1/*	$NetBSD: getpass.c,v 1.15 2003/08/07 16:42:50 agc Exp $	*/
2
3/*
4 * Copyright (c) 1988, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34#if 0
35static char sccsid[] = "@(#)getpass.c	8.1 (Berkeley) 6/4/93";
36#else
37__RCSID("$NetBSD: getpass.c,v 1.15 2003/08/07 16:42:50 agc Exp $");
38#endif
39#endif /* LIBC_SCCS and not lint */
40
41#include "namespace.h"
42
43#include <assert.h>
44#include <paths.h>
45#include <pwd.h>
46#include <signal.h>
47#include <stdio.h>
48#include <termios.h>
49#include <unistd.h>
50
51#ifdef __weak_alias
52__weak_alias(getpass,_getpass)
53#endif
54
55char *
56getpass(prompt)
57	const char *prompt;
58{
59	struct termios term;
60	int ch;
61	char *p;
62	FILE *fp, *outfp;
63	int echo;
64	static char buf[_PASSWORD_LEN + 1];
65	sigset_t oset, nset;
66
67	_DIAGASSERT(prompt != NULL);
68
69	/*
70	 * note - blocking signals isn't necessarily the
71	 * right thing, but we leave it for now.
72	 */
73	sigemptyset(&nset);
74	sigaddset(&nset, SIGINT);
75	sigaddset(&nset, SIGTSTP);
76	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
77
78	/*
79	 * read and write to /dev/tty if possible; else read from
80	 * stdin and write to stderr.
81	 */
82	if ((outfp = fp = fopen(_PATH_TTY, "w+")) == NULL) {
83		outfp = stderr;
84		fp = stdin;
85	}
86	(void)tcgetattr(fileno(fp), &term);
87	if ((echo = (term.c_lflag & ECHO)) != 0) {
88		term.c_lflag &= ~ECHO;
89		(void)tcsetattr(fileno(fp), TCSAFLUSH|TCSASOFT, &term);
90	}
91	if (prompt != NULL)
92		(void)fputs(prompt, outfp);
93	rewind(outfp);			/* implied flush */
94	for (p = buf; (ch = getc(fp)) != EOF && ch != '\n';)
95		if (p < buf + _PASSWORD_LEN)
96			*p++ = ch;
97	*p = '\0';
98	(void)write(fileno(outfp), "\n", 1);
99	if (echo) {
100		term.c_lflag |= ECHO;
101		(void)tcsetattr(fileno(fp), TCSAFLUSH|TCSASOFT, &term);
102	}
103	if (fp != stdin)
104		(void)fclose(fp);
105	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
106	return(buf);
107}
108