diff options
Diffstat (limited to 'crypto/bn/bn_prime.c')
| -rw-r--r-- | crypto/bn/bn_prime.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/crypto/bn/bn_prime.c b/crypto/bn/bn_prime.c index d03403a600..7b25979dd1 100644 --- a/crypto/bn/bn_prime.c +++ b/crypto/bn/bn_prime.c @@ -258,7 +258,8 @@ int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed, /* first look for small factors */ if (!BN_is_odd(a)) - return 0; + /* a is even => a is prime if and only if a == 2 */ + return BN_is_word(a, 2); if (do_trial_division) { for (i = 1; i < NUMPRIMES; i++) @@ -376,14 +377,15 @@ static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1, static int probable_prime(BIGNUM *rnd, int bits) { int i; - BN_ULONG mods[NUMPRIMES]; - BN_ULONG delta,d; + prime_t mods[NUMPRIMES]; + BN_ULONG delta,maxdelta; again: if (!BN_rand(rnd,bits,1,1)) return(0); /* we now have a random number 'rand' to test. */ for (i=1; i<NUMPRIMES; i++) - mods[i]=BN_mod_word(rnd,(BN_ULONG)primes[i]); + mods[i]=(prime_t)BN_mod_word(rnd,(BN_ULONG)primes[i]); + maxdelta=BN_MASK2 - primes[NUMPRIMES-1]; delta=0; loop: for (i=1; i<NUMPRIMES; i++) { @@ -391,12 +393,8 @@ again: * that gcd(rnd-1,primes) == 1 (except for 2) */ if (((mods[i]+delta)%primes[i]) <= 1) { - d=delta; delta+=2; - /* perhaps need to check for overflow of - * delta (but delta can be up to 2^32) - * 21-May-98 eay - added overflow check */ - if (delta < d) goto again; + if (delta > maxdelta) goto again; goto loop; } } |