mbedtls/library/constant_time_invasive.h
Gabor Mezei 3a755f511f
Add documentation for the functions
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-12-08 16:24:22 +01:00

52 lines
1.7 KiB
C

/**
* \file constant_time_invasive.h
*
* \brief Constant-time module: interfaces for invasive testing only.
*
* The interfaces in this file are intended for testing purposes only.
* They SHOULD NOT be made available in library integrations except when
* building the library for testing.
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef MBEDTLS_CONSTANT_TIME_INVASIVE_H
#define MBEDTLS_CONSTANT_TIME_INVASIVE_H
#include "common.h"
#if defined(MBEDTLS_TEST_HOOKS)
/** Turn a value into a mask:
* - if \p low <= \p c <= \p high,
* return the all-bits 1 mask, aka (unsigned) -1
* - otherwise, return the all-bits 0 mask, aka 0
*
* \param low The value to analyze.
* \param high The value to analyze.
* \param c The value to analyze.
*
* \return All-bits-one if \p low <= \p c <= \p high, otherwise zero.
*/
unsigned char mbedtls_ct_uchar_mask_of_range( unsigned char low,
unsigned char high,
unsigned char c );
#endif /* MBEDTLS_TEST_HOOKS */
#endif /* MBEDTLS_CONSTANT_TIME_INVASIVE_H */