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- Committer: Teddy Hogeborn
- Date: 2008-10-04 20:19:58 UTC
- Revision ID: teddy@fukt.bsnet.se-20081004201958-a7iql0rss7yf6leu
* Makefile (FORTIFY): Added "-fPIE -pie".
(LINK_FORTIFY): New; set to "-z relro -pie".
(LDFLAGS): Use $(LINK_FORTIFY).
(LINK_FORTIFY): New; set to "-z relro -pie".
(LDFLAGS): Use $(LINK_FORTIFY).
- files added:
- debian/mandos-client.config
- files removed:
- NEWS
- files modified:
- INSTALL
added
removed
plugins.d/splashy.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Splashy - Read a password from splashy and output it
4
*
5
* Copyright © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
7
*
8
* This program is free software: you can redistribute it and/or
9
* modify it under the terms of the GNU General Public License as
10
* published by the Free Software Foundation, either version 3 of the
11
* License, or (at your option) any later version.
12
*
13
* This program is distributed in the hope that it will be useful, but
14
* WITHOUT ANY WARRANTY; without even the implied warranty of
15
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16
* General Public License for more details.
17
*
18
* You should have received a copy of the GNU General Public License
19
* along with this program. If not, see
20
* <http://www.gnu.org/licenses/>.
21
*
22
* Contact the authors at <mandos@fukt.bsnet.se>.
23
*/
24
25
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
1
#define _GNU_SOURCE /* asprintf() */
26
2
#include <signal.h> /* sig_atomic_t, struct sigaction,
27
3
sigemptyset(), sigaddset(), SIGINT,
28
4
SIGHUP, SIGTERM, sigaction,
30
6
#include <stddef.h> /* NULL */
31
7
#include <stdlib.h> /* getenv() */
32
8
#include <stdio.h> /* asprintf(), perror() */
33
#include <stdlib.h> /* EXIT_FAILURE, free(),
9
#include <stdlib.h> /* EXIT_FAILURE, free(), strtoul(),
34
10
EXIT_SUCCESS */
35
11
#include <sys/types.h> /* pid_t, DIR, struct dirent,
36
12
ssize_t */
37
13
#include <dirent.h> /* opendir(), readdir(), closedir() */
38
#include <inttypes.h> /* intmax_t, strtoimax() */
39
14
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
40
15
#include <iso646.h> /* not, or, and */
41
16
#include <unistd.h> /* readlink(), fork(), execl(),
42
17
sleep(), dup2() STDERR_FILENO,
43
STDOUT_FILENO, _exit(),
44
pause() */
18
STDOUT_FILENO, _exit() */
45
19
#include <string.h> /* memcmp() */
46
20
#include <errno.h> /* errno */
47
21
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
48
22
WEXITSTATUS() */
49
23
50
24
sig_atomic_t interrupted_by_signal = 0;
51
int signal_received;
52
25
53
static void termination_handler(int signum){
54
if(interrupted_by_signal){
55
return;
56
}
26
static void termination_handler(__attribute__((unused))int signum){
57
27
interrupted_by_signal = 1;
58
signal_received = signum;
59
28
}
60
29
61
30
int main(__attribute__((unused))int argc,
62
31
__attribute__((unused))char **argv){
63
32
int ret = 0;
33
34
/* Create prompt string */
64
35
char *prompt = NULL;
65
DIR *proc_dir = NULL;
66
pid_t splashy_pid = 0;
67
pid_t splashy_command_pid = 0;
68
69
/* Create prompt string */
70
36
{
71
37
const char *const cryptsource = getenv("cryptsource");
72
38
const char *const crypttarget = getenv("crypttarget");
89
55
}
90
56
}
91
57
if(ret == -1){
92
prompt = NULL;
93
goto failure;
58
return EXIT_FAILURE;
94
59
}
95
60
}
96
61
97
62
/* Find splashy process */
63
pid_t splashy_pid = 0;
98
64
{
99
65
const char splashy_name[] = "/sbin/splashy";
100
proc_dir = opendir("/proc");
66
DIR *proc_dir = opendir("/proc");
101
67
if(proc_dir == NULL){
68
free(prompt);
102
69
perror("opendir");
103
goto failure;
70
return EXIT_FAILURE;
104
71
}
105
72
for(struct dirent *proc_ent = readdir(proc_dir);
106
73
proc_ent != NULL;
107
74
proc_ent = readdir(proc_dir)){
108
pid_t pid;
109
{
110
intmax_t tmpmax;
111
char *tmp;
112
errno = 0;
113
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
114
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
115
or tmpmax != (pid_t)tmpmax){
116
/* Not a process */
117
continue;
118
}
119
pid = (pid_t)tmpmax;
75
pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
76
if(pid == 0){
77
/* Not a process */
78
continue;
120
79
}
121
80
/* Find the executable name by doing readlink() on the
122
81
/proc/<pid>/exe link */
127
86
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
128
87
if(ret == -1){
129
88
perror("asprintf");
130
goto failure;
89
free(prompt);
90
closedir(proc_dir);
91
return EXIT_FAILURE;
131
92
}
132
93
133
94
/* Check that it refers to a symlink owned by root:root */
134
95
struct stat exe_stat;
135
96
ret = lstat(exe_link, &exe_stat);
136
97
if(ret == -1){
137
if(errno == ENOENT){
138
free(exe_link);
139
continue;
140
}
141
98
perror("lstat");
142
99
free(exe_link);
143
goto failure;
100
free(prompt);
101
closedir(proc_dir);
102
return EXIT_FAILURE;
144
103
}
145
104
if(not S_ISLNK(exe_stat.st_mode)
146
105
or exe_stat.st_uid != 0
160
119
}
161
120
}
162
121
closedir(proc_dir);
163
proc_dir = NULL;
164
122
}
165
123
if(splashy_pid == 0){
166
goto failure;
124
free(prompt);
125
return EXIT_FAILURE;
167
126
}
168
127
169
128
/* Set up the signal handler */
172
131
new_action = { .sa_handler = termination_handler,
173
132
.sa_flags = 0 };
174
133
sigemptyset(&new_action.sa_mask);
175
ret = sigaddset(&new_action.sa_mask, SIGINT);
176
if(ret == -1){
177
perror("sigaddset");
178
goto failure;
179
}
180
ret = sigaddset(&new_action.sa_mask, SIGHUP);
181
if(ret == -1){
182
perror("sigaddset");
183
goto failure;
184
}
185
ret = sigaddset(&new_action.sa_mask, SIGTERM);
186
if(ret == -1){
187
perror("sigaddset");
188
goto failure;
189
}
134
sigaddset(&new_action.sa_mask, SIGINT);
135
sigaddset(&new_action.sa_mask, SIGHUP);
136
sigaddset(&new_action.sa_mask, SIGTERM);
190
137
ret = sigaction(SIGINT, NULL, &old_action);
191
138
if(ret == -1){
192
139
perror("sigaction");
193
goto failure;
140
free(prompt);
141
return EXIT_FAILURE;
194
142
}
195
143
if(old_action.sa_handler != SIG_IGN){
196
144
ret = sigaction(SIGINT, &new_action, NULL);
197
145
if(ret == -1){
198
146
perror("sigaction");
199
goto failure;
147
free(prompt);
148
return EXIT_FAILURE;
200
149
}
201
150
}
202
151
ret = sigaction(SIGHUP, NULL, &old_action);
203
152
if(ret == -1){
204
153
perror("sigaction");
205
goto failure;
154
free(prompt);
155
return EXIT_FAILURE;
206
156
}
207
157
if(old_action.sa_handler != SIG_IGN){
208
158
ret = sigaction(SIGHUP, &new_action, NULL);
209
159
if(ret == -1){
210
160
perror("sigaction");
211
goto failure;
161
free(prompt);
162
return EXIT_FAILURE;
212
163
}
213
164
}
214
165
ret = sigaction(SIGTERM, NULL, &old_action);
215
166
if(ret == -1){
216
167
perror("sigaction");
217
goto failure;
168
free(prompt);
169
return EXIT_FAILURE;
218
170
}
219
171
if(old_action.sa_handler != SIG_IGN){
220
172
ret = sigaction(SIGTERM, &new_action, NULL);
221
173
if(ret == -1){
222
174
perror("sigaction");
223
goto failure;
175
free(prompt);
176
return EXIT_FAILURE;
224
177
}
225
178
}
226
179
}
227
180
228
if(interrupted_by_signal){
229
goto failure;
230
}
231
232
181
/* Fork off the splashy command to prompt for password */
233
splashy_command_pid = fork();
234
if(splashy_command_pid != 0 and interrupted_by_signal){
235
goto failure;
236
}
237
if(splashy_command_pid == -1){
238
perror("fork");
239
goto failure;
240
}
241
/* Child */
242
if(splashy_command_pid == 0){
243
if(not interrupted_by_signal){
182
pid_t splashy_command_pid = 0;
183
if(not interrupted_by_signal){
184
splashy_command_pid = fork();
185
if(splashy_command_pid == -1){
186
if(not interrupted_by_signal){
187
perror("fork");
188
}
189
return EXIT_FAILURE;
190
}
191
/* Child */
192
if(splashy_command_pid == 0){
244
193
const char splashy_command[] = "/sbin/splashy_update";
245
execl(splashy_command, splashy_command, prompt, (char *)NULL);
246
perror("execl");
194
ret = execl(splashy_command, splashy_command, prompt,
195
(char *)NULL);
196
if(not interrupted_by_signal){
197
perror("execl");
198
}
199
free(prompt);
200
_exit(EXIT_FAILURE);
247
201
}
248
free(prompt);
249
_exit(EXIT_FAILURE);
250
202
}
251
203
252
204
/* Parent */
253
205
free(prompt);
254
prompt = NULL;
255
256
if(interrupted_by_signal){
257
goto failure;
258
}
259
206
260
207
/* Wait for command to complete */
261
{
208
if(not interrupted_by_signal and splashy_command_pid != 0){
262
209
int status;
263
do {
264
ret = waitpid(splashy_command_pid, &status, 0);
265
} while(ret == -1 and errno == EINTR
266
and not interrupted_by_signal);
267
if(interrupted_by_signal){
268
goto failure;
269
}
210
ret = waitpid(splashy_command_pid, &status, 0);
270
211
if(ret == -1){
271
perror("waitpid");
212
if(errno != EINTR){
213
perror("waitpid");
214
}
272
215
if(errno == ECHILD){
273
216
splashy_command_pid = 0;
274
217
}
275
218
} else {
276
219
/* The child process has exited */
277
220
splashy_command_pid = 0;
278
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
221
if(not interrupted_by_signal and WIFEXITED(status)
222
and WEXITSTATUS(status)==0){
279
223
return EXIT_SUCCESS;
280
224
}
281
225
}
282
226
}
283
284
failure:
285
286
free(prompt);
287
288
if(proc_dir != NULL){
289
TEMP_FAILURE_RETRY(closedir(proc_dir));
290
}
291
292
if(splashy_command_pid != 0){
293
TEMP_FAILURE_RETRY(kill(splashy_command_pid, SIGTERM));
294
295
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGTERM));
296
sleep(2);
297
while(TEMP_FAILURE_RETRY(kill(splashy_pid, 0)) == 0){
298
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGKILL));
299
sleep(1);
300
}
301
pid_t new_splashy_pid = (pid_t)TEMP_FAILURE_RETRY(fork());
302
if(new_splashy_pid == 0){
303
/* Child; will become new splashy process */
304
305
/* Make the effective user ID (root) the only user ID instead of
306
the real user ID (_mandos) */
307
ret = setuid(geteuid());
308
if(ret == -1){
309
perror("setuid");
310
}
311
312
setsid();
313
ret = chdir("/");
314
if(ret == -1){
315
perror("chdir");
316
}
317
/* if(fork() != 0){ */
318
/* _exit(EXIT_SUCCESS); */
319
/* } */
320
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace stdout */
321
if(ret == -1){
322
perror("dup2");
323
_exit(EXIT_FAILURE);
324
}
325
326
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
227
kill(splashy_pid, SIGTERM);
228
if(interrupted_by_signal and splashy_command_pid != 0){
229
kill(splashy_command_pid, SIGTERM);
230
}
231
sleep(2);
232
while(kill(splashy_pid, 0) == 0){
233
kill(splashy_pid, SIGKILL);
234
sleep(1);
235
}
236
pid_t new_splashy_pid = fork();
237
if(new_splashy_pid == 0){
238
/* Child; will become new splashy process */
239
240
/* Make the effective user ID (root) the only user ID instead of
241
the real user ID (mandos) */
242
ret = setuid(geteuid());
243
if(ret == -1){
244
perror("setuid");
245
}
246
247
setsid();
248
ret = chdir("/");
249
/* if(fork() != 0){ */
250
/* _exit(EXIT_SUCCESS); */
251
/* } */
252
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
253
if(ret == -1){
254
perror("dup2");
255
_exit(EXIT_FAILURE);
256
}
257
258
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
259
if(not interrupted_by_signal){
327
260
perror("execl");
328
_exit(EXIT_FAILURE);
329
}
330
}
331
332
if(interrupted_by_signal){
333
struct sigaction signal_action;
334
sigemptyset(&signal_action.sa_mask);
335
signal_action.sa_handler = SIG_DFL;
336
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
337
&signal_action, NULL));
338
if(ret == -1){
339
perror("sigaction");
340
}
341
do {
342
ret = raise(signal_received);
343
} while(ret != 0 and errno == EINTR);
344
if(ret != 0){
345
perror("raise");
346
abort();
347
}
348
TEMP_FAILURE_RETRY(pause());
261
}
262
_exit(EXIT_FAILURE);
349
263
}
350
264
351
265
return EXIT_FAILURE;
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