xref: /netbsd-src/lib/libc/gen/getpass.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: getpass.c,v 1.9 1996/05/20 06:13:07 jtc 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)getpass.c	8.1 (Berkeley) 6/4/93";
39 #else
40 static char rcsid[] = "$NetBSD: getpass.c,v 1.9 1996/05/20 06:13:07 jtc Exp $";
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43 
44 #include <termios.h>
45 #include <signal.h>
46 
47 #include <paths.h>
48 #include <pwd.h>
49 #include <stdio.h>
50 #include <unistd.h>
51 
52 char *
53 getpass(prompt)
54 	const char *prompt;
55 {
56 	struct termios term;
57 	register int ch;
58 	register char *p;
59 	FILE *fp, *outfp;
60 	int echo;
61 	static char buf[_PASSWORD_LEN + 1];
62 	sigset_t oset, nset;
63 
64 	/*
65 	 * read and write to /dev/tty if possible; else read from
66 	 * stdin and write to stderr.
67 	 */
68 	if ((outfp = fp = fopen(_PATH_TTY, "w+")) == NULL) {
69 		outfp = stderr;
70 		fp = stdin;
71 	}
72 
73 	/*
74 	 * note - blocking signals isn't necessarily the
75 	 * right thing, but we leave it for now.
76 	 */
77 	sigemptyset(&nset);
78 	sigaddset(&nset, SIGINT);
79 	sigaddset(&nset, SIGTSTP);
80 	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
81 
82 	(void)tcgetattr(fileno(fp), &term);
83 	if (echo = (term.c_lflag & ECHO)) {
84 		term.c_lflag &= ~ECHO;
85 		(void)tcsetattr(fileno(fp), TCSAFLUSH|TCSASOFT, &term);
86 	}
87 	(void)fputs(prompt, outfp);
88 	rewind(outfp);			/* implied flush */
89 	for (p = buf; (ch = getc(fp)) != EOF && ch != '\n';)
90 		if (p < buf + _PASSWORD_LEN)
91 			*p++ = ch;
92 	*p = '\0';
93 	(void)write(fileno(outfp), "\n", 1);
94 	if (echo) {
95 		term.c_lflag |= ECHO;
96 		(void)tcsetattr(fileno(fp), TCSAFLUSH|TCSASOFT, &term);
97 	}
98 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
99 	if (fp != stdin)
100 		(void)fclose(fp);
101 	return(buf);
102 }
103