py

@@ -9,6 +9,7 @@ import sys
 from fastapi import Depends, HTTPException, Request
 from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
 
+from backend import draco_session
 from backend.services.net import get_client_ip
 
 from .jwt_handler import decode_token, is_token_revoked, maybe_touch_api_token
@@ -86,20 +87,22 @@ def get_current_user(
         token = request.cookies["access_token"]
 
     if not token:
-        return None
+        return _draco_fallback(request)
 
     payload = decode_token(token)
     if not payload or payload.get("type") != "access":
-        return None
+        return _draco_fallback(request)
 
     # BUG-027: access tokens revoked at logout must be rejected immediately.
+    # (Le repli draco reste sûr : la déconnexion globale révoque aussi
+    # le jti draco et efface son cookie.)
     jti = payload.get("jti")
     if jti and is_token_revoked(jti):
-        return None
+        return _draco_fallback(request)
 
     user = get_user(payload["sub"])
     if not user or not user.get("active"):
-        return None
+        return _draco_fallback(request)
 
     # BUG-028: a password change invalidates every token issued before it.
     pca = user.get("password_changed_at")
@@ -107,9 +110,9 @@ def get_current_user(
     if pca is not None and iat is not None:
         try:
             if int(iat) < int(float(pca)):
-                return None
+                return _draco_fallback(request)
         except (TypeError, ValueError):
-            return None
+            return _draco_fallback(request)
 
     # Attach vault permissions from the token (snapshot at login time)
     user["_token_vaults"] = payload.get("vaults", [])
@@ -127,6 +130,17 @@ def get_current_user(
     return user
 
 
+def _draco_fallback(request: Request) -> dict | None:
+    """Fusion ACC-3.2 (#9) : à défaut de jeton natif valide, le cookie
+    partagé draco_session authentifie l'utilisateur (sub = id
+    ObsiGate, correspondance directe — voir draco_session.user_for_draco).
+    """
+    user = draco_session.user_for_draco(request)
+    if user is not None:
+        user["_request_ip"] = get_client_ip(request)
+    return user
+
+
 def require_auth(current_user=Depends(get_current_user)):
     """Dependency: require a valid authenticated user."""
     if not current_user:

backend/draco_session.py

@@ -175,6 +175,46 @@ def clear_cookie(response) -> None:
     response.delete_cookie(COOKIE_NAME, path="/", **extra)
 
 
+# ── Validation locale (ACC-3.2, #9) ─────────────────────────────────────
+
+def user_for_draco(request) -> dict | None:
+    """Utilisateur ObsiGate prouvé par le cookie draco_session.
+
+    ObsiGate est à la fois émettrice et consommatrice : le `sub` du
+    jeton EST son identifiant d'utilisateur — la correspondance est
+    directe, par id. Le garde-fou « jeton antérieur au dernier
+    changement de mot de passe » (BUG-028 côté natif) est appliqué
+    à l'identique via le claim `iat`.
+    """
+    claims = verify_token(request.cookies.get(COOKIE_NAME, ""))
+    if not claims:
+        return None
+    sub = str(claims.get("sub", ""))
+    if not sub:
+        return None
+    from backend.auth.user_store import get_all_users
+
+    for candidate in get_all_users():
+        if str(candidate.get("id")) != sub:
+            continue
+        if not candidate.get("active"):
+            return None
+        pca = candidate.get("password_changed_at")
+        iat = claims.get("iat")
+        if pca is not None and iat is not None:
+            try:
+                if int(iat) < int(float(pca)):
+                    return None
+            except (TypeError, ValueError):
+                return None
+        user = dict(candidate)
+        user["_token_vaults"] = candidate.get("vaults", [])
+        user["_token_scope"] = "full"
+        user["_draco_sub"] = sub
+        return user
+    return None
+
+
 # ── Renouvellement glissant (middleware) ────────────────────────────────
 
 class DracoRenewalMiddleware: