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- Committer: Teddy Hogeborn
- Date: 2008-08-10 00:12:22 UTC
- mfrom: (24.1.34 mandos)
- Revision ID: teddy@fukt.bsnet.se-20080810001222-2apzjania6io2619
Merge.
- files added:
- network-protocol.txt
- files removed:
- .bzr-builddeb
- debian
- debian/po
- files renamed:
- plugin-runner.c => mandos-client.c
- plugin-runner.xml => mandos-client.xml
- plugins.d/mandos-client.c => plugins.d/password-request.c
- plugins.d/mandos-client.xml => plugins.d/password-request.xml
- files modified:
- Makefile
added
removed
plugins.d/splashy.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Splashy - Read a password from splashy and output it
4
*
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* Copyright © 2008,2009 Teddy Hogeborn
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* Copyright © 2008,2009 Björn Påhlsson
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*
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* This program is free software: you can redistribute it and/or
9
* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, either version 3 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see
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* <http://www.gnu.org/licenses/>.
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*
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* Contact the authors at <mandos@fukt.bsnet.se>.
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*/
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25
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
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#include <signal.h> /* sig_atomic_t, struct sigaction,
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sigemptyset(), sigaddset(), SIGINT,
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SIGHUP, SIGTERM, sigaction,
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SIG_IGN, kill(), SIGKILL */
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#include <stddef.h> /* NULL */
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#include <stdlib.h> /* getenv() */
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#include <stdio.h> /* asprintf(), perror() */
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#include <stdlib.h> /* EXIT_FAILURE, free(),
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EXIT_SUCCESS */
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#include <sys/types.h> /* pid_t, DIR, struct dirent,
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ssize_t */
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#include <dirent.h> /* opendir(), readdir(), closedir() */
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#include <inttypes.h> /* intmax_t, strtoimax() */
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#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
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#include <iso646.h> /* not, or, and */
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#include <unistd.h> /* readlink(), fork(), execl(),
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sleep(), dup2() STDERR_FILENO,
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STDOUT_FILENO, _exit(),
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pause() */
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#include <string.h> /* memcmp() */
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#include <errno.h> /* errno */
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#include <sys/wait.h> /* waitpid(), WIFEXITED(),
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WEXITSTATUS() */
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sig_atomic_t interrupted_by_signal = 0;
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int signal_received;
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static void termination_handler(int signum){
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if(interrupted_by_signal){
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return;
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}
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interrupted_by_signal = 1;
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signal_received = signum;
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}
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int main(__attribute__((unused))int argc,
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__attribute__((unused))char **argv){
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int ret = 0;
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char *prompt = NULL;
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DIR *proc_dir = NULL;
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pid_t splashy_pid = 0;
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pid_t splashy_command_pid = 0;
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/* Create prompt string */
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{
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const char *const cryptsource = getenv("cryptsource");
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const char *const crypttarget = getenv("crypttarget");
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const char *const prompt_start = "getpass "
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"Enter passphrase to unlock the disk";
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if(cryptsource == NULL){
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if(crypttarget == NULL){
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ret = asprintf(&prompt, "%s: ", prompt_start);
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} else {
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ret = asprintf(&prompt, "%s (%s): ", prompt_start,
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crypttarget);
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}
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} else {
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if(crypttarget == NULL){
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ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
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} else {
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ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
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cryptsource, crypttarget);
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}
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}
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if(ret == -1){
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prompt = NULL;
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goto failure;
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}
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}
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/* Find splashy process */
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{
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const char splashy_name[] = "/sbin/splashy";
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proc_dir = opendir("/proc");
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if(proc_dir == NULL){
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perror("opendir");
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goto failure;
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}
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for(struct dirent *proc_ent = readdir(proc_dir);
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proc_ent != NULL;
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proc_ent = readdir(proc_dir)){
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pid_t pid;
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{
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intmax_t tmpmax;
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char *tmp;
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errno = 0;
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tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
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if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
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or tmpmax != (pid_t)tmpmax){
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/* Not a process */
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continue;
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}
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pid = (pid_t)tmpmax;
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}
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/* Find the executable name by doing readlink() on the
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/proc/<pid>/exe link */
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char exe_target[sizeof(splashy_name)];
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ssize_t sret;
125
{
126
char *exe_link;
127
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
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if(ret == -1){
129
perror("asprintf");
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goto failure;
131
}
132
133
/* Check that it refers to a symlink owned by root:root */
134
struct stat exe_stat;
135
ret = lstat(exe_link, &exe_stat);
136
if(ret == -1){
137
if(errno == ENOENT){
138
free(exe_link);
139
continue;
140
}
141
perror("lstat");
142
free(exe_link);
143
goto failure;
144
}
145
if(not S_ISLNK(exe_stat.st_mode)
146
or exe_stat.st_uid != 0
147
or exe_stat.st_gid != 0){
148
free(exe_link);
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continue;
150
}
151
152
sret = readlink(exe_link, exe_target, sizeof(exe_target));
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free(exe_link);
154
}
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if((sret == ((ssize_t)sizeof(exe_target)-1))
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and (memcmp(splashy_name, exe_target,
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sizeof(exe_target)-1) == 0)){
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splashy_pid = pid;
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break;
160
}
161
}
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closedir(proc_dir);
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proc_dir = NULL;
164
}
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if(splashy_pid == 0){
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goto failure;
167
}
168
169
/* Set up the signal handler */
170
{
171
struct sigaction old_action,
172
new_action = { .sa_handler = termination_handler,
173
.sa_flags = 0 };
174
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
}
190
ret = sigaction(SIGINT, NULL, &old_action);
191
if(ret == -1){
192
perror("sigaction");
193
goto failure;
194
}
195
if(old_action.sa_handler != SIG_IGN){
196
ret = sigaction(SIGINT, &new_action, NULL);
197
if(ret == -1){
198
perror("sigaction");
199
goto failure;
200
}
201
}
202
ret = sigaction(SIGHUP, NULL, &old_action);
203
if(ret == -1){
204
perror("sigaction");
205
goto failure;
206
}
207
if(old_action.sa_handler != SIG_IGN){
208
ret = sigaction(SIGHUP, &new_action, NULL);
209
if(ret == -1){
210
perror("sigaction");
211
goto failure;
212
}
213
}
214
ret = sigaction(SIGTERM, NULL, &old_action);
215
if(ret == -1){
216
perror("sigaction");
217
goto failure;
218
}
219
if(old_action.sa_handler != SIG_IGN){
220
ret = sigaction(SIGTERM, &new_action, NULL);
221
if(ret == -1){
222
perror("sigaction");
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goto failure;
224
}
225
}
226
}
227
228
if(interrupted_by_signal){
229
goto failure;
230
}
231
232
/* 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){
244
const char splashy_command[] = "/sbin/splashy_update";
245
execl(splashy_command, splashy_command, prompt, (char *)NULL);
246
perror("execl");
247
}
248
free(prompt);
249
_exit(EXIT_FAILURE);
250
}
251
252
/* Parent */
253
free(prompt);
254
prompt = NULL;
255
256
if(interrupted_by_signal){
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goto failure;
258
}
259
260
/* Wait for command to complete */
261
{
262
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
}
270
if(ret == -1){
271
perror("waitpid");
272
if(errno == ECHILD){
273
splashy_command_pid = 0;
274
}
275
} else {
276
/* The child process has exited */
277
splashy_command_pid = 0;
278
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
279
return EXIT_SUCCESS;
280
}
281
}
282
}
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);
327
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());
349
}
350
351
return EXIT_FAILURE;
352
}
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