diff libtommath/bn_mp_clamp.c @ 391:00fcf5045160

propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head c1db4398d56c56c6d06ae1e20c1e0d04dbb598ed) to branch 'au.asn.ucc.matt.dropbear' (head d26d5eb2837f46b56a33fb0e7573aa0201abd4d5)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 04:29:08 +0000
parents 5ff8218bcee9
children 60fc6476e044
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtommath/bn_mp_clamp.c	Thu Jan 11 04:29:08 2007 +0000
@@ -0,0 +1,44 @@
+#include <tommath.h>
+#ifdef BN_MP_CLAMP_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, [email protected], http://math.libtomcrypt.com
+ */
+
+/* trim unused digits 
+ *
+ * This is used to ensure that leading zero digits are
+ * trimed and the leading "used" digit will be non-zero
+ * Typically very fast.  Also fixes the sign if there
+ * are no more leading digits
+ */
+void
+mp_clamp (mp_int * a)
+{
+  /* decrease used while the most significant digit is
+   * zero.
+   */
+  while (a->used > 0 && a->dp[a->used - 1] == 0) {
+    --(a->used);
+  }
+
+  /* reset the sign flag if used == 0 */
+  if (a->used == 0) {
+    a->sign = MP_ZPOS;
+  }
+}
+#endif
+
+/* $Source: /cvs/libtom/libtommath/bn_mp_clamp.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2006/03/31 14:18:44 $ */