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("$Id: readpass.c,v 1.9 2000/01/21 21:16:00 deraadt Exp $"); 36 37 #include "xmalloc.h" 38 #include "ssh.h" 39 40 volatile int intr; 41 42 void 43 intcatch() 44 { 45 intr = 1; 46 } 47 48 /* 49 * Reads a passphrase from /dev/tty with echo turned off. Returns the 50 * passphrase (allocated with xmalloc), being very careful to ensure that 51 * no other userland buffer is storing the password. 52 */ 53 char * 54 read_passphrase(const char *prompt, int from_stdin) 55 { 56 char buf[1024], *p, ch; 57 struct termios tio, saved_tio; 58 sigset_t oset, nset; 59 struct sigaction sa, osa; 60 int input, output, echo = 0; 61 62 if (from_stdin) { 63 input = STDIN_FILENO; 64 output = STDERR_FILENO; 65 } else 66 input = output = open("/dev/tty", O_RDWR); 67 68 if (input == -1) 69 fatal("You have no controlling tty. Cannot read passphrase.\n"); 70 71 /* block signals, get terminal modes and turn off echo */ 72 sigemptyset(&nset); 73 sigaddset(&nset, SIGTSTP); 74 (void) sigprocmask(SIG_BLOCK, &nset, &oset); 75 memset(&sa, 0, sizeof(sa)); 76 sa.sa_handler = intcatch; 77 (void) sigaction(SIGINT, &sa, &osa); 78 79 intr = 0; 80 81 if (tcgetattr(input, &saved_tio) == 0 && (saved_tio.c_lflag & ECHO)) { 82 echo = 1; 83 tio = saved_tio; 84 tio.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL); 85 (void) tcsetattr(input, TCSANOW, &tio); 86 } 87 88 fflush(stdout); 89 90 (void)write(output, prompt, strlen(prompt)); 91 for (p = buf; read(input, &ch, 1) == 1 && ch != '\n';) { 92 if (intr) 93 break; 94 if (p < buf + sizeof(buf) - 1) 95 *p++ = ch; 96 } 97 *p = '\0'; 98 if (!intr) 99 (void)write(output, "\n", 1); 100 101 /* restore terminal modes and allow signals */ 102 if (echo) 103 tcsetattr(input, TCSANOW, &saved_tio); 104 (void) sigprocmask(SIG_SETMASK, &oset, NULL); 105 (void) sigaction(SIGINT, &osa, NULL); 106 107 if (intr) { 108 kill(getpid(), SIGINT); 109 sigemptyset(&nset); 110 /* XXX tty has not neccessarily drained by now? */ 111 sigsuspend(&nset); 112 } 113 114 if (!from_stdin) 115 (void)close(input); 116 p = xstrdup(buf); 117 memset(buf, 0, sizeof(buf)); 118 return (p); 119 } 120