summaryrefslogtreecommitdiffstats
path: root/libtommath/bn_mp_prime_is_divisible.c
diff options
context:
space:
mode:
authorKevin B Kenny <kennykb@acm.org>2005-01-19 22:41:26 (GMT)
committerKevin B Kenny <kennykb@acm.org>2005-01-19 22:41:26 (GMT)
commitb9cf65a08e6a59e434685e894e3189c201ac6791 (patch)
tree1f0868ef44c9f17d83d10dc94343df7b8cfe1842 /libtommath/bn_mp_prime_is_divisible.c
parentc6a259aeeca4814a97cf6694814c63e74e4e18fa (diff)
downloadtcl-b9cf65a08e6a59e434685e894e3189c201ac6791.zip
tcl-b9cf65a08e6a59e434685e894e3189c201ac6791.tar.gz
tcl-b9cf65a08e6a59e434685e894e3189c201ac6791.tar.bz2
Import of libtommath 0.33
Diffstat (limited to 'libtommath/bn_mp_prime_is_divisible.c')
-rw-r--r--libtommath/bn_mp_prime_is_divisible.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/libtommath/bn_mp_prime_is_divisible.c b/libtommath/bn_mp_prime_is_divisible.c
new file mode 100644
index 0000000..f85fe7c
--- /dev/null
+++ b/libtommath/bn_mp_prime_is_divisible.c
@@ -0,0 +1,46 @@
+#include <tommath.h>
+#ifdef BN_MP_PRIME_IS_DIVISIBLE_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
+ */
+
+/* determines if an integers is divisible by one
+ * of the first PRIME_SIZE primes or not
+ *
+ * sets result to 0 if not, 1 if yes
+ */
+int mp_prime_is_divisible (mp_int * a, int *result)
+{
+ int err, ix;
+ mp_digit res;
+
+ /* default to not */
+ *result = MP_NO;
+
+ for (ix = 0; ix < PRIME_SIZE; ix++) {
+ /* what is a mod LBL_prime_tab[ix] */
+ if ((err = mp_mod_d (a, ltm_prime_tab[ix], &res)) != MP_OKAY) {
+ return err;
+ }
+
+ /* is the residue zero? */
+ if (res == 0) {
+ *result = MP_YES;
+ return MP_OKAY;
+ }
+ }
+
+ return MP_OKAY;
+}
+#endif