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);
        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);
}

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);

    /* 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);

    handle_lowdiskspace_notify (drive, 0);
    free_if_alloc (file);
    return rc;
} /* wipe_freespace */
1	/* 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	unlink (path);
229	return 0;
230	}
231
232	ctx.fd = CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL,
233	OPEN_ALWAYS, 0, NULL);
234	if (ctx.fd == INVALID_HANDLE_VALUE) {
235	free_if_alloc (ctx.buffer);
236	return WPTERR_FILE_OPEN;
237	}
238	else if (r_fd)
239	*r_fd = ctx.fd;
240
241	gpg_quick_random_gen (1);
242	if (unlink_cb)
243	unlink_cb (unlink_cb_value, ctx.name, 0, 0, 0);
244
245	switch (mode) {
246	case WIPE_MODE_FAST:
247	ctx.n_passes = 1;
248	overwrite_random (1, &ctx);
249	break;
250
251	case WIPE_MODE_SIMPLE:
252	ctx.n_passes = 2;
253	overwrite_random (2, &ctx);
254	break;
255
256	case WIPE_MODE_DOD:
257	ctx.n_passes = 5;
258	overwrite_random (1, &ctx);
259	overwrite_byte ((~1) & 0xFF, &ctx);
260	overwrite_random (1, &ctx);
261	overwrite_byte ((~4) & 0xFF, &ctx);
262	overwrite_random (1, &ctx);
263	break;
264
265	case WIPE_MODE_GUTMANN:
266	ctx.n_passes = 39;
267	overwrite_random (4, &ctx);
268	overwrite_byte( 0x55, &ctx );
269	overwrite_byte ( 0xAA, &ctx );
270	overwrite_bytes( 0x92, 0x49, 0x24, &ctx );
271	overwrite_bytes( 0x49, 0x24, 0x92, &ctx );
272	overwrite_bytes( 0x24, 0x92, 0x49, &ctx );
273	overwrite_byte( 0x00, &ctx );
274	overwrite_byte( 0x11, &ctx );
275	overwrite_byte( 0x22, &ctx );
276	overwrite_byte( 0x33, &ctx );
277	overwrite_byte( 0x44, &ctx );
278	overwrite_byte( 0x55, &ctx );
279	overwrite_byte( 0x66, &ctx );
280	overwrite_byte( 0x77, &ctx );
281	overwrite_byte( 0x88, &ctx );
282	overwrite_byte( 0x99, &ctx );
283	overwrite_byte( 0xAA, &ctx );
284	overwrite_byte( 0xBB, &ctx );
285	overwrite_byte( 0xCC, &ctx );
286	overwrite_byte( 0xDD, &ctx );
287	overwrite_byte( 0xEE, &ctx );
288	overwrite_byte( 0xFF, &ctx );
289	overwrite_bytes( 0x92, 0x49, 0x24, &ctx );
290	overwrite_bytes( 0x49, 0x24, 0x92, &ctx );
291	overwrite_bytes( 0x24, 0x92, 0x49, &ctx );
292	overwrite_bytes( 0x6D, 0xB6, 0xDB, &ctx );
293	overwrite_bytes( 0xB6, 0xDB, 0x6D, &ctx );
294	overwrite_bytes( 0xDB, 0x6D, 0xB6, &ctx );
295	overwrite_random( 4, &ctx );
296	break;
297	}
298
299	/* Set file length to zero so allocated clusters cannot be trailed */
300	SetFilePointer (ctx.fd, 0, &size_high, FILE_BEGIN);
301	SetEndOfFile (ctx.fd);
302	CloseHandle (ctx.fd);
303
304	memset (ctx.buffer, 0, ctx.buffsize); /* burn the last evidence */
305	free_if_alloc (ctx.buffer);
306
307	return rename_unlink (path);
308	}
309
310	int
311	secure_unlink (const char *path, int mode)
312	{
313	return _secure_unlink (path, mode, NULL);
314	} /* secure_unlink */
315
316
317
318	void
319	secure_unlink_set_cb (void (cb)(void , const char *, int, unsigned, unsigned),
320	void *cb_value)
321	{
322	unlink_cb = cb;
323	unlink_cb_value = cb_value;
324	} /* secure_unlink_set_cb */
325
326
327	/* Windows 98 - Q188074 */
328	#define REGISTRY_FILESYSTEM "System\\CurrentControlSet\\Control\\FileSystem"
329	#define REGISTRY_LOWDISKSPACE "DisableLowDiskSpaceBroadcast"
330
331
332	/* disables the annoying warning Windows 98 displays when disk space is low */
333	static void
334	handle_lowdiskspace_notify( const char * drive, int disable )
335	{
336	OSVERSIONINFO ov;
337	HKEY key;
338	DWORD n;
339
340	memset( &ov, 0, sizeof ov );
341	ov.dwOSVersionInfoSize = sizeof ov;
342	GetVersionEx( &ov );
343	if( ov.dwPlatformId == VER_PLATFORM_WIN32_NT )
344	return;
345
346	if( disable ) {
347	unsigned newi = (1 << (toupper((unsigned)drive) - (unsigned)'A'));
348	if( RegOpenKey( HKEY_LOCAL_MACHINE, REGISTRY_FILESYSTEM, &key ) ) {
349	n = sizeof newi;
350	RegSetValue( key, REGISTRY_LOWDISKSPACE, REG_DWORD, (LPCTSTR)newi, n );
351	RegCloseKey( key );
352	}
353	}
354	else {
355	if( RegOpenKey( HKEY_LOCAL_MACHINE, REGISTRY_FILESYSTEM, &key ) ) {
356	RegDeleteKey( key, REGISTRY_LOWDISKSPACE );
357	RegCloseKey( key );
358	}
359	}
360	} /* handle_lowdiskspace_notify */
361
362
363	int
364	wipe_freespace (const char * drive, HANDLE *r_fd,
365	void (cb)(void , DDWORD, DDWORD), void * cb_value)
366	{
367	ULARGE_INTEGER caller, total, frees;
368	LONG hpart=0;
369	HANDLE fd;
370	int disktyp = GetDriveType (drive);
371	int rc;
372	char * file;
373
374	if (disktyp != DRIVE_FIXED && disktyp != DRIVE_REMOVABLE)
375	return -1;
376	if (!GetDiskFreeSpaceEx (drive, &caller, &total, &frees))
377	return -1;
378	handle_lowdiskspace_notify (drive, 1);
379
380	/* disk is full */
381	if (!frees.LowPart)
382	return 0;
383	file = new char[strlen (drive)+8];
384	if (!file)
385	BUG (0);
386	sprintf (file, "%stemp_winpt.tmp", drive);
387	fd = CreateFile (file,
388	GENERIC_READ\|GENERIC_WRITE,
389	FILE_SHARE_READ\|FILE_SHARE_WRITE,
390	NULL, CREATE_ALWAYS, 0, NULL);
391	if (fd == INVALID_HANDLE_VALUE) {
392	free_if_alloc (file);
393	return WPTERR_FILE_OPEN;
394	}
395	hpart = frees.HighPart;
396	SetFilePointer (fd, frees.LowPart, &hpart, FILE_BEGIN);
397	SetEndOfFile (fd);
398	CloseHandle (fd);
399
400	if (cb && cb_value) {
401	progress_cb = cb;
402	progress_cb_value = cb_value;
403	}
404	rc = _secure_unlink (file, WIPE_MODE_FAST, r_fd);
405
406	handle_lowdiskspace_notify (drive, 0);
407	free_if_alloc (file);
408	return rc;
409	} /* wipe_freespace */