19
18
* along with this program. If not, see
20
19
* <http://www.gnu.org/licenses/>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
21
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
22
* <https://www.fukt.bsnet.se/~teddy/>.
25
#define _GNU_SOURCE /* getline(), asprintf() */
25
#define _GNU_SOURCE /* getline() */
27
#include <termios.h> /* struct termios, tcsetattr(),
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,
35
SIGQUIT, SIGHUP, SIGTERM */
37
36
#include <stddef.h> /* NULL, size_t, ssize_t */
38
#include <sys/types.h> /* ssize_t, struct dirent, pid_t,
37
#include <sys/types.h> /* ssize_t */
40
38
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
42
#include <dirent.h> /* scandir(), alphasort() */
43
40
#include <stdio.h> /* fprintf(), stderr, getline(),
44
stdin, feof(), fputc(), vfprintf(),
46
#include <errno.h> /* errno, EBADF, ENOTTY, EINVAL,
47
EFAULT, EFBIG, EIO, ENOSPC, EINTR
49
#include <error.h> /* error() */
41
stdin, feof(), perror(), fputc(),
42
stdout, getopt_long */
43
#include <errno.h> /* errno, EINVAL */
50
44
#include <iso646.h> /* or, not */
51
45
#include <stdbool.h> /* bool, false, true */
52
#include <inttypes.h> /* strtoumax() */
53
#include <sys/stat.h> /* struct stat, lstat(), open() */
54
#include <string.h> /* strlen, rindex, memcmp, strerror()
46
#include <string.h> /* strlen, rindex, strncmp, strcmp */
56
47
#include <argp.h> /* struct argp_option, struct
57
48
argp_state, struct argp,
58
49
argp_parse(), error_t,
59
50
ARGP_KEY_ARG, ARGP_KEY_END,
60
51
ARGP_ERR_UNKNOWN */
61
#include <sysexits.h> /* EX_SOFTWARE, EX_OSERR,
62
EX_UNAVAILABLE, EX_IOERR, EX_OK */
63
#include <fcntl.h> /* open() */
64
#include <stdarg.h> /* va_list, va_start(), ... */
66
volatile sig_atomic_t quit_now = 0;
53
volatile bool quit_now = false;
68
54
bool debug = false;
69
const char *argp_program_version = "password-prompt " VERSION;
55
const char *argp_program_version = "passprompt 1.0";
70
56
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
72
/* Needed for conflict resolution */
73
const char plymouth_name[] = "plymouthd";
75
/* Function to use when printing errors */
76
void error_plus(int status, int errnum, const char *formatstring,
82
va_start(ap, formatstring);
83
ret = vasprintf(&text, formatstring, ap);
85
fprintf(stderr, "Mandos plugin %s: ",
86
program_invocation_short_name);
87
vfprintf(stderr, formatstring, ap);
88
fprintf(stderr, ": ");
89
fprintf(stderr, "%s\n", strerror(errnum));
90
error(status, errno, "vasprintf while printing error");
93
fprintf(stderr, "Mandos plugin ");
94
error(status, errnum, "%s", text);
98
static void termination_handler(int signum){
103
signal_received = signum;
106
bool conflict_detection(void){
108
/* plymouth conflicts with password-prompt since both want to read
109
from the terminal. Password-prompt will exit if it detects
110
plymouth since plymouth performs the same functionality.
112
int is_plymouth(const struct dirent *proc_entry){
119
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
121
if(errno != 0 or *tmp != '\0'
122
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
127
char *cmdline_filename;
128
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
131
error(0, errno, "asprintf");
135
/* Open /proc/<pid>/cmdline */
136
cl_fd = open(cmdline_filename, O_RDONLY);
137
free(cmdline_filename);
140
error(0, errno, "open");
145
char *cmdline = NULL;
147
size_t cmdline_len = 0;
148
size_t cmdline_allocated = 0;
150
const size_t blocksize = 1024;
153
/* Allocate more space? */
154
if(cmdline_len + blocksize + 1 > cmdline_allocated){
155
tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
157
error(0, errno, "realloc");
163
cmdline_allocated += blocksize;
167
sret = read(cl_fd, cmdline + cmdline_len,
168
cmdline_allocated - cmdline_len);
170
error(0, errno, "read");
175
cmdline_len += (size_t)sret;
179
error(0, errno, "close");
183
cmdline[cmdline_len] = '\0'; /* Make sure it is terminated */
185
/* we now have cmdline */
188
char *cmdline_base = strrchr(cmdline, '/');
189
if(cmdline_base != NULL){
190
cmdline_base += 1; /* skip the slash */
192
cmdline_base = cmdline;
195
if(strcmp(cmdline_base, plymouth_name) != 0){
197
fprintf(stderr, "\"%s\" is not \"%s\"\n", cmdline_base,
204
fprintf(stderr, "\"%s\" equals \"%s\"\n", cmdline_base,
211
struct dirent **direntries = NULL;
213
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
215
error(1, errno, "scandir");
58
static void termination_handler(__attribute__((unused))int signum){
222
62
int main(int argc, char **argv){
226
65
struct termios t_new, t_old;
227
66
char *buffer = NULL;
234
73
struct argp_option options[] = {
235
74
{ .name = "prefix", .key = 'p',
236
75
.arg = "PREFIX", .flags = 0,
237
.doc = "Prefix shown before the prompt", .group = 2 },
76
.doc = "Prefix used before the passprompt", .group = 2 },
238
77
{ .name = "debug", .key = 128,
239
78
.doc = "Debug mode", .group = 3 },
241
* These reproduce what we would get without ARGP_NO_HELP
243
{ .name = "help", .key = '?',
244
.doc = "Give this help list", .group = -1 },
245
{ .name = "usage", .key = -3,
246
.doc = "Give a short usage message", .group = -1 },
247
{ .name = "version", .key = 'V',
248
.doc = "Print program version", .group = -1 },
252
error_t parse_opt (int key, char *arg, struct argp_state *state){
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. */
262
* These reproduce what we would get without ARGP_NO_HELP
264
case '?': /* --help */
265
argp_state_help(state, state->out_stream,
266
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
267
& ~(unsigned int)ARGP_HELP_EXIT_OK);
268
case -3: /* --usage */
269
argp_state_help(state, state->out_stream,
270
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
271
case 'V': /* --version */
272
fprintf(state->out_stream, "%s\n", argp_program_version);
273
exit(argp_err_exit_status);
276
98
return ARGP_ERR_UNKNOWN;
281
103
struct argp argp = { .options = options, .parser = parse_opt,
283
.doc = "Mandos password-prompt -- Read and"
284
" output a password" };
285
ret = argp_parse(&argp, argc, argv,
286
ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
293
error(0, errno, "argp_parse");
105
.doc = "Mandos Passprompt -- Provides a passprompt" };
106
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
107
if (ret == ARGP_ERR_UNKNOWN){
108
fprintf(stderr, "Unkown error while parsing arguments\n");
301
114
fprintf(stderr, "Starting %s\n", argv[0]);
304
if (conflict_detection()){
306
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
312
117
fprintf(stderr, "Storing current terminal attributes\n");
315
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
317
error(0, errno, "tcgetattr");
321
return EX_UNAVAILABLE;
120
if (tcgetattr(STDIN_FILENO, &t_old) != 0){
327
124
sigemptyset(&new_action.sa_mask);
328
ret = sigaddset(&new_action.sa_mask, SIGINT);
330
error(0, errno, "sigaddset");
333
ret = sigaddset(&new_action.sa_mask, SIGHUP);
335
error(0, errno, "sigaddset");
338
ret = sigaddset(&new_action.sa_mask, SIGTERM);
340
error(0, errno, "sigaddset");
343
/* Need to check if the handler is SIG_IGN before handling:
344
| [[info:libc:Initial Signal Actions]] |
345
| [[info:libc:Basic Signal Handling]] |
125
sigaddset(&new_action.sa_mask, SIGINT);
126
sigaddset(&new_action.sa_mask, SIGHUP);
127
sigaddset(&new_action.sa_mask, SIGTERM);
347
128
ret = sigaction(SIGINT, NULL, &old_action);
349
error(0, errno, "sigaction");
352
if(old_action.sa_handler != SIG_IGN){
133
if (old_action.sa_handler != SIG_IGN){
353
134
ret = sigaction(SIGINT, &new_action, NULL);
355
error(0, errno, "sigaction");
359
140
ret = sigaction(SIGHUP, NULL, &old_action);
361
error(0, errno, "sigaction");
364
if(old_action.sa_handler != SIG_IGN){
145
if (old_action.sa_handler != SIG_IGN){
365
146
ret = sigaction(SIGHUP, &new_action, NULL);
367
error(0, errno, "sigaction");
371
152
ret = sigaction(SIGTERM, NULL, &old_action);
373
error(0, errno, "sigaction");
376
if(old_action.sa_handler != SIG_IGN){
157
if (old_action.sa_handler != SIG_IGN){
377
158
ret = sigaction(SIGTERM, &new_action, NULL);
379
error(0, errno, "sigaction");
386
167
fprintf(stderr, "Removing echo flag from terminal attributes\n");
390
t_new.c_lflag &= ~(tcflag_t)ECHO;
391
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
393
error(0, errno, "tcsetattr-echo");
397
return EX_UNAVAILABLE;
171
t_new.c_lflag &= ~ECHO;
172
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
173
perror("tcsetattr-echo");
405
178
fprintf(stderr, "Waiting for input from stdin \n");
410
fprintf(stderr, "Interrupted by signal, exiting.\n");
412
182
status = EXIT_FAILURE;
417
fprintf(stderr, "%s ", prefix);
420
const char *cryptsource = getenv("CRYPTTAB_SOURCE");
421
const char *crypttarget = getenv("CRYPTTAB_NAME");
422
/* Before cryptsetup 1.1.0~rc2 */
423
if(cryptsource == NULL){
424
cryptsource = getenv("cryptsource");
426
if(crypttarget == NULL){
427
crypttarget = getenv("crypttarget");
429
const char *const prompt1 = "Unlocking the disk";
430
const char *const prompt2 = "Enter passphrase";
431
if(cryptsource == NULL){
432
if(crypttarget == NULL){
433
fprintf(stderr, "%s to unlock the disk: ", prompt2);
435
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
439
if(crypttarget == NULL){
440
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
443
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
444
crypttarget, prompt2);
448
sret = getline(&buffer, &n, stdin);
187
fprintf(stderr, "%s Password: ", prefix);
189
fprintf(stderr, "Password: ");
191
ret = getline(&buffer, &n, stdin);
193
fprintf(stdout, "%s", buffer);
450
194
status = EXIT_SUCCESS;
451
/* Make n = data size instead of allocated buffer size */
453
/* Strip final newline */
454
if(n > 0 and buffer[n-1] == '\n'){
455
buffer[n-1] = '\0'; /* not strictly necessary */
460
sret = write(STDOUT_FILENO, buffer + written, n - written);
463
error(0, errno, "write");
475
status = EXIT_FAILURE;
480
written += (size_t)sret;
482
sret = close(STDOUT_FILENO);
485
error(0, errno, "close");
500
if(errno != EINTR and not feof(stdin)){
501
error(0, errno, "getline");
504
status = EX_UNAVAILABLE;
198
if (errno != EINTR and not feof(stdin)){
200
status = EXIT_FAILURE;
514
/* if(sret == 0), then the only sensible thing to do is to retry
515
to read from stdin */
204
/* if(ret == 0), then the only sensible thing to do is to retry to
516
206
fputc('\n', stderr);
517
if(debug and not quit_now){
518
/* If quit_now is nonzero, we were interrupted by a signal, and
519
will print that later, so no need to show this too. */
520
fprintf(stderr, "getline() returned 0, retrying.\n");
527
210
fprintf(stderr, "Restoring terminal attributes\n");
529
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
530
error(0, errno, "tcsetattr+echo");
534
sigemptyset(&old_action.sa_mask);
535
old_action.sa_handler = SIG_DFL;
536
ret = sigaction(signal_received, &old_action, NULL);
538
error(0, errno, "sigaction");
540
raise(signal_received);
544
fprintf(stderr, "%s is exiting with status %d\n", argv[0],
547
if(status == EXIT_SUCCESS or status == EX_OK){
212
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
213
perror("tcsetattr+echo");
217
fprintf(stderr, "%s is exiting\n", argv[0]);