1
/* -*- coding: utf-8 -*- */
3
* Passprompt - Read a password from the terminal and print it
5
* Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
7
* This program is free software: you can redistribute it and/or
8
* modify it under the terms of the GNU General Public License as
9
* published by the Free Software Foundation, either version 3 of the
10
* License, or (at your option) any later version.
12
* This program is distributed in the hope that it will be useful, but
13
* WITHOUT ANY WARRANTY; without even the implied warranty of
14
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15
* General Public License for more details.
17
* You should have received a copy of the GNU General Public License
18
* along with this program. If not, see
19
* <http://www.gnu.org/licenses/>.
21
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
22
* <https://www.fukt.bsnet.se/~teddy/>.
25
1
#define _GNU_SOURCE /* getline() */
2
#define _FORTIFY_SOURCE 2
27
3
#include <termios.h> /* struct termios, tcsetattr(),
28
4
TCSAFLUSH, tcgetattr(), ECHO */
29
5
#include <unistd.h> /* struct termios, tcsetattr(),
33
9
sigaction, sigemptyset(),
34
10
sigaction(), sigaddset(), SIGINT,
35
11
SIGQUIT, SIGHUP, SIGTERM */
36
#include <stddef.h> /* NULL, size_t, ssize_t */
12
#include <stddef.h> /* NULL, size_t */
37
13
#include <sys/types.h> /* ssize_t */
38
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
39
getopt_long, getenv() */
14
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE */
40
15
#include <stdio.h> /* fprintf(), stderr, getline(),
41
16
stdin, feof(), perror(), fputc(),
42
stdout, getopt_long */
43
18
#include <errno.h> /* errno, EINVAL */
44
19
#include <iso646.h> /* or, not */
45
20
#include <stdbool.h> /* bool, false, true */
46
#include <string.h> /* strlen, rindex, strncmp, strcmp */
47
#include <argp.h> /* struct argp_option, struct
48
argp_state, struct argp,
49
argp_parse(), error_t,
50
ARGP_KEY_ARG, ARGP_KEY_END,
53
22
volatile bool quit_now = false;
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){
24
void termination_handler(int signum){
62
28
int main(int argc, char **argv){
65
31
struct termios t_new, t_old;
66
32
char *buffer = NULL;
68
33
int status = EXIT_SUCCESS;
69
34
struct sigaction old_action,
70
35
new_action = { .sa_handler = termination_handler,
73
struct argp_option options[] = {
74
{ .name = "prefix", .key = 'p',
75
.arg = "PREFIX", .flags = 0,
76
.doc = "Prefix shown before the prompt", .group = 2 },
77
{ .name = "debug", .key = 128,
78
.doc = "Debug mode", .group = 3 },
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. */
98
return ARGP_ERR_UNKNOWN;
103
struct argp argp = { .options = options, .parser = parse_opt,
105
.doc = "Mandos password-prompt -- Read and"
106
" output a password" };
107
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
108
if (ret == ARGP_ERR_UNKNOWN){
109
fprintf(stderr, "Unknown error while parsing arguments\n");
115
fprintf(stderr, "Starting %s\n", argv[0]);
118
fprintf(stderr, "Storing current terminal attributes\n");
121
38
if (tcgetattr(STDIN_FILENO, &t_old) != 0){
123
39
return EXIT_FAILURE;
126
42
sigemptyset(&new_action.sa_mask);
127
43
sigaddset(&new_action.sa_mask, SIGINT);
44
sigaddset(&new_action.sa_mask, SIGQUIT);
128
45
sigaddset(&new_action.sa_mask, SIGHUP);
129
46
sigaddset(&new_action.sa_mask, SIGTERM);
130
ret = sigaction(SIGINT, NULL, &old_action);
135
if (old_action.sa_handler != SIG_IGN){
136
ret = sigaction(SIGINT, &new_action, NULL);
142
ret = sigaction(SIGHUP, NULL, &old_action);
147
if (old_action.sa_handler != SIG_IGN){
148
ret = sigaction(SIGHUP, &new_action, NULL);
154
ret = sigaction(SIGTERM, NULL, &old_action);
159
if (old_action.sa_handler != SIG_IGN){
160
ret = sigaction(SIGTERM, &new_action, NULL);
169
fprintf(stderr, "Removing echo flag from terminal attributes\n");
47
sigaction(SIGINT, NULL, &old_action);
48
if (old_action.sa_handler != SIG_IGN)
49
sigaction(SIGINT, &new_action, NULL);
50
sigaction(SIGQUIT, NULL, &old_action);
51
if (old_action.sa_handler != SIG_IGN)
52
sigaction(SIGQUIT, &new_action, NULL);
53
sigaction(SIGHUP, NULL, &old_action);
54
if (old_action.sa_handler != SIG_IGN)
55
sigaction(SIGHUP, &new_action, NULL);
56
sigaction(SIGTERM, NULL, &old_action);
57
if (old_action.sa_handler != SIG_IGN)
58
sigaction(SIGTERM, &new_action, NULL);
173
61
t_new.c_lflag &= ~ECHO;
175
63
perror("tcsetattr-echo");
176
64
return EXIT_FAILURE;
180
fprintf(stderr, "Waiting for input from stdin \n");
185
fprintf(stderr, "Interrupted by signal, exiting.\n");
187
69
status = EXIT_FAILURE;
192
fprintf(stderr, "%s ", prefix);
195
const char *cryptsource = getenv("cryptsource");
196
const char *crypttarget = getenv("crypttarget");
197
const char *const prompt
198
= "Enter passphrase to unlock the disk";
199
if(cryptsource == NULL){
200
if(crypttarget == NULL){
201
fprintf(stderr, "%s: ", prompt);
203
fprintf(stderr, "%s (%s): ", prompt, crypttarget);
206
if(crypttarget == NULL){
207
fprintf(stderr, "%s %s: ", prompt, cryptsource);
209
fprintf(stderr, "%s %s (%s): ", prompt, cryptsource,
72
fprintf(stderr, "Password: ");
214
73
ret = getline(&buffer, &n, stdin);
75
fprintf(stdout, "%s", buffer);
216
76
status = EXIT_SUCCESS;
217
/* Make n = data size instead of allocated buffer size */
219
/* Strip final newline */
220
if(n>0 and buffer[n-1] == '\n'){
221
buffer[n-1] = '\0'; /* not strictly necessary */
226
ret = write(STDOUT_FILENO, buffer + written, n - written);
229
status = EXIT_FAILURE;
232
written += (size_t)ret;
79
// ret == 0 makes no other sence than to retry to read from stdin
237
81
if (errno != EINTR and not feof(stdin)){
238
82
perror("getline");