Update app.py

app.py

@@ -59,7 +59,7 @@ def swap_face(source_file, target_file, doFaceEnhancer, skey, key):
     skey = json.loads(skey)
     #first validate skey
     signature = base64.b64decode(skey["s"])
-    if not verify_signature(public_key, skey["t"] + "_" + key, signature):
+    if not skey or not key or not verify_signature(public_key, skey["t"] + "_" + key, signature):
         raise Exception("verify authkey failed.")
     timestamp_requested = int(skey["t"])
     timestamp_now = int(datetime.datetime.utcnow().replace(tzinfo=datetime.timezone.utc).timestamp())