[gssapi-openssh.git] / openssh / readpass.c

/*
 * Copyright (c) 1988, 1993
 *      The Regents of the University of California.  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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 */

#include "includes.h"
RCSID("$OpenBSD: readpass.c,v 1.23 2001/11/08 10:51:08 markus Exp $");

#include "xmalloc.h"
#include "readpass.h"
#include "pathnames.h"
#include "log.h"
#include "ssh.h"

static char *
ssh_askpass(char *askpass, const char *msg)
{
	pid_t pid;
	size_t len;
	char *pass;
	int p[2], status;
	char buf[1024];

	if (fflush(stdout) != 0)
		error("ssh_askpass: fflush: %s", strerror(errno));
	if (askpass == NULL)
		fatal("internal error: askpass undefined");
	if (pipe(p) < 0) {
		error("ssh_askpass: pipe: %s", strerror(errno));
		return xstrdup("");
	}
	if ((pid = fork()) < 0) {
		error("ssh_askpass: fork: %s", strerror(errno));
		return xstrdup("");
	}
	if (pid == 0) {
		seteuid(getuid());
		setuid(getuid());
		close(p[0]);
		if (dup2(p[1], STDOUT_FILENO) < 0)
			fatal("ssh_askpass: dup2: %s", strerror(errno));
		execlp(askpass, askpass, msg, (char *) 0);
		fatal("ssh_askpass: exec(%s): %s", askpass, strerror(errno));
	}
	close(p[1]);
	len = read(p[0], buf, sizeof buf -1);
	close(p[0]);
	while (waitpid(pid, &status, 0) < 0)
		if (errno != EINTR)
			break;
	if (len <= 1)
		return xstrdup("");
	buf[len] = '\0';
	buf[strcspn(buf, "\r\n")] = '\0';
	pass = xstrdup(buf);
	memset(buf, 0, sizeof(buf));
	return pass;
}

/*
 * Reads a passphrase from /dev/tty with echo turned off/on.  Returns the
 * passphrase (allocated with xmalloc).  Exits if EOF is encountered. If
 * RP_ALLOW_STDIN is set, the passphrase will be read from stdin if no
 * tty is available
 */
char *
read_passphrase(const char *prompt, int flags)
{
	char *askpass = NULL, *ret, buf[1024];
	int rppflags, use_askpass = 0, ttyfd;

	rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
	if (flags & RP_ALLOW_STDIN) {
		if (!isatty(STDIN_FILENO))
			use_askpass = 1;
	} else {
		rppflags |= RPP_REQUIRE_TTY;
		ttyfd = open("/dev/tty", O_RDWR);
		if (ttyfd >= 0)
			close(ttyfd);
		else
			use_askpass = 1;
	}

	if (use_askpass && getenv("DISPLAY")) {
		if (getenv(SSH_ASKPASS_ENV))
			askpass = getenv(SSH_ASKPASS_ENV);
		else
			askpass = _PATH_SSH_ASKPASS_DEFAULT;
		return ssh_askpass(askpass, prompt);
	}

	if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL)
		return xstrdup("");

	ret = xstrdup(buf);
	memset(buf, 'x', sizeof buf);
	return ret;
}
Commit	Line	Data
3c0ef626	1	/*
	2	* Copyright (c) 1988, 1993
	3	* The Regents of the University of California. 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	#include "includes.h"
	35	RCSID("$OpenBSD: readpass.c,v 1.23 2001/11/08 10:51:08 markus Exp $");
	36
	37	#include "xmalloc.h"
	38	#include "readpass.h"
	39	#include "pathnames.h"
	40	#include "log.h"
	41	#include "ssh.h"
	42
	43	static char *
	44	ssh_askpass(char askpass, const char msg)
	45	{
	46	pid_t pid;
	47	size_t len;
	48	char *pass;
	49	int p[2], status;
	50	char buf[1024];
	51
	52	if (fflush(stdout) != 0)
	53	error("ssh_askpass: fflush: %s", strerror(errno));
	54	if (askpass == NULL)
	55	fatal("internal error: askpass undefined");
	56	if (pipe(p) < 0) {
	57	error("ssh_askpass: pipe: %s", strerror(errno));
	58	return xstrdup("");
	59	}
	60	if ((pid = fork()) < 0) {
	61	error("ssh_askpass: fork: %s", strerror(errno));
	62	return xstrdup("");
	63	}
	64	if (pid == 0) {
65	seteuid(getuid());
66	setuid(getuid());
67	close(p[0]);
68	if (dup2(p[1], STDOUT_FILENO) < 0)
69	fatal("ssh_askpass: dup2: %s", strerror(errno));
70	execlp(askpass, askpass, msg, (char *) 0);
71	fatal("ssh_askpass: exec(%s): %s", askpass, strerror(errno));
72	}
73	close(p[1]);
74	len = read(p[0], buf, sizeof buf -1);
75	close(p[0]);
76	while (waitpid(pid, &status, 0) < 0)
77	if (errno != EINTR)
78	break;
79	if (len <= 1)
80	return xstrdup("");
81	buf[len] = '\0';
82	buf[strcspn(buf, "\r\n")] = '\0';
83	pass = xstrdup(buf);
84	memset(buf, 0, sizeof(buf));
85	return pass;
86	}
87
88	/*
89	* Reads a passphrase from /dev/tty with echo turned off/on. Returns the
90	* passphrase (allocated with xmalloc). Exits if EOF is encountered. If
91	* RP_ALLOW_STDIN is set, the passphrase will be read from stdin if no
92	* tty is available
93	*/
94	char *
95	read_passphrase(const char *prompt, int flags)
96	{
97	char askpass = NULL, ret, buf[1024];
98	int rppflags, use_askpass = 0, ttyfd;
99
100	rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
101	if (flags & RP_ALLOW_STDIN) {
102	if (!isatty(STDIN_FILENO))
103	use_askpass = 1;
104	} else {
105	rppflags \|= RPP_REQUIRE_TTY;
106	ttyfd = open("/dev/tty", O_RDWR);
107	if (ttyfd >= 0)
108	close(ttyfd);
109	else
110	use_askpass = 1;
111	}
112
113	if (use_askpass && getenv("DISPLAY")) {
114	if (getenv(SSH_ASKPASS_ENV))
115	askpass = getenv(SSH_ASKPASS_ENV);
116	else
117	askpass = _PATH_SSH_ASKPASS_DEFAULT;
118	return ssh_askpass(askpass, prompt);
119	}
120
121	if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL)
122	return xstrdup("");
123
124	ret = xstrdup(buf);
125	memset(buf, 'x', sizeof buf);
126	return ret;
127	}