summaryrefslogtreecommitdiff
path: root/usr.bin/sudo/tgetpass.c
blob: 2c94cdb11a26083cbaae183f56de0d823c4cfbaf (plain)
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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
/*
 * Copyright (c) 1996, 1998-2005 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */

#ifdef __TANDEM
# include <floss.h>
#endif

#include <config.h>

#include <sys/types.h>
#include <sys/param.h>
#ifdef HAVE_SYS_BSDTYPES_H
# include <sys/bsdtypes.h>
#endif /* HAVE_SYS_BSDTYPES_H */
#include <sys/time.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
#  include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# if defined(HAVE_MEMORY_H) && !defined(STDC_HEADERS)
#  include <memory.h>
# endif
# include <string.h>
#else
# ifdef HAVE_STRINGS_H
#  include <strings.h>
# endif
#endif /* HAVE_STRING_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#include <pwd.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#ifdef HAVE_TERMIOS_H
# include <termios.h>
#else
# ifdef HAVE_TERMIO_H
#  include <termio.h>
# else
#  include <sgtty.h>
#  include <sys/ioctl.h>
# endif /* HAVE_TERMIO_H */
#endif /* HAVE_TERMIOS_H */

#include "sudo.h"

#ifndef lint
__unused static const char rcsid[] = "$Sudo: tgetpass.c,v 1.111.2.7 2008/06/21 00:27:01 millert Exp $";
#endif /* lint */

#ifndef TCSASOFT
# define TCSASOFT	0
#endif
#ifndef ECHONL
# define ECHONL	0
#endif

#ifndef _POSIX_VDISABLE
# ifdef VDISABLE
#  define _POSIX_VDISABLE	VDISABLE
# else
#  define _POSIX_VDISABLE	0
# endif
#endif

/*
 * Compat macros for non-termios systems.
 */
#ifndef HAVE_TERMIOS_H
# ifdef HAVE_TERMIO_H
#  undef termios
#  define termios		termio
#  define tcgetattr(f, t)	ioctl(f, TCGETA, t)
#  define tcsetattr(f, a, t)	ioctl(f, a, t)
#  undef TCSAFLUSH
#  define TCSAFLUSH		TCSETAF
# else
#  undef termios
#  define termios		sgttyb
#  define c_lflag		sg_flags
#  define tcgetattr(f, t)	ioctl(f, TIOCGETP, t)
#  define tcsetattr(f, a, t)	ioctl(f, a, t)
#  undef TCSAFLUSH
#  define TCSAFLUSH		TIOCSETP
# endif /* HAVE_TERMIO_H */
#endif /* HAVE_TERMIOS_H */

static volatile sig_atomic_t signo;

static void handler __P((int));
static char *getln __P((int, char *, size_t));

/*
 * Like getpass(3) but with timeout and echo flags.
 */
char *
tgetpass(prompt, timeout, flags)
    const char *prompt;
    int timeout;
    int flags;
{
    sigaction_t sa, savealrm, saveint, savehup, savequit, saveterm;
    sigaction_t savetstp, savettin, savettou;
    struct termios term, oterm;
    char *pass;
    static char buf[SUDO_PASS_MAX + 1];
    int input, output, save_errno;

    (void) fflush(stdout);
restart:
    signo = 0;
    pass = NULL;
    save_errno = 0;
    /* Open /dev/tty for reading/writing if possible else use stdin/stderr. */
    if (ISSET(flags, TGP_STDIN) ||
	(input = output = open(_PATH_TTY, O_RDWR|O_NOCTTY)) == -1) {
	input = STDIN_FILENO;
	output = STDERR_FILENO;
    }

    /*
     * Catch signals that would otherwise cause the user to end
     * up with echo turned off in the shell.
     */
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = SA_INTERRUPT;	/* don't restart system calls */
    sa.sa_handler = handler;
    (void) sigaction(SIGALRM, &sa, &savealrm);
    (void) sigaction(SIGINT, &sa, &saveint);
    (void) sigaction(SIGHUP, &sa, &savehup);
    (void) sigaction(SIGQUIT, &sa, &savequit);
    (void) sigaction(SIGTERM, &sa, &saveterm);
    (void) sigaction(SIGTSTP, &sa, &savetstp);
    (void) sigaction(SIGTTIN, &sa, &savettin);
    (void) sigaction(SIGTTOU, &sa, &savettou);

    /* Turn echo off/on as specified by flags.  */
    if (tcgetattr(input, &oterm) == 0) {
	(void) memcpy(&term, &oterm, sizeof(term));
	if (!ISSET(flags, TGP_ECHO))
	    CLR(term.c_lflag, ECHO|ECHONL);
#ifdef VSTATUS
	term.c_cc[VSTATUS] = _POSIX_VDISABLE;
#endif
	(void) tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
    } else {
	memset(&term, 0, sizeof(term));
	memset(&oterm, 0, sizeof(oterm));
    }

    /* No output if we are already backgrounded. */
    if (signo != SIGTTOU && signo != SIGTTIN) {
	if (prompt)
	    (void) write(output, prompt, strlen(prompt));

	if (timeout > 0)
	    alarm(timeout);
	pass = getln(input, buf, sizeof(buf));
	alarm(0);
	save_errno = errno;

	if (!ISSET(term.c_lflag, ECHO))
	    (void) write(output, "\n", 1);
    }

    /* Restore old tty settings and signals. */
    if (memcmp(&term, &oterm, sizeof(term)) != 0) {
	while (tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm) == -1 &&
	    errno == EINTR)
	    continue;
    }
    (void) sigaction(SIGALRM, &savealrm, NULL);
    (void) sigaction(SIGINT, &saveint, NULL);
    (void) sigaction(SIGHUP, &savehup, NULL);
    (void) sigaction(SIGQUIT, &savequit, NULL);
    (void) sigaction(SIGTERM, &saveterm, NULL);
    (void) sigaction(SIGTSTP, &savetstp, NULL);
    (void) sigaction(SIGTTIN, &savettin, NULL);
    (void) sigaction(SIGTTOU, &savettou, NULL);
    if (input != STDIN_FILENO)
	(void) close(input);

    /*
     * If we were interrupted by a signal, resend it to ourselves
     * now that we have restored the signal handlers.
     */
    if (signo) {
	kill(getpid(), signo);
	switch (signo) {
	    case SIGTSTP:
	    case SIGTTIN:
	    case SIGTTOU:
		goto restart;
	}
    }

    if (save_errno)
	errno = save_errno;
    return(pass);
}

static char *
getln(fd, buf, bufsiz)
    int fd;
    char *buf;
    size_t bufsiz;
{
    char c, *cp;
    ssize_t nr;

    if (bufsiz == 0) {
	errno = EINVAL;
	return(NULL);			/* sanity */
    }

    cp = buf;
    nr = -1;
    while (--bufsiz && (nr = read(fd, &c, 1)) == 1 && c != '\n' && c != '\r')
	*cp++ = c;
    *cp = '\0';
    return(nr == -1 ? NULL : buf);
}

static void
handler(s)
    int s;
{
    if (s != SIGALRM)
	signo = s;
}