diff options
Diffstat (limited to 'libtommath/bn_mp_prime_next_prime.c')
| -rw-r--r-- | libtommath/bn_mp_prime_next_prime.c | 86 |
1 files changed, 44 insertions, 42 deletions
diff --git a/libtommath/bn_mp_prime_next_prime.c b/libtommath/bn_mp_prime_next_prime.c index 7a32d9b..f383cbb 100644 --- a/libtommath/bn_mp_prime_next_prime.c +++ b/libtommath/bn_mp_prime_next_prime.c @@ -38,28 +38,28 @@ int mp_prime_next_prime(mp_int *a, int t, int bbs_style) if (mp_cmp_d(a, ltm_prime_tab[PRIME_SIZE-1]) == MP_LT) { /* find which prime it is bigger than */ for (x = PRIME_SIZE - 2; x >= 0; x--) { - if (mp_cmp_d(a, ltm_prime_tab[x]) != MP_LT) { - if (bbs_style == 1) { - /* ok we found a prime smaller or - * equal [so the next is larger] - * - * however, the prime must be - * congruent to 3 mod 4 - */ - if ((ltm_prime_tab[x + 1] & 3) != 3) { - /* scan upwards for a prime congruent to 3 mod 4 */ - for (y = x + 1; y < PRIME_SIZE; y++) { - if ((ltm_prime_tab[y] & 3) == 3) { - mp_set(a, ltm_prime_tab[y]); - return MP_OKAY; - } - } - } - } else { - mp_set(a, ltm_prime_tab[x + 1]); - return MP_OKAY; - } - } + if (mp_cmp_d(a, ltm_prime_tab[x]) != MP_LT) { + if (bbs_style == 1) { + /* ok we found a prime smaller or + * equal [so the next is larger] + * + * however, the prime must be + * congruent to 3 mod 4 + */ + if ((ltm_prime_tab[x + 1] & 3) != 3) { + /* scan upwards for a prime congruent to 3 mod 4 */ + for (y = x + 1; y < PRIME_SIZE; y++) { + if ((ltm_prime_tab[y] & 3) == 3) { + mp_set(a, ltm_prime_tab[y]); + return MP_OKAY; + } + } + } + } else { + mp_set(a, ltm_prime_tab[x + 1]); + return MP_OKAY; + } + } } /* at this point a maybe 1 */ if (mp_cmp_d(a, 1) == MP_EQ) { @@ -81,7 +81,9 @@ int mp_prime_next_prime(mp_int *a, int t, int bbs_style) if (bbs_style == 1) { /* if a mod 4 != 3 subtract the correct value to make it so */ if ((a->dp[0] & 3) != 3) { - if ((err = mp_sub_d(a, (a->dp[0] & 3) + 1, a)) != MP_OKAY) { return err; }; + if ((err = mp_sub_d(a, (a->dp[0] & 3) + 1, a)) != MP_OKAY) { + return err; + }; } } else { if (mp_iseven(a) == MP_YES) { @@ -116,18 +118,18 @@ int mp_prime_next_prime(mp_int *a, int t, int bbs_style) /* compute the new residue without using division */ for (x = 1; x < PRIME_SIZE; x++) { - /* add the step to each residue */ - res_tab[x] += kstep; - - /* subtract the modulus [instead of using division] */ - if (res_tab[x] >= ltm_prime_tab[x]) { - res_tab[x] -= ltm_prime_tab[x]; - } - - /* set flag if zero */ - if (res_tab[x] == 0) { - y = 1; - } + /* add the step to each residue */ + res_tab[x] += kstep; + + /* subtract the modulus [instead of using division] */ + if (res_tab[x] >= ltm_prime_tab[x]) { + res_tab[x] -= ltm_prime_tab[x]; + } + + /* set flag if zero */ + if (res_tab[x] == 0) { + y = 1; + } } } while ((y == 1) && (step < ((((mp_digit)1) << DIGIT_BIT) - kstep))); @@ -143,13 +145,13 @@ int mp_prime_next_prime(mp_int *a, int t, int bbs_style) /* is this prime? */ for (x = 0; x < t; x++) { - mp_set(&b, ltm_prime_tab[x]); - if ((err = mp_prime_miller_rabin(a, &b, &res)) != MP_OKAY) { - goto LBL_ERR; - } - if (res == MP_NO) { - break; - } + mp_set(&b, ltm_prime_tab[x]); + if ((err = mp_prime_miller_rabin(a, &b, &res)) != MP_OKAY) { + goto LBL_ERR; + } + if (res == MP_NO) { + break; + } } if (res == MP_YES) { |