--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bn_mp_radix_size.c	Mon May 31 18:25:22 2004 +0000
@@ -0,0 +1,65 @@
+/* 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>
+
+/* returns size of ASCII reprensentation */
+int mp_radix_size (mp_int * a, int radix, int *size)
+{
+  int     res, digs;
+  mp_int  t;
+  mp_digit d;
+
+  *size = 0;
+
+  /* special case for binary */
+  if (radix == 2) {
+    *size = mp_count_bits (a) + (a->sign == MP_NEG ? 1 : 0) + 1;
+    return MP_OKAY;
+  }
+
+  /* make sure the radix is in range */
+  if (radix < 2 || radix > 64) {
+    return MP_VAL;
+  }
+
+  /* init a copy of the input */
+  if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
+    return res;
+  }
+
+  /* digs is the digit count */
+  digs = 0;
+
+  /* if it's negative add one for the sign */
+  if (t.sign == MP_NEG) {
+    ++digs;
+    t.sign = MP_ZPOS;
+  }
+
+  /* fetch out all of the digits */
+  while (mp_iszero (&t) == 0) {
+    if ((res = mp_div_d (&t, (mp_digit) radix, &t, &d)) != MP_OKAY) {
+      mp_clear (&t);
+      return res;
+    }
+    ++digs;
+  }
+  mp_clear (&t);
+
+  /* return digs + 1, the 1 is for the NULL byte that would be required. */
+  *size = digs + 1;
+  return MP_OKAY;
+}
+