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-rw-r--r--libtommath/bn_mp_prime_is_prime.c79
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diff --git a/libtommath/bn_mp_prime_is_prime.c b/libtommath/bn_mp_prime_is_prime.c
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+#include <tommath.h>
+#ifdef BN_MP_PRIME_IS_PRIME_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
+ */
+
+/* performs a variable number of rounds of Miller-Rabin
+ *
+ * Probability of error after t rounds is no more than
+
+ *
+ * Sets result to 1 if probably prime, 0 otherwise
+ */
+int mp_prime_is_prime (mp_int * a, int t, int *result)
+{
+ mp_int b;
+ int ix, err, res;
+
+ /* default to no */
+ *result = MP_NO;
+
+ /* valid value of t? */
+ if (t <= 0 || t > PRIME_SIZE) {
+ return MP_VAL;
+ }
+
+ /* is the input equal to one of the primes in the table? */
+ for (ix = 0; ix < PRIME_SIZE; ix++) {
+ if (mp_cmp_d(a, ltm_prime_tab[ix]) == MP_EQ) {
+ *result = 1;
+ return MP_OKAY;
+ }
+ }
+
+ /* first perform trial division */
+ if ((err = mp_prime_is_divisible (a, &res)) != MP_OKAY) {
+ return err;
+ }
+
+ /* return if it was trivially divisible */
+ if (res == MP_YES) {
+ return MP_OKAY;
+ }
+
+ /* now perform the miller-rabin rounds */
+ if ((err = mp_init (&b)) != MP_OKAY) {
+ return err;
+ }
+
+ for (ix = 0; ix < t; ix++) {
+ /* set the prime */
+ mp_set (&b, ltm_prime_tab[ix]);
+
+ if ((err = mp_prime_miller_rabin (a, &b, &res)) != MP_OKAY) {
+ goto LBL_B;
+ }
+
+ if (res == MP_NO) {
+ goto LBL_B;
+ }
+ }
+
+ /* passed the test */
+ *result = MP_YES;
+LBL_B:mp_clear (&b);
+ return err;
+}
+#endif