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- Committer: Björn Påhlsson
- Date: 2008-07-20 03:51:41 UTC
- Revision ID: belorn@braxen-20080720035141-ta0y0be7fotdm4ks
Fixed a overbufferflow bug, thanks to a forgotten \0
- files added:
- ca.pem
- files removed:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- debian/upstream
- network-hooks.d
- plugin-helpers
- 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 © 2008-2017 Teddy Hogeborn
6
* Copyright © 2008-2017 Björn Påhlsson
7
*
8
* This file is part of Mandos.
9
*
10
* Mandos is free software: you can redistribute it and/or modify it
11
* under the terms of the GNU General Public License as published by
12
* the Free Software Foundation, either version 3 of the License, or
13
* (at your option) any later version.
14
*
15
* Mandos is distributed in the hope that it will be useful, but
16
* WITHOUT ANY WARRANTY; without even the implied warranty of
17
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18
* General Public License for more details.
19
*
20
* You should have received a copy of the GNU General Public License
21
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
22
*
23
* Contact the authors at <mandos@recompile.se>.
24
*/
25
26
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
27
#include <signal.h> /* sig_atomic_t, struct sigaction,
28
sigemptyset(), sigaddset(), SIGINT,
29
SIGHUP, SIGTERM, sigaction(),
30
SIG_IGN, kill(), SIGKILL */
31
#include <stdbool.h> /* bool, false, true */
32
#include <fcntl.h> /* open(), O_WRONLY, O_RDONLY */
33
#include <iso646.h> /* and, or, not*/
34
#include <errno.h> /* errno, EINTR */
35
#include <error.h>
36
#include <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
37
dirent */
38
#include <stddef.h> /* NULL */
39
#include <string.h> /* strlen(), memcmp(), strerror() */
40
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(),
41
fprintf() */
42
#include <unistd.h> /* close(), write(), readlink(),
43
read(), STDOUT_FILENO, sleep(),
44
fork(), setuid(), geteuid(),
45
setsid(), chdir(), dup2(),
46
STDERR_FILENO, execv() */
47
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
48
EXIT_SUCCESS, malloc(), _exit(),
49
getenv() */
50
#include <dirent.h> /* opendir(), readdir(), closedir() */
51
#include <inttypes.h> /* intmax_t, strtoimax() */
52
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
53
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
54
#include <argz.h> /* argz_count(), argz_extract() */
55
#include <stdarg.h> /* va_list, va_start(), ... */
56
57
sig_atomic_t interrupted_by_signal = 0;
58
int signal_received;
59
const char usplash_name[] = "/sbin/usplash";
60
61
/* Function to use when printing errors */
62
__attribute__((format (gnu_printf, 3, 4)))
63
void error_plus(int status, int errnum, const char *formatstring,
64
...){
65
va_list ap;
66
char *text;
67
int ret;
68
69
va_start(ap, formatstring);
70
ret = vasprintf(&text, formatstring, ap);
71
if(ret == -1){
72
fprintf(stderr, "Mandos plugin %s: ",
73
program_invocation_short_name);
74
vfprintf(stderr, formatstring, ap);
75
fprintf(stderr, ": ");
76
fprintf(stderr, "%s\n", strerror(errnum));
77
error(status, errno, "vasprintf while printing error");
78
return;
79
}
80
fprintf(stderr, "Mandos plugin ");
81
error(status, errnum, "%s", text);
82
free(text);
83
}
84
85
static void termination_handler(int signum){
86
if(interrupted_by_signal){
87
return;
88
}
89
interrupted_by_signal = 1;
90
signal_received = signum;
91
}
92
93
static bool usplash_write(int *fifo_fd_r,
94
const char *cmd, const char *arg){
95
/*
96
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
97
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
98
* SEE ALSO
99
* usplash_write(8)
100
*/
101
int ret;
102
if(*fifo_fd_r == -1){
103
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
104
if(ret == -1){
105
return false;
106
}
107
*fifo_fd_r = ret;
108
}
109
110
const char *cmd_line;
111
size_t cmd_line_len;
112
char *cmd_line_alloc = NULL;
113
if(arg == NULL){
114
cmd_line = cmd;
115
cmd_line_len = strlen(cmd) + 1;
116
} else {
117
do {
118
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
119
if(ret == -1){
120
int e = errno;
121
close(*fifo_fd_r);
122
errno = e;
123
return false;
124
}
125
} while(ret == -1);
126
cmd_line = cmd_line_alloc;
127
cmd_line_len = (size_t)ret + 1;
128
}
129
130
size_t written = 0;
131
ssize_t sret = 0;
132
while(written < cmd_line_len){
133
sret = write(*fifo_fd_r, cmd_line + written,
134
cmd_line_len - written);
135
if(sret == -1){
136
int e = errno;
137
close(*fifo_fd_r);
138
free(cmd_line_alloc);
139
errno = e;
140
return false;
141
}
142
written += (size_t)sret;
143
}
144
free(cmd_line_alloc);
145
146
return true;
147
}
148
149
/* Create prompt string */
150
char *makeprompt(void){
151
int ret = 0;
152
char *prompt;
153
const char *const cryptsource = getenv("cryptsource");
154
const char *const crypttarget = getenv("crypttarget");
155
const char prompt_start[] = "Enter passphrase to unlock the disk";
156
157
if(cryptsource == NULL){
158
if(crypttarget == NULL){
159
ret = asprintf(&prompt, "%s: ", prompt_start);
160
} else {
161
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
162
crypttarget);
163
}
164
} else {
165
if(crypttarget == NULL){
166
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
167
} else {
168
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
169
cryptsource, crypttarget);
170
}
171
}
172
if(ret == -1){
173
return NULL;
174
}
175
return prompt;
176
}
177
178
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
179
int ret = 0;
180
ssize_t sret = 0;
181
char *cmdline = NULL;
182
size_t cmdline_len = 0;
183
DIR *proc_dir = opendir("/proc");
184
if(proc_dir == NULL){
185
error_plus(0, errno, "opendir");
186
return -1;
187
}
188
errno = 0;
189
for(struct dirent *proc_ent = readdir(proc_dir);
190
proc_ent != NULL;
191
proc_ent = readdir(proc_dir)){
192
pid_t pid;
193
{
194
intmax_t tmpmax;
195
char *tmp;
196
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
197
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
198
or tmpmax != (pid_t)tmpmax){
199
/* Not a process */
200
errno = 0;
201
continue;
202
}
203
pid = (pid_t)tmpmax;
204
}
205
/* Find the executable name by doing readlink() on the
206
/proc/<pid>/exe link */
207
char exe_target[sizeof(usplash_name)];
208
{
209
/* create file name string */
210
char *exe_link;
211
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
212
if(ret == -1){
213
error_plus(0, errno, "asprintf");
214
goto fail_find_usplash;
215
}
216
217
/* Check that it refers to a symlink owned by root:root */
218
struct stat exe_stat;
219
ret = lstat(exe_link, &exe_stat);
220
if(ret == -1){
221
if(errno == ENOENT){
222
free(exe_link);
223
continue;
224
}
225
error_plus(0, errno, "lstat");
226
free(exe_link);
227
goto fail_find_usplash;
228
}
229
if(not S_ISLNK(exe_stat.st_mode)
230
or exe_stat.st_uid != 0
231
or exe_stat.st_gid != 0){
232
free(exe_link);
233
continue;
234
}
235
236
sret = readlink(exe_link, exe_target, sizeof(exe_target));
237
free(exe_link);
238
}
239
/* Compare executable name */
240
if((sret != ((ssize_t)sizeof(exe_target)-1))
241
or (memcmp(usplash_name, exe_target,
242
sizeof(exe_target)-1) != 0)){
243
/* Not it */
244
continue;
245
}
246
/* Found usplash */
247
/* Read and save the command line of usplash in "cmdline" */
248
{
249
/* Open /proc/<pid>/cmdline */
250
int cl_fd;
251
{
252
char *cmdline_filename;
253
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
254
proc_ent->d_name);
255
if(ret == -1){
256
error_plus(0, errno, "asprintf");
257
goto fail_find_usplash;
258
}
259
cl_fd = open(cmdline_filename, O_RDONLY);
260
free(cmdline_filename);
261
if(cl_fd == -1){
262
error_plus(0, errno, "open");
263
goto fail_find_usplash;
264
}
265
}
266
size_t cmdline_allocated = 0;
267
char *tmp;
268
const size_t blocksize = 1024;
269
do {
270
/* Allocate more space? */
271
if(cmdline_len + blocksize > cmdline_allocated){
272
tmp = realloc(cmdline, cmdline_allocated + blocksize);
273
if(tmp == NULL){
274
error_plus(0, errno, "realloc");
275
close(cl_fd);
276
goto fail_find_usplash;
277
}
278
cmdline = tmp;
279
cmdline_allocated += blocksize;
280
}
281
/* Read data */
282
sret = read(cl_fd, cmdline + cmdline_len,
283
cmdline_allocated - cmdline_len);
284
if(sret == -1){
285
error_plus(0, errno, "read");
286
close(cl_fd);
287
goto fail_find_usplash;
288
}
289
cmdline_len += (size_t)sret;
290
} while(sret != 0);
291
ret = close(cl_fd);
292
if(ret == -1){
293
error_plus(0, errno, "close");
294
goto fail_find_usplash;
295
}
296
}
297
/* Close directory */
298
ret = closedir(proc_dir);
299
if(ret == -1){
300
error_plus(0, errno, "closedir");
301
goto fail_find_usplash;
302
}
303
/* Success */
304
*cmdline_r = cmdline;
305
*cmdline_len_r = cmdline_len;
306
return pid;
307
}
308
309
fail_find_usplash:
310
311
free(cmdline);
312
if(proc_dir != NULL){
313
int e = errno;
314
closedir(proc_dir);
315
errno = e;
316
}
317
return 0;
318
}
319
320
int main(__attribute__((unused))int argc,
321
__attribute__((unused))char **argv){
322
int ret = 0;
323
ssize_t sret;
324
int fifo_fd = -1;
325
int outfifo_fd = -1;
326
char *buf = NULL;
327
size_t buf_len = 0;
328
pid_t usplash_pid = -1;
329
bool usplash_accessed = false;
330
int status = EXIT_FAILURE; /* Default failure exit status */
331
332
char *prompt = makeprompt();
333
if(prompt == NULL){
334
status = EX_OSERR;
335
goto failure;
336
}
337
338
/* Find usplash process */
339
char *cmdline = NULL;
340
size_t cmdline_len = 0;
341
usplash_pid = find_usplash(&cmdline, &cmdline_len);
342
if(usplash_pid == 0){
343
status = EX_UNAVAILABLE;
344
goto failure;
345
}
346
347
/* Set up the signal handler */
348
{
349
struct sigaction old_action,
350
new_action = { .sa_handler = termination_handler,
351
.sa_flags = 0 };
352
sigemptyset(&new_action.sa_mask);
353
ret = sigaddset(&new_action.sa_mask, SIGINT);
354
if(ret == -1){
355
error_plus(0, errno, "sigaddset");
356
status = EX_OSERR;
357
goto failure;
358
}
359
ret = sigaddset(&new_action.sa_mask, SIGHUP);
360
if(ret == -1){
361
error_plus(0, errno, "sigaddset");
362
status = EX_OSERR;
363
goto failure;
364
}
365
ret = sigaddset(&new_action.sa_mask, SIGTERM);
366
if(ret == -1){
367
error_plus(0, errno, "sigaddset");
368
status = EX_OSERR;
369
goto failure;
370
}
371
ret = sigaction(SIGINT, NULL, &old_action);
372
if(ret == -1){
373
if(errno != EINTR){
374
error_plus(0, errno, "sigaction");
375
status = EX_OSERR;
376
}
377
goto failure;
378
}
379
if(old_action.sa_handler != SIG_IGN){
380
ret = sigaction(SIGINT, &new_action, NULL);
381
if(ret == -1){
382
if(errno != EINTR){
383
error_plus(0, errno, "sigaction");
384
status = EX_OSERR;
385
}
386
goto failure;
387
}
388
}
389
ret = sigaction(SIGHUP, NULL, &old_action);
390
if(ret == -1){
391
if(errno != EINTR){
392
error_plus(0, errno, "sigaction");
393
status = EX_OSERR;
394
}
395
goto failure;
396
}
397
if(old_action.sa_handler != SIG_IGN){
398
ret = sigaction(SIGHUP, &new_action, NULL);
399
if(ret == -1){
400
if(errno != EINTR){
401
error_plus(0, errno, "sigaction");
402
status = EX_OSERR;
403
}
404
goto failure;
405
}
406
}
407
ret = sigaction(SIGTERM, NULL, &old_action);
408
if(ret == -1){
409
if(errno != EINTR){
410
error_plus(0, errno, "sigaction");
411
status = EX_OSERR;
412
}
413
goto failure;
414
}
415
if(old_action.sa_handler != SIG_IGN){
416
ret = sigaction(SIGTERM, &new_action, NULL);
417
if(ret == -1){
418
if(errno != EINTR){
419
error_plus(0, errno, "sigaction");
420
status = EX_OSERR;
421
}
422
goto failure;
423
}
424
}
425
}
426
427
usplash_accessed = true;
428
/* Write command to FIFO */
429
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
430
if(errno != EINTR){
431
error_plus(0, errno, "usplash_write");
432
status = EX_OSERR;
433
}
434
goto failure;
435
}
436
437
if(interrupted_by_signal){
438
goto failure;
439
}
440
441
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
442
if(errno != EINTR){
443
error_plus(0, errno, "usplash_write");
444
status = EX_OSERR;
445
}
446
goto failure;
447
}
448
449
if(interrupted_by_signal){
450
goto failure;
451
}
452
453
free(prompt);
454
prompt = NULL;
455
456
/* Read reply from usplash */
457
/* Open FIFO */
458
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
459
if(outfifo_fd == -1){
460
if(errno != EINTR){
461
error_plus(0, errno, "open");
462
status = EX_OSERR;
463
}
464
goto failure;
465
}
466
467
if(interrupted_by_signal){
468
goto failure;
469
}
470
471
/* Read from FIFO */
472
size_t buf_allocated = 0;
473
const size_t blocksize = 1024;
474
do {
475
/* Allocate more space */
476
if(buf_len + blocksize > buf_allocated){
477
char *tmp = realloc(buf, buf_allocated + blocksize);
478
if(tmp == NULL){
479
if(errno != EINTR){
480
error_plus(0, errno, "realloc");
481
status = EX_OSERR;
482
}
483
goto failure;
484
}
485
buf = tmp;
486
buf_allocated += blocksize;
487
}
488
sret = read(outfifo_fd, buf + buf_len,
489
buf_allocated - buf_len);
490
if(sret == -1){
491
if(errno != EINTR){
492
error_plus(0, errno, "read");
493
status = EX_OSERR;
494
}
495
close(outfifo_fd);
496
goto failure;
497
}
498
if(interrupted_by_signal){
499
break;
500
}
501
502
buf_len += (size_t)sret;
503
} while(sret != 0);
504
ret = close(outfifo_fd);
505
if(ret == -1){
506
if(errno != EINTR){
507
error_plus(0, errno, "close");
508
status = EX_OSERR;
509
}
510
goto failure;
511
}
512
outfifo_fd = -1;
513
514
if(interrupted_by_signal){
515
goto failure;
516
}
517
518
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
519
if(errno != EINTR){
520
error_plus(0, errno, "usplash_write");
521
status = EX_OSERR;
522
}
523
goto failure;
524
}
525
526
if(interrupted_by_signal){
527
goto failure;
528
}
529
530
ret = close(fifo_fd);
531
if(ret == -1){
532
if(errno != EINTR){
533
error_plus(0, errno, "close");
534
status = EX_OSERR;
535
}
536
goto failure;
537
}
538
fifo_fd = -1;
539
540
/* Print password to stdout */
541
size_t written = 0;
542
while(written < buf_len){
543
do {
544
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
545
if(sret == -1){
546
if(errno != EINTR){
547
error_plus(0, errno, "write");
548
status = EX_OSERR;
549
}
550
goto failure;
551
}
552
} while(sret == -1);
553
554
if(interrupted_by_signal){
555
goto failure;
556
}
557
written += (size_t)sret;
558
}
559
free(buf);
560
buf = NULL;
561
562
if(interrupted_by_signal){
563
goto failure;
564
}
565
566
free(cmdline);
567
return EXIT_SUCCESS;
568
569
failure:
570
571
free(buf);
572
573
free(prompt);
574
575
/* If usplash was never accessed, we can stop now */
576
if(not usplash_accessed){
577
return status;
578
}
579
580
/* Close FIFO */
581
if(fifo_fd != -1){
582
ret = close(fifo_fd);
583
if(ret == -1 and errno != EINTR){
584
error_plus(0, errno, "close");
585
}
586
fifo_fd = -1;
587
}
588
589
/* Close output FIFO */
590
if(outfifo_fd != -1){
591
ret = close(outfifo_fd);
592
if(ret == -1){
593
error_plus(0, errno, "close");
594
}
595
}
596
597
/* Create argv for new usplash*/
598
char **cmdline_argv = malloc((argz_count(cmdline, cmdline_len) + 1)
599
* sizeof(char *)); /* Count args */
600
if(cmdline_argv == NULL){
601
error_plus(0, errno, "malloc");
602
return status;
603
}
604
argz_extract(cmdline, cmdline_len, cmdline_argv); /* Create argv */
605
606
/* Kill old usplash */
607
kill(usplash_pid, SIGTERM);
608
sleep(2);
609
while(kill(usplash_pid, 0) == 0){
610
kill(usplash_pid, SIGKILL);
611
sleep(1);
612
}
613
614
pid_t new_usplash_pid = fork();
615
if(new_usplash_pid == 0){
616
/* Child; will become new usplash process */
617
618
/* Make the effective user ID (root) the only user ID instead of
619
the real user ID (_mandos) */
620
ret = setuid(geteuid());
621
if(ret == -1){
622
error_plus(0, errno, "setuid");
623
}
624
625
setsid();
626
ret = chdir("/");
627
if(ret == -1){
628
error_plus(0, errno, "chdir");
629
_exit(EX_OSERR);
630
}
631
/* if(fork() != 0){ */
632
/* _exit(EXIT_SUCCESS); */
633
/* } */
634
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
635
if(ret == -1){
636
error_plus(0, errno, "dup2");
637
_exit(EX_OSERR);
638
}
639
640
execv(usplash_name, cmdline_argv);
641
if(not interrupted_by_signal){
642
error_plus(0, errno, "execv");
643
}
644
free(cmdline);
645
free(cmdline_argv);
646
_exit(EX_OSERR);
647
}
648
free(cmdline);
649
free(cmdline_argv);
650
sleep(2);
651
if(not usplash_write(&fifo_fd, "PULSATE", NULL)){
652
if(errno != EINTR){
653
error_plus(0, errno, "usplash_write");
654
}
655
}
656
657
/* Close FIFO (again) */
658
if(fifo_fd != -1){
659
ret = close(fifo_fd);
660
if(ret == -1 and errno != EINTR){
661
error_plus(0, errno, "close");
662
}
663
fifo_fd = -1;
664
}
665
666
if(interrupted_by_signal){
667
struct sigaction signal_action = { .sa_handler = SIG_DFL };
668
sigemptyset(&signal_action.sa_mask);
669
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
670
&signal_action, NULL));
671
if(ret == -1){
672
error_plus(0, errno, "sigaction");
673
}
674
do {
675
ret = raise(signal_received);
676
} while(ret != 0 and errno == EINTR);
677
if(ret != 0){
678
error_plus(0, errno, "raise");
679
abort();
680
}
681
TEMP_FAILURE_RETRY(pause());
682
}
683
684
return status;
685
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0