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 "openbsd-compat.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 <errno.h> 35#include <string.h> 36#ifdef HAVE_UNISTD_H 37#include <unistd.h> 38#endif 39#include <paths.h> 40 41#ifndef _PATH_TTY 42# define _PATH_TTY "/dev/tty" 43#endif 44 45#ifndef TCSASOFT 46/* If we don't have TCSASOFT define it so that ORing it it below is a no-op. */ 47# define TCSASOFT 0 48#endif 49 50/* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */ 51#if !defined(_POSIX_VDISABLE) && defined(VDISABLE) 52# define _POSIX_VDISABLE VDISABLE 53#endif 54 55static volatile sig_atomic_t signo[NSIG]; 56 57static void handler(int); 58 59char * 60readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags) 61{ 62 ssize_t nr; 63 int input, output, save_errno, i, need_restart; 64 char ch, *p, *end; 65 struct termios term, oterm; 66 struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm; 67 struct sigaction savetstp, savettin, savettou, savepipe; 68 69 /* I suppose we could alloc on demand in this case (XXX). */ 70 if (bufsiz == 0) { 71 errno = EINVAL; 72 return(NULL); 73 } 74 75restart: 76 for (i = 0; i < NSIG; i++) 77 signo[i] = 0; 78 need_restart = 0; 79 /* 80 * Read and write to /dev/tty if available. If not, read from 81 * stdin and write to stderr unless a tty is required. 82 */ 83 if ((flags & RPP_STDIN) || 84 (input = output = open(_PATH_TTY, O_RDWR)) == -1) { 85 if (flags & RPP_REQUIRE_TTY) { 86 errno = ENOTTY; 87 return(NULL); 88 } 89 input = STDIN_FILENO; 90 output = STDERR_FILENO; 91 } 92 93 /* 94 * Turn off echo if possible. 95 * If we are using a tty but are not the foreground pgrp this will 96 * generate SIGTTOU, so do it *before* installing the signal handlers. 97 */ 98 if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) { 99 memcpy(&term, &oterm, sizeof(term)); 100 if (!(flags & RPP_ECHO_ON)) 101 term.c_lflag &= ~(ECHO | ECHONL); 102#ifdef VSTATUS 103 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE) 104 term.c_cc[VSTATUS] = _POSIX_VDISABLE; 105#endif 106 (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term); 107 } else { 108 memset(&term, 0, sizeof(term)); 109 term.c_lflag |= ECHO; 110 memset(&oterm, 0, sizeof(oterm)); 111 oterm.c_lflag |= ECHO; 112 } 113 114 /* 115 * Catch signals that would otherwise cause the user to end 116 * up with echo turned off in the shell. Don't worry about 117 * things like SIGXCPU and SIGVTALRM for now. 118 */ 119 sigemptyset(&sa.sa_mask); 120 sa.sa_flags = 0; /* don't restart system calls */ 121 sa.sa_handler = handler; 122 (void)sigaction(SIGALRM, &sa, &savealrm); 123 (void)sigaction(SIGHUP, &sa, &savehup); 124 (void)sigaction(SIGINT, &sa, &saveint); 125 (void)sigaction(SIGPIPE, &sa, &savepipe); 126 (void)sigaction(SIGQUIT, &sa, &savequit); 127 (void)sigaction(SIGTERM, &sa, &saveterm); 128 (void)sigaction(SIGTSTP, &sa, &savetstp); 129 (void)sigaction(SIGTTIN, &sa, &savettin); 130 (void)sigaction(SIGTTOU, &sa, &savettou); 131 132 if (!(flags & RPP_STDIN)) 133 (void)write(output, prompt, strlen(prompt)); 134 end = buf + bufsiz - 1; 135 p = buf; 136 while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') { 137 if (p < end) { 138 if ((flags & RPP_SEVENBIT)) 139 ch &= 0x7f; 140 if (isalpha((unsigned char)ch)) { 141 if ((flags & RPP_FORCELOWER)) 142 ch = (char)tolower((unsigned char)ch); 143 if ((flags & RPP_FORCEUPPER)) 144 ch = (char)toupper((unsigned char)ch); 145 } 146 *p++ = ch; 147 } 148 } 149 *p = '\0'; 150 save_errno = errno; 151 if (!(term.c_lflag & ECHO)) 152 (void)write(output, "\n", 1); 153 154 /* Restore old terminal settings and signals. */ 155 if (memcmp(&term, &oterm, sizeof(term)) != 0) { 156 const int sigttou = signo[SIGTTOU]; 157 158 /* Ignore SIGTTOU generated when we are not the fg pgrp. */ 159 while (tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm) == -1 && 160 errno == EINTR && !signo[SIGTTOU]) 161 continue; 162 signo[SIGTTOU] = sigttou; 163 } 164 (void)sigaction(SIGALRM, &savealrm, NULL); 165 (void)sigaction(SIGHUP, &savehup, NULL); 166 (void)sigaction(SIGINT, &saveint, NULL); 167 (void)sigaction(SIGQUIT, &savequit, NULL); 168 (void)sigaction(SIGPIPE, &savepipe, NULL); 169 (void)sigaction(SIGTERM, &saveterm, NULL); 170 (void)sigaction(SIGTSTP, &savetstp, NULL); 171 (void)sigaction(SIGTTIN, &savettin, NULL); 172 (void)sigaction(SIGTTOU, &savettou, NULL); 173 if (input != STDIN_FILENO) 174 (void)close(input); 175 176 /* 177 * If we were interrupted by a signal, resend it to ourselves 178 * now that we have restored the signal handlers. 179 */ 180 for (i = 0; i < NSIG; i++) { 181 if (signo[i]) { 182 kill(getpid(), i); 183 switch (i) { 184 case SIGTSTP: 185 case SIGTTIN: 186 case SIGTTOU: 187 need_restart = 1; 188 } 189 } 190 } 191 if (need_restart) 192 goto restart; 193 194 if (save_errno) 195 errno = save_errno; 196 return(nr == -1 ? NULL : buf); 197} 198 199#if 0 200char * 201getpass(const char *prompt) 202{ 203 static char buf[_PASSWORD_LEN + 1]; 204 205 return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF)); 206} 207#endif 208 209static void handler(int s) 210{ 211 212 signo[s] = 1; 213} 214#endif /* HAVE_READPASSPHRASE */ 215