view libtommath/bn_mp_from_sbin.c @ 1861:2b3a8026a6ce

Add re-exec for server This allows ASLR to re-randomize the address space for every connection, preventing some vulnerabilities from being exploitable by repeated probing. Overhead (memory and time) is yet to be confirmed. At present this is only enabled on Linux. Other BSD platforms with fexecve() would probably also work though have not been tested.
author Matt Johnston <matt@ucc.asn.au>
date Sun, 30 Jan 2022 10:14:56 +0800
parents 1051e4eea25a
children
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#include "tommath_private.h"
#ifdef BN_MP_FROM_SBIN_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */

/* read signed bin, big endian, first byte is 0==positive or 1==negative */
mp_err mp_from_sbin(mp_int *a, const unsigned char *buf, size_t size)
{
   mp_err err;

   /* read magnitude */
   if ((err = mp_from_ubin(a, buf + 1, size - 1u)) != MP_OKAY) {
      return err;
   }

   /* first byte is 0 for positive, non-zero for negative */
   if (buf[0] == (unsigned char)0) {
      a->sign = MP_ZPOS;
   } else {
      a->sign = MP_NEG;
   }

   return MP_OKAY;
}
#endif