diff options
Diffstat (limited to 'usr.bin')
| -rw-r--r-- | usr.bin/ssh/readpass.c | 167 |
1 files changed, 71 insertions, 96 deletions
diff --git a/usr.bin/ssh/readpass.c b/usr.bin/ssh/readpass.c index b1e58a64d54..6d1134e4c32 100644 --- a/usr.bin/ssh/readpass.c +++ b/usr.bin/ssh/readpass.c @@ -1,119 +1,94 @@ /* - * - * readpass.c - * - * Author: Tatu Ylonen <ylo@cs.hut.fi> - * - * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland - * All rights reserved - * - * Created: Mon Jul 10 22:08:59 1995 ylo - * - * Functions for reading passphrases and passwords. - * + * 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("$Id: readpass.c,v 1.7 1999/11/24 19:53:50 markus Exp $"); +RCSID("$Id: readpass.c,v 1.8 1999/12/08 19:32:55 deraadt Exp $"); #include "xmalloc.h" #include "ssh.h" -/* Saved old terminal mode for read_passphrase. */ -static struct termios saved_tio; - -/* Old interrupt signal handler for read_passphrase. */ -static void (*old_handler) (int sig) = NULL; - -/* Interrupt signal handler for read_passphrase. */ - -void -intr_handler(int sig) -{ - /* Restore terminal modes. */ - tcsetattr(fileno(stdin), TCSANOW, &saved_tio); - /* Restore the old signal handler. */ - signal(sig, old_handler); - /* Resend the signal, with the old handler. */ - kill(getpid(), sig); -} - /* * Reads a passphrase from /dev/tty with echo turned off. Returns the - * passphrase (allocated with xmalloc). Exits if EOF is encountered. The - * passphrase if read from stdin if from_stdin is true (as is the case with - * ssh-keygen). + * 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], *cp; - struct termios tio; - FILE *f; + char buf[1024], *p, ch; + struct termios tio, saved_tio; + sigset_t oset, nset; + 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"); - if (from_stdin) - f = stdin; - else { - /* - * Read the passphrase from /dev/tty to make it possible to - * ask it even when stdin has been redirected. - */ - f = fopen("/dev/tty", "r"); - if (!f) { - /* No controlling terminal and no DISPLAY. Nowhere to read. */ - fprintf(stderr, "You have no controlling tty and no DISPLAY. Cannot read passphrase.\n"); - exit(1); - } + /* block signals, get terminal modes and turn off echo */ + sigemptyset(&nset); + sigaddset(&nset, SIGINT); + sigaddset(&nset, SIGTSTP); + (void) sigprocmask(SIG_BLOCK, &nset, &oset); + + if (tcgetattr(input, &tio) == 0 && (tio.c_lflag & ECHO)) { + echo = 1; + saved_tio = tio; + tio.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL); + (void) tcsetattr(input, TCSANOW, &tio); } - /* Display the prompt (on stderr because stdout might be redirected). */ fflush(stdout); - fprintf(stderr, "%s", prompt); - fflush(stderr); - /* Get terminal modes. */ - tcgetattr(fileno(f), &tio); - saved_tio = tio; - /* Save signal handler and set the new handler. */ - old_handler = signal(SIGINT, intr_handler); + (void)write(output, prompt, strlen(prompt)); + for (p = buf; read(input, &ch, 1) == 1 && ch != '\n';) + if (p < buf + sizeof(buf) - 1) + *p++ = ch; + *p = '\0'; + (void)write(output, "\n", 1); - /* Set new terminal modes disabling all echo. */ - tio.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL); - tcsetattr(fileno(f), TCSANOW, &tio); + /* restore terminal modes and allow signals */ + if (echo) + tcsetattr(input, TCSANOW, &saved_tio); + (void) sigprocmask(SIG_SETMASK, &oset, NULL); - /* Read the passphrase from the terminal. */ - if (fgets(buf, sizeof(buf), f) == NULL) { - /* Got EOF. Just exit. */ - /* Restore terminal modes. */ - tcsetattr(fileno(f), TCSANOW, &saved_tio); - /* Restore the signal handler. */ - signal(SIGINT, old_handler); - /* Print a newline (the prompt probably didn\'t have one). */ - fprintf(stderr, "\n"); - /* Close the file. */ - if (f != stdin) - fclose(f); - exit(1); - } - /* Restore terminal modes. */ - tcsetattr(fileno(f), TCSANOW, &saved_tio); - /* Restore the signal handler. */ - (void) signal(SIGINT, old_handler); - /* Remove newline from the passphrase. */ - if (strchr(buf, '\n')) - *strchr(buf, '\n') = 0; - /* Allocate a copy of the passphrase. */ - cp = xstrdup(buf); - /* - * Clear the buffer so we don\'t leave copies of the passphrase - * laying around. - */ + if (!from_stdin) + (void)close(input); + p = xstrdup(buf); memset(buf, 0, sizeof(buf)); - /* Print a newline since the prompt probably didn\'t have one. */ - fprintf(stderr, "\n"); - /* Close the file. */ - if (f != stdin) - fclose(f); - return cp; + return (p); } |