diff bn_mp_to_unsigned_bin.c @ 1:22d5cf7d4b1a libtommath

Renaming branch
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:23:46 +0000
parents
children d29b64170cf0
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bn_mp_to_unsigned_bin.c	Mon May 31 18:23:46 2004 +0000
@@ -0,0 +1,43 @@
+/* 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.org
+ */
+#include <tommath.h>
+
+/* store in unsigned [big endian] format */
+int
+mp_to_unsigned_bin (mp_int * a, unsigned char *b)
+{
+  int     x, res;
+  mp_int  t;
+
+  if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
+    return res;
+  }
+
+  x = 0;
+  while (mp_iszero (&t) == 0) {
+#ifndef MP_8BIT
+      b[x++] = (unsigned char) (t.dp[0] & 255);
+#else
+      b[x++] = (unsigned char) (t.dp[0] | ((t.dp[1] & 0x01) << 7));
+#endif
+    if ((res = mp_div_2d (&t, 8, &t, NULL)) != MP_OKAY) {
+      mp_clear (&t);
+      return res;
+    }
+  }
+  bn_reverse (b, x);
+  mp_clear (&t);
+  return MP_OKAY;
+}