1 /* $OpenBSD: readpassphrase.c,v 1.22 2010/01/13 10:20:54 dtucker Exp $ */
2
3 /*
4 * Copyright (c) 2000-2002, 2007 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 /* OPENBSD ORIGINAL: lib/libc/gen/readpassphrase.c */
24
25 #include "includes.h"
26
27 #ifndef HAVE_READPASSPHRASE
28
29 #include <termios.h>
30 #include <signal.h>
31 #include <ctype.h>
32 #include <fcntl.h>
33 #include <errno.h>
34 #include <string.h>
35 #include <unistd.h>
36
37 #include "readpassphrase.h"
38
39 #ifdef TCSASOFT
40 # define _T_FLUSH (TCSAFLUSH|TCSASOFT)
41 #else
42 # define _T_FLUSH (TCSAFLUSH)
43 #endif
44
45 /* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
46 #if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
47 # define _POSIX_VDISABLE VDISABLE
48 #endif
49
50 static volatile sig_atomic_t signo[_NSIG];
51
52 static void handler(int);
53
54 char *
readpassphrase(const char * prompt,char * buf,size_t bufsiz,int flags)55 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
56 {
57 ssize_t nr;
58 int input, output, save_errno, i, need_restart;
59 char ch, *p, *end;
60 struct termios term, oterm;
61 struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
62 struct sigaction savetstp, savettin, savettou, savepipe;
63
64 /* I suppose we could alloc on demand in this case (XXX). */
65 if (bufsiz == 0) {
66 errno = EINVAL;
67 return(NULL);
68 }
69
70 restart:
71 for (i = 0; i < _NSIG; i++)
72 signo[i] = 0;
73 nr = -1;
74 save_errno = 0;
75 need_restart = 0;
76 /*
77 * Read and write to /dev/tty if available. If not, read from
78 * stdin and write to stderr unless a tty is required.
79 */
80 if ((flags & RPP_STDIN) ||
81 (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
82 if (flags & RPP_REQUIRE_TTY) {
83 errno = ENOTTY;
84 return(NULL);
85 }
86 input = STDIN_FILENO;
87 output = STDERR_FILENO;
88 }
89
90 /*
91 * Catch signals that would otherwise cause the user to end
92 * up with echo turned off in the shell. Don't worry about
93 * things like SIGXCPU and SIGVTALRM for now.
94 */
95 sigemptyset(&sa.sa_mask);
96 sa.sa_flags = 0; /* don't restart system calls */
97 sa.sa_handler = handler;
98 (void)sigaction(SIGALRM, &sa, &savealrm);
99 (void)sigaction(SIGHUP, &sa, &savehup);
100 (void)sigaction(SIGINT, &sa, &saveint);
101 (void)sigaction(SIGPIPE, &sa, &savepipe);
102 (void)sigaction(SIGQUIT, &sa, &savequit);
103 (void)sigaction(SIGTERM, &sa, &saveterm);
104 (void)sigaction(SIGTSTP, &sa, &savetstp);
105 (void)sigaction(SIGTTIN, &sa, &savettin);
106 (void)sigaction(SIGTTOU, &sa, &savettou);
107
108 /* Turn off echo if possible. */
109 if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
110 memcpy(&term, &oterm, sizeof(term));
111 if (!(flags & RPP_ECHO_ON))
112 term.c_lflag &= ~(ECHO | ECHONL);
113 #ifdef VSTATUS
114 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
115 term.c_cc[VSTATUS] = _POSIX_VDISABLE;
116 #endif
117 (void)tcsetattr(input, _T_FLUSH, &term);
118 } else {
119 memset(&term, 0, sizeof(term));
120 term.c_lflag |= ECHO;
121 memset(&oterm, 0, sizeof(oterm));
122 oterm.c_lflag |= ECHO;
123 }
124
125 /* No I/O if we are already backgrounded. */
126 if (signo[SIGTTOU] != 1 && signo[SIGTTIN] != 1) {
127 if (!(flags & RPP_STDIN))
128 (void)write(output, prompt, strlen(prompt));
129 end = buf + bufsiz - 1;
130 p = buf;
131 while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
132 if (p < end) {
133 if ((flags & RPP_SEVENBIT))
134 ch &= 0x7f;
135 if (isalpha(ch)) {
136 if ((flags & RPP_FORCELOWER))
137 ch = (char)tolower(ch);
138 if ((flags & RPP_FORCEUPPER))
139 ch = (char)toupper(ch);
140 }
141 *p++ = ch;
142 }
143 }
144 *p = '\0';
145 save_errno = errno;
146 if (!(term.c_lflag & ECHO))
147 (void)write(output, "\n", 1);
148 }
149
150 /* Restore old terminal settings and signals. */
151 if (memcmp(&term, &oterm, sizeof(term)) != 0) {
152 while (tcsetattr(input, _T_FLUSH, &oterm) == -1 &&
153 errno == EINTR)
154 continue;
155 }
156 (void)sigaction(SIGALRM, &savealrm, NULL);
157 (void)sigaction(SIGHUP, &savehup, NULL);
158 (void)sigaction(SIGINT, &saveint, NULL);
159 (void)sigaction(SIGQUIT, &savequit, NULL);
160 (void)sigaction(SIGPIPE, &savepipe, NULL);
161 (void)sigaction(SIGTERM, &saveterm, NULL);
162 (void)sigaction(SIGTSTP, &savetstp, NULL);
163 (void)sigaction(SIGTTIN, &savettin, NULL);
164 (void)sigaction(SIGTTOU, &savettou, NULL);
165 if (input != STDIN_FILENO)
166 (void)close(input);
167
168 /*
169 * If we were interrupted by a signal, resend it to ourselves
170 * now that we have restored the signal handlers.
171 */
172 for (i = 0; i < _NSIG; i++) {
173 if (signo[i]) {
174 kill(getpid(), i);
175 switch (i) {
176 case SIGTSTP:
177 case SIGTTIN:
178 case SIGTTOU:
179 need_restart = 1;
180 }
181 }
182 }
183 if (need_restart)
184 goto restart;
185
186 if (save_errno)
187 errno = save_errno;
188 return(nr == -1 ? NULL : buf);
189 }
190
191 #if 0
192 char *
193 getpass(const char *prompt)
194 {
195 static char buf[_PASSWORD_LEN + 1];
196
197 return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
198 }
199 #endif
200
handler(int s)201 static void handler(int s)
202 {
203
204 signo[s] = 1;
205 }
206 #endif /* HAVE_READPASSPHRASE */
207