diff options
Diffstat (limited to 'libtommath/etc/drprime.c')
-rw-r--r-- | libtommath/etc/drprime.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/libtommath/etc/drprime.c b/libtommath/etc/drprime.c new file mode 100644 index 0000000..b0cc37b --- /dev/null +++ b/libtommath/etc/drprime.c @@ -0,0 +1,64 @@ +/* Makes safe primes of a DR nature */ +#include <tommath.h> + +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 }; +int main(void) +{ + int res, x, y; + char buf[4096]; + FILE *out; + mp_int a, b; + + mp_init(&a); + mp_init(&b); + + out = fopen("drprimes.txt", "w"); + for (x = 0; x < (int)(sizeof(sizes)/sizeof(sizes[0])); x++) { + top: + printf("Seeking a %d-bit safe prime\n", sizes[x] * DIGIT_BIT); + mp_grow(&a, sizes[x]); + mp_zero(&a); + for (y = 1; y < sizes[x]; y++) { + a.dp[y] = MP_MASK; + } + + /* make a DR modulus */ + a.dp[0] = -1; + a.used = sizes[x]; + + /* now loop */ + res = 0; + for (;;) { + a.dp[0] += 4; + if (a.dp[0] >= MP_MASK) break; + mp_prime_is_prime(&a, 1, &res); + if (res == 0) continue; + printf("."); fflush(stdout); + mp_sub_d(&a, 1, &b); + mp_div_2(&b, &b); + mp_prime_is_prime(&b, 3, &res); + if (res == 0) continue; + mp_prime_is_prime(&a, 3, &res); + if (res == 1) break; + } + + if (res != 1) { + printf("Error not DR modulus\n"); sizes[x] += 1; goto top; + } else { + mp_toradix(&a, buf, 10); + printf("\n\np == %s\n\n", buf); + fprintf(out, "%d-bit prime:\np == %s\n\n", mp_count_bits(&a), buf); fflush(out); + } + } + fclose(out); + + mp_clear(&a); + mp_clear(&b); + + return 0; +} + + +/* $Source: /root/tcl/repos-to-convert/tcl/libtommath/etc/drprime.c,v $ */ +/* $Revision: 1.1.1.1.2.1 $ */ +/* $Date: 2005/09/26 20:16:54 $ */ |