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-rw-r--r--libtommath/bn_mp_mod.c44
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diff --git a/libtommath/bn_mp_mod.c b/libtommath/bn_mp_mod.c
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+#include <tommath.h>
+#ifdef BN_MP_MOD_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@gmail.com, http://math.libtomcrypt.com
+ */
+
+/* c = a mod b, 0 <= c < b */
+int
+mp_mod (mp_int * a, mp_int * b, mp_int * c)
+{
+ mp_int t;
+ int res;
+
+ if ((res = mp_init (&t)) != MP_OKAY) {
+ return res;
+ }
+
+ if ((res = mp_div (a, b, NULL, &t)) != MP_OKAY) {
+ mp_clear (&t);
+ return res;
+ }
+
+ if (t.sign != b->sign) {
+ res = mp_add (b, &t, c);
+ } else {
+ res = MP_OKAY;
+ mp_exch (&t, c);
+ }
+
+ mp_clear (&t);
+ return res;
+}
+#endif