1 /* $OpenBSD: auth-chall.c,v 1.12 2006/08/03 03:34:41 deraadt Exp $ */
2 /*
3  * Copyright (c) 2001 Markus Friedl.  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  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/types.h>
27 
28 #include "xmalloc.h"
29 #include "key.h"
30 #include "hostfile.h"
31 #include "auth.h"
32 #include "log.h"
33 
34 /* limited protocol v1 interface to kbd-interactive authentication */
35 
36 extern KbdintDevice *devices[];
37 static KbdintDevice *device;
38 
39 char *
get_challenge(Authctxt * authctxt)40 get_challenge(Authctxt *authctxt)
41 {
42 	char *challenge, *name, *info, **prompts;
43 	u_int i, numprompts;
44 	u_int *echo_on;
45 
46 	device = devices[0]; /* we always use the 1st device for protocol 1 */
47 	if (device == NULL)
48 		return NULL;
49 	if ((authctxt->kbdintctxt = device->init_ctx(authctxt)) == NULL)
50 		return NULL;
51 	if (device->query(authctxt->kbdintctxt, &name, &info,
52 	    &numprompts, &prompts, &echo_on)) {
53 		device->free_ctx(authctxt->kbdintctxt);
54 		authctxt->kbdintctxt = NULL;
55 		return NULL;
56 	}
57 	if (numprompts < 1)
58 		fatal("get_challenge: numprompts < 1");
59 	challenge = xstrdup(prompts[0]);
60 	for (i = 0; i < numprompts; i++)
61 		xfree(prompts[i]);
62 	xfree(prompts);
63 	xfree(name);
64 	xfree(echo_on);
65 	xfree(info);
66 
67 	return (challenge);
68 }
69 int
verify_response(Authctxt * authctxt,const char * response)70 verify_response(Authctxt *authctxt, const char *response)
71 {
72 	char *resp[1];
73 	int authenticated = 0;
74 
75 	if (device == NULL)
76 		return 0;
77 	if (authctxt->kbdintctxt == NULL)
78 		return 0;
79 	resp[0] = (char *)response;
80 	if (device->respond(authctxt->kbdintctxt, 1, resp) == 0)
81 		authenticated = 1;
82 	device->free_ctx(authctxt->kbdintctxt);
83 	authctxt->kbdintctxt = NULL;
84 	return authenticated;
85 }
86