First commit

Signed-off-by: Mattias Andrée <m@maandree.se>

1 files changed, 77 insertions, 0 deletions

diff --git a/librecrypt_equal_binary.c b/librecrypt_equal_binary.c
new file mode 100644
index 0000000..e1d17cd
--- /dev/null
+++ b/librecrypt_equal_binary.c
@@ -0,0 +1,77 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+#if defined(__GNUC__)
+# pragma GCC diagnostic ignored "-Wsuggest-attribute=const"
+# pragma GCC diagnostic ignored "-Wsuggest-attribute=pure"
+#endif
+
+
+static void
+explicit(unsigned char r)
+{
+	(void) r;
+#if defined(__GNUC__)
+	__asm__ volatile ("" :: "g" (r) : "memory");
+#endif
+}
+
+
+void (*volatile librecrypt_explicit_____)(unsigned char) = &explicit;
+
+
+int
+librecrypt_equal_binary(const void *a, const void *b, size_t len)
+{
+	const unsigned char *x = a;
+	const unsigned char *y = b;
+	size_t i;
+	unsigned char r = 0u;
+
+	for (i = 0u; i < len; i++)
+		r = (unsigned char)(r | (*x++ ^ *y++));
+
+	(*librecrypt_explicit_____)(r);
+
+	return r ? 0 : 1;
+}
+
+
+#else
+
+
+int
+main(void)
+{
+	SET_UP_ALARM();
+	EXPECT(librecrypt_equal_binary("", "", 0u) == 1);
+	EXPECT(librecrypt_equal_binary("", "", 1u) == 1);
+	EXPECT(librecrypt_equal_binary("a", "", 1u) == 0);
+	EXPECT(librecrypt_equal_binary("", "a", 1u) == 0);
+	EXPECT(librecrypt_equal_binary("a", "a", 1u) == 1);
+	EXPECT(librecrypt_equal_binary("a", "a", 2u) == 1);
+	EXPECT(librecrypt_equal_binary("abcdef", "abcdef", 6u) == 1);
+	EXPECT(librecrypt_equal_binary("abcdef", "Abcdef", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "AbCdef", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "abCdef", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "abCdeF", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "abcdeF", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "xbcdef", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "xbxdef", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "abxdef", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "abxdex", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "abcdex", 6u) == 0);
+	EXPECT(librecrypt_equal_binary("abcdef", "abcdex", 5u) == 1);
+	EXPECT(librecrypt_equal_binary("abcdef", "abcdex", 4u) == 1);
+	EXPECT(librecrypt_equal_binary("abcdef", "abcdex", 3u) == 1);
+	EXPECT(librecrypt_equal_binary("abcdef", "abcdex", 2u) == 1);
+	EXPECT(librecrypt_equal_binary("abcdef", "abcdex", 1u) == 1);
+	EXPECT(librecrypt_equal_binary("abcdef", "abcdex", 0u) == 1);
+	EXPECT(librecrypt_equal_binary(NULL, NULL, 0u) == 1);
+	return 0;
+}
+
+
+#endif