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.*
 **************************************************************************
 */

#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"


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, unsigned, unsigned) = NULL;
static void *unlink_cb_value = NULL;

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);
} /* overwrite */


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);
} /* randomize_buffer */


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);
    }
} /* overwrite_random */


static void 
overwrite_byte (int byte, wipe_context_s * ctx) 
{
    memset (ctx->buffer, byte, ctx->buffsize);
    overwrite (ctx);
} /* overwrite_byte */


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!). 
 **/
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;
} /* rename_unlink */


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


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);
        return WPTERR_FILE_ZERO;
    }

    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);
}

int 
secure_unlink (const char *path, int mode)
{
    return _secure_unlink (path, mode, NULL);
} /* secure_unlink */


void
secure_unlink_set_cb (void (*cb)(void *, const char *, int, unsigned, unsigned), 
                      void *cb_value)
{
    unlink_cb = cb;
    unlink_cb_value = cb_value;
} /* secure_unlink_set_cb */


/* Windows 98 - Q188074 */
#define REGISTRY_FILESYSTEM "System\\CurrentControlSet\\Control\\FileSystem"
#define REGISTRY_LOWDISKSPACE "DisableLowDiskSpaceBroadcast"


/* disables the annoying warning Windows 98 displays when disk space is low */
static void
handle_lowdiskspace_notify( const char * drive, int disable )
{    
    OSVERSIONINFO ov;
    HKEY key;
    DWORD n;

    memset( &ov, 0, sizeof ov );
    ov.dwOSVersionInfoSize = sizeof ov;
    GetVersionEx( &ov );
    if( ov.dwPlatformId == VER_PLATFORM_WIN32_NT )
        return;

    if( disable ) {
        unsigned newi = (1 << (toupper((unsigned)drive) - (unsigned)'A'));
        if( RegOpenKey( HKEY_LOCAL_MACHINE, REGISTRY_FILESYSTEM, &key ) ) {
            n = sizeof newi;
            RegSetValue( key, REGISTRY_LOWDISKSPACE, REG_DWORD, (LPCTSTR)newi, n );
            RegCloseKey( key );
        }
    }
    else {
        if( RegOpenKey( HKEY_LOCAL_MACHINE, REGISTRY_FILESYSTEM, &key ) ) {
            RegDeleteKey( key, REGISTRY_LOWDISKSPACE );
            RegCloseKey( key );
        }
    }
} /* handle_lowdiskspace_notify */


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;
    handle_lowdiskspace_notify (drive, 1);

    if (!frees.LowPart)
        return WPTERR_FILE_ZERO;
    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);

    handle_lowdiskspace_notify (drive, 0);
    free_if_alloc (file);
    return rc;
} /* wipe_freespace */
1	twoaday	2	/* 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			#include <windows.h>
30			#include <stdio.h>
31			#include <stdlib.h>
32			#include <sys/stat.h>
33			#include <string.h>
34			#include <ctype.h>
35			#include <direct.h>
36
37			#include "openpgp.h"
38			#include "wptW32API.h"
39			#include "wptErrors.h"
40			#include "wptTypes.h"
41
42
43			typedef unsigned __int64 DDWORD;
44
45			typedef struct {
46			HANDLE fd;
47			DDWORD filesize;
48			DDWORD offset;
49			BYTE *buffer;
50			DWORD buffsize;
51			const char *name;
52			int n_passes;
53			} wipe_context_s;
54
55
56			void (progress_cb) (void , DDWORD, DDWORD);
57			static void *progress_cb_value = NULL;
58
59			void (unlink_cb)(void , const char *, int, unsigned, unsigned) = NULL;
60			static void *unlink_cb_value = NULL;
61
62			static void
63			overwrite (wipe_context_s * ctx)
64			{
65			DDWORD blocks = 0, mod = 0;
66			DWORD nwritten = 0;
67			LONG size_high = 0;
68
69			blocks = ctx->filesize / ctx->buffsize;
70			mod = ctx->filesize % ctx->buffsize;
71			SetFilePointer (ctx->fd, 0, &size_high, FILE_BEGIN);
72			while (blocks--) {
73			if (!WriteFile (ctx->fd, ctx->buffer, ctx->buffsize, &nwritten, NULL))
74			break;
75			ctx->offset += nwritten;
76			if (unlink_cb)
77			unlink_cb (unlink_cb_value, ctx->name, 0, (unsigned)ctx->offset,
78			(unsigned)ctx->filesize*ctx->n_passes);
79			}
80			if (mod) {
81			WriteFile (ctx->fd, ctx->buffer, (DWORD)mod, &nwritten, NULL);
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			FlushFileBuffers (ctx->fd);
88			SetFilePointer (ctx->fd, 0, &size_high, FILE_BEGIN);
89			} /* overwrite */
90
91
92			static void
93			randomize_buffer (byte * buf, size_t bufsize, int level)
94			{
95			const int blocksize = 512;
96			int blocks = bufsize / blocksize;
97			int mod = bufsize % blocksize;
98
99			while (blocks--) {
100			gpg_randomize (buf, blocksize, level);
101			buf += blocksize;
102			}
103			if (mod)
104			gpg_randomize (buf, mod, level);
105			} /* randomize_buffer */
106
107
108			static void
109			overwrite_random (int npasses, wipe_context_s * ctx)
110			{
111			int i;
112
113			for (i = 0; i < npasses; i++) {
114			randomize_buffer (ctx->buffer, ctx->buffsize, 0);
115			overwrite (ctx);
116			}
117			} /* overwrite_random */
118
119
120			static void
121			overwrite_byte (int byte, wipe_context_s * ctx)
122			{
123			memset (ctx->buffer, byte, ctx->buffsize);
124			overwrite (ctx);
125			} /* overwrite_byte */
126
127
128			static void
129			overwrite_bytes (int byte1, int byte2, int byte3, wipe_context_s * ctx)
130			{
131			DWORD i;
132
133			memset (ctx->buffer, byte1, ctx->buffsize);
134			for (i = 1; i < ctx->buffsize; i += 3) {
135			ctx->buffer[i] = byte2;
136			ctx->buffer[i+1] = byte3;
137			}
138			overwrite (ctx);
139			} /* overwrite_bytes */
140
141
142			/**
143			* For the case the file is not a regular file (this is true for
144			* devices or directories) this function tries to rename the file
145			* to random pattern and then it will be delete (without random!).
146			**/
147			int
148			rename_unlink (const char * path)
149			{
150			struct stat statbuf;
151			char * new_name = NULL, * p = NULL, c;
152			int i = 0, rc = 0;
153			int is_dir = 0;
154
155			if (GetFileAttributes (path) & FILE_ATTRIBUTE_DIRECTORY)
156			is_dir = 1;
157
158			new_name = new char[strlen (path)+15];
159			if (!new_name)
160			BUG (0);
161
162			strcpy (new_name, path);
163			p = strrchr (new_name, '\\');
164			if (p != NULL) {
165			p++;
166			*p = '\0';
167			}
168			else
169			p = new_name;
170			do {
171			while (i < 14) {
172			c = gpg_random_char (1);
173			*p = c;
174			p++;
175			i++;
176			}
177			*p = '\0';
178			} while (stat (new_name, &statbuf) == 0);
179
180			if (rename (path, new_name) == -1) {
181			rc = WPTERR_FILE_READ;
182			goto leave;
183			}
184			if (is_dir && RemoveDirectory (new_name) == FALSE)
185			rc = WPTERR_FILE_REMOVE;
186			else if (!DeleteFile (new_name))
187			rc = WPTERR_FILE_REMOVE;
188
189			leave:
190			free_if_alloc (new_name);
191			return rc;
192			} /* rename_unlink */
193
194
195			static __int64
196			GetFileSize64 (const char * path)
197			{
198			FILE *fp = fopen (path, "r");
199			if (fp) {
200			struct _stati64 statbuf;
201			_fstati64 (fileno (fp), &statbuf);
202			fclose (fp);
203			return statbuf.st_size;
204			}
205			return -1;
206			} /* GetFileSize64 */
207
208
209			static int
210			_secure_unlink (const char * path, int mode, HANDLE *r_fd)
211			{
212			wipe_context_s ctx;
213			LONG size_high = 0;
214
215			if (GetFileAttributes (path) & FILE_ATTRIBUTE_DIRECTORY)
216			return rename_unlink (path);
217
218			memset (&ctx, 0, sizeof (ctx));
219			ctx.name = path;
220			ctx.buffsize = 16384;
221			ctx.buffer = new byte[ctx.buffsize];
222			if (!ctx.buffer)
223			BUG (0);
224
225			ctx.filesize = GetFileSize64 (path);
226			if (!ctx.filesize) {
227			free_if_alloc (ctx.buffer);
228			return WPTERR_FILE_ZERO;
229			}
230
231			ctx.fd = CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL,
232			OPEN_ALWAYS, 0, NULL);
233			if (ctx.fd == INVALID_HANDLE_VALUE) {
234			free_if_alloc (ctx.buffer);
235			return WPTERR_FILE_OPEN;
236			}
237			else if (r_fd)
238			*r_fd = ctx.fd;
239
240			gpg_quick_random_gen (1);
241			if (unlink_cb)
242			unlink_cb (unlink_cb_value, ctx.name, 0, 0, 0);
243
244			switch (mode) {
245			case WIPE_MODE_FAST:
246			ctx.n_passes = 1;
247			overwrite_random (1, &ctx);
248			break;
249
250			case WIPE_MODE_SIMPLE:
251			ctx.n_passes = 2;
252			overwrite_random (2, &ctx);
253			break;
254
255			case WIPE_MODE_DOD:
256			ctx.n_passes = 5;
257			overwrite_random (1, &ctx);
258			overwrite_byte ((~1) & 0xFF, &ctx);
259			overwrite_random (1, &ctx);
260			overwrite_byte ((~4) & 0xFF, &ctx);
261			overwrite_random (1, &ctx);
262			break;
263
264			case WIPE_MODE_GUTMANN:
265			ctx.n_passes = 39;
266			overwrite_random (4, &ctx);
267			overwrite_byte( 0x55, &ctx );
268			overwrite_byte ( 0xAA, &ctx );
269			overwrite_bytes( 0x92, 0x49, 0x24, &ctx );
270			overwrite_bytes( 0x49, 0x24, 0x92, &ctx );
271			overwrite_bytes( 0x24, 0x92, 0x49, &ctx );
272			overwrite_byte( 0x00, &ctx );
273			overwrite_byte( 0x11, &ctx );
274			overwrite_byte( 0x22, &ctx );
275			overwrite_byte( 0x33, &ctx );
276			overwrite_byte( 0x44, &ctx );
277			overwrite_byte( 0x55, &ctx );
278			overwrite_byte( 0x66, &ctx );
279			overwrite_byte( 0x77, &ctx );
280			overwrite_byte( 0x88, &ctx );
281			overwrite_byte( 0x99, &ctx );
282			overwrite_byte( 0xAA, &ctx );
283			overwrite_byte( 0xBB, &ctx );
284			overwrite_byte( 0xCC, &ctx );
285			overwrite_byte( 0xDD, &ctx );
286			overwrite_byte( 0xEE, &ctx );
287			overwrite_byte( 0xFF, &ctx );
288			overwrite_bytes( 0x92, 0x49, 0x24, &ctx );
289			overwrite_bytes( 0x49, 0x24, 0x92, &ctx );
290			overwrite_bytes( 0x24, 0x92, 0x49, &ctx );
291			overwrite_bytes( 0x6D, 0xB6, 0xDB, &ctx );
292			overwrite_bytes( 0xB6, 0xDB, 0x6D, &ctx );
293			overwrite_bytes( 0xDB, 0x6D, 0xB6, &ctx );
294			overwrite_random( 4, &ctx );
295			break;
296			}
297
298			/* Set file length to zero so allocated clusters cannot be trailed */
299			SetFilePointer (ctx.fd, 0, &size_high, FILE_BEGIN);
300			SetEndOfFile (ctx.fd);
301			CloseHandle (ctx.fd);
302
303			memset (ctx.buffer, 0, ctx.buffsize); /* burn the last evidence */
304			free_if_alloc (ctx.buffer);
305
306			return rename_unlink (path);
307			}
308
309			int
310			secure_unlink (const char *path, int mode)
311			{
312			return _secure_unlink (path, mode, NULL);
313			} /* secure_unlink */
314
315
316
317			void
318			secure_unlink_set_cb (void (cb)(void , const char *, int, unsigned, unsigned),
319			void *cb_value)
320			{
321			unlink_cb = cb;
322			unlink_cb_value = cb_value;
323			} /* secure_unlink_set_cb */
324
325
326			/* Windows 98 - Q188074 */
327			#define REGISTRY_FILESYSTEM "System\\CurrentControlSet\\Control\\FileSystem"
328			#define REGISTRY_LOWDISKSPACE "DisableLowDiskSpaceBroadcast"
329
330
331			/* disables the annoying warning Windows 98 displays when disk space is low */
332			static void
333			handle_lowdiskspace_notify( const char * drive, int disable )
334			{
335			OSVERSIONINFO ov;
336			HKEY key;
337			DWORD n;
338
339			memset( &ov, 0, sizeof ov );
340			ov.dwOSVersionInfoSize = sizeof ov;
341			GetVersionEx( &ov );
342			if( ov.dwPlatformId == VER_PLATFORM_WIN32_NT )
343			return;
344
345			if( disable ) {
346			unsigned newi = (1 << (toupper((unsigned)drive) - (unsigned)'A'));
347			if( RegOpenKey( HKEY_LOCAL_MACHINE, REGISTRY_FILESYSTEM, &key ) ) {
348			n = sizeof newi;
349			RegSetValue( key, REGISTRY_LOWDISKSPACE, REG_DWORD, (LPCTSTR)newi, n );
350			RegCloseKey( key );
351			}
352			}
353			else {
354			if( RegOpenKey( HKEY_LOCAL_MACHINE, REGISTRY_FILESYSTEM, &key ) ) {
355			RegDeleteKey( key, REGISTRY_LOWDISKSPACE );
356			RegCloseKey( key );
357			}
358			}
359			} /* handle_lowdiskspace_notify */
360
361
362			int
363			wipe_freespace (const char * drive, HANDLE *r_fd,
364			void (cb)(void , DDWORD, DDWORD), void * cb_value)
365			{
366			ULARGE_INTEGER caller, total, frees;
367			LONG hpart=0;
368			HANDLE fd;
369			int disktyp = GetDriveType (drive);
370			int rc;
371			char * file;
372
373			if (disktyp != DRIVE_FIXED && disktyp != DRIVE_REMOVABLE)
374			return -1;
375			if (!GetDiskFreeSpaceEx (drive, &caller, &total, &frees))
376			return -1;
377			handle_lowdiskspace_notify (drive, 1);
378
379			if (!frees.LowPart)
380			return WPTERR_FILE_ZERO;
381			file = new char[strlen (drive)+8];
382			if (!file)
383			BUG (0);
384			sprintf (file, "%stemp_winpt.tmp", drive);
385			fd = CreateFile (file,
386			GENERIC_READ\|GENERIC_WRITE,
387			FILE_SHARE_READ\|FILE_SHARE_WRITE,
388			NULL, CREATE_ALWAYS, 0, NULL);
389			if (fd == INVALID_HANDLE_VALUE) {
390			free_if_alloc (file);
391			return WPTERR_FILE_OPEN;
392			}
393			hpart = frees.HighPart;
394			SetFilePointer (fd, frees.LowPart, &hpart, FILE_BEGIN);
395			SetEndOfFile (fd);
396			CloseHandle (fd);
397
398			if (cb && cb_value) {
399			progress_cb = cb;
400			progress_cb_value = cb_value;
401			}
402			rc = _secure_unlink (file, WIPE_MODE_FAST, r_fd);
403
404			handle_lowdiskspace_notify (drive, 0);
405			free_if_alloc (file);
406			return rc;
407			} /* wipe_freespace */