Import code from previous AssetBuilder version

thirdparty/libtommath/bn_mp_toradix_n.c

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+#include "tommath_private.h"
+#ifdef BN_MP_TORADIX_N_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.
+ *
+ * SPDX-License-Identifier: Unlicense
+ */
+
+/* stores a bignum as a ASCII string in a given radix (2..64)
+ *
+ * Stores upto maxlen-1 chars and always a NULL byte
+ */
+int mp_toradix_n(const mp_int *a, char *str, int radix, int maxlen)
+{
+   int     res, digs;
+   mp_int  t;
+   mp_digit d;
+   char   *_s = str;
+
+   /* check range of the maxlen, radix */
+   if ((maxlen < 2) || (radix < 2) || (radix > 64)) {
+      return MP_VAL;
+   }
+
+   /* quick out if its zero */
+   if (mp_iszero(a) == MP_YES) {
+      *str++ = '0';
+      *str = '\0';
+      return MP_OKAY;
+   }
+
+   if ((res = mp_init_copy(&t, a)) != MP_OKAY) {
+      return res;
+   }
+
+   /* if it is negative output a - */
+   if (t.sign == MP_NEG) {
+      /* we have to reverse our digits later... but not the - sign!! */
+      ++_s;
+
+      /* store the flag and mark the number as positive */
+      *str++ = '-';
+      t.sign = MP_ZPOS;
+
+      /* subtract a char */
+      --maxlen;
+   }
+
+   digs = 0;
+   while (mp_iszero(&t) == MP_NO) {
+      if (--maxlen < 1) {
+         /* no more room */
+         break;
+      }
+      if ((res = mp_div_d(&t, (mp_digit)radix, &t, &d)) != MP_OKAY) {
+         mp_clear(&t);
+         return res;
+      }
+      *str++ = mp_s_rmap[d];
+      ++digs;
+   }
+
+   /* reverse the digits of the string.  In this case _s points
+    * to the first digit [exluding the sign] of the number
+    */
+   bn_reverse((unsigned char *)_s, digs);
+
+   /* append a NULL so the string is properly terminated */
+   *str = '\0';
+
+   mp_clear(&t);
+   return MP_OKAY;
+}
+
+#endif
+
+/* ref:         HEAD -> master, tag: v1.1.0 */
+/* git commit:  08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
+/* commit time: 2019-01-28 20:32:32 +0100 */