1/*	$OpenBSD: login_reject.c,v 1.18 2021/10/23 19:08:48 mestre Exp $	*/
2
3/*-
4 * Copyright (c) 1995 Berkeley Software Design, Inc. 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. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *      This product includes software developed by Berkeley Software Design,
17 *      Inc.
18 * 4. The name of Berkeley Software Design, Inc.  may not be used to endorse
19 *    or promote products derived from this software without specific prior
20 *    written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN, INC. ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN, INC. BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *	BSDI $From: login_reject.c,v 1.5 1996/08/22 20:43:11 prb Exp $
35 */
36
37#include <sys/resource.h>
38
39#include <login_cap.h>
40#include <readpassphrase.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <syslog.h>
45#include <unistd.h>
46
47int
48main(int argc, char *argv[])
49{
50	struct rlimit rl;
51	FILE *back;
52	char passbuf[1];
53	int mode = 0, c;
54
55	rl.rlim_cur = 0;
56	rl.rlim_max = 0;
57	(void)setrlimit(RLIMIT_CORE, &rl);
58
59	(void)setpriority(PRIO_PROCESS, 0, 0);
60
61	if (pledge("stdio rpath tty", NULL) == -1) {
62		syslog(LOG_AUTH|LOG_ERR, "pledge: %m");
63		exit(1);
64	}
65
66	openlog("login", LOG_ODELAY, LOG_AUTH);
67
68	while ((c = getopt(argc, argv, "v:s:")) != -1)
69		switch (c) {
70		case 'v':
71			break;
72		case 's':	/* service */
73			if (strcmp(optarg, "login") == 0)
74				mode = 0;
75			else if (strcmp(optarg, "challenge") == 0)
76				mode = 1;
77			else if (strcmp(optarg, "response") == 0)
78				mode = 2;
79			else {
80				syslog(LOG_ERR, "%s: invalid service", optarg);
81				exit(1);
82			}
83			break;
84		default:
85			syslog(LOG_ERR, "usage error");
86			exit(1);
87		}
88
89	switch (argc - optind) {
90	case 2:
91	case 1:
92		break;
93	default:
94		syslog(LOG_ERR, "usage error");
95		exit(1);
96	}
97
98	if (!(back = fdopen(3, "r+")))  {
99		syslog(LOG_ERR, "reopening back channel: %m");
100		exit(1);
101	}
102	if (mode == 1) {
103		fprintf(back, BI_SILENT "\n");
104		exit(0);
105	}
106
107	if (mode == 2) {
108		mode = 0;
109		c = -1;
110		while (read(3, passbuf, 1) == 1) {
111			if (passbuf[0] == '\0' && ++mode == 2)
112				break;
113		}
114		if (mode < 2) {
115			syslog(LOG_ERR, "protocol error on back channel");
116			exit(1);
117		}
118	} else
119		readpassphrase("Password:", passbuf, sizeof(passbuf), 0);
120
121	crypt_checkpass("password", NULL);
122	explicit_bzero(passbuf, sizeof(passbuf));
123
124	fprintf(back, BI_REJECT "\n");
125	exit(1);
126}
127