polarssl/include/mbedtls/constant_time.h
Dave Rodgman 0f2971a968 Update headers
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
2023-11-03 12:54:54 +00:00

34 lines
954 B
C

/**
* Constant-time functions
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
#ifndef MBEDTLS_CONSTANT_TIME_H
#define MBEDTLS_CONSTANT_TIME_H
#include <stddef.h>
/** Constant-time buffer comparison without branches.
*
* This is equivalent to the standard memcmp function, but is likely to be
* compiled to code using bitwise operation rather than a branch.
*
* This function can be used to write constant-time code by replacing branches
* with bit operations using masks.
*
* \param a Pointer to the first buffer.
* \param b Pointer to the second buffer.
* \param n The number of bytes to compare in the buffer.
*
* \return Zero if the content of the two buffer is the same,
* otherwise non-zero.
*/
int mbedtls_ct_memcmp(const void *a,
const void *b,
size_t n);
#endif /* MBEDTLS_CONSTANT_TIME_H */