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 $");
27 RCSID("$FreeBSD: src/crypto/openssh/auth2-chall.c,v 1.1.1.1.2.3 2003/02/03 17:31:06 des Exp $");
38 static int auth2_challenge_start(Authctxt *);
39 static int send_userauth_info_request(Authctxt *);
40 static void input_userauth_info_response(int, u_int32_t, void *);
43 extern KbdintDevice bsdauth_device;
46 extern KbdintDevice pam_device;
49 extern KbdintDevice skey_device;
53 KbdintDevice *devices[] = {
67 typedef struct KbdintAuthctxt KbdintAuthctxt;
76 static KbdintAuthctxt *
77 kbdint_alloc(const char *devs)
79 KbdintAuthctxt *kbdintctxt;
83 kbdintctxt = xmalloc(sizeof(KbdintAuthctxt));
84 if (strcmp(devs, "") == 0) {
86 for (i = 0; devices[i]; i++) {
87 if (buffer_len(&b) > 0)
88 buffer_append(&b, ",", 1);
89 buffer_append(&b, devices[i]->name,
90 strlen(devices[i]->name));
92 buffer_append(&b, "\0", 1);
93 kbdintctxt->devices = xstrdup(buffer_ptr(&b));
96 kbdintctxt->devices = xstrdup(devs);
98 debug("kbdint_alloc: devices '%s'", kbdintctxt->devices);
99 kbdintctxt->ctxt = NULL;
100 kbdintctxt->device = NULL;
101 kbdintctxt->nreq = 0;
106 kbdint_reset_device(KbdintAuthctxt *kbdintctxt)
108 if (kbdintctxt->ctxt) {
109 kbdintctxt->device->free_ctx(kbdintctxt->ctxt);
110 kbdintctxt->ctxt = NULL;
112 kbdintctxt->device = NULL;
115 kbdint_free(KbdintAuthctxt *kbdintctxt)
117 if (kbdintctxt->device)
118 kbdint_reset_device(kbdintctxt);
119 if (kbdintctxt->devices) {
120 xfree(kbdintctxt->devices);
121 kbdintctxt->devices = NULL;
125 /* get next device */
127 kbdint_next_device(KbdintAuthctxt *kbdintctxt)
133 if (kbdintctxt->device)
134 kbdint_reset_device(kbdintctxt);
136 len = kbdintctxt->devices ?
137 strcspn(kbdintctxt->devices, ",") : 0;
141 for (i = 0; devices[i]; i++)
142 if (strncmp(kbdintctxt->devices, devices[i]->name, len) == 0)
143 kbdintctxt->device = devices[i];
144 t = kbdintctxt->devices;
145 kbdintctxt->devices = t[len] ? xstrdup(t+len+1) : NULL;
147 debug2("kbdint_next_device: devices %s", kbdintctxt->devices ?
148 kbdintctxt->devices : "<empty>");
149 } while (kbdintctxt->devices && !kbdintctxt->device);
151 return kbdintctxt->device ? 1 : 0;
155 * try challenge-response, set authctxt->postponed if we have to
156 * wait for the response.
159 auth2_challenge(Authctxt *authctxt, char *devs)
161 debug("auth2_challenge: user=%s devs=%s",
162 authctxt->user ? authctxt->user : "<nouser>",
163 devs ? devs : "<no devs>");
165 if (authctxt->user == NULL || !devs)
167 if (authctxt->kbdintctxt == NULL)
168 authctxt->kbdintctxt = kbdint_alloc(devs);
169 return auth2_challenge_start(authctxt);
172 /* unregister kbd-int callbacks and context */
174 auth2_challenge_stop(Authctxt *authctxt)
176 /* unregister callback */
177 dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL);
178 if (authctxt->kbdintctxt != NULL) {
179 kbdint_free(authctxt->kbdintctxt);
180 authctxt->kbdintctxt = NULL;
184 /* side effect: sets authctxt->postponed if a reply was sent*/
186 auth2_challenge_start(Authctxt *authctxt)
188 KbdintAuthctxt *kbdintctxt = authctxt->kbdintctxt;
190 debug2("auth2_challenge_start: devices %s",
191 kbdintctxt->devices ? kbdintctxt->devices : "<empty>");
193 if (kbdint_next_device(kbdintctxt) == 0) {
194 auth2_challenge_stop(authctxt);
197 debug("auth2_challenge_start: trying authentication method '%s'",
198 kbdintctxt->device->name);
200 if ((kbdintctxt->ctxt = kbdintctxt->device->init_ctx(authctxt)) == NULL) {
201 auth2_challenge_stop(authctxt);
204 if (send_userauth_info_request(authctxt) == 0) {
205 auth2_challenge_stop(authctxt);
208 dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE,
209 &input_userauth_info_response);
211 authctxt->postponed = 1;
216 send_userauth_info_request(Authctxt *authctxt)
218 KbdintAuthctxt *kbdintctxt;
219 char *name, *instr, **prompts;
223 kbdintctxt = authctxt->kbdintctxt;
224 if (kbdintctxt->device->query(kbdintctxt->ctxt,
225 &name, &instr, &kbdintctxt->nreq, &prompts, &echo_on))
228 packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
229 packet_put_cstring(name);
230 packet_put_cstring(instr);
231 packet_put_cstring(""); /* language not used */
232 packet_put_int(kbdintctxt->nreq);
233 for (i = 0; i < kbdintctxt->nreq; i++) {
234 packet_put_cstring(prompts[i]);
235 packet_put_char(echo_on[i]);
240 for (i = 0; i < kbdintctxt->nreq; i++)
250 input_userauth_info_response(int type, u_int32_t seq, void *ctxt)
252 Authctxt *authctxt = ctxt;
253 KbdintAuthctxt *kbdintctxt;
254 int i, authenticated = 0, res, len;
256 char **response = NULL, *method;
258 if (authctxt == NULL)
259 fatal("input_userauth_info_response: no authctxt");
260 kbdintctxt = authctxt->kbdintctxt;
261 if (kbdintctxt == NULL || kbdintctxt->ctxt == NULL)
262 fatal("input_userauth_info_response: no kbdintctxt");
263 if (kbdintctxt->device == NULL)
264 fatal("input_userauth_info_response: no device");
266 authctxt->postponed = 0; /* reset */
267 nresp = packet_get_int();
268 if (nresp != kbdintctxt->nreq)
269 fatal("input_userauth_info_response: wrong number of replies");
271 fatal("input_userauth_info_response: too many replies");
273 response = xmalloc(nresp * sizeof(char *));
274 for (i = 0; i < nresp; i++)
275 response[i] = packet_get_string(NULL);
279 if (authctxt->valid) {
280 res = kbdintctxt->device->respond(kbdintctxt->ctxt,
286 for (i = 0; i < nresp; i++) {
287 memset(response[i], 'r', strlen(response[i]));
299 /* Authentication needs further interaction */
300 if (send_userauth_info_request(authctxt) == 1)
301 authctxt->postponed = 1;
308 len = strlen("keyboard-interactive") + 2 +
309 strlen(kbdintctxt->device->name);
310 method = xmalloc(len);
311 snprintf(method, len, "keyboard-interactive/%s",
312 kbdintctxt->device->name);
314 if (!authctxt->postponed) {
316 auth2_challenge_stop(authctxt);
318 /* start next device */
319 /* may set authctxt->postponed */
320 auth2_challenge_start(authctxt);
323 userauth_finish(authctxt, authenticated, method);
328 privsep_challenge_enable(void)
331 extern KbdintDevice mm_bsdauth_device;
334 extern KbdintDevice mm_pam_device;
337 extern KbdintDevice mm_skey_device;
342 devices[n++] = &mm_bsdauth_device;
345 devices[n++] = &mm_pam_device;
348 devices[n++] = &mm_skey_device;