Fix security

backend/app/api/v1/marathons.py

@@ -1,7 +1,8 @@
 from datetime import timedelta
 import secrets
 import string
-from fastapi import APIRouter, HTTPException, status
+from fastapi import APIRouter, HTTPException, status, Depends
+from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
 from sqlalchemy import select, func
 from sqlalchemy.orm import selectinload
 
@@ -10,6 +11,10 @@ from app.api.deps import (
     require_participant, require_organizer, require_creator,
     get_participant,
 )
+from app.core.security import decode_access_token
+
+# Optional auth for endpoints that need it conditionally
+optional_auth = HTTPBearer(auto_error=False)
 from app.models import (
     Marathon, Participant, MarathonStatus, Game, GameStatus, Challenge,
     Assignment, AssignmentStatus, Activity, ActivityType, ParticipantRole,
@@ -188,6 +193,15 @@ async def create_marathon(
 async def get_marathon(marathon_id: int, current_user: CurrentUser, db: DbSession):
     marathon = await get_marathon_or_404(db, marathon_id)
 
+    # For private marathons, require participation (or admin/creator)
+    if not marathon.is_public and not current_user.is_admin:
+        participation = await get_participation(db, current_user.id, marathon_id)
+        if not participation:
+            raise HTTPException(
+                status_code=status.HTTP_403_FORBIDDEN,
+                detail="You are not a participant of this private marathon",
+            )
+
     # Count participants and approved games
     participants_count = await db.scalar(
         select(func.count()).select_from(Participant).where(Participant.marathon_id == marathon_id)
@@ -428,7 +442,16 @@ async def join_public_marathon(marathon_id: int, current_user: CurrentUser, db:
 
 @router.get("/{marathon_id}/participants", response_model=list[ParticipantWithUser])
 async def get_participants(marathon_id: int, current_user: CurrentUser, db: DbSession):
-    await get_marathon_or_404(db, marathon_id)
+    marathon = await get_marathon_or_404(db, marathon_id)
+
+    # For private marathons, require participation (or admin)
+    if not marathon.is_public and not current_user.is_admin:
+        participation = await get_participation(db, current_user.id, marathon_id)
+        if not participation:
+            raise HTTPException(
+                status_code=status.HTTP_403_FORBIDDEN,
+                detail="You are not a participant of this private marathon",
+            )
 
     result = await db.execute(
         select(Participant)
@@ -497,8 +520,42 @@ async def set_participant_role(
 
 
 @router.get("/{marathon_id}/leaderboard", response_model=list[LeaderboardEntry])
-async def get_leaderboard(marathon_id: int, db: DbSession):
-    await get_marathon_or_404(db, marathon_id)
+async def get_leaderboard(
+    marathon_id: int,
+    db: DbSession,
+    credentials: HTTPAuthorizationCredentials | None = Depends(optional_auth),
+):
+    """
+    Get marathon leaderboard.
+    Public marathons: no auth required.
+    Private marathons: requires auth + participation check.
+    """
+    marathon = await get_marathon_or_404(db, marathon_id)
+
+    # For private marathons, require authentication and participation
+    if not marathon.is_public:
+        if not credentials:
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Authentication required for private marathon leaderboard",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+
+        payload = decode_access_token(credentials.credentials)
+        if not payload:
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Invalid or expired token",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+
+        user_id = int(payload.get("sub"))
+        participant = await get_participant(db, user_id, marathon_id)
+        if not participant:
+            raise HTTPException(
+                status_code=status.HTTP_403_FORBIDDEN,
+                detail="You are not a participant of this marathon",
+            )
 
     result = await db.execute(
         select(Participant)