fix DigestUtil by using unsigned int conversion

apache · Mar 16, 2018 · 1ba0e8b · 1ba0e8b
1 parent eacca90
commit 1ba0e8b
Showing 1 changed file with 15 additions and 3 deletions.
diff --git a/plc4j/protocols/ads/src/main/java/org/apache/plc4x/java/ads/protocol/util/DigestUtil.java b/plc4j/protocols/ads/src/main/java/org/apache/plc4x/java/ads/protocol/util/DigestUtil.java
@@ -23,7 +23,17 @@ Licensed to the Apache Software Foundation (ASF) under one
 
 public class DigestUtil {
 
-    private static CRC crc16 = new CRC(CRC.Parameters.CRC16);
+    public static final CRC.Parameters CRC16 = CRC.Parameters.CRC16;
+
+    public static final CRC.Parameters CRC16_ADS = new CRC.Parameters(
+        CRC16.getWidth(),
+        CRC16.getPolynomial(),
+        0xFFFF,
+        CRC16.isReflectIn(),
+        CRC16.isReflectOut(),
+        CRC16.getFinalXor());
+
+    private static CRC crc16 = new CRC(CRC16_ADS);
 
     private DigestUtil() {
         // Utility class
@@ -37,11 +47,13 @@ public static int calculateCrc16(ByteReadable... byteReadables) {
         for (ByteReadable byteReadable : byteReadables) {
             currentCrcValue = crc16.update(currentCrcValue, byteReadable.getBytes());
         }
-        return crc16.finalCRC16(currentCrcValue) & 0x0000FFFF;
+        short finalCrc = crc16.finalCRC16(currentCrcValue);
+        return Short.toUnsignedInt(finalCrc);
     }
 
     public static int calculateCrc16(byte[] bytes) {
-        return (int) crc16.calculateCRC(bytes) & 0x0000FFFF;
+        short crc = (short) crc16.calculateCRC(bytes);
+        return Short.toUnsignedInt(crc);
     }
 
 }