1
/* -*- coding: utf-8 -*- */
1
/* -*- coding: utf-8; mode: c; mode: orgtbl -*- */
3
* Passprompt - Read a password from the terminal and print it
5
* Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
7
* This program is free software: you can redistribute it and/or
8
* modify it under the terms of the GNU General Public License as
9
* published by the Free Software Foundation, either version 3 of the
10
* License, or (at your option) any later version.
12
* This program is distributed in the hope that it will be useful, but
3
* Password-prompt - Read a password from the terminal and print it
5
* Copyright © 2008-2019 Teddy Hogeborn
6
* Copyright © 2008-2019 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
13
16
* WITHOUT ANY WARRANTY; without even the implied warranty of
14
17
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15
18
* General Public License for more details.
17
20
* You should have received a copy of the GNU General Public License
18
* along with this program. If not, see
19
* <http://www.gnu.org/licenses/>.
21
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
21
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
22
* <https://www.fukt.bsnet.se/~teddy/>.
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
SIGQUIT, SIGHUP, SIGTERM */
36
SIGQUIT, SIGHUP, SIGTERM,
36
38
#include <stddef.h> /* NULL, size_t, ssize_t */
37
#include <sys/types.h> /* ssize_t */
39
#include <sys/types.h> /* ssize_t, struct dirent, pid_t,
38
41
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
43
#include <dirent.h> /* scandir(), alphasort() */
40
44
#include <stdio.h> /* fprintf(), stderr, getline(),
41
stdin, feof(), perror(), fputc(),
42
stdout, getopt_long */
43
#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() */
44
51
#include <iso646.h> /* or, not */
45
52
#include <stdbool.h> /* bool, false, true */
46
#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()
47
57
#include <argp.h> /* struct argp_option, struct
48
58
argp_state, struct argp,
49
59
argp_parse(), error_t,
50
60
ARGP_KEY_ARG, ARGP_KEY_END,
51
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(), ... */
53
volatile bool quit_now = false;
67
volatile sig_atomic_t quit_now = 0;
54
69
bool debug = false;
55
const char *argp_program_version = "passprompt 0.9";
56
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
58
static void termination_handler(__attribute__((unused))int signum){
70
const char *argp_program_version = "password-prompt " VERSION;
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);
99
static void termination_handler(int signum){
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");
62
230
int main(int argc, char **argv){
65
234
struct termios t_new, t_old;
66
235
char *buffer = NULL;
73
242
struct argp_option options[] = {
74
243
{ .name = "prefix", .key = 'p',
75
244
.arg = "PREFIX", .flags = 0,
76
.doc = "Prefix used before the passprompt", .group = 2 },
245
.doc = "Prefix shown before the prompt", .group = 2 },
77
246
{ .name = "debug", .key = 128,
78
247
.doc = "Debug mode", .group = 3 },
249
* These reproduce what we would get without ARGP_NO_HELP
251
{ .name = "help", .key = '?',
252
.doc = "Give this help list", .group = -1 },
253
{ .name = "usage", .key = -3,
254
.doc = "Give a short usage message", .group = -1 },
255
{ .name = "version", .key = 'V',
256
.doc = "Print program version", .group = -1 },
82
error_t parse_opt (int key, char *arg, struct argp_state *state) {
83
/* Get the INPUT argument from `argp_parse', which we know is a
84
pointer to our plugin list pointer. */
260
__attribute__((nonnull(3)))
261
error_t parse_opt (int key, char *arg, struct argp_state *state){
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
__builtin_unreachable();
278
case -3: /* --usage */
279
argp_state_help(state, state->out_stream,
280
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
281
__builtin_unreachable();
282
case 'V': /* --version */
283
fprintf(state->out_stream, "%s\n", argp_program_version);
284
exit(argp_err_exit_status);
98
287
return ARGP_ERR_UNKNOWN;
103
292
struct argp argp = { .options = options, .parser = parse_opt,
105
.doc = "Mandos Passprompt -- Provides a passprompt" };
106
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
107
if (ret == ARGP_ERR_UNKNOWN){
108
perror("argp_parse");
294
.doc = "Mandos password-prompt -- Read and"
295
" output a password" };
296
ret = argp_parse(&argp, argc, argv,
297
ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
304
error_plus(0, errno, "argp_parse");
114
312
fprintf(stderr, "Starting %s\n", argv[0]);
315
if(conflict_detection()){
317
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
117
323
fprintf(stderr, "Storing current terminal attributes\n");
120
if (tcgetattr(STDIN_FILENO, &t_old) != 0){
326
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
328
error_plus(0, errno, "tcgetattr");
332
return EX_UNAVAILABLE;
124
338
sigemptyset(&new_action.sa_mask);
125
sigaddset(&new_action.sa_mask, SIGINT);
126
sigaddset(&new_action.sa_mask, SIGHUP);
127
sigaddset(&new_action.sa_mask, SIGTERM);
339
ret = sigaddset(&new_action.sa_mask, SIGINT);
341
error_plus(0, errno, "sigaddset");
344
ret = sigaddset(&new_action.sa_mask, SIGHUP);
346
error_plus(0, errno, "sigaddset");
349
ret = sigaddset(&new_action.sa_mask, SIGTERM);
351
error_plus(0, errno, "sigaddset");
354
/* Need to check if the handler is SIG_IGN before handling:
355
| [[info:libc:Initial Signal Actions]] |
356
| [[info:libc:Basic Signal Handling]] |
128
358
ret = sigaction(SIGINT, NULL, &old_action);
360
error_plus(0, errno, "sigaction");
133
if (old_action.sa_handler != SIG_IGN){
363
if(old_action.sa_handler != SIG_IGN){
134
364
ret = sigaction(SIGINT, &new_action, NULL);
366
error_plus(0, errno, "sigaction");
140
370
ret = sigaction(SIGHUP, NULL, &old_action);
372
error_plus(0, errno, "sigaction");
145
if (old_action.sa_handler != SIG_IGN){
375
if(old_action.sa_handler != SIG_IGN){
146
376
ret = sigaction(SIGHUP, &new_action, NULL);
378
error_plus(0, errno, "sigaction");
152
382
ret = sigaction(SIGTERM, NULL, &old_action);
384
error_plus(0, errno, "sigaction");
157
if (old_action.sa_handler != SIG_IGN){
387
if(old_action.sa_handler != SIG_IGN){
158
388
ret = sigaction(SIGTERM, &new_action, NULL);
390
error_plus(0, errno, "sigaction");
167
397
fprintf(stderr, "Removing echo flag from terminal attributes\n");
171
t_new.c_lflag &= ~ECHO;
172
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
173
perror("tcsetattr-echo");
401
t_new.c_lflag &= ~(tcflag_t)ECHO;
402
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
404
error_plus(0, errno, "tcsetattr-echo");
408
return EX_UNAVAILABLE;
178
416
fprintf(stderr, "Waiting for input from stdin \n");
421
fprintf(stderr, "Interrupted by signal, exiting.\n");
182
423
status = EXIT_FAILURE;
187
fprintf(stderr, "%s Password: ", prefix);
189
fprintf(stderr, "Password: ");
191
ret = getline(&buffer, &n, stdin);
193
fprintf(stdout, "%s", buffer);
428
fprintf(stderr, "%s ", prefix);
431
const char *cryptsource = getenv("CRYPTTAB_SOURCE");
432
const char *crypttarget = getenv("CRYPTTAB_NAME");
433
/* Before cryptsetup 1.1.0~rc2 */
434
if(cryptsource == NULL){
435
cryptsource = getenv("cryptsource");
437
if(crypttarget == NULL){
438
crypttarget = getenv("crypttarget");
440
const char *const prompt1 = "Unlocking the disk";
441
const char *const prompt2 = "Enter passphrase";
442
if(cryptsource == NULL){
443
if(crypttarget == NULL){
444
fprintf(stderr, "%s to unlock the disk: ", prompt2);
446
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
450
if(crypttarget == NULL){
451
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
454
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
455
crypttarget, prompt2);
459
sret = getline(&buffer, &n, stdin);
194
461
status = EXIT_SUCCESS;
462
/* Make n = data size instead of allocated buffer size */
464
/* Strip final newline */
465
if(n > 0 and buffer[n-1] == '\n'){
466
buffer[n-1] = '\0'; /* not strictly necessary */
471
sret = write(STDOUT_FILENO, buffer + written, n - written);
474
error_plus(0, errno, "write");
486
status = EXIT_FAILURE;
491
written += (size_t)sret;
493
sret = close(STDOUT_FILENO);
496
error_plus(0, errno, "close");
198
if (errno != EINTR and not feof(stdin)){
200
status = EXIT_FAILURE;
511
if(errno != EINTR and not feof(stdin)){
512
error_plus(0, errno, "getline");
515
status = EX_UNAVAILABLE;
204
/* if(ret == 0), then the only sensible thing to do is to retry to
526
/* if(sret == 0), then the only sensible thing to do is to retry
527
to read from stdin */
206
528
fputc('\n', stderr);
529
if(debug and not quit_now){
530
/* If quit_now is nonzero, we were interrupted by a signal, and
531
will print that later, so no need to show this too. */
532
fprintf(stderr, "getline() returned 0, retrying.\n");
210
539
fprintf(stderr, "Restoring terminal attributes\n");
212
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
213
perror("tcsetattr+echo");
217
fprintf(stderr, "%s is exiting\n", argv[0]);
541
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
542
error_plus(0, errno, "tcsetattr+echo");
546
sigemptyset(&old_action.sa_mask);
547
old_action.sa_handler = SIG_DFL;
548
ret = sigaction(signal_received, &old_action, NULL);
550
error_plus(0, errno, "sigaction");
552
raise(signal_received);
556
fprintf(stderr, "%s is exiting with status %d\n", argv[0],
559
if(status == EXIT_SUCCESS or status == EX_OK){