Mercurial > dropbear
view libtommath/bn_mp_prime_rabin_miller_trials.c @ 1656:a36e545fb43d
Prime-related bugfixes (#81)
* Merge pull request #180 from czurnieden/isprimeerror
Fixed bug in mp_prime_isprime
(cherry picked from commit f3ff7064f3301a2fc11b84d389fd67769862d437)
* do 2 MR rounds for numbers >=2048bits
* back-port modified mp_prime_next_prime()
author | Steffen Jaeckel <s@jaeckel.eu> |
---|---|
date | Tue, 17 Sep 2019 16:11:09 +0200 |
parents | f52919ffd3b1 |
children | 1051e4eea25a |
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#include "tommath_private.h" #ifdef BN_MP_PRIME_RABIN_MILLER_TRIALS_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 */ static const struct { int k, t; } sizes[] = { { 80, -1 }, /* Use deterministic algorithm for size <= 80 bits */ { 81, 39 }, { 96, 37 }, { 128, 32 }, { 160, 27 }, { 192, 21 }, { 256, 16 }, { 384, 10 }, { 512, 7 }, { 640, 6 }, { 768, 5 }, { 896, 4 }, { 1024, 4 }, { 2048, 2 } /* For bigger keysizes use always at least 2 Rounds */ }; /* returns # of RM trials required for a given bit size and max. error of 2^(-96)*/ int mp_prime_rabin_miller_trials(int size) { int x; for (x = 0; x < (int)(sizeof(sizes)/(sizeof(sizes[0]))); x++) { if (sizes[x].k == size) { return sizes[x].t; } else if (sizes[x].k > size) { return (x == 0) ? sizes[0].t : sizes[x - 1].t; } } return sizes[x-1].t; } #endif /* ref: HEAD -> master, tag: v1.1.0 */ /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ /* commit time: 2019-01-28 20:32:32 +0100 */