xref: /netbsd-src/lib/libc/gen/getpass.c (revision 9c20f740a382714c03e8c923a5ebf52f5279aa84)
1 /*
2  * Copyright (c) 1988 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 /*static char *sccsid = "from: @(#)getpass.c	5.9 (Berkeley) 5/6/91";*/
36 static char *rcsid = "$Id: getpass.c,v 1.3 1993/08/26 00:44:41 jtc Exp $";
37 #endif /* LIBC_SCCS and not lint */
38 
39 #include <sys/termios.h>
40 #include <sys/signal.h>
41 #include <stdio.h>
42 #include <unistd.h>
43 #include <pwd.h>
44 
45 char *
46 getpass(prompt)
47 	const char *prompt;
48 {
49 	struct termios term;
50 	register int ch;
51 	register char *p;
52 	FILE *fp, *outfp;
53 	long omask;
54 	int echo;
55 	static char buf[_PASSWORD_LEN + 1];
56 
57 	/*
58 	 * read and write to /dev/tty if possible; else read from
59 	 * stdin and write to stderr.
60 	 */
61 	if ((outfp = fp = fopen("/dev/tty", "w+")) == NULL) {
62 		outfp = stderr;
63 		fp = stdin;
64 	}
65 	/*
66 	 * note - blocking signals isn't necessarily the
67 	 * right thing, but we leave it for now.
68 	 */
69 	omask = sigblock(sigmask(SIGINT)|sigmask(SIGTSTP));
70 	(void)tcgetattr(fileno(fp), &term);
71 	if (echo = (term.c_lflag & ECHO)) {
72 		term.c_lflag &= ~ECHO;
73 		(void)tcsetattr(fileno(fp), TCSAFLUSH|TCSASOFT, &term);
74 	}
75 	(void)fputs(prompt, outfp);
76 	rewind(outfp);			/* implied flush */
77 	for (p = buf; (ch = getc(fp)) != EOF && ch != '\n';)
78 		if (p < buf + _PASSWORD_LEN)
79 			*p++ = ch;
80 	*p = '\0';
81 	(void)write(fileno(outfp), "\n", 1);
82 	if (echo) {
83 		term.c_lflag |= ECHO;
84 		tcsetattr(fileno(fp), TCSAFLUSH|TCSASOFT, &term);
85 	}
86 	(void)sigsetmask(omask);
87 	if (fp != stdin)
88 		(void)fclose(fp);
89 	return(buf);
90 }
91