readpassphrase_compat.h
1 /* $OpenBSD: readpassphrase.c,v 1.24 2013/11/24 23:51:29 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 2000-2002, 2007, 2010 5 * Todd C. Miller <Todd.Miller@courtesan.com> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 * 19 * Sponsored in part by the Defense Advanced Research Projects 20 * Agency (DARPA) and Air Force Research Laboratory, Air Force 21 * Materiel Command, USAF, under agreement number F39502-99-1-0512. 22 */ 23 24 #ifndef READPASSPHRASE_COMPAT_H 25 #define READPASSPHRASE_COMPAT_H 26 27 #include <ctype.h> 28 #include <errno.h> 29 #include <fcntl.h> 30 #include <paths.h> 31 #include <pwd.h> 32 #include <signal.h> 33 #include <string.h> 34 #include <termios.h> 35 #include <unistd.h> 36 37 #define RPP_ECHO_OFF 0x00 /* Turn off echo (default). */ 38 #define RPP_ECHO_ON 0x01 /* Leave echo on. */ 39 #define RPP_REQUIRE_TTY 0x02 /* Fail if there is no tty. */ 40 #define RPP_FORCELOWER 0x04 /* Force input to lower case. */ 41 #define RPP_FORCEUPPER 0x08 /* Force input to upper case. */ 42 #define RPP_SEVENBIT 0x10 /* Strip the high bit from input. */ 43 #define RPP_STDIN 0x20 /* Read from stdin, not /dev/tty */ 44 45 #ifndef _NSIG 46 #define _NSIG 32 47 #endif 48 49 static volatile sig_atomic_t signo[_NSIG]; 50 static void handler(int); 51 52 static char * 53 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags) 54 { 55 ssize_t nr; 56 int input, output, save_errno, i, need_restart; 57 char ch, *p, *end; 58 struct termios term, oterm; 59 struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm; 60 struct sigaction savetstp, savettin, savettou, savepipe; 61 62 /* I suppose we could alloc on demand in this case (XXX). */ 63 if (bufsiz == 0) { 64 errno = EINVAL; 65 return(NULL); 66 } 67 68 restart: 69 for (i = 0; i < _NSIG; i++) 70 signo[i] = 0; 71 nr = -1; 72 save_errno = 0; 73 need_restart = 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("/dev/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 * Turn off echo if possible. 90 * If we are using a tty but are not the foreground pgrp this will 91 * generate SIGTTOU, so do it *before* installing the signal handlers. 92 */ 93 if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) { 94 memcpy(&term, &oterm, sizeof(term)); 95 if (!(flags & RPP_ECHO_ON)) 96 term.c_lflag &= ~(ECHO | ECHONL); 97 (void)tcsetattr(input, TCSAFLUSH, &term); 98 } else { 99 memset(&term, 0, sizeof(term)); 100 term.c_lflag |= ECHO; 101 memset(&oterm, 0, sizeof(oterm)); 102 oterm.c_lflag |= ECHO; 103 } 104 105 /* 106 * Catch signals that would otherwise cause the user to end 107 * up with echo turned off in the shell. Don't worry about 108 * things like SIGXCPU and SIGVTALRM for now. 109 */ 110 sigemptyset(&sa.sa_mask); 111 sa.sa_flags = 0; /* don't restart system calls */ 112 sa.sa_handler = handler; 113 (void)sigaction(SIGALRM, &sa, &savealrm); 114 (void)sigaction(SIGHUP, &sa, &savehup); 115 (void)sigaction(SIGINT, &sa, &saveint); 116 (void)sigaction(SIGPIPE, &sa, &savepipe); 117 (void)sigaction(SIGQUIT, &sa, &savequit); 118 (void)sigaction(SIGTERM, &sa, &saveterm); 119 (void)sigaction(SIGTSTP, &sa, &savetstp); 120 (void)sigaction(SIGTTIN, &sa, &savettin); 121 (void)sigaction(SIGTTOU, &sa, &savettou); 122 123 if (!(flags & RPP_STDIN)) 124 (void)write(output, prompt, strlen(prompt)); 125 end = buf + bufsiz - 1; 126 p = buf; 127 while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') { 128 if (p < end) { 129 if ((flags & RPP_SEVENBIT)) 130 ch &= 0x7f; 131 if (isalpha((unsigned char)ch)) { 132 if ((flags & RPP_FORCELOWER)) 133 ch = (char)tolower((unsigned char)ch); 134 if ((flags & RPP_FORCEUPPER)) 135 ch = (char)toupper((unsigned char)ch); 136 } 137 *p++ = ch; 138 } 139 } 140 *p = '\0'; 141 save_errno = errno; 142 if (!(term.c_lflag & ECHO)) 143 (void)write(output, "\n", 1); 144 145 /* Restore old terminal settings and signals. */ 146 if (memcmp(&term, &oterm, sizeof(term)) != 0) { 147 while (tcsetattr(input, TCSAFLUSH, &oterm) == -1 && 148 errno == EINTR && !signo[SIGTTOU]) 149 continue; 150 } 151 (void)sigaction(SIGALRM, &savealrm, NULL); 152 (void)sigaction(SIGHUP, &savehup, NULL); 153 (void)sigaction(SIGINT, &saveint, NULL); 154 (void)sigaction(SIGQUIT, &savequit, NULL); 155 (void)sigaction(SIGPIPE, &savepipe, NULL); 156 (void)sigaction(SIGTERM, &saveterm, NULL); 157 (void)sigaction(SIGTSTP, &savetstp, NULL); 158 (void)sigaction(SIGTTIN, &savettin, NULL); 159 (void)sigaction(SIGTTOU, &savettou, NULL); 160 if (input != STDIN_FILENO) 161 (void)close(input); 162 163 /* 164 * If we were interrupted by a signal, resend it to ourselves 165 * now that we have restored the signal handlers. 166 */ 167 for (i = 0; i < _NSIG; i++) { 168 if (signo[i]) { 169 kill(getpid(), i); 170 switch (i) { 171 case SIGTSTP: 172 case SIGTTIN: 173 case SIGTTOU: 174 need_restart = 1; 175 } 176 } 177 } 178 if (need_restart) 179 goto restart; 180 181 if (save_errno) 182 errno = save_errno; 183 return(nr == -1 ? NULL : buf); 184 } 185 186 static void handler(int s) 187 { 188 189 signo[s] = 1; 190 } 191 192 #endif