1 /* $OpenBSD: readpassphrase.c,v 1.26 2016/10/18 12:47:18 millert 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 /* OPENBSD ORIGINAL: lib/libc/gen/readpassphrase.c */ 25 26 #include "includes.h" 27 28 #ifndef HAVE_READPASSPHRASE 29 30 #include <termios.h> 31 #include <signal.h> 32 #include <ctype.h> 33 #include <fcntl.h> 34 #include <readpassphrase.h> 35 #include <errno.h> 36 #include <string.h> 37 #include <unistd.h> 38 39 #ifndef TCSASOFT 40 /* If we don't have TCSASOFT define it so that ORing it it below is a no-op. */ 41 # define TCSASOFT 0 42 #endif 43 44 /* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */ 45 #if !defined(_POSIX_VDISABLE) && defined(VDISABLE) 46 # define _POSIX_VDISABLE VDISABLE 47 #endif 48 49 static volatile sig_atomic_t signo[_NSIG]; 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, i, need_restart; 58 char ch, *p, *end; 59 struct termios term, oterm; 60 struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm; 61 struct sigaction savetstp, savettin, savettou, savepipe; 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 for (i = 0; i < _NSIG; i++) 71 signo[i] = 0; 72 nr = -1; 73 save_errno = 0; 74 need_restart = 0; 75 /* 76 * Read and write to /dev/tty if available. If not, read from 77 * stdin and write to stderr unless a tty is required. 78 */ 79 if ((flags & RPP_STDIN) || 80 (input = output = open(_PATH_TTY, O_RDWR)) == -1) { 81 if (flags & RPP_REQUIRE_TTY) { 82 errno = ENOTTY; 83 return(NULL); 84 } 85 input = STDIN_FILENO; 86 output = STDERR_FILENO; 87 } 88 89 /* 90 * Turn off echo if possible. 91 * If we are using a tty but are not the foreground pgrp this will 92 * generate SIGTTOU, so do it *before* installing the signal handlers. 93 */ 94 if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) { 95 memcpy(&term, &oterm, sizeof(term)); 96 if (!(flags & RPP_ECHO_ON)) 97 term.c_lflag &= ~(ECHO | ECHONL); 98 #ifdef VSTATUS 99 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE) 100 term.c_cc[VSTATUS] = _POSIX_VDISABLE; 101 #endif 102 (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term); 103 } else { 104 memset(&term, 0, sizeof(term)); 105 term.c_lflag |= ECHO; 106 memset(&oterm, 0, sizeof(oterm)); 107 oterm.c_lflag |= ECHO; 108 } 109 110 /* 111 * Catch signals that would otherwise cause the user to end 112 * up with echo turned off in the shell. Don't worry about 113 * things like SIGXCPU and SIGVTALRM for now. 114 */ 115 sigemptyset(&sa.sa_mask); 116 sa.sa_flags = 0; /* don't restart system calls */ 117 sa.sa_handler = handler; 118 (void)sigaction(SIGALRM, &sa, &savealrm); 119 (void)sigaction(SIGHUP, &sa, &savehup); 120 (void)sigaction(SIGINT, &sa, &saveint); 121 (void)sigaction(SIGPIPE, &sa, &savepipe); 122 (void)sigaction(SIGQUIT, &sa, &savequit); 123 (void)sigaction(SIGTERM, &sa, &saveterm); 124 (void)sigaction(SIGTSTP, &sa, &savetstp); 125 (void)sigaction(SIGTTIN, &sa, &savettin); 126 (void)sigaction(SIGTTOU, &sa, &savettou); 127 128 if (!(flags & RPP_STDIN)) 129 (void)write(output, prompt, strlen(prompt)); 130 end = buf + bufsiz - 1; 131 p = buf; 132 while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') { 133 if (p < end) { 134 if ((flags & RPP_SEVENBIT)) 135 ch &= 0x7f; 136 if (isalpha((unsigned char)ch)) { 137 if ((flags & RPP_FORCELOWER)) 138 ch = (char)tolower((unsigned char)ch); 139 if ((flags & RPP_FORCEUPPER)) 140 ch = (char)toupper((unsigned char)ch); 141 } 142 *p++ = ch; 143 } 144 } 145 *p = '\0'; 146 save_errno = errno; 147 if (!(term.c_lflag & ECHO)) 148 (void)write(output, "\n", 1); 149 150 /* Restore old terminal settings and signals. */ 151 if (memcmp(&term, &oterm, sizeof(term)) != 0) { 152 const int sigttou = signo[SIGTTOU]; 153 154 /* Ignore SIGTTOU generated when we are not the fg pgrp. */ 155 while (tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm) == -1 && 156 errno == EINTR && !signo[SIGTTOU]) 157 continue; 158 signo[SIGTTOU] = sigttou; 159 } 160 (void)sigaction(SIGALRM, &savealrm, NULL); 161 (void)sigaction(SIGHUP, &savehup, NULL); 162 (void)sigaction(SIGINT, &saveint, NULL); 163 (void)sigaction(SIGQUIT, &savequit, NULL); 164 (void)sigaction(SIGPIPE, &savepipe, NULL); 165 (void)sigaction(SIGTERM, &saveterm, NULL); 166 (void)sigaction(SIGTSTP, &savetstp, NULL); 167 (void)sigaction(SIGTTIN, &savettin, NULL); 168 (void)sigaction(SIGTTOU, &savettou, NULL); 169 if (input != STDIN_FILENO) 170 (void)close(input); 171 172 /* 173 * If we were interrupted by a signal, resend it to ourselves 174 * now that we have restored the signal handlers. 175 */ 176 for (i = 0; i < _NSIG; i++) { 177 if (signo[i]) { 178 kill(getpid(), i); 179 switch (i) { 180 case SIGTSTP: 181 case SIGTTIN: 182 case SIGTTOU: 183 need_restart = 1; 184 } 185 } 186 } 187 if (need_restart) 188 goto restart; 189 190 if (save_errno) 191 errno = save_errno; 192 return(nr == -1 ? NULL : buf); 193 } 194 DEF_WEAK(readpassphrase); 195 196 #if 0 197 char * 198 getpass(const char *prompt) 199 { 200 static char buf[_PASSWORD_LEN + 1]; 201 202 return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF)); 203 } 204 #endif 205 206 static void handler(int s) 207 { 208 209 signo[s] = 1; 210 } 211 #endif /* HAVE_READPASSPHRASE */ 212