51 lines
2.2 KiB
C++
51 lines
2.2 KiB
C++
/**
|
|
* \file bignum_internal.h
|
|
*
|
|
* \brief Internal-only bignum public-key cryptosystem API.
|
|
*
|
|
* This file declares bignum-related functions that are to be used
|
|
* only from within the Mbed TLS library itself.
|
|
*
|
|
*/
|
|
/*
|
|
* Copyright The Mbed TLS Contributors
|
|
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
|
|
*/
|
|
#ifndef MBEDTLS_BIGNUM_INTERNAL_H
|
|
#define MBEDTLS_BIGNUM_INTERNAL_H
|
|
|
|
/**
|
|
* \brief Perform a modular exponentiation: X = A^E mod N
|
|
*
|
|
* \warning This function is not constant time with respect to \p E (the exponent).
|
|
*
|
|
* \param X The destination MPI. This must point to an initialized MPI.
|
|
* This must not alias E or N.
|
|
* \param A The base of the exponentiation.
|
|
* This must point to an initialized MPI.
|
|
* \param E The exponent MPI. This must point to an initialized MPI.
|
|
* \param N The base for the modular reduction. This must point to an
|
|
* initialized MPI.
|
|
* \param prec_RR A helper MPI depending solely on \p N which can be used to
|
|
* speed-up multiple modular exponentiations for the same value
|
|
* of \p N. This may be \c NULL. If it is not \c NULL, it must
|
|
* point to an initialized MPI. If it hasn't been used after
|
|
* the call to mbedtls_mpi_init(), this function will compute
|
|
* the helper value and store it in \p prec_RR for reuse on
|
|
* subsequent calls to this function. Otherwise, the function
|
|
* will assume that \p prec_RR holds the helper value set by a
|
|
* previous call to mbedtls_mpi_exp_mod(), and reuse it.
|
|
*
|
|
* \return \c 0 if successful.
|
|
* \return #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
|
|
* \return #MBEDTLS_ERR_MPI_BAD_INPUT_DATA if \c N is negative or
|
|
* even, or if \c E is negative.
|
|
* \return Another negative error code on different kinds of failures.
|
|
*
|
|
*/
|
|
int mbedtls_mpi_exp_mod_unsafe(mbedtls_mpi *X, const mbedtls_mpi *A,
|
|
const mbedtls_mpi *E, const mbedtls_mpi *N,
|
|
mbedtls_mpi *prec_RR);
|
|
|
|
#endif /* bignum_internal.h */
|