1/*
2 * Copyright (c) 2001 Markus Friedl. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include "includes.h"
26RCSID("$OpenBSD: auth-chall.c,v 1.9 2003/11/03 09:03:37 djm Exp $");
27RCSID("$FreeBSD: head/crypto/openssh/auth-chall.c 147005 2005-06-05 15:46:09Z des $");
28
29#include "auth.h"
30#include "log.h"
31#include "xmalloc.h"
32#include "servconf.h"
33
34/* limited protocol v1 interface to kbd-interactive authentication */
35
36extern KbdintDevice *devices[];
37static KbdintDevice *device;
38extern ServerOptions options;
39
40char *
41get_challenge(Authctxt *authctxt)
42{
43 char *challenge, *name, *info, **prompts;
44 u_int i, numprompts;
45 u_int *echo_on;
46
47#ifdef USE_PAM
48 if (!options.use_pam)
49 remove_kbdint_device("pam");
50#endif
51
52 device = devices[0]; /* we always use the 1st device for protocol 1 */
53 if (device == NULL)
54 return NULL;
55 if ((authctxt->kbdintctxt = device->init_ctx(authctxt)) == NULL)
56 return NULL;
57 if (device->query(authctxt->kbdintctxt, &name, &info,
58 &numprompts, &prompts, &echo_on)) {
59 device->free_ctx(authctxt->kbdintctxt);
60 authctxt->kbdintctxt = NULL;
61 return NULL;
62 }
63 if (numprompts < 1)
64 fatal("get_challenge: numprompts < 1");
65 challenge = xstrdup(prompts[0]);
66 for (i = 0; i < numprompts; i++)
67 xfree(prompts[i]);
68 xfree(prompts);
69 xfree(name);
70 xfree(echo_on);
71 xfree(info);
72
73 return (challenge);
74}
75int
76verify_response(Authctxt *authctxt, const char *response)
77{
78 char *resp[1], *name, *info, **prompts;
79 u_int i, numprompts, *echo_on;
80 int authenticated = 0;
81
82 if (device == NULL)
83 return 0;
84 if (authctxt->kbdintctxt == NULL)
85 return 0;
86 resp[0] = (char *)response;
87 switch (device->respond(authctxt->kbdintctxt, 1, resp)) {
88 case 0: /* Success */
89 authenticated = 1;
90 break;
91 case 1: /* Postponed - retry with empty query for PAM */
92 if ((device->query(authctxt->kbdintctxt, &name, &info,
93 &numprompts, &prompts, &echo_on)) != 0)
94 break;
95 if (numprompts == 0 &&
96 device->respond(authctxt->kbdintctxt, 0, resp) == 0)
97 authenticated = 1;
98
99 for (i = 0; i < numprompts; i++)
100 xfree(prompts[i]);
101 xfree(prompts);
102 xfree(name);
103 xfree(echo_on);
104 xfree(info);
105 break;
106 }
107 device->free_ctx(authctxt->kbdintctxt);
108 authctxt->kbdintctxt = NULL;
109 return authenticated;
110}
111void
112abandon_challenge_response(Authctxt *authctxt)
113{
114 if (authctxt->kbdintctxt != NULL) {
115 device->free_ctx(authctxt->kbdintctxt);
116 authctxt->kbdintctxt = NULL;
117 }
118}