diff --git a/networking/tls_sp_c32.c b/networking/tls_sp_c32.c index 87d44d5e0..d3bb36a39 100644 --- a/networking/tls_sp_c32.c +++ b/networking/tls_sp_c32.c @@ -788,29 +788,25 @@ static void sp_256_proj_point_add_10(sp_point* r, sp_point* p, sp_point* q, * r Resulting point. * g Point to multiply. * k Scalar to multiply by. + * map Indicates whether to convert result to affine. */ static void sp_256_ecc_mulmod_10(sp_point* r, const sp_point* g, const sp_digit* k /*, int map*/) { enum { map = 1 }; /* we always convert result to affine coordinates */ - sp_point td[3]; - sp_point* t[3]; + sp_point t[3]; sp_digit tmp[2 * 10 * 5]; sp_digit n; int i; int c, y; - memset(td, 0, sizeof(td)); - - t[0] = &td[0]; - t[1] = &td[1]; - t[2] = &td[2]; + memset(t, 0, sizeof(t)); /* t[0] = {0, 0, 1} * norm */ - t[0]->infinity = 1; + t[0].infinity = 1; /* t[1] = {g->x, g->y, g->z} * norm */ - sp_256_mod_mul_norm_10(t[1]->x, g->x); - sp_256_mod_mul_norm_10(t[1]->y, g->y); - sp_256_mod_mul_norm_10(t[1]->z, g->z); + sp_256_mod_mul_norm_10(t[1].x, g->x); + sp_256_mod_mul_norm_10(t[1].y, g->y); + sp_256_mod_mul_norm_10(t[1].z, g->z); i = 9; c = 22; @@ -827,19 +823,21 @@ static void sp_256_ecc_mulmod_10(sp_point* r, const sp_point* g, const sp_digit* y = (n >> 25) & 1; n <<= 1; - sp_256_proj_point_add_10(t[y^1], t[0], t[1], tmp); - memcpy(t[2], t[y], sizeof(sp_point)); - sp_256_proj_point_dbl_10(t[2], t[2], tmp); - memcpy(t[y], t[2], sizeof(sp_point)); +//FIXME: what's "tmp" and why do we pass it down? +//is it scratch space for "sensitive" data, to be memset(0) after we are done? + sp_256_proj_point_add_10(&t[y^1], &t[0], &t[1], tmp); + memcpy(&t[2], &t[y], sizeof(sp_point)); + sp_256_proj_point_dbl_10(&t[2], &t[2], tmp); + memcpy(&t[y], &t[2], sizeof(sp_point)); } if (map) - sp_256_map_10(r, t[0], tmp); + sp_256_map_10(r, &t[0], tmp); else - memcpy(r, t[0], sizeof(sp_point)); + memcpy(r, &t[0], sizeof(sp_point)); memset(tmp, 0, sizeof(tmp)); //paranoia - memset(td, 0, sizeof(td)); //paranoia + memset(t, 0, sizeof(t)); //paranoia } /* Multiply the base point of P256 by the scalar and return the result. @@ -847,6 +845,7 @@ static void sp_256_ecc_mulmod_10(sp_point* r, const sp_point* g, const sp_digit* * * r Resulting point. * k Scalar to multiply by. + * map Indicates whether to convert result to affine. */ static void sp_256_ecc_mulmod_base_10(sp_point* r, sp_digit* k /*, int map*/) {