Fix Luhn Operation to handle empty input

usdAG · Dec 13, 2024 · a209bc6 · a209bc6
1 parent a81e47b
commit a209bc6
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/main/java/de/usd/cstchef/operations/hashing/Luhn.java b/src/main/java/de/usd/cstchef/operations/hashing/Luhn.java
@@ -13,9 +13,12 @@ public class Luhn extends Operation {
     @Override
     protected ByteArray perform(ByteArray input, MessageType messageType) throws Exception {
 
+        String exceptionMessage = "Luhn can only be applied to numerical values.";
+        if(input.length() == 0) throw new IllegalArgumentException(exceptionMessage);
+
         for (int i = 0; i < input.length(); i++){
             if ((input.getByte(i) < '0') || (input.getByte(i) > '9')) {
-                throw new IllegalArgumentException("Luhn can only be applied to numerical values.");
+                throw new IllegalArgumentException(exceptionMessage);
             }
         }