3
3
* Password-prompt - Read a password from the terminal and print it
5
* Copyright © 2008-2010 Teddy Hogeborn
6
* Copyright © 2008-2010 Björn Påhlsson
5
* Copyright © 2008-2016 Teddy Hogeborn
6
* Copyright © 2008-2016 Björn Påhlsson
8
8
* This program is free software: you can redistribute it and/or
9
9
* modify it under the terms of the GNU General Public License as
19
19
* along with this program. If not, see
20
20
* <http://www.gnu.org/licenses/>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
22
* Contact the authors at <mandos@recompile.se>.
25
25
#define _GNU_SOURCE /* getline(), asprintf() */
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,
41
41
getenv(), free() */
42
42
#include <dirent.h> /* scandir(), alphasort() */
43
43
#include <stdio.h> /* fprintf(), stderr, getline(),
44
stdin, feof(), fputc()
44
stdin, feof(), fputc(), vfprintf(),
46
46
#include <errno.h> /* errno, EBADF, ENOTTY, EINVAL,
47
47
EFAULT, EFBIG, EIO, ENOSPC, EINTR
50
50
#include <iso646.h> /* or, not */
51
51
#include <stdbool.h> /* bool, false, true */
52
52
#include <inttypes.h> /* strtoumax() */
53
#include <sys/stat.h> /* struct stat, lstat(), open() */
54
#include <string.h> /* strlen, rindex, memcmp */
53
#include <sys/stat.h> /* struct stat, lstat(), open() */
54
#include <string.h> /* strlen, rindex, memcmp, strerror()
55
56
#include <argp.h> /* struct argp_option, struct
56
57
argp_state, struct argp,
57
58
argp_parse(), error_t,
60
61
#include <sysexits.h> /* EX_SOFTWARE, EX_OSERR,
61
62
EX_UNAVAILABLE, EX_IOERR, EX_OK */
62
63
#include <fcntl.h> /* open() */
64
#include <stdarg.h> /* va_list, va_start(), ... */
64
66
volatile sig_atomic_t quit_now = 0;
65
67
int signal_received;
66
68
bool debug = false;
67
69
const char *argp_program_version = "password-prompt " VERSION;
68
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
70
const char *argp_program_bug_address = "<mandos@recompile.se>";
70
72
/* Needed for conflict resolution */
71
73
const char plymouth_name[] = "plymouthd";
72
const char plymouth_alt_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, ": %s\n", strerror(errnum));
90
error(status, errno, "vasprintf while printing error");
93
fprintf(stderr, "Mandos plugin ");
94
error(status, errnum, "%s", text);
75
98
static void termination_handler(int signum){
86
109
from the terminal. Password-prompt will exit if it detects
87
110
plymouth since plymouth performs the same functionality.
112
__attribute__((nonnull))
89
113
int is_plymouth(const struct dirent *proc_entry){
96
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
120
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
98
122
if(errno != 0 or *tmp != '\0'
99
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
123
or proc_id != (uintmax_t)((pid_t)proc_id)){
104
128
char *cmdline_filename;
105
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline", proc_entry->d_name);
129
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
107
error(0, errno, "asprintf");
132
error_plus(0, errno, "asprintf");
111
/* Open /proc/<pid>/cmdline */
136
/* Open /proc/<pid>/cmdline */
112
137
cl_fd = open(cmdline_filename, O_RDONLY);
113
138
free(cmdline_filename);
115
error(0, errno, "open");
141
error_plus(0, errno, "open");
128
155
if(cmdline_len + blocksize + 1 > cmdline_allocated){
129
156
tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
131
error(0, errno, "realloc");
158
error_plus(0, errno, "realloc");
141
168
sret = read(cl_fd, cmdline + cmdline_len,
142
169
cmdline_allocated - cmdline_len);
144
error(0, errno, "read");
171
error_plus(0, errno, "read");
166
193
cmdline_base = cmdline;
169
if((strcmp(cmdline_base, plymouth_name) != 0)
170
and (strcmp(cmdline_base, plymouth_alt_name) != 0)){
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,
178
struct dirent **direntries;
212
struct dirent **direntries = NULL;
180
214
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
182
error(1, errno, "scandir");
216
error_plus(1, errno, "scandir");
267
303
fprintf(stderr, "Starting %s\n", argv[0]);
270
if (conflict_detection()){
306
if(conflict_detection()){
272
fprintf(stderr, "Stopping %s because of conflict", argv[0]);
308
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
274
310
return EXIT_FAILURE;
281
317
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
283
error(0, errno, "tcgetattr");
319
error_plus(0, errno, "tcgetattr");
293
329
sigemptyset(&new_action.sa_mask);
294
330
ret = sigaddset(&new_action.sa_mask, SIGINT);
296
error(0, errno, "sigaddset");
332
error_plus(0, errno, "sigaddset");
299
335
ret = sigaddset(&new_action.sa_mask, SIGHUP);
301
error(0, errno, "sigaddset");
337
error_plus(0, errno, "sigaddset");
304
340
ret = sigaddset(&new_action.sa_mask, SIGTERM);
306
error(0, errno, "sigaddset");
342
error_plus(0, errno, "sigaddset");
309
345
/* Need to check if the handler is SIG_IGN before handling:
313
349
ret = sigaction(SIGINT, NULL, &old_action);
315
error(0, errno, "sigaction");
351
error_plus(0, errno, "sigaction");
318
354
if(old_action.sa_handler != SIG_IGN){
319
355
ret = sigaction(SIGINT, &new_action, NULL);
321
error(0, errno, "sigaction");
357
error_plus(0, errno, "sigaction");
325
361
ret = sigaction(SIGHUP, NULL, &old_action);
327
error(0, errno, "sigaction");
363
error_plus(0, errno, "sigaction");
330
366
if(old_action.sa_handler != SIG_IGN){
331
367
ret = sigaction(SIGHUP, &new_action, NULL);
333
error(0, errno, "sigaction");
369
error_plus(0, errno, "sigaction");
337
373
ret = sigaction(SIGTERM, NULL, &old_action);
339
error(0, errno, "sigaction");
375
error_plus(0, errno, "sigaction");
342
378
if(old_action.sa_handler != SIG_IGN){
343
379
ret = sigaction(SIGTERM, &new_action, NULL);
345
error(0, errno, "sigaction");
381
error_plus(0, errno, "sigaction");
356
392
t_new.c_lflag &= ~(tcflag_t)ECHO;
357
393
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
359
error(0, errno, "tcsetattr-echo");
395
error_plus(0, errno, "tcsetattr-echo");
426
462
sret = write(STDOUT_FILENO, buffer + written, n - written);
429
error(0, errno, "write");
465
error_plus(0, errno, "write");
448
484
sret = close(STDOUT_FILENO);
451
error(0, errno, "close");
487
error_plus(0, errno, "close");
454
490
status = EX_OSFILE;
466
502
if(errno != EINTR and not feof(stdin)){
467
error(0, errno, "getline");
503
error_plus(0, errno, "getline");
470
506
status = EX_UNAVAILABLE;
480
/* if(sret == 0), then the only sensible thing to do is to retry to
517
/* if(sret == 0), then the only sensible thing to do is to retry
518
to read from stdin */
482
519
fputc('\n', stderr);
483
520
if(debug and not quit_now){
484
521
/* If quit_now is nonzero, we were interrupted by a signal, and
493
530
fprintf(stderr, "Restoring terminal attributes\n");
495
532
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
496
error(0, errno, "tcsetattr+echo");
533
error_plus(0, errno, "tcsetattr+echo");
501
538
old_action.sa_handler = SIG_DFL;
502
539
ret = sigaction(signal_received, &old_action, NULL);
504
error(0, errno, "sigaction");
541
error_plus(0, errno, "sigaction");
506
543
raise(signal_received);