1 files changed, 44 insertions, 0 deletions
diff --git a/libtommath/bn_mp_mod.c b/libtommath/bn_mp_mod.c
new file mode 100644
index 0000000..75779bb
--- /dev/null
+++ b/libtommath/bn_mp_mod.c
@@ -0,0 +1,44 @@
+#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@iahu.ca, http://math.libtomcrypt.org
+ */
+
+/* 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