Fix KeyError in auth.py when password field is empty

demo/auth.py

@@ -74,31 +74,40 @@ def check_password() -> bool:
 
     def password_entered():
         """Check if entered password is correct."""
+        # Safely get password from session state
+        entered_password = st.session_state.get("password", "")
+
+        if not entered_password:
+            st.session_state["authenticated"] = False
+            st.session_state["password_incorrect"] = True
+            return
+
         # Get password(s) from secrets
         if "auth" in st.secrets:
             # Check single password
             if "password" in st.secrets["auth"]:
                 if hmac.compare_digest(
-                    st.session_state["password"],
+                    entered_password,
                     st.secrets["auth"]["password"]
                 ):
                     st.session_state["authenticated"] = True
                     st.session_state["username"] = "user"
-                    del st.session_state["password"]
+                    if "password" in st.session_state:
+                        del st.session_state["password"]
                     return
 
             # Check multiple users
             if "passwords" in st.secrets["auth"]:
                 username = st.session_state.get("username_input", "")
-                password = st.session_state.get("password", "")
 
                 passwords = st.secrets["auth"]["passwords"]
                 if username in passwords and hmac.compare_digest(
-                    password, passwords[username]
+                    entered_password, passwords[username]
                 ):
                     st.session_state["authenticated"] = True
                     st.session_state["username"] = username
-                    del st.session_state["password"]
+                    if "password" in st.session_state:
+                        del st.session_state["password"]
                     return
 
         st.session_state["authenticated"] = False