xref: /openbsd-src/libexec/login_token/login_token.c (revision 07817e4bdc8b6868189ab279749fa0d1c77e97fb)
1 /*	$OpenBSD: login_token.c,v 1.17 2021/01/02 20:32:20 millert Exp $	*/
2 
3 /*-
4  * Copyright (c) 1995, 1996 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_token.c,v 1.2 1996/09/04 05:33:05 prb Exp $
35  */
36 
37 #include <sys/types.h>
38 #include <sys/time.h>
39 #include <sys/resource.h>
40 
41 #include <err.h>
42 #include <readpassphrase.h>
43 #include <signal.h>
44 #include <stdlib.h>
45 #include <stdio.h>
46 #include <syslog.h>
47 #include <limits.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include <login_cap.h>
51 #include <bsd_auth.h>
52 
53 #include "token.h"
54 
55 int
main(int argc,char * argv[])56 main(int argc, char *argv[])
57 {
58 	FILE *back = NULL;
59 	char *username = NULL;
60 	char *instance;
61 	char challenge[1024];
62 	char response[1024];
63 	char *pp = NULL;
64 	int c;
65 	int mode = 0;
66 	struct rlimit cds;
67 	sigset_t blockset;
68 
69 	(void)setpriority(PRIO_PROCESS, 0, 0);
70 
71 	/* We block keyboard-generated signals during database accesses. */
72 	sigemptyset(&blockset);
73 	sigaddset(&blockset, SIGINT);
74 	sigaddset(&blockset, SIGQUIT);
75 	sigaddset(&blockset, SIGTSTP);
76 
77 	openlog(NULL, LOG_ODELAY, LOG_AUTH);
78 
79 	cds.rlim_cur = 0;
80 	cds.rlim_max = 0;
81 	if (setrlimit(RLIMIT_CORE, &cds) == -1)
82 		syslog(LOG_ERR, "couldn't set core dump size to 0: %m");
83 
84 	if (pledge("stdio rpath wpath cpath fattr flock getpw tty", NULL) == -1) {
85 		syslog(LOG_ERR, "pledge: %m");
86 		exit(1);
87 	}
88 
89 	(void)sigprocmask(SIG_BLOCK, &blockset, NULL);
90 	if (token_init(argv[0]) < 0) {
91 		syslog(LOG_ERR, "unknown token type");
92 		errx(1, "unknown token type");
93 	}
94 	(void)sigprocmask(SIG_UNBLOCK, &blockset, NULL);
95 
96 	while ((c = getopt(argc, argv, "ds:v:")) != -1)
97 		switch (c) {
98 		case 'd':		/* to remain undocumented */
99 			back = stdout;
100 			break;
101 		case 'v':
102 			break;
103 		case 's':	/* service */
104 			if (strcmp(optarg, "login") == 0)
105 				mode = 0;
106 			else if (strcmp(optarg, "challenge") == 0)
107 				mode = 1;
108 			else if (strcmp(optarg, "response") == 0)
109 				mode = 2;
110 			else {
111 				syslog(LOG_ERR, "%s: invalid service", optarg);
112 				exit(1);
113 			}
114 			break;
115 		default:
116 			syslog(LOG_ERR, "usage error");
117 			exit(1);
118 		}
119 
120 	switch (argc - optind) {
121 	case 2:
122 	case 1:
123 		username = argv[optind];
124 		break;
125 	default:
126 		syslog(LOG_ERR, "usage error");
127 		exit(1);
128 	}
129 
130 
131 	if (back == NULL && (back = fdopen(3, "r+")) == NULL)  {
132 		syslog(LOG_ERR, "reopening back channel");
133 		exit(1);
134 	}
135 	if (mode == 2) {
136 		mode = 0;
137 		c = -1;
138 		while (++c < sizeof(challenge) &&
139 		    read(3, &challenge[c], 1) == 1) {
140 			if (challenge[c] == '\0' && ++mode == 2)
141 				break;
142 			if (challenge[c] == '\0' && mode == 1)
143 				pp = challenge + c + 1;
144 		}
145 		if (mode < 2) {
146 			syslog(LOG_ERR, "protocol error on back channel");
147 			exit(1);
148 		}
149 	} else {
150 		(void)sigprocmask(SIG_BLOCK, &blockset, NULL);
151 		tokenchallenge(username, challenge, sizeof(challenge),
152 		    tt->proper);
153 		(void)sigprocmask(SIG_UNBLOCK, &blockset, NULL);
154 		if (mode == 1) {
155 			char *val = auth_mkvalue(challenge);
156 			if (val == NULL) {
157 				(void)fprintf(back, BI_VALUE " errormsg %s\n",
158 				    "unable to allocate memory");
159 				(void)fprintf(back, BI_REJECT "\n");
160 				exit(1);
161 			}
162 			fprintf(back, BI_VALUE " challenge %s\n", val);
163 			fprintf(back, BI_CHALLENGE "\n");
164 			exit(0);
165 		}
166 
167 		pp = readpassphrase(challenge, response, sizeof(response), 0);
168 		if (pp == NULL)
169 			exit(1);
170 		if (*pp == '\0') {
171 			char buf[64];
172 			snprintf(buf, sizeof(buf), "%s Response [echo on]: ",
173 			    tt->proper);
174 			pp = readpassphrase(buf, response, sizeof(response),
175 			    RPP_ECHO_ON);
176 			if (pp == NULL)
177 				exit(1);
178 		}
179 	}
180 
181 	(void)sigprocmask(SIG_BLOCK, &blockset, NULL);
182 	if (tokenverify(username, challenge, pp) == 0) {
183 		fprintf(back, BI_AUTH "\n");
184 
185 		if ((instance = strchr(username, '.'))) {
186 			*instance++ = 0;
187 			if (strcmp(instance, "root") == 0)
188 				fprintf(back, BI_ROOTOKAY "\n");
189 		}
190 		fprintf(back, BI_SECURE "\n");
191 		exit(0);
192 	}
193 
194 	fprintf(back, BI_REJECT "\n");
195 	exit(1);
196 }
197