mbedtls/tests/suites/test_suite_bignum_mod_raw.function

/* BEGIN_HEADER */
#include "mbedtls/bignum.h"
#include "mbedtls/entropy.h"
#include "bignum_core.h"
#include "bignum_mod_raw.h"
#include "constant_time_internal.h"
#include "test/constant_flow.h"

/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:MBEDTLS_BIGNUM_C
 * END_DEPENDENCIES
 */

/* BEGIN_CASE */
void mpi_mod_raw_io( data_t *input, int nb_int, int nx_32_int,
                     int iendian, int iret, int oret )
{
    mbedtls_mpi_mod_modulus m;
    mbedtls_mpi_mod_modulus_init( &m );

    if( iret != 0 )
        TEST_ASSERT( oret == 0 );

    TEST_LE_S( 0, nb_int );
    size_t nb = nb_int;

    unsigned char buf[1024];
    TEST_LE_U( nb, sizeof( buf ) );

    /* nx_32_int is the number of 32 bit limbs, if we have 64 bit limbs we need
     * to halve the number of limbs to have the same size. */
    size_t nx;
    TEST_LE_S( 0, nx_32_int );
    if( sizeof( mbedtls_mpi_uint ) == 8 )
        nx = nx_32_int / 2 + nx_32_int % 2;
    else
        nx = nx_32_int;

    mbedtls_mpi_uint X[sizeof( buf ) / sizeof( mbedtls_mpi_uint )];
    TEST_LE_U( nx, sizeof( X ) / sizeof( X[0] ) );

    int endian;
    if( iendian == MBEDTLS_MPI_MOD_EXT_REP_INVALID )
        endian = MBEDTLS_MPI_MOD_EXT_REP_LE;
    else
        endian = iendian;

    mbedtls_mpi_uint init[sizeof( X ) / sizeof( X[0] )];
    memset( init, 0xFF, sizeof( init ) );
    int ret = mbedtls_mpi_mod_modulus_setup( &m, init, nx, endian,
                                             MBEDTLS_MPI_MOD_REP_MONTGOMERY );
    TEST_EQUAL( ret, 0 );

    if( iendian == MBEDTLS_MPI_MOD_EXT_REP_INVALID && iret != 0 )
        m.ext_rep = MBEDTLS_MPI_MOD_EXT_REP_INVALID;

    ret = mbedtls_mpi_mod_raw_read( X, &m, input->x, input->len );
    TEST_EQUAL( ret, iret );

    if( iret == 0 )
    {
        if( iendian == MBEDTLS_MPI_MOD_EXT_REP_INVALID && oret != 0 )
            m.ext_rep = MBEDTLS_MPI_MOD_EXT_REP_INVALID;

        ret = mbedtls_mpi_mod_raw_write( X, &m, buf, nb );
        TEST_EQUAL( ret, oret );
    }

    if( ( iret == 0 ) && ( oret == 0 ) )
    {
        if( nb > input->len )
        {
            if( endian == MBEDTLS_MPI_MOD_EXT_REP_BE )
            {
                size_t leading_zeroes = nb - input->len;
                TEST_ASSERT( memcmp( buf + nb - input->len, input->x, input->len ) == 0 );
                for( size_t i = 0; i < leading_zeroes; i++ )
                    TEST_EQUAL( buf[i], 0 );
            }
            else
            {
                TEST_ASSERT( memcmp( buf, input->x, input->len ) == 0 );
                for( size_t i = input->len; i < nb; i++ )
                    TEST_EQUAL( buf[i], 0 );
            }
        }
        else
        {
            if( endian == MBEDTLS_MPI_MOD_EXT_REP_BE )
            {
                size_t leading_zeroes = input->len - nb;
                TEST_ASSERT( memcmp( input->x + input->len - nb, buf, nb ) == 0 );
                for( size_t i = 0; i < leading_zeroes; i++ )
                    TEST_EQUAL( input->x[i], 0 );
            }
            else
            {
                TEST_ASSERT( memcmp( input->x, buf, nb ) == 0 );
                for( size_t i = nb; i < input->len; i++ )
                    TEST_EQUAL( input->x[i], 0 );
            }
        }
    }

exit:
    mbedtls_mpi_mod_modulus_free( &m );
}
/* END_CASE */

/* BEGIN_CASE */
void mpi_mod_raw_cond_assign( data_t * input_X,
                              data_t * input_Y,
                              int input_bytes )
{
    mbedtls_mpi_uint *X = NULL;
    mbedtls_mpi_uint *Y = NULL;
    mbedtls_mpi_uint *buff_m = NULL;
    mbedtls_mpi_mod_modulus m;
    size_t limbs_X = CHARS_TO_LIMBS( input_X->len );
    size_t limbs_Y = CHARS_TO_LIMBS( input_Y->len );
    size_t limbs = limbs_X;
    size_t copy_limbs = CHARS_TO_LIMBS( input_bytes );
    size_t bytes = limbs * sizeof( mbedtls_mpi_uint );
    size_t copy_bytes = copy_limbs * sizeof( mbedtls_mpi_uint );

    mbedtls_mpi_mod_modulus_init( &m );

    TEST_EQUAL( limbs_X, limbs_Y );
    TEST_ASSERT( copy_limbs <= limbs );

    ASSERT_ALLOC( X, limbs );
    ASSERT_ALLOC( Y, limbs );

    ASSERT_ALLOC( buff_m, limbs );
    TEST_ASSERT( mbedtls_mpi_mod_modulus_setup(
                        &m, buff_m, copy_limbs,
                        MBEDTLS_MPI_MOD_EXT_REP_BE,
                        MBEDTLS_MPI_MOD_REP_MONTGOMERY )
                 == 0 );

    TEST_ASSERT( mbedtls_mpi_core_read_be( X, limbs,
                                           input_X->x, input_X->len )
                 == 0 );

    TEST_ASSERT( mbedtls_mpi_core_read_be( Y, limbs,
                                           input_Y->x, input_Y->len )
                 == 0 );

    /* condition is false */
    TEST_CF_SECRET( X, bytes );
    TEST_CF_SECRET( Y, bytes );

    mbedtls_mpi_mod_raw_cond_assign( X, Y, &m, 0 );

    TEST_CF_PUBLIC( X, bytes );
    TEST_CF_PUBLIC( Y, bytes );

    TEST_ASSERT( memcmp( X, Y, bytes ) != 0 );

    /* condition is true */
    TEST_CF_SECRET( X, bytes );
    TEST_CF_SECRET( Y, bytes );

    mbedtls_mpi_mod_raw_cond_assign( X, Y, &m, 1 );

    TEST_CF_PUBLIC( X, bytes );
    TEST_CF_PUBLIC( Y, bytes );

    /* Check if the given length is copied even it is smaller
       than the length of the given MPIs. */
    if( copy_limbs <limbs )
    {
        ASSERT_COMPARE( X, copy_bytes, Y, copy_bytes );
        TEST_ASSERT( memcmp( X, Y, bytes ) != 0 );
    }
    else
        ASSERT_COMPARE( X, bytes, Y, bytes );

exit:
    mbedtls_free( X );
    mbedtls_free( Y );

    mbedtls_mpi_mod_modulus_free( &m );
    mbedtls_free( buff_m );
}
/* END_CASE */

/* BEGIN_CASE */
void mpi_mod_raw_cond_swap( data_t * input_X,
                            data_t * input_Y,
                            int input_bytes )
{
    mbedtls_mpi_uint *tmp_X = NULL;
    mbedtls_mpi_uint *tmp_Y = NULL;
    mbedtls_mpi_uint *X = NULL;
    mbedtls_mpi_uint *Y = NULL;
    mbedtls_mpi_uint *buff_m = NULL;
    mbedtls_mpi_mod_modulus m;
    size_t limbs_X = CHARS_TO_LIMBS( input_X->len );
    size_t limbs_Y = CHARS_TO_LIMBS( input_Y->len );
    size_t limbs = limbs_X;
    size_t copy_limbs = CHARS_TO_LIMBS( input_bytes );
    size_t bytes = limbs * sizeof( mbedtls_mpi_uint );
    size_t copy_bytes = copy_limbs * sizeof( mbedtls_mpi_uint );

    mbedtls_mpi_mod_modulus_init( &m );

    TEST_EQUAL( limbs_X, limbs_Y );
    TEST_ASSERT( copy_limbs <= limbs );

    ASSERT_ALLOC( tmp_X, limbs );
    ASSERT_ALLOC( tmp_Y, limbs );

    ASSERT_ALLOC( buff_m, copy_limbs );
    TEST_ASSERT( mbedtls_mpi_mod_modulus_setup(
                        &m, buff_m, copy_limbs,
                        MBEDTLS_MPI_MOD_EXT_REP_BE,
                        MBEDTLS_MPI_MOD_REP_MONTGOMERY )
                 == 0 );

    TEST_ASSERT( mbedtls_mpi_core_read_be( tmp_X, limbs, input_X->x, input_X->len )
                 == 0 );
    ASSERT_ALLOC( X, limbs );
    memcpy( X, tmp_X, bytes );

    TEST_ASSERT( mbedtls_mpi_core_read_be( tmp_Y, limbs, input_Y->x, input_Y->len )
                 == 0 );
    ASSERT_ALLOC( Y, bytes );
    memcpy( Y, tmp_Y, bytes );

    /* condition is false */
    TEST_CF_SECRET( X, bytes );
    TEST_CF_SECRET( Y, bytes );

    mbedtls_mpi_mod_raw_cond_swap( X, Y, &m, 0 );

    TEST_CF_PUBLIC( X, bytes );
    TEST_CF_PUBLIC( Y, bytes );

    ASSERT_COMPARE( X, bytes, tmp_X, bytes );
    ASSERT_COMPARE( Y, bytes, tmp_Y, bytes );

    /* condition is true */
    TEST_CF_SECRET( X, bytes );
    TEST_CF_SECRET( Y, bytes );

    mbedtls_mpi_mod_raw_cond_swap( X, Y, &m, 1 );

    TEST_CF_PUBLIC( X, bytes );
    TEST_CF_PUBLIC( Y, bytes );

    /* Check if the given length is copied even it is smaller
       than the length of the given MPIs. */
    if( copy_limbs < limbs )
    {
        ASSERT_COMPARE( X, copy_bytes, tmp_Y, copy_bytes );
        ASSERT_COMPARE( Y, copy_bytes, tmp_X, copy_bytes );
        TEST_ASSERT( memcmp( X, tmp_X, bytes ) != 0 );
        TEST_ASSERT( memcmp( X, tmp_Y, bytes ) != 0 );
        TEST_ASSERT( memcmp( Y, tmp_X, bytes ) != 0 );
        TEST_ASSERT( memcmp( Y, tmp_Y, bytes ) != 0 );
    }
    else
    {
        ASSERT_COMPARE( X, bytes, tmp_Y, bytes );
        ASSERT_COMPARE( Y, bytes, tmp_X, bytes );
    }

exit:
    mbedtls_free( tmp_X );
    mbedtls_free( tmp_Y );
    mbedtls_free( X );
    mbedtls_free( Y );

    mbedtls_mpi_mod_modulus_free( &m );
    mbedtls_free( buff_m );
}
/* END_CASE */