56a10f97ba
A null pointer dereference, or null pointer plus small offset, is a clean runtime error in most environments. So it's not particularly useful to protect against this. While at it make a null pointer check that is actually necessary more robust. Signed-off-by: Janos Follath <janos.follath@arm.com>
152 lines
3.6 KiB
C
152 lines
3.6 KiB
C
/**
|
|
* 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.
|
|
*/
|
|
|
|
#include "common.h"
|
|
|
|
#if defined(MBEDTLS_BIGNUM_C)
|
|
|
|
#include <string.h>
|
|
|
|
#include "mbedtls/platform_util.h"
|
|
#include "mbedtls/error.h"
|
|
#include "mbedtls/bignum.h"
|
|
|
|
#if defined(MBEDTLS_PLATFORM_C)
|
|
#include "mbedtls/platform.h"
|
|
#else
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#define mbedtls_printf printf
|
|
#define mbedtls_calloc calloc
|
|
#define mbedtls_free free
|
|
#endif
|
|
|
|
#include "bignum_core.h"
|
|
#include "bignum_mod.h"
|
|
#include "bignum_mod_raw.h"
|
|
#include "constant_time_internal.h"
|
|
|
|
int mbedtls_mpi_mod_residue_setup( mbedtls_mpi_mod_residue *r,
|
|
mbedtls_mpi_mod_modulus *m,
|
|
mbedtls_mpi_uint *p,
|
|
size_t pn )
|
|
{
|
|
if( pn < m->n || !mbedtls_mpi_core_lt_ct( m->p, p, pn ) )
|
|
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
|
|
|
|
r->n = m->n;
|
|
r->p = p;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
void mbedtls_mpi_mod_residue_release( mbedtls_mpi_mod_residue *r )
|
|
{
|
|
if ( r == NULL )
|
|
return;
|
|
|
|
r->n = 0;
|
|
r->p = NULL;
|
|
}
|
|
|
|
void mbedtls_mpi_mod_modulus_init( mbedtls_mpi_mod_modulus *m )
|
|
{
|
|
if ( m == NULL )
|
|
return;
|
|
|
|
m->p = NULL;
|
|
m->n = 0;
|
|
m->plen = 0;
|
|
m->ext_rep = MBEDTLS_MPI_MOD_EXT_REP_INVALID;
|
|
m->int_rep = MBEDTLS_MPI_MOD_REP_INVALID;
|
|
}
|
|
|
|
void mbedtls_mpi_mod_modulus_free( mbedtls_mpi_mod_modulus *m )
|
|
{
|
|
if ( m == NULL )
|
|
return;
|
|
|
|
switch( m->int_rep )
|
|
{
|
|
case MBEDTLS_MPI_MOD_REP_MONTGOMERY:
|
|
mbedtls_free( m->rep.mont );
|
|
break;
|
|
case MBEDTLS_MPI_MOD_REP_OPT_RED:
|
|
mbedtls_free( m->rep.ored );
|
|
break;
|
|
case MBEDTLS_MPI_MOD_REP_INVALID:
|
|
break;
|
|
}
|
|
|
|
m->p = NULL;
|
|
m->n = 0;
|
|
m->plen = 0;
|
|
m->ext_rep = MBEDTLS_MPI_MOD_EXT_REP_INVALID;
|
|
m->int_rep = MBEDTLS_MPI_MOD_REP_INVALID;
|
|
}
|
|
|
|
int mbedtls_mpi_mod_modulus_setup( mbedtls_mpi_mod_modulus *m,
|
|
mbedtls_mpi_uint *p,
|
|
size_t pn,
|
|
mbedtls_mpi_mod_ext_rep ext_rep,
|
|
mbedtls_mpi_mod_rep_selector int_rep )
|
|
{
|
|
int ret = 0;
|
|
|
|
m->p = p;
|
|
m->n = pn;
|
|
m->plen = mbedtls_mpi_core_bitlen( p, pn );
|
|
|
|
switch( ext_rep )
|
|
{
|
|
case MBEDTLS_MPI_MOD_EXT_REP_LE:
|
|
case MBEDTLS_MPI_MOD_EXT_REP_BE:
|
|
m->ext_rep = ext_rep;
|
|
break;
|
|
default:
|
|
ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
|
|
goto exit;
|
|
}
|
|
|
|
switch( int_rep )
|
|
{
|
|
case MBEDTLS_MPI_MOD_REP_MONTGOMERY:
|
|
m->int_rep = int_rep;
|
|
m->rep.mont = NULL;
|
|
break;
|
|
case MBEDTLS_MPI_MOD_REP_OPT_RED:
|
|
m->int_rep = int_rep;
|
|
m->rep.ored = NULL;
|
|
break;
|
|
default:
|
|
ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
|
|
goto exit;
|
|
}
|
|
|
|
exit:
|
|
|
|
if( ret != 0 )
|
|
{
|
|
mbedtls_mpi_mod_modulus_free( m );
|
|
}
|
|
|
|
return( ret );
|
|
}
|
|
|
|
#endif /* MBEDTLS_BIGNUM_C */
|