Security-57031.1.35.tar.gz

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

diff --git a/Security/utilities/src/comparison.c b/Security/utilities/src/comparison.c
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+/*
+ * Copyright (c) 2012,2014 Apple Inc. All Rights Reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+
+#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;
+}