readpassphrase.c revision 1.2 
1/*	$NetBSD: readpassphrase.c,v 1.2 2012/04/13 23:57:08 christos Exp $	*/
2/*
3 * Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
19 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
20 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
21 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
25 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
26 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include "includes.h"
30#if defined(LIBC_SCCS) && !defined(lint)
31static const char rcsid[] = "$OpenBSD: readpassphrase.c,v 1.7 2001/08/07 19:34:11 millert Exp $";
32#endif /* LIBC_SCCS and not lint */
33
34#include <ctype.h>
35#include <errno.h>
36#include <fcntl.h>
37#include <paths.h>
38#include <pwd.h>
39#include <signal.h>
40#include <string.h>
41#include <termios.h>
42#include <unistd.h>
43#include <readpassphrase.h>
44
45char *
46readpassphrase(
47	const char *prompt,
48	char *buf,
49	size_t bufsiz,
50	int flags)
51{
52	int input, output;
53	char *ret;
54
55	/* I suppose we could alloc on demand in this case (XXX). */
56	if (bufsiz == 0) {
57		errno = EINVAL;
58		return(NULL);
59	}
60
61	/*
62	 * Read and write to /dev/tty if available.  If not, read from
63	 * stdin and write to stderr unless a tty is required.
64	 */
65	if ((input = output = open(_PATH_TTY, O_RDWR)) == -1) {
66		if (flags & RPP_REQUIRE_TTY) {
67			errno = ENOTTY;
68			return(NULL);
69		}
70		input = STDIN_FILENO;
71		output = STDERR_FILENO;
72	}
73
74#ifndef GETPASS_ECHO
75	struct termios term, oterm;
76	char ch, *p, *end;
77	sigset_t oset, nset;
78
79	/*
80	 * We block SIGINT and SIGTSTP so the terminal is not left
81	 * in an inconsistent state (ie: no echo).  It would probably
82	 * be better to simply catch these though.
83	 */
84	sigemptyset(&nset);
85	sigaddset(&nset, SIGINT);
86	sigaddset(&nset, SIGTSTP);
87	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
88
89	/* Turn off echo if possible. */
90	if (tcgetattr(input, &oterm) == 0) {
91		memcpy(&term, &oterm, sizeof(term));
92		if (!(flags & RPP_ECHO_ON) && (term.c_lflag & ECHO))
93			term.c_lflag &= ~ECHO;
94		if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
95			term.c_cc[VSTATUS] = _POSIX_VDISABLE;
96		(void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
97	} else {
98		memset(&term, 0, sizeof(term));
99		memset(&oterm, 0, sizeof(oterm));
100	}
101
102	(void)write(output, prompt, strlen(prompt));
103	end = buf + bufsiz - 1;
104	for (p = buf; read(input, &ch, 1) == 1 && ch != '\n' && ch != '\r';) {
105		if (p < end) {
106			if ((flags & RPP_SEVENBIT))
107				ch &= 0x7f;
108			if (isalpha((unsigned char)ch)) {
109				if ((flags & RPP_FORCELOWER))
110					ch = tolower((unsigned char)ch);
111				if ((flags & RPP_FORCEUPPER))
112					ch = toupper((unsigned char)ch);
113			}
114			*p++ = ch;
115		}
116	}
117	*p = '\0';
118	if (!(term.c_lflag & ECHO))
119		(void)write(output, "\n", 1);
120
121	/* Restore old terminal settings and signal mask. */
122	if (memcmp(&term, &oterm, sizeof(term)) != 0)
123		(void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm);
124	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
125	ret = buf;
126#else
127	int gflags = 0;
128	int fd[3];
129
130	if (flags & RPP_ECHO_ON)
131		gflags |= GETPASS_ECHO;
132	if (flags & RPP_REQUIRE_TTY)
133		gflags |= GETPASS_NEED_TTY;
134	if (flags & RPP_FORCELOWER)
135		gflags |= GETPASS_FORCE_LOWER;
136	if (flags & RPP_FORCEUPPER)
137		gflags |= GETPASS_FORCE_UPPER;
138	if (flags & RPP_SEVENBIT)
139		gflags |= GETPASS_7BIT;
140
141	fd[0] = input;
142	fd[1] = fd[2] = output;
143	ret = getpassfd(prompt, buf, bufsiz, fd, gflags, 0);
144	if ((gflags & GETPASS_ECHO) == 0)
145		(void)write(output, "\n", 1);
146
147#endif
148	if (input != STDIN_FILENO)
149		(void)close(input);
150
151	return ret;
152}
153
154char *
155getpass(prompt)
156        const char *prompt;
157{
158	static char buf[_PASSWORD_LEN + 1];
159
160	return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
161}
162