/mandos/release

To get this branch, use:
bzr branch http://bzr.recompile.se/loggerhead/mandos/release
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*  -*- coding: utf-8 -*- */
/*
 * Passprompt - Read a password from the terminal and print it
 *
 * Copyright © 2007-2008 Teddy Hogeborn and Björn Påhlsson.
 * 
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
 * <https://www.fukt.bsnet.se/~teddy/>.
 */

#define _GNU_SOURCE		/* getline() */
#define _FORTIFY_SOURCE 2

#include <termios.h> 		/* struct termios, tcsetattr(),
				   TCSAFLUSH, tcgetattr(), ECHO */
#include <unistd.h>		/* struct termios, tcsetattr(),
				   STDIN_FILENO, TCSAFLUSH,
				   tcgetattr(), ECHO */
#include <signal.h>		/* sig_atomic_t, raise(), struct
				   sigaction, sigemptyset(),
				   sigaction(), sigaddset(), SIGINT,
				   SIGQUIT, SIGHUP, SIGTERM */
#include <stddef.h>		/* NULL, size_t */
#include <sys/types.h>		/* ssize_t */
#include <stdlib.h>		/* EXIT_SUCCESS, EXIT_FAILURE,
				   getopt_long */
#include <stdio.h>		/* fprintf(), stderr, getline(),
				   stdin, feof(), perror(), fputc(),
				   stdout, getopt_long */
#include <errno.h>		/* errno, EINVAL */
#include <iso646.h>		/* or, not */
#include <stdbool.h>		/* bool, false, true */
#include <string.h> 		/* strlen, rindex, strncmp, strcmp */
#include <getopt.h>		/* getopt_long */

volatile bool quit_now = false;
bool debug = false;

void termination_handler(__attribute__((unused))int signum){
  quit_now = true;
}

int main(int argc, char **argv){
  ssize_t ret;
  size_t n;
  struct termios t_new, t_old;
  char *buffer = NULL;
  char *prefix = NULL;
  int status = EXIT_SUCCESS;
  struct sigaction old_action,
    new_action = { .sa_handler = termination_handler,
		   .sa_flags = 0 };

  while (true){
    static struct option long_options[] = {
      {"debug", no_argument, (int *)&debug, 1},
      {"prefix", required_argument, 0, 'p'},
      {0, 0, 0, 0} };

    int option_index = 0;
    ret = getopt_long (argc, argv, "p:", long_options, &option_index);

    if (ret == -1){
      break;
    }
      
    switch(ret){
    case 0:
      break;
    case 'p':
      prefix = optarg;
      break;
    default:
      fprintf(stderr, "bad arguments\n");
      exit(EXIT_FAILURE);
    }
  }
      
  if (debug){
    fprintf(stderr, "Starting %s\n", argv[0]);
  }
  if (debug){
    fprintf(stderr, "Storing current terminal attributes\n");
  }
  
  if (tcgetattr(STDIN_FILENO, &t_old) != 0){
    return EXIT_FAILURE;
  }
  
  sigemptyset(&new_action.sa_mask);
  sigaddset(&new_action.sa_mask, SIGINT);
  sigaddset(&new_action.sa_mask, SIGQUIT);
  sigaddset(&new_action.sa_mask, SIGHUP);
  sigaddset(&new_action.sa_mask, SIGTERM);
  sigaction(SIGINT, NULL, &old_action);
  if (old_action.sa_handler != SIG_IGN)
    sigaction(SIGINT, &new_action, NULL);
  sigaction(SIGQUIT, NULL, &old_action);
  if (old_action.sa_handler != SIG_IGN)
    sigaction(SIGQUIT, &new_action, NULL);
  sigaction(SIGHUP, NULL, &old_action);
  if (old_action.sa_handler != SIG_IGN)
    sigaction(SIGHUP, &new_action, NULL);
  sigaction(SIGTERM, NULL, &old_action);
  if (old_action.sa_handler != SIG_IGN)
    sigaction(SIGTERM, &new_action, NULL);

  
  if (debug){
    fprintf(stderr, "Removing echo flag from terminal attributes\n");
  }
  
  t_new = t_old;
  t_new.c_lflag &= ~ECHO;
  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
    perror("tcsetattr-echo");
    return EXIT_FAILURE;
  }

  if (debug){
    fprintf(stderr, "Waiting for input from stdin \n");
  }
  while(true){
    if (quit_now){
      status = EXIT_FAILURE;
      break;
    }

    if(prefix){
      fprintf(stderr, "%s Password: ", prefix);
    } else {
      fprintf(stderr, "Password: ");
    }      
    ret = getline(&buffer, &n, stdin);
    if (ret > 0){
      fprintf(stdout, "%s", buffer);
      status = EXIT_SUCCESS;
      break;
    }
    // ret == 0 makes no other sence than to retry to read from stdin
    if (ret < 0){
      if (errno != EINTR and not feof(stdin)){
	perror("getline");
	status = EXIT_FAILURE;
	break;
      }
    }
    fputc('\n', stderr);
  }

  if (debug){
    fprintf(stderr, "Restoring terminal attributes\n");
  }
  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
    perror("tcsetattr+echo");
  }

  if (debug){
    fprintf(stderr, "%s is exiting\n", argv[0]);
  }
  
  return status;
}