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/*
* Utilities for constant-time cryptography.
*
* Author: Emilia Kasper (emilia@openssl.org)
* Based on previous work by Bodo Moeller, Emilia Kasper, Adam Langley
* (Google).
* ====================================================================
* Copyright (c) 2014 The OpenSSL Project. 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 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include "internal.h"
int bssl_constant_time_test_main(void);
static int test_binary_op_w(crypto_word (*op)(crypto_word a, crypto_word b),
crypto_word a, crypto_word b, int is_true) {
crypto_word c = op(a, b);
if (is_true && c != CONSTTIME_TRUE_W) {
return 1;
} else if (!is_true && c != CONSTTIME_FALSE_W) {
return 1;
}
return 0;
}
static int test_is_zero_w(crypto_word a) {
crypto_word c = constant_time_is_zero_w(a);
if (a == 0 && c != CONSTTIME_TRUE_W) {
return 1;
} else if (a != 0 && c != CONSTTIME_FALSE_W) {
return 1;
}
c = constant_time_is_nonzero_w(a);
if (a == 0 && c != CONSTTIME_FALSE_W) {
return 1;
} else if (a != 0 && c != CONSTTIME_TRUE_W) {
return 1;
}
return 0;
}
static int test_select_w(crypto_word a, crypto_word b) {
crypto_word selected = constant_time_select_w(CONSTTIME_TRUE_W, a, b);
if (selected != a) {
return 1;
}
selected = constant_time_select_w(CONSTTIME_FALSE_W, a, b);
if (selected != b) {
return 1;
}
return 0;
}
static crypto_word test_values_s[] = {
0,
1,
1024,
12345,
32000,
#if defined(OPENSSL_64_BIT)
0xffffffff / 2 - 1,
0xffffffff / 2,
0xffffffff / 2 + 1,
0xffffffff - 1,
0xffffffff,
#endif
SIZE_MAX / 2 - 1,
SIZE_MAX / 2,
SIZE_MAX / 2 + 1,
SIZE_MAX - 1,
SIZE_MAX
};
int bssl_constant_time_test_main(void) {
int num_failed = 0;
for (size_t i = 0;
i < sizeof(test_values_s) / sizeof(test_values_s[0]); ++i) {
crypto_word a = test_values_s[i];
num_failed += test_is_zero_w(a);
for (size_t j = 0;
j < sizeof(test_values_s) / sizeof(test_values_s[0]); ++j) {
crypto_word b = test_values_s[j];
num_failed += test_binary_op_w(&constant_time_eq_w, a, b, a == b);
num_failed += test_binary_op_w(&constant_time_eq_w, b, a, b == a);
num_failed += test_select_w(a, b);
}
}
return num_failed == 0;
}