Added libtommath for bignum operations.

1 files changed, 45 insertions, 0 deletions

diff --git a/libtommath/bn_mp_get_int.c b/libtommath/bn_mp_get_int.c
new file mode 100644
index 0000000..17162e2
--- /dev/null
+++ b/libtommath/bn_mp_get_int.c
@@ -0,0 +1,45 @@
+#include <tommath.h>
+#ifdef BN_MP_GET_INT_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://libtom.org
+ */
+
+/* get the lower 32-bits of an mp_int */
+unsigned long mp_get_int(mp_int * a) 
+{
+  int i;
+  unsigned long res;
+
+  if (a->used == 0) {
+     return 0;
+  }
+
+  /* get number of digits of the lsb we have to read */
+  i = MIN(a->used,(int)((sizeof(unsigned long)*CHAR_BIT+DIGIT_BIT-1)/DIGIT_BIT))-1;
+
+  /* get most significant digit of result */
+  res = DIGIT(a,i);
+   
+  while (--i >= 0) {
+    res = (res << DIGIT_BIT) | DIGIT(a,i);
+  }
+
+  /* force result to 32-bits always so it is consistent on non 32-bit platforms */
+  return res & 0xFFFFFFFFUL;
+}
+#endif
+
+/* $Source: /cvs/libtom/libtommath/bn_mp_get_int.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/12/28 01:25:13 $ */