1 files changed, 45 insertions, 0 deletions
diff --git a/libtommath/bn_mp_to_unsigned_bin.c b/libtommath/bn_mp_to_unsigned_bin.c
new file mode 100644
index 0000000..763e346
--- /dev/null
+++ b/libtommath/bn_mp_to_unsigned_bin.c
@@ -0,0 +1,45 @@
+#include <tommath.h>
+#ifdef BN_MP_TO_UNSIGNED_BIN_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
+ */
+
+/* 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;
+}
+#endif