1/*	$OpenBSD: readpassphrase.c,v 1.22 2010/01/13 10:20:54 dtucker Exp $	*/
2
3/*
4 * Copyright (c) 2000-2002, 2007 Todd C. Miller <Todd.Miller@courtesan.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 *
18 * Sponsored in part by the Defense Advanced Research Projects
19 * Agency (DARPA) and Air Force Research Laboratory, Air Force
20 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
21 */
22
23/* OPENBSD ORIGINAL: lib/libc/gen/readpassphrase.c */
24
25#include "includes.h"
26
27#ifndef HAVE_READPASSPHRASE
28
29#include <termios.h>
30#include <signal.h>
31#include <ctype.h>
32#include <fcntl.h>
33#include <readpassphrase.h>
34#include <errno.h>
35#include <string.h>
36#include <unistd.h>
37
38#ifdef TCSASOFT
39# define _T_FLUSH	(TCSAFLUSH|TCSASOFT)
40#else
41# define _T_FLUSH	(TCSAFLUSH)
42#endif
43
44/* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
45#if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
46#  define _POSIX_VDISABLE       VDISABLE
47#endif
48
49static volatile sig_atomic_t signo[_NSIG];
50
51static void handler(int);
52
53char *
54readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
55{
56	ssize_t nr;
57	int input, output, save_errno, i, need_restart;
58	char ch, *p, *end;
59	struct termios term, oterm;
60	struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
61	struct sigaction savetstp, savettin, savettou, savepipe;
62
63	/* I suppose we could alloc on demand in this case (XXX). */
64	if (bufsiz == 0) {
65		errno = EINVAL;
66		return(NULL);
67	}
68
69restart:
70	for (i = 0; i < _NSIG; i++)
71		signo[i] = 0;
72	nr = -1;
73	save_errno = 0;
74	need_restart = 0;
75	/*
76	 * Read and write to /dev/tty if available.  If not, read from
77	 * stdin and write to stderr unless a tty is required.
78	 */
79	if ((flags & RPP_STDIN) ||
80	    (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
81		if (flags & RPP_REQUIRE_TTY) {
82			errno = ENOTTY;
83			return(NULL);
84		}
85		input = STDIN_FILENO;
86		output = STDERR_FILENO;
87	}
88
89	/*
90	 * Catch signals that would otherwise cause the user to end
91	 * up with echo turned off in the shell.  Don't worry about
92	 * things like SIGXCPU and SIGVTALRM for now.
93	 */
94	sigemptyset(&sa.sa_mask);
95	sa.sa_flags = 0;		/* don't restart system calls */
96	sa.sa_handler = handler;
97	(void)sigaction(SIGALRM, &sa, &savealrm);
98	(void)sigaction(SIGHUP, &sa, &savehup);
99	(void)sigaction(SIGINT, &sa, &saveint);
100	(void)sigaction(SIGPIPE, &sa, &savepipe);
101	(void)sigaction(SIGQUIT, &sa, &savequit);
102	(void)sigaction(SIGTERM, &sa, &saveterm);
103	(void)sigaction(SIGTSTP, &sa, &savetstp);
104	(void)sigaction(SIGTTIN, &sa, &savettin);
105	(void)sigaction(SIGTTOU, &sa, &savettou);
106
107	/* Turn off echo if possible. */
108	if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
109		memcpy(&term, &oterm, sizeof(term));
110		if (!(flags & RPP_ECHO_ON))
111			term.c_lflag &= ~(ECHO | ECHONL);
112#ifdef VSTATUS
113		if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
114			term.c_cc[VSTATUS] = _POSIX_VDISABLE;
115#endif
116		(void)tcsetattr(input, _T_FLUSH, &term);
117	} else {
118		memset(&term, 0, sizeof(term));
119		term.c_lflag |= ECHO;
120		memset(&oterm, 0, sizeof(oterm));
121		oterm.c_lflag |= ECHO;
122	}
123
124	/* No I/O if we are already backgrounded. */
125	if (signo[SIGTTOU] != 1 && signo[SIGTTIN] != 1) {
126		if (!(flags & RPP_STDIN))
127			(void)write(output, prompt, strlen(prompt));
128		end = buf + bufsiz - 1;
129		p = buf;
130		while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
131			if (p < end) {
132				if ((flags & RPP_SEVENBIT))
133					ch &= 0x7f;
134				if (isalpha(ch)) {
135					if ((flags & RPP_FORCELOWER))
136						ch = (char)tolower(ch);
137					if ((flags & RPP_FORCEUPPER))
138						ch = (char)toupper(ch);
139				}
140				*p++ = ch;
141			}
142		}
143		*p = '\0';
144		save_errno = errno;
145		if (!(term.c_lflag & ECHO))
146			(void)write(output, "\n", 1);
147	}
148
149	/* Restore old terminal settings and signals. */
150	if (memcmp(&term, &oterm, sizeof(term)) != 0) {
151		while (tcsetattr(input, _T_FLUSH, &oterm) == -1 &&
152		    errno == EINTR)
153			continue;
154	}
155	(void)sigaction(SIGALRM, &savealrm, NULL);
156	(void)sigaction(SIGHUP, &savehup, NULL);
157	(void)sigaction(SIGINT, &saveint, NULL);
158	(void)sigaction(SIGQUIT, &savequit, NULL);
159	(void)sigaction(SIGPIPE, &savepipe, NULL);
160	(void)sigaction(SIGTERM, &saveterm, NULL);
161	(void)sigaction(SIGTSTP, &savetstp, NULL);
162	(void)sigaction(SIGTTIN, &savettin, NULL);
163	(void)sigaction(SIGTTOU, &savettou, NULL);
164	if (input != STDIN_FILENO)
165		(void)close(input);
166
167	/*
168	 * If we were interrupted by a signal, resend it to ourselves
169	 * now that we have restored the signal handlers.
170	 */
171	for (i = 0; i < _NSIG; i++) {
172		if (signo[i]) {
173			kill(getpid(), i);
174			switch (i) {
175			case SIGTSTP:
176			case SIGTTIN:
177			case SIGTTOU:
178				need_restart = 1;
179			}
180		}
181	}
182	if (need_restart)
183		goto restart;
184
185	if (save_errno)
186		errno = save_errno;
187	return(nr == -1 ? NULL : buf);
188}
189
190#if 0
191char *
192getpass(const char *prompt)
193{
194	static char buf[_PASSWORD_LEN + 1];
195
196	return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
197}
198#endif
199
200static void handler(int s)
201{
202
203	signo[s] = 1;
204}
205#endif /* HAVE_READPASSPHRASE */
206