18
19
* along with this program. If not, see
19
20
* <http://www.gnu.org/licenses/>.
21
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
22
* <https://www.fukt.bsnet.se/~teddy/>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
25
#define _GNU_SOURCE /* getline() */
25
#define _GNU_SOURCE /* getline(), asprintf() */
27
27
#include <termios.h> /* struct termios, tcsetattr(),
28
28
TCSAFLUSH, tcgetattr(), ECHO */
29
29
#include <unistd.h> /* struct termios, tcsetattr(),
30
30
STDIN_FILENO, TCSAFLUSH,
31
tcgetattr(), ECHO, readlink() */
32
32
#include <signal.h> /* sig_atomic_t, raise(), struct
33
33
sigaction, sigemptyset(),
34
34
sigaction(), sigaddset(), SIGINT,
35
SIGQUIT, SIGHUP, SIGTERM */
36
#include <stddef.h> /* NULL, size_t */
37
#include <sys/types.h> /* ssize_t */
35
SIGQUIT, SIGHUP, SIGTERM,
37
#include <stddef.h> /* NULL, size_t, ssize_t */
38
#include <sys/types.h> /* ssize_t, struct dirent, pid_t,
38
40
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
42
#include <dirent.h> /* scandir(), alphasort() */
40
43
#include <stdio.h> /* fprintf(), stderr, getline(),
41
stdin, feof(), perror(), fputc(),
42
stdout, getopt_long */
43
#include <errno.h> /* errno, EINVAL */
44
stdin, feof(), fputc()
46
#include <errno.h> /* errno, EBADF, ENOTTY, EINVAL,
47
EFAULT, EFBIG, EIO, ENOSPC, EINTR
49
#include <error.h> /* error() */
44
50
#include <iso646.h> /* or, not */
45
51
#include <stdbool.h> /* bool, false, true */
46
#include <string.h> /* strlen, rindex, strncmp, strcmp */
47
#include <argp.h> /* struct argp_option,
48
struct argp_state, struct argp,
52
#include <inttypes.h> /* strtoumax() */
53
#include <sys/stat.h> /* struct stat, lstat(), open() */
54
#include <string.h> /* strlen, rindex, memcmp */
55
#include <argp.h> /* struct argp_option, struct
56
argp_state, struct argp,
57
argp_parse(), error_t,
58
ARGP_KEY_ARG, ARGP_KEY_END,
60
#include <sysexits.h> /* EX_SOFTWARE, EX_OSERR,
61
EX_UNAVAILABLE, EX_IOERR, EX_OK */
62
#include <fcntl.h> /* open() */
51
volatile bool quit_now = false;
64
volatile sig_atomic_t quit_now = 0;
52
66
bool debug = false;
53
const char *argp_program_version = "passprompt 0.9";
67
const char *argp_program_version = "password-prompt " VERSION;
54
68
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
56
static void termination_handler(__attribute__((unused))int signum){
70
/* Needed for conflict resolution */
71
const char plymouth_name[] = "plymouthd";
72
const char plymouth_alt_name[] = "plymouthd";
75
static void termination_handler(int signum){
80
signal_received = signum;
83
bool conflict_detection(void){
85
/* plymouth conflicts with password-prompt since both want to read
86
from the terminal. Password-prompt will exit if it detects
87
plymouth since plymouth performs the same functionality.
89
int is_plymouth(const struct dirent *proc_entry){
96
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
98
if(errno != 0 or *tmp != '\0'
99
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
104
char *cmdline_filename;
105
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline", proc_entry->d_name);
107
error(0, errno, "asprintf");
111
/* Open /proc/<pid>/cmdline */
112
cl_fd = open(cmdline_filename, O_RDONLY);
113
free(cmdline_filename);
115
error(0, errno, "open");
119
char *cmdline = NULL;
121
size_t cmdline_len = 0;
122
size_t cmdline_allocated = 0;
124
const size_t blocksize = 1024;
127
/* Allocate more space? */
128
if(cmdline_len + blocksize + 1 > cmdline_allocated){
129
tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
131
error(0, errno, "realloc");
137
cmdline_allocated += blocksize;
141
sret = read(cl_fd, cmdline + cmdline_len,
142
cmdline_allocated - cmdline_len);
144
error(0, errno, "read");
149
cmdline_len += (size_t)sret;
153
error(0, errno, "close");
157
cmdline[cmdline_len] = '\0'; /* Make sure it is terminated */
159
/* we now have cmdline */
162
char *cmdline_base = strrchr(cmdline, '/');
163
if(cmdline_base != NULL){
164
cmdline_base += 1; /* skip the slash */
166
cmdline_base = cmdline;
169
if((strcmp(cmdline_base, plymouth_name) != 0)
170
and (strcmp(cmdline_base, plymouth_alt_name) != 0)){
178
struct dirent **direntries;
180
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
182
error(1, errno, "scandir");
60
188
int main(int argc, char **argv){
63
192
struct termios t_new, t_old;
64
193
char *buffer = NULL;
71
200
struct argp_option options[] = {
72
201
{ .name = "prefix", .key = 'p',
73
202
.arg = "PREFIX", .flags = 0,
74
.doc = "Prefix used before the passprompt", .group = 2 },
203
.doc = "Prefix shown before the prompt", .group = 2 },
75
204
{ .name = "debug", .key = 128,
76
205
.doc = "Debug mode", .group = 3 },
207
* These reproduce what we would get without ARGP_NO_HELP
209
{ .name = "help", .key = '?',
210
.doc = "Give this help list", .group = -1 },
211
{ .name = "usage", .key = -3,
212
.doc = "Give a short usage message", .group = -1 },
213
{ .name = "version", .key = 'V',
214
.doc = "Print program version", .group = -1 },
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. */
218
error_t parse_opt (int key, char *arg, struct argp_state *state){
228
* These reproduce what we would get without ARGP_NO_HELP
230
case '?': /* --help */
231
argp_state_help(state, state->out_stream,
232
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
233
& ~(unsigned int)ARGP_HELP_EXIT_OK);
234
case -3: /* --usage */
235
argp_state_help(state, state->out_stream,
236
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
237
case 'V': /* --version */
238
fprintf(state->out_stream, "%s\n", argp_program_version);
239
exit(argp_err_exit_status);
96
242
return ARGP_ERR_UNKNOWN;
101
247
struct argp argp = { .options = options, .parser = parse_opt,
103
.doc = "Mandos Passprompt -- Provides a passprompt" };
104
argp_parse (&argp, argc, argv, 0, 0, NULL);
249
.doc = "Mandos password-prompt -- Read and"
250
" output a password" };
251
ret = argp_parse(&argp, argc, argv,
252
ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
259
error(0, errno, "argp_parse");
108
267
fprintf(stderr, "Starting %s\n", argv[0]);
270
if (conflict_detection()){
272
fprintf(stderr, "Stopping %s because of conflict", argv[0]);
111
278
fprintf(stderr, "Storing current terminal attributes\n");
114
if (tcgetattr(STDIN_FILENO, &t_old) != 0){
281
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
283
error(0, errno, "tcgetattr");
287
return EX_UNAVAILABLE;
118
293
sigemptyset(&new_action.sa_mask);
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);
294
ret = sigaddset(&new_action.sa_mask, SIGINT);
296
error(0, errno, "sigaddset");
299
ret = sigaddset(&new_action.sa_mask, SIGHUP);
301
error(0, errno, "sigaddset");
304
ret = sigaddset(&new_action.sa_mask, SIGTERM);
306
error(0, errno, "sigaddset");
309
/* Need to check if the handler is SIG_IGN before handling:
310
| [[info:libc:Initial Signal Actions]] |
311
| [[info:libc:Basic Signal Handling]] |
313
ret = sigaction(SIGINT, NULL, &old_action);
315
error(0, errno, "sigaction");
318
if(old_action.sa_handler != SIG_IGN){
319
ret = sigaction(SIGINT, &new_action, NULL);
321
error(0, errno, "sigaction");
325
ret = sigaction(SIGHUP, NULL, &old_action);
327
error(0, errno, "sigaction");
330
if(old_action.sa_handler != SIG_IGN){
331
ret = sigaction(SIGHUP, &new_action, NULL);
333
error(0, errno, "sigaction");
337
ret = sigaction(SIGTERM, NULL, &old_action);
339
error(0, errno, "sigaction");
342
if(old_action.sa_handler != SIG_IGN){
343
ret = sigaction(SIGTERM, &new_action, NULL);
345
error(0, errno, "sigaction");
134
352
fprintf(stderr, "Removing echo flag from terminal attributes\n");
138
t_new.c_lflag &= ~ECHO;
139
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
140
perror("tcsetattr-echo");
356
t_new.c_lflag &= ~(tcflag_t)ECHO;
357
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
359
error(0, errno, "tcsetattr-echo");
363
return EX_UNAVAILABLE;
145
371
fprintf(stderr, "Waiting for input from stdin \n");
376
fprintf(stderr, "Interrupted by signal, exiting.\n");
149
378
status = EXIT_FAILURE;
154
fprintf(stderr, "%s Password: ", prefix);
156
fprintf(stderr, "Password: ");
158
ret = getline(&buffer, &n, stdin);
160
fprintf(stdout, "%s", buffer);
383
fprintf(stderr, "%s ", prefix);
386
const char *cryptsource = getenv("CRYPTTAB_SOURCE");
387
const char *crypttarget = getenv("CRYPTTAB_NAME");
388
/* Before cryptsetup 1.1.0~rc2 */
389
if(cryptsource == NULL){
390
cryptsource = getenv("cryptsource");
392
if(crypttarget == NULL){
393
crypttarget = getenv("crypttarget");
395
const char *const prompt1 = "Unlocking the disk";
396
const char *const prompt2 = "Enter passphrase";
397
if(cryptsource == NULL){
398
if(crypttarget == NULL){
399
fprintf(stderr, "%s to unlock the disk: ", prompt2);
401
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
405
if(crypttarget == NULL){
406
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
409
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
410
crypttarget, prompt2);
414
sret = getline(&buffer, &n, stdin);
161
416
status = EXIT_SUCCESS;
417
/* Make n = data size instead of allocated buffer size */
419
/* Strip final newline */
420
if(n > 0 and buffer[n-1] == '\n'){
421
buffer[n-1] = '\0'; /* not strictly necessary */
426
sret = write(STDOUT_FILENO, buffer + written, n - written);
429
error(0, errno, "write");
441
status = EXIT_FAILURE;
446
written += (size_t)sret;
448
sret = close(STDOUT_FILENO);
451
error(0, errno, "close");
165
if (errno != EINTR and not feof(stdin)){
167
status = EXIT_FAILURE;
466
if(errno != EINTR and not feof(stdin)){
467
error(0, errno, "getline");
470
status = EX_UNAVAILABLE;
171
/* if(ret == 0), then the only sensible thing to do is to retry to
480
/* if(sret == 0), then the only sensible thing to do is to retry to
172
481
read from stdin */
173
482
fputc('\n', stderr);
483
if(debug and not quit_now){
484
/* If quit_now is nonzero, we were interrupted by a signal, and
485
will print that later, so no need to show this too. */
486
fprintf(stderr, "getline() returned 0, retrying.\n");
177
493
fprintf(stderr, "Restoring terminal attributes\n");
179
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
180
perror("tcsetattr+echo");
184
fprintf(stderr, "%s is exiting\n", argv[0]);
495
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
496
error(0, errno, "tcsetattr+echo");
500
sigemptyset(&old_action.sa_mask);
501
old_action.sa_handler = SIG_DFL;
502
ret = sigaction(signal_received, &old_action, NULL);
504
error(0, errno, "sigaction");
506
raise(signal_received);
510
fprintf(stderr, "%s is exiting with status %d\n", argv[0],
513
if(status == EXIT_SUCCESS or status == EX_OK){