]> andersk Git - gssapi-openssh.git/blame - openssh/auth2-chall.c
Import of OpenSSH 5.2p1
[gssapi-openssh.git] / openssh / auth2-chall.c
CommitLineData
91d9cdd3 1/* $OpenBSD: auth2-chall.c,v 1.34 2008/12/09 04:32:22 djm Exp $ */
3c0ef626 2/*
3 * Copyright (c) 2001 Markus Friedl. All rights reserved.
4 * Copyright (c) 2001 Per Allansson. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
9108f8d9 26
3c0ef626 27#include "includes.h"
3c0ef626 28
9108f8d9 29#include <sys/types.h>
30
31#include <stdarg.h>
32#include <stdio.h>
33#include <string.h>
34
35#include "xmalloc.h"
3c0ef626 36#include "ssh2.h"
9108f8d9 37#include "key.h"
38#include "hostfile.h"
3c0ef626 39#include "auth.h"
e9a17296 40#include "buffer.h"
3c0ef626 41#include "packet.h"
3c0ef626 42#include "dispatch.h"
3c0ef626 43#include "log.h"
996d5e62 44#include "servconf.h"
45
46/* import */
47extern ServerOptions options;
3c0ef626 48
49static int auth2_challenge_start(Authctxt *);
50static int send_userauth_info_request(Authctxt *);
e9a17296 51static void input_userauth_info_response(int, u_int32_t, void *);
3c0ef626 52
53#ifdef BSD_AUTH
54extern KbdintDevice bsdauth_device;
55#else
0fff78ff 56#ifdef USE_PAM
57extern KbdintDevice sshpam_device;
58#endif
3c0ef626 59#ifdef SKEY
60extern KbdintDevice skey_device;
61#endif
62#endif
63
64KbdintDevice *devices[] = {
65#ifdef BSD_AUTH
66 &bsdauth_device,
67#else
0fff78ff 68#ifdef USE_PAM
69 &sshpam_device,
70#endif
3c0ef626 71#ifdef SKEY
72 &skey_device,
73#endif
74#endif
75 NULL
76};
77
78typedef struct KbdintAuthctxt KbdintAuthctxt;
79struct KbdintAuthctxt
80{
81 char *devices;
82 void *ctxt;
83 KbdintDevice *device;
680cee3b 84 u_int nreq;
3c0ef626 85};
86
996d5e62 87#ifdef USE_PAM
88void
89remove_kbdint_device(const char *devname)
90{
91 int i, j;
92
93 for (i = 0; devices[i] != NULL; i++)
94 if (strcmp(devices[i]->name, devname) == 0) {
95 for (j = i; devices[j] != NULL; j++)
96 devices[j] = devices[j+1];
97 i--;
98 }
99}
100#endif
101
3c0ef626 102static KbdintAuthctxt *
103kbdint_alloc(const char *devs)
104{
105 KbdintAuthctxt *kbdintctxt;
e9a17296 106 Buffer b;
3c0ef626 107 int i;
3c0ef626 108
996d5e62 109#ifdef USE_PAM
110 if (!options.use_pam)
111 remove_kbdint_device("pam");
112#endif
113
3c0ef626 114 kbdintctxt = xmalloc(sizeof(KbdintAuthctxt));
115 if (strcmp(devs, "") == 0) {
e9a17296 116 buffer_init(&b);
3c0ef626 117 for (i = 0; devices[i]; i++) {
e9a17296 118 if (buffer_len(&b) > 0)
119 buffer_append(&b, ",", 1);
120 buffer_append(&b, devices[i]->name,
121 strlen(devices[i]->name));
3c0ef626 122 }
e9a17296 123 buffer_append(&b, "\0", 1);
124 kbdintctxt->devices = xstrdup(buffer_ptr(&b));
125 buffer_free(&b);
3c0ef626 126 } else {
127 kbdintctxt->devices = xstrdup(devs);
128 }
e9a17296 129 debug("kbdint_alloc: devices '%s'", kbdintctxt->devices);
3c0ef626 130 kbdintctxt->ctxt = NULL;
131 kbdintctxt->device = NULL;
680cee3b 132 kbdintctxt->nreq = 0;
3c0ef626 133
134 return kbdintctxt;
135}
136static void
137kbdint_reset_device(KbdintAuthctxt *kbdintctxt)
138{
139 if (kbdintctxt->ctxt) {
140 kbdintctxt->device->free_ctx(kbdintctxt->ctxt);
141 kbdintctxt->ctxt = NULL;
142 }
143 kbdintctxt->device = NULL;
144}
145static void
146kbdint_free(KbdintAuthctxt *kbdintctxt)
147{
148 if (kbdintctxt->device)
149 kbdint_reset_device(kbdintctxt);
150 if (kbdintctxt->devices) {
151 xfree(kbdintctxt->devices);
152 kbdintctxt->devices = NULL;
153 }
154 xfree(kbdintctxt);
155}
156/* get next device */
157static int
158kbdint_next_device(KbdintAuthctxt *kbdintctxt)
159{
160 size_t len;
161 char *t;
162 int i;
163
164 if (kbdintctxt->device)
165 kbdint_reset_device(kbdintctxt);
166 do {
167 len = kbdintctxt->devices ?
168 strcspn(kbdintctxt->devices, ",") : 0;
169
170 if (len == 0)
171 break;
172 for (i = 0; devices[i]; i++)
173 if (strncmp(kbdintctxt->devices, devices[i]->name, len) == 0)
174 kbdintctxt->device = devices[i];
175 t = kbdintctxt->devices;
176 kbdintctxt->devices = t[len] ? xstrdup(t+len+1) : NULL;
177 xfree(t);
178 debug2("kbdint_next_device: devices %s", kbdintctxt->devices ?
665a873d 179 kbdintctxt->devices : "<empty>");
3c0ef626 180 } while (kbdintctxt->devices && !kbdintctxt->device);
181
182 return kbdintctxt->device ? 1 : 0;
183}
184
185/*
186 * try challenge-response, set authctxt->postponed if we have to
187 * wait for the response.
188 */
189int
190auth2_challenge(Authctxt *authctxt, char *devs)
191{
192 debug("auth2_challenge: user=%s devs=%s",
193 authctxt->user ? authctxt->user : "<nouser>",
194 devs ? devs : "<no devs>");
195
196 if (authctxt->user == NULL || !devs)
197 return 0;
e9a17296 198 if (authctxt->kbdintctxt == NULL)
3c0ef626 199 authctxt->kbdintctxt = kbdint_alloc(devs);
200 return auth2_challenge_start(authctxt);
201}
202
e9a17296 203/* unregister kbd-int callbacks and context */
204void
205auth2_challenge_stop(Authctxt *authctxt)
206{
207 /* unregister callback */
208 dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL);
799ae497 209 if (authctxt->kbdintctxt != NULL) {
e9a17296 210 kbdint_free(authctxt->kbdintctxt);
211 authctxt->kbdintctxt = NULL;
212 }
213}
214
3c0ef626 215/* side effect: sets authctxt->postponed if a reply was sent*/
216static int
217auth2_challenge_start(Authctxt *authctxt)
218{
219 KbdintAuthctxt *kbdintctxt = authctxt->kbdintctxt;
220
221 debug2("auth2_challenge_start: devices %s",
222 kbdintctxt->devices ? kbdintctxt->devices : "<empty>");
223
224 if (kbdint_next_device(kbdintctxt) == 0) {
e9a17296 225 auth2_challenge_stop(authctxt);
3c0ef626 226 return 0;
227 }
228 debug("auth2_challenge_start: trying authentication method '%s'",
229 kbdintctxt->device->name);
230
231 if ((kbdintctxt->ctxt = kbdintctxt->device->init_ctx(authctxt)) == NULL) {
e9a17296 232 auth2_challenge_stop(authctxt);
3c0ef626 233 return 0;
234 }
235 if (send_userauth_info_request(authctxt) == 0) {
e9a17296 236 auth2_challenge_stop(authctxt);
3c0ef626 237 return 0;
238 }
239 dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE,
240 &input_userauth_info_response);
241
242 authctxt->postponed = 1;
243 return 0;
244}
245
246static int
247send_userauth_info_request(Authctxt *authctxt)
248{
249 KbdintAuthctxt *kbdintctxt;
250 char *name, *instr, **prompts;
665a873d 251 u_int i, *echo_on;
3c0ef626 252
253 kbdintctxt = authctxt->kbdintctxt;
254 if (kbdintctxt->device->query(kbdintctxt->ctxt,
680cee3b 255 &name, &instr, &kbdintctxt->nreq, &prompts, &echo_on))
3c0ef626 256 return 0;
257
258 packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
259 packet_put_cstring(name);
260 packet_put_cstring(instr);
f5799ae1 261 packet_put_cstring(""); /* language not used */
680cee3b 262 packet_put_int(kbdintctxt->nreq);
263 for (i = 0; i < kbdintctxt->nreq; i++) {
3c0ef626 264 packet_put_cstring(prompts[i]);
265 packet_put_char(echo_on[i]);
266 }
267 packet_send();
268 packet_write_wait();
269
680cee3b 270 for (i = 0; i < kbdintctxt->nreq; i++)
3c0ef626 271 xfree(prompts[i]);
272 xfree(prompts);
273 xfree(echo_on);
274 xfree(name);
275 xfree(instr);
276 return 1;
277}
278
279static void
e9a17296 280input_userauth_info_response(int type, u_int32_t seq, void *ctxt)
3c0ef626 281{
282 Authctxt *authctxt = ctxt;
283 KbdintAuthctxt *kbdintctxt;
91d9cdd3 284 int authenticated = 0, res;
665a873d 285 u_int i, nresp;
3c0ef626 286 char **response = NULL, *method;
287
288 if (authctxt == NULL)
289 fatal("input_userauth_info_response: no authctxt");
290 kbdintctxt = authctxt->kbdintctxt;
291 if (kbdintctxt == NULL || kbdintctxt->ctxt == NULL)
292 fatal("input_userauth_info_response: no kbdintctxt");
293 if (kbdintctxt->device == NULL)
294 fatal("input_userauth_info_response: no device");
295
296 authctxt->postponed = 0; /* reset */
297 nresp = packet_get_int();
680cee3b 298 if (nresp != kbdintctxt->nreq)
299 fatal("input_userauth_info_response: wrong number of replies");
300 if (nresp > 100)
301 fatal("input_userauth_info_response: too many replies");
3c0ef626 302 if (nresp > 0) {
9108f8d9 303 response = xcalloc(nresp, sizeof(char *));
3c0ef626 304 for (i = 0; i < nresp; i++)
305 response[i] = packet_get_string(NULL);
306 }
e9a17296 307 packet_check_eom();
3c0ef626 308
996d5e62 309 res = kbdintctxt->device->respond(kbdintctxt->ctxt, nresp, response);
3c0ef626 310
311 for (i = 0; i < nresp; i++) {
312 memset(response[i], 'r', strlen(response[i]));
313 xfree(response[i]);
314 }
315 if (response)
316 xfree(response);
317
318 switch (res) {
319 case 0:
320 /* Success! */
996d5e62 321 authenticated = authctxt->valid ? 1 : 0;
3c0ef626 322 break;
323 case 1:
324 /* Authentication needs further interaction */
e9a17296 325 if (send_userauth_info_request(authctxt) == 1)
326 authctxt->postponed = 1;
3c0ef626 327 break;
328 default:
329 /* Failure! */
330 break;
331 }
332
91d9cdd3 333 xasprintf(&method, "keyboard-interactive/%s", kbdintctxt->device->name);
3c0ef626 334
335 if (!authctxt->postponed) {
3c0ef626 336 if (authenticated) {
e9a17296 337 auth2_challenge_stop(authctxt);
3c0ef626 338 } else {
339 /* start next device */
340 /* may set authctxt->postponed */
341 auth2_challenge_start(authctxt);
342 }
343 }
344 userauth_finish(authctxt, authenticated, method);
345 xfree(method);
346}
700318f3 347
348void
349privsep_challenge_enable(void)
350{
0fff78ff 351#if defined(BSD_AUTH) || defined(USE_PAM) || defined(SKEY)
352 int n = 0;
353#endif
700318f3 354#ifdef BSD_AUTH
355 extern KbdintDevice mm_bsdauth_device;
356#endif
0fff78ff 357#ifdef USE_PAM
358 extern KbdintDevice mm_sshpam_device;
359#endif
700318f3 360#ifdef SKEY
361 extern KbdintDevice mm_skey_device;
362#endif
0fff78ff 363
700318f3 364#ifdef BSD_AUTH
0fff78ff 365 devices[n++] = &mm_bsdauth_device;
700318f3 366#else
0fff78ff 367#ifdef USE_PAM
368 devices[n++] = &mm_sshpam_device;
369#endif
700318f3 370#ifdef SKEY
0fff78ff 371 devices[n++] = &mm_skey_device;
700318f3 372#endif
373#endif
374}
This page took 0.90186 seconds and 5 git commands to generate.