1/*	$OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $	*/
2
3/*
4 * Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com>
5 * 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. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
21 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static const char rcsid[] = "$OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $";
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: src/lib/libc/gen/readpassphrase.c,v 1.6 2002/03/09 03:16:41 green Exp $");
35
36#include "xlocale_private.h"
37
38#include "namespace.h"
39#include <ctype.h>
40#include <errno.h>
41#include <fcntl.h>
42#include <paths.h>
43#include <pwd.h>
44#include <signal.h>
45#include <string.h>
46#include <termios.h>
47#include <unistd.h>
48#include <readpassphrase.h>
49#include "un-namespace.h"
50
51static volatile sig_atomic_t signo;
52
53static void handler(int);
54
55char *
56readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
57{
58	ssize_t nr;
59	int input, output, save_errno;
60	char ch, *p, *end;
61	struct termios term, oterm;
62	struct sigaction sa, saveint, savehup, savequit, saveterm;
63	struct sigaction savetstp, savettin, savettou;
64	locale_t loc = __current_locale();
65
66	/* I suppose we could alloc on demand in this case (XXX). */
67	if (bufsiz == 0) {
68		errno = EINVAL;
69		return(NULL);
70	}
71
72restart:
73	/*
74	 * Read and write to /dev/tty if available.  If not, read from
75	 * stdin and write to stderr unless a tty is required.
76	 */
77	if ((input = output = _open(_PATH_TTY, O_RDWR)) == -1) {
78		if (flags & RPP_REQUIRE_TTY) {
79			errno = ENOTTY;
80			return(NULL);
81		}
82		input = STDIN_FILENO;
83		output = STDERR_FILENO;
84	}
85
86	/*
87	 * Catch signals that would otherwise cause the user to end
88	 * up with echo turned off in the shell.  Don't worry about
89	 * things like SIGALRM and SIGPIPE for now.
90	 */
91	sigemptyset(&sa.sa_mask);
92	sa.sa_flags = 0;		/* don't restart system calls */
93	sa.sa_handler = handler;
94	(void)_sigaction(SIGINT, &sa, &saveint);
95	(void)_sigaction(SIGHUP, &sa, &savehup);
96	(void)_sigaction(SIGQUIT, &sa, &savequit);
97	(void)_sigaction(SIGTERM, &sa, &saveterm);
98	(void)_sigaction(SIGTSTP, &sa, &savetstp);
99	(void)_sigaction(SIGTTIN, &sa, &savettin);
100	(void)_sigaction(SIGTTOU, &sa, &savettou);
101
102	/* Turn off echo if possible. */
103	if (tcgetattr(input, &oterm) == 0) {
104		memcpy(&term, &oterm, sizeof(term));
105		if (!(flags & RPP_ECHO_ON))
106			term.c_lflag &= ~(ECHO | ECHONL);
107		if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
108			term.c_cc[VSTATUS] = _POSIX_VDISABLE;
109		(void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
110	} else {
111		memset(&term, 0, sizeof(term));
112		memset(&oterm, 0, sizeof(oterm));
113	}
114
115	(void)_write(output, prompt, strlen(prompt));
116	end = buf + bufsiz - 1;
117	for (p = buf; (nr = _read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) {
118		if (p < end) {
119			if ((flags & RPP_SEVENBIT))
120				ch &= 0x7f;
121			if (isalpha_l(ch, loc)) {
122				if ((flags & RPP_FORCELOWER))
123					ch = tolower_l(ch, loc);
124				if ((flags & RPP_FORCEUPPER))
125					ch = toupper_l(ch, loc);
126			}
127			*p++ = ch;
128		}
129	}
130	*p = '\0';
131	save_errno = errno;
132	if (!(term.c_lflag & ECHO))
133		(void)_write(output, "\n", 1);
134
135	/* Restore old terminal settings and signals. */
136	if (memcmp(&term, &oterm, sizeof(term)) != 0)
137		(void)tcsetattr(input, TCSANOW|TCSASOFT, &oterm);
138	(void)_sigaction(SIGINT, &saveint, NULL);
139	(void)_sigaction(SIGHUP, &savehup, NULL);
140	(void)_sigaction(SIGQUIT, &savequit, NULL);
141	(void)_sigaction(SIGTERM, &saveterm, NULL);
142	(void)_sigaction(SIGTSTP, &savetstp, NULL);
143	(void)_sigaction(SIGTTIN, &savettin, NULL);
144	(void)_sigaction(SIGTTOU, &savettou, NULL);
145	if (input != STDIN_FILENO)
146		(void)_close(input);
147
148	/*
149	 * If we were interrupted by a signal, resend it to ourselves
150	 * now that we have restored the signal handlers.
151	 */
152	if (signo) {
153		kill(getpid(), signo);
154		switch (signo) {
155		case SIGTSTP:
156		case SIGTTIN:
157		case SIGTTOU:
158			signo = 0;
159			goto restart;
160		}
161	}
162
163	errno = save_errno;
164	return(nr == -1 ? NULL : buf);
165}
166
167char *
168getpass(const char *prompt)
169{
170	const size_t bufsiz = _PASSWORD_LEN + 1;
171	static char *buf = NULL;
172
173	if (buf == NULL) {
174		buf = malloc(bufsiz);
175		if (buf == NULL) {
176			return NULL;
177		}
178	}
179
180	if (readpassphrase(prompt, buf, bufsiz, RPP_ECHO_OFF) == NULL) {
181		buf[0] = '\0';
182	}
183	return buf;
184}
185
186static void handler(int s)
187{
188
189	signo = s;
190}
191