3
3
* Password-prompt - Read a password from the terminal and print it
5
* Copyright © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
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.
13
* This program is distributed in the hope that it will be useful, but
5
* Copyright © 2008-2017 Teddy Hogeborn
6
* Copyright © 2008-2017 Björn Påhlsson
8
* This file is part of Mandos.
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.
15
* Mandos is distributed in the hope that it will be useful, but
14
16
* WITHOUT ANY WARRANTY; without even the implied warranty of
15
17
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16
18
* General Public License for more details.
18
20
* 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
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
23
* Contact the authors at <mandos@recompile.se>.
25
#define _GNU_SOURCE /* getline() */
26
#define _GNU_SOURCE /* getline(), asprintf() */
27
#include <termios.h> /* struct termios, tcsetattr(),
28
#include <termios.h> /* struct termios, tcsetattr(),
28
29
TCSAFLUSH, tcgetattr(), ECHO */
29
30
#include <unistd.h> /* struct termios, tcsetattr(),
30
31
STDIN_FILENO, TCSAFLUSH,
32
tcgetattr(), ECHO, readlink() */
32
33
#include <signal.h> /* sig_atomic_t, raise(), struct
33
34
sigaction, sigemptyset(),
34
35
sigaction(), sigaddset(), SIGINT,
35
36
SIGQUIT, SIGHUP, SIGTERM,
37
38
#include <stddef.h> /* NULL, size_t, ssize_t */
38
#include <sys/types.h> /* ssize_t */
39
#include <sys/types.h> /* ssize_t, struct dirent, pid_t,
39
41
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
40
getopt_long, getenv() */
43
#include <dirent.h> /* scandir(), alphasort() */
41
44
#include <stdio.h> /* fprintf(), stderr, getline(),
42
stdin, feof(), perror(), fputc(),
43
stdout, getopt_long */
44
#include <errno.h> /* errno, EINVAL */
45
stdin, feof(), fputc(), vfprintf(),
47
#include <errno.h> /* errno, EBADF, ENOTTY, EINVAL,
48
EFAULT, EFBIG, EIO, ENOSPC, EINTR
50
#include <error.h> /* error() */
45
51
#include <iso646.h> /* or, not */
46
52
#include <stdbool.h> /* bool, false, true */
47
#include <string.h> /* strlen, rindex, strncmp, strcmp */
53
#include <inttypes.h> /* strtoumax() */
54
#include <sys/stat.h> /* struct stat, lstat(), open() */
55
#include <string.h> /* strlen, rindex, memcmp, strerror()
48
57
#include <argp.h> /* struct argp_option, struct
49
58
argp_state, struct argp,
50
59
argp_parse(), error_t,
51
60
ARGP_KEY_ARG, ARGP_KEY_END,
52
61
ARGP_ERR_UNKNOWN */
62
#include <sysexits.h> /* EX_SOFTWARE, EX_OSERR,
63
EX_UNAVAILABLE, EX_IOERR, EX_OK */
64
#include <fcntl.h> /* open() */
65
#include <stdarg.h> /* va_list, va_start(), ... */
54
67
volatile sig_atomic_t quit_now = 0;
55
68
int signal_received;
56
69
bool debug = false;
57
70
const char *argp_program_version = "password-prompt " VERSION;
58
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
71
const char *argp_program_bug_address = "<mandos@recompile.se>";
73
/* Needed for conflict resolution */
74
const char plymouth_name[] = "plymouthd";
76
/* Function to use when printing errors */
77
__attribute__((format (gnu_printf, 3, 4)))
78
void error_plus(int status, int errnum, const char *formatstring,
84
va_start(ap, formatstring);
85
ret = vasprintf(&text, formatstring, ap);
87
fprintf(stderr, "Mandos plugin %s: ",
88
program_invocation_short_name);
89
vfprintf(stderr, formatstring, ap);
90
fprintf(stderr, ": %s\n", strerror(errnum));
91
error(status, errno, "vasprintf while printing error");
94
fprintf(stderr, "Mandos plugin ");
95
error(status, errnum, "%s", text);
60
99
static void termination_handler(int signum){
65
104
signal_received = signum;
107
bool conflict_detection(void){
109
/* plymouth conflicts with password-prompt since both want to read
110
from the terminal. Password-prompt will exit if it detects
111
plymouth since plymouth performs the same functionality.
113
__attribute__((nonnull))
114
int is_plymouth(const struct dirent *proc_entry){
121
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
123
if(errno != 0 or *tmp != '\0'
124
or proc_id != (uintmax_t)((pid_t)proc_id)){
129
char *cmdline_filename;
130
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
133
error_plus(0, errno, "asprintf");
137
/* Open /proc/<pid>/cmdline */
138
cl_fd = open(cmdline_filename, O_RDONLY);
139
free(cmdline_filename);
142
error_plus(0, errno, "open");
147
char *cmdline = NULL;
149
size_t cmdline_len = 0;
150
size_t cmdline_allocated = 0;
152
const size_t blocksize = 1024;
155
/* Allocate more space? */
156
if(cmdline_len + blocksize + 1 > cmdline_allocated){
157
tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
159
error_plus(0, errno, "realloc");
165
cmdline_allocated += blocksize;
169
sret = read(cl_fd, cmdline + cmdline_len,
170
cmdline_allocated - cmdline_len);
172
error_plus(0, errno, "read");
177
cmdline_len += (size_t)sret;
181
error_plus(0, errno, "close");
185
cmdline[cmdline_len] = '\0'; /* Make sure it is terminated */
187
/* we now have cmdline */
190
char *cmdline_base = strrchr(cmdline, '/');
191
if(cmdline_base != NULL){
192
cmdline_base += 1; /* skip the slash */
194
cmdline_base = cmdline;
197
if(strcmp(cmdline_base, plymouth_name) != 0){
199
fprintf(stderr, "\"%s\" is not \"%s\"\n", cmdline_base,
206
fprintf(stderr, "\"%s\" equals \"%s\"\n", cmdline_base,
213
struct dirent **direntries = NULL;
215
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
217
error_plus(1, errno, "scandir");
68
230
int main(int argc, char **argv){
71
234
struct termios t_new, t_old;
72
235
char *buffer = NULL;
271
* These reproduce what we would get without ARGP_NO_HELP
273
case '?': /* --help */
274
argp_state_help(state, state->out_stream,
275
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
276
& ~(unsigned int)ARGP_HELP_EXIT_OK);
277
case -3: /* --usage */
278
argp_state_help(state, state->out_stream,
279
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
280
case 'V': /* --version */
281
fprintf(state->out_stream, "%s\n", argp_program_version);
282
exit(argp_err_exit_status);
102
285
return ARGP_ERR_UNKNOWN;
107
290
struct argp argp = { .options = options, .parser = parse_opt,
109
292
.doc = "Mandos password-prompt -- Read and"
110
293
" output a password" };
111
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
112
if(ret == ARGP_ERR_UNKNOWN){
113
fprintf(stderr, "Unknown error while parsing arguments\n");
294
ret = argp_parse(&argp, argc, argv,
295
ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
302
error_plus(0, errno, "argp_parse");
119
310
fprintf(stderr, "Starting %s\n", argv[0]);
313
if(conflict_detection()){
315
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
122
321
fprintf(stderr, "Storing current terminal attributes\n");
125
324
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
326
error_plus(0, errno, "tcgetattr");
330
return EX_UNAVAILABLE;
130
336
sigemptyset(&new_action.sa_mask);
131
337
ret = sigaddset(&new_action.sa_mask, SIGINT);
339
error_plus(0, errno, "sigaddset");
136
342
ret = sigaddset(&new_action.sa_mask, SIGHUP);
344
error_plus(0, errno, "sigaddset");
141
347
ret = sigaddset(&new_action.sa_mask, SIGTERM);
349
error_plus(0, errno, "sigaddset");
146
352
/* Need to check if the handler is SIG_IGN before handling:
147
353
| [[info:libc:Initial Signal Actions]] |
150
356
ret = sigaction(SIGINT, NULL, &old_action);
358
error_plus(0, errno, "sigaction");
155
361
if(old_action.sa_handler != SIG_IGN){
156
362
ret = sigaction(SIGINT, &new_action, NULL);
364
error_plus(0, errno, "sigaction");
162
368
ret = sigaction(SIGHUP, NULL, &old_action);
370
error_plus(0, errno, "sigaction");
167
373
if(old_action.sa_handler != SIG_IGN){
168
374
ret = sigaction(SIGHUP, &new_action, NULL);
376
error_plus(0, errno, "sigaction");
174
380
ret = sigaction(SIGTERM, NULL, &old_action);
382
error_plus(0, errno, "sigaction");
179
385
if(old_action.sa_handler != SIG_IGN){
180
386
ret = sigaction(SIGTERM, &new_action, NULL);
388
error_plus(0, errno, "sigaction");
212
426
fprintf(stderr, "%s ", prefix);
215
const char *cryptsource = getenv("cryptsource");
216
const char *crypttarget = getenv("crypttarget");
217
const char *const prompt
218
= "Enter passphrase to unlock the disk";
429
const char *cryptsource = getenv("CRYPTTAB_SOURCE");
430
const char *crypttarget = getenv("CRYPTTAB_NAME");
431
/* Before cryptsetup 1.1.0~rc2 */
432
if(cryptsource == NULL){
433
cryptsource = getenv("cryptsource");
435
if(crypttarget == NULL){
436
crypttarget = getenv("crypttarget");
438
const char *const prompt1 = "Unlocking the disk";
439
const char *const prompt2 = "Enter passphrase";
219
440
if(cryptsource == NULL){
220
441
if(crypttarget == NULL){
221
fprintf(stderr, "%s: ", prompt);
442
fprintf(stderr, "%s to unlock the disk: ", prompt2);
223
fprintf(stderr, "%s (%s): ", prompt, crypttarget);
444
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
226
448
if(crypttarget == NULL){
227
fprintf(stderr, "%s %s: ", prompt, cryptsource);
449
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
229
fprintf(stderr, "%s %s (%s): ", prompt, cryptsource,
452
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
453
crypttarget, prompt2);
234
ret = getline(&buffer, &n, stdin);
457
sret = getline(&buffer, &n, stdin);
236
459
status = EXIT_SUCCESS;
237
460
/* Make n = data size instead of allocated buffer size */
239
462
/* Strip final newline */
240
if(n>0 and buffer[n-1] == '\n'){
463
if(n > 0 and buffer[n-1] == '\n'){
241
464
buffer[n-1] = '\0'; /* not strictly necessary */
244
467
size_t written = 0;
245
468
while(written < n){
246
ret = write(STDOUT_FILENO, buffer + written, n - written);
249
status = EXIT_FAILURE;
252
written += (size_t)ret;
469
sret = write(STDOUT_FILENO, buffer + written, n - written);
472
error_plus(0, errno, "write");
484
status = EXIT_FAILURE;
489
written += (size_t)sret;
491
sret = close(STDOUT_FILENO);
494
error_plus(0, errno, "close");
257
509
if(errno != EINTR and not feof(stdin)){
259
status = EXIT_FAILURE;
510
error_plus(0, errno, "getline");
513
status = EX_UNAVAILABLE;
263
/* if(ret == 0), then the only sensible thing to do is to retry to
524
/* if(sret == 0), then the only sensible thing to do is to retry
525
to read from stdin */
265
526
fputc('\n', stderr);
266
527
if(debug and not quit_now){
267
528
/* If quit_now is nonzero, we were interrupted by a signal, and