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;