[openssh.git] / openbsd-compat / readpassphrase.c

/*	$OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $	*/

/*
 * Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "$OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $";
#endif /* LIBC_SCCS and not lint */

#include "includes.h"

#ifndef HAVE_READPASSPHRASE

#include <termios.h>
#include <readpassphrase.h>

#ifdef TCSASOFT
# define _T_FLUSH	(TCSAFLUSH|TCSASOFT)
#else
# define _T_FLUSH	(TCSAFLUSH)
#endif

/* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
#if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
#  define _POSIX_VDISABLE       VDISABLE
#endif

static volatile sig_atomic_t signo;

static void handler(int);

char *
readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
{
	ssize_t nr;
	int input, output, save_errno;
	char ch, *p, *end;
	struct termios term, oterm;
	struct sigaction sa, saveint, savehup, savequit, saveterm;
	struct sigaction savetstp, savettin, savettou;

	/* I suppose we could alloc on demand in this case (XXX). */
	if (bufsiz == 0) {
		errno = EINVAL;
		return(NULL);
	}

restart:
	/*
	 * Read and write to /dev/tty if available.  If not, read from
	 * stdin and write to stderr unless a tty is required.
	 */
	if ((input = output = open(_PATH_TTY, O_RDWR)) == -1) {
		if (flags & RPP_REQUIRE_TTY) {
			errno = ENOTTY;
			return(NULL);
		}
		input = STDIN_FILENO;
		output = STDERR_FILENO;
	}

	/*
	 * Catch signals that would otherwise cause the user to end
	 * up with echo turned off in the shell.  Don't worry about
	 * things like SIGALRM and SIGPIPE for now.
	 */
	sigemptyset(&sa.sa_mask);
	sa.sa_flags = 0;		/* don't restart system calls */
	sa.sa_handler = handler;
	(void)sigaction(SIGINT, &sa, &saveint);
	(void)sigaction(SIGHUP, &sa, &savehup);
	(void)sigaction(SIGQUIT, &sa, &savequit);
	(void)sigaction(SIGTERM, &sa, &saveterm);
	(void)sigaction(SIGTSTP, &sa, &savetstp);
	(void)sigaction(SIGTTIN, &sa, &savettin);
	(void)sigaction(SIGTTOU, &sa, &savettou);

	/* Turn off echo if possible. */
	if (tcgetattr(input, &oterm) == 0) {
		memcpy(&term, &oterm, sizeof(term));
		if (!(flags & RPP_ECHO_ON))
			term.c_lflag &= ~(ECHO | ECHONL);
#ifdef VSTATUS
		if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
			term.c_cc[VSTATUS] = _POSIX_VDISABLE;
#endif
		(void)tcsetattr(input, _T_FLUSH, &term);
	} else {
		memset(&term, 0, sizeof(term));
		memset(&oterm, 0, sizeof(oterm));
	}

	(void)write(output, prompt, strlen(prompt));
	end = buf + bufsiz - 1;
	for (p = buf; (nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) {
		if (p < end) {
			if ((flags & RPP_SEVENBIT))
				ch &= 0x7f;
			if (isalpha(ch)) {
				if ((flags & RPP_FORCELOWER))
					ch = tolower(ch);
				if ((flags & RPP_FORCEUPPER))
					ch = toupper(ch);
			}
			*p++ = ch;
		}
	}
	*p = '\0';
	save_errno = errno;
	if (!(term.c_lflag & ECHO))
		(void)write(output, "\n", 1);

	/* Restore old terminal settings and signals. */
	if (memcmp(&term, &oterm, sizeof(term)) != 0)
		(void)tcsetattr(input, _T_FLUSH, &oterm);
	(void)sigaction(SIGINT, &saveint, NULL);
	(void)sigaction(SIGHUP, &savehup, NULL);
	(void)sigaction(SIGQUIT, &savequit, NULL);
	(void)sigaction(SIGTERM, &saveterm, NULL);
	(void)sigaction(SIGTSTP, &savetstp, NULL);
	(void)sigaction(SIGTTIN, &savettin, NULL);
	(void)sigaction(SIGTTOU, &savettou, NULL);
	if (input != STDIN_FILENO)
		(void)close(input);

	/*
	 * If we were interrupted by a signal, resend it to ourselves
	 * now that we have restored the signal handlers.
	 */
	if (signo) {
		kill(getpid(), signo); 
		switch (signo) {
		case SIGTSTP:
		case SIGTTIN:
		case SIGTTOU:
			signo = 0;
			goto restart;
		}
	}

	errno = save_errno;
	return(nr == -1 ? NULL : buf);
}
  
#if 0
char *
getpass(const char *prompt)
{
	static char buf[_PASSWORD_LEN + 1];

	return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
}
#endif

static void handler(int s)
{
	signo = s;
}
#endif /* HAVE_READPASSPHRASE */
Commit	Line	Data
1656cbed	1	/* $OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $ */
1656cbed	2
3159d49a	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)
1656cbed	31	static const char rcsid[] = "$OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $";
3159d49a	32	#endif /* LIBC_SCCS and not lint */
	33
	34	#include "includes.h"
	35
	36	#ifndef HAVE_READPASSPHRASE
	37
	38	#include <termios.h>
	39	#include <readpassphrase.h>
	40
	41	#ifdef TCSASOFT
	42	# define _T_FLUSH (TCSAFLUSH\|TCSASOFT)
	43	#else
	44	# define _T_FLUSH (TCSAFLUSH)
	45	#endif
	46
d321c94b	47	/* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
	48	#if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
	49	# define _POSIX_VDISABLE VDISABLE
	50	#endif
	51
1656cbed	52	static volatile sig_atomic_t signo;
	53
	54	static void handler(int);
	55
3159d49a	56	char *
1656cbed	57	readpassphrase(const char prompt, char buf, size_t bufsiz, int flags)
3159d49a	58	{
1656cbed	59	ssize_t nr;
1656cbed	60	int input, output, save_errno;
3159d49a	61	char ch, p, end;
1656cbed	62	struct termios term, oterm;
	63	struct sigaction sa, saveint, savehup, savequit, saveterm;
	64	struct sigaction savetstp, savettin, savettou;
3159d49a	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
1656cbed	72	restart:
3159d49a	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	/*
1656cbed	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.
3159d49a	90	*/
1656cbed	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);
3159d49a	101
3159d49a	102	/* Turn off echo if possible. */
1656cbed	103	if (tcgetattr(input, &oterm) == 0) {
	104	memcpy(&term, &oterm, sizeof(term));
	105	if (!(flags & RPP_ECHO_ON))
	106	term.c_lflag &= ~(ECHO \| ECHONL);
3159d49a	107	#ifdef VSTATUS
1656cbed	108	if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
3159d49a	109	term.c_cc[VSTATUS] = _POSIX_VDISABLE;
3159d49a	110	#endif
3159d49a	111	(void)tcsetattr(input, _T_FLUSH, &term);
1656cbed	112	} else {
	113	memset(&term, 0, sizeof(term));
	114	memset(&oterm, 0, sizeof(oterm));
3159d49a	115	}
	116
	117	(void)write(output, prompt, strlen(prompt));
	118	end = buf + bufsiz - 1;
1656cbed	119	for (p = buf; (nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) {
3159d49a	120	if (p < end) {
3159d49a	121	if ((flags & RPP_SEVENBIT))
0eb1a22d	122	ch &= 0x7f;
3159d49a	123	if (isalpha(ch)) {
	124	if ((flags & RPP_FORCELOWER))
	125	ch = tolower(ch);
	126	if ((flags & RPP_FORCEUPPER))
	127	ch = toupper(ch);
	128	}
	129	*p++ = ch;
	130	}
	131	}
	132	*p = '\0';
1656cbed	133	save_errno = errno;
	134	if (!(term.c_lflag & ECHO))
	135	(void)write(output, "\n", 1);
	136
	137	/* Restore old terminal settings and signals. */
	138	if (memcmp(&term, &oterm, sizeof(term)) != 0)
969d6479	139	(void)tcsetattr(input, _T_FLUSH, &oterm);
1656cbed	140	(void)sigaction(SIGINT, &saveint, NULL);
	141	(void)sigaction(SIGHUP, &savehup, NULL);
	142	(void)sigaction(SIGQUIT, &savequit, NULL);
	143	(void)sigaction(SIGTERM, &saveterm, NULL);
	144	(void)sigaction(SIGTSTP, &savetstp, NULL);
	145	(void)sigaction(SIGTTIN, &savettin, NULL);
	146	(void)sigaction(SIGTTOU, &savettou, NULL);
3159d49a	147	if (input != STDIN_FILENO)
3159d49a	148	(void)close(input);
1656cbed	149
	150	/*
	151	* If we were interrupted by a signal, resend it to ourselves
	152	* now that we have restored the signal handlers.
	153	*/
	154	if (signo) {
	155	kill(getpid(), signo);
	156	switch (signo) {
	157	case SIGTSTP:
	158	case SIGTTIN:
	159	case SIGTTOU:
	160	signo = 0;
	161	goto restart;
	162	}
	163	}
	164
	165	errno = save_errno;
	166	return(nr == -1 ? NULL : buf);
3159d49a	167	}
1656cbed	168
3159d49a	169	#if 0
3159d49a	170	char *
1656cbed	171	getpass(const char *prompt)
3159d49a	172	{
	173	static char buf[_PASSWORD_LEN + 1];
	174
	175	return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
	176	}
	177	#endif
1656cbed	178
	179	static void handler(int s)
	180	{
1656cbed	181	signo = s;
1656cbed	182	}
50903cc7	183	#endif /* HAVE_READPASSPHRASE */