1 /* $OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $ */ 2 3 /* 4 * Copyright (c) 2000 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 1.12 2001/12/15 05:41:00 millert Exp $"; 32 #endif /* LIBC_SCCS and not lint */ 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include "namespace.h" 37 #include <ctype.h> 38 #include <errno.h> 39 #include <fcntl.h> 40 #include <paths.h> 41 #include <pwd.h> 42 #include <signal.h> 43 #include <string.h> 44 #include <termios.h> 45 #include <unistd.h> 46 #include <readpassphrase.h> 47 #include "un-namespace.h" 48 49 static volatile sig_atomic_t signo; 50 51 static void handler(int); 52 53 char * 54 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags) 55 { 56 ssize_t nr; 57 int input, output, save_errno; 58 char ch, *p, *end; 59 struct termios term, oterm; 60 struct sigaction sa, saveint, savehup, savequit, saveterm; 61 struct sigaction savetstp, savettin, savettou; 62 63 /* I suppose we could alloc on demand in this case (XXX). */ 64 if (bufsiz == 0) { 65 errno = EINVAL; 66 return(NULL); 67 } 68 69 restart: 70 /* 71 * Read and write to /dev/tty if available. If not, read from 72 * stdin and write to stderr unless a tty is required. 73 */ 74 if ((input = output = _open(_PATH_TTY, O_RDWR)) == -1) { 75 if (flags & RPP_REQUIRE_TTY) { 76 errno = ENOTTY; 77 return(NULL); 78 } 79 input = STDIN_FILENO; 80 output = STDERR_FILENO; 81 } 82 83 /* 84 * Catch signals that would otherwise cause the user to end 85 * up with echo turned off in the shell. Don't worry about 86 * things like SIGALRM and SIGPIPE for now. 87 */ 88 sigemptyset(&sa.sa_mask); 89 sa.sa_flags = 0; /* don't restart system calls */ 90 sa.sa_handler = handler; 91 (void)_sigaction(SIGINT, &sa, &saveint); 92 (void)_sigaction(SIGHUP, &sa, &savehup); 93 (void)_sigaction(SIGQUIT, &sa, &savequit); 94 (void)_sigaction(SIGTERM, &sa, &saveterm); 95 (void)_sigaction(SIGTSTP, &sa, &savetstp); 96 (void)_sigaction(SIGTTIN, &sa, &savettin); 97 (void)_sigaction(SIGTTOU, &sa, &savettou); 98 99 /* Turn off echo if possible. */ 100 if (tcgetattr(input, &oterm) == 0) { 101 memcpy(&term, &oterm, sizeof(term)); 102 if (!(flags & RPP_ECHO_ON)) 103 term.c_lflag &= ~(ECHO | ECHONL); 104 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE) 105 term.c_cc[VSTATUS] = _POSIX_VDISABLE; 106 (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term); 107 } else { 108 memset(&term, 0, sizeof(term)); 109 memset(&oterm, 0, sizeof(oterm)); 110 } 111 112 (void)_write(output, prompt, strlen(prompt)); 113 end = buf + bufsiz - 1; 114 for (p = buf; (nr = _read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) { 115 if (p < end) { 116 if ((flags & RPP_SEVENBIT)) 117 ch &= 0x7f; 118 if (isalpha(ch)) { 119 if ((flags & RPP_FORCELOWER)) 120 ch = tolower(ch); 121 if ((flags & RPP_FORCEUPPER)) 122 ch = toupper(ch); 123 } 124 *p++ = ch; 125 } 126 } 127 *p = '\0'; 128 save_errno = errno; 129 if (!(term.c_lflag & ECHO)) 130 (void)_write(output, "\n", 1); 131 132 /* Restore old terminal settings and signals. */ 133 if (memcmp(&term, &oterm, sizeof(term)) != 0) 134 (void)tcsetattr(input, TCSANOW|TCSASOFT, &oterm); 135 (void)_sigaction(SIGINT, &saveint, NULL); 136 (void)_sigaction(SIGHUP, &savehup, NULL); 137 (void)_sigaction(SIGQUIT, &savequit, NULL); 138 (void)_sigaction(SIGTERM, &saveterm, NULL); 139 (void)_sigaction(SIGTSTP, &savetstp, NULL); 140 (void)_sigaction(SIGTTIN, &savettin, NULL); 141 (void)_sigaction(SIGTTOU, &savettou, NULL); 142 if (input != STDIN_FILENO) 143 (void)_close(input); 144 145 /* 146 * If we were interrupted by a signal, resend it to ourselves 147 * now that we have restored the signal handlers. 148 */ 149 if (signo) { 150 kill(getpid(), signo); 151 switch (signo) { 152 case SIGTSTP: 153 case SIGTTIN: 154 case SIGTTOU: 155 signo = 0; 156 goto restart; 157 } 158 } 159 160 errno = save_errno; 161 return(nr == -1 ? NULL : buf); 162 } 163 164 char * 165 getpass(const char *prompt) 166 { 167 static char buf[_PASSWORD_LEN + 1]; 168 169 if (readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF) == NULL) 170 buf[0] = '\0'; 171 return(buf); 172 } 173 174 static void handler(int s) 175 { 176 177 signo = s; 178 } 179