To get this branch, use:
bzr branch
http://bzr.recompile.se/loggerhead/mandos/trunk
« back to all changes in this revision
Viewing changes to plugins.d/usplash.c
- browse files at revision 13
- compare with another revision
- download diff
- download tarball
- view history from revision 13
- Committer: Björn Påhlsson
- Date: 2008-07-20 02:52:20 UTC
- Revision ID: belorn@braxen-20080720025220-r5u0388uy9iu23h6
Added following support:
Pluginbased client handler
rewritten Mandos client
Avahi instead of udp server discovery
openpgp encrypted key support
Passprompt stand alone application for direct console input
Added logging for Mandos server
Pluginbased client handler
rewritten Mandos client
Avahi instead of udp server discovery
openpgp encrypted key support
Passprompt stand alone application for direct console input
Added logging for Mandos server
- files added:
- ca.pem
- files removed:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- files renamed:
- clients.conf => mandos-clients.conf
- plugin-runner.c => plugbasedclient.c
- plugins.d/mandos-client.c => plugins.d/mandosclient.c
- plugins.d/password-prompt.c => plugins.d/passprompt.c
- mandos => server.py
- files modified:
- Makefile
added
removed
plugins.d/usplash.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Usplash - Read a password from usplash and output it
4
*
5
* Copyright © 2008-2011 Teddy Hogeborn
6
* Copyright © 2008-2011 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@recompile.se>.
23
*/
24
25
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
26
#include <signal.h> /* sig_atomic_t, struct sigaction,
27
sigemptyset(), sigaddset(), SIGINT,
28
SIGHUP, SIGTERM, sigaction(),
29
SIG_IGN, kill(), SIGKILL */
30
#include <stdbool.h> /* bool, false, true */
31
#include <fcntl.h> /* open(), O_WRONLY, O_RDONLY */
32
#include <iso646.h> /* and, or, not*/
33
#include <errno.h> /* errno, EINTR */
34
#include <error.h>
35
#include <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
36
dirent */
37
#include <stddef.h> /* NULL */
38
#include <string.h> /* strlen(), memcmp(), strerror() */
39
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(),
40
fprintf() */
41
#include <unistd.h> /* close(), write(), readlink(),
42
read(), STDOUT_FILENO, sleep(),
43
fork(), setuid(), geteuid(),
44
setsid(), chdir(), dup2(),
45
STDERR_FILENO, execv() */
46
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
47
EXIT_SUCCESS, malloc(), _exit(),
48
getenv() */
49
#include <dirent.h> /* opendir(), readdir(), closedir() */
50
#include <inttypes.h> /* intmax_t, strtoimax() */
51
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
52
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
53
#include <argz.h> /* argz_count(), argz_extract() */
54
#include <stdarg.h> /* va_list, va_start(), ... */
55
56
sig_atomic_t interrupted_by_signal = 0;
57
int signal_received;
58
const char usplash_name[] = "/sbin/usplash";
59
60
/* Function to use when printing errors */
61
void error_plus(int status, int errnum, const char *formatstring,
62
...){
63
va_list ap;
64
char *text;
65
int ret;
66
67
va_start(ap, formatstring);
68
ret = vasprintf(&text, formatstring, ap);
69
if (ret == -1){
70
fprintf(stderr, "Mandos plugin %s: ",
71
program_invocation_short_name);
72
vfprintf(stderr, formatstring, ap);
73
fprintf(stderr, ": ");
74
fprintf(stderr, "%s\n", strerror(errnum));
75
error(status, errno, "vasprintf while printing error");
76
return;
77
}
78
fprintf(stderr, "Mandos plugin ");
79
error(status, errnum, "%s", text);
80
free(text);
81
}
82
83
static void termination_handler(int signum){
84
if(interrupted_by_signal){
85
return;
86
}
87
interrupted_by_signal = 1;
88
signal_received = signum;
89
}
90
91
static bool usplash_write(int *fifo_fd_r,
92
const char *cmd, const char *arg){
93
/*
94
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
95
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
96
* SEE ALSO
97
* usplash_write(8)
98
*/
99
int ret;
100
if(*fifo_fd_r == -1){
101
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
102
if(ret == -1){
103
return false;
104
}
105
*fifo_fd_r = ret;
106
}
107
108
const char *cmd_line;
109
size_t cmd_line_len;
110
char *cmd_line_alloc = NULL;
111
if(arg == NULL){
112
cmd_line = cmd;
113
cmd_line_len = strlen(cmd) + 1;
114
} else {
115
do {
116
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
117
if(ret == -1){
118
int e = errno;
119
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
120
errno = e;
121
return false;
122
}
123
} while(ret == -1);
124
cmd_line = cmd_line_alloc;
125
cmd_line_len = (size_t)ret + 1;
126
}
127
128
size_t written = 0;
129
ssize_t sret = 0;
130
while(written < cmd_line_len){
131
sret = write(*fifo_fd_r, cmd_line + written,
132
cmd_line_len - written);
133
if(sret == -1){
134
int e = errno;
135
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
136
free(cmd_line_alloc);
137
errno = e;
138
return false;
139
}
140
written += (size_t)sret;
141
}
142
free(cmd_line_alloc);
143
144
return true;
145
}
146
147
/* Create prompt string */
148
char *makeprompt(void){
149
int ret = 0;
150
char *prompt;
151
const char *const cryptsource = getenv("cryptsource");
152
const char *const crypttarget = getenv("crypttarget");
153
const char prompt_start[] = "Enter passphrase to unlock the disk";
154
155
if(cryptsource == NULL){
156
if(crypttarget == NULL){
157
ret = asprintf(&prompt, "%s: ", prompt_start);
158
} else {
159
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
160
crypttarget);
161
}
162
} else {
163
if(crypttarget == NULL){
164
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
165
} else {
166
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
167
cryptsource, crypttarget);
168
}
169
}
170
if(ret == -1){
171
return NULL;
172
}
173
return prompt;
174
}
175
176
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
177
int ret = 0;
178
ssize_t sret = 0;
179
char *cmdline = NULL;
180
size_t cmdline_len = 0;
181
DIR *proc_dir = opendir("/proc");
182
if(proc_dir == NULL){
183
error_plus(0, errno, "opendir");
184
return -1;
185
}
186
errno = 0;
187
for(struct dirent *proc_ent = readdir(proc_dir);
188
proc_ent != NULL;
189
proc_ent = readdir(proc_dir)){
190
pid_t pid;
191
{
192
intmax_t tmpmax;
193
char *tmp;
194
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
195
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
196
or tmpmax != (pid_t)tmpmax){
197
/* Not a process */
198
errno = 0;
199
continue;
200
}
201
pid = (pid_t)tmpmax;
202
}
203
/* Find the executable name by doing readlink() on the
204
/proc/<pid>/exe link */
205
char exe_target[sizeof(usplash_name)];
206
{
207
/* create file name string */
208
char *exe_link;
209
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
210
if(ret == -1){
211
error_plus(0, errno, "asprintf");
212
goto fail_find_usplash;
213
}
214
215
/* Check that it refers to a symlink owned by root:root */
216
struct stat exe_stat;
217
ret = lstat(exe_link, &exe_stat);
218
if(ret == -1){
219
if(errno == ENOENT){
220
free(exe_link);
221
continue;
222
}
223
error_plus(0, errno, "lstat");
224
free(exe_link);
225
goto fail_find_usplash;
226
}
227
if(not S_ISLNK(exe_stat.st_mode)
228
or exe_stat.st_uid != 0
229
or exe_stat.st_gid != 0){
230
free(exe_link);
231
continue;
232
}
233
234
sret = readlink(exe_link, exe_target, sizeof(exe_target));
235
free(exe_link);
236
}
237
/* Compare executable name */
238
if((sret != ((ssize_t)sizeof(exe_target)-1))
239
or (memcmp(usplash_name, exe_target,
240
sizeof(exe_target)-1) != 0)){
241
/* Not it */
242
continue;
243
}
244
/* Found usplash */
245
/* Read and save the command line of usplash in "cmdline" */
246
{
247
/* Open /proc/<pid>/cmdline */
248
int cl_fd;
249
{
250
char *cmdline_filename;
251
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
252
proc_ent->d_name);
253
if(ret == -1){
254
error_plus(0, errno, "asprintf");
255
goto fail_find_usplash;
256
}
257
cl_fd = open(cmdline_filename, O_RDONLY);
258
free(cmdline_filename);
259
if(cl_fd == -1){
260
error_plus(0, errno, "open");
261
goto fail_find_usplash;
262
}
263
}
264
size_t cmdline_allocated = 0;
265
char *tmp;
266
const size_t blocksize = 1024;
267
do {
268
/* Allocate more space? */
269
if(cmdline_len + blocksize > cmdline_allocated){
270
tmp = realloc(cmdline, cmdline_allocated + blocksize);
271
if(tmp == NULL){
272
error_plus(0, errno, "realloc");
273
close(cl_fd);
274
goto fail_find_usplash;
275
}
276
cmdline = tmp;
277
cmdline_allocated += blocksize;
278
}
279
/* Read data */
280
sret = read(cl_fd, cmdline + cmdline_len,
281
cmdline_allocated - cmdline_len);
282
if(sret == -1){
283
error_plus(0, errno, "read");
284
close(cl_fd);
285
goto fail_find_usplash;
286
}
287
cmdline_len += (size_t)sret;
288
} while(sret != 0);
289
ret = close(cl_fd);
290
if(ret == -1){
291
error_plus(0, errno, "close");
292
goto fail_find_usplash;
293
}
294
}
295
/* Close directory */
296
ret = closedir(proc_dir);
297
if(ret == -1){
298
error_plus(0, errno, "closedir");
299
goto fail_find_usplash;
300
}
301
/* Success */
302
*cmdline_r = cmdline;
303
*cmdline_len_r = cmdline_len;
304
return pid;
305
}
306
307
fail_find_usplash:
308
309
free(cmdline);
310
if(proc_dir != NULL){
311
int e = errno;
312
closedir(proc_dir);
313
errno = e;
314
}
315
return 0;
316
}
317
318
int main(__attribute__((unused))int argc,
319
__attribute__((unused))char **argv){
320
int ret = 0;
321
ssize_t sret;
322
int fifo_fd = -1;
323
int outfifo_fd = -1;
324
char *buf = NULL;
325
size_t buf_len = 0;
326
pid_t usplash_pid = -1;
327
bool usplash_accessed = false;
328
int status = EXIT_FAILURE; /* Default failure exit status */
329
330
char *prompt = makeprompt();
331
if(prompt == NULL){
332
status = EX_OSERR;
333
goto failure;
334
}
335
336
/* Find usplash process */
337
char *cmdline = NULL;
338
size_t cmdline_len = 0;
339
usplash_pid = find_usplash(&cmdline, &cmdline_len);
340
if(usplash_pid == 0){
341
status = EX_UNAVAILABLE;
342
goto failure;
343
}
344
345
/* Set up the signal handler */
346
{
347
struct sigaction old_action,
348
new_action = { .sa_handler = termination_handler,
349
.sa_flags = 0 };
350
sigemptyset(&new_action.sa_mask);
351
ret = sigaddset(&new_action.sa_mask, SIGINT);
352
if(ret == -1){
353
error_plus(0, errno, "sigaddset");
354
status = EX_OSERR;
355
goto failure;
356
}
357
ret = sigaddset(&new_action.sa_mask, SIGHUP);
358
if(ret == -1){
359
error_plus(0, errno, "sigaddset");
360
status = EX_OSERR;
361
goto failure;
362
}
363
ret = sigaddset(&new_action.sa_mask, SIGTERM);
364
if(ret == -1){
365
error_plus(0, errno, "sigaddset");
366
status = EX_OSERR;
367
goto failure;
368
}
369
ret = sigaction(SIGINT, NULL, &old_action);
370
if(ret == -1){
371
if(errno != EINTR){
372
error_plus(0, errno, "sigaction");
373
status = EX_OSERR;
374
}
375
goto failure;
376
}
377
if(old_action.sa_handler != SIG_IGN){
378
ret = sigaction(SIGINT, &new_action, NULL);
379
if(ret == -1){
380
if(errno != EINTR){
381
error_plus(0, errno, "sigaction");
382
status = EX_OSERR;
383
}
384
goto failure;
385
}
386
}
387
ret = sigaction(SIGHUP, NULL, &old_action);
388
if(ret == -1){
389
if(errno != EINTR){
390
error_plus(0, errno, "sigaction");
391
status = EX_OSERR;
392
}
393
goto failure;
394
}
395
if(old_action.sa_handler != SIG_IGN){
396
ret = sigaction(SIGHUP, &new_action, NULL);
397
if(ret == -1){
398
if(errno != EINTR){
399
error_plus(0, errno, "sigaction");
400
status = EX_OSERR;
401
}
402
goto failure;
403
}
404
}
405
ret = sigaction(SIGTERM, NULL, &old_action);
406
if(ret == -1){
407
if(errno != EINTR){
408
error_plus(0, errno, "sigaction");
409
status = EX_OSERR;
410
}
411
goto failure;
412
}
413
if(old_action.sa_handler != SIG_IGN){
414
ret = sigaction(SIGTERM, &new_action, NULL);
415
if(ret == -1){
416
if(errno != EINTR){
417
error_plus(0, errno, "sigaction");
418
status = EX_OSERR;
419
}
420
goto failure;
421
}
422
}
423
}
424
425
usplash_accessed = true;
426
/* Write command to FIFO */
427
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
428
if(errno != EINTR){
429
error_plus(0, errno, "usplash_write");
430
status = EX_OSERR;
431
}
432
goto failure;
433
}
434
435
if(interrupted_by_signal){
436
goto failure;
437
}
438
439
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
440
if(errno != EINTR){
441
error_plus(0, errno, "usplash_write");
442
status = EX_OSERR;
443
}
444
goto failure;
445
}
446
447
if(interrupted_by_signal){
448
goto failure;
449
}
450
451
free(prompt);
452
prompt = NULL;
453
454
/* Read reply from usplash */
455
/* Open FIFO */
456
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
457
if(outfifo_fd == -1){
458
if(errno != EINTR){
459
error_plus(0, errno, "open");
460
status = EX_OSERR;
461
}
462
goto failure;
463
}
464
465
if(interrupted_by_signal){
466
goto failure;
467
}
468
469
/* Read from FIFO */
470
size_t buf_allocated = 0;
471
const size_t blocksize = 1024;
472
do {
473
/* Allocate more space */
474
if(buf_len + blocksize > buf_allocated){
475
char *tmp = realloc(buf, buf_allocated + blocksize);
476
if(tmp == NULL){
477
if(errno != EINTR){
478
error_plus(0, errno, "realloc");
479
status = EX_OSERR;
480
}
481
goto failure;
482
}
483
buf = tmp;
484
buf_allocated += blocksize;
485
}
486
sret = read(outfifo_fd, buf + buf_len,
487
buf_allocated - buf_len);
488
if(sret == -1){
489
if(errno != EINTR){
490
error_plus(0, errno, "read");
491
status = EX_OSERR;
492
}
493
TEMP_FAILURE_RETRY(close(outfifo_fd));
494
goto failure;
495
}
496
if(interrupted_by_signal){
497
break;
498
}
499
500
buf_len += (size_t)sret;
501
} while(sret != 0);
502
ret = close(outfifo_fd);
503
if(ret == -1){
504
if(errno != EINTR){
505
error_plus(0, errno, "close");
506
status = EX_OSERR;
507
}
508
goto failure;
509
}
510
outfifo_fd = -1;
511
512
if(interrupted_by_signal){
513
goto failure;
514
}
515
516
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
517
if(errno != EINTR){
518
error_plus(0, errno, "usplash_write");
519
status = EX_OSERR;
520
}
521
goto failure;
522
}
523
524
if(interrupted_by_signal){
525
goto failure;
526
}
527
528
ret = close(fifo_fd);
529
if(ret == -1){
530
if(errno != EINTR){
531
error_plus(0, errno, "close");
532
status = EX_OSERR;
533
}
534
goto failure;
535
}
536
fifo_fd = -1;
537
538
/* Print password to stdout */
539
size_t written = 0;
540
while(written < buf_len){
541
do {
542
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
543
if(sret == -1){
544
if(errno != EINTR){
545
error_plus(0, errno, "write");
546
status = EX_OSERR;
547
}
548
goto failure;
549
}
550
} while(sret == -1);
551
552
if(interrupted_by_signal){
553
goto failure;
554
}
555
written += (size_t)sret;
556
}
557
free(buf);
558
buf = NULL;
559
560
if(interrupted_by_signal){
561
goto failure;
562
}
563
564
free(cmdline);
565
return EXIT_SUCCESS;
566
567
failure:
568
569
free(buf);
570
571
free(prompt);
572
573
/* If usplash was never accessed, we can stop now */
574
if(not usplash_accessed){
575
return status;
576
}
577
578
/* Close FIFO */
579
if(fifo_fd != -1){
580
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
581
if(ret == -1 and errno != EINTR){
582
error_plus(0, errno, "close");
583
}
584
fifo_fd = -1;
585
}
586
587
/* Close output FIFO */
588
if(outfifo_fd != -1){
589
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
590
if(ret == -1){
591
error_plus(0, errno, "close");
592
}
593
}
594
595
/* Create argv for new usplash*/
596
char **cmdline_argv = malloc((argz_count(cmdline, cmdline_len) + 1)
597
* sizeof(char *)); /* Count args */
598
if(cmdline_argv == NULL){
599
error_plus(0, errno, "malloc");
600
return status;
601
}
602
argz_extract(cmdline, cmdline_len, cmdline_argv); /* Create argv */
603
604
/* Kill old usplash */
605
kill(usplash_pid, SIGTERM);
606
sleep(2);
607
while(kill(usplash_pid, 0) == 0){
608
kill(usplash_pid, SIGKILL);
609
sleep(1);
610
}
611
612
pid_t new_usplash_pid = fork();
613
if(new_usplash_pid == 0){
614
/* Child; will become new usplash process */
615
616
/* Make the effective user ID (root) the only user ID instead of
617
the real user ID (_mandos) */
618
ret = setuid(geteuid());
619
if(ret == -1){
620
error_plus(0, errno, "setuid");
621
}
622
623
setsid();
624
ret = chdir("/");
625
if(ret == -1){
626
error_plus(0, errno, "chdir");
627
_exit(EX_OSERR);
628
}
629
/* if(fork() != 0){ */
630
/* _exit(EXIT_SUCCESS); */
631
/* } */
632
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
633
if(ret == -1){
634
error_plus(0, errno, "dup2");
635
_exit(EX_OSERR);
636
}
637
638
execv(usplash_name, cmdline_argv);
639
if(not interrupted_by_signal){
640
error_plus(0, errno, "execv");
641
}
642
free(cmdline);
643
free(cmdline_argv);
644
_exit(EX_OSERR);
645
}
646
free(cmdline);
647
free(cmdline_argv);
648
sleep(2);
649
if(not usplash_write(&fifo_fd, "PULSATE", NULL)){
650
if(errno != EINTR){
651
error_plus(0, errno, "usplash_write");
652
}
653
}
654
655
/* Close FIFO (again) */
656
if(fifo_fd != -1){
657
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
658
if(ret == -1 and errno != EINTR){
659
error_plus(0, errno, "close");
660
}
661
fifo_fd = -1;
662
}
663
664
if(interrupted_by_signal){
665
struct sigaction signal_action = { .sa_handler = SIG_DFL };
666
sigemptyset(&signal_action.sa_mask);
667
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
668
&signal_action, NULL));
669
if(ret == -1){
670
error_plus(0, errno, "sigaction");
671
}
672
do {
673
ret = raise(signal_received);
674
} while(ret != 0 and errno == EINTR);
675
if(ret != 0){
676
error_plus(0, errno, "raise");
677
abort();
678
}
679
TEMP_FAILURE_RETRY(pause());
680
}
681
682
return status;
683
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0