Create utils/security.py

utils/security.py

@@ -0,0 +1,30 @@
+import time
+import hmac
+import hashlib
+from fastapi import HTTPException
+
+REQUEST_LOG = {}
+WINDOW_SECONDS = 10
+MAX_REQUESTS = 6
+
+
+def rate_limit(ip):
+    t = time.time()
+    entries = REQUEST_LOG.get(ip, [])
+    entries = [x for x in entries if t - x < WINDOW_SECONDS]
+
+    if len(entries) >= MAX_REQUESTS:
+        raise HTTPException(
+            status_code=429,
+            detail="Too many requests."
+        )
+
+    REQUEST_LOG[ip] = entries + [t]
+
+
+def sign_payload(payload, secret):
+    return hmac.new(
+        secret.encode(),
+        payload.encode(),
+        hashlib.sha256
+    ).hexdigest()