1
/* -*- coding: utf-8; mode: c; mode: orgtbl -*- */
1
/* -*- coding: utf-8 -*- */
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
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
16
13
* WITHOUT ANY WARRANTY; without even the implied warranty of
17
14
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18
15
* General Public License for more details.
20
17
* You should have received a copy of the GNU General Public License
21
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
18
* along with this program. If not, see
19
* <http://www.gnu.org/licenses/>.
23
* Contact the authors at <mandos@recompile.se>.
21
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
22
* <https://www.fukt.bsnet.se/~teddy/>.
26
#define _GNU_SOURCE /* vasprintf(),
27
program_invocation_short_name,
28
asprintf(), getline() */
29
#include <sys/types.h> /* sig_atomic_t, pid_t */
25
#define _GNU_SOURCE /* getline() */
27
#include <termios.h> /* struct termios, tcsetattr(),
28
TCSAFLUSH, tcgetattr(), ECHO */
29
#include <unistd.h> /* struct termios, tcsetattr(),
30
STDIN_FILENO, TCSAFLUSH,
32
#include <signal.h> /* sig_atomic_t, raise(), struct
33
sigaction, sigemptyset(),
34
sigaction(), sigaddset(), SIGINT,
35
SIGQUIT, SIGHUP, SIGTERM */
36
#include <stddef.h> /* NULL, size_t */
37
#include <sys/types.h> /* ssize_t */
38
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
40
#include <stdio.h> /* fprintf(), stderr, getline(),
41
stdin, feof(), perror(), fputc(),
42
stdout, getopt_long */
43
#include <errno.h> /* errno, EINVAL */
44
#include <iso646.h> /* or, not */
30
45
#include <stdbool.h> /* bool, false, true */
31
#include <argp.h> /* argp_program_version,
32
argp_program_bug_address,
34
struct argp_state, argp_state_help,
37
ARGP_HELP_EXIT_OK, ARGP_HELP_USAGE,
39
ARGP_ERR_UNKNOWN, argp_parse(),
40
ARGP_IN_ORDER, ARGP_NO_HELP */
41
#include <stdarg.h> /* va_list, va_start(), vfprintf() */
42
#include <stdio.h> /* vasprintf(), fprintf(), stderr,
43
vfprintf(), asprintf(), getline(),
44
stdin, feof(), clearerr(),
46
#include <errno.h> /* program_invocation_short_name,
47
errno, ENOENT, error_t, ENOMEM,
48
EINVAL, EBADF, ENOTTY, EFAULT,
49
EFBIG, EIO, ENOSPC, EINTR */
50
#include <string.h> /* strerror(), strrchr(), strcmp() */
51
#include <error.h> /* error() */
52
#include <stdlib.h> /* free(), realloc(), EXIT_SUCCESS,
53
EXIT_FAILURE, getenv() */
54
#include <unistd.h> /* access(), R_OK, ssize_t, close(),
55
read(), STDIN_FILENO, write(),
57
#include <dirent.h> /* struct dirent, scandir(),
59
#include <inttypes.h> /* uintmax_t, strtoumax() */
60
#include <iso646.h> /* or, and, not */
61
#include <fcntl.h> /* open(), O_RDONLY */
62
#include <stddef.h> /* NULL, size_t */
63
#include <termios.h> /* struct termios, tcgetattr(),
64
tcflag_t, ECHO, tcsetattr(),
66
#include <signal.h> /* struct sigaction, sigemptyset(),
67
sigaddset(), SIGINT, SIGHUP,
68
SIGTERM, SIG_IGN, SIG_DFL,
70
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
71
EX_IOERR, EX_OSFILE, EX_OK */
46
#include <string.h> /* strlen, rindex, strncmp, strcmp */
47
#include <argp.h> /* struct argp_option,
48
struct argp_state, struct argp,
73
volatile sig_atomic_t quit_now = 0;
51
volatile bool quit_now = false;
75
52
bool debug = false;
76
const char *argp_program_version = "password-prompt " VERSION;
77
const char *argp_program_bug_address = "<mandos@recompile.se>";
79
/* Needed for conflict resolution */
80
const char plymouth_name[] = "plymouthd";
82
/* Function to use when printing errors */
83
__attribute__((format (gnu_printf, 3, 4)))
84
void error_plus(int status, int errnum, const char *formatstring,
90
va_start(ap, formatstring);
91
ret = vasprintf(&text, formatstring, ap);
93
fprintf(stderr, "Mandos plugin %s: ",
94
program_invocation_short_name);
95
vfprintf(stderr, formatstring, ap);
96
fprintf(stderr, ": %s\n", strerror(errnum));
97
error(status, errno, "vasprintf while printing error");
100
fprintf(stderr, "Mandos plugin ");
101
error(status, errnum, "%s", text);
105
static void termination_handler(int signum){
110
signal_received = signum;
113
bool conflict_detection(void){
115
/* plymouth conflicts with password-prompt since both want to read
116
from the terminal. Password-prompt will exit if it detects
117
plymouth since plymouth performs the same functionality.
119
if(access("/run/plymouth/pid", R_OK) == 0){
123
__attribute__((nonnull))
124
int is_plymouth(const struct dirent *proc_entry){
131
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
133
if(errno != 0 or *tmp != '\0'
134
or proc_id != (uintmax_t)((pid_t)proc_id)){
139
char *cmdline_filename;
140
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
143
error_plus(0, errno, "asprintf");
147
/* Open /proc/<pid>/cmdline */
148
cl_fd = open(cmdline_filename, O_RDONLY);
149
free(cmdline_filename);
152
error_plus(0, errno, "open");
157
char *cmdline = NULL;
159
size_t cmdline_len = 0;
160
size_t cmdline_allocated = 0;
162
const size_t blocksize = 1024;
165
/* Allocate more space? */
166
if(cmdline_len + blocksize + 1 > cmdline_allocated){
167
tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
169
error_plus(0, errno, "realloc");
175
cmdline_allocated += blocksize;
179
sret = read(cl_fd, cmdline + cmdline_len,
180
cmdline_allocated - cmdline_len);
182
error_plus(0, errno, "read");
187
cmdline_len += (size_t)sret;
191
error_plus(0, errno, "close");
195
cmdline[cmdline_len] = '\0'; /* Make sure it is terminated */
197
/* we now have cmdline */
200
char *cmdline_base = strrchr(cmdline, '/');
201
if(cmdline_base != NULL){
202
cmdline_base += 1; /* skip the slash */
204
cmdline_base = cmdline;
207
if(strcmp(cmdline_base, plymouth_name) != 0){
209
fprintf(stderr, "\"%s\" is not \"%s\"\n", cmdline_base,
216
fprintf(stderr, "\"%s\" equals \"%s\"\n", cmdline_base,
223
struct dirent **direntries = NULL;
225
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
227
error_plus(1, errno, "scandir");
53
const char *argp_program_version = "passprompt 0.9";
54
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
56
static void termination_handler(__attribute__((unused))int signum){
240
60
int main(int argc, char **argv){
244
63
struct termios t_new, t_old;
245
64
char *buffer = NULL;
246
65
char *prefix = NULL;
248
66
int status = EXIT_SUCCESS;
249
67
struct sigaction old_action,
250
68
new_action = { .sa_handler = termination_handler,
253
71
struct argp_option options[] = {
254
72
{ .name = "prefix", .key = 'p',
255
73
.arg = "PREFIX", .flags = 0,
256
.doc = "Prefix shown before the prompt", .group = 2 },
257
{ .name = "prompt", .key = 129,
258
.arg = "PROMPT", .flags = 0,
259
.doc = "The prompt to show", .group = 2 },
74
.doc = "Prefix used before the passprompt", .group = 2 },
260
75
{ .name = "debug", .key = 128,
261
76
.doc = "Debug mode", .group = 3 },
263
* These reproduce what we would get without ARGP_NO_HELP
265
{ .name = "help", .key = '?',
266
.doc = "Give this help list", .group = -1 },
267
{ .name = "usage", .key = -3,
268
.doc = "Give a short usage message", .group = -1 },
269
{ .name = "version", .key = 'V',
270
.doc = "Print program version", .group = -1 },
274
__attribute__((nonnull(3)))
275
error_t parse_opt (int key, char *arg, struct argp_state *state){
278
case 'p': /* --prefix */
80
error_t parse_opt (int key, char *arg, struct argp_state *state) {
81
/* Get the INPUT argument from `argp_parse', which we know is a
82
pointer to our plugin list pointer. */
281
case 128: /* --debug */
284
case 129: /* --prompt */
288
* These reproduce what we would get without ARGP_NO_HELP
290
case '?': /* --help */
291
argp_state_help(state, state->out_stream,
292
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
293
& ~(unsigned int)ARGP_HELP_EXIT_OK);
294
__builtin_unreachable();
295
case -3: /* --usage */
296
argp_state_help(state, state->out_stream,
297
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
298
__builtin_unreachable();
299
case 'V': /* --version */
300
fprintf(state->out_stream, "%s\n", argp_program_version);
301
exit(argp_err_exit_status);
304
96
return ARGP_ERR_UNKNOWN;
309
101
struct argp argp = { .options = options, .parser = parse_opt,
311
.doc = "Mandos password-prompt -- Read and"
312
" output a password" };
313
ret = argp_parse(&argp, argc, argv,
314
ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
321
error_plus(0, errno, "argp_parse");
103
.doc = "Mandos Passprompt -- Provides a passprompt" };
104
argp_parse (&argp, argc, argv, 0, 0, NULL);
329
108
fprintf(stderr, "Starting %s\n", argv[0]);
332
if(conflict_detection()){
334
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
340
111
fprintf(stderr, "Storing current terminal attributes\n");
343
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
345
error_plus(0, errno, "tcgetattr");
349
return EX_UNAVAILABLE;
114
if (tcgetattr(STDIN_FILENO, &t_old) != 0){
355
118
sigemptyset(&new_action.sa_mask);
356
ret = sigaddset(&new_action.sa_mask, SIGINT);
358
error_plus(0, errno, "sigaddset");
361
ret = sigaddset(&new_action.sa_mask, SIGHUP);
363
error_plus(0, errno, "sigaddset");
366
ret = sigaddset(&new_action.sa_mask, SIGTERM);
368
error_plus(0, errno, "sigaddset");
371
/* Need to check if the handler is SIG_IGN before handling:
372
| [[info:libc:Initial Signal Actions]] |
373
| [[info:libc:Basic Signal Handling]] |
375
ret = sigaction(SIGINT, NULL, &old_action);
377
error_plus(0, errno, "sigaction");
380
if(old_action.sa_handler != SIG_IGN){
381
ret = sigaction(SIGINT, &new_action, NULL);
383
error_plus(0, errno, "sigaction");
387
ret = sigaction(SIGHUP, NULL, &old_action);
389
error_plus(0, errno, "sigaction");
392
if(old_action.sa_handler != SIG_IGN){
393
ret = sigaction(SIGHUP, &new_action, NULL);
395
error_plus(0, errno, "sigaction");
399
ret = sigaction(SIGTERM, NULL, &old_action);
401
error_plus(0, errno, "sigaction");
404
if(old_action.sa_handler != SIG_IGN){
405
ret = sigaction(SIGTERM, &new_action, NULL);
407
error_plus(0, errno, "sigaction");
119
sigaddset(&new_action.sa_mask, SIGINT);
120
sigaddset(&new_action.sa_mask, SIGHUP);
121
sigaddset(&new_action.sa_mask, SIGTERM);
122
sigaction(SIGINT, NULL, &old_action);
123
if (old_action.sa_handler != SIG_IGN)
124
sigaction(SIGINT, &new_action, NULL);
125
sigaction(SIGHUP, NULL, &old_action);
126
if (old_action.sa_handler != SIG_IGN)
127
sigaction(SIGHUP, &new_action, NULL);
128
sigaction(SIGTERM, NULL, &old_action);
129
if (old_action.sa_handler != SIG_IGN)
130
sigaction(SIGTERM, &new_action, NULL);
414
134
fprintf(stderr, "Removing echo flag from terminal attributes\n");
418
t_new.c_lflag &= ~(tcflag_t)ECHO;
419
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
421
error_plus(0, errno, "tcsetattr-echo");
425
return EX_UNAVAILABLE;
138
t_new.c_lflag &= ~ECHO;
139
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
140
perror("tcsetattr-echo");
433
145
fprintf(stderr, "Waiting for input from stdin \n");
438
fprintf(stderr, "Interrupted by signal, exiting.\n");
440
149
status = EXIT_FAILURE;
445
fprintf(stderr, "%s ", prefix);
448
fprintf(stderr, "%s: ", prompt);
154
fprintf(stderr, "%s Password: ", prefix);
450
const char *cryptsource = getenv("CRYPTTAB_SOURCE");
451
const char *crypttarget = getenv("CRYPTTAB_NAME");
452
/* Before cryptsetup 1.1.0~rc2 */
453
if(cryptsource == NULL){
454
cryptsource = getenv("cryptsource");
456
if(crypttarget == NULL){
457
crypttarget = getenv("crypttarget");
459
const char *const prompt1 = "Unlocking the disk";
460
const char *const prompt2 = "Enter passphrase";
461
if(cryptsource == NULL){
462
if(crypttarget == NULL){
463
fprintf(stderr, "%s to unlock the disk: ", prompt2);
465
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
469
if(crypttarget == NULL){
470
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
473
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
474
crypttarget, prompt2);
478
sret = getline(&buffer, &n, stdin);
156
fprintf(stderr, "Password: ");
158
ret = getline(&buffer, &n, stdin);
160
fprintf(stdout, "%s", buffer);
480
161
status = EXIT_SUCCESS;
481
/* Make n = data size instead of allocated buffer size */
483
/* Strip final newline */
484
if(n > 0 and buffer[n-1] == '\n'){
485
buffer[n-1] = '\0'; /* not strictly necessary */
490
sret = write(STDOUT_FILENO, buffer + written, n - written);
493
error_plus(0, errno, "write");
505
status = EXIT_FAILURE;
510
written += (size_t)sret;
512
sret = close(STDOUT_FILENO);
515
error_plus(0, errno, "close");
532
error_plus(0, errno, "getline");
535
status = EX_UNAVAILABLE;
165
if (errno != EINTR and not feof(stdin)){
167
status = EXIT_FAILURE;
549
/* if(sret == 0), then the only sensible thing to do is to retry
550
to read from stdin */
171
/* if(ret == 0), then the only sensible thing to do is to retry to
551
173
fputc('\n', stderr);
552
if(debug and not quit_now){
553
/* If quit_now is nonzero, we were interrupted by a signal, and
554
will print that later, so no need to show this too. */
555
fprintf(stderr, "getline() returned 0, retrying.\n");
562
177
fprintf(stderr, "Restoring terminal attributes\n");
564
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
565
error_plus(0, errno, "tcsetattr+echo");
569
sigemptyset(&old_action.sa_mask);
570
old_action.sa_handler = SIG_DFL;
571
ret = sigaction(signal_received, &old_action, NULL);
573
error_plus(0, errno, "sigaction");
575
raise(signal_received);
579
fprintf(stderr, "%s is exiting with status %d\n", argv[0],
582
if(status == EXIT_SUCCESS or status == EX_OK){
179
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
180
perror("tcsetattr+echo");
184
fprintf(stderr, "%s is exiting\n", argv[0]);