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 © 2008-2014 Teddy Hogeborn
6
* Copyright © 2008-2014 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
/* Needed for conflic resolution */
71
const char plymouthd_name[] = "plymouthd";
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, ": %s\n", strerror(errnum));
90
error(status, errno, "vasprintf while printing error");
93
fprintf(stderr, "Mandos plugin ");
94
error(status, errnum, "%s", text);
74
98
static void termination_handler(int signum){
85
109
from the terminal. Password-prompt will exit if it detects
86
110
plymouth since plymouth performs the same functionality.
112
__attribute__((nonnull))
88
113
int is_plymouth(const struct dirent *proc_entry){
95
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
120
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
97
122
if(errno != 0 or *tmp != '\0'
98
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
123
or proc_id != (uintmax_t)((pid_t)proc_id)){
103
128
char *cmdline_filename;
104
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline", proc_entry->d_name);
129
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
106
error(0, errno, "asprintf");
132
error_plus(0, errno, "asprintf");
110
/* Open /proc/<pid>/cmdline */
136
/* Open /proc/<pid>/cmdline */
111
137
cl_fd = open(cmdline_filename, O_RDONLY);
112
138
free(cmdline_filename);
114
error(0, errno, "open");
141
error_plus(0, errno, "open");
127
155
if(cmdline_len + blocksize + 1 > cmdline_allocated){
128
156
tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
130
error(0, errno, "realloc");
158
error_plus(0, errno, "realloc");
140
168
sret = read(cl_fd, cmdline + cmdline_len,
141
169
cmdline_allocated - cmdline_len);
143
error(0, errno, "read");
171
error_plus(0, errno, "read");
165
193
cmdline_base = cmdline;
168
if(strcmp(cmdline_base, plymouthd_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,
176
struct dirent **direntries;
212
struct dirent **direntries = NULL;
178
214
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
180
error(1, errno, "scandir");
216
error_plus(1, errno, "scandir");
265
303
fprintf(stderr, "Starting %s\n", argv[0]);
268
if (conflict_detection()){
306
if(conflict_detection()){
270
fprintf(stderr, "Stopping %s because of conflict", argv[0]);
308
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
272
310
return EXIT_FAILURE;
279
317
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
281
error(0, errno, "tcgetattr");
319
error_plus(0, errno, "tcgetattr");
291
329
sigemptyset(&new_action.sa_mask);
292
330
ret = sigaddset(&new_action.sa_mask, SIGINT);
294
error(0, errno, "sigaddset");
332
error_plus(0, errno, "sigaddset");
297
335
ret = sigaddset(&new_action.sa_mask, SIGHUP);
299
error(0, errno, "sigaddset");
337
error_plus(0, errno, "sigaddset");
302
340
ret = sigaddset(&new_action.sa_mask, SIGTERM);
304
error(0, errno, "sigaddset");
342
error_plus(0, errno, "sigaddset");
307
345
/* Need to check if the handler is SIG_IGN before handling:
311
349
ret = sigaction(SIGINT, NULL, &old_action);
313
error(0, errno, "sigaction");
351
error_plus(0, errno, "sigaction");
316
354
if(old_action.sa_handler != SIG_IGN){
317
355
ret = sigaction(SIGINT, &new_action, NULL);
319
error(0, errno, "sigaction");
357
error_plus(0, errno, "sigaction");
323
361
ret = sigaction(SIGHUP, NULL, &old_action);
325
error(0, errno, "sigaction");
363
error_plus(0, errno, "sigaction");
328
366
if(old_action.sa_handler != SIG_IGN){
329
367
ret = sigaction(SIGHUP, &new_action, NULL);
331
error(0, errno, "sigaction");
369
error_plus(0, errno, "sigaction");
335
373
ret = sigaction(SIGTERM, NULL, &old_action);
337
error(0, errno, "sigaction");
375
error_plus(0, errno, "sigaction");
340
378
if(old_action.sa_handler != SIG_IGN){
341
379
ret = sigaction(SIGTERM, &new_action, NULL);
343
error(0, errno, "sigaction");
381
error_plus(0, errno, "sigaction");
354
392
t_new.c_lflag &= ~(tcflag_t)ECHO;
355
393
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
357
error(0, errno, "tcsetattr-echo");
395
error_plus(0, errno, "tcsetattr-echo");
424
462
sret = write(STDOUT_FILENO, buffer + written, n - written);
427
error(0, errno, "write");
465
error_plus(0, errno, "write");
446
484
sret = close(STDOUT_FILENO);
449
error(0, errno, "close");
487
error_plus(0, errno, "close");
452
490
status = EX_OSFILE;
464
502
if(errno != EINTR and not feof(stdin)){
465
error(0, errno, "getline");
503
error_plus(0, errno, "getline");
468
506
status = EX_UNAVAILABLE;
478
/* 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 */
480
519
fputc('\n', stderr);
481
520
if(debug and not quit_now){
482
521
/* If quit_now is nonzero, we were interrupted by a signal, and
491
530
fprintf(stderr, "Restoring terminal attributes\n");
493
532
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
494
error(0, errno, "tcsetattr+echo");
533
error_plus(0, errno, "tcsetattr+echo");
499
538
old_action.sa_handler = SIG_DFL;
500
539
ret = sigaction(signal_received, &old_action, NULL);
502
error(0, errno, "sigaction");
541
error_plus(0, errno, "sigaction");
504
543
raise(signal_received);