Clarify initialization of T in mul_comb()
Exactly one of three ways will be used, so make that clear by using an
if 1 else if 2 else 3 structure.
While at it, don't initialize variables at declaration, just to make extra
sure they're properly initialized afterwards in all code paths.
@@ -1885,7 +1885,7 @@ static unsigned char ecp_pick_window_size( const mbedtls_ecp_group *grp,
*
* This function is mainly responsible for administrative work:
* - managing the restart context if enabled
- * - managing the table of precomputed points (passed between the above two
+ * - managing the table of precomputed points (passed between the below two
* functions): allocation, computation, ownership tranfer, freeing.
*
* It delegates the actual arithmetic work to:
@@ -1900,10 +1900,10 @@ static int ecp_mul_comb( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
mbedtls_ecp_restart_ctx *rs_ctx )
{
int ret;
- unsigned char w, p_eq_g = 0, i;
+ unsigned char w, p_eq_g, i;
size_t d;
- unsigned char T_size = 0, T_ok = 0;
- mbedtls_ecp_point *T = NULL;
+ unsigned char T_size, T_ok;
+ mbedtls_ecp_point *T;
ECP_RS_ENTER( rsm );
@@ -1925,23 +1925,21 @@ static int ecp_mul_comb( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
T = grp->T;
T_ok = 1;
}
-
+ else
#if defined(MBEDTLS_ECP_RESTARTABLE)
/* Pre-computed table: do we have one in progress? complete? */
- if( rs_ctx != NULL && rs_ctx->rsm != NULL && rs_ctx->rsm->T != NULL && T == NULL )
+ if( rs_ctx != NULL && rs_ctx->rsm != NULL && rs_ctx->rsm->T != NULL )
{
/* transfer ownership of T from rsm to local function */
T = rs_ctx->rsm->T;
rs_ctx->rsm->T = NULL;
rs_ctx->rsm->T_size = 0;
- if( rs_ctx->rsm->state >= ecp_rsm_comb_core )
- T_ok = 1;
+ T_ok = rs_ctx->rsm->state >= ecp_rsm_comb_core;
}
+ else
#endif
-
/* Allocate table if we didn't have any */
- if( T == NULL )
{
T = mbedtls_calloc( T_size, sizeof( mbedtls_ecp_point ) );
if( T == NULL )
@@ -1952,6 +1950,8 @@ static int ecp_mul_comb( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
for( i = 0; i < T_size; i++ )
mbedtls_ecp_point_init( &T[i] );
+
+ T_ok = 0;
}
/* Compute table (or finish computing it) if not done already */
