Initial commit with upstream sources

Change-Id: Ie9460111f21fc955102fd8732a0173b2d0499a4a

1 files changed, 47 insertions, 0 deletions

diff --git a/lib/libutils/ext/buf_compare_ct.c b/lib/libutils/ext/buf_compare_ct.c
new file mode 100644
index 0000000..308435d
--- /dev/null
+++ b/lib/libutils/ext/buf_compare_ct.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2014, Linaro Limited
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <string_ext.h>
+
+int buf_compare_ct(const void *s1, const void *s2, size_t n)
+{
+	int res = 0;
+	unsigned char *c1 = (unsigned char *)s1;
+	unsigned char *c2 = (unsigned char *)s2;
+
+	while (n--) {
+		res |= (*c1 ^ *c2);
+		c1++;
+		c2++;
+	}
+
+	res |= res >> 4;
+	res |= res >> 2;
+	res |= res >> 1;
+	res &= 1;
+
+	return res;
+}