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,
37
#include <stddef.h> /* NULL, size_t, ssize_t */
38
#include <sys/types.h> /* ssize_t, struct dirent, pid_t,
35
SIGQUIT, SIGHUP, SIGTERM */
36
#include <stddef.h> /* NULL, size_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()
56
#include <argp.h> /* struct argp_option, struct
57
argp_state, struct argp,
58
argp_parse(), error_t,
59
ARGP_KEY_ARG, ARGP_KEY_END,
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(), ... */
46
#include <string.h> /* strlen, rindex, strncmp, strcmp */
47
#include <argp.h> /* struct argp_option,
48
struct argp_state, struct argp,
66
volatile sig_atomic_t quit_now = 0;
51
volatile bool quit_now = false;
68
52
bool debug = false;
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const char *argp_program_version = "password-prompt " VERSION;
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const char *argp_program_bug_address = "<mandos@recompile.se>";
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/* Needed for conflict resolution */
73
const char plymouth_name[] = "plymouthd";
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/* Function to use when printing errors */
76
__attribute__((format (gnu_printf, 3, 4)))
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void error_plus(int status, int errnum, const char *formatstring,
83
va_start(ap, formatstring);
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ret = vasprintf(&text, formatstring, ap);
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fprintf(stderr, "Mandos plugin %s: ",
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program_invocation_short_name);
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vfprintf(stderr, formatstring, ap);
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fprintf(stderr, ": %s\n", strerror(errnum));
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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
__attribute__((nonnull))
113
int is_plymouth(const struct dirent *proc_entry){
120
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
122
if(errno != 0 or *tmp != '\0'
123
or proc_id != (uintmax_t)((pid_t)proc_id)){
128
char *cmdline_filename;
129
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
132
error_plus(0, errno, "asprintf");
136
/* Open /proc/<pid>/cmdline */
137
cl_fd = open(cmdline_filename, O_RDONLY);
138
free(cmdline_filename);
141
error_plus(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_plus(0, errno, "realloc");
164
cmdline_allocated += blocksize;
168
sret = read(cl_fd, cmdline + cmdline_len,
169
cmdline_allocated - cmdline_len);
171
error_plus(0, errno, "read");
176
cmdline_len += (size_t)sret;
180
error_plus(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_plus(1, errno, "scandir");
53
const char *argp_program_version = "passprompt 0.9";
54
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
56
static void termination_handler(__attribute__((unused))int signum){
229
60
int main(int argc, char **argv){
233
63
struct termios t_new, t_old;
234
64
char *buffer = NULL;
241
71
struct argp_option options[] = {
242
72
{ .name = "prefix", .key = 'p',
243
73
.arg = "PREFIX", .flags = 0,
244
.doc = "Prefix shown before the prompt", .group = 2 },
74
.doc = "Prefix used before the passprompt", .group = 2 },
245
75
{ .name = "debug", .key = 128,
246
76
.doc = "Debug mode", .group = 3 },
248
* These reproduce what we would get without ARGP_NO_HELP
250
{ .name = "help", .key = '?',
251
.doc = "Give this help list", .group = -1 },
252
{ .name = "usage", .key = -3,
253
.doc = "Give a short usage message", .group = -1 },
254
{ .name = "version", .key = 'V',
255
.doc = "Print program version", .group = -1 },
259
__attribute__((nonnull(3)))
260
error_t parse_opt (int key, char *arg, struct argp_state *state){
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. */
270
* These reproduce what we would get without ARGP_NO_HELP
272
case '?': /* --help */
273
argp_state_help(state, state->out_stream,
274
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
275
& ~(unsigned int)ARGP_HELP_EXIT_OK);
276
case -3: /* --usage */
277
argp_state_help(state, state->out_stream,
278
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
279
case 'V': /* --version */
280
fprintf(state->out_stream, "%s\n", argp_program_version);
281
exit(argp_err_exit_status);
284
96
return ARGP_ERR_UNKNOWN;
289
101
struct argp argp = { .options = options, .parser = parse_opt,
291
.doc = "Mandos password-prompt -- Read and"
292
" output a password" };
293
ret = argp_parse(&argp, argc, argv,
294
ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
301
error_plus(0, errno, "argp_parse");
103
.doc = "Mandos Passprompt -- Provides a passprompt" };
104
argp_parse (&argp, argc, argv, 0, 0, NULL);
309
108
fprintf(stderr, "Starting %s\n", argv[0]);
312
if(conflict_detection()){
314
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
320
111
fprintf(stderr, "Storing current terminal attributes\n");
323
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
325
error_plus(0, errno, "tcgetattr");
329
return EX_UNAVAILABLE;
114
if (tcgetattr(STDIN_FILENO, &t_old) != 0){
335
118
sigemptyset(&new_action.sa_mask);
336
ret = sigaddset(&new_action.sa_mask, SIGINT);
338
error_plus(0, errno, "sigaddset");
341
ret = sigaddset(&new_action.sa_mask, SIGHUP);
343
error_plus(0, errno, "sigaddset");
346
ret = sigaddset(&new_action.sa_mask, SIGTERM);
348
error_plus(0, errno, "sigaddset");
351
/* Need to check if the handler is SIG_IGN before handling:
352
| [[info:libc:Initial Signal Actions]] |
353
| [[info:libc:Basic Signal Handling]] |
355
ret = sigaction(SIGINT, NULL, &old_action);
357
error_plus(0, errno, "sigaction");
360
if(old_action.sa_handler != SIG_IGN){
361
ret = sigaction(SIGINT, &new_action, NULL);
363
error_plus(0, errno, "sigaction");
367
ret = sigaction(SIGHUP, NULL, &old_action);
369
error_plus(0, errno, "sigaction");
372
if(old_action.sa_handler != SIG_IGN){
373
ret = sigaction(SIGHUP, &new_action, NULL);
375
error_plus(0, errno, "sigaction");
379
ret = sigaction(SIGTERM, NULL, &old_action);
381
error_plus(0, errno, "sigaction");
384
if(old_action.sa_handler != SIG_IGN){
385
ret = sigaction(SIGTERM, &new_action, NULL);
387
error_plus(0, errno, "sigaction");
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);
394
134
fprintf(stderr, "Removing echo flag from terminal attributes\n");
398
t_new.c_lflag &= ~(tcflag_t)ECHO;
399
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
401
error_plus(0, errno, "tcsetattr-echo");
405
return EX_UNAVAILABLE;
138
t_new.c_lflag &= ~ECHO;
139
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
140
perror("tcsetattr-echo");
413
145
fprintf(stderr, "Waiting for input from stdin \n");
418
fprintf(stderr, "Interrupted by signal, exiting.\n");
420
149
status = EXIT_FAILURE;
425
fprintf(stderr, "%s ", prefix);
428
const char *cryptsource = getenv("CRYPTTAB_SOURCE");
429
const char *crypttarget = getenv("CRYPTTAB_NAME");
430
/* Before cryptsetup 1.1.0~rc2 */
431
if(cryptsource == NULL){
432
cryptsource = getenv("cryptsource");
434
if(crypttarget == NULL){
435
crypttarget = getenv("crypttarget");
437
const char *const prompt1 = "Unlocking the disk";
438
const char *const prompt2 = "Enter passphrase";
439
if(cryptsource == NULL){
440
if(crypttarget == NULL){
441
fprintf(stderr, "%s to unlock the disk: ", prompt2);
443
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
447
if(crypttarget == NULL){
448
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
451
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
452
crypttarget, prompt2);
456
sret = getline(&buffer, &n, stdin);
154
fprintf(stderr, "%s Password: ", prefix);
156
fprintf(stderr, "Password: ");
158
ret = getline(&buffer, &n, stdin);
160
fprintf(stdout, "%s", buffer);
458
161
status = EXIT_SUCCESS;
459
/* Make n = data size instead of allocated buffer size */
461
/* Strip final newline */
462
if(n > 0 and buffer[n-1] == '\n'){
463
buffer[n-1] = '\0'; /* not strictly necessary */
468
sret = write(STDOUT_FILENO, buffer + written, n - written);
471
error_plus(0, errno, "write");
483
status = EXIT_FAILURE;
488
written += (size_t)sret;
490
sret = close(STDOUT_FILENO);
493
error_plus(0, errno, "close");
508
if(errno != EINTR and not feof(stdin)){
509
error_plus(0, errno, "getline");
512
status = EX_UNAVAILABLE;
165
if (errno != EINTR and not feof(stdin)){
167
status = EXIT_FAILURE;
523
/* if(sret == 0), then the only sensible thing to do is to retry
524
to read from stdin */
171
/* if(ret == 0), then the only sensible thing to do is to retry to
525
173
fputc('\n', stderr);
526
if(debug and not quit_now){
527
/* If quit_now is nonzero, we were interrupted by a signal, and
528
will print that later, so no need to show this too. */
529
fprintf(stderr, "getline() returned 0, retrying.\n");
536
177
fprintf(stderr, "Restoring terminal attributes\n");
538
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
539
error_plus(0, errno, "tcsetattr+echo");
543
sigemptyset(&old_action.sa_mask);
544
old_action.sa_handler = SIG_DFL;
545
ret = sigaction(signal_received, &old_action, NULL);
547
error_plus(0, errno, "sigaction");
549
raise(signal_received);
553
fprintf(stderr, "%s is exiting with status %d\n", argv[0],
556
if(status == EXIT_SUCCESS or status == EX_OK){
179
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
180
perror("tcsetattr+echo");
184
fprintf(stderr, "%s is exiting\n", argv[0]);