scyther/src/tempfile.c
2020-10-28 15:19:47 +01:00

141 lines
3.1 KiB
C

/*
* Scyther : An automatic verifier for security protocols.
* Copyright (C) 2007-2020 Cas Cremers
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/**
*
* @file tempfile.c
*
* Generate a temporary file stream
*
* Before Vista this was trivial, more or less. However Vista restricts access
* so much that this call usually breaks, which is a pretty annoying bug.
*/
#include <stdio.h>
#include <stdlib.h>
#ifdef FORWINDOWS
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <io.h>
#endif
#include "bool.h"
#include "symbol.h"
#include "error.h"
//! Create a new temporary file and return the pointer.
/**
* Before Vista this was trivial, more or less. However Vista restricts access
* so much that this call usually breaks, which is a pretty annoying bug.
*
* See e.g., http://msdn2.microsoft.com/en-us/library/aa363875.aspx
*/
#ifdef FORWINDOWS
/*
* tmpfile() replacement for Windows Vista (and later?)
*/
FILE *
win32_tmpfile (void)
{
DWORD pathlength;
WCHAR path[MAX_PATH + 1];
pathlength = GetTempPathW (MAX_PATH, path);
if ((pathlength > 0) && (pathlength < MAX_PATH))
{
WCHAR filename[MAX_PATH + 1];
if (GetTempFileNameW (path, L"scyther_", 0, filename) != 0)
{
HANDLE handle;
handle = CreateFileW (filename,
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL |
FILE_FLAG_DELETE_ON_CLOSE, NULL);
if (handle != INVALID_HANDLE_VALUE)
{
int fd;
fd = _open_osfhandle ((intptr_t) handle, 0);
if (fd < 0)
{
CloseHandle (handle);
}
else
{
FILE *fp;
fp = fdopen (fd, "w+b");
if (fp == NULL)
{
_close (fd);
}
else
{
// Return a real filepointer
return fp;
}
}
}
else
{
DeleteFileW (filename);
}
}
}
return NULL;
}
#endif
//! Create a tempfile
/**
* Returns a filepointer to an open temporary file.
*
* Really, this should always work and the calling code should not be required
* to check for errors (such as fp=NULL). We therefore simply throw an error
* if the underlying code returns NULL.
*/
FILE *
scyther_tempfile (void)
{
FILE *fp;
#ifdef FORWINDOWS
/* Do special version because of M$ breaking tmpfile in Vista */
fp = win32_tmpfile ();
#else
/* On any other platform the normal stuff just works (tm) */
fp = tmpfile ();
#endif
if (fp == NULL)
{
error
("Attempt at creating a temporary file failed for unknown reasons.");
}
return fp;
}