lib/minitasn1/gstr.c

   1 /*
   2  * Copyright (C) 2002-2012 Free Software Foundation, Inc.
   3  *
   4  * This file is part of LIBTASN1.
   5  *
   6  * The LIBTASN1 library is free software; you can redistribute it
   7  * and/or modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19  * 02110-1301, USA
  20  */
  21
  22 #include <int.h>
  23 #include "gstr.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 /* Returns the bytes copied (not including the null terminator) */
  52 unsigned int
  53 _asn1_str_cpy (char *dest, size_t dest_tot_size, const char *src)
  54 {
  55   size_t str_size = strlen (src);
  56
  57   if (dest_tot_size > str_size)
  58     {
  59       strcpy (dest, src);
  60       return str_size;
  61     }
  62   else
  63     {
  64       if (dest_tot_size > 0)
  65         {
  66           str_size = dest_tot_size - 1;
  67           memcpy (dest, src, str_size);
  68           dest[str_size] = 0;
  69           return str_size;
  70         }
  71       else return 0;
  72     }
  73 }