crypto/external/bsd/heimdal/dist/lib/hcrypto/libtommath/etc/drprime.c

   1 /*      $NetBSD: drprime.c,v 1.1.1.2 2014/04/24 12:45:39 pettai Exp $   */
   2
   3 /* Makes safe primes of a DR nature */
   4 #include <tommath.h>
   5
   6 int sizes[] = { 1+256/DIGIT_BIT, 1+512/DIGIT_BIT, 1+768/DIGIT_BIT, 1+1024/DIGIT_BIT, 1+2048/DIGIT_BIT, 1+4096/DIGIT_BIT };
   7 int main(void)
   8 {
   9    int res, x, y;
  10    char buf[4096];
  11    FILE *out;
  12    mp_int a, b;
  13
  14    mp_init(&a);
  15    mp_init(&b);
  16
  17    out = fopen("drprimes.txt", "w");
  18    for (x = 0; x < (int)(sizeof(sizes)/sizeof(sizes[0])); x++) {
  19    top:
  20        printf("Seeking a %d-bit safe prime\n", sizes[x] * DIGIT_BIT);
  21        mp_grow(&a, sizes[x]);
  22        mp_zero(&a);
  23        for (y = 1; y < sizes[x]; y++) {
  24            a.dp[y] = MP_MASK;
  25        }
  26
  27        /* make a DR modulus */
  28        a.dp[0] = -1;
  29        a.used = sizes[x];
  30
  31        /* now loop */
  32        res = 0;
  33        for (;;) {
  34           a.dp[0] += 4;
  35           if (a.dp[0] >= MP_MASK) break;
  36           mp_prime_is_prime(&a, 1, &res);
  37           if (res == 0) continue;
  38           printf("."); fflush(stdout);
  39           mp_sub_d(&a, 1, &b);
  40           mp_div_2(&b, &b);
  41           mp_prime_is_prime(&b, 3, &res);
  42           if (res == 0) continue;
  43           mp_prime_is_prime(&a, 3, &res);
  44           if (res == 1) break;
  45         }
  46
  47         if (res != 1) {
  48            printf("Error not DR modulus\n"); sizes[x] += 1; goto top;
  49         } else {
  50            mp_toradix(&a, buf, 10);
  51            printf("\n\np == %s\n\n", buf);
  52            fprintf(out, "%d-bit prime:\np == %s\n\n", mp_count_bits(&a), buf); fflush(out);
  53         }
  54    }
  55    fclose(out);
  56
  57    mp_clear(&a);
  58    mp_clear(&b);
  59
  60    return 0;
  61 }
  62
  63
  64 /* Source: /cvs/libtom/libtommath/etc/drprime.c,v  */
  65 /* Revision: 1.2  */
  66 /* Date: 2005/05/05 14:38:47  */