172 lines
5.8 KiB
C++
172 lines
5.8 KiB
C++
/*
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* Utilities for constant-time cryptography.
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*
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* Author: Emilia Kasper (emilia@openssl.org)
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* Based on previous work by Bodo Moeller, Emilia Kasper, Adam Langley
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* (Google).
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* ====================================================================
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* Copyright (c) 2014 The OpenSSL Project. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* "This product includes cryptographic software written by
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* Eric Young (eay@cryptsoft.com)"
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* The word 'cryptographic' can be left out if the rouines from the library
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* being used are not cryptographic related :-).
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* 4. If you include any Windows specific code (or a derivative thereof) from
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* the apps directory (application code) you must include an acknowledgement:
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* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
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*
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* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* The licence and distribution terms for any publically available version or
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* derivative of this code cannot be changed. i.e. this code cannot simply be
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* copied and put under another distribution licence
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* [including the GNU Public Licence.]
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*/
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#include "internal.h"
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#include <limits.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <limits>
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#include <gtest/gtest.h>
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#include <openssl/mem.h>
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#include <openssl/rand.h>
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static uint8_t FromBool8(bool b) {
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return b ? CONSTTIME_TRUE_8 : CONSTTIME_FALSE_8;
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}
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static crypto_word_t FromBoolW(bool b) {
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return b ? CONSTTIME_TRUE_W : CONSTTIME_FALSE_W;
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}
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static const uint8_t test_values_8[] = {0, 1, 2, 20, 32, 127, 128, 129, 255};
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static crypto_word_t test_values_w[] = {
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0,
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1,
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1024,
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12345,
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32000,
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#if defined(OPENSSL_64_BIT)
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0xffffffff / 2 - 1,
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0xffffffff / 2,
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0xffffffff / 2 + 1,
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0xffffffff - 1,
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0xffffffff,
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#endif
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std::numeric_limits<crypto_word_t>::max() / 2 - 1,
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std::numeric_limits<crypto_word_t>::max() / 2,
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std::numeric_limits<crypto_word_t>::max() / 2 + 1,
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std::numeric_limits<crypto_word_t>::max() - 1,
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std::numeric_limits<crypto_word_t>::max(),
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};
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static int signed_test_values[] = {
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0, 1, -1, 1024, -1024, 12345, -12345,
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32000, -32000, INT_MAX, INT_MIN, INT_MAX - 1, INT_MIN + 1};
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TEST(ConstantTimeTest, Test) {
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for (crypto_word_t a : test_values_w) {
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SCOPED_TRACE(a);
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EXPECT_EQ(FromBoolW(a == 0), constant_time_is_zero_w(a));
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EXPECT_EQ(FromBool8(a == 0), constant_time_is_zero_8(a));
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for (crypto_word_t b : test_values_w) {
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SCOPED_TRACE(b);
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EXPECT_EQ(FromBoolW(a < b), constant_time_lt_w(a, b));
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EXPECT_EQ(FromBool8(a < b), constant_time_lt_8(a, b));
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EXPECT_EQ(FromBoolW(a >= b), constant_time_ge_w(a, b));
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EXPECT_EQ(FromBool8(a >= b), constant_time_ge_8(a, b));
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EXPECT_EQ(FromBoolW(a == b), constant_time_eq_w(a, b));
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EXPECT_EQ(FromBool8(a == b), constant_time_eq_8(a, b));
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EXPECT_EQ(a, constant_time_select_w(CONSTTIME_TRUE_W, a, b));
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EXPECT_EQ(b, constant_time_select_w(CONSTTIME_FALSE_W, a, b));
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}
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}
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for (int a : signed_test_values) {
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SCOPED_TRACE(a);
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for (int b : signed_test_values) {
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SCOPED_TRACE(b);
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EXPECT_EQ(a, constant_time_select_int(CONSTTIME_TRUE_W, a, b));
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EXPECT_EQ(b, constant_time_select_int(CONSTTIME_FALSE_W, a, b));
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EXPECT_EQ(FromBoolW(a == b), constant_time_eq_int(a, b));
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EXPECT_EQ(FromBool8(a == b), constant_time_eq_int_8(a, b));
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}
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}
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for (uint8_t a : test_values_8) {
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SCOPED_TRACE(static_cast<int>(a));
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for (uint8_t b : test_values_8) {
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SCOPED_TRACE(static_cast<int>(b));
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EXPECT_EQ(a, constant_time_select_8(CONSTTIME_TRUE_8, a, b));
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EXPECT_EQ(b, constant_time_select_8(CONSTTIME_FALSE_8, a, b));
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}
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}
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}
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TEST(ConstantTimeTest, MemCmp) {
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uint8_t buf[256], copy[256];
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RAND_bytes(buf, sizeof(buf));
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OPENSSL_memcpy(copy, buf, sizeof(buf));
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EXPECT_EQ(0, CRYPTO_memcmp(buf, copy, sizeof(buf)));
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for (size_t i = 0; i < sizeof(buf); i++) {
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for (uint8_t bit = 1; bit != 0; bit <<= 1) {
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OPENSSL_memcpy(copy, buf, sizeof(buf));
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copy[i] ^= bit;
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EXPECT_NE(0, CRYPTO_memcmp(buf, copy, sizeof(buf)));
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}
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}
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}
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TEST(ConstantTimeTest, ValueBarrier) {
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for (int i = 0; i < 10; i++) {
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crypto_word_t word;
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RAND_bytes(reinterpret_cast<uint8_t *>(&word), sizeof(word));
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EXPECT_EQ(word, value_barrier_w(word));
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uint32_t u32;
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RAND_bytes(reinterpret_cast<uint8_t *>(&u32), sizeof(u32));
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EXPECT_EQ(u32, value_barrier_u32(u32));
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uint64_t u64;
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RAND_bytes(reinterpret_cast<uint8_t *>(&u64), sizeof(u64));
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EXPECT_EQ(u64, value_barrier_u64(u64));
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}
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}
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