19
18
* along with this program. If not, see
20
19
* <http://www.gnu.org/licenses/>.
22
* 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/>.
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;
70
const char *argp_program_bug_address = "<mandos@recompile.se>";
72
/* Needed for conflict resolution */
73
const char plymouth_name[] = "plymouthd";
75
/* Function to use when printing errors */
76
__attribute__((format (gnu_printf, 3, 4)))
77
void error_plus(int status, int errnum, const char *formatstring,
83
va_start(ap, formatstring);
84
ret = vasprintf(&text, formatstring, ap);
86
fprintf(stderr, "Mandos plugin %s: ",
87
program_invocation_short_name);
88
vfprintf(stderr, formatstring, ap);
89
fprintf(stderr, ": ");
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
int is_plymouth(const struct dirent *proc_entry){
120
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
122
if(errno != 0 or *tmp != '\0'
123
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
128
char *cmdline_filename;
129
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
132
error(0, errno, "asprintf");
136
/* Open /proc/<pid>/cmdline */
137
cl_fd = open(cmdline_filename, O_RDONLY);
138
free(cmdline_filename);
141
error(0, errno, "open");
146
char *cmdline = NULL;
148
size_t cmdline_len = 0;
149
size_t cmdline_allocated = 0;
151
const size_t blocksize = 1024;
154
/* Allocate more space? */
155
if(cmdline_len + blocksize + 1 > cmdline_allocated){
156
tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
158
error(0, errno, "realloc");
164
cmdline_allocated += blocksize;
168
sret = read(cl_fd, cmdline + cmdline_len,
169
cmdline_allocated - cmdline_len);
171
error(0, errno, "read");
176
cmdline_len += (size_t)sret;
180
error(0, errno, "close");
184
cmdline[cmdline_len] = '\0'; /* Make sure it is terminated */
186
/* we now have cmdline */
189
char *cmdline_base = strrchr(cmdline, '/');
190
if(cmdline_base != NULL){
191
cmdline_base += 1; /* skip the slash */
193
cmdline_base = cmdline;
196
if(strcmp(cmdline_base, plymouth_name) != 0){
198
fprintf(stderr, "\"%s\" is not \"%s\"\n", cmdline_base,
205
fprintf(stderr, "\"%s\" equals \"%s\"\n", cmdline_base,
212
struct dirent **direntries = NULL;
214
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
216
error(1, errno, "scandir");
55
const char *argp_program_version = "password-prompt 1.0";
56
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
58
static void termination_handler(__attribute__((unused))int signum){
223
62
int main(int argc, char **argv){
227
65
struct termios t_new, t_old;
228
66
char *buffer = NULL;
235
73
struct argp_option options[] = {
236
74
{ .name = "prefix", .key = 'p',
237
75
.arg = "PREFIX", .flags = 0,
238
.doc = "Prefix shown before the prompt", .group = 2 },
76
.doc = "Prefix used before the passprompt", .group = 2 },
239
77
{ .name = "debug", .key = 128,
240
78
.doc = "Debug mode", .group = 3 },
242
* These reproduce what we would get without ARGP_NO_HELP
244
{ .name = "help", .key = '?',
245
.doc = "Give this help list", .group = -1 },
246
{ .name = "usage", .key = -3,
247
.doc = "Give a short usage message", .group = -1 },
248
{ .name = "version", .key = 'V',
249
.doc = "Print program version", .group = -1 },
253
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. */
263
* These reproduce what we would get without ARGP_NO_HELP
265
case '?': /* --help */
266
argp_state_help(state, state->out_stream,
267
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
268
& ~(unsigned int)ARGP_HELP_EXIT_OK);
269
case -3: /* --usage */
270
argp_state_help(state, state->out_stream,
271
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
272
case 'V': /* --version */
273
fprintf(state->out_stream, "%s\n", argp_program_version);
274
exit(argp_err_exit_status);
277
98
return ARGP_ERR_UNKNOWN;
282
103
struct argp argp = { .options = options, .parser = parse_opt,
284
.doc = "Mandos password-prompt -- Read and"
285
" output a password" };
286
ret = argp_parse(&argp, argc, argv,
287
ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
294
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, "Unknown error while parsing arguments\n");
302
114
fprintf(stderr, "Starting %s\n", argv[0]);
305
if (conflict_detection()){
307
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
313
117
fprintf(stderr, "Storing current terminal attributes\n");
316
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
318
error(0, errno, "tcgetattr");
322
return EX_UNAVAILABLE;
120
if (tcgetattr(STDIN_FILENO, &t_old) != 0){
328
124
sigemptyset(&new_action.sa_mask);
329
ret = sigaddset(&new_action.sa_mask, SIGINT);
331
error(0, errno, "sigaddset");
334
ret = sigaddset(&new_action.sa_mask, SIGHUP);
336
error(0, errno, "sigaddset");
339
ret = sigaddset(&new_action.sa_mask, SIGTERM);
341
error(0, errno, "sigaddset");
344
/* Need to check if the handler is SIG_IGN before handling:
345
| [[info:libc:Initial Signal Actions]] |
346
| [[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);
348
128
ret = sigaction(SIGINT, NULL, &old_action);
350
error(0, errno, "sigaction");
353
if(old_action.sa_handler != SIG_IGN){
133
if (old_action.sa_handler != SIG_IGN){
354
134
ret = sigaction(SIGINT, &new_action, NULL);
356
error(0, errno, "sigaction");
360
140
ret = sigaction(SIGHUP, NULL, &old_action);
362
error(0, errno, "sigaction");
365
if(old_action.sa_handler != SIG_IGN){
145
if (old_action.sa_handler != SIG_IGN){
366
146
ret = sigaction(SIGHUP, &new_action, NULL);
368
error(0, errno, "sigaction");
372
152
ret = sigaction(SIGTERM, NULL, &old_action);
374
error(0, errno, "sigaction");
377
if(old_action.sa_handler != SIG_IGN){
157
if (old_action.sa_handler != SIG_IGN){
378
158
ret = sigaction(SIGTERM, &new_action, NULL);
380
error(0, errno, "sigaction");
387
167
fprintf(stderr, "Removing echo flag from terminal attributes\n");
391
t_new.c_lflag &= ~(tcflag_t)ECHO;
392
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
394
error(0, errno, "tcsetattr-echo");
398
return EX_UNAVAILABLE;
171
t_new.c_lflag &= ~ECHO;
172
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
173
perror("tcsetattr-echo");
406
178
fprintf(stderr, "Waiting for input from stdin \n");
411
fprintf(stderr, "Interrupted by signal, exiting.\n");
413
182
status = EXIT_FAILURE;
418
fprintf(stderr, "%s ", prefix);
421
const char *cryptsource = getenv("CRYPTTAB_SOURCE");
422
const char *crypttarget = getenv("CRYPTTAB_NAME");
423
/* Before cryptsetup 1.1.0~rc2 */
424
if(cryptsource == NULL){
425
cryptsource = getenv("cryptsource");
427
if(crypttarget == NULL){
428
crypttarget = getenv("crypttarget");
430
const char *const prompt1 = "Unlocking the disk";
431
const char *const prompt2 = "Enter passphrase";
432
if(cryptsource == NULL){
433
if(crypttarget == NULL){
434
fprintf(stderr, "%s to unlock the disk: ", prompt2);
436
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
440
if(crypttarget == NULL){
441
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
444
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
445
crypttarget, prompt2);
449
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);
451
194
status = EXIT_SUCCESS;
452
/* Make n = data size instead of allocated buffer size */
454
/* Strip final newline */
455
if(n > 0 and buffer[n-1] == '\n'){
456
buffer[n-1] = '\0'; /* not strictly necessary */
461
sret = write(STDOUT_FILENO, buffer + written, n - written);
464
error(0, errno, "write");
476
status = EXIT_FAILURE;
481
written += (size_t)sret;
483
sret = close(STDOUT_FILENO);
486
error(0, errno, "close");
501
if(errno != EINTR and not feof(stdin)){
502
error(0, errno, "getline");
505
status = EX_UNAVAILABLE;
198
if (errno != EINTR and not feof(stdin)){
200
status = EXIT_FAILURE;
515
/* if(sret == 0), then the only sensible thing to do is to retry
516
to read from stdin */
204
/* if(ret == 0), then the only sensible thing to do is to retry to
517
206
fputc('\n', stderr);
518
if(debug and not quit_now){
519
/* If quit_now is nonzero, we were interrupted by a signal, and
520
will print that later, so no need to show this too. */
521
fprintf(stderr, "getline() returned 0, retrying.\n");
528
210
fprintf(stderr, "Restoring terminal attributes\n");
530
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
531
error(0, errno, "tcsetattr+echo");
535
sigemptyset(&old_action.sa_mask);
536
old_action.sa_handler = SIG_DFL;
537
ret = sigaction(signal_received, &old_action, NULL);
539
error(0, errno, "sigaction");
541
raise(signal_received);
545
fprintf(stderr, "%s is exiting with status %d\n", argv[0],
548
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]);