yuzu-emu/mbedtls
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Add coordinate randomization back

Browse source
This commit is contained in:
Manuel Pégourié-Gonnard 2013-11-20 20:07:26 +01:00
parent c30200e4ce
commit 70c14372c6
1 changed files with 8 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
library/ecp.c
View file

@ -1668,8 +1668,10 @@ cleanup:
* This part is actually common with the basic comb method (GECC 3.44)
*/
static int ecp_mul_comb_core( const ecp_group *grp, ecp_point *R,
const ecp_point T[], const unsigned char x[],
size_t d )
const ecp_point T[],
const unsigned char x[], size_t d,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
int ret;
ecp_point Txi;
@ -1677,9 +1679,11 @@ static int ecp_mul_comb_core( const ecp_group *grp, ecp_point *R,
ecp_point_init( &Txi );
/* Avoid useless doubling/addition of 0 by better initialisation */
/* Start with a non-zero point and randomize its coordinates */
i = d;
MPI_CHK( ecp_select_comb( grp, R, T, x[i] ) );
if( f_rng != 0 )
MPI_CHK( ecp_randomize_coordinates( grp, R, f_rng, p_rng ) );
while( i-- != 0 )
{
@ -1708,9 +1712,6 @@ int ecp_mul_comb( ecp_group *grp, ecp_point *R,
ecp_point Q, *T = NULL, S[2];
mpi M;
(void) f_rng;
(void) p_rng; // TODO
if( mpi_cmp_int( m, 0 ) < 0 || mpi_msb( m ) > grp->nbits )
return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
@ -1781,7 +1782,7 @@ int ecp_mul_comb( ecp_group *grp, ecp_point *R,
* Go for comb multiplication, Q = M * P
*/
ecp_comb_fixed( k, d, w, &M );
ecp_mul_comb_core( grp, &Q, T, k, d );
ecp_mul_comb_core( grp, &Q, T, k, d, f_rng, p_rng );
/*
* Now get m * P from M * P