view libtommath/bn_mp_toradix_n.c @ 1665:7c17995bcdfb

Improve address logging on early exit messages (#83) Change 'Early exit' and 'Exit before auth' messages to include the IP address & port as part of the message. This allows log scanning utilities such as 'fail2ban' to obtain the offending IP address as part of the failure event instead of extracting the PID from the message and then scanning the log again for match 'child connection from' messages Signed-off-by: Kevin Darbyshire-Bryant <[email protected]>
author Kevin Darbyshire-Bryant <6500011+ldir-EDB0@users.noreply.github.com>
date Wed, 18 Mar 2020 15:28:56 +0000
parents f52919ffd3b1
children
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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 */