xref: /freebsd/contrib/libarchive/libarchive_fe/passphrase.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
1 /*-
2  * Copyright (c) 2014 Michihiro NAKAJIMA
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 /*	$OpenBSD: readpassphrase.c,v 1.27 2019/01/25 00:19:25 millert Exp $	*/
27 
28 /*
29  * Copyright (c) 2000-2002, 2007, 2010
30  * 	Todd C. Miller <millert@openbsd.org>
31  *
32  * Permission to use, copy, modify, and distribute this software for any
33  * purpose with or without fee is hereby granted, provided that the above
34  * copyright notice and this permission notice appear in all copies.
35  *
36  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
37  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
38  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
39  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
40  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
41  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
42  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
43  *
44  * Sponsored in part by the Defense Advanced Research Projects
45  * Agency (DARPA) and Air Force Research Laboratory, Air Force
46  * Materiel Command, USAF, under agreement number F39502-99-1-0512.
47  */
48 
49 /* OPENBSD ORIGINAL: lib/libc/gen/readpassphrase.c */
50 
51 
52 #include "lafe_platform.h"
53 #include <errno.h>
54 #ifdef HAVE_STDLIB_H
55 #include <stdlib.h>
56 #endif
57 #ifdef HAVE_UNISTD_H
58 #include <unistd.h>
59 #endif
60 #ifdef HAVE_READPASSPHRASE_H
61 #include <readpassphrase.h>
62 #endif
63 
64 #include "err.h"
65 #include "passphrase.h"
66 
67 #ifndef HAVE_READPASSPHRASE
68 
69 #define RPP_ECHO_OFF    0x00		/* Turn off echo (default). */
70 #define RPP_ECHO_ON     0x01		/* Leave echo on. */
71 #define RPP_REQUIRE_TTY 0x02		/* Fail if there is no tty. */
72 #define RPP_FORCELOWER  0x04		/* Force input to lower case. */
73 #define RPP_FORCEUPPER  0x08		/* Force input to upper case. */
74 #define RPP_SEVENBIT    0x10		/* Strip the high bit from input. */
75 #define RPP_STDIN       0x20		/* Read from stdin, not /dev/tty */
76 
77 
78 #if defined(_WIN32) && !defined(__CYGWIN__)
79 #include <string.h>
80 #include <windows.h>
81 
82 static char *
83 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
84 {
85 	HANDLE hStdin, hStdout;
86 	DWORD mode, rbytes;
87 	BOOL success;
88 
89 	(void)flags;
90 
91 	hStdin = GetStdHandle(STD_INPUT_HANDLE);
92 	if (hStdin == INVALID_HANDLE_VALUE)
93 		return (NULL);
94 	hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
95 	if (hStdout == INVALID_HANDLE_VALUE)
96 		return (NULL);
97 
98 	success = GetConsoleMode(hStdin, &mode);
99 	if (!success)
100 		return (NULL);
101 	mode &= ~ENABLE_ECHO_INPUT;
102 	mode |= ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT;
103 	success = SetConsoleMode(hStdin, mode);
104 	if (!success)
105 		return (NULL);
106 
107 	success = WriteFile(hStdout, prompt, (DWORD)strlen(prompt),
108 		NULL, NULL);
109 	if (!success)
110 		return (NULL);
111 	success = ReadFile(hStdin, buf, (DWORD)bufsiz - 1, &rbytes, NULL);
112 	if (!success)
113 		return (NULL);
114 	WriteFile(hStdout, "\r\n", 2, NULL, NULL);
115 	buf[rbytes] = '\0';
116 	/* Remove trailing carriage return(s). */
117 	buf[strcspn(buf, "\r\n")] = '\0';
118 
119 	return (buf);
120 }
121 
122 #else /* _WIN32 && !__CYGWIN__ */
123 
124 #include <assert.h>
125 #include <ctype.h>
126 #include <fcntl.h>
127 #ifdef HAVE_PATHS_H
128 #include <paths.h>
129 #endif
130 #include <signal.h>
131 #include <string.h>
132 #include <termios.h>
133 #include <unistd.h>
134 
135 #ifndef _PATH_TTY
136 #define _PATH_TTY "/dev/tty"
137 #endif
138 
139 #ifdef TCSASOFT
140 # define _T_FLUSH	(TCSAFLUSH|TCSASOFT)
141 #else
142 # define _T_FLUSH	(TCSAFLUSH)
143 #endif
144 
145 /* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
146 #if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
147 #  define _POSIX_VDISABLE       VDISABLE
148 #endif
149 
150 #define M(a,b) (a > b ? a : b)
151 #define MAX_SIGNO M(M(M(SIGALRM, SIGHUP), \
152                       M(SIGINT, SIGPIPE)), \
153                     M(M(SIGQUIT, SIGTERM), \
154                       M(M(SIGTSTP, SIGTTIN), SIGTTOU)))
155 
156 static volatile sig_atomic_t signo[MAX_SIGNO + 1];
157 
158 static void
159 handler(int s)
160 {
161 	assert(s <= MAX_SIGNO);
162 	signo[s] = 1;
163 }
164 
165 static char *
166 readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
167 {
168 	ssize_t nr;
169 	int input, output, save_errno, i, need_restart;
170 	char ch, *p, *end;
171 	struct termios term, oterm;
172 #ifdef HAVE_SIGACTION
173 	struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
174 	struct sigaction savetstp, savettin, savettou, savepipe;
175 #endif
176 
177 	/* I suppose we could alloc on demand in this case (XXX). */
178 	if (bufsiz == 0) {
179 		errno = EINVAL;
180 		return(NULL);
181 	}
182 
183 restart:
184 	for (i = 0; i <= MAX_SIGNO; i++)
185 		signo[i] = 0;
186 	nr = -1;
187 	save_errno = 0;
188 	need_restart = 0;
189 	/*
190 	 * Read and write to /dev/tty if available.  If not, read from
191 	 * stdin and write to stderr unless a tty is required.
192 	 */
193 	if ((flags & RPP_STDIN) ||
194 	    (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
195 		if (flags & RPP_REQUIRE_TTY) {
196 			errno = ENOTTY;
197 			return(NULL);
198 		}
199 		input = STDIN_FILENO;
200 		output = STDERR_FILENO;
201 	}
202 
203 	/*
204 	 * Turn off echo if possible.
205 	 * If we are using a tty but are not the foreground pgrp this will
206 	 * generate SIGTTOU, so do it *before* installing the signal handlers.
207 	 */
208 	if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
209 		memcpy(&term, &oterm, sizeof(term));
210 		if (!(flags & RPP_ECHO_ON))
211 			term.c_lflag &= ~(ECHO | ECHONL);
212 #ifdef VSTATUS
213 		if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
214 			term.c_cc[VSTATUS] = _POSIX_VDISABLE;
215 #endif
216 		(void)tcsetattr(input, _T_FLUSH, &term);
217 	} else {
218 		memset(&term, 0, sizeof(term));
219 		term.c_lflag |= ECHO;
220 		memset(&oterm, 0, sizeof(oterm));
221 		oterm.c_lflag |= ECHO;
222 	}
223 
224 #ifdef HAVE_SIGACTION
225 	/*
226 	 * Catch signals that would otherwise cause the user to end
227 	 * up with echo turned off in the shell.  Don't worry about
228 	 * things like SIGXCPU and SIGVTALRM for now.
229 	 */
230 	sigemptyset(&sa.sa_mask);
231 	sa.sa_flags = 0;		/* don't restart system calls */
232 	sa.sa_handler = handler;
233 	/* Keep this list in sync with MAX_SIGNO! */
234 	(void)sigaction(SIGALRM, &sa, &savealrm);
235 	(void)sigaction(SIGHUP, &sa, &savehup);
236 	(void)sigaction(SIGINT, &sa, &saveint);
237 	(void)sigaction(SIGPIPE, &sa, &savepipe);
238 	(void)sigaction(SIGQUIT, &sa, &savequit);
239 	(void)sigaction(SIGTERM, &sa, &saveterm);
240 	(void)sigaction(SIGTSTP, &sa, &savetstp);
241 	(void)sigaction(SIGTTIN, &sa, &savettin);
242 	(void)sigaction(SIGTTOU, &sa, &savettou);
243 #endif
244 
245 	if (!(flags & RPP_STDIN)) {
246 		int r = write(output, prompt, strlen(prompt));
247 		(void)r;
248 	}
249 	end = buf + bufsiz - 1;
250 	p = buf;
251 	while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
252 		if (p < end) {
253 			if ((flags & RPP_SEVENBIT))
254 				ch &= 0x7f;
255 			if (isalpha((unsigned char)ch)) {
256 				if ((flags & RPP_FORCELOWER))
257 					ch = (char)tolower((unsigned char)ch);
258 				if ((flags & RPP_FORCEUPPER))
259 					ch = (char)toupper((unsigned char)ch);
260 			}
261 			*p++ = ch;
262 		}
263 	}
264 	*p = '\0';
265 	save_errno = errno;
266 	if (!(term.c_lflag & ECHO)) {
267 		int r = write(output, "\n", 1);
268 		(void)r;
269 	}
270 
271 	/* Restore old terminal settings and signals. */
272 	if (memcmp(&term, &oterm, sizeof(term)) != 0) {
273 		const int sigttou = signo[SIGTTOU];
274 
275 		/* Ignore SIGTTOU generated when we are not the fg pgrp. */
276 		while (tcsetattr(input, _T_FLUSH, &oterm) == -1 &&
277 		    errno == EINTR && !signo[SIGTTOU])
278 			continue;
279 		signo[SIGTTOU] = sigttou;
280 	}
281 #ifdef HAVE_SIGACTION
282 	(void)sigaction(SIGALRM, &savealrm, NULL);
283 	(void)sigaction(SIGHUP, &savehup, NULL);
284 	(void)sigaction(SIGINT, &saveint, NULL);
285 	(void)sigaction(SIGQUIT, &savequit, NULL);
286 	(void)sigaction(SIGPIPE, &savepipe, NULL);
287 	(void)sigaction(SIGTERM, &saveterm, NULL);
288 	(void)sigaction(SIGTSTP, &savetstp, NULL);
289 	(void)sigaction(SIGTTIN, &savettin, NULL);
290 	(void)sigaction(SIGTTOU, &savettou, NULL);
291 #endif
292 	if (input != STDIN_FILENO)
293 		(void)close(input);
294 
295 	/*
296 	 * If we were interrupted by a signal, resend it to ourselves
297 	 * now that we have restored the signal handlers.
298 	 */
299 	for (i = 0; i <= MAX_SIGNO; i++) {
300 		if (signo[i]) {
301 			kill(getpid(), i);
302 			switch (i) {
303 			case SIGTSTP:
304 			case SIGTTIN:
305 			case SIGTTOU:
306 				need_restart = 1;
307 			}
308 		}
309 	}
310 	if (need_restart)
311 		goto restart;
312 
313 	if (save_errno)
314 		errno = save_errno;
315 	return(nr == -1 ? NULL : buf);
316 }
317 #endif /* _WIN32 && !__CYGWIN__ */
318 #endif /* HAVE_READPASSPHRASE */
319 
320 char *
321 lafe_readpassphrase(const char *prompt, char *buf, size_t bufsiz)
322 {
323 	char *p;
324 
325 	p = readpassphrase(prompt, buf, bufsiz, RPP_ECHO_OFF);
326 	if (p == NULL) {
327 		switch (errno) {
328 		case EINTR:
329 			break;
330 		default:
331 			lafe_errc(1, errno, "Couldn't read passphrase");
332 			/* NOTREACHED */
333 		}
334 	}
335 	return (p);
336 }
337 
338