library/bignum_core.h

/**
 *  Internal bignum functions
 *
 *  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_BIGNUM_CORE_H
#define MBEDTLS_BIGNUM_CORE_H

#include "common.h"

#if defined(MBEDTLS_BIGNUM_C)
#include "mbedtls/bignum.h"
#endif

#define MPI_VALIDATE_RET( cond )                                       \
    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_MPI_BAD_INPUT_DATA )
#define MPI_VALIDATE( cond )                                           \
    MBEDTLS_INTERNAL_VALIDATE( cond )

#define ciL    (sizeof(mbedtls_mpi_uint))   /* chars in limb  */
#define biL    (ciL << 3)                   /* bits  in limb  */
#define biH    (ciL << 2)                   /* half limb size */

/*
 * Convert between bits/chars and number of limbs
 * Divide first in order to avoid potential overflows
 */
#define BITS_TO_LIMBS(i)  ( (i) / biL + ( (i) % biL != 0 ) )
#define CHARS_TO_LIMBS(i) ( (i) / ciL + ( (i) % ciL != 0 ) )

size_t mbedtls_mpi_core_clz( const mbedtls_mpi_uint x );

size_t mbedtls_mpi_core_bitlen( const mbedtls_mpi_uint *X, size_t nx );

void mbedtls_mpi_core_bigendian_to_host( mbedtls_mpi_uint * const X,
                                         size_t limbs );

int mbedtls_mpi_core_read_le( mbedtls_mpi_uint *X,
                              size_t nx,
                              const unsigned char *buf,
                              size_t buflen );

int mbedtls_mpi_core_read_be( mbedtls_mpi_uint *X,
                              size_t nx,
                              const unsigned char *buf,
                              size_t buflen );

int mbedtls_mpi_core_write_le( const mbedtls_mpi_uint *X,
                               size_t nx,
                               unsigned char *buf,
                               size_t buflen );

int mbedtls_mpi_core_write_be( const mbedtls_mpi_uint *X,
                               size_t nx,
                               unsigned char *buf,
                               size_t buflen );

#endif /* MBEDTLS_BIGNUM_CORE_H */