2 * Copyright (c) 2001 Markus Friedl. All rights reserved.
3 * Copyright (c) 2001 Per Allansson. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
26 RCSID("$OpenBSD: auth2-chall.c,v 1.20 2002/06/30 21:59:45 deraadt Exp $");
37 static int auth2_challenge_start(Authctxt
*);
38 static int send_userauth_info_request(Authctxt
*);
39 static void input_userauth_info_response(int, u_int32_t
, void *);
42 extern KbdintDevice bsdauth_device
;
45 extern KbdintDevice sshpam_device
;
48 extern KbdintDevice skey_device
;
52 KbdintDevice
*devices
[] = {
66 typedef struct KbdintAuthctxt KbdintAuthctxt
;
75 static KbdintAuthctxt
*
76 kbdint_alloc(const char *devs
)
78 KbdintAuthctxt
*kbdintctxt
;
82 kbdintctxt
= xmalloc(sizeof(KbdintAuthctxt
));
83 if (strcmp(devs
, "") == 0) {
85 for (i
= 0; devices
[i
]; i
++) {
86 if (buffer_len(&b
) > 0)
87 buffer_append(&b
, ",", 1);
88 buffer_append(&b
, devices
[i
]->name
,
89 strlen(devices
[i
]->name
));
91 buffer_append(&b
, "\0", 1);
92 kbdintctxt
->devices
= xstrdup(buffer_ptr(&b
));
95 kbdintctxt
->devices
= xstrdup(devs
);
97 debug("kbdint_alloc: devices '%s'", kbdintctxt
->devices
);
98 kbdintctxt
->ctxt
= NULL
;
99 kbdintctxt
->device
= NULL
;
100 kbdintctxt
->nreq
= 0;
105 kbdint_reset_device(KbdintAuthctxt
*kbdintctxt
)
107 if (kbdintctxt
->ctxt
) {
108 kbdintctxt
->device
->free_ctx(kbdintctxt
->ctxt
);
109 kbdintctxt
->ctxt
= NULL
;
111 kbdintctxt
->device
= NULL
;
114 kbdint_free(KbdintAuthctxt
*kbdintctxt
)
116 if (kbdintctxt
->device
)
117 kbdint_reset_device(kbdintctxt
);
118 if (kbdintctxt
->devices
) {
119 xfree(kbdintctxt
->devices
);
120 kbdintctxt
->devices
= NULL
;
124 /* get next device */
126 kbdint_next_device(KbdintAuthctxt
*kbdintctxt
)
132 if (kbdintctxt
->device
)
133 kbdint_reset_device(kbdintctxt
);
135 len
= kbdintctxt
->devices
?
136 strcspn(kbdintctxt
->devices
, ",") : 0;
140 for (i
= 0; devices
[i
]; i
++)
141 if (strncmp(kbdintctxt
->devices
, devices
[i
]->name
, len
) == 0)
142 kbdintctxt
->device
= devices
[i
];
143 t
= kbdintctxt
->devices
;
144 kbdintctxt
->devices
= t
[len
] ? xstrdup(t
+len
+1) : NULL
;
146 debug2("kbdint_next_device: devices %s", kbdintctxt
->devices
?
147 kbdintctxt
->devices
: "<empty>");
148 } while (kbdintctxt
->devices
&& !kbdintctxt
->device
);
150 return kbdintctxt
->device
? 1 : 0;
154 * try challenge-response, set authctxt->postponed if we have to
155 * wait for the response.
158 auth2_challenge(Authctxt
*authctxt
, char *devs
)
160 debug("auth2_challenge: user=%s devs=%s",
161 authctxt
->user
? authctxt
->user
: "<nouser>",
162 devs
? devs
: "<no devs>");
164 if (authctxt
->user
== NULL
|| !devs
)
166 if (authctxt
->kbdintctxt
== NULL
)
167 authctxt
->kbdintctxt
= kbdint_alloc(devs
);
168 return auth2_challenge_start(authctxt
);
171 /* unregister kbd-int callbacks and context */
173 auth2_challenge_stop(Authctxt
*authctxt
)
175 /* unregister callback */
176 dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE
, NULL
);
177 if (authctxt
->kbdintctxt
!= NULL
) {
178 kbdint_free(authctxt
->kbdintctxt
);
179 authctxt
->kbdintctxt
= NULL
;
183 /* side effect: sets authctxt->postponed if a reply was sent*/
185 auth2_challenge_start(Authctxt
*authctxt
)
187 KbdintAuthctxt
*kbdintctxt
= authctxt
->kbdintctxt
;
189 debug2("auth2_challenge_start: devices %s",
190 kbdintctxt
->devices
? kbdintctxt
->devices
: "<empty>");
192 if (kbdint_next_device(kbdintctxt
) == 0) {
193 auth2_challenge_stop(authctxt
);
196 debug("auth2_challenge_start: trying authentication method '%s'",
197 kbdintctxt
->device
->name
);
199 if ((kbdintctxt
->ctxt
= kbdintctxt
->device
->init_ctx(authctxt
)) == NULL
) {
200 auth2_challenge_stop(authctxt
);
203 if (send_userauth_info_request(authctxt
) == 0) {
204 auth2_challenge_stop(authctxt
);
207 dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE
,
208 &input_userauth_info_response
);
210 authctxt
->postponed
= 1;
215 send_userauth_info_request(Authctxt
*authctxt
)
217 KbdintAuthctxt
*kbdintctxt
;
218 char *name
, *instr
, **prompts
;
222 kbdintctxt
= authctxt
->kbdintctxt
;
223 if (kbdintctxt
->device
->query(kbdintctxt
->ctxt
,
224 &name
, &instr
, &kbdintctxt
->nreq
, &prompts
, &echo_on
))
227 packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST
);
228 packet_put_cstring(name
);
229 packet_put_cstring(instr
);
230 packet_put_cstring(""); /* language not used */
231 packet_put_int(kbdintctxt
->nreq
);
232 for (i
= 0; i
< kbdintctxt
->nreq
; i
++) {
233 packet_put_cstring(prompts
[i
]);
234 packet_put_char(echo_on
[i
]);
239 for (i
= 0; i
< kbdintctxt
->nreq
; i
++)
249 input_userauth_info_response(int type
, u_int32_t seq
, void *ctxt
)
251 Authctxt
*authctxt
= ctxt
;
252 KbdintAuthctxt
*kbdintctxt
;
253 int i
, authenticated
= 0, res
, len
;
255 char **response
= NULL
, *method
;
257 if (authctxt
== NULL
)
258 fatal("input_userauth_info_response: no authctxt");
259 kbdintctxt
= authctxt
->kbdintctxt
;
260 if (kbdintctxt
== NULL
|| kbdintctxt
->ctxt
== NULL
)
261 fatal("input_userauth_info_response: no kbdintctxt");
262 if (kbdintctxt
->device
== NULL
)
263 fatal("input_userauth_info_response: no device");
265 authctxt
->postponed
= 0; /* reset */
266 nresp
= packet_get_int();
267 if (nresp
!= kbdintctxt
->nreq
)
268 fatal("input_userauth_info_response: wrong number of replies");
270 fatal("input_userauth_info_response: too many replies");
272 response
= xmalloc(nresp
* sizeof(char *));
273 for (i
= 0; i
< nresp
; i
++)
274 response
[i
] = packet_get_string(NULL
);
278 if (authctxt
->valid
) {
279 res
= kbdintctxt
->device
->respond(kbdintctxt
->ctxt
,
285 for (i
= 0; i
< nresp
; i
++) {
286 memset(response
[i
], 'r', strlen(response
[i
]));
298 /* Authentication needs further interaction */
299 if (send_userauth_info_request(authctxt
) == 1)
300 authctxt
->postponed
= 1;
307 len
= strlen("keyboard-interactive") + 2 +
308 strlen(kbdintctxt
->device
->name
);
309 method
= xmalloc(len
);
310 snprintf(method
, len
, "keyboard-interactive/%s",
311 kbdintctxt
->device
->name
);
313 if (!authctxt
->postponed
) {
315 auth2_challenge_stop(authctxt
);
317 /* start next device */
318 /* may set authctxt->postponed */
319 auth2_challenge_start(authctxt
);
322 userauth_finish(authctxt
, authenticated
, method
);
327 privsep_challenge_enable(void)
329 #if defined(BSD_AUTH) || defined(USE_PAM) || defined(SKEY)
333 extern KbdintDevice mm_bsdauth_device
;
336 extern KbdintDevice mm_sshpam_device
;
339 extern KbdintDevice mm_skey_device
;
343 devices
[n
++] = &mm_bsdauth_device
;
346 devices
[n
++] = &mm_sshpam_device
;
349 devices
[n
++] = &mm_skey_device
;