1 /* $OpenBSD: readpassphrase.c,v 1.14 2002/06/28 01:43:58 millert Exp $ */ 2 3 /* 4 * Copyright (c) 2000-2002 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) 31 static const char rcsid[] = "$OpenBSD: readpassphrase.c,v 1.14 2002/06/28 01:43:58 millert Exp $"; 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 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 52 static volatile sig_atomic_t signo; 53 54 static void handler(int); 55 56 char * 57 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags) 58 { 59 ssize_t nr; 60 int input, output, save_errno; 61 char ch, *p, *end; 62 struct termios term, oterm; 63 struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm; 64 struct sigaction savetstp, savettin, savettou, savepipe; 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 72 restart: 73 signo = 0; 74 /* 75 * Read and write to /dev/tty if available. If not, read from 76 * stdin and write to stderr unless a tty is required. 77 */ 78 if ((flags & RPP_STDIN) || 79 (input = output = open(_PATH_TTY, O_RDWR)) == -1) { 80 if (flags & RPP_REQUIRE_TTY) { 81 errno = ENOTTY; 82 return(NULL); 83 } 84 input = STDIN_FILENO; 85 output = STDERR_FILENO; 86 } 87 88 /* 89 * Catch signals that would otherwise cause the user to end 90 * up with echo turned off in the shell. Don't worry about 91 * things like SIGXCPU and SIGVTALRM for now. 92 */ 93 sigemptyset(&sa.sa_mask); 94 sa.sa_flags = 0; /* don't restart system calls */ 95 sa.sa_handler = handler; 96 (void)sigaction(SIGALRM, &sa, &savealrm); 97 (void)sigaction(SIGHUP, &sa, &savehup); 98 (void)sigaction(SIGINT, &sa, &saveint); 99 (void)sigaction(SIGPIPE, &sa, &savepipe); 100 (void)sigaction(SIGQUIT, &sa, &savequit); 101 (void)sigaction(SIGTERM, &sa, &saveterm); 102 (void)sigaction(SIGTSTP, &sa, &savetstp); 103 (void)sigaction(SIGTTIN, &sa, &savettin); 104 (void)sigaction(SIGTTOU, &sa, &savettou); 105 106 /* Turn off echo if possible. */ 107 if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) { 108 memcpy(&term, &oterm, sizeof(term)); 109 if (!(flags & RPP_ECHO_ON)) 110 term.c_lflag &= ~(ECHO | ECHONL); 111 #ifdef VSTATUS 112 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE) 113 term.c_cc[VSTATUS] = _POSIX_VDISABLE; 114 #endif 115 (void)tcsetattr(input, _T_FLUSH, &term); 116 } else { 117 memset(&term, 0, sizeof(term)); 118 term.c_lflag |= ECHO; 119 memset(&oterm, 0, sizeof(oterm)); 120 oterm.c_lflag |= ECHO; 121 } 122 123 if (!(flags & RPP_STDIN)) 124 (void)write(output, prompt, strlen(prompt)); 125 end = buf + bufsiz - 1; 126 for (p = buf; (nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) { 127 if (p < end) { 128 if ((flags & RPP_SEVENBIT)) 129 ch &= 0x7f; 130 if (isalpha(ch)) { 131 if ((flags & RPP_FORCELOWER)) 132 ch = tolower(ch); 133 if ((flags & RPP_FORCEUPPER)) 134 ch = toupper(ch); 135 } 136 *p++ = ch; 137 } 138 } 139 *p = '\0'; 140 save_errno = errno; 141 if (!(term.c_lflag & ECHO)) 142 (void)write(output, "\n", 1); 143 144 /* Restore old terminal settings and signals. */ 145 if (memcmp(&term, &oterm, sizeof(term)) != 0) 146 (void)tcsetattr(input, _T_FLUSH, &oterm); 147 (void)sigaction(SIGALRM, &savealrm, NULL); 148 (void)sigaction(SIGHUP, &savehup, NULL); 149 (void)sigaction(SIGINT, &saveint, NULL); 150 (void)sigaction(SIGQUIT, &savequit, NULL); 151 (void)sigaction(SIGPIPE, &savepipe, NULL); 152 (void)sigaction(SIGTERM, &saveterm, NULL); 153 (void)sigaction(SIGTSTP, &savetstp, NULL); 154 (void)sigaction(SIGTTIN, &savettin, NULL); 155 if (input != STDIN_FILENO) 156 (void)close(input); 157 158 /* 159 * If we were interrupted by a signal, resend it to ourselves 160 * now that we have restored the signal handlers. 161 */ 162 if (signo) { 163 kill(getpid(), signo); 164 switch (signo) { 165 case SIGTSTP: 166 case SIGTTIN: 167 case SIGTTOU: 168 goto restart; 169 } 170 } 171 172 errno = save_errno; 173 return(nr == -1 ? NULL : buf); 174 } 175 176 #if 0 177 char * 178 getpass(const char *prompt) 179 { 180 static char buf[_PASSWORD_LEN + 1]; 181 182 return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF)); 183 } 184 #endif 185 186 static void handler(int s) 187 { 188 signo = s; 189 } 190 #endif /* HAVE_READPASSPHRASE */ 191 192 #pragma ident "%Z%%M% %I% %E% SMI" 193