Security-55471.tar.gz

[apple/security.git] / utilities / src / comparison.c

diff --git a/utilities/src/comparison.c b/utilities/src/comparison.c
new file mode 100644 (file)
index 0000000..d0d287d
--- /dev/null
+++ b/utilities/src/comparison.c
@@ -0,0 +1,19 @@
+//
+//  comparison.c
+//  utilities
+//
+//  Created by Keith Henrickson on 7/1/12.
+//  Copyright (c) 2012 Apple Inc. All rights reserved.
+//
+
+#include <stdio.h>
+#include <stdint.h>
+#include "comparison.h"
+
+uint64_t constant_memcmp(const uint8_t *first, const uint8_t *second, size_t count) {
+    uint64_t error_counter = 0;
+    for (size_t counter = 0; counter < count; counter++) {
+        error_counter |= first[counter] ^ second[counter];
+    }
+    return error_counter;
+}