1 /*
2 * Utilities for constant-time cryptography.
3 *
4 * Author: Emilia Kasper (emilia@openssl.org)
5 * Based on previous work by Bodo Moeller, Emilia Kasper, Adam Langley
6 * (Google).
7 * ====================================================================
8 * Copyright (c) 2014 The OpenSSL Project. All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * "This product includes cryptographic software written by
21 * Eric Young (eay@cryptsoft.com)"
22 * The word 'cryptographic' can be left out if the rouines from the library
23 * being used are not cryptographic related :-).
24 * 4. If you include any Windows specific code (or a derivative thereof) from
25 * the apps directory (application code) you must include an acknowledgement:
26 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
27 *
28 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 *
40 * The licence and distribution terms for any publically available version or
41 * derivative of this code cannot be changed. i.e. this code cannot simply be
42 * copied and put under another distribution licence
43 * [including the GNU Public Licence.]
44 */
45
46 #include "internal.h"
47
48 #include <limits.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51
52 #include <limits>
53
54 #include <gtest/gtest.h>
55
56
FromBool8(bool b)57 static uint8_t FromBool8(bool b) {
58 return b ? CONSTTIME_TRUE_8 : CONSTTIME_FALSE_8;
59 }
60
FromBoolW(bool b)61 static crypto_word_t FromBoolW(bool b) {
62 return b ? CONSTTIME_TRUE_W : CONSTTIME_FALSE_W;
63 }
64
65 static const uint8_t test_values_8[] = {0, 1, 2, 20, 32, 127, 128, 129, 255};
66
67 static crypto_word_t test_values_w[] = {
68 0,
69 1,
70 1024,
71 12345,
72 32000,
73 #if defined(OPENSSL_64_BIT)
74 0xffffffff / 2 - 1,
75 0xffffffff / 2,
76 0xffffffff / 2 + 1,
77 0xffffffff - 1,
78 0xffffffff,
79 #endif
80 std::numeric_limits<crypto_word_t>::max() / 2 - 1,
81 std::numeric_limits<crypto_word_t>::max() / 2,
82 std::numeric_limits<crypto_word_t>::max() / 2 + 1,
83 std::numeric_limits<crypto_word_t>::max() - 1,
84 std::numeric_limits<crypto_word_t>::max(),
85 };
86
87 static int signed_test_values[] = {
88 0, 1, -1, 1024, -1024, 12345, -12345,
89 32000, -32000, INT_MAX, INT_MIN, INT_MAX - 1, INT_MIN + 1};
90
TEST(ConstantTimeTest,Test)91 TEST(ConstantTimeTest, Test) {
92 for (crypto_word_t a : test_values_w) {
93 SCOPED_TRACE(a);
94
95 EXPECT_EQ(FromBoolW(a == 0), constant_time_is_zero_w(a));
96 EXPECT_EQ(FromBool8(a == 0), constant_time_is_zero_8(a));
97
98 for (crypto_word_t b : test_values_w) {
99 SCOPED_TRACE(b);
100
101 EXPECT_EQ(FromBoolW(a < b), constant_time_lt_w(a, b));
102 EXPECT_EQ(FromBool8(a < b), constant_time_lt_8(a, b));
103
104 EXPECT_EQ(FromBoolW(a >= b), constant_time_ge_w(a, b));
105 EXPECT_EQ(FromBool8(a >= b), constant_time_ge_8(a, b));
106
107 EXPECT_EQ(FromBoolW(a == b), constant_time_eq_w(a, b));
108 EXPECT_EQ(FromBool8(a == b), constant_time_eq_8(a, b));
109
110 EXPECT_EQ(a, constant_time_select_w(CONSTTIME_TRUE_W, a, b));
111 EXPECT_EQ(b, constant_time_select_w(CONSTTIME_FALSE_W, a, b));
112 }
113 }
114
115 for (int a : signed_test_values) {
116 SCOPED_TRACE(a);
117 for (int b : signed_test_values) {
118 SCOPED_TRACE(b);
119
120 EXPECT_EQ(a, constant_time_select_int(CONSTTIME_TRUE_W, a, b));
121 EXPECT_EQ(b, constant_time_select_int(CONSTTIME_FALSE_W, a, b));
122
123 EXPECT_EQ(FromBoolW(a == b), constant_time_eq_int(a, b));
124 EXPECT_EQ(FromBool8(a == b), constant_time_eq_int_8(a, b));
125 }
126 }
127
128 for (uint8_t a : test_values_8) {
129 SCOPED_TRACE(static_cast<int>(a));
130 for (uint8_t b : test_values_8) {
131 SCOPED_TRACE(static_cast<int>(b));
132 EXPECT_EQ(a, constant_time_select_8(CONSTTIME_TRUE_8, a, b));
133 EXPECT_EQ(b, constant_time_select_8(CONSTTIME_FALSE_8, a, b));
134 }
135 }
136 }
137