Fix rate limiting

backend/routes/account.py

@@ -18,7 +18,7 @@ import os
 from security.audit import log_security
 from security.profanity import contains_profanity
 from security.user_agent_blocklist import is_user_agent_blocked
-from security.rate_limit import rate_limit_per_ip, rate_limit_per_user
+from security.rate_limit import rate_limit_per_ip
 router = APIRouter()
 
 _FAILED_ATTEMPT_WINDOW_SECONDS = 300
@@ -445,7 +445,7 @@ def logout(
 
 
 @router.post("/change-password")
-@rate_limit_per_user("5/hour")
+@rate_limit_per_ip("5/hour")
 def change_password(
     request: Request,
     password_request: ChangePasswordRequest,
@@ -487,7 +487,8 @@ def change_password(
 
 
 @router.get("/users")
-def list_users(current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
+@rate_limit_per_ip("30/minute")  # Per-IP limit to prevent abuse
+def list_users(request: Request, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
     users = db.query(User).order_by(User.username.asc()).all()
     return {
         "users": [
@@ -497,13 +498,15 @@ def list_users(current_user: User = Depends(get_current_user), db: Session = Dep
 
 
 @router.get("/crypto/public-key/of/{user_id}")
-def get_public_key_of(user_id: int, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
+@rate_limit_per_ip("100/minute")  # Per-IP limit to prevent abuse
+def get_public_key_of(request: Request, user_id: int, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
     row = db.query(CryptoPublicKey).filter(CryptoPublicKey.user_id == user_id).first()
     return {"publicKey": row.public_key_b64 if row else None}
 
 
 @router.get("/users/search")
-def search_users(q: str, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
+@rate_limit_per_ip("60/minute")  # Per-IP limit to prevent abuse
+def search_users(request: Request, q: str, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
     if len(q.strip()) < 2:
         return {"users": []}
     

backend/routes/messaging.py

@@ -27,7 +27,7 @@ import json
 from better_profanity import profanity as _bp
 from security.audit import log_access, log_dm, log_public_chat, log_security
 from security.profanity import censor_text
-from security.rate_limit import rate_limit_per_user
+from security.rate_limit import rate_limit_per_ip
 
 router = APIRouter()
 logger = logging.getLogger("uvicorn.error")
@@ -386,7 +386,7 @@ async def _send_message_internal(
 
 
 @router.post("/send_message")
-@rate_limit_per_user("30/minute")
+@rate_limit_per_ip("30/minute")
 async def send_message(
     request: Request,
     message_request: SendMessageRequest | None = None,
@@ -414,7 +414,8 @@ async def send_message(
 
 
 @router.get("/get_messages")
-async def get_messages(db: Session = Depends(get_db)):
+@rate_limit_per_ip("60/minute")  # Per-IP limit to prevent abuse
+async def get_messages(request: Request, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
     messages = db.query(Message).order_by(Message.timestamp.asc()).all()
 
     messages_data = []
@@ -428,7 +429,7 @@ async def get_messages(db: Session = Depends(get_db)):
 
 
 @router.post("/dm/send")
-@rate_limit_per_user("20/minute")
+@rate_limit_per_ip("20/minute")
 async def dm_send(
     request: Request,
     payload: dict | None = None,
@@ -578,7 +579,8 @@ def convert_envelopes(envs: list[DMEnvelope]):
     }
 
 @router.get("/dm/fetch")
-async def dm_fetch(since: int | None = None, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
+@rate_limit_per_ip("60/minute")  # Per-IP limit to prevent abuse
+async def dm_fetch(request: Request, since: int | None = None, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
     q = db.query(DMEnvelope).filter(DMEnvelope.recipient_id == current_user.id)
     if since:
         q = q.filter(DMEnvelope.id > since)
@@ -586,7 +588,8 @@ async def dm_fetch(since: int | None = None, current_user: User = Depends(get_cu
 
 
 @router.get("/dm/history/{other_user_id}")
-async def dm_history(other_user_id: int, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
+@rate_limit_per_ip("60/minute")  # Per-IP limit to prevent abuse
+async def dm_history(request: Request, other_user_id: int, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
     return convert_envelopes(
         db.query(DMEnvelope)
         .filter(
@@ -599,7 +602,8 @@ async def dm_history(other_user_id: int, current_user: User = Depends(get_curren
 
 
 @router.get("/dm/conversations")
-async def get_dm_conversations(current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
+@rate_limit_per_ip("60/minute")  # Per-IP limit to prevent abuse
+async def get_dm_conversations(request: Request, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
     # Get all DM conversations where current user is involved
     conversations_query = db.query(DMEnvelope).filter(
         (DMEnvelope.sender_id == current_user.id) | (DMEnvelope.recipient_id == current_user.id)
@@ -641,7 +645,7 @@ async def get_dm_conversations(current_user: User = Depends(get_current_user), d
 
 
 @router.put("/edit_message/{message_id}")
-@rate_limit_per_user("20/minute")
+@rate_limit_per_ip("20/minute")
 async def edit_message(
     request: Request,
     message_id: int,
@@ -718,7 +722,7 @@ async def delete_message(
 
 
 @router.post("/add_reaction")
-@rate_limit_per_user("50/minute")
+@rate_limit_per_ip("50/minute")
 async def add_reaction(
     request: Request,
     reaction_request: ReactionRequest,
@@ -787,7 +791,7 @@ async def add_reaction(
 
 
 @router.post("/dm/add_reaction")
-@rate_limit_per_user("50/minute")
+@rate_limit_per_ip("50/minute")
 async def add_dm_reaction(
     request: Request,
     reaction_request: DMReactionRequest,

backend/routes/profile.py

@@ -17,7 +17,7 @@ from similarity import is_user_similar_to_verified
 from .messaging import messagingManager
 from security.audit import log_security
 from security.profanity import contains_profanity
-from security.rate_limit import rate_limit_per_user
+from security.rate_limit import rate_limit_per_ip
 
 router = APIRouter()
 
@@ -41,7 +41,7 @@ PROFILE_PICTURES_DIR = Path("data/uploads/pfp")
 os.makedirs(PROFILE_PICTURES_DIR, exist_ok=True)
 
 @router.post("/upload-profile-picture")
-@rate_limit_per_user("10/minute")
+@rate_limit_per_ip("10/minute")
 async def upload_profile_picture(
     request: Request,
     profile_picture: UploadFile = File(...),
@@ -167,7 +167,7 @@ async def list_users(
     }
 
 @router.put("/user/profile")
-@rate_limit_per_user("10/minute")
+@rate_limit_per_ip("10/minute")
 async def update_user_profile(
     request: Request,
     update_request: UpdateProfileRequest,
@@ -245,7 +245,7 @@ async def update_user_profile(
 
 
 @router.put("/user/bio")
-@rate_limit_per_user("10/minute")
+@rate_limit_per_ip("10/minute")
 async def update_user_bio(
     request: Request,
     bio_request: UpdateBioRequest,

backend/security/rate_limit.py

@@ -4,43 +4,24 @@ from typing import Callable
 from fastapi import Request
 from slowapi import Limiter
 from slowapi.util import get_remote_address
-from slowapi.errors import RateLimitExceeded
 
 from utils import get_client_ip
 
-# Initialize limiter with IP-based key function
-limiter = Limiter(
-    key_func=lambda request: get_client_ip(request) or get_remote_address(request),
-    default_limits=["1000/hour"],  # Global default limit
-    storage_uri="memory://",  # In-memory storage (can be changed to Redis later)
-)
-
-
-def get_user_id_key(request: Request) -> str:
-    """Get rate limit key based on authenticated user ID."""
-    user = getattr(getattr(request, "state", None), "current_user", None)
-    if user and hasattr(user, "id"):
-        return f"user:{user.id}"
-    # Fallback to IP if not authenticated
-    return get_client_ip(request) or get_remote_address(request)
-
-
 def get_ip_key(request: Request) -> str:
     """Get rate limit key based on IP address."""
     return get_client_ip(request) or get_remote_address(request)
 
+# Initialize limiter with IP-based key function
+# Note: We don't set default_limits to avoid affecting all users if one IP is attacked.
+# Each endpoint should have an explicit rate limit based on its sensitivity.
+limiter = Limiter(
+    key_func=get_ip_key,
+    default_limits=[],  # No global default - each endpoint must have explicit limits
+    storage_uri="memory://",  # In-memory storage (can be changed to Redis later)
+)
 
-# Rate limit decorators for different endpoint types
+
+# Rate limit decorator for IP-based limiting
 def rate_limit_per_ip(limit: str) -> Callable:
     """Rate limit based on IP address."""
     return limiter.limit(limit, key_func=get_ip_key)
-
-
-def rate_limit_per_user(limit: str) -> Callable:
-    """Rate limit based on authenticated user ID, fallback to IP.
-    
-    Note: The user must be authenticated (get_current_user dependency must run first).
-    The user will be available in request.state.current_user after authentication.
-    """
-    return limiter.limit(limit, key_func=get_user_id_key)
-