2 #ifdef BN_MP_PRIME_IS_PRIME_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
5 * LibTomMath is a library that provides multiple-precision
6 * integer arithmetic as well as number theoretic functionality.
8 * The library was designed directly after the MPI library by
9 * Michael Fromberger but has been written from scratch with
10 * additional optimizations in place.
12 * The library is free for all purposes without any express
15 * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
18 /* performs a variable number of rounds of Miller-Rabin
20 * Probability of error after t rounds is no more than
23 * Sets result to 1 if probably prime, 0 otherwise
25 int mp_prime_is_prime (mp_int * a, int t, int *result)
33 /* valid value of t? */
34 if (t <= 0 || t > PRIME_SIZE) {
38 /* is the input equal to one of the primes in the table? */
39 for (ix = 0; ix < PRIME_SIZE; ix++) {
40 if (mp_cmp_d(a, ltm_prime_tab[ix]) == MP_EQ) {
46 /* first perform trial division */
47 if ((err = mp_prime_is_divisible (a, &res)) != MP_OKAY) {
51 /* return if it was trivially divisible */
56 /* now perform the miller-rabin rounds */
57 if ((err = mp_init (&b)) != MP_OKAY) {
61 for (ix = 0; ix < t; ix++) {
63 mp_set (&b, ltm_prime_tab[ix]);
65 if ((err = mp_prime_miller_rabin (a, &b, &res)) != MP_OKAY) {