1/**
2 * \file constant_time_invasive.h
3 *
4 * \brief Constant-time module: interfaces for invasive testing only.
5 *
6 * The interfaces in this file are intended for testing purposes only.
7 * They SHOULD NOT be made available in library integrations except when
8 * building the library for testing.
9 */
10/*
11 *  Copyright The Mbed TLS Contributors
12 *  SPDX-License-Identifier: Apache-2.0
13 *
14 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
15 *  not use this file except in compliance with the License.
16 *  You may obtain a copy of the License at
17 *
18 *  http://www.apache.org/licenses/LICENSE-2.0
19 *
20 *  Unless required by applicable law or agreed to in writing, software
21 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
22 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
23 *  See the License for the specific language governing permissions and
24 *  limitations under the License.
25 */
26
27#ifndef MBEDTLS_CONSTANT_TIME_INVASIVE_H
28#define MBEDTLS_CONSTANT_TIME_INVASIVE_H
29
30#include "common.h"
31
32#if defined(MBEDTLS_TEST_HOOKS)
33
34/** Turn a value into a mask:
35 * - if \p low <= \p c <= \p high,
36 *   return the all-bits 1 mask, aka (unsigned) -1
37 * - otherwise, return the all-bits 0 mask, aka 0
38 *
39 * \param low   The value to analyze.
40 * \param high  The value to analyze.
41 * \param c     The value to analyze.
42 *
43 * \return      All-bits-one if \p low <= \p c <= \p high, otherwise zero.
44 */
45unsigned char mbedtls_ct_uchar_mask_of_range(unsigned char low,
46                                             unsigned char high,
47                                             unsigned char c);
48
49#endif /* MBEDTLS_TEST_HOOKS */
50
51#endif /* MBEDTLS_CONSTANT_TIME_INVASIVE_H */
52