1 /* 2 * Utilities for constant-time cryptography. 3 * 4 * Author: Emilia Kasper (emilia (at) 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 (at) 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 (at) 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 <gtest/gtest.h> 53 54 55 static const unsigned CONSTTIME_TRUE = (unsigned)(~0); 56 static const unsigned CONSTTIME_FALSE = 0; 57 static const uint8_t CONSTTIME_TRUE_8 = 0xff; 58 static const uint8_t CONSTTIME_FALSE_8 = 0; 59 60 static unsigned FromBool(bool b) { 61 return b ? CONSTTIME_TRUE : CONSTTIME_FALSE; 62 } 63 64 static uint8_t FromBool8(bool b) { 65 return b ? CONSTTIME_TRUE_8 : CONSTTIME_FALSE_8; 66 } 67 68 static unsigned test_values[] = { 69 0, 70 1, 71 1024, 72 12345, 73 32000, 74 UINT_MAX / 2 - 1, 75 UINT_MAX / 2, 76 UINT_MAX / 2 + 1, 77 UINT_MAX - 1, 78 UINT_MAX, 79 }; 80 81 static uint8_t test_values_8[] = {0, 1, 2, 20, 32, 127, 128, 129, 255}; 82 83 static int signed_test_values[] = { 84 0, 1, -1, 1024, -1024, 12345, -12345, 85 32000, -32000, INT_MAX, INT_MIN, INT_MAX - 1, INT_MIN + 1}; 86 87 TEST(ConstantTimeTest, Test) { 88 for (unsigned a : test_values) { 89 SCOPED_TRACE(a); 90 91 EXPECT_EQ(FromBool(a == 0), constant_time_is_zero(a)); 92 EXPECT_EQ(FromBool8(a == 0), constant_time_is_zero_8(a)); 93 94 for (unsigned b : test_values) { 95 SCOPED_TRACE(b); 96 97 EXPECT_EQ(FromBool(a < b), constant_time_lt(a, b)); 98 EXPECT_EQ(FromBool8(a < b), constant_time_lt_8(a, b)); 99 100 EXPECT_EQ(FromBool(a >= b), constant_time_ge(a, b)); 101 EXPECT_EQ(FromBool8(a >= b), constant_time_ge_8(a, b)); 102 103 EXPECT_EQ(FromBool(a == b), constant_time_eq(a, b)); 104 EXPECT_EQ(FromBool8(a == b), constant_time_eq_8(a, b)); 105 106 EXPECT_EQ(a, constant_time_select(CONSTTIME_TRUE, a, b)); 107 EXPECT_EQ(b, constant_time_select(CONSTTIME_FALSE, a, b)); 108 } 109 } 110 111 for (int a : signed_test_values) { 112 SCOPED_TRACE(a); 113 for (int b : signed_test_values) { 114 SCOPED_TRACE(b); 115 116 EXPECT_EQ(a, constant_time_select_int(CONSTTIME_TRUE, a, b)); 117 EXPECT_EQ(b, constant_time_select_int(CONSTTIME_FALSE, a, b)); 118 119 EXPECT_EQ(FromBool(a == b), constant_time_eq_int(a, b)); 120 EXPECT_EQ(FromBool8(a == b), constant_time_eq_int_8(a, b)); 121 } 122 } 123 124 for (uint8_t a : test_values_8) { 125 SCOPED_TRACE(static_cast<int>(a)); 126 for (uint8_t b : test_values_8) { 127 SCOPED_TRACE(static_cast<int>(b)); 128 EXPECT_EQ(a, constant_time_select_8(CONSTTIME_TRUE_8, a, b)); 129 EXPECT_EQ(b, constant_time_select_8(CONSTTIME_FALSE_8, a, b)); 130 } 131 } 132 } 133
