Generate safe primes not divisible by 3, 5 or 7.

~2% speed improvement on trial division.
This commit is contained in:
Felix Laurie von Massenbach 2014-05-27 02:12:59 +01:00 committed by Ben Laurie
parent b0513819e0
commit c09ec5d2a0
3 changed files with 21 additions and 11 deletions

View file

@ -56,7 +56,7 @@
* [including the GNU Public Licence.] * [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 * Portions of the attached software ("Contribution") are developed by
* SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
@ -2054,7 +2054,7 @@ int MAIN(int argc, char **argv)
Time_F(START); Time_F(START);
for (count=0, run=1; COND(prime_c[D_PRIME_COPRIME]); count++) 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); d=Time_F(STOP);
prime_print_result(D_PRIME_COPRIME, count, d); 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) static void prime_print_result(int alg, int count, double time_used)
{ {
BIO_printf(bio_err, 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, count, prime_names[alg], time_used,
time_used / ((double)count) * 1000); time_used / ((double)count) * 1000000);
} }
#ifndef NO_FORK #ifndef NO_FORK

View file

@ -536,7 +536,7 @@ BIGNUM *int_bn_mod_inverse(BIGNUM *in,
int bn_probable_prime_dh(BIGNUM *rnd, int bits, int bn_probable_prime_dh(BIGNUM *rnd, int bits,
const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx); 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); const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx);
#ifdef __cplusplus #ifdef __cplusplus

View file

@ -134,7 +134,10 @@ static int probable_prime_dh(BIGNUM *rnd, const BIGNUM *add,
static int probable_prime_dh_safe(BIGNUM *rnd, int bits, static int probable_prime_dh_safe(BIGNUM *rnd, int bits,
const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx); 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) 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)); 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) const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx)
{ {
int i = prime_offset_count;
BIGNUM *offset_index = BN_new(); BIGNUM *offset_index = BN_new();
if (!BN_rand(rnd, bits, 0, 1)) return(0); if (!BN_rand(rnd, bits, 0, 1)) return(0);
if (!BN_rand(offset_index, 3, -1, -1)) return(0);
BN_mul_word(rnd, 30); while (i >= prime_offset_count)
BN_add_word(rnd, prime_offsets[BN_get_word(offset_index)]); {
if (!BN_rand(offset_index, prime_offset_count_exponent, -1, -1))
return(0);
i = BN_get_word(offset_index);
}
BN_mul_word(rnd, prime_multiplier);
BN_add_word(rnd, prime_offsets[i]);
BN_free(offset_index); 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, static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1,