From c09ec5d2a0e368b18efc1cbf2444fdb37ca7270b Mon Sep 17 00:00:00 2001 From: Felix Laurie von Massenbach Date: Tue, 27 May 2014 02:12:59 +0100 Subject: [PATCH] Generate safe primes not divisible by 3, 5 or 7. ~2% speed improvement on trial division. --- apps/speed.c | 8 ++++---- crypto/bn/bn_lcl.h | 2 +- crypto/bn/bn_prime.c | 22 ++++++++++++++++------ 3 files changed, 21 insertions(+), 11 deletions(-) diff --git a/apps/speed.c b/apps/speed.c index 84d0829ad2..78b79239b2 100644 --- a/apps/speed.c +++ b/apps/speed.c @@ -56,7 +56,7 @@ * [including the GNU Public Licence.] */ /* ==================================================================== - * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. + * Copyright 2002-2014 Sun Microsystems, Inc. ALL RIGHTS RESERVED. * * Portions of the attached software ("Contribution") are developed by * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. @@ -2054,7 +2054,7 @@ int MAIN(int argc, char **argv) Time_F(START); for (count=0, run=1; COND(prime_c[D_PRIME_COPRIME]); count++) - bn_probable_prime_dh_coprime(rnd, 1024, add, NULL, ctx); + bn_probable_prime_dh_coprime_safe(rnd, 1024, add, NULL, ctx); d=Time_F(STOP); prime_print_result(D_PRIME_COPRIME, count, d); @@ -2700,9 +2700,9 @@ static void print_result(int alg,int run_no,int count,double time_used) static void prime_print_result(int alg, int count, double time_used) { BIO_printf(bio_err, - mr ? "+R:%d:%s:%f:%f\n" : "%d %s's in %.2fs (%.2fms/run)\n", + mr ? "+R:%d:%s:%f:%f\n" : "%d %s's in %.2fs (%.2f microseconds / run)\n", count, prime_names[alg], time_used, - time_used / ((double)count) * 1000); + time_used / ((double)count) * 1000000); } #ifndef NO_FORK diff --git a/crypto/bn/bn_lcl.h b/crypto/bn/bn_lcl.h index fc54dcecdc..f0cfaeaaba 100644 --- a/crypto/bn/bn_lcl.h +++ b/crypto/bn/bn_lcl.h @@ -536,7 +536,7 @@ BIGNUM *int_bn_mod_inverse(BIGNUM *in, int bn_probable_prime_dh(BIGNUM *rnd, int bits, const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx); -int bn_probable_prime_dh_coprime(BIGNUM *rnd, int bits, +int bn_probable_prime_dh_coprime_safe(BIGNUM *rnd, int bits, const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx); #ifdef __cplusplus diff --git a/crypto/bn/bn_prime.c b/crypto/bn/bn_prime.c index b303a48726..90f840fdd9 100644 --- a/crypto/bn/bn_prime.c +++ b/crypto/bn/bn_prime.c @@ -134,7 +134,10 @@ static int probable_prime_dh(BIGNUM *rnd, const BIGNUM *add, static int probable_prime_dh_safe(BIGNUM *rnd, int bits, const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx); -static int prime_offsets[8] = { 7, 11, 13, 17, 19, 23, 29, 31 }; +static int prime_multiplier = 210; +static int prime_offsets[8] = { 23, 47, 59, 83, 107, 143, 167, 179 }; +static int prime_offset_count = 8; +static int prime_offset_count_exponent = 3; int BN_GENCB_call(BN_GENCB *cb, int a, int b) { @@ -372,20 +375,27 @@ int bn_probable_prime_dh(BIGNUM *rnd, int bits, return(probable_prime_dh(rnd, add, rem, ctx, 1)); } -int bn_probable_prime_dh_coprime(BIGNUM *rnd, int bits, +int bn_probable_prime_dh_coprime_safe(BIGNUM *rnd, int bits, const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx) { + int i = prime_offset_count; BIGNUM *offset_index = BN_new(); if (!BN_rand(rnd, bits, 0, 1)) return(0); - if (!BN_rand(offset_index, 3, -1, -1)) return(0); + + while (i >= prime_offset_count) + { + if (!BN_rand(offset_index, prime_offset_count_exponent, -1, -1)) + return(0); + i = BN_get_word(offset_index); + } - BN_mul_word(rnd, 30); - BN_add_word(rnd, prime_offsets[BN_get_word(offset_index)]); + BN_mul_word(rnd, prime_multiplier); + BN_add_word(rnd, prime_offsets[i]); BN_free(offset_index); - return(probable_prime_dh(rnd, add, rem, ctx, 3)); + return(probable_prime_dh(rnd, add, rem, ctx, 4)); } static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1, -- GitLab