mbedtls_mpi_mod_write: prevent data corruption

The function wasn't converting back data to internal representation when
writing it out.

Signed-off-by: Janos Follath <janos.follath@arm.com>
This commit is contained in:
Janos Follath 2022-11-26 15:39:02 +00:00
parent d7bb35257b
commit 8dfc8c41b7
2 changed files with 24 additions and 2 deletions

View file

@ -231,6 +231,7 @@ int mbedtls_mpi_mod_write( const mbedtls_mpi_mod_residue *r,
mbedtls_mpi_mod_ext_rep ext_rep )
{
int ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
int conv_ret = 0;
/* Do our best to check if r and m have been set up */
if ( r->limbs == 0 || m->limbs == 0 )
@ -238,12 +239,23 @@ int mbedtls_mpi_mod_write( const mbedtls_mpi_mod_residue *r,
if ( r->limbs != m->limbs )
goto cleanup;
if ( m->int_rep == MBEDTLS_MPI_MOD_REP_MONTGOMERY)
ret = mbedtls_mpi_mod_raw_from_mont_rep( r->p, m );
if ( m->int_rep == MBEDTLS_MPI_MOD_REP_MONTGOMERY )
{
conv_ret = mbedtls_mpi_mod_raw_from_mont_rep( r->p, m );
if( conv_ret != 0 )
goto cleanup;
}
ret = mbedtls_mpi_mod_raw_write( r->p, m, buf, buflen, ext_rep );
if ( m->int_rep == MBEDTLS_MPI_MOD_REP_MONTGOMERY )
conv_ret = mbedtls_mpi_mod_raw_to_mont_rep( r->p, m );
cleanup:
if ( ret == 0 )
ret = conv_ret;
return ( ret );
}
/* END MERGE SLOT 7 */