trunk/PTD/wptWipeFile.cpp

/* wptWipeFile.cpp - Secure file removal
 *      Copyright (C) 2001-2005 Timo Schulz
 *      Copyright (C) 2000 Matt Gauthier
 *
 * WinPT 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.
 *
 * WinPT 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 WinPT; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 *
 **************************************************************************
 * This code based on the sunlink.c file from the SRM project, but        *
 * it was heavily modified to work with W32 and with added GCRYPT         *
 * support for gathering random bytes.                                    *
 *                                                                        *
 * The original code was placed under the GNU Lesser Public License,      *
 * even so I decide to put this file under the GNU General Public License.*
 **************************************************************************
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <windows.h>
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <string.h>
#include <ctype.h>
#include <direct.h>

#include "openpgp.h"
#include "wptW32API.h"
#include "wptErrors.h"
#include "wptTypes.h"
#include "wptCrypto.h"

typedef unsigned __int64 DDWORD;

typedef struct {
    HANDLE fd;
    DDWORD filesize;
    DDWORD offset;
    BYTE  *buffer;
    DWORD  buffsize;
    const char *name;
    int    n_passes;
} wipe_context_s;


void (*progress_cb) (void *, DDWORD, DDWORD);
static void *progress_cb_value = NULL;

void (*unlink_cb)(void *, const char *, int, int, int) = NULL;
static void *unlink_cb_value = NULL;

/* Use the file handle in the context to overwrite a file
   with prepared buffer contents. */
static void 
overwrite (wipe_context_s *ctx)
{
    DDWORD blocks = 0, mod = 0;
    DWORD nwritten = 0;
    LONG size_high = 0;

    blocks = ctx->filesize / ctx->buffsize;
    mod = ctx->filesize % ctx->buffsize;
    SetFilePointer (ctx->fd, 0, &size_high, FILE_BEGIN);
    while (blocks--) {
        if (!WriteFile (ctx->fd, ctx->buffer, ctx->buffsize, &nwritten, NULL))
            break;
        ctx->offset += nwritten;
        if (unlink_cb)
            unlink_cb (unlink_cb_value, ctx->name, 0, (unsigned)ctx->offset, 
                       (unsigned)ctx->filesize*ctx->n_passes);
    }
    if (mod) {
        WriteFile (ctx->fd, ctx->buffer, (DWORD)mod, &nwritten, NULL);
        ctx->offset += nwritten;
        if (unlink_cb)
            unlink_cb (unlink_cb_value, ctx->name, 0, (unsigned)ctx->offset, 
                       (unsigned)ctx->filesize*ctx->n_passes);
    }
    FlushFileBuffers (ctx->fd);
    SetFilePointer (ctx->fd, 0, &size_high, FILE_BEGIN);
}


/* fill the buffer with random of the given level. */
static void
randomize_buffer (byte *buf, size_t bufsize, int level)
{
    const int blocksize = 512;
    int blocks = bufsize / blocksize;
    int mod = bufsize % blocksize;
    
    while (blocks--) {
        gpg_randomize (buf, blocksize, level);
        buf += blocksize;
    }
    if (mod)
        gpg_randomize (buf, mod, level);
}


/* performs a random overwrite. */
static void
overwrite_random (int npasses, wipe_context_s * ctx) 
{       
    int i;
    
    for (i = 0; i < npasses; i++) {
        randomize_buffer (ctx->buffer, ctx->buffsize, 0);
        overwrite (ctx);
    }
}


/* perform an overwrite with a specific byte (like 0x00). */
static void 
overwrite_byte (int byte, wipe_context_s * ctx) 
{
    memset (ctx->buffer, byte, ctx->buffsize);
    overwrite (ctx);
} /* overwrite_byte */


/* perform an overwrite with a specific byte triple (like 0x00, 0xFF, 0xAA). */
static void
overwrite_bytes (int byte1, int byte2, int byte3, wipe_context_s * ctx)
{
    DWORD i;

    memset (ctx->buffer, byte1, ctx->buffsize);
    for (i = 1; i < ctx->buffsize; i += 3) {
        ctx->buffer[i] = byte2;
        ctx->buffer[i+1] = byte3;
    }
    overwrite (ctx);
} /* overwrite_bytes */


/* For the case the file is not a regular file (this is true for
   devices or directories) this function tries to rename the file
   to random pattern and then it will be delete (without random!). */
extern "C" int 
rename_unlink (const char *path)
{
    struct stat statbuf;
    char *new_name = NULL, *p = NULL, c;  
    int i = 0, rc = 0;
    int is_dir = 0;

    if (GetFileAttributes (path) & FILE_ATTRIBUTE_DIRECTORY)
        is_dir = 1;
    
    new_name = new char[strlen (path)+15];
    if (!new_name)
        BUG (0);
    
    strcpy (new_name, path);
    p = strrchr (new_name, '\\');
    if (p != NULL) {
        p++;
        *p = '\0';
    } 
    else
        p = new_name;
    do {
        while (i < 14) {
            c = gpg_random_char (1);
            *p = c; 
            p++;
            i++;
        }
        *p = '\0';
    } while (stat (new_name, &statbuf) == 0);
    
    if (rename (path, new_name) == -1) {
        rc = WPTERR_FILE_READ;
        goto leave;
    }
    if (is_dir && RemoveDirectory (new_name) == FALSE)
        rc = WPTERR_FILE_REMOVE;
    else if (!DeleteFile (new_name))
        rc = WPTERR_FILE_REMOVE;
    
leave:
    free_if_alloc (new_name);
    return rc;
}


/* return the filesize as an 64-bit integer. */
static __int64
GetFileSize64 (const char * path)
{
    FILE *fp = fopen (path, "r");
    if (fp) {
        struct _stati64 statbuf;
        if (_fstati64 (fileno (fp), &statbuf) == -1)
            return -1;
        fclose (fp);
        return statbuf.st_size;
    }
    return -1;
}


static int
_secure_unlink (const char * path, int mode, HANDLE *r_fd)
{
    wipe_context_s ctx;
    LONG size_high = 0;
    
    if (GetFileAttributes (path) & FILE_ATTRIBUTE_DIRECTORY)
        return rename_unlink (path);
    
    memset (&ctx, 0, sizeof (ctx));
    ctx.name = path;
    ctx.buffsize = 16384;
    ctx.buffer = new byte[ctx.buffsize];
    if (!ctx.buffer)
        BUG (0);
    
    ctx.filesize = GetFileSize64 (path);
    if (!ctx.filesize) {
        free_if_alloc (ctx.buffer);
        unlink (path);
        return 0;
    }

    ctx.fd = CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL,
                         OPEN_ALWAYS, 0, NULL);
    if (ctx.fd == INVALID_HANDLE_VALUE) {
        free_if_alloc (ctx.buffer);
        return WPTERR_FILE_OPEN;
    }
    else if (r_fd)
        *r_fd = ctx.fd;
    
    gpg_quick_random_gen (1);
    if (unlink_cb)
        unlink_cb (unlink_cb_value, ctx.name, 0, 0, 0);

    switch (mode) {
    case WIPE_MODE_FAST:
        ctx.n_passes = 1;
        overwrite_random (1, &ctx);
        break;

    case WIPE_MODE_SIMPLE:
        ctx.n_passes = 2;
        overwrite_random (2, &ctx);
        break;
        
    case WIPE_MODE_DOD:
        ctx.n_passes = 5;
        overwrite_random (1, &ctx);
        overwrite_byte ((~1) & 0xFF, &ctx);
        overwrite_random (1, &ctx);
        overwrite_byte ((~4) & 0xFF, &ctx);
        overwrite_random (1, &ctx);
        break;
        
    case WIPE_MODE_GUTMANN:
        ctx.n_passes = 39;
        overwrite_random (4, &ctx);
        overwrite_byte( 0x55, &ctx );
        overwrite_byte ( 0xAA, &ctx );
        overwrite_bytes( 0x92, 0x49, 0x24, &ctx );
        overwrite_bytes( 0x49, 0x24, 0x92, &ctx );
        overwrite_bytes( 0x24, 0x92, 0x49, &ctx );
        overwrite_byte( 0x00, &ctx );
        overwrite_byte( 0x11, &ctx );
        overwrite_byte( 0x22, &ctx );
        overwrite_byte( 0x33, &ctx );
        overwrite_byte( 0x44, &ctx );
        overwrite_byte( 0x55, &ctx );
        overwrite_byte( 0x66, &ctx );
        overwrite_byte( 0x77, &ctx );
        overwrite_byte( 0x88, &ctx );
        overwrite_byte( 0x99, &ctx );
        overwrite_byte( 0xAA, &ctx );
        overwrite_byte( 0xBB, &ctx );
        overwrite_byte( 0xCC, &ctx );
        overwrite_byte( 0xDD, &ctx );
        overwrite_byte( 0xEE, &ctx );
        overwrite_byte( 0xFF, &ctx );
        overwrite_bytes( 0x92, 0x49, 0x24, &ctx );
        overwrite_bytes( 0x49, 0x24, 0x92, &ctx );
        overwrite_bytes( 0x24, 0x92, 0x49, &ctx );
        overwrite_bytes( 0x6D, 0xB6, 0xDB, &ctx );
        overwrite_bytes( 0xB6, 0xDB, 0x6D, &ctx );
        overwrite_bytes( 0xDB, 0x6D, 0xB6, &ctx );
        overwrite_random( 4, &ctx );
        break;
    }
        
    /* Set file length to zero so allocated clusters cannot be trailed */       
    SetFilePointer (ctx.fd, 0, &size_high, FILE_BEGIN);
    SetEndOfFile (ctx.fd);
    CloseHandle (ctx.fd);
    
    memset (ctx.buffer, 0, ctx.buffsize); /* burn the last evidence */  
    free_if_alloc (ctx.buffer);

    return rename_unlink (path);
}


/* Delete a file in a secure way with the given mode. */
extern "C" int 
secure_unlink (const char *path, int mode)
{
    return _secure_unlink (path, mode, NULL);
}


/* Set the callback @cb for the wipe function. The callback is call every time
   the wipe function writes data to the file. */
extern "C" void
secure_unlink_set_cb (void (*cb)(void *, const char *, int, int, int), 
                      void *cb_value)
{
    unlink_cb = cb;
    unlink_cb_value = cb_value;
}


/* wipe all free space of the given drive by creating a temp file
   which has the size of the free space. This file will be then
   overwritten with random and static pattern. */
extern "C" int
wipe_freespace (const char * drive, HANDLE *r_fd,
                void (*cb)(void *, DDWORD, DDWORD), void * cb_value)
{
    ULARGE_INTEGER caller, total, frees;
    LONG hpart=0;
    HANDLE fd;
    int disktyp = GetDriveType (drive);
    int rc;
    char * file;

    if (disktyp != DRIVE_FIXED && disktyp != DRIVE_REMOVABLE)
        return -1;
    if (!GetDiskFreeSpaceEx (drive, &caller, &total, &frees))
        return -1;   

    /* disk is full */
    if (!frees.LowPart)
        return 0;
    file = new char[strlen (drive)+8];
    if (!file)
        BUG (0);
    sprintf (file, "%stemp_winpt.tmp", drive);
    fd = CreateFile (file,
                    GENERIC_READ|GENERIC_WRITE,
                    FILE_SHARE_READ|FILE_SHARE_WRITE,
                    NULL, CREATE_ALWAYS, 0, NULL);
    if (fd == INVALID_HANDLE_VALUE) {
        free_if_alloc (file);
        return WPTERR_FILE_OPEN;
    }
    hpart = frees.HighPart;
    SetFilePointer (fd, frees.LowPart, &hpart, FILE_BEGIN);
    SetEndOfFile (fd);
    CloseHandle (fd);

    if (cb && cb_value) {
        progress_cb = cb;
        progress_cb_value = cb_value;
    }
    rc = _secure_unlink (file, WIPE_MODE_FAST, r_fd);
    free_if_alloc (file);
    return rc;
}
1	werner	46	/* wptWipeFile.cpp - Secure file removal
2			* Copyright (C) 2001-2005 Timo Schulz
3			* Copyright (C) 2000 Matt Gauthier
4			*
5			* WinPT software; you can redistribute it and/or modify
6			* it under the terms of the GNU General Public License as published by
7			* the Free Software Foundation; either version 2 of the License, or
8			* (at your option) any later version.
9			*
10			* WinPT is distributed in the hope that it will be useful,
11			* but WITHOUT ANY WARRANTY; without even the implied warranty of
12			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13			* GNU General Public License for more details.
14			*
15			* You should have received a copy of the GNU General Public License
16			* along with WinPT; if not, write to the Free Software
17			* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
18			*
19			**************************************************************************
20			* This code based on the sunlink.c file from the SRM project, but *
21			* it was heavily modified to work with W32 and with added GCRYPT *
22			* support for gathering random bytes. *
23			* *
24			* The original code was placed under the GNU Lesser Public License, *
25			* even so I decide to put this file under the GNU General Public License.*
26			**************************************************************************
27			*/
28
29			#ifdef HAVE_CONFIG_H
30			#include <config.h>
31			#endif
32
33			#include <windows.h>
34			#include <windows.h>
35			#include <stdio.h>
36			#include <stdlib.h>
37			#include <sys/stat.h>
38			#include <string.h>
39			#include <ctype.h>
40			#include <direct.h>
41
42			#include "openpgp.h"
43			#include "wptW32API.h"
44			#include "wptErrors.h"
45			#include "wptTypes.h"
46			#include "wptCrypto.h"
47
48			typedef unsigned __int64 DDWORD;
49
50			typedef struct {
51			HANDLE fd;
52			DDWORD filesize;
53			DDWORD offset;
54			BYTE *buffer;
55			DWORD buffsize;
56			const char *name;
57			int n_passes;
58			} wipe_context_s;
59
60
61			void (progress_cb) (void , DDWORD, DDWORD);
62			static void *progress_cb_value = NULL;
63
64			void (unlink_cb)(void , const char *, int, int, int) = NULL;
65			static void *unlink_cb_value = NULL;
66
67			/* Use the file handle in the context to overwrite a file
68			with prepared buffer contents. */
69			static void
70			overwrite (wipe_context_s *ctx)
71			{
72			DDWORD blocks = 0, mod = 0;
73			DWORD nwritten = 0;
74			LONG size_high = 0;
75
76			blocks = ctx->filesize / ctx->buffsize;
77			mod = ctx->filesize % ctx->buffsize;
78			SetFilePointer (ctx->fd, 0, &size_high, FILE_BEGIN);
79			while (blocks--) {
80			if (!WriteFile (ctx->fd, ctx->buffer, ctx->buffsize, &nwritten, NULL))
81			break;
82			ctx->offset += nwritten;
83			if (unlink_cb)
84			unlink_cb (unlink_cb_value, ctx->name, 0, (unsigned)ctx->offset,
85			(unsigned)ctx->filesize*ctx->n_passes);
86			}
87			if (mod) {
88			WriteFile (ctx->fd, ctx->buffer, (DWORD)mod, &nwritten, NULL);
89			ctx->offset += nwritten;
90			if (unlink_cb)
91			unlink_cb (unlink_cb_value, ctx->name, 0, (unsigned)ctx->offset,
92			(unsigned)ctx->filesize*ctx->n_passes);
93			}
94			FlushFileBuffers (ctx->fd);
95			SetFilePointer (ctx->fd, 0, &size_high, FILE_BEGIN);
96			}
97
98
99			/* fill the buffer with random of the given level. */
100			static void
101			randomize_buffer (byte *buf, size_t bufsize, int level)
102			{
103			const int blocksize = 512;
104			int blocks = bufsize / blocksize;
105			int mod = bufsize % blocksize;
106
107			while (blocks--) {
108			gpg_randomize (buf, blocksize, level);
109			buf += blocksize;
110			}
111			if (mod)
112			gpg_randomize (buf, mod, level);
113			}
114
115
116			/* performs a random overwrite. */
117			static void
118			overwrite_random (int npasses, wipe_context_s * ctx)
119			{
120			int i;
121
122			for (i = 0; i < npasses; i++) {
123			randomize_buffer (ctx->buffer, ctx->buffsize, 0);
124			overwrite (ctx);
125			}
126			}
127
128
129			/* perform an overwrite with a specific byte (like 0x00). */
130			static void
131			overwrite_byte (int byte, wipe_context_s * ctx)
132			{
133			memset (ctx->buffer, byte, ctx->buffsize);
134			overwrite (ctx);
135			} /* overwrite_byte */
136
137
138			/* perform an overwrite with a specific byte triple (like 0x00, 0xFF, 0xAA). */
139			static void
140			overwrite_bytes (int byte1, int byte2, int byte3, wipe_context_s * ctx)
141			{
142			DWORD i;
143
144			memset (ctx->buffer, byte1, ctx->buffsize);
145			for (i = 1; i < ctx->buffsize; i += 3) {
146			ctx->buffer[i] = byte2;
147			ctx->buffer[i+1] = byte3;
148			}
149			overwrite (ctx);
150			} /* overwrite_bytes */
151
152
153			/* For the case the file is not a regular file (this is true for
154			devices or directories) this function tries to rename the file
155			to random pattern and then it will be delete (without random!). */
156			extern "C" int
157			rename_unlink (const char *path)
158			{
159			struct stat statbuf;
160			char new_name = NULL, p = NULL, c;
161			int i = 0, rc = 0;
162			int is_dir = 0;
163
164			if (GetFileAttributes (path) & FILE_ATTRIBUTE_DIRECTORY)
165			is_dir = 1;
166
167			new_name = new char[strlen (path)+15];
168			if (!new_name)
169			BUG (0);
170
171			strcpy (new_name, path);
172			p = strrchr (new_name, '\\');
173			if (p != NULL) {
174			p++;
175			*p = '\0';
176			}
177			else
178			p = new_name;
179			do {
180			while (i < 14) {
181			c = gpg_random_char (1);
182			*p = c;
183			p++;
184			i++;
185			}
186			*p = '\0';
187			} while (stat (new_name, &statbuf) == 0);
188
189			if (rename (path, new_name) == -1) {
190			rc = WPTERR_FILE_READ;
191			goto leave;
192			}
193			if (is_dir && RemoveDirectory (new_name) == FALSE)
194			rc = WPTERR_FILE_REMOVE;
195			else if (!DeleteFile (new_name))
196			rc = WPTERR_FILE_REMOVE;
197
198			leave:
199			free_if_alloc (new_name);
200			return rc;
201			}
202
203
204			/* return the filesize as an 64-bit integer. */
205			static __int64
206			GetFileSize64 (const char * path)
207			{
208			FILE *fp = fopen (path, "r");
209			if (fp) {
210			struct _stati64 statbuf;
211			if (_fstati64 (fileno (fp), &statbuf) == -1)
212			return -1;
213			fclose (fp);
214			return statbuf.st_size;
215			}
216			return -1;
217			}
218
219
220			static int
221			_secure_unlink (const char * path, int mode, HANDLE *r_fd)
222			{
223			wipe_context_s ctx;
224			LONG size_high = 0;
225
226			if (GetFileAttributes (path) & FILE_ATTRIBUTE_DIRECTORY)
227			return rename_unlink (path);
228
229			memset (&ctx, 0, sizeof (ctx));
230			ctx.name = path;
231			ctx.buffsize = 16384;
232			ctx.buffer = new byte[ctx.buffsize];
233			if (!ctx.buffer)
234			BUG (0);
235
236			ctx.filesize = GetFileSize64 (path);
237			if (!ctx.filesize) {
238			free_if_alloc (ctx.buffer);
239			unlink (path);
240			return 0;
241			}
242
243			ctx.fd = CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL,
244			OPEN_ALWAYS, 0, NULL);
245			if (ctx.fd == INVALID_HANDLE_VALUE) {
246			free_if_alloc (ctx.buffer);
247			return WPTERR_FILE_OPEN;
248			}
249			else if (r_fd)
250			*r_fd = ctx.fd;
251
252			gpg_quick_random_gen (1);
253			if (unlink_cb)
254			unlink_cb (unlink_cb_value, ctx.name, 0, 0, 0);
255
256			switch (mode) {
257			case WIPE_MODE_FAST:
258			ctx.n_passes = 1;
259			overwrite_random (1, &ctx);
260			break;
261
262			case WIPE_MODE_SIMPLE:
263			ctx.n_passes = 2;
264			overwrite_random (2, &ctx);
265			break;
266
267			case WIPE_MODE_DOD:
268			ctx.n_passes = 5;
269			overwrite_random (1, &ctx);
270			overwrite_byte ((~1) & 0xFF, &ctx);
271			overwrite_random (1, &ctx);
272			overwrite_byte ((~4) & 0xFF, &ctx);
273			overwrite_random (1, &ctx);
274			break;
275
276			case WIPE_MODE_GUTMANN:
277			ctx.n_passes = 39;
278			overwrite_random (4, &ctx);
279			overwrite_byte( 0x55, &ctx );
280			overwrite_byte ( 0xAA, &ctx );
281			overwrite_bytes( 0x92, 0x49, 0x24, &ctx );
282			overwrite_bytes( 0x49, 0x24, 0x92, &ctx );
283			overwrite_bytes( 0x24, 0x92, 0x49, &ctx );
284			overwrite_byte( 0x00, &ctx );
285			overwrite_byte( 0x11, &ctx );
286			overwrite_byte( 0x22, &ctx );
287			overwrite_byte( 0x33, &ctx );
288			overwrite_byte( 0x44, &ctx );
289			overwrite_byte( 0x55, &ctx );
290			overwrite_byte( 0x66, &ctx );
291			overwrite_byte( 0x77, &ctx );
292			overwrite_byte( 0x88, &ctx );
293			overwrite_byte( 0x99, &ctx );
294			overwrite_byte( 0xAA, &ctx );
295			overwrite_byte( 0xBB, &ctx );
296			overwrite_byte( 0xCC, &ctx );
297			overwrite_byte( 0xDD, &ctx );
298			overwrite_byte( 0xEE, &ctx );
299			overwrite_byte( 0xFF, &ctx );
300			overwrite_bytes( 0x92, 0x49, 0x24, &ctx );
301			overwrite_bytes( 0x49, 0x24, 0x92, &ctx );
302			overwrite_bytes( 0x24, 0x92, 0x49, &ctx );
303			overwrite_bytes( 0x6D, 0xB6, 0xDB, &ctx );
304			overwrite_bytes( 0xB6, 0xDB, 0x6D, &ctx );
305			overwrite_bytes( 0xDB, 0x6D, 0xB6, &ctx );
306			overwrite_random( 4, &ctx );
307			break;
308			}
309
310			/* Set file length to zero so allocated clusters cannot be trailed */
311			SetFilePointer (ctx.fd, 0, &size_high, FILE_BEGIN);
312			SetEndOfFile (ctx.fd);
313			CloseHandle (ctx.fd);
314
315			memset (ctx.buffer, 0, ctx.buffsize); /* burn the last evidence */
316			free_if_alloc (ctx.buffer);
317
318			return rename_unlink (path);
319			}
320
321
322			/* Delete a file in a secure way with the given mode. */
323			extern "C" int
324			secure_unlink (const char *path, int mode)
325			{
326			return _secure_unlink (path, mode, NULL);
327			}
328
329
330			/* Set the callback @cb for the wipe function. The callback is call every time
331			the wipe function writes data to the file. */
332			extern "C" void
333			secure_unlink_set_cb (void (cb)(void , const char *, int, int, int),
334			void *cb_value)
335			{
336			unlink_cb = cb;
337			unlink_cb_value = cb_value;
338			}
339
340
341			/* wipe all free space of the given drive by creating a temp file
342			which has the size of the free space. This file will be then
343			overwritten with random and static pattern. */
344			extern "C" int
345			wipe_freespace (const char * drive, HANDLE *r_fd,
346			void (cb)(void , DDWORD, DDWORD), void * cb_value)
347			{
348			ULARGE_INTEGER caller, total, frees;
349			LONG hpart=0;
350			HANDLE fd;
351			int disktyp = GetDriveType (drive);
352			int rc;
353			char * file;
354
355			if (disktyp != DRIVE_FIXED && disktyp != DRIVE_REMOVABLE)
356			return -1;
357			if (!GetDiskFreeSpaceEx (drive, &caller, &total, &frees))
358			return -1;
359
360			/* disk is full */
361			if (!frees.LowPart)
362			return 0;
363			file = new char[strlen (drive)+8];
364			if (!file)
365			BUG (0);
366			sprintf (file, "%stemp_winpt.tmp", drive);
367			fd = CreateFile (file,
368			GENERIC_READ\|GENERIC_WRITE,
369			FILE_SHARE_READ\|FILE_SHARE_WRITE,
370			NULL, CREATE_ALWAYS, 0, NULL);
371			if (fd == INVALID_HANDLE_VALUE) {
372			free_if_alloc (file);
373			return WPTERR_FILE_OPEN;
374			}
375			hpart = frees.HighPart;
376			SetFilePointer (fd, frees.LowPart, &hpart, FILE_BEGIN);
377			SetEndOfFile (fd);
378			CloseHandle (fd);
379
380			if (cb && cb_value) {
381			progress_cb = cb;
382			progress_cb_value = cb_value;
383			}
384			rc = _secure_unlink (file, WIPE_MODE_FAST, r_fd);
385			free_if_alloc (file);
386			return rc;
387			}