diff options
Diffstat (limited to 'libtommath/bn_mp_mod_2d.c')
| -rw-r--r-- | libtommath/bn_mp_mod_2d.c | 41 |
1 files changed, 14 insertions, 27 deletions
diff --git a/libtommath/bn_mp_mod_2d.c b/libtommath/bn_mp_mod_2d.c index 10d219d..5bf57a1 100644 --- a/libtommath/bn_mp_mod_2d.c +++ b/libtommath/bn_mp_mod_2d.c @@ -1,21 +1,13 @@ #include "tommath_private.h" #ifdef BN_MP_MOD_2D_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. - * - * SPDX-License-Identifier: Unlicense - */ +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ /* calc a value mod 2**b */ -int mp_mod_2d(const mp_int *a, int b, mp_int *c) +mp_err mp_mod_2d(const mp_int *a, int b, mp_int *c) { - int x, res; + int x; + mp_err err; /* if b is <= 0 then zero the int */ if (b <= 0) { @@ -24,28 +16,23 @@ int mp_mod_2d(const mp_int *a, int b, mp_int *c) } /* if the modulus is larger than the value than return */ - if (b >= (a->used * DIGIT_BIT)) { - res = mp_copy(a, c); - return res; + if (b >= (a->used * MP_DIGIT_BIT)) { + return mp_copy(a, c); } /* copy */ - if ((res = mp_copy(a, c)) != MP_OKAY) { - return res; + if ((err = mp_copy(a, c)) != MP_OKAY) { + return err; } /* zero digits above the last digit of the modulus */ - for (x = (b / DIGIT_BIT) + (((b % DIGIT_BIT) == 0) ? 0 : 1); x < c->used; x++) { - c->dp[x] = 0; - } + x = (b / MP_DIGIT_BIT) + (((b % MP_DIGIT_BIT) == 0) ? 0 : 1); + MP_ZERO_DIGITS(c->dp + x, c->used - x); + /* clear the digit that is not completely outside/inside the modulus */ - c->dp[b / DIGIT_BIT] &= - ((mp_digit)1 << (mp_digit)(b % DIGIT_BIT)) - (mp_digit)1; + c->dp[b / MP_DIGIT_BIT] &= + ((mp_digit)1 << (mp_digit)(b % MP_DIGIT_BIT)) - (mp_digit)1; mp_clamp(c); return MP_OKAY; } #endif - -/* ref: HEAD -> master, tag: v1.1.0 */ -/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ -/* commit time: 2019-01-28 20:32:32 +0100 */ |