CVSROOT: /cvs
Module name: src
Changes by: [email protected] 2024/11/22 07:59:40
Modified files:
lib/libcrypto/ec: ec_mult.c
Log message:
Split two helpers out of ec_wNAF_mul()
As its name indicates, the first, ec_compute_odd_multiples(), fills
point, 3 * point, 5 * point, ..., (2 * len - 1) * point into row[].
In fact, it first computes doubled = 2 * point and then goes on to
set row[i] = row[i - 1] + doubled. That's straightforward enough. One
change here is that this helper allocates row[i] on the fly rather
than preallocating the entire array of points up front.
The second piece is the actual precomputation, ec_wNAF_precompute().
It first computes the wNAF digits of the two scalars n and m (in this
order for now) with appropriate window size and length. Then the above
mentioned val[] array is allocated and populated with odd multiples
of point and generator. Finally, all points in val[] are made affine
in a single step, which means we only need one modular inversion, and
this then allows us to take fast paths in all the computations in the
one remaining loop in ec_wNAF_mul().
ok jsing
