diff options
Diffstat (limited to 'src/ltm/bn_mp_montgomery_calc_normalization.c')
| -rw-r--r-- | src/ltm/bn_mp_montgomery_calc_normalization.c | 38 |
1 files changed, 25 insertions, 13 deletions
diff --git a/src/ltm/bn_mp_montgomery_calc_normalization.c b/src/ltm/bn_mp_montgomery_calc_normalization.c index 83797892..848378c4 100644 --- a/src/ltm/bn_mp_montgomery_calc_normalization.c +++ b/src/ltm/bn_mp_montgomery_calc_normalization.c @@ -1,7 +1,16 @@ #include "tommath_private.h" #ifdef BN_MP_MONTGOMERY_CALC_NORMALIZATION_C -/* LibTomMath, multiple-precision integer library -- Tom St Denis */ -/* SPDX-License-Identifier: Unlicense */ +/* 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. + * + * SPDX-License-Identifier: Unlicense + */ /* * shifts with subtractions when the result is greater than b. @@ -9,17 +18,16 @@ * The method is slightly modified to shift B unconditionally upto just under * the leading bit of b. This saves alot of multiple precision shifting. */ -mp_err mp_montgomery_calc_normalization(mp_int *a, const mp_int *b) +int mp_montgomery_calc_normalization(mp_int *a, const mp_int *b) { - int x, bits; - mp_err err; + int x, bits, res; /* how many bits of last digit does b use */ - bits = mp_count_bits(b) % MP_DIGIT_BIT; + bits = mp_count_bits(b) % DIGIT_BIT; if (b->used > 1) { - if ((err = mp_2expt(a, ((b->used - 1) * MP_DIGIT_BIT) + bits - 1)) != MP_OKAY) { - return err; + if ((res = mp_2expt(a, ((b->used - 1) * DIGIT_BIT) + bits - 1)) != MP_OKAY) { + return res; } } else { mp_set(a, 1uL); @@ -28,13 +36,13 @@ mp_err mp_montgomery_calc_normalization(mp_int *a, const mp_int *b) /* 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; + 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 ((err = s_mp_sub(a, b, a)) != MP_OKAY) { - return err; + if ((res = s_mp_sub(a, b, a)) != MP_OKAY) { + return res; } } } @@ -42,3 +50,7 @@ mp_err mp_montgomery_calc_normalization(mp_int *a, const mp_int *b) return MP_OKAY; } #endif + +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */ |