feat(link_codes): linking method between telegram and website

core/deps.py

@@ -3,9 +3,11 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from config import cfg
 from core.auth import jwt
+from core.secrets import get_kid_from_token
 from db.session import get_db
 from external.pally import PallyClient
-from schemas.dto import AuthContext
+from repositories.service_signatures import get_active_signature_by_kid
+from schemas.dto import AuthContext, ServiceIdentity
 from services.subscriptions import sync_user_subscription
 
 
@@ -25,5 +27,21 @@ async def get_auth_context(
         return ctx
 
 
+async def get_service_identity(
+    request: Request, session: AsyncSession = Depends(get_db)
+) -> ServiceIdentity | None:
+    auth = request.headers.get("Authorization")
+
+    if auth.startswith("Bearer"):
+        token = auth.removeprefix("Bearer ").strip()
+        kid = get_kid_from_token(token)
+        if not kid:
+            raise HTTPException(401, detail="No kid provided.")
+        signature = await get_active_signature_by_kid(session, kid)
+        if not signature:
+            raise HTTPException(401, detail="Invalid signature")
+        return ServiceIdentity(service=signature.kid)
+
+
 def get_pally_client() -> PallyClient:
     return PallyClient(api_token=cfg.pally_token, payer_pays_commission=True)