diff options
Diffstat (limited to 'libtommath/bn_mp_prime_random_ex.c')
-rw-r--r-- | libtommath/bn_mp_prime_random_ex.c | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/libtommath/bn_mp_prime_random_ex.c b/libtommath/bn_mp_prime_random_ex.c index cf5272e..d3d6f3d 100644 --- a/libtommath/bn_mp_prime_random_ex.c +++ b/libtommath/bn_mp_prime_random_ex.c @@ -18,7 +18,7 @@ /* makes a truly random prime of a given size (bits), * * Flags are as follows: - * + * * LTM_PRIME_BBS - make prime congruent to 3 mod 4 * LTM_PRIME_SAFE - make sure (p-1)/2 is prime as well (implies LTM_PRIME_BBS) * LTM_PRIME_2MSB_ON - make the 2nd highest bit one @@ -62,7 +62,7 @@ int mp_prime_random_ex(mp_int *a, int t, int size, int flags, ltm_prime_callback maskOR_msb_offset = ((size & 7) == 1) ? 1 : 0; if ((flags & LTM_PRIME_2MSB_ON) != 0) { maskOR_msb |= 0x80 >> ((9 - size) & 7); - } + } /* get the maskOR_lsb */ maskOR_lsb = 1; @@ -76,7 +76,7 @@ int mp_prime_random_ex(mp_int *a, int t, int size, int flags, ltm_prime_callback err = MP_VAL; goto error; } - + /* work over the MSbyte */ tmp[0] &= maskAND; tmp[0] |= 1 << ((size - 1) & 7); @@ -86,28 +86,42 @@ int mp_prime_random_ex(mp_int *a, int t, int size, int flags, ltm_prime_callback tmp[bsize-1] |= maskOR_lsb; /* read it in */ - if ((err = mp_read_unsigned_bin(a, tmp, bsize)) != MP_OKAY) { goto error; } + if ((err = mp_read_unsigned_bin(a, tmp, bsize)) != MP_OKAY) { + goto error; + } /* is it prime? */ - if ((err = mp_prime_is_prime(a, t, &res)) != MP_OKAY) { goto error; } - if (res == MP_NO) { + if ((err = mp_prime_is_prime(a, t, &res)) != MP_OKAY) { + goto error; + } + if (res == MP_NO) { continue; } if ((flags & LTM_PRIME_SAFE) != 0) { /* see if (a-1)/2 is prime */ - if ((err = mp_sub_d(a, 1, a)) != MP_OKAY) { goto error; } - if ((err = mp_div_2(a, a)) != MP_OKAY) { goto error; } - + if ((err = mp_sub_d(a, 1, a)) != MP_OKAY) { + goto error; + } + if ((err = mp_div_2(a, a)) != MP_OKAY) { + goto error; + } + /* is it prime? */ - if ((err = mp_prime_is_prime(a, t, &res)) != MP_OKAY) { goto error; } + if ((err = mp_prime_is_prime(a, t, &res)) != MP_OKAY) { + goto error; + } } } while (res == MP_NO); if ((flags & LTM_PRIME_SAFE) != 0) { /* restore a to the original value */ - if ((err = mp_mul_2(a, a)) != MP_OKAY) { goto error; } - if ((err = mp_add_d(a, 1, a)) != MP_OKAY) { goto error; } + if ((err = mp_mul_2(a, a)) != MP_OKAY) { + goto error; + } + if ((err = mp_add_d(a, 1, a)) != MP_OKAY) { + goto error; + } } err = MP_OKAY; |