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gnupg/kbx/keybox-util.c
Werner Koch 48a2c93a18
gpg,gpgsm: Block signals during keyring/keybox update.
* kbx/keybox-util.c (keybox_file_rename): Add arg BLOCK_SIGNALS.
* kbx/keybox-update.c (rename_tmp_file): Block all signals when doing
a double rename.
* g10/keyring.c (rename_tmp_file): Block all signals during the double
rename.
--

This might fix
Debian-bug-id: 831510

Signed-off-by: Werner Koch <wk@gnupg.org>
2016-08-03 15:31:27 +02:00

220 lines
6.2 KiB
C

/* keybox-util.c - Utility functions for Keybox
* Copyright (C) 2001 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifdef HAVE_DOSISH_SYSTEM
# define WIN32_LEAN_AND_MEAN /* We only need the OS core stuff. */
# include <windows.h>
#endif
#include "keybox-defs.h"
#include "utilproto.h"
static void *(*alloc_func)(size_t n) = malloc;
static void *(*realloc_func)(void *p, size_t n) = realloc;
static void (*free_func)(void*) = free;
void
keybox_set_malloc_hooks ( void *(*new_alloc_func)(size_t n),
void *(*new_realloc_func)(void *p, size_t n),
void (*new_free_func)(void*) )
{
alloc_func = new_alloc_func;
realloc_func = new_realloc_func;
free_func = new_free_func;
}
void *
_keybox_malloc (size_t n)
{
return alloc_func (n);
}
void *
_keybox_realloc (void *a, size_t n)
{
return realloc_func (a, n);
}
void *
_keybox_calloc (size_t n, size_t m)
{
void *p = _keybox_malloc (n*m);
if (p)
memset (p, 0, n* m);
return p;
}
void
_keybox_free (void *p)
{
if (p)
free_func (p);
}
/* Store the two malloced temporary file names used for keybox updates
of file FILENAME at R_BAKNAME and R_TMPNAME. On error an error
code is returned and NULL stored at R_BAKNAME and R_TMPNAME. If
FOR_KEYRING is true the returned names match those used by GnuPG's
keyring code. */
gpg_error_t
keybox_tmp_names (const char *filename, int for_keyring,
char **r_bakname, char **r_tmpname)
{
gpg_error_t err;
char *bak_name, *tmp_name;
*r_bakname = NULL;
*r_tmpname = NULL;
# ifdef USE_ONLY_8DOT3
/* Here is another Windoze bug?:
* you can't rename("pubring.kbx.tmp", "pubring.kbx");
* but rename("pubring.kbx.tmp", "pubring.aaa");
* works. So we replace ".kbx" by ".kb_" or ".k__". Note that we
* can't use ".bak" and ".tmp", because these suffixes are used by
* gpg's keyrings and would lead to a sharing violation or data
* corruption. If the name does not end in ".kbx" we assume working
* on a modern file system and append the suffix. */
{
const char *ext = for_keyring? EXTSEP_S GPGEXT_GPG : EXTSEP_S "kbx";
const char *b_ext = for_keyring? EXTSEP_S "bak" : EXTSEP_S "kb_";
const char *t_ext = for_keyring? EXTSEP_S "tmp" : EXTSEP_S "k__";
int repl;
if (strlen (ext) != 4 || strlen (b_ext) != 4)
BUG ();
repl = (strlen (filename) > 4
&& !strcmp (filename + strlen (filename) - 4, ext));
bak_name = xtrymalloc (strlen (filename) + (repl?0:4) + 1);
if (!bak_name)
return gpg_error_from_syserror ();
strcpy (bak_name, filename);
strcpy (bak_name + strlen (filename) - (repl?4:0), b_ext);
tmp_name = xtrymalloc (strlen (filename) + (repl?0:4) + 1);
if (!tmp_name)
{
err = gpg_error_from_syserror ();
xfree (bak_name);
return err;
}
strcpy (tmp_name, filename);
strcpy (tmp_name + strlen (filename) - (repl?4:0), t_ext);
}
# else /* Posix file names */
(void)for_keyring;
bak_name = xtrymalloc (strlen (filename) + 2);
if (!bak_name)
return gpg_error_from_syserror ();
strcpy (stpcpy (bak_name, filename), "~");
tmp_name = xtrymalloc (strlen (filename) + 5);
if (!tmp_name)
{
err = gpg_error_from_syserror ();
xfree (bak_name);
return err;
}
strcpy (stpcpy (tmp_name,filename), EXTSEP_S "tmp");
# endif /* Posix filename */
*r_bakname = bak_name;
*r_tmpname = tmp_name;
return 0;
}
/* Wrapper for rename(2) to handle Windows peculiarities. If
* BLOCK_SIGNALS is not NULL and points to a variable set to true, all
* signals will be blocked by calling gnupg_block_all_signals; the
* caller needs to call gnupg_unblock_all_signals if that variable is
* still set to true on return. */
gpg_error_t
keybox_file_rename (const char *oldname, const char *newname,
int *block_signals)
{
gpg_error_t err = 0;
if (block_signals && *block_signals)
gnupg_block_all_signals ();
#ifdef HAVE_DOSISH_SYSTEM
{
int wtime = 0;
gnupg_remove (newname);
again:
if (rename (oldname, newname))
{
if (GetLastError () == ERROR_SHARING_VIOLATION)
{
/* Another process has the file open. We do not use a
* lock for read but instead we wait until the other
* process has closed the file. This may take long but
* that would also be the case with a dotlock approach for
* read and write. Note that we don't need this on Unix
* due to the inode concept.
*
* So let's wait until the rename has worked. The retry
* intervals are 50, 100, 200, 400, 800, 50ms, ... */
if (!wtime || wtime >= 800)
wtime = 50;
else
wtime *= 2;
if (wtime >= 800)
log_info ("waiting for file '%s' to become accessible ...\n",
oldname);
Sleep (wtime);
goto again;
}
err = gpg_error_from_syserror ();
}
}
#else /* Unix */
{
#ifdef __riscos__
gnupg_remove (newname);
#endif
if (rename (oldname, newname) )
err = gpg_error_from_syserror ();
}
#endif /* Unix */
if (block_signals && *block_signals && err)
{
gnupg_unblock_all_signals ();
*block_signals = 0;
}
if (err)
log_error ("renaming '%s' to '%s' failed: %s\n",
oldname, newname, gpg_strerror (err));
return err;
}