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view libtommath/bn_mp_reduce_2k_setup.c @ 1885:5d8dbb6fdab7

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Fix SSH_PUBKEYINFO, limit characters, add tests We fix a bad_bufptr() failure from a previous commit. We now limit the allowed characters to those that will definitely be safe in a shell. Some scripts/programs may use arbitrary environment variables without escaping correctly - that could be a problem in a restricted environment. The current allowed set is a-z A-Z 0-9 .,_-+@ This also adds a test for SSH_PUBKEYINFO, by default it only runs under github actions (or "act -j build").
author Matt Johnston <matt@ucc.asn.au>
date Wed, 16 Mar 2022 17:17:23 +0800
parents 1051e4eea25a
children
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#include "tommath_private.h"
#ifdef BN_MP_REDUCE_2K_SETUP_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */

/* determines the setup value */
mp_err mp_reduce_2k_setup(const mp_int *a, mp_digit *d)
{
   mp_err err;
   mp_int tmp;
   int    p;

   if ((err = mp_init(&tmp)) != MP_OKAY) {
      return err;
   }

   p = mp_count_bits(a);
   if ((err = mp_2expt(&tmp, p)) != MP_OKAY) {
      mp_clear(&tmp);
      return err;
   }

   if ((err = s_mp_sub(&tmp, a, &tmp)) != MP_OKAY) {
      mp_clear(&tmp);
      return err;
   }

   *d = tmp.dp[0];
   mp_clear(&tmp);
   return MP_OKAY;
}
#endif