propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)

            to branch 'au.asn.ucc.matt.dropbear' (head fdf4a7a3b97ae5046139915de7e40399cceb2c01)

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extra : convert_revision : dc4809882e1b9f2dcd3f8bbe38c74a0a52c39ce4

1 files changed, 41 insertions, 0 deletions

diff --git a/libtommath/bn_mp_count_bits.c b/libtommath/bn_mp_count_bits.c
new file mode 100644
index 0000000..f3f85ac
--- /dev/null
+++ b/libtommath/bn_mp_count_bits.c
@@ -0,0 +1,41 @@
+#include <tommath.h>
+#ifdef BN_MP_COUNT_BITS_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
+ */
+
+/* returns the number of bits in an int */
+int
+mp_count_bits (mp_int * a)
+{
+  int     r;
+  mp_digit q;
+
+  /* shortcut */
+  if (a->used == 0) {
+    return 0;
+  }
+
+  /* get number of digits and add that */
+  r = (a->used - 1) * DIGIT_BIT;
+  
+  /* take the last digit and count the bits in it */
+  q = a->dp[a->used - 1];
+  while (q > ((mp_digit) 0)) {
+    ++r;
+    q >>= ((mp_digit) 1);
+  }
+  return r;
+}
+#endif