Bugfix: prevent checksum computation errors mvillalba#25

SamyCookie · Apr 3, 2015 · 7cf7dca · 7cf7dca
1 parent 4385a18
commit 7cf7dca
Showing 1 changed file with 4 additions and 7 deletions.
diff --git a/src/ant/core/message.py b/src/ant/core/message.py
@@ -61,14 +61,11 @@ def setType(self, type_):
         self.type_ = type_
 
     def getChecksum(self):
-        data = chr(len(self.getPayload()))
-        data += chr(self.getType())
-        data += self.getPayload()
-
         checksum = MESSAGE_TX_SYNC
-        for byte in data:
-            checksum = (checksum ^ ord(byte)) % 0xFF
-
+        checksum ^= len(self.payload)
+        checksum ^= self.type_
+        for byte in self.payload:
+            checksum = (checksum ^ ord(byte)) & 0xFF
         return checksum
 
     def getSize(self):