diff options
author | Steffen Jaeckel <s_jaeckel@gmx.de> | 2019-09-16 15:50:38 +0200 |
---|---|---|
committer | Matt Johnston <matt@ucc.asn.au> | 2019-09-16 21:50:38 +0800 |
commit | 615ed4e46a52b6bfe0bfc581b8c2fbcc6cc488d1 (patch) | |
tree | 12b2ba29ae4c42fc65d64d43968c5d03ab3f4452 /libtommath/bn_mp_div_3.c | |
parent | fa116e983b4931010e1082dd5c8bf38bbc77718c (diff) |
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
* make key-generation compliant to FIPS 186.4
* fix includes in tommath_class.h
* update fuzzcorpus instead of error-out
* fixup fuzzing make-targets
* update Makefile.in
* apply necessary patches to ltm sources
* clean-up not required ltm files
* update to vanilla ltm 1.1.0
this already only contains the required files
* remove set/get double
Diffstat (limited to 'libtommath/bn_mp_div_3.c')
-rw-r--r-- | libtommath/bn_mp_div_3.c | 100 |
1 files changed, 48 insertions, 52 deletions
diff --git a/libtommath/bn_mp_div_3.c b/libtommath/bn_mp_div_3.c index e8504ea..db46d44 100644 --- a/libtommath/bn_mp_div_3.c +++ b/libtommath/bn_mp_div_3.c @@ -1,4 +1,4 @@ -#include <tommath_private.h> +#include "tommath_private.h" #ifdef BN_MP_DIV_3_C /* LibTomMath, multiple-precision integer library -- Tom St Denis * @@ -9,71 +9,67 @@ * 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 + * SPDX-License-Identifier: Unlicense */ /* divide by three (based on routine from MPI and the GMP manual) */ -int -mp_div_3 (mp_int * a, mp_int *c, mp_digit * d) +int mp_div_3(const mp_int *a, mp_int *c, mp_digit *d) { - mp_int q; - mp_word w, t; - mp_digit b; - int res, ix; - - /* b = 2**DIGIT_BIT / 3 */ - b = (((mp_word)1) << ((mp_word)DIGIT_BIT)) / ((mp_word)3); + mp_int q; + mp_word w, t; + mp_digit b; + int res, ix; + + /* b = 2**DIGIT_BIT / 3 */ + b = ((mp_word)1 << (mp_word)DIGIT_BIT) / (mp_word)3; - if ((res = mp_init_size(&q, a->used)) != MP_OKAY) { - return res; - } - - q.used = a->used; - q.sign = a->sign; - w = 0; - for (ix = a->used - 1; ix >= 0; ix--) { - w = (w << ((mp_word)DIGIT_BIT)) | ((mp_word)a->dp[ix]); + if ((res = mp_init_size(&q, a->used)) != MP_OKAY) { + return res; + } - if (w >= 3) { - /* multiply w by [1/3] */ - t = (w * ((mp_word)b)) >> ((mp_word)DIGIT_BIT); + q.used = a->used; + q.sign = a->sign; + w = 0; + for (ix = a->used - 1; ix >= 0; ix--) { + w = (w << (mp_word)DIGIT_BIT) | (mp_word)a->dp[ix]; - /* now subtract 3 * [w/3] from w, to get the remainder */ - w -= t+t+t; + if (w >= 3u) { + /* multiply w by [1/3] */ + t = (w * (mp_word)b) >> (mp_word)DIGIT_BIT; - /* fixup the remainder as required since - * the optimization is not exact. - */ - while (w >= 3) { - t += 1; - w -= 3; - } + /* now subtract 3 * [w/3] from w, to get the remainder */ + w -= t+t+t; + + /* fixup the remainder as required since + * the optimization is not exact. + */ + while (w >= 3u) { + t += 1u; + w -= 3u; + } } else { - t = 0; + t = 0; } q.dp[ix] = (mp_digit)t; - } + } + + /* [optional] store the remainder */ + if (d != NULL) { + *d = (mp_digit)w; + } - /* [optional] store the remainder */ - if (d != NULL) { - *d = (mp_digit)w; - } + /* [optional] store the quotient */ + if (c != NULL) { + mp_clamp(&q); + mp_exch(&q, c); + } + mp_clear(&q); - /* [optional] store the quotient */ - if (c != NULL) { - mp_clamp(&q); - mp_exch(&q, c); - } - mp_clear(&q); - - return res; + return res; } #endif -/* ref: $Format:%D$ */ -/* git commit: $Format:%H$ */ -/* commit time: $Format:%ai$ */ +/* ref: HEAD -> master, tag: v1.1.0 */ +/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ +/* commit time: 2019-01-28 20:32:32 +0100 */ |