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 * $OpenBSD: readpassphrase.c,v 1.12 2001/12/15 05:41:00 millert Exp $ 30 * $FreeBSD: src/lib/libc/gen/readpassphrase.c,v 1.6.2.2 2002/06/30 13:54:26 des Exp $ 31 * $DragonFly: src/lib/libc/gen/readpassphrase.c,v 1.4 2005/11/13 00:07:42 swildner Exp $ 32 */ 33 34 #include "namespace.h" 35 #include <ctype.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #include <paths.h> 39 #include <pwd.h> 40 #include <signal.h> 41 #include <string.h> 42 #include <termios.h> 43 #include <unistd.h> 44 #include <readpassphrase.h> 45 #include "un-namespace.h" 46 47 static volatile sig_atomic_t signo; 48 49 static void handler(int); 50 51 char * 52 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags) 53 { 54 ssize_t nr; 55 int input, output, save_errno; 56 char ch, *p, *end; 57 struct termios term, oterm; 58 struct sigaction sa, saveint, savehup, savequit, saveterm; 59 struct sigaction savetstp, savettin, savettou; 60 61 /* I suppose we could alloc on demand in this case (XXX). */ 62 if (bufsiz == 0) { 63 errno = EINVAL; 64 return(NULL); 65 } 66 67 restart: 68 /* 69 * Read and write to /dev/tty if available. If not, read from 70 * stdin and write to stderr unless a tty is required. 71 */ 72 if ((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 SIGALRM and SIGPIPE for now. 85 */ 86 sigemptyset(&sa.sa_mask); 87 sa.sa_flags = 0; /* don't restart system calls */ 88 sa.sa_handler = handler; 89 _sigaction(SIGINT, &sa, &saveint); 90 _sigaction(SIGHUP, &sa, &savehup); 91 _sigaction(SIGQUIT, &sa, &savequit); 92 _sigaction(SIGTERM, &sa, &saveterm); 93 _sigaction(SIGTSTP, &sa, &savetstp); 94 _sigaction(SIGTTIN, &sa, &savettin); 95 _sigaction(SIGTTOU, &sa, &savettou); 96 97 /* Turn off echo if possible. */ 98 if (tcgetattr(input, &oterm) == 0) { 99 memcpy(&term, &oterm, sizeof(term)); 100 if (!(flags & RPP_ECHO_ON)) 101 term.c_lflag &= ~(ECHO | ECHONL); 102 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE) 103 term.c_cc[VSTATUS] = _POSIX_VDISABLE; 104 tcsetattr(input, TCSAFLUSH|TCSASOFT, &term); 105 } else { 106 memset(&term, 0, sizeof(term)); 107 memset(&oterm, 0, sizeof(oterm)); 108 } 109 110 _write(output, prompt, strlen(prompt)); 111 end = buf + bufsiz - 1; 112 for (p = buf; (nr = _read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r';) { 113 if (p < end) { 114 if ((flags & RPP_SEVENBIT)) 115 ch &= 0x7f; 116 if (isalpha(ch)) { 117 if ((flags & RPP_FORCELOWER)) 118 ch = tolower(ch); 119 if ((flags & RPP_FORCEUPPER)) 120 ch = toupper(ch); 121 } 122 *p++ = ch; 123 } 124 } 125 *p = '\0'; 126 save_errno = errno; 127 if (!(term.c_lflag & ECHO)) 128 _write(output, "\n", 1); 129 130 /* Restore old terminal settings and signals. */ 131 if (memcmp(&term, &oterm, sizeof(term)) != 0) 132 tcsetattr(input, TCSANOW|TCSASOFT, &oterm); 133 _sigaction(SIGINT, &saveint, NULL); 134 _sigaction(SIGHUP, &savehup, NULL); 135 _sigaction(SIGQUIT, &savequit, NULL); 136 _sigaction(SIGTERM, &saveterm, NULL); 137 _sigaction(SIGTSTP, &savetstp, NULL); 138 _sigaction(SIGTTIN, &savettin, NULL); 139 _sigaction(SIGTTOU, &savettou, NULL); 140 if (input != STDIN_FILENO) 141 _close(input); 142 143 /* 144 * If we were interrupted by a signal, resend it to ourselves 145 * now that we have restored the signal handlers. 146 */ 147 if (signo) { 148 kill(getpid(), signo); 149 switch (signo) { 150 case SIGTSTP: 151 case SIGTTIN: 152 case SIGTTOU: 153 signo = 0; 154 goto restart; 155 } 156 } 157 158 errno = save_errno; 159 return(nr == -1 ? NULL : buf); 160 } 161 162 char * 163 getpass(const char *prompt) 164 { 165 static char buf[_PASSWORD_LEN + 1]; 166 167 if (readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF) == NULL) 168 buf[0] = '\0'; 169 return(buf); 170 } 171 172 static void 173 handler(int s) 174 { 175 signo = s; 176 } 177