1 files changed, 38 insertions, 0 deletions
diff --git a/lib/crypto/RollingChecksum.cpp b/lib/crypto/RollingChecksum.cpp
new file mode 100755
index 00000000..75bad7df
--- /dev/null
+++ b/lib/crypto/RollingChecksum.cpp
@@ -0,0 +1,38 @@
+// --------------------------------------------------------------------------
+//
+// File
+//		Name:    RollingChecksum.cpp
+//		Purpose: A simple rolling checksum over a block of data
+//		Created: 6/12/03
+//
+// --------------------------------------------------------------------------
+
+#include "Box.h"
+#include "RollingChecksum.h"
+
+#include "MemLeakFindOn.h"
+
+// --------------------------------------------------------------------------
+//
+// Function
+//		Name:    RollingChecksum::RollingChecksum(const void *, unsigned int)
+//		Purpose: Constructor -- does initial computation of the checksum.
+//		Created: 6/12/03
+//
+// --------------------------------------------------------------------------
+RollingChecksum::RollingChecksum(const void *data, unsigned int Length)
+	: a(0),
+	  b(0)
+{
+	uint8_t *block = (uint8_t *)data;
+	for(unsigned int x = Length; x >= 1; --x)
+	{
+		a += (*block);
+		b += x * (*block);
+		
+		++block;
+	}
+}
+
+
+