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 © 2008-2019, 2021-2022 Teddy Hogeborn
6
* Copyright © 2008-2019, 2021-2022 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() */
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,
26
#define _GNU_SOURCE /* vasprintf(),
27
program_invocation_short_name,
28
asprintf(), getline() */
29
#include <sys/types.h> /* sig_atomic_t, pid_t */
30
#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,
37
#include <stddef.h> /* NULL, size_t, ssize_t */
38
#include <sys/types.h> /* ssize_t */
39
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
40
getopt_long, getenv() */
41
#include <stdio.h> /* fprintf(), stderr, getline(),
42
stdin, feof(), perror(), fputc(),
44
#include <errno.h> /* errno, EBADF, ENOTTY, EINVAL,
45
EFAULT, EFBIG, EIO, ENOSPC, EINTR
47
#include <iso646.h> /* or, not */
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* strlen, rindex, strncmp, strcmp */
50
#include <argp.h> /* struct argp_option, struct
51
argp_state, struct argp,
52
argp_parse(), error_t,
53
ARGP_KEY_ARG, ARGP_KEY_END,
55
#include <sysexits.h> /* EX_SOFTWARE, EX_OSERR,
56
EX_UNAVAILABLE, EX_IOERR, EX_OK */
70
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
71
EX_IOERR, EX_OSFILE, EX_OK */
58
73
volatile sig_atomic_t quit_now = 0;
59
74
int signal_received;
60
75
bool debug = false;
61
76
const char *argp_program_version = "password-prompt " VERSION;
62
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
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);
64
105
static void termination_handler(int signum){
69
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");
72
240
int main(int argc, char **argv){
75
244
struct termios t_new, t_old;
76
245
char *buffer = NULL;
77
246
char *prefix = NULL;
78
248
int status = EXIT_SUCCESS;
79
249
struct sigaction old_action,
80
250
new_action = { .sa_handler = termination_handler,
84
254
{ .name = "prefix", .key = 'p',
85
255
.arg = "PREFIX", .flags = 0,
86
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 },
87
260
{ .name = "debug", .key = 128,
88
261
.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)))
92
275
error_t parse_opt (int key, char *arg, struct argp_state *state){
278
case 'p': /* --prefix */
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);
106
304
return ARGP_ERR_UNKNOWN;
111
309
struct argp argp = { .options = options, .parser = parse_opt,
113
311
.doc = "Mandos password-prompt -- Read and"
114
312
" output a password" };
115
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
116
if(ret == ARGP_ERR_UNKNOWN){
117
fprintf(stderr, "Unknown error while parsing arguments\n");
313
ret = argp_parse(&argp, argc, argv,
314
ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
321
error_plus(0, errno, "argp_parse");
123
329
fprintf(stderr, "Starting %s\n", argv[0]);
332
if(conflict_detection()){
334
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
126
340
fprintf(stderr, "Storing current terminal attributes\n");
129
343
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
345
error_plus(0, errno, "tcgetattr");
231
445
fprintf(stderr, "%s ", prefix);
234
const char *cryptsource = getenv("cryptsource");
235
const char *crypttarget = getenv("crypttarget");
236
const char *const prompt
237
= "Enter passphrase to unlock the disk";
448
fprintf(stderr, "%s: ", prompt);
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";
238
461
if(cryptsource == NULL){
239
462
if(crypttarget == NULL){
240
fprintf(stderr, "%s: ", prompt);
463
fprintf(stderr, "%s to unlock the disk: ", prompt2);
242
fprintf(stderr, "%s (%s): ", prompt, crypttarget);
465
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
245
469
if(crypttarget == NULL){
246
fprintf(stderr, "%s %s: ", prompt, cryptsource);
470
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
248
fprintf(stderr, "%s %s (%s): ", prompt, cryptsource,
473
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
474
crypttarget, prompt2);
253
ret = getline(&buffer, &n, stdin);
478
sret = getline(&buffer, &n, stdin);
255
480
status = EXIT_SUCCESS;
256
481
/* Make n = data size instead of allocated buffer size */
258
483
/* Strip final newline */
259
484
if(n > 0 and buffer[n-1] == '\n'){
260
485
buffer[n-1] = '\0'; /* not strictly necessary */