treadpassphrase.c - ratox - FIFO based tox client
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treadpassphrase.c (5310B)
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1 /* $OpenBSD: readpassphrase.c,v 1.25 2015/09/14 10:45:27 guenther 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 #include <ctype.h>
25 #include <errno.h>
26 #include <fcntl.h>
27 #include <paths.h>
28 #include <pwd.h>
29 #include <signal.h>
30 #include <string.h>
31 #include <termios.h>
32 #include <unistd.h>
33
34 #include "readpassphrase.h"
35
36 #ifdef TCSASOFT
37 #define _T_FLUSH (TCSAFLUSH|TCSASOFT)
38 #else
39 #define _T_FLUSH (TCSAFLUSH)
40 #endif
41
42 static volatile sig_atomic_t signo[_NSIG];
43
44 static void handler(int);
45
46 char *
47 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
48 {
49 ssize_t nr;
50 int input, output, save_errno, i, need_restart;
51 char ch, *p, *end;
52 struct termios term, oterm;
53 struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
54 struct sigaction savetstp, savettin, savettou, savepipe;
55
56 /* I suppose we could alloc on demand in this case (XXX). */
57 if (bufsiz == 0) {
58 errno = EINVAL;
59 return(NULL);
60 }
61
62 restart:
63 for (i = 0; i < _NSIG; i++)
64 signo[i] = 0;
65 nr = -1;
66 save_errno = 0;
67 need_restart = 0;
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 ((flags & RPP_STDIN) ||
73 (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
74 if (flags & RPP_REQUIRE_TTY) {
75 errno = ENOTTY;
76 return(NULL);
77 }
78 input = STDIN_FILENO;
79 output = STDERR_FILENO;
80 }
81
82 /*
83 * Turn off echo if possible.
84 * If we are using a tty but are not the foreground pgrp this will
85 * generate SIGTTOU, so do it *before* installing the signal handlers.
86 */
87 if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
88 memcpy(&term, &oterm, sizeof(term));
89 if (!(flags & RPP_ECHO_ON))
90 term.c_lflag &= ~(ECHO | ECHONL);
91 #ifdef VSTATUS
92 if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
93 term.c_cc[VSTATUS] = _POSIX_VDISABLE;
94 #endif
95 (void)tcsetattr(input, _T_FLUSH, &term);
96 } else {
97 memset(&term, 0, sizeof(term));
98 term.c_lflag |= ECHO;
99 memset(&oterm, 0, sizeof(oterm));
100 oterm.c_lflag |= ECHO;
101 }
102
103 /*
104 * Catch signals that would otherwise cause the user to end
105 * up with echo turned off in the shell. Don't worry about
106 * things like SIGXCPU and SIGVTALRM for now.
107 */
108 sigemptyset(&sa.sa_mask);
109 sa.sa_flags = 0; /* don't restart system calls */
110 sa.sa_handler = handler;
111 (void)sigaction(SIGALRM, &sa, &savealrm);
112 (void)sigaction(SIGHUP, &sa, &savehup);
113 (void)sigaction(SIGINT, &sa, &saveint);
114 (void)sigaction(SIGPIPE, &sa, &savepipe);
115 (void)sigaction(SIGQUIT, &sa, &savequit);
116 (void)sigaction(SIGTERM, &sa, &saveterm);
117 (void)sigaction(SIGTSTP, &sa, &savetstp);
118 (void)sigaction(SIGTTIN, &sa, &savettin);
119 (void)sigaction(SIGTTOU, &sa, &savettou);
120
121 if (!(flags & RPP_STDIN))
122 (void)write(output, prompt, strlen(prompt));
123 end = buf + bufsiz - 1;
124 p = buf;
125 while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
126 if (p < end) {
127 if ((flags & RPP_SEVENBIT))
128 ch &= 0x7f;
129 if (isalpha((unsigned char)ch)) {
130 if ((flags & RPP_FORCELOWER))
131 ch = (char)tolower((unsigned char)ch);
132 if ((flags & RPP_FORCEUPPER))
133 ch = (char)toupper((unsigned char)ch);
134 }
135 *p++ = ch;
136 }
137 }
138 *p = '\0';
139 save_errno = errno;
140 if (!(term.c_lflag & ECHO))
141 (void)write(output, "\n", 1);
142
143 /* Restore old terminal settings and signals. */
144 if (memcmp(&term, &oterm, sizeof(term)) != 0) {
145 while (tcsetattr(input, _T_FLUSH, &oterm) == -1 &&
146 errno == EINTR && !signo[SIGTTOU])
147 continue;
148 }
149 (void)sigaction(SIGALRM, &savealrm, NULL);
150 (void)sigaction(SIGHUP, &savehup, NULL);
151 (void)sigaction(SIGINT, &saveint, NULL);
152 (void)sigaction(SIGQUIT, &savequit, NULL);
153 (void)sigaction(SIGPIPE, &savepipe, NULL);
154 (void)sigaction(SIGTERM, &saveterm, NULL);
155 (void)sigaction(SIGTSTP, &savetstp, NULL);
156 (void)sigaction(SIGTTIN, &savettin, NULL);
157 (void)sigaction(SIGTTOU, &savettou, NULL);
158 if (input != STDIN_FILENO)
159 (void)close(input);
160
161 /*
162 * If we were interrupted by a signal, resend it to ourselves
163 * now that we have restored the signal handlers.
164 */
165 for (i = 0; i < _NSIG; i++) {
166 if (signo[i]) {
167 kill(getpid(), i);
168 switch (i) {
169 case SIGTSTP:
170 case SIGTTIN:
171 case SIGTTOU:
172 need_restart = 1;
173 }
174 }
175 }
176 if (need_restart)
177 goto restart;
178
179 if (save_errno)
180 errno = save_errno;
181 return(nr == -1 ? NULL : buf);
182 }
183
184 static void handler(int s)
185 {
186 signo[s] = 1;
187 }