openssh/readpass.c

120 lines
3.7 KiB
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 1.11 2000/06/20 01:39:44 markus Exp $");
#include "xmalloc.h"
#include "ssh.h"
volatile int intr;
void
intcatch()
{
intr = 1;
}
/*
* Reads a passphrase from /dev/tty with echo turned off. Returns the
* passphrase (allocated with xmalloc), being very careful to ensure that
* no other userland buffer is storing the password.
*/
char *
read_passphrase(const char *prompt, int from_stdin)
{
char buf[1024], *p, ch;
struct termios tio, saved_tio;
sigset_t oset, nset;
struct sigaction sa, osa;
int input, output, echo = 0;
if (from_stdin) {
input = STDIN_FILENO;
output = STDERR_FILENO;
} else
input = output = open("/dev/tty", O_RDWR);
if (input == -1)
fatal("You have no controlling tty. Cannot read passphrase.\n");
/* block signals, get terminal modes and turn off echo */
sigemptyset(&nset);
sigaddset(&nset, SIGTSTP);
(void) sigprocmask(SIG_BLOCK, &nset, &oset);
memset(&sa, 0, sizeof(sa));
sa.sa_handler = intcatch;
(void) sigaction(SIGINT, &sa, &osa);
intr = 0;
if (tcgetattr(input, &saved_tio) == 0 && (saved_tio.c_lflag & ECHO)) {
echo = 1;
tio = saved_tio;
tio.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
(void) tcsetattr(input, TCSANOW, &tio);
}
fflush(stdout);
(void)write(output, prompt, strlen(prompt));
for (p = buf; read(input, &ch, 1) == 1 && ch != '\n';) {
if (intr)
break;
if (p < buf + sizeof(buf) - 1)
*p++ = ch;
}
*p = '\0';
if (!intr)
(void)write(output, "\n", 1);
/* restore terminal modes and allow signals */
if (echo)
tcsetattr(input, TCSANOW, &saved_tio);
(void) sigprocmask(SIG_SETMASK, &oset, NULL);
(void) sigaction(SIGINT, &osa, NULL);
if (intr) {
kill(getpid(), SIGINT);
sigemptyset(&nset);
/* XXX tty has not neccessarily drained by now? */
sigsuspend(&nset);
}
if (!from_stdin)
(void)close(input);
p = xstrdup(buf);
memset(buf, 0, sizeof(buf));
return (p);
}