lib/util/talloc_keep_secret.c

   1 /*
   2  * Copyright (c) 2019      Andreas Schneider <asn@samba.org>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "replace.h"
  19 #include <talloc.h>
  20 #include "lib/util/fault.h"
  21 #include "talloc_keep_secret.h"
  22
  23 static int talloc_keep_secret_destructor(void *ptr)
  24 {
  25         int ret;
  26         size_t size = talloc_get_size(ptr);
  27
  28         if (unlikely(size == 0)) {
  29                 return 0;
  30         }
  31
  32         ret = memset_s(ptr, size, 0, size);
  33         if (unlikely(ret != 0)) {
  34                 char *msg = NULL;
  35                 int ret2;
  36                 ret2 = asprintf(&msg,
  37                                 "talloc_keep_secret_destructor: memset_s() failed: %s",
  38                                 strerror(ret));
  39                 if (ret2 != -1) {
  40                         smb_panic(msg);
  41                 } else {
  42                         smb_panic("talloc_keep_secret_destructor: memset_s() failed");
  43                 }
  44         }
  45
  46         return 0;
  47 }
  48
  49 void _talloc_keep_secret(void *ptr, const char *name)
  50 {
  51         size_t size;
  52
  53         if (unlikely(ptr == NULL)) {
  54 #ifdef DEVELOPER
  55                 smb_panic("Invalid talloc pointer");
  56 #endif
  57                 return;
  58         }
  59
  60         size = talloc_get_size(ptr);
  61         if (unlikely(size == 0)) {
  62                 return;
  63         }
  64
  65         talloc_set_name_const(ptr, name);
  66         talloc_set_destructor(ptr, talloc_keep_secret_destructor);
  67 }