xref: /netbsd-src/crypto/external/bsd/openssh/dist/readpassphrase.c (revision d91f98a8715141154279122ae81737cb65179572)
1 /*	$NetBSD: readpassphrase.c,v 1.9 2019/01/27 02:08:33 pgoyette Exp $	*/
2 /*
3  * Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
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  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
18  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
19  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
20  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
25  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
26  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "includes.h"
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static const char rcsid[] = "$OpenBSD: readpassphrase.c,v 1.7 2001/08/07 19:34:11 millert Exp $";
32 #endif /* LIBC_SCCS and not lint */
33 __RCSID("$NetBSD: readpassphrase.c,v 1.9 2019/01/27 02:08:33 pgoyette Exp $");
34 
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 
46 char *
readpassphrase(prompt,buf,bufsiz,flags)47 readpassphrase(prompt, buf, bufsiz, flags)
48 	const char *prompt;
49 	char *buf;
50 	size_t bufsiz;
51 	int flags;
52 {
53 #ifdef GETPASS_ECHO
54 	int gflags = GETPASS_ECHO_NL;
55 
56 	if (flags & RPP_ECHO_ON)
57 		gflags |= GETPASS_ECHO;
58 	if (flags & RPP_REQUIRE_TTY)
59 		gflags |= GETPASS_NEED_TTY;
60 	if (flags & RPP_FORCELOWER)
61 		gflags |= GETPASS_FORCE_LOWER;
62 	if (flags & RPP_FORCEUPPER)
63 		gflags |= GETPASS_FORCE_UPPER;
64 	if (flags & RPP_SEVENBIT)
65 		gflags |= GETPASS_7BIT;
66 
67 	return getpassfd(prompt, buf, bufsiz, NULL, gflags, 0);
68 #else
69 	struct termios term, oterm;
70 	char ch, *p, *end;
71 	int input, output;
72 	sigset_t oset, nset;
73 
74 	/* I suppose we could alloc on demand in this case (XXX). */
75 	if (bufsiz == 0) {
76 		errno = EINVAL;
77 		return(NULL);
78 	}
79 
80 	/*
81 	 * Read and write to /dev/tty if available.  If not, read from
82 	 * stdin and write to stderr unless a tty is required.
83 	 */
84 	if ((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 	 * We block SIGINT and SIGTSTP so the terminal is not left
95 	 * in an inconsistent state (ie: no echo).  It would probably
96 	 * be better to simply catch these though.
97 	 */
98 	sigemptyset(&nset);
99 	sigaddset(&nset, SIGINT);
100 	sigaddset(&nset, SIGTSTP);
101 	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
102 
103 	/* Turn off echo if possible. */
104 	if (tcgetattr(input, &oterm) == 0) {
105 		memcpy(&term, &oterm, sizeof(term));
106 		if (!(flags & RPP_ECHO_ON) && (term.c_lflag & ECHO))
107 			term.c_lflag &= ~ECHO;
108 		if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
109 			term.c_cc[VSTATUS] = _POSIX_VDISABLE;
110 		(void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
111 	} else {
112 		memset(&term, 0, sizeof(term));
113 		memset(&oterm, 0, sizeof(oterm));
114 	}
115 
116 	(void)write(output, prompt, strlen(prompt));
117 	end = buf + bufsiz - 1;
118 	for (p = buf; read(input, &ch, 1) == 1 && ch != '\n' && ch != '\r';) {
119 		if (p < end) {
120 			if ((flags & RPP_SEVENBIT))
121 				ch &= 0x7f;
122 			if (isalpha((unsigned char)ch)) {
123 				if ((flags & RPP_FORCELOWER))
124 					ch = tolower((unsigned char)ch);
125 				if ((flags & RPP_FORCEUPPER))
126 					ch = toupper((unsigned char)ch);
127 			}
128 			*p++ = ch;
129 		}
130 	}
131 	*p = '\0';
132 	if (!(term.c_lflag & ECHO))
133 		(void)write(output, "\n", 1);
134 
135 	/* Restore old terminal settings and signal mask. */
136 	if (memcmp(&term, &oterm, sizeof(term)) != 0)
137 		(void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm);
138 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
139 	if (input != STDIN_FILENO)
140 		(void)close(input);
141 	return(buf);
142 #endif
143 }
144 
145 char *
getpass(prompt)146 getpass(prompt)
147         const char *prompt;
148 {
149 	static char buf[_PASSWORD_LEN + 1];
150 
151 	return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
152 }
153