securite: #87 T3 cookies Secure centralises + CORS atteste (defaut inchange)

backend/auth/router.py

@@ -5,6 +5,7 @@
 import base64
 import binascii
 import logging
+import os
 import re
 
 from fastapi import APIRouter, Body, Depends, HTTPException, Request, Response
@@ -56,6 +57,17 @@ logger = logging.getLogger("obsigate.auth.router")
 router = APIRouter(prefix="/api/auth", tags=["auth"])
 
 
+def is_secure_cookies() -> bool:
+    """True when auth cookies must carry the ``Secure`` flag (#87 T3).
+
+    Opt-in via ``OBSIGATE_SECURE_COOKIES=true`` (required behind TLS).
+    Default stays ``false`` so logins keep working over plain HTTP on
+    trusted loopback deployments — browsers drop ``Secure`` cookies sent
+    over HTTP, which would silently break localhost logins.
+    """
+    return os.environ.get("OBSIGATE_SECURE_COOKIES", "false").lower() == "true"
+
+
 # ── Pydantic request models ──────────────────────────────────────────
 
 class LoginRequest(BaseModel):
@@ -229,9 +241,8 @@ def _issue_tokens(user: dict, username: str, remember_me: bool, response: Respon
     access_token = create_access_token(user)
     refresh_token, refresh_jti = create_refresh_token(username, remember=remember_me)
 
-    import os
     max_age = 2592000 if remember_me else 604800  # 30d or 7d
-    secure = os.environ.get("OBSIGATE_SECURE_COOKIES", "false").lower() == "true"
+    secure = is_secure_cookies()
     response.set_cookie(
         key="refresh_token",
         value=refresh_token,
@@ -300,9 +311,7 @@ async def refresh_token_endpoint(request: Request, response: Response):
         if stale:
             raise HTTPException(401, "Session expirée, veuillez vous reconnecter")
 
-    import os
-
-    secure = os.environ.get("OBSIGATE_SECURE_COOKIES", "false").lower() == "true"
+    secure = is_secure_cookies()
     remember_me = bool(payload.get("remember", False))
 
     # BUG-027: rotate the refresh token — the old one is now single-use.