Mercurial > dropbear
diff libtommath/etc/2kprime.c @ 389:5ff8218bcee9
propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 2af95f00ebd5bb7a28b3817db1218442c935388e)
to branch 'au.asn.ucc.matt.dropbear' (head ecd779509ef23a8cdf64888904fc9b31d78aa933)
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Thu, 11 Jan 2007 03:14:55 +0000 |
parents | eed26cff980b |
children | 60fc6476e044 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libtommath/etc/2kprime.c Thu Jan 11 03:14:55 2007 +0000 @@ -0,0 +1,84 @@ +/* Makes safe primes of a 2k nature */ +#include <tommath.h> +#include <time.h> + +int sizes[] = {256, 512, 768, 1024, 1536, 2048, 3072, 4096}; + +int main(void) +{ + char buf[2000]; + int x, y; + mp_int q, p; + FILE *out; + clock_t t1; + mp_digit z; + + mp_init_multi(&q, &p, NULL); + + out = fopen("2kprime.1", "w"); + for (x = 0; x < (int)(sizeof(sizes) / sizeof(sizes[0])); x++) { + top: + mp_2expt(&q, sizes[x]); + mp_add_d(&q, 3, &q); + z = -3; + + t1 = clock(); + for(;;) { + mp_sub_d(&q, 4, &q); + z += 4; + + if (z > MP_MASK) { + printf("No primes of size %d found\n", sizes[x]); + break; + } + + if (clock() - t1 > CLOCKS_PER_SEC) { + printf("."); fflush(stdout); +// sleep((clock() - t1 + CLOCKS_PER_SEC/2)/CLOCKS_PER_SEC); + t1 = clock(); + } + + /* quick test on q */ + mp_prime_is_prime(&q, 1, &y); + if (y == 0) { + continue; + } + + /* find (q-1)/2 */ + mp_sub_d(&q, 1, &p); + mp_div_2(&p, &p); + mp_prime_is_prime(&p, 3, &y); + if (y == 0) { + continue; + } + + /* test on q */ + mp_prime_is_prime(&q, 3, &y); + if (y == 0) { + continue; + } + + break; + } + + if (y == 0) { + ++sizes[x]; + goto top; + } + + mp_toradix(&q, buf, 10); + printf("\n\n%d-bits (k = %lu) = %s\n", sizes[x], z, buf); + fprintf(out, "%d-bits (k = %lu) = %s\n", sizes[x], z, buf); fflush(out); + } + + return 0; +} + + + + + + +/* $Source: /cvs/libtom/libtommath/etc/2kprime.c,v $ */ +/* $Revision: 1.2 $ */ +/* $Date: 2005/05/05 14:38:47 $ */