summaryrefslogtreecommitdiff
path: root/usr.bin/sudo/tgetpass.c
blob: d8d2080d9ee5831f38b268dfcd02e4f621dbdabd (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
/*
 * Copyright (c) 1996, 1998-2000 Todd C. Miller <Todd.Miller@courtesan.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 4. Products derived from this software may not be called "Sudo" nor
 *    may "Sudo" appear in their names without specific prior written
 *    permission from the author.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"

#include <stdio.h>
#ifdef STDC_HEADERS
#include <stdlib.h>
#endif /* STDC_HEADERS */
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif /* HAVE_UNISTD_H */
#ifdef HAVE_STRING_H
#include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <pwd.h>
#include <sys/param.h>
#include <sys/types.h>
#ifdef HAVE_SYS_BSDTYPES_H
#include <sys/bsdtypes.h>
#endif /* HAVE_SYS_BSDTYPES_H */
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif /* HAVE_SYS_SELECT_H */
#include <sys/time.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
static const char rcsid[] = "$Sudo: tgetpass.c,v 1.95 2000/02/27 03:48:56 millert Exp $";
#endif /* lint */

#ifndef TCSASOFT
#define TCSASOFT	0
#endif /* TCSASOFT */

/*
 * Abstract method of getting at the term flags.
 */
#undef TERM
#undef tflags
#ifdef HAVE_TERMIOS_H
# define TERM			termios
# define tflags			c_lflag
# define term_getattr(f, t)	tcgetattr(f, t)
# define term_setattr(f, t)	tcsetattr(f, TCSAFLUSH|TCSASOFT, t)
#else
# ifdef HAVE_TERMIO_H
# define TERM			termio
# define tflags			c_lflag
# define term_getattr(f, t)	ioctl(f, TCGETA, t)
# define term_setattr(f, t)	ioctl(f, TCSETA, t)
# else
#  define TERM			sgttyb
#  define tflags		sg_flags
#  define term_getattr(f, t)	ioctl(f, TIOCGETP, t)
#  define term_setattr(f, t)	ioctl(f, TIOCSETP, t)
# endif /* HAVE_TERMIO_H */
#endif /* HAVE_TERMIOS_H */

static char *tgetline __P((int, char *, size_t, int));

/*
 * Like getpass(3) but with timeout and echo flags.
 */
char *
tgetpass(prompt, timeout, flags)
    const char *prompt;
    int timeout;
    int flags;
{
    struct TERM term, oterm;
    int input, output;
    static char buf[SUDO_PASS_MAX + 1];

    /* Open /dev/tty for reading/writing if possible else use stdin/stderr. */
    if ((flags & TGP_STDIN) ||
	(input = output = open(_PATH_TTY, O_RDWR|O_NOCTTY)) == -1) {
	input = STDIN_FILENO;
	output = STDERR_FILENO;
    }

    if (prompt)
	(void) write(output, prompt, strlen(prompt) + 1);

    /* Turn echo off/on as specified by flags.  */
    (void) term_getattr(input, &oterm);
    (void) memcpy(&term, &oterm, sizeof(term));
    if ((flags & TGP_ECHO) && !(term.tflags & ECHO))
	term.tflags |= ECHO;
    else if (!(flags & TGP_ECHO) && (term.tflags & ECHO))
	term.tflags &= ~ECHO;
    (void) term_setattr(input, &term);

    buf[0] = '\0';
    tgetline(input, buf, sizeof(buf), timeout);

    /* Restore old tty flags.  */
    (void) term_setattr(input, &oterm);

    if (!(flags & TGP_ECHO))
	(void) write(output, "\n", 1);

    if (input != STDIN_FILENO)
	(void) close(input);

    return(buf);
}

/*
 * Get a line of input (optionally timing out) and place it in buf.
 */
static char *
tgetline(fd, buf, bufsiz, timeout)
    int fd;
    char *buf;
    size_t bufsiz;
    int timeout;
{
    size_t left;
    int n;
    fd_set *readfds = NULL;
    struct timeval tv;
    char c;
    char *cp;

    if (bufsiz == 0)
	return(NULL);			/* sanity */

    cp = buf;
    left = bufsiz;

    /*
     * Timeout of <= 0 means no timeout.
     */
    if (timeout > 0) {
	/* Setup for select(2) */
	n = howmany(fd + 1, NFDBITS) * sizeof(fd_mask);
	readfds = (fd_set *) emalloc(n);
	(void) memset((VOID *)readfds, 0, n);

	/* Set timeout for select */
	tv.tv_sec = timeout;
	tv.tv_usec = 0;

	while (--left) {
	    FD_SET(fd, readfds);

	    /* Make sure there is something to read (or timeout) */
	    while ((n = select(fd + 1, readfds, 0, 0, &tv)) == -1 &&
		errno == EINTR)
		;
	    if (n == 0)
		return(NULL);		/* timeout */

	    /* Read a character, exit loop on error, EOF or EOL */
	    n = read(fd, &c, 1);
	    if (n != 1 || c == '\n' || c == '\r')
		break;
	    *cp++ = c;
	}
	free(readfds);
    } else {
	/* Keep reading until out of space, EOF, error, or newline */
	while (--left && (n = read(fd, &c, 1)) == 1 && c != '\n' && c != '\r')
	    *cp++ = c;
    }
    *cp = '\0';

    return(cp == buf ? NULL : buf);
}