diff options
Diffstat (limited to 'libtommath/bn_mp_montgomery_calc_normalization.c')
| -rw-r--r-- | libtommath/bn_mp_montgomery_calc_normalization.c | 69 |
1 files changed, 27 insertions, 42 deletions
diff --git a/libtommath/bn_mp_montgomery_calc_normalization.c b/libtommath/bn_mp_montgomery_calc_normalization.c index 679a871..8379789 100644 --- a/libtommath/bn_mp_montgomery_calc_normalization.c +++ b/libtommath/bn_mp_montgomery_calc_normalization.c @@ -1,19 +1,7 @@ -#include <tommath_private.h> +#include "tommath_private.h" #ifdef BN_MP_MONTGOMERY_CALC_NORMALIZATION_C -/* LibTomMath, multiple-precision integer library -- Tom St Denis - * - * LibTomMath is a library that provides multiple-precision - * integer arithmetic as well as number theoretic functionality. - * - * The library was designed directly after the MPI library by - * Michael Fromberger but has been written from scratch with - * additional optimizations in place. - * - * The library is free for all purposes without any express - * guarantee it works. - * - * Tom St Denis, tstdenis82@gmail.com, http://libtom.org - */ +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ /* * shifts with subtractions when the result is greater than b. @@ -21,39 +9,36 @@ * The method is slightly modified to shift B unconditionally upto just under * the leading bit of b. This saves alot of multiple precision shifting. */ -int mp_montgomery_calc_normalization (mp_int * a, mp_int * b) +mp_err mp_montgomery_calc_normalization(mp_int *a, const mp_int *b) { - int x, bits, res; + int x, bits; + mp_err err; - /* how many bits of last digit does b use */ - bits = mp_count_bits (b) % DIGIT_BIT; + /* how many bits of last digit does b use */ + bits = mp_count_bits(b) % MP_DIGIT_BIT; - if (b->used > 1) { - if ((res = mp_2expt (a, ((b->used - 1) * DIGIT_BIT) + bits - 1)) != MP_OKAY) { - return res; - } - } else { - mp_set(a, 1); - bits = 1; - } + if (b->used > 1) { + if ((err = mp_2expt(a, ((b->used - 1) * MP_DIGIT_BIT) + bits - 1)) != MP_OKAY) { + return err; + } + } else { + mp_set(a, 1uL); + bits = 1; + } - /* now compute C = A * B mod b */ - for (x = bits - 1; x < (int)DIGIT_BIT; x++) { - if ((res = mp_mul_2 (a, a)) != MP_OKAY) { - return res; - } - if (mp_cmp_mag (a, b) != MP_LT) { - if ((res = s_mp_sub (a, b, a)) != MP_OKAY) { - return res; + /* now compute C = A * B mod b */ + for (x = bits - 1; x < (int)MP_DIGIT_BIT; x++) { + if ((err = mp_mul_2(a, a)) != MP_OKAY) { + return err; } - } - } + if (mp_cmp_mag(a, b) != MP_LT) { + if ((err = s_mp_sub(a, b, a)) != MP_OKAY) { + return err; + } + } + } - return MP_OKAY; + return MP_OKAY; } #endif - -/* ref: $Format:%D$ */ -/* git commit: $Format:%H$ */ -/* commit time: $Format:%ai$ */ |