82 lines
1.8 KiB
C
82 lines
1.8 KiB
C
/* Makes safe primes of a 2k nature */
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#include <tommath.h>
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#include <time.h>
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static int sizes[] = {256, 512, 768, 1024, 1536, 2048, 3072, 4096};
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int main(void)
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{
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char buf[2000];
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size_t x;
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int y;
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mp_int q, p;
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FILE *out;
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clock_t t1;
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mp_digit z;
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mp_init_multi(&q, &p, NULL);
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out = fopen("2kprime.1", "w");
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if (out != NULL) {
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for (x = 0; x < (sizeof(sizes) / sizeof(sizes[0])); x++) {
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top:
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mp_2expt(&q, sizes[x]);
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mp_add_d(&q, 3uL, &q);
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z = -3;
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t1 = clock();
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for (;;) {
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mp_sub_d(&q, 4uL, &q);
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z += 4uL;
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if (z > MP_MASK) {
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printf("No primes of size %d found\n", sizes[x]);
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break;
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}
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if ((clock() - t1) > CLOCKS_PER_SEC) {
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printf(".");
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fflush(stdout);
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/* sleep((clock() - t1 + CLOCKS_PER_SEC/2)/CLOCKS_PER_SEC); */
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t1 = clock();
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}
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/* quick test on q */
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mp_prime_is_prime(&q, 1, &y);
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if (y == 0) {
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continue;
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}
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/* find (q-1)/2 */
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mp_sub_d(&q, 1uL, &p);
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mp_div_2(&p, &p);
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mp_prime_is_prime(&p, 3, &y);
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if (y == 0) {
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continue;
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}
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/* test on q */
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mp_prime_is_prime(&q, 3, &y);
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if (y == 0) {
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continue;
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}
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break;
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}
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if (y == 0) {
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++sizes[x];
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goto top;
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}
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mp_toradix(&q, buf, 10);
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printf("\n\n%d-bits (k = %lu) = %s\n", sizes[x], z, buf);
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fprintf(out, "%d-bits (k = %lu) = %s\n", sizes[x], z, buf);
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fflush(out);
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}
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fclose(out);
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}
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return 0;
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}
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