1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
|
--- remove.c.orig 2003-05-05 15:15:48.000000000 +0200
+++ remove.c 2003-05-05 15:26:08.000000000 +0200
@@ -26,6 +26,12 @@
#include <sys/types.h>
#include <assert.h>
+/* SRM BEGIN */
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdlib.h>
+/* SRM END */
+
#if HAVE_STDBOOL_H
# include <stdbool.h>
#else
@@ -81,6 +87,18 @@
int euidaccess ();
int yesno ();
+/* SRM BEGIN */
+#define BLOCKSIZE 32769
+#define DIR_SEPERATOR '/'
+#define FLUSH sync()
+#define RANDOM_DEVICE "/dev/urandom"
+static int secure = 0;
+static char fillbuf[BLOCKSIZE];
+static FILE *devrandom;
+/* Functions */
+static int secure_delete();
+/* SRM END */
+
extern char *program_name;
/* state initialized by remove_init, freed by remove_fini */
@@ -605,6 +623,103 @@
return status;
}
+/* SRM BEGIN */
+void fill_buf(char pattern[3]) {
+ int loop;
+ int where;
+ for (loop = 0; loop < (BLOCKSIZE / 3); loop++) {
+ where = loop * 3;
+ fillbuf[where] = pattern[0];
+ fillbuf[where+1] = pattern[1];
+ fillbuf[where+2] = pattern[2];
+ }
+}
+
+void random_buf() {
+ int loop;
+ if (devrandom != NULL)
+ for (loop = 0; loop < BLOCKSIZE; loop++)
+ fillbuf[loop] = (unsigned char) (256.0*rand()/(RAND_MAX+1.0));
+ else
+ fread(&fillbuf, BLOCKSIZE, 1, devrandom);
+}
+
+/* overwriting the file several times */
+ static int
+ secure_delete (delfile)
+ char *delfile;
+ {
+ unsigned char write_modes[27][3] = {
+ {"\x55\x55\x55"}, {"\xaa\xaa\xaa"}, {"\x92\x49\x24"}, {"\x49\x24\x92"},
+ {"\x24\x92\x49"}, {"\x00\x00\x00"}, {"\x11\x11\x11"}, {"\x22\x22\x22"},
+ {"\x33\x33\x33"}, {"\x44\x44\x44"}, {"\x55\x55\x55"}, {"\x66\x66\x66"},
+ {"\x77\x77\x77"}, {"\x88\x88\x88"}, {"\x99\x99\x99"}, {"\xaa\xaa\xaa"},
+ {"\xbb\xbb\xbb"}, {"\xcc\xcc\xcc"}, {"\xdd\xdd\xdd"}, {"\xee\xee\xee"},
+ {"\xff\xff\xff"}, {"\x92\x49\x24"}, {"\x49\x24\x92"}, {"\x24\x92\x49"},
+ {"\x6d\xb6\xdb"}, {"\xb6\xdb\x6d"}, {"\xdb\x6d\xb6"}
+ };
+ unsigned char std_array[3] = "\xff\xff\xff";
+ FILE *f;
+ int file;
+ unsigned long writes;
+ unsigned long counter;
+ unsigned long filesize;
+ struct stat filestat;
+ int turn;
+ int result;
+ unsigned char ch;
+ char newname[512];
+
+/* open the file, get the filesize, calculate the numbers of needed writings */
+ if (lstat(delfile, &filestat))
+ return 1;
+ if (! S_ISREG(filestat.st_mode))
+ return 1;
+ if ((f = fopen(delfile, "r+b")) == NULL)
+ return 1;
+ filesize = filestat.st_size;
+ writes = (1 + (filesize / BLOCKSIZE));
+ file=fileno(f);
+ (void) setvbuf(stdout, NULL, _IONBF, 0);
+ devrandom = fopen(RANDOM_DEVICE, "r");
+
+ if (secure > 1) {
+ fill_buf(std_array);
+ for (counter=1; counter<=writes; counter++)
+ fwrite(&fillbuf, 1, BLOCKSIZE, f);
+ fflush(f);
+ fsync(file);
+ }
+
+/* do the overwriting stuff */
+ for (turn=0; turn<=36; turn++) {
+ rewind(f);
+ if ((secure < 3) && (turn > 0)) break;
+ if ((turn>=5) && (turn<=31)) {
+ fill_buf(write_modes[turn-5]);
+ for (counter=1; counter<=writes; counter++)
+ fwrite(&fillbuf, 1, BLOCKSIZE, f);
+ } else {
+ for (counter=1; counter<=writes; counter++) {
+ random_buf();
+ fwrite(&fillbuf, 1, BLOCKSIZE, f);
+ }
+ }
+ fflush(f);
+ if (fsync(file) < 0)
+ FLUSH;
+ }
+ (void) fclose(f);
+ (void) fclose(devrandom);
+/* Hard Flush -> Force cached data to be written to disk */
+ FLUSH;
+/* open + truncating the file, so an attacker doesn't know the diskblocks */
+ if ((file = open(delfile, O_WRONLY | O_TRUNC)) >= 0)
+ close(file);
+ return 0;
+}
+/* SRM END */
+
/* Query the user if appropriate, and if ok try to remove the
file or directory specified by FS. Return RM_OK if it is removed,
and RM_ERROR or RM_USER_DECLINED if not. */
@@ -646,9 +761,16 @@
return RM_USER_DECLINED;
}
- if (x->verbose)
- printf (_("removing %s\n"), quote (full_filename (pathname)));
+ if (x->verbose) {
+ if (secure)
+ printf (_("wiping %s\n"), quote (full_filename (pathname)));
+ else
+ printf (_("removing %s\n"), quote (full_filename (pathname)));
+ }
+ if (secure)
+ secure_delete(pathname);
+
if (unlink (pathname) && (errno != ENOENT || !x->ignore_missing_files))
{
error (0, errno, _("cannot unlink %s"), quote (full_filename (pathname)));
@@ -821,6 +943,8 @@
{
mode_t filetype_mode;
+ secure = x->secure;
+
if (user_specified_name)
{
/* CAUTION: this use of base_name works only because any
--- rm.c.orig 2003-05-05 14:58:35.000000000 +0200
+++ rm.c 2003-05-05 15:16:31.000000000 +0200
@@ -58,7 +58,7 @@
#define PROGRAM_NAME "rm"
#define AUTHORS \
- "Paul Rubin, David MacKenzie, Richard Stallman, and Jim Meyering"
+ "Paul Rubin, David MacKenzie, Richard Stallman, Jim Meyering, and van Hauser"
void strip_trailing_slashes ();
@@ -71,6 +71,9 @@
{"force", no_argument, NULL, 'f'},
{"interactive", no_argument, NULL, 'i'},
{"recursive", no_argument, NULL, 'r'},
+/* SRM BEGIN */
+ {"secure", no_argument, NULL, 's'},
+/* SRM END */
{"verbose", no_argument, NULL, 'v'},
{GETOPT_HELP_OPTION_DECL},
{GETOPT_VERSION_OPTION_DECL},
@@ -93,6 +96,7 @@
-f, --force ignore nonexistent files, never prompt\n\
-i, --interactive prompt before any removal\n\
-r, -R, --recursive remove the contents of directories recursively\n\
+ -s, --secure secure overwrite (-sss for full security)\n\
-v, --verbose explain what is being done\n\
--help display this help and exit\n\
--version output version information and exit\n\
@@ -105,10 +109,11 @@
\n\
Note that if you use rm to remove a file, it is usually possible to recover\n\
the contents of that file. If you want more assurance that the contents are\n\
-truly unrecoverable, consider using shred.\n\
+truly unrecoverable, use the -s option.\n\
"),
program_name, program_name);
puts (_("\nReport bugs to <bug-fileutils@gnu.org>."));
+ puts (_("\nWith secure_delete patch by van Hauser <vh@thc.org>"));
}
exit (status);
}
@@ -122,6 +127,7 @@
x->recursive = 0;
x->stdin_tty = isatty (STDIN_FILENO);
x->verbose = 0;
+ x->secure = 0;
}
int
@@ -140,7 +146,7 @@
rm_option_init (&x);
- while ((c = getopt_long (argc, argv, "dfirvR", long_opts, NULL)) != -1)
+ while ((c = getopt_long (argc, argv, "dfirsvR", long_opts, NULL)) != -1)
{
switch (c)
{
@@ -161,6 +167,11 @@
case 'R':
x.recursive = 1;
break;
+/* SRM BEGIN */
+ case 's':
+ x.secure++;
+ break;
+/* SRM END */
case 'v':
x.verbose = 1;
break;
--- remove.h.orig 2003-05-05 15:13:47.000000000 +0200
+++ remove.h 2003-05-05 15:14:13.000000000 +0200
@@ -18,6 +18,9 @@
Only works for the super-user. */
int unlink_dirs;
+ /* If nonzero, secure overwrites file contents */
+ int secure;
+
/* If nonzero, display the name of each file removed. */
int verbose;
};
|
