1
/* -*- coding: utf-8; mode: c; mode: orgtbl -*- */
3
* Password-prompt - Read a password from the terminal and print it
5
* Copyright © 2008-2018 Teddy Hogeborn
6
* Copyright © 2008-2018 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
16
* WITHOUT ANY WARRANTY; without even the implied warranty of
17
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18
* General Public License for more details.
20
* You should have received a copy of the GNU General Public License
21
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
23
* Contact the authors at <mandos@recompile.se>.
26
#define _GNU_SOURCE /* getline(), asprintf() */
28
#include <termios.h> /* struct termios, tcsetattr(),
29
TCSAFLUSH, tcgetattr(), ECHO */
30
#include <unistd.h> /* struct termios, tcsetattr(),
31
STDIN_FILENO, TCSAFLUSH,
32
tcgetattr(), ECHO, readlink() */
33
#include <signal.h> /* sig_atomic_t, raise(), struct
34
sigaction, sigemptyset(),
35
sigaction(), sigaddset(), SIGINT,
36
SIGQUIT, SIGHUP, SIGTERM,
38
#include <stddef.h> /* NULL, size_t, ssize_t */
39
#include <sys/types.h> /* ssize_t, struct dirent, pid_t,
41
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
43
#include <dirent.h> /* scandir(), alphasort() */
44
#include <stdio.h> /* fprintf(), stderr, getline(),
45
stdin, feof(), fputc(), vfprintf(),
47
#include <errno.h> /* errno, EBADF, ENOTTY, EINVAL,
48
EFAULT, EFBIG, EIO, ENOSPC, EINTR
50
#include <error.h> /* error() */
51
#include <iso646.h> /* or, not */
52
#include <stdbool.h> /* bool, false, true */
53
#include <inttypes.h> /* strtoumax() */
54
#include <sys/stat.h> /* struct stat, lstat(), open() */
55
#include <string.h> /* strlen, rindex, memcmp, strerror()
57
#include <argp.h> /* struct argp_option, struct
58
argp_state, struct argp,
59
argp_parse(), error_t,
60
ARGP_KEY_ARG, ARGP_KEY_END,
62
#include <sysexits.h> /* EX_SOFTWARE, EX_OSERR,
63
EX_UNAVAILABLE, EX_IOERR, EX_OK */
64
#include <fcntl.h> /* open() */
65
#include <stdarg.h> /* va_list, va_start(), ... */
67
volatile sig_atomic_t quit_now = 0;
70
const char *argp_program_version = "password-prompt " VERSION;
71
const char *argp_program_bug_address = "<mandos@recompile.se>";
73
/* Needed for conflict resolution */
74
const char plymouth_name[] = "plymouthd";
76
/* Function to use when printing errors */
77
__attribute__((format (gnu_printf, 3, 4)))
78
void error_plus(int status, int errnum, const char *formatstring,
84
va_start(ap, formatstring);
85
ret = vasprintf(&text, formatstring, ap);
87
fprintf(stderr, "Mandos plugin %s: ",
88
program_invocation_short_name);
89
vfprintf(stderr, formatstring, ap);
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
__attribute__((nonnull))
114
int is_plymouth(const struct dirent *proc_entry){
121
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
123
if(errno != 0 or *tmp != '\0'
124
or proc_id != (uintmax_t)((pid_t)proc_id)){
129
char *cmdline_filename;
130
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
133
error_plus(0, errno, "asprintf");
137
/* Open /proc/<pid>/cmdline */
138
cl_fd = open(cmdline_filename, O_RDONLY);
139
free(cmdline_filename);
142
error_plus(0, errno, "open");
147
char *cmdline = NULL;
149
size_t cmdline_len = 0;
150
size_t cmdline_allocated = 0;
152
const size_t blocksize = 1024;
155
/* Allocate more space? */
156
if(cmdline_len + blocksize + 1 > cmdline_allocated){
157
tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
159
error_plus(0, errno, "realloc");
165
cmdline_allocated += blocksize;
169
sret = read(cl_fd, cmdline + cmdline_len,
170
cmdline_allocated - cmdline_len);
172
error_plus(0, errno, "read");
177
cmdline_len += (size_t)sret;
181
error_plus(0, errno, "close");
185
cmdline[cmdline_len] = '\0'; /* Make sure it is terminated */
187
/* we now have cmdline */
190
char *cmdline_base = strrchr(cmdline, '/');
191
if(cmdline_base != NULL){
192
cmdline_base += 1; /* skip the slash */
194
cmdline_base = cmdline;
197
if(strcmp(cmdline_base, plymouth_name) != 0){
199
fprintf(stderr, "\"%s\" is not \"%s\"\n", cmdline_base,
206
fprintf(stderr, "\"%s\" equals \"%s\"\n", cmdline_base,
213
struct dirent **direntries = NULL;
215
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
217
error_plus(1, errno, "scandir");
230
int main(int argc, char **argv){
234
struct termios t_new, t_old;
237
int status = EXIT_SUCCESS;
238
struct sigaction old_action,
239
new_action = { .sa_handler = termination_handler,
242
struct argp_option options[] = {
243
{ .name = "prefix", .key = 'p',
244
.arg = "PREFIX", .flags = 0,
245
.doc = "Prefix shown before the prompt", .group = 2 },
246
{ .name = "debug", .key = 128,
247
.doc = "Debug mode", .group = 3 },
249
* These reproduce what we would get without ARGP_NO_HELP
251
{ .name = "help", .key = '?',
252
.doc = "Give this help list", .group = -1 },
253
{ .name = "usage", .key = -3,
254
.doc = "Give a short usage message", .group = -1 },
255
{ .name = "version", .key = 'V',
256
.doc = "Print program version", .group = -1 },
260
__attribute__((nonnull(3)))
261
error_t parse_opt (int key, char *arg, struct argp_state *state){
271
* These reproduce what we would get without ARGP_NO_HELP
273
case '?': /* --help */
274
argp_state_help(state, state->out_stream,
275
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
276
& ~(unsigned int)ARGP_HELP_EXIT_OK);
277
case -3: /* --usage */
278
argp_state_help(state, state->out_stream,
279
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
280
case 'V': /* --version */
281
fprintf(state->out_stream, "%s\n", argp_program_version);
282
exit(argp_err_exit_status);
285
return ARGP_ERR_UNKNOWN;
290
struct argp argp = { .options = options, .parser = parse_opt,
292
.doc = "Mandos password-prompt -- Read and"
293
" output a password" };
294
ret = argp_parse(&argp, argc, argv,
295
ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
302
error_plus(0, errno, "argp_parse");
310
fprintf(stderr, "Starting %s\n", argv[0]);
313
if(conflict_detection()){
315
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
321
fprintf(stderr, "Storing current terminal attributes\n");
324
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
326
error_plus(0, errno, "tcgetattr");
330
return EX_UNAVAILABLE;
336
sigemptyset(&new_action.sa_mask);
337
ret = sigaddset(&new_action.sa_mask, SIGINT);
339
error_plus(0, errno, "sigaddset");
342
ret = sigaddset(&new_action.sa_mask, SIGHUP);
344
error_plus(0, errno, "sigaddset");
347
ret = sigaddset(&new_action.sa_mask, SIGTERM);
349
error_plus(0, errno, "sigaddset");
352
/* Need to check if the handler is SIG_IGN before handling:
353
| [[info:libc:Initial Signal Actions]] |
354
| [[info:libc:Basic Signal Handling]] |
356
ret = sigaction(SIGINT, NULL, &old_action);
358
error_plus(0, errno, "sigaction");
361
if(old_action.sa_handler != SIG_IGN){
362
ret = sigaction(SIGINT, &new_action, NULL);
364
error_plus(0, errno, "sigaction");
368
ret = sigaction(SIGHUP, NULL, &old_action);
370
error_plus(0, errno, "sigaction");
373
if(old_action.sa_handler != SIG_IGN){
374
ret = sigaction(SIGHUP, &new_action, NULL);
376
error_plus(0, errno, "sigaction");
380
ret = sigaction(SIGTERM, NULL, &old_action);
382
error_plus(0, errno, "sigaction");
385
if(old_action.sa_handler != SIG_IGN){
386
ret = sigaction(SIGTERM, &new_action, NULL);
388
error_plus(0, errno, "sigaction");
395
fprintf(stderr, "Removing echo flag from terminal attributes\n");
399
t_new.c_lflag &= ~(tcflag_t)ECHO;
400
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
402
error_plus(0, errno, "tcsetattr-echo");
406
return EX_UNAVAILABLE;
414
fprintf(stderr, "Waiting for input from stdin \n");
419
fprintf(stderr, "Interrupted by signal, exiting.\n");
421
status = EXIT_FAILURE;
426
fprintf(stderr, "%s ", prefix);
429
const char *cryptsource = getenv("CRYPTTAB_SOURCE");
430
const char *crypttarget = getenv("CRYPTTAB_NAME");
431
/* Before cryptsetup 1.1.0~rc2 */
432
if(cryptsource == NULL){
433
cryptsource = getenv("cryptsource");
435
if(crypttarget == NULL){
436
crypttarget = getenv("crypttarget");
438
const char *const prompt1 = "Unlocking the disk";
439
const char *const prompt2 = "Enter passphrase";
440
if(cryptsource == NULL){
441
if(crypttarget == NULL){
442
fprintf(stderr, "%s to unlock the disk: ", prompt2);
444
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
448
if(crypttarget == NULL){
449
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
452
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
453
crypttarget, prompt2);
457
sret = getline(&buffer, &n, stdin);
459
status = EXIT_SUCCESS;
460
/* Make n = data size instead of allocated buffer size */
462
/* Strip final newline */
463
if(n > 0 and buffer[n-1] == '\n'){
464
buffer[n-1] = '\0'; /* not strictly necessary */
469
sret = write(STDOUT_FILENO, buffer + written, n - written);
472
error_plus(0, errno, "write");
484
status = EXIT_FAILURE;
489
written += (size_t)sret;
491
sret = close(STDOUT_FILENO);
494
error_plus(0, errno, "close");
509
if(errno != EINTR and not feof(stdin)){
510
error_plus(0, errno, "getline");
513
status = EX_UNAVAILABLE;
524
/* if(sret == 0), then the only sensible thing to do is to retry
525
to read from stdin */
527
if(debug and not quit_now){
528
/* If quit_now is nonzero, we were interrupted by a signal, and
529
will print that later, so no need to show this too. */
530
fprintf(stderr, "getline() returned 0, retrying.\n");
537
fprintf(stderr, "Restoring terminal attributes\n");
539
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
540
error_plus(0, errno, "tcsetattr+echo");
544
sigemptyset(&old_action.sa_mask);
545
old_action.sa_handler = SIG_DFL;
546
ret = sigaction(signal_received, &old_action, NULL);
548
error_plus(0, errno, "sigaction");
550
raise(signal_received);
554
fprintf(stderr, "%s is exiting with status %d\n", argv[0],
557
if(status == EXIT_SUCCESS or status == EX_OK){
added
removed
plugins.d/password-prompt.c
