1 /* $OpenBSD: readpassphrase.c,v 1.16 2003/06/17 21:56:23 millert Exp $ */ 2 3 /* 4 * Copyright (c) 2000-2002 Todd C. Miller <Todd.Miller@courtesan.com> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 * 18 * Sponsored in part by the Defense Advanced Research Projects 19 * Agency (DARPA) and Air Force Research Laboratory, Air Force 20 * Materiel Command, USAF, under agreement number F39502-99-1-0512. 21 */ 22 23 #if defined(LIBC_SCCS) && !defined(lint) 24 static const char rcsid[] = "$OpenBSD: readpassphrase.c,v 1.16 2003/06/17 21:56:23 millert Exp $"; 25 #endif /* LIBC_SCCS and not lint */ 26 27 #include "includes.h" 28 29 #ifndef HAVE_READPASSPHRASE 30 31 #include <termios.h> 32 #include <readpassphrase.h> 33 34 #ifdef TCSASOFT 35 # define _T_FLUSH (TCSAFLUSH|TCSASOFT) 36 #else 37 # define _T_FLUSH (TCSAFLUSH) 38 #endif 39 40 /* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */ 41 #if !defined(_POSIX_VDISABLE) && defined(VDISABLE) 42 # define _POSIX_VDISABLE VDISABLE 43 #endif 44 45 static volatile sig_atomic_t signo; 46 47 static void handler(int); 48 49 char * 50 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags) 51 { 52 ssize_t nr; 53 int input, output, save_errno; 54 char ch, *p, *end; 55 struct termios term, oterm; 56 struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm; 57 struct sigaction savetstp, savettin, savettou, savepipe; 58 59 /* I suppose we could alloc on demand in this case (XXX). */ 60 if (bufsiz == 0) { 61 errno = EINVAL; 62 return(NULL); 63 } 64 65 restart: 66 signo = 0; 67 /* 68 * Read and write to /dev/tty if available. If not, read from 69 * stdin and write to stderr unless a tty is required. 70 */ 71 if ((flags & RPP_STDIN) || 72 (input = output = open(_PATH_TTY, O_RDWR)) == -1) { 73 if (flags & RPP_REQUIRE_TTY) { 74 errno = ENOTTY; 75 return(NULL); 76 } 77 input = STDIN_FILENO; 78 output = STDERR_FILENO; 79 } 80 81 /* 82 * Catch signals that would otherwise cause the user to end 83 * up with echo turned off in the shell. Don't worry about 84 * things like SIGXCPU and SIGVTALRM for now. 85 */ 86 sigemptyset(&sa.sa_mask); 87 sa.sa_flags = 0; /* don't restart system calls */ 88 sa.sa_handler = handler; 89 (void)sigaction(SIGALRM, &sa, &savealrm); 90 (void)sigaction(SIGHUP, &sa, &savehup); 91 (void)sigaction(SIGINT, &sa, &saveint); 92 (void)sigaction(SIGPIPE, &sa, &savepipe); 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 (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) { 101 memcpy(&term, &oterm, sizeof(term)); 102 if (!(flags & RPP_ECHO_ON)) 103 term.c_lflag &= ~(ECHO | ECHONL); 104 #ifdef VSTATUS 105 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE) 106 term.c_cc[VSTATUS] = _POSIX_VDISABLE; 107 #endif 108 (void)tcsetattr(input, _T_FLUSH, &term); 109 } else { 110 memset(&term, 0, sizeof(term)); 111 term.c_lflag |= ECHO; 112 memset(&oterm, 0, sizeof(oterm)); 113 oterm.c_lflag |= ECHO; 114 } 115 116 if (!(flags & RPP_STDIN)) 117 (void)write(output, prompt, strlen(prompt)); 118 end = buf + bufsiz - 1; 119 for (p = buf; (nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) { 120 if (p < end) { 121 if ((flags & RPP_SEVENBIT)) 122 ch &= 0x7f; 123 if (isalpha(ch)) { 124 if ((flags & RPP_FORCELOWER)) 125 ch = tolower(ch); 126 if ((flags & RPP_FORCEUPPER)) 127 ch = toupper(ch); 128 } 129 *p++ = ch; 130 } 131 } 132 *p = '\0'; 133 save_errno = errno; 134 if (!(term.c_lflag & ECHO)) 135 (void)write(output, "\n", 1); 136 137 /* Restore old terminal settings and signals. */ 138 if (memcmp(&term, &oterm, sizeof(term)) != 0) 139 (void)tcsetattr(input, _T_FLUSH, &oterm); 140 (void)sigaction(SIGALRM, &savealrm, NULL); 141 (void)sigaction(SIGHUP, &savehup, NULL); 142 (void)sigaction(SIGINT, &saveint, NULL); 143 (void)sigaction(SIGQUIT, &savequit, NULL); 144 (void)sigaction(SIGPIPE, &savepipe, NULL); 145 (void)sigaction(SIGTERM, &saveterm, NULL); 146 (void)sigaction(SIGTSTP, &savetstp, NULL); 147 (void)sigaction(SIGTTIN, &savettin, NULL); 148 if (input != STDIN_FILENO) 149 (void)close(input); 150 151 /* 152 * If we were interrupted by a signal, resend it to ourselves 153 * now that we have restored the signal handlers. 154 */ 155 if (signo) { 156 kill(getpid(), signo); 157 switch (signo) { 158 case SIGTSTP: 159 case SIGTTIN: 160 case SIGTTOU: 161 goto restart; 162 } 163 } 164 165 errno = save_errno; 166 return(nr == -1 ? NULL : buf); 167 } 168 169 #if 0 170 char * 171 getpass(const char *prompt) 172 { 173 static char buf[_PASSWORD_LEN + 1]; 174 175 return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF)); 176 } 177 #endif 178 179 static void handler(int s) 180 { 181 182 signo = s; 183 } 184 #endif /* HAVE_READPASSPHRASE */ 185