Reject invalid scan barrier keys

Author: lemon-mint

examples/kv/cmd/kvnode/main.go

@@ -257,11 +257,12 @@ func (s *service) handleScan(w http.ResponseWriter, r *http.Request) {
 		parts := strings.Split(raw, ",")
 		keys := make([][]byte, 0, len(parts))
 		for _, part := range parts {
-			if part == "" {
+			key := []byte(part)
+			if err := kv.ValidateKey(key); err != nil {
 				http.Error(w, "bad barrier key", http.StatusBadRequest)
 				return
 			}
-			keys = append(keys, []byte(part))
+			keys = append(keys, key)
 		}
 		if err := s.waitForKeys(r.Context(), keys...); err != nil {
 			http.Error(w, err.Error(), http.StatusServiceUnavailable)

examples/kv/cmd/kvnode/main_test.go

@@ -242,6 +242,8 @@ func TestHandleScanRejectsBadQueryAndMethod(t *testing.T) {
 		{name: "wrong method", method: http.MethodPost, target: "/scan", want: http.StatusMethodNotAllowed},
 		{name: "bad limit", method: http.MethodGet, target: "/scan?limit=many", want: http.StatusBadRequest},
 		{name: "bad reverse", method: http.MethodGet, target: "/scan?reverse=sideways", want: http.StatusBadRequest},
+		{name: "empty barrier part", method: http.MethodGet, target: "/scan?barrier=alpha,,beta", want: http.StatusBadRequest},
+		{name: "embedded separator barrier key", method: http.MethodGet, target: "/scan?barrier=alpha%00beta", want: http.StatusBadRequest},
 	}
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
@@ -251,6 +253,12 @@ func TestHandleScanRejectsBadQueryAndMethod(t *testing.T) {
 			if rr.Code != tc.want {
 				t.Fatalf("status=%d body=%q", rr.Code, rr.Body.String())
 			}
+			if tc.want == http.StatusBadRequest {
+				status := s.node.Status()
+				if len(status.Instances) != 0 || len(status.Executed) != 0 {
+					t.Fatalf("node status after rejected request: instances=%v executed=%v", status.Instances, status.Executed)
+				}
+			}
 		})
 	}
 }