lib/gstr.c

   1 /*
   2  *      Copyright (C) 2006 Free Software Foundation
   3  *      Copyright (C) 2002 Nikos Mavroyanopoulos
   4  *
   5  * This file is part of LIBTASN1.
   6  *
   7  * The LIBTASN1 library is free software; you can redistribute it
   8  * and/or modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301, USA
  21  */
  22
  23 #include <int.h>
  24
  25 /* These function are like strcat, strcpy. They only
  26  * do bounds checking (they shouldn't cause buffer overruns),
  27  * and they always produce null terminated strings.
  28  *
  29  * They should be used only with null terminated strings.
  30  */
  31 void
  32 _asn1_str_cat (char *dest, size_t dest_tot_size, const char *src)
  33 {
  34   size_t str_size = strlen (src);
  35   size_t dest_size = strlen (dest);
  36
  37   if (dest_tot_size - dest_size > str_size)
  38     {
  39       strcat (dest, src);
  40     }
  41   else
  42     {
  43       if (dest_tot_size - dest_size > 0)
  44         {
  45           strncat (dest, src, (dest_tot_size - dest_size) - 1);
  46           dest[dest_tot_size - 1] = 0;
  47         }
  48     }
  49 }
  50
  51 void
  52 _asn1_str_cpy (char *dest, size_t dest_tot_size, const char *src)
  53 {
  54   size_t str_size = strlen (src);
  55
  56   if (dest_tot_size > str_size)
  57     {
  58       strcpy (dest, src);
  59     }
  60   else
  61     {
  62       if (dest_tot_size > 0)
  63         {
  64           strncpy (dest, src, (dest_tot_size) - 1);
  65           dest[dest_tot_size - 1] = 0;
  66         }
  67     }
  68 }