From d77ab463184d113ca6119403887c9f4ed0dfdf0b Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Sun, 26 Apr 2026 22:36:47 +0200 Subject: First commit MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- librecrypt_equal_binary.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 librecrypt_equal_binary.c (limited to 'librecrypt_equal_binary.c') 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 -- cgit v1.2.3-70-g09d2