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1 | /* $OpenBSD: monitor.c,v 1.97 2008/06/13 13:56:59 dtucker Exp $ */ | |
2 | /* | |
3 | * Copyright 2002 Niels Provos <provos@citi.umich.edu> | |
4 | * Copyright 2002 Markus Friedl <markus@openbsd.org> | |
5 | * All rights reserved. | |
6 | * | |
7 | * Redistribution and use in source and binary forms, with or without | |
8 | * modification, are permitted provided that the following conditions | |
9 | * are met: | |
10 | * 1. Redistributions of source code must retain the above copyright | |
11 | * notice, this list of conditions and the following disclaimer. | |
12 | * 2. Redistributions in binary form must reproduce the above copyright | |
13 | * notice, this list of conditions and the following disclaimer in the | |
14 | * documentation and/or other materials provided with the distribution. | |
15 | * | |
16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
17 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
18 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
19 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
21 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
22 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
23 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
24 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
25 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
26 | */ | |
27 | ||
28 | #include "includes.h" | |
29 | ||
30 | #include <sys/types.h> | |
31 | #include <sys/param.h> | |
32 | #include <sys/socket.h> | |
33 | #include "openbsd-compat/sys-tree.h" | |
34 | #include <sys/wait.h> | |
35 | ||
36 | #include <errno.h> | |
37 | #include <fcntl.h> | |
38 | #ifdef HAVE_PATHS_H | |
39 | #include <paths.h> | |
40 | #endif | |
41 | #include <pwd.h> | |
42 | #include <signal.h> | |
43 | #include <stdarg.h> | |
44 | #include <stdlib.h> | |
45 | #include <string.h> | |
46 | #include <unistd.h> | |
47 | ||
48 | #ifdef SKEY | |
49 | #include <skey.h> | |
50 | #endif | |
51 | ||
52 | #include <openssl/dh.h> | |
53 | ||
54 | #include "openbsd-compat/sys-queue.h" | |
55 | #include "xmalloc.h" | |
56 | #include "ssh.h" | |
57 | #include "key.h" | |
58 | #include "buffer.h" | |
59 | #include "hostfile.h" | |
60 | #include "auth.h" | |
61 | #include "cipher.h" | |
62 | #include "kex.h" | |
63 | #include "dh.h" | |
64 | #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ | |
65 | #undef TARGET_OS_MAC | |
66 | #include "zlib.h" | |
67 | #define TARGET_OS_MAC 1 | |
68 | #else | |
69 | #include "zlib.h" | |
70 | #endif | |
71 | #include "packet.h" | |
72 | #include "auth-options.h" | |
73 | #include "sshpty.h" | |
74 | #include "channels.h" | |
75 | #include "session.h" | |
76 | #include "sshlogin.h" | |
77 | #include "canohost.h" | |
78 | #include "log.h" | |
79 | #include "servconf.h" | |
80 | #include "monitor.h" | |
81 | #include "monitor_mm.h" | |
82 | #ifdef GSSAPI | |
83 | #include "ssh-gss.h" | |
84 | #endif | |
85 | #include "monitor_wrap.h" | |
86 | #include "monitor_fdpass.h" | |
87 | #include "misc.h" | |
88 | #include "compat.h" | |
89 | #include "ssh2.h" | |
90 | ||
91 | #ifdef GSSAPI | |
92 | static Gssctxt *gsscontext = NULL; | |
93 | #endif | |
94 | ||
95 | /* Imports */ | |
96 | extern ServerOptions options; | |
97 | extern u_int utmp_len; | |
98 | extern Newkeys *current_keys[]; | |
99 | extern z_stream incoming_stream; | |
100 | extern z_stream outgoing_stream; | |
101 | extern u_char session_id[]; | |
102 | extern Buffer input, output; | |
103 | extern Buffer auth_debug; | |
104 | extern int auth_debug_init; | |
105 | extern Buffer loginmsg; | |
106 | ||
107 | /* State exported from the child */ | |
108 | ||
109 | struct { | |
110 | z_stream incoming; | |
111 | z_stream outgoing; | |
112 | u_char *keyin; | |
113 | u_int keyinlen; | |
114 | u_char *keyout; | |
115 | u_int keyoutlen; | |
116 | u_char *ivin; | |
117 | u_int ivinlen; | |
118 | u_char *ivout; | |
119 | u_int ivoutlen; | |
120 | u_char *ssh1key; | |
121 | u_int ssh1keylen; | |
122 | int ssh1cipher; | |
123 | int ssh1protoflags; | |
124 | u_char *input; | |
125 | u_int ilen; | |
126 | u_char *output; | |
127 | u_int olen; | |
128 | } child_state; | |
129 | ||
130 | /* Functions on the monitor that answer unprivileged requests */ | |
131 | ||
132 | int mm_answer_moduli(int, Buffer *); | |
133 | int mm_answer_sign(int, Buffer *); | |
134 | int mm_answer_pwnamallow(int, Buffer *); | |
135 | int mm_answer_auth2_read_banner(int, Buffer *); | |
136 | int mm_answer_authserv(int, Buffer *); | |
137 | int mm_answer_authpassword(int, Buffer *); | |
138 | int mm_answer_bsdauthquery(int, Buffer *); | |
139 | int mm_answer_bsdauthrespond(int, Buffer *); | |
140 | int mm_answer_skeyquery(int, Buffer *); | |
141 | int mm_answer_skeyrespond(int, Buffer *); | |
142 | int mm_answer_keyallowed(int, Buffer *); | |
143 | int mm_answer_keyverify(int, Buffer *); | |
144 | int mm_answer_pty(int, Buffer *); | |
145 | int mm_answer_pty_cleanup(int, Buffer *); | |
146 | int mm_answer_term(int, Buffer *); | |
147 | int mm_answer_rsa_keyallowed(int, Buffer *); | |
148 | int mm_answer_rsa_challenge(int, Buffer *); | |
149 | int mm_answer_rsa_response(int, Buffer *); | |
150 | int mm_answer_sesskey(int, Buffer *); | |
151 | int mm_answer_sessid(int, Buffer *); | |
152 | ||
153 | #ifdef USE_PAM | |
154 | int mm_answer_pam_start(int, Buffer *); | |
155 | int mm_answer_pam_account(int, Buffer *); | |
156 | int mm_answer_pam_init_ctx(int, Buffer *); | |
157 | int mm_answer_pam_query(int, Buffer *); | |
158 | int mm_answer_pam_respond(int, Buffer *); | |
159 | int mm_answer_pam_free_ctx(int, Buffer *); | |
160 | #endif | |
161 | ||
162 | #ifdef GSSAPI | |
163 | int mm_answer_gss_setup_ctx(int, Buffer *); | |
164 | int mm_answer_gss_accept_ctx(int, Buffer *); | |
165 | int mm_answer_gss_userok(int, Buffer *); | |
166 | int mm_answer_gss_checkmic(int, Buffer *); | |
167 | #endif | |
168 | ||
169 | #ifdef SSH_AUDIT_EVENTS | |
170 | int mm_answer_audit_event(int, Buffer *); | |
171 | int mm_answer_audit_command(int, Buffer *); | |
172 | #endif | |
173 | ||
174 | static Authctxt *authctxt; | |
175 | static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ | |
176 | ||
177 | /* local state for key verify */ | |
178 | static u_char *key_blob = NULL; | |
179 | static u_int key_bloblen = 0; | |
180 | static int key_blobtype = MM_NOKEY; | |
181 | static char *hostbased_cuser = NULL; | |
182 | static char *hostbased_chost = NULL; | |
183 | static char *auth_method = "unknown"; | |
184 | static u_int session_id2_len = 0; | |
185 | static u_char *session_id2 = NULL; | |
186 | static pid_t monitor_child_pid; | |
187 | ||
188 | struct mon_table { | |
189 | enum monitor_reqtype type; | |
190 | int flags; | |
191 | int (*f)(int, Buffer *); | |
192 | }; | |
193 | ||
194 | #define MON_ISAUTH 0x0004 /* Required for Authentication */ | |
195 | #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ | |
196 | #define MON_ONCE 0x0010 /* Disable after calling */ | |
197 | #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ | |
198 | ||
199 | #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) | |
200 | ||
201 | #define MON_PERMIT 0x1000 /* Request is permitted */ | |
202 | ||
203 | struct mon_table mon_dispatch_proto20[] = { | |
204 | {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, | |
205 | {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, | |
206 | {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, | |
207 | {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, | |
208 | {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, | |
209 | {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, | |
210 | #ifdef USE_PAM | |
211 | {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, | |
212 | {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, | |
213 | {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, | |
214 | {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, | |
215 | {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, | |
216 | {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, | |
217 | #endif | |
218 | #ifdef SSH_AUDIT_EVENTS | |
219 | {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, | |
220 | #endif | |
221 | #ifdef BSD_AUTH | |
222 | {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, | |
223 | {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, | |
224 | #endif | |
225 | #ifdef SKEY | |
226 | {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, | |
227 | {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, | |
228 | #endif | |
229 | {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, | |
230 | {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, | |
231 | #ifdef GSSAPI | |
232 | {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, | |
233 | {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, | |
234 | {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, | |
235 | {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, | |
236 | #endif | |
237 | {0, 0, NULL} | |
238 | }; | |
239 | ||
240 | struct mon_table mon_dispatch_postauth20[] = { | |
241 | {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, | |
242 | {MONITOR_REQ_SIGN, 0, mm_answer_sign}, | |
243 | {MONITOR_REQ_PTY, 0, mm_answer_pty}, | |
244 | {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, | |
245 | {MONITOR_REQ_TERM, 0, mm_answer_term}, | |
246 | #ifdef SSH_AUDIT_EVENTS | |
247 | {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, | |
248 | {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, | |
249 | #endif | |
250 | {0, 0, NULL} | |
251 | }; | |
252 | ||
253 | struct mon_table mon_dispatch_proto15[] = { | |
254 | {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, | |
255 | {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, | |
256 | {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, | |
257 | {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, | |
258 | {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, | |
259 | {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, | |
260 | {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, | |
261 | {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, | |
262 | #ifdef BSD_AUTH | |
263 | {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, | |
264 | {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, | |
265 | #endif | |
266 | #ifdef SKEY | |
267 | {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, | |
268 | {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, | |
269 | #endif | |
270 | #ifdef USE_PAM | |
271 | {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, | |
272 | {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, | |
273 | {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, | |
274 | {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, | |
275 | {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, | |
276 | {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, | |
277 | #endif | |
278 | #ifdef SSH_AUDIT_EVENTS | |
279 | {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, | |
280 | #endif | |
281 | {0, 0, NULL} | |
282 | }; | |
283 | ||
284 | struct mon_table mon_dispatch_postauth15[] = { | |
285 | {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, | |
286 | {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, | |
287 | {MONITOR_REQ_TERM, 0, mm_answer_term}, | |
288 | #ifdef SSH_AUDIT_EVENTS | |
289 | {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, | |
290 | {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, | |
291 | #endif | |
292 | {0, 0, NULL} | |
293 | }; | |
294 | ||
295 | struct mon_table *mon_dispatch; | |
296 | ||
297 | /* Specifies if a certain message is allowed at the moment */ | |
298 | ||
299 | static void | |
300 | monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) | |
301 | { | |
302 | while (ent->f != NULL) { | |
303 | if (ent->type == type) { | |
304 | ent->flags &= ~MON_PERMIT; | |
305 | ent->flags |= permit ? MON_PERMIT : 0; | |
306 | return; | |
307 | } | |
308 | ent++; | |
309 | } | |
310 | } | |
311 | ||
312 | static void | |
313 | monitor_permit_authentications(int permit) | |
314 | { | |
315 | struct mon_table *ent = mon_dispatch; | |
316 | ||
317 | while (ent->f != NULL) { | |
318 | if (ent->flags & MON_AUTH) { | |
319 | ent->flags &= ~MON_PERMIT; | |
320 | ent->flags |= permit ? MON_PERMIT : 0; | |
321 | } | |
322 | ent++; | |
323 | } | |
324 | } | |
325 | ||
326 | void | |
327 | monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) | |
328 | { | |
329 | struct mon_table *ent; | |
330 | int authenticated = 0; | |
331 | ||
332 | debug3("preauth child monitor started"); | |
333 | ||
334 | authctxt = _authctxt; | |
335 | memset(authctxt, 0, sizeof(*authctxt)); | |
336 | ||
337 | authctxt->loginmsg = &loginmsg; | |
338 | ||
339 | if (compat20) { | |
340 | mon_dispatch = mon_dispatch_proto20; | |
341 | ||
342 | /* Permit requests for moduli and signatures */ | |
343 | monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); | |
344 | monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); | |
345 | } else { | |
346 | mon_dispatch = mon_dispatch_proto15; | |
347 | ||
348 | monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); | |
349 | } | |
350 | ||
351 | /* The first few requests do not require asynchronous access */ | |
352 | while (!authenticated) { | |
353 | auth_method = "unknown"; | |
354 | authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); | |
355 | if (authenticated) { | |
356 | if (!(ent->flags & MON_AUTHDECIDE)) | |
357 | fatal("%s: unexpected authentication from %d", | |
358 | __func__, ent->type); | |
359 | if (authctxt->pw->pw_uid == 0 && | |
360 | !auth_root_allowed(auth_method)) | |
361 | authenticated = 0; | |
362 | #ifdef USE_PAM | |
363 | /* PAM needs to perform account checks after auth */ | |
364 | if (options.use_pam && authenticated) { | |
365 | Buffer m; | |
366 | ||
367 | buffer_init(&m); | |
368 | mm_request_receive_expect(pmonitor->m_sendfd, | |
369 | MONITOR_REQ_PAM_ACCOUNT, &m); | |
370 | authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); | |
371 | buffer_free(&m); | |
372 | } | |
373 | #endif | |
374 | } | |
375 | ||
376 | if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { | |
377 | auth_log(authctxt, authenticated, auth_method, | |
378 | compat20 ? " ssh2" : ""); | |
379 | if (!authenticated) | |
380 | authctxt->failures++; | |
381 | } | |
382 | } | |
383 | ||
384 | if (!authctxt->valid) | |
385 | fatal("%s: authenticated invalid user", __func__); | |
386 | if (strcmp(auth_method, "unknown") == 0) | |
387 | fatal("%s: authentication method name unknown", __func__); | |
388 | ||
389 | debug("%s: %s has been authenticated by privileged process", | |
390 | __func__, authctxt->user); | |
391 | ||
392 | mm_get_keystate(pmonitor); | |
393 | } | |
394 | ||
395 | static void | |
396 | monitor_set_child_handler(pid_t pid) | |
397 | { | |
398 | monitor_child_pid = pid; | |
399 | } | |
400 | ||
401 | static void | |
402 | monitor_child_handler(int sig) | |
403 | { | |
404 | kill(monitor_child_pid, sig); | |
405 | } | |
406 | ||
407 | void | |
408 | monitor_child_postauth(struct monitor *pmonitor) | |
409 | { | |
410 | monitor_set_child_handler(pmonitor->m_pid); | |
411 | signal(SIGHUP, &monitor_child_handler); | |
412 | signal(SIGTERM, &monitor_child_handler); | |
413 | signal(SIGINT, &monitor_child_handler); | |
414 | ||
415 | if (compat20) { | |
416 | mon_dispatch = mon_dispatch_postauth20; | |
417 | ||
418 | /* Permit requests for moduli and signatures */ | |
419 | monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); | |
420 | monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); | |
421 | monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); | |
422 | } else { | |
423 | mon_dispatch = mon_dispatch_postauth15; | |
424 | monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); | |
425 | } | |
426 | if (!no_pty_flag) { | |
427 | monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); | |
428 | monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); | |
429 | } | |
430 | ||
431 | for (;;) | |
432 | monitor_read(pmonitor, mon_dispatch, NULL); | |
433 | } | |
434 | ||
435 | void | |
436 | monitor_sync(struct monitor *pmonitor) | |
437 | { | |
438 | if (options.compression) { | |
439 | /* The member allocation is not visible, so sync it */ | |
440 | mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); | |
441 | } | |
442 | } | |
443 | ||
444 | int | |
445 | monitor_read(struct monitor *pmonitor, struct mon_table *ent, | |
446 | struct mon_table **pent) | |
447 | { | |
448 | Buffer m; | |
449 | int ret; | |
450 | u_char type; | |
451 | ||
452 | buffer_init(&m); | |
453 | ||
454 | mm_request_receive(pmonitor->m_sendfd, &m); | |
455 | type = buffer_get_char(&m); | |
456 | ||
457 | debug3("%s: checking request %d", __func__, type); | |
458 | ||
459 | while (ent->f != NULL) { | |
460 | if (ent->type == type) | |
461 | break; | |
462 | ent++; | |
463 | } | |
464 | ||
465 | if (ent->f != NULL) { | |
466 | if (!(ent->flags & MON_PERMIT)) | |
467 | fatal("%s: unpermitted request %d", __func__, | |
468 | type); | |
469 | ret = (*ent->f)(pmonitor->m_sendfd, &m); | |
470 | buffer_free(&m); | |
471 | ||
472 | /* The child may use this request only once, disable it */ | |
473 | if (ent->flags & MON_ONCE) { | |
474 | debug2("%s: %d used once, disabling now", __func__, | |
475 | type); | |
476 | ent->flags &= ~MON_PERMIT; | |
477 | } | |
478 | ||
479 | if (pent != NULL) | |
480 | *pent = ent; | |
481 | ||
482 | return ret; | |
483 | } | |
484 | ||
485 | fatal("%s: unsupported request: %d", __func__, type); | |
486 | ||
487 | /* NOTREACHED */ | |
488 | return (-1); | |
489 | } | |
490 | ||
491 | /* allowed key state */ | |
492 | static int | |
493 | monitor_allowed_key(u_char *blob, u_int bloblen) | |
494 | { | |
495 | /* make sure key is allowed */ | |
496 | if (key_blob == NULL || key_bloblen != bloblen || | |
497 | memcmp(key_blob, blob, key_bloblen)) | |
498 | return (0); | |
499 | return (1); | |
500 | } | |
501 | ||
502 | static void | |
503 | monitor_reset_key_state(void) | |
504 | { | |
505 | /* reset state */ | |
506 | if (key_blob != NULL) | |
507 | xfree(key_blob); | |
508 | if (hostbased_cuser != NULL) | |
509 | xfree(hostbased_cuser); | |
510 | if (hostbased_chost != NULL) | |
511 | xfree(hostbased_chost); | |
512 | key_blob = NULL; | |
513 | key_bloblen = 0; | |
514 | key_blobtype = MM_NOKEY; | |
515 | hostbased_cuser = NULL; | |
516 | hostbased_chost = NULL; | |
517 | } | |
518 | ||
519 | int | |
520 | mm_answer_moduli(int sock, Buffer *m) | |
521 | { | |
522 | DH *dh; | |
523 | int min, want, max; | |
524 | ||
525 | min = buffer_get_int(m); | |
526 | want = buffer_get_int(m); | |
527 | max = buffer_get_int(m); | |
528 | ||
529 | debug3("%s: got parameters: %d %d %d", | |
530 | __func__, min, want, max); | |
531 | /* We need to check here, too, in case the child got corrupted */ | |
532 | if (max < min || want < min || max < want) | |
533 | fatal("%s: bad parameters: %d %d %d", | |
534 | __func__, min, want, max); | |
535 | ||
536 | buffer_clear(m); | |
537 | ||
538 | dh = choose_dh(min, want, max); | |
539 | if (dh == NULL) { | |
540 | buffer_put_char(m, 0); | |
541 | return (0); | |
542 | } else { | |
543 | /* Send first bignum */ | |
544 | buffer_put_char(m, 1); | |
545 | buffer_put_bignum2(m, dh->p); | |
546 | buffer_put_bignum2(m, dh->g); | |
547 | ||
548 | DH_free(dh); | |
549 | } | |
550 | mm_request_send(sock, MONITOR_ANS_MODULI, m); | |
551 | return (0); | |
552 | } | |
553 | ||
554 | int | |
555 | mm_answer_sign(int sock, Buffer *m) | |
556 | { | |
557 | Key *key; | |
558 | u_char *p; | |
559 | u_char *signature; | |
560 | u_int siglen, datlen; | |
561 | int keyid; | |
562 | ||
563 | debug3("%s", __func__); | |
564 | ||
565 | keyid = buffer_get_int(m); | |
566 | p = buffer_get_string(m, &datlen); | |
567 | ||
568 | /* | |
569 | * Supported KEX types will only return SHA1 (20 byte) or | |
570 | * SHA256 (32 byte) hashes | |
571 | */ | |
572 | if (datlen != 20 && datlen != 32) | |
573 | fatal("%s: data length incorrect: %u", __func__, datlen); | |
574 | ||
575 | /* save session id, it will be passed on the first call */ | |
576 | if (session_id2_len == 0) { | |
577 | session_id2_len = datlen; | |
578 | session_id2 = xmalloc(session_id2_len); | |
579 | memcpy(session_id2, p, session_id2_len); | |
580 | } | |
581 | ||
582 | if ((key = get_hostkey_by_index(keyid)) == NULL) | |
583 | fatal("%s: no hostkey from index %d", __func__, keyid); | |
584 | if (key_sign(key, &signature, &siglen, p, datlen) < 0) | |
585 | fatal("%s: key_sign failed", __func__); | |
586 | ||
587 | debug3("%s: signature %p(%u)", __func__, signature, siglen); | |
588 | ||
589 | buffer_clear(m); | |
590 | buffer_put_string(m, signature, siglen); | |
591 | ||
592 | xfree(p); | |
593 | xfree(signature); | |
594 | ||
595 | mm_request_send(sock, MONITOR_ANS_SIGN, m); | |
596 | ||
597 | /* Turn on permissions for getpwnam */ | |
598 | monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); | |
599 | ||
600 | return (0); | |
601 | } | |
602 | ||
603 | /* Retrieves the password entry and also checks if the user is permitted */ | |
604 | ||
605 | int | |
606 | mm_answer_pwnamallow(int sock, Buffer *m) | |
607 | { | |
608 | char *username; | |
609 | struct passwd *pwent; | |
610 | int allowed = 0; | |
611 | ||
612 | debug3("%s", __func__); | |
613 | ||
614 | if (authctxt->attempt++ != 0) | |
615 | fatal("%s: multiple attempts for getpwnam", __func__); | |
616 | ||
617 | username = buffer_get_string(m, NULL); | |
618 | ||
619 | pwent = getpwnamallow(username); | |
620 | ||
621 | authctxt->user = xstrdup(username); | |
622 | setproctitle("%s [priv]", pwent ? username : "unknown"); | |
623 | xfree(username); | |
624 | ||
625 | buffer_clear(m); | |
626 | ||
627 | if (pwent == NULL) { | |
628 | buffer_put_char(m, 0); | |
629 | authctxt->pw = fakepw(); | |
630 | goto out; | |
631 | } | |
632 | ||
633 | allowed = 1; | |
634 | authctxt->pw = pwent; | |
635 | authctxt->valid = 1; | |
636 | ||
637 | buffer_put_char(m, 1); | |
638 | buffer_put_string(m, pwent, sizeof(struct passwd)); | |
639 | buffer_put_cstring(m, pwent->pw_name); | |
640 | buffer_put_cstring(m, "*"); | |
641 | buffer_put_cstring(m, pwent->pw_gecos); | |
642 | #ifdef HAVE_PW_CLASS_IN_PASSWD | |
643 | buffer_put_cstring(m, pwent->pw_class); | |
644 | #endif | |
645 | buffer_put_cstring(m, pwent->pw_dir); | |
646 | buffer_put_cstring(m, pwent->pw_shell); | |
647 | ||
648 | out: | |
649 | buffer_put_string(m, &options, sizeof(options)); | |
650 | if (options.banner != NULL) | |
651 | buffer_put_cstring(m, options.banner); | |
652 | debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); | |
653 | mm_request_send(sock, MONITOR_ANS_PWNAM, m); | |
654 | ||
655 | /* For SSHv1 allow authentication now */ | |
656 | if (!compat20) | |
657 | monitor_permit_authentications(1); | |
658 | else { | |
659 | /* Allow service/style information on the auth context */ | |
660 | monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); | |
661 | monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); | |
662 | } | |
663 | ||
664 | #ifdef USE_PAM | |
665 | if (options.use_pam) | |
666 | monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); | |
667 | #endif | |
668 | ||
669 | return (0); | |
670 | } | |
671 | ||
672 | int mm_answer_auth2_read_banner(int sock, Buffer *m) | |
673 | { | |
674 | char *banner; | |
675 | ||
676 | buffer_clear(m); | |
677 | banner = auth2_read_banner(); | |
678 | buffer_put_cstring(m, banner != NULL ? banner : ""); | |
679 | mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); | |
680 | ||
681 | if (banner != NULL) | |
682 | xfree(banner); | |
683 | ||
684 | return (0); | |
685 | } | |
686 | ||
687 | int | |
688 | mm_answer_authserv(int sock, Buffer *m) | |
689 | { | |
690 | monitor_permit_authentications(1); | |
691 | ||
692 | authctxt->service = buffer_get_string(m, NULL); | |
693 | authctxt->style = buffer_get_string(m, NULL); | |
694 | debug3("%s: service=%s, style=%s", | |
695 | __func__, authctxt->service, authctxt->style); | |
696 | ||
697 | if (strlen(authctxt->style) == 0) { | |
698 | xfree(authctxt->style); | |
699 | authctxt->style = NULL; | |
700 | } | |
701 | ||
702 | return (0); | |
703 | } | |
704 | ||
705 | int | |
706 | mm_answer_authpassword(int sock, Buffer *m) | |
707 | { | |
708 | static int call_count; | |
709 | char *passwd; | |
710 | int authenticated; | |
711 | u_int plen; | |
712 | ||
713 | passwd = buffer_get_string(m, &plen); | |
714 | /* Only authenticate if the context is valid */ | |
715 | authenticated = options.password_authentication && | |
716 | auth_password(authctxt, passwd); | |
717 | memset(passwd, 0, strlen(passwd)); | |
718 | xfree(passwd); | |
719 | ||
720 | buffer_clear(m); | |
721 | buffer_put_int(m, authenticated); | |
722 | ||
723 | debug3("%s: sending result %d", __func__, authenticated); | |
724 | mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); | |
725 | ||
726 | call_count++; | |
727 | if (plen == 0 && call_count == 1) | |
728 | auth_method = "none"; | |
729 | else | |
730 | auth_method = "password"; | |
731 | ||
732 | /* Causes monitor loop to terminate if authenticated */ | |
733 | return (authenticated); | |
734 | } | |
735 | ||
736 | #ifdef BSD_AUTH | |
737 | int | |
738 | mm_answer_bsdauthquery(int sock, Buffer *m) | |
739 | { | |
740 | char *name, *infotxt; | |
741 | u_int numprompts; | |
742 | u_int *echo_on; | |
743 | char **prompts; | |
744 | u_int success; | |
745 | ||
746 | success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, | |
747 | &prompts, &echo_on) < 0 ? 0 : 1; | |
748 | ||
749 | buffer_clear(m); | |
750 | buffer_put_int(m, success); | |
751 | if (success) | |
752 | buffer_put_cstring(m, prompts[0]); | |
753 | ||
754 | debug3("%s: sending challenge success: %u", __func__, success); | |
755 | mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); | |
756 | ||
757 | if (success) { | |
758 | xfree(name); | |
759 | xfree(infotxt); | |
760 | xfree(prompts); | |
761 | xfree(echo_on); | |
762 | } | |
763 | ||
764 | return (0); | |
765 | } | |
766 | ||
767 | int | |
768 | mm_answer_bsdauthrespond(int sock, Buffer *m) | |
769 | { | |
770 | char *response; | |
771 | int authok; | |
772 | ||
773 | if (authctxt->as == 0) | |
774 | fatal("%s: no bsd auth session", __func__); | |
775 | ||
776 | response = buffer_get_string(m, NULL); | |
777 | authok = options.challenge_response_authentication && | |
778 | auth_userresponse(authctxt->as, response, 0); | |
779 | authctxt->as = NULL; | |
780 | debug3("%s: <%s> = <%d>", __func__, response, authok); | |
781 | xfree(response); | |
782 | ||
783 | buffer_clear(m); | |
784 | buffer_put_int(m, authok); | |
785 | ||
786 | debug3("%s: sending authenticated: %d", __func__, authok); | |
787 | mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); | |
788 | ||
789 | auth_method = "bsdauth"; | |
790 | ||
791 | return (authok != 0); | |
792 | } | |
793 | #endif | |
794 | ||
795 | #ifdef SKEY | |
796 | int | |
797 | mm_answer_skeyquery(int sock, Buffer *m) | |
798 | { | |
799 | struct skey skey; | |
800 | char challenge[1024]; | |
801 | u_int success; | |
802 | ||
803 | success = _compat_skeychallenge(&skey, authctxt->user, challenge, | |
804 | sizeof(challenge)) < 0 ? 0 : 1; | |
805 | ||
806 | buffer_clear(m); | |
807 | buffer_put_int(m, success); | |
808 | if (success) | |
809 | buffer_put_cstring(m, challenge); | |
810 | ||
811 | debug3("%s: sending challenge success: %u", __func__, success); | |
812 | mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); | |
813 | ||
814 | return (0); | |
815 | } | |
816 | ||
817 | int | |
818 | mm_answer_skeyrespond(int sock, Buffer *m) | |
819 | { | |
820 | char *response; | |
821 | int authok; | |
822 | ||
823 | response = buffer_get_string(m, NULL); | |
824 | ||
825 | authok = (options.challenge_response_authentication && | |
826 | authctxt->valid && | |
827 | skey_haskey(authctxt->pw->pw_name) == 0 && | |
828 | skey_passcheck(authctxt->pw->pw_name, response) != -1); | |
829 | ||
830 | xfree(response); | |
831 | ||
832 | buffer_clear(m); | |
833 | buffer_put_int(m, authok); | |
834 | ||
835 | debug3("%s: sending authenticated: %d", __func__, authok); | |
836 | mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); | |
837 | ||
838 | auth_method = "skey"; | |
839 | ||
840 | return (authok != 0); | |
841 | } | |
842 | #endif | |
843 | ||
844 | #ifdef USE_PAM | |
845 | int | |
846 | mm_answer_pam_start(int sock, Buffer *m) | |
847 | { | |
848 | if (!options.use_pam) | |
849 | fatal("UsePAM not set, but ended up in %s anyway", __func__); | |
850 | ||
851 | start_pam(authctxt); | |
852 | ||
853 | monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); | |
854 | ||
855 | return (0); | |
856 | } | |
857 | ||
858 | int | |
859 | mm_answer_pam_account(int sock, Buffer *m) | |
860 | { | |
861 | u_int ret; | |
862 | ||
863 | if (!options.use_pam) | |
864 | fatal("UsePAM not set, but ended up in %s anyway", __func__); | |
865 | ||
866 | ret = do_pam_account(); | |
867 | ||
868 | buffer_put_int(m, ret); | |
869 | buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); | |
870 | ||
871 | mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); | |
872 | ||
873 | return (ret); | |
874 | } | |
875 | ||
876 | static void *sshpam_ctxt, *sshpam_authok; | |
877 | extern KbdintDevice sshpam_device; | |
878 | ||
879 | int | |
880 | mm_answer_pam_init_ctx(int sock, Buffer *m) | |
881 | { | |
882 | ||
883 | debug3("%s", __func__); | |
884 | authctxt->user = buffer_get_string(m, NULL); | |
885 | sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); | |
886 | sshpam_authok = NULL; | |
887 | buffer_clear(m); | |
888 | if (sshpam_ctxt != NULL) { | |
889 | monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); | |
890 | buffer_put_int(m, 1); | |
891 | } else { | |
892 | buffer_put_int(m, 0); | |
893 | } | |
894 | mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); | |
895 | return (0); | |
896 | } | |
897 | ||
898 | int | |
899 | mm_answer_pam_query(int sock, Buffer *m) | |
900 | { | |
901 | char *name, *info, **prompts; | |
902 | u_int i, num, *echo_on; | |
903 | int ret; | |
904 | ||
905 | debug3("%s", __func__); | |
906 | sshpam_authok = NULL; | |
907 | ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); | |
908 | if (ret == 0 && num == 0) | |
909 | sshpam_authok = sshpam_ctxt; | |
910 | if (num > 1 || name == NULL || info == NULL) | |
911 | ret = -1; | |
912 | buffer_clear(m); | |
913 | buffer_put_int(m, ret); | |
914 | buffer_put_cstring(m, name); | |
915 | xfree(name); | |
916 | buffer_put_cstring(m, info); | |
917 | xfree(info); | |
918 | buffer_put_int(m, num); | |
919 | for (i = 0; i < num; ++i) { | |
920 | buffer_put_cstring(m, prompts[i]); | |
921 | xfree(prompts[i]); | |
922 | buffer_put_int(m, echo_on[i]); | |
923 | } | |
924 | if (prompts != NULL) | |
925 | xfree(prompts); | |
926 | if (echo_on != NULL) | |
927 | xfree(echo_on); | |
928 | auth_method = "keyboard-interactive/pam"; | |
929 | mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); | |
930 | return (0); | |
931 | } | |
932 | ||
933 | int | |
934 | mm_answer_pam_respond(int sock, Buffer *m) | |
935 | { | |
936 | char **resp; | |
937 | u_int i, num; | |
938 | int ret; | |
939 | ||
940 | debug3("%s", __func__); | |
941 | sshpam_authok = NULL; | |
942 | num = buffer_get_int(m); | |
943 | if (num > 0) { | |
944 | resp = xcalloc(num, sizeof(char *)); | |
945 | for (i = 0; i < num; ++i) | |
946 | resp[i] = buffer_get_string(m, NULL); | |
947 | ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); | |
948 | for (i = 0; i < num; ++i) | |
949 | xfree(resp[i]); | |
950 | xfree(resp); | |
951 | } else { | |
952 | ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); | |
953 | } | |
954 | buffer_clear(m); | |
955 | buffer_put_int(m, ret); | |
956 | mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); | |
957 | auth_method = "keyboard-interactive/pam"; | |
958 | if (ret == 0) | |
959 | sshpam_authok = sshpam_ctxt; | |
960 | return (0); | |
961 | } | |
962 | ||
963 | int | |
964 | mm_answer_pam_free_ctx(int sock, Buffer *m) | |
965 | { | |
966 | ||
967 | debug3("%s", __func__); | |
968 | (sshpam_device.free_ctx)(sshpam_ctxt); | |
969 | buffer_clear(m); | |
970 | mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); | |
971 | auth_method = "keyboard-interactive/pam"; | |
972 | return (sshpam_authok == sshpam_ctxt); | |
973 | } | |
974 | #endif | |
975 | ||
976 | static void | |
977 | mm_append_debug(Buffer *m) | |
978 | { | |
979 | if (auth_debug_init && buffer_len(&auth_debug)) { | |
980 | debug3("%s: Appending debug messages for child", __func__); | |
981 | buffer_append(m, buffer_ptr(&auth_debug), | |
982 | buffer_len(&auth_debug)); | |
983 | buffer_clear(&auth_debug); | |
984 | } | |
985 | } | |
986 | ||
987 | int | |
988 | mm_answer_keyallowed(int sock, Buffer *m) | |
989 | { | |
990 | Key *key; | |
991 | char *cuser, *chost; | |
992 | u_char *blob; | |
993 | u_int bloblen; | |
994 | enum mm_keytype type = 0; | |
995 | int allowed = 0; | |
996 | ||
997 | debug3("%s entering", __func__); | |
998 | ||
999 | type = buffer_get_int(m); | |
1000 | cuser = buffer_get_string(m, NULL); | |
1001 | chost = buffer_get_string(m, NULL); | |
1002 | blob = buffer_get_string(m, &bloblen); | |
1003 | ||
1004 | key = key_from_blob(blob, bloblen); | |
1005 | ||
1006 | if ((compat20 && type == MM_RSAHOSTKEY) || | |
1007 | (!compat20 && type != MM_RSAHOSTKEY)) | |
1008 | fatal("%s: key type and protocol mismatch", __func__); | |
1009 | ||
1010 | debug3("%s: key_from_blob: %p", __func__, key); | |
1011 | ||
1012 | if (key != NULL && authctxt->valid) { | |
1013 | switch (type) { | |
1014 | case MM_USERKEY: | |
1015 | allowed = options.pubkey_authentication && | |
1016 | user_key_allowed(authctxt->pw, key); | |
1017 | auth_method = "publickey"; | |
1018 | if (options.pubkey_authentication && allowed != 1) | |
1019 | auth_clear_options(); | |
1020 | break; | |
1021 | case MM_HOSTKEY: | |
1022 | allowed = options.hostbased_authentication && | |
1023 | hostbased_key_allowed(authctxt->pw, | |
1024 | cuser, chost, key); | |
1025 | auth_method = "hostbased"; | |
1026 | break; | |
1027 | case MM_RSAHOSTKEY: | |
1028 | key->type = KEY_RSA1; /* XXX */ | |
1029 | allowed = options.rhosts_rsa_authentication && | |
1030 | auth_rhosts_rsa_key_allowed(authctxt->pw, | |
1031 | cuser, chost, key); | |
1032 | if (options.rhosts_rsa_authentication && allowed != 1) | |
1033 | auth_clear_options(); | |
1034 | auth_method = "rsa"; | |
1035 | break; | |
1036 | default: | |
1037 | fatal("%s: unknown key type %d", __func__, type); | |
1038 | break; | |
1039 | } | |
1040 | } | |
1041 | if (key != NULL) | |
1042 | key_free(key); | |
1043 | ||
1044 | /* clear temporarily storage (used by verify) */ | |
1045 | monitor_reset_key_state(); | |
1046 | ||
1047 | if (allowed) { | |
1048 | /* Save temporarily for comparison in verify */ | |
1049 | key_blob = blob; | |
1050 | key_bloblen = bloblen; | |
1051 | key_blobtype = type; | |
1052 | hostbased_cuser = cuser; | |
1053 | hostbased_chost = chost; | |
1054 | } else { | |
1055 | /* Log failed attempt */ | |
1056 | auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : ""); | |
1057 | xfree(blob); | |
1058 | xfree(cuser); | |
1059 | xfree(chost); | |
1060 | } | |
1061 | ||
1062 | debug3("%s: key %p is %s", | |
1063 | __func__, key, allowed ? "allowed" : "disallowed"); | |
1064 | ||
1065 | buffer_clear(m); | |
1066 | buffer_put_int(m, allowed); | |
1067 | buffer_put_int(m, forced_command != NULL); | |
1068 | ||
1069 | mm_append_debug(m); | |
1070 | ||
1071 | mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); | |
1072 | ||
1073 | if (type == MM_RSAHOSTKEY) | |
1074 | monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); | |
1075 | ||
1076 | return (0); | |
1077 | } | |
1078 | ||
1079 | static int | |
1080 | monitor_valid_userblob(u_char *data, u_int datalen) | |
1081 | { | |
1082 | Buffer b; | |
1083 | char *p; | |
1084 | u_int len; | |
1085 | int fail = 0; | |
1086 | ||
1087 | buffer_init(&b); | |
1088 | buffer_append(&b, data, datalen); | |
1089 | ||
1090 | if (datafellows & SSH_OLD_SESSIONID) { | |
1091 | p = buffer_ptr(&b); | |
1092 | len = buffer_len(&b); | |
1093 | if ((session_id2 == NULL) || | |
1094 | (len < session_id2_len) || | |
1095 | (memcmp(p, session_id2, session_id2_len) != 0)) | |
1096 | fail++; | |
1097 | buffer_consume(&b, session_id2_len); | |
1098 | } else { | |
1099 | p = buffer_get_string(&b, &len); | |
1100 | if ((session_id2 == NULL) || | |
1101 | (len != session_id2_len) || | |
1102 | (memcmp(p, session_id2, session_id2_len) != 0)) | |
1103 | fail++; | |
1104 | xfree(p); | |
1105 | } | |
1106 | if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) | |
1107 | fail++; | |
1108 | p = buffer_get_string(&b, NULL); | |
1109 | if (strcmp(authctxt->user, p) != 0) { | |
1110 | logit("wrong user name passed to monitor: expected %s != %.100s", | |
1111 | authctxt->user, p); | |
1112 | fail++; | |
1113 | } | |
1114 | xfree(p); | |
1115 | buffer_skip_string(&b); | |
1116 | if (datafellows & SSH_BUG_PKAUTH) { | |
1117 | if (!buffer_get_char(&b)) | |
1118 | fail++; | |
1119 | } else { | |
1120 | p = buffer_get_string(&b, NULL); | |
1121 | if (strcmp("publickey", p) != 0) | |
1122 | fail++; | |
1123 | xfree(p); | |
1124 | if (!buffer_get_char(&b)) | |
1125 | fail++; | |
1126 | buffer_skip_string(&b); | |
1127 | } | |
1128 | buffer_skip_string(&b); | |
1129 | if (buffer_len(&b) != 0) | |
1130 | fail++; | |
1131 | buffer_free(&b); | |
1132 | return (fail == 0); | |
1133 | } | |
1134 | ||
1135 | static int | |
1136 | monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, | |
1137 | char *chost) | |
1138 | { | |
1139 | Buffer b; | |
1140 | char *p; | |
1141 | u_int len; | |
1142 | int fail = 0; | |
1143 | ||
1144 | buffer_init(&b); | |
1145 | buffer_append(&b, data, datalen); | |
1146 | ||
1147 | p = buffer_get_string(&b, &len); | |
1148 | if ((session_id2 == NULL) || | |
1149 | (len != session_id2_len) || | |
1150 | (memcmp(p, session_id2, session_id2_len) != 0)) | |
1151 | fail++; | |
1152 | xfree(p); | |
1153 | ||
1154 | if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) | |
1155 | fail++; | |
1156 | p = buffer_get_string(&b, NULL); | |
1157 | if (strcmp(authctxt->user, p) != 0) { | |
1158 | logit("wrong user name passed to monitor: expected %s != %.100s", | |
1159 | authctxt->user, p); | |
1160 | fail++; | |
1161 | } | |
1162 | xfree(p); | |
1163 | buffer_skip_string(&b); /* service */ | |
1164 | p = buffer_get_string(&b, NULL); | |
1165 | if (strcmp(p, "hostbased") != 0) | |
1166 | fail++; | |
1167 | xfree(p); | |
1168 | buffer_skip_string(&b); /* pkalg */ | |
1169 | buffer_skip_string(&b); /* pkblob */ | |
1170 | ||
1171 | /* verify client host, strip trailing dot if necessary */ | |
1172 | p = buffer_get_string(&b, NULL); | |
1173 | if (((len = strlen(p)) > 0) && p[len - 1] == '.') | |
1174 | p[len - 1] = '\0'; | |
1175 | if (strcmp(p, chost) != 0) | |
1176 | fail++; | |
1177 | xfree(p); | |
1178 | ||
1179 | /* verify client user */ | |
1180 | p = buffer_get_string(&b, NULL); | |
1181 | if (strcmp(p, cuser) != 0) | |
1182 | fail++; | |
1183 | xfree(p); | |
1184 | ||
1185 | if (buffer_len(&b) != 0) | |
1186 | fail++; | |
1187 | buffer_free(&b); | |
1188 | return (fail == 0); | |
1189 | } | |
1190 | ||
1191 | int | |
1192 | mm_answer_keyverify(int sock, Buffer *m) | |
1193 | { | |
1194 | Key *key; | |
1195 | u_char *signature, *data, *blob; | |
1196 | u_int signaturelen, datalen, bloblen; | |
1197 | int verified = 0; | |
1198 | int valid_data = 0; | |
1199 | ||
1200 | blob = buffer_get_string(m, &bloblen); | |
1201 | signature = buffer_get_string(m, &signaturelen); | |
1202 | data = buffer_get_string(m, &datalen); | |
1203 | ||
1204 | if (hostbased_cuser == NULL || hostbased_chost == NULL || | |
1205 | !monitor_allowed_key(blob, bloblen)) | |
1206 | fatal("%s: bad key, not previously allowed", __func__); | |
1207 | ||
1208 | key = key_from_blob(blob, bloblen); | |
1209 | if (key == NULL) | |
1210 | fatal("%s: bad public key blob", __func__); | |
1211 | ||
1212 | switch (key_blobtype) { | |
1213 | case MM_USERKEY: | |
1214 | valid_data = monitor_valid_userblob(data, datalen); | |
1215 | break; | |
1216 | case MM_HOSTKEY: | |
1217 | valid_data = monitor_valid_hostbasedblob(data, datalen, | |
1218 | hostbased_cuser, hostbased_chost); | |
1219 | break; | |
1220 | default: | |
1221 | valid_data = 0; | |
1222 | break; | |
1223 | } | |
1224 | if (!valid_data) | |
1225 | fatal("%s: bad signature data blob", __func__); | |
1226 | ||
1227 | verified = key_verify(key, signature, signaturelen, data, datalen); | |
1228 | debug3("%s: key %p signature %s", | |
1229 | __func__, key, (verified == 1) ? "verified" : "unverified"); | |
1230 | ||
1231 | key_free(key); | |
1232 | xfree(blob); | |
1233 | xfree(signature); | |
1234 | xfree(data); | |
1235 | ||
1236 | auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; | |
1237 | ||
1238 | monitor_reset_key_state(); | |
1239 | ||
1240 | buffer_clear(m); | |
1241 | buffer_put_int(m, verified); | |
1242 | mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); | |
1243 | ||
1244 | return (verified == 1); | |
1245 | } | |
1246 | ||
1247 | static void | |
1248 | mm_record_login(Session *s, struct passwd *pw) | |
1249 | { | |
1250 | socklen_t fromlen; | |
1251 | struct sockaddr_storage from; | |
1252 | ||
1253 | /* | |
1254 | * Get IP address of client. If the connection is not a socket, let | |
1255 | * the address be 0.0.0.0. | |
1256 | */ | |
1257 | memset(&from, 0, sizeof(from)); | |
1258 | fromlen = sizeof(from); | |
1259 | if (packet_connection_is_on_socket()) { | |
1260 | if (getpeername(packet_get_connection_in(), | |
1261 | (struct sockaddr *)&from, &fromlen) < 0) { | |
1262 | debug("getpeername: %.100s", strerror(errno)); | |
1263 | cleanup_exit(255); | |
1264 | } | |
1265 | } | |
1266 | /* Record that there was a login on that tty from the remote host. */ | |
1267 | record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, | |
1268 | get_remote_name_or_ip(utmp_len, options.use_dns), | |
1269 | (struct sockaddr *)&from, fromlen); | |
1270 | } | |
1271 | ||
1272 | static void | |
1273 | mm_session_close(Session *s) | |
1274 | { | |
1275 | debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); | |
1276 | if (s->ttyfd != -1) { | |
1277 | debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); | |
1278 | session_pty_cleanup2(s); | |
1279 | } | |
1280 | session_unused(s->self); | |
1281 | } | |
1282 | ||
1283 | int | |
1284 | mm_answer_pty(int sock, Buffer *m) | |
1285 | { | |
1286 | extern struct monitor *pmonitor; | |
1287 | Session *s; | |
1288 | int res, fd0; | |
1289 | ||
1290 | debug3("%s entering", __func__); | |
1291 | ||
1292 | buffer_clear(m); | |
1293 | s = session_new(); | |
1294 | if (s == NULL) | |
1295 | goto error; | |
1296 | s->authctxt = authctxt; | |
1297 | s->pw = authctxt->pw; | |
1298 | s->pid = pmonitor->m_pid; | |
1299 | res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); | |
1300 | if (res == 0) | |
1301 | goto error; | |
1302 | pty_setowner(authctxt->pw, s->tty); | |
1303 | ||
1304 | buffer_put_int(m, 1); | |
1305 | buffer_put_cstring(m, s->tty); | |
1306 | ||
1307 | /* We need to trick ttyslot */ | |
1308 | if (dup2(s->ttyfd, 0) == -1) | |
1309 | fatal("%s: dup2", __func__); | |
1310 | ||
1311 | mm_record_login(s, authctxt->pw); | |
1312 | ||
1313 | /* Now we can close the file descriptor again */ | |
1314 | close(0); | |
1315 | ||
1316 | /* send messages generated by record_login */ | |
1317 | buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); | |
1318 | buffer_clear(&loginmsg); | |
1319 | ||
1320 | mm_request_send(sock, MONITOR_ANS_PTY, m); | |
1321 | ||
1322 | if (mm_send_fd(sock, s->ptyfd) == -1 || | |
1323 | mm_send_fd(sock, s->ttyfd) == -1) | |
1324 | fatal("%s: send fds failed", __func__); | |
1325 | ||
1326 | /* make sure nothing uses fd 0 */ | |
1327 | if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) | |
1328 | fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); | |
1329 | if (fd0 != 0) | |
1330 | error("%s: fd0 %d != 0", __func__, fd0); | |
1331 | ||
1332 | /* slave is not needed */ | |
1333 | close(s->ttyfd); | |
1334 | s->ttyfd = s->ptyfd; | |
1335 | /* no need to dup() because nobody closes ptyfd */ | |
1336 | s->ptymaster = s->ptyfd; | |
1337 | ||
1338 | debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); | |
1339 | ||
1340 | return (0); | |
1341 | ||
1342 | error: | |
1343 | if (s != NULL) | |
1344 | mm_session_close(s); | |
1345 | buffer_put_int(m, 0); | |
1346 | mm_request_send(sock, MONITOR_ANS_PTY, m); | |
1347 | return (0); | |
1348 | } | |
1349 | ||
1350 | int | |
1351 | mm_answer_pty_cleanup(int sock, Buffer *m) | |
1352 | { | |
1353 | Session *s; | |
1354 | char *tty; | |
1355 | ||
1356 | debug3("%s entering", __func__); | |
1357 | ||
1358 | tty = buffer_get_string(m, NULL); | |
1359 | if ((s = session_by_tty(tty)) != NULL) | |
1360 | mm_session_close(s); | |
1361 | buffer_clear(m); | |
1362 | xfree(tty); | |
1363 | return (0); | |
1364 | } | |
1365 | ||
1366 | int | |
1367 | mm_answer_sesskey(int sock, Buffer *m) | |
1368 | { | |
1369 | BIGNUM *p; | |
1370 | int rsafail; | |
1371 | ||
1372 | /* Turn off permissions */ | |
1373 | monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); | |
1374 | ||
1375 | if ((p = BN_new()) == NULL) | |
1376 | fatal("%s: BN_new", __func__); | |
1377 | ||
1378 | buffer_get_bignum2(m, p); | |
1379 | ||
1380 | rsafail = ssh1_session_key(p); | |
1381 | ||
1382 | buffer_clear(m); | |
1383 | buffer_put_int(m, rsafail); | |
1384 | buffer_put_bignum2(m, p); | |
1385 | ||
1386 | BN_clear_free(p); | |
1387 | ||
1388 | mm_request_send(sock, MONITOR_ANS_SESSKEY, m); | |
1389 | ||
1390 | /* Turn on permissions for sessid passing */ | |
1391 | monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); | |
1392 | ||
1393 | return (0); | |
1394 | } | |
1395 | ||
1396 | int | |
1397 | mm_answer_sessid(int sock, Buffer *m) | |
1398 | { | |
1399 | int i; | |
1400 | ||
1401 | debug3("%s entering", __func__); | |
1402 | ||
1403 | if (buffer_len(m) != 16) | |
1404 | fatal("%s: bad ssh1 session id", __func__); | |
1405 | for (i = 0; i < 16; i++) | |
1406 | session_id[i] = buffer_get_char(m); | |
1407 | ||
1408 | /* Turn on permissions for getpwnam */ | |
1409 | monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); | |
1410 | ||
1411 | return (0); | |
1412 | } | |
1413 | ||
1414 | int | |
1415 | mm_answer_rsa_keyallowed(int sock, Buffer *m) | |
1416 | { | |
1417 | BIGNUM *client_n; | |
1418 | Key *key = NULL; | |
1419 | u_char *blob = NULL; | |
1420 | u_int blen = 0; | |
1421 | int allowed = 0; | |
1422 | ||
1423 | debug3("%s entering", __func__); | |
1424 | ||
1425 | auth_method = "rsa"; | |
1426 | if (options.rsa_authentication && authctxt->valid) { | |
1427 | if ((client_n = BN_new()) == NULL) | |
1428 | fatal("%s: BN_new", __func__); | |
1429 | buffer_get_bignum2(m, client_n); | |
1430 | allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); | |
1431 | BN_clear_free(client_n); | |
1432 | } | |
1433 | buffer_clear(m); | |
1434 | buffer_put_int(m, allowed); | |
1435 | buffer_put_int(m, forced_command != NULL); | |
1436 | ||
1437 | /* clear temporarily storage (used by generate challenge) */ | |
1438 | monitor_reset_key_state(); | |
1439 | ||
1440 | if (allowed && key != NULL) { | |
1441 | key->type = KEY_RSA; /* cheat for key_to_blob */ | |
1442 | if (key_to_blob(key, &blob, &blen) == 0) | |
1443 | fatal("%s: key_to_blob failed", __func__); | |
1444 | buffer_put_string(m, blob, blen); | |
1445 | ||
1446 | /* Save temporarily for comparison in verify */ | |
1447 | key_blob = blob; | |
1448 | key_bloblen = blen; | |
1449 | key_blobtype = MM_RSAUSERKEY; | |
1450 | } | |
1451 | if (key != NULL) | |
1452 | key_free(key); | |
1453 | ||
1454 | mm_append_debug(m); | |
1455 | ||
1456 | mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); | |
1457 | ||
1458 | monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); | |
1459 | monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); | |
1460 | return (0); | |
1461 | } | |
1462 | ||
1463 | int | |
1464 | mm_answer_rsa_challenge(int sock, Buffer *m) | |
1465 | { | |
1466 | Key *key = NULL; | |
1467 | u_char *blob; | |
1468 | u_int blen; | |
1469 | ||
1470 | debug3("%s entering", __func__); | |
1471 | ||
1472 | if (!authctxt->valid) | |
1473 | fatal("%s: authctxt not valid", __func__); | |
1474 | blob = buffer_get_string(m, &blen); | |
1475 | if (!monitor_allowed_key(blob, blen)) | |
1476 | fatal("%s: bad key, not previously allowed", __func__); | |
1477 | if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) | |
1478 | fatal("%s: key type mismatch", __func__); | |
1479 | if ((key = key_from_blob(blob, blen)) == NULL) | |
1480 | fatal("%s: received bad key", __func__); | |
1481 | ||
1482 | if (ssh1_challenge) | |
1483 | BN_clear_free(ssh1_challenge); | |
1484 | ssh1_challenge = auth_rsa_generate_challenge(key); | |
1485 | ||
1486 | buffer_clear(m); | |
1487 | buffer_put_bignum2(m, ssh1_challenge); | |
1488 | ||
1489 | debug3("%s sending reply", __func__); | |
1490 | mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); | |
1491 | ||
1492 | monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); | |
1493 | ||
1494 | xfree(blob); | |
1495 | key_free(key); | |
1496 | return (0); | |
1497 | } | |
1498 | ||
1499 | int | |
1500 | mm_answer_rsa_response(int sock, Buffer *m) | |
1501 | { | |
1502 | Key *key = NULL; | |
1503 | u_char *blob, *response; | |
1504 | u_int blen, len; | |
1505 | int success; | |
1506 | ||
1507 | debug3("%s entering", __func__); | |
1508 | ||
1509 | if (!authctxt->valid) | |
1510 | fatal("%s: authctxt not valid", __func__); | |
1511 | if (ssh1_challenge == NULL) | |
1512 | fatal("%s: no ssh1_challenge", __func__); | |
1513 | ||
1514 | blob = buffer_get_string(m, &blen); | |
1515 | if (!monitor_allowed_key(blob, blen)) | |
1516 | fatal("%s: bad key, not previously allowed", __func__); | |
1517 | if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) | |
1518 | fatal("%s: key type mismatch: %d", __func__, key_blobtype); | |
1519 | if ((key = key_from_blob(blob, blen)) == NULL) | |
1520 | fatal("%s: received bad key", __func__); | |
1521 | response = buffer_get_string(m, &len); | |
1522 | if (len != 16) | |
1523 | fatal("%s: received bad response to challenge", __func__); | |
1524 | success = auth_rsa_verify_response(key, ssh1_challenge, response); | |
1525 | ||
1526 | xfree(blob); | |
1527 | key_free(key); | |
1528 | xfree(response); | |
1529 | ||
1530 | auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; | |
1531 | ||
1532 | /* reset state */ | |
1533 | BN_clear_free(ssh1_challenge); | |
1534 | ssh1_challenge = NULL; | |
1535 | monitor_reset_key_state(); | |
1536 | ||
1537 | buffer_clear(m); | |
1538 | buffer_put_int(m, success); | |
1539 | mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); | |
1540 | ||
1541 | return (success); | |
1542 | } | |
1543 | ||
1544 | int | |
1545 | mm_answer_term(int sock, Buffer *req) | |
1546 | { | |
1547 | extern struct monitor *pmonitor; | |
1548 | int res, status; | |
1549 | ||
1550 | debug3("%s: tearing down sessions", __func__); | |
1551 | ||
1552 | /* The child is terminating */ | |
1553 | session_destroy_all(&mm_session_close); | |
1554 | ||
1555 | #ifdef USE_PAM | |
1556 | if (options.use_pam) | |
1557 | sshpam_cleanup(); | |
1558 | #endif | |
1559 | ||
1560 | while (waitpid(pmonitor->m_pid, &status, 0) == -1) | |
1561 | if (errno != EINTR) | |
1562 | exit(1); | |
1563 | ||
1564 | res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; | |
1565 | ||
1566 | /* Terminate process */ | |
1567 | exit(res); | |
1568 | } | |
1569 | ||
1570 | #ifdef SSH_AUDIT_EVENTS | |
1571 | /* Report that an audit event occurred */ | |
1572 | int | |
1573 | mm_answer_audit_event(int socket, Buffer *m) | |
1574 | { | |
1575 | ssh_audit_event_t event; | |
1576 | ||
1577 | debug3("%s entering", __func__); | |
1578 | ||
1579 | event = buffer_get_int(m); | |
1580 | switch(event) { | |
1581 | case SSH_AUTH_FAIL_PUBKEY: | |
1582 | case SSH_AUTH_FAIL_HOSTBASED: | |
1583 | case SSH_AUTH_FAIL_GSSAPI: | |
1584 | case SSH_LOGIN_EXCEED_MAXTRIES: | |
1585 | case SSH_LOGIN_ROOT_DENIED: | |
1586 | case SSH_CONNECTION_CLOSE: | |
1587 | case SSH_INVALID_USER: | |
1588 | audit_event(event); | |
1589 | break; | |
1590 | default: | |
1591 | fatal("Audit event type %d not permitted", event); | |
1592 | } | |
1593 | ||
1594 | return (0); | |
1595 | } | |
1596 | ||
1597 | int | |
1598 | mm_answer_audit_command(int socket, Buffer *m) | |
1599 | { | |
1600 | u_int len; | |
1601 | char *cmd; | |
1602 | ||
1603 | debug3("%s entering", __func__); | |
1604 | cmd = buffer_get_string(m, &len); | |
1605 | /* sanity check command, if so how? */ | |
1606 | audit_run_command(cmd); | |
1607 | xfree(cmd); | |
1608 | return (0); | |
1609 | } | |
1610 | #endif /* SSH_AUDIT_EVENTS */ | |
1611 | ||
1612 | void | |
1613 | monitor_apply_keystate(struct monitor *pmonitor) | |
1614 | { | |
1615 | if (compat20) { | |
1616 | set_newkeys(MODE_IN); | |
1617 | set_newkeys(MODE_OUT); | |
1618 | } else { | |
1619 | packet_set_protocol_flags(child_state.ssh1protoflags); | |
1620 | packet_set_encryption_key(child_state.ssh1key, | |
1621 | child_state.ssh1keylen, child_state.ssh1cipher); | |
1622 | xfree(child_state.ssh1key); | |
1623 | } | |
1624 | ||
1625 | /* for rc4 and other stateful ciphers */ | |
1626 | packet_set_keycontext(MODE_OUT, child_state.keyout); | |
1627 | xfree(child_state.keyout); | |
1628 | packet_set_keycontext(MODE_IN, child_state.keyin); | |
1629 | xfree(child_state.keyin); | |
1630 | ||
1631 | if (!compat20) { | |
1632 | packet_set_iv(MODE_OUT, child_state.ivout); | |
1633 | xfree(child_state.ivout); | |
1634 | packet_set_iv(MODE_IN, child_state.ivin); | |
1635 | xfree(child_state.ivin); | |
1636 | } | |
1637 | ||
1638 | memcpy(&incoming_stream, &child_state.incoming, | |
1639 | sizeof(incoming_stream)); | |
1640 | memcpy(&outgoing_stream, &child_state.outgoing, | |
1641 | sizeof(outgoing_stream)); | |
1642 | ||
1643 | /* Update with new address */ | |
1644 | if (options.compression) | |
1645 | mm_init_compression(pmonitor->m_zlib); | |
1646 | ||
1647 | /* Network I/O buffers */ | |
1648 | /* XXX inefficient for large buffers, need: buffer_init_from_string */ | |
1649 | buffer_clear(&input); | |
1650 | buffer_append(&input, child_state.input, child_state.ilen); | |
1651 | memset(child_state.input, 0, child_state.ilen); | |
1652 | xfree(child_state.input); | |
1653 | ||
1654 | buffer_clear(&output); | |
1655 | buffer_append(&output, child_state.output, child_state.olen); | |
1656 | memset(child_state.output, 0, child_state.olen); | |
1657 | xfree(child_state.output); | |
1658 | } | |
1659 | ||
1660 | static Kex * | |
1661 | mm_get_kex(Buffer *m) | |
1662 | { | |
1663 | Kex *kex; | |
1664 | void *blob; | |
1665 | u_int bloblen; | |
1666 | ||
1667 | kex = xcalloc(1, sizeof(*kex)); | |
1668 | kex->session_id = buffer_get_string(m, &kex->session_id_len); | |
1669 | if ((session_id2 == NULL) || | |
1670 | (kex->session_id_len != session_id2_len) || | |
1671 | (memcmp(kex->session_id, session_id2, session_id2_len) != 0)) | |
1672 | fatal("mm_get_get: internal error: bad session id"); | |
1673 | kex->we_need = buffer_get_int(m); | |
1674 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; | |
1675 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; | |
1676 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; | |
1677 | kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; | |
1678 | kex->server = 1; | |
1679 | kex->hostkey_type = buffer_get_int(m); | |
1680 | kex->kex_type = buffer_get_int(m); | |
1681 | blob = buffer_get_string(m, &bloblen); | |
1682 | buffer_init(&kex->my); | |
1683 | buffer_append(&kex->my, blob, bloblen); | |
1684 | xfree(blob); | |
1685 | blob = buffer_get_string(m, &bloblen); | |
1686 | buffer_init(&kex->peer); | |
1687 | buffer_append(&kex->peer, blob, bloblen); | |
1688 | xfree(blob); | |
1689 | kex->done = 1; | |
1690 | kex->flags = buffer_get_int(m); | |
1691 | kex->client_version_string = buffer_get_string(m, NULL); | |
1692 | kex->server_version_string = buffer_get_string(m, NULL); | |
1693 | kex->load_host_key=&get_hostkey_by_type; | |
1694 | kex->host_key_index=&get_hostkey_index; | |
1695 | ||
1696 | return (kex); | |
1697 | } | |
1698 | ||
1699 | /* This function requries careful sanity checking */ | |
1700 | ||
1701 | void | |
1702 | mm_get_keystate(struct monitor *pmonitor) | |
1703 | { | |
1704 | Buffer m; | |
1705 | u_char *blob, *p; | |
1706 | u_int bloblen, plen; | |
1707 | u_int32_t seqnr, packets; | |
1708 | u_int64_t blocks; | |
1709 | ||
1710 | debug3("%s: Waiting for new keys", __func__); | |
1711 | ||
1712 | buffer_init(&m); | |
1713 | mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); | |
1714 | if (!compat20) { | |
1715 | child_state.ssh1protoflags = buffer_get_int(&m); | |
1716 | child_state.ssh1cipher = buffer_get_int(&m); | |
1717 | child_state.ssh1key = buffer_get_string(&m, | |
1718 | &child_state.ssh1keylen); | |
1719 | child_state.ivout = buffer_get_string(&m, | |
1720 | &child_state.ivoutlen); | |
1721 | child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); | |
1722 | goto skip; | |
1723 | } else { | |
1724 | /* Get the Kex for rekeying */ | |
1725 | *pmonitor->m_pkex = mm_get_kex(&m); | |
1726 | } | |
1727 | ||
1728 | blob = buffer_get_string(&m, &bloblen); | |
1729 | current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); | |
1730 | xfree(blob); | |
1731 | ||
1732 | debug3("%s: Waiting for second key", __func__); | |
1733 | blob = buffer_get_string(&m, &bloblen); | |
1734 | current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); | |
1735 | xfree(blob); | |
1736 | ||
1737 | /* Now get sequence numbers for the packets */ | |
1738 | seqnr = buffer_get_int(&m); | |
1739 | blocks = buffer_get_int64(&m); | |
1740 | packets = buffer_get_int(&m); | |
1741 | packet_set_state(MODE_OUT, seqnr, blocks, packets); | |
1742 | seqnr = buffer_get_int(&m); | |
1743 | blocks = buffer_get_int64(&m); | |
1744 | packets = buffer_get_int(&m); | |
1745 | packet_set_state(MODE_IN, seqnr, blocks, packets); | |
1746 | ||
1747 | skip: | |
1748 | /* Get the key context */ | |
1749 | child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); | |
1750 | child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); | |
1751 | ||
1752 | debug3("%s: Getting compression state", __func__); | |
1753 | /* Get compression state */ | |
1754 | p = buffer_get_string(&m, &plen); | |
1755 | if (plen != sizeof(child_state.outgoing)) | |
1756 | fatal("%s: bad request size", __func__); | |
1757 | memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); | |
1758 | xfree(p); | |
1759 | ||
1760 | p = buffer_get_string(&m, &plen); | |
1761 | if (plen != sizeof(child_state.incoming)) | |
1762 | fatal("%s: bad request size", __func__); | |
1763 | memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); | |
1764 | xfree(p); | |
1765 | ||
1766 | /* Network I/O buffers */ | |
1767 | debug3("%s: Getting Network I/O buffers", __func__); | |
1768 | child_state.input = buffer_get_string(&m, &child_state.ilen); | |
1769 | child_state.output = buffer_get_string(&m, &child_state.olen); | |
1770 | ||
1771 | buffer_free(&m); | |
1772 | } | |
1773 | ||
1774 | ||
1775 | /* Allocation functions for zlib */ | |
1776 | void * | |
1777 | mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) | |
1778 | { | |
1779 | size_t len = (size_t) size * ncount; | |
1780 | void *address; | |
1781 | ||
1782 | if (len == 0 || ncount > SIZE_T_MAX / size) | |
1783 | fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); | |
1784 | ||
1785 | address = mm_malloc(mm, len); | |
1786 | ||
1787 | return (address); | |
1788 | } | |
1789 | ||
1790 | void | |
1791 | mm_zfree(struct mm_master *mm, void *address) | |
1792 | { | |
1793 | mm_free(mm, address); | |
1794 | } | |
1795 | ||
1796 | void | |
1797 | mm_init_compression(struct mm_master *mm) | |
1798 | { | |
1799 | outgoing_stream.zalloc = (alloc_func)mm_zalloc; | |
1800 | outgoing_stream.zfree = (free_func)mm_zfree; | |
1801 | outgoing_stream.opaque = mm; | |
1802 | ||
1803 | incoming_stream.zalloc = (alloc_func)mm_zalloc; | |
1804 | incoming_stream.zfree = (free_func)mm_zfree; | |
1805 | incoming_stream.opaque = mm; | |
1806 | } | |
1807 | ||
1808 | /* XXX */ | |
1809 | ||
1810 | #define FD_CLOSEONEXEC(x) do { \ | |
1811 | if (fcntl(x, F_SETFD, 1) == -1) \ | |
1812 | fatal("fcntl(%d, F_SETFD)", x); \ | |
1813 | } while (0) | |
1814 | ||
1815 | static void | |
1816 | monitor_socketpair(int *pair) | |
1817 | { | |
1818 | #ifdef HAVE_SOCKETPAIR | |
1819 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) | |
1820 | fatal("%s: socketpair", __func__); | |
1821 | #else | |
1822 | fatal("%s: UsePrivilegeSeparation=yes not supported", | |
1823 | __func__); | |
1824 | #endif | |
1825 | FD_CLOSEONEXEC(pair[0]); | |
1826 | FD_CLOSEONEXEC(pair[1]); | |
1827 | } | |
1828 | ||
1829 | #define MM_MEMSIZE 65536 | |
1830 | ||
1831 | struct monitor * | |
1832 | monitor_init(void) | |
1833 | { | |
1834 | struct monitor *mon; | |
1835 | int pair[2]; | |
1836 | ||
1837 | mon = xcalloc(1, sizeof(*mon)); | |
1838 | ||
1839 | monitor_socketpair(pair); | |
1840 | ||
1841 | mon->m_recvfd = pair[0]; | |
1842 | mon->m_sendfd = pair[1]; | |
1843 | ||
1844 | /* Used to share zlib space across processes */ | |
1845 | if (options.compression) { | |
1846 | mon->m_zback = mm_create(NULL, MM_MEMSIZE); | |
1847 | mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); | |
1848 | ||
1849 | /* Compression needs to share state across borders */ | |
1850 | mm_init_compression(mon->m_zlib); | |
1851 | } | |
1852 | ||
1853 | return mon; | |
1854 | } | |
1855 | ||
1856 | void | |
1857 | monitor_reinit(struct monitor *mon) | |
1858 | { | |
1859 | int pair[2]; | |
1860 | ||
1861 | monitor_socketpair(pair); | |
1862 | ||
1863 | mon->m_recvfd = pair[0]; | |
1864 | mon->m_sendfd = pair[1]; | |
1865 | } | |
1866 | ||
1867 | #ifdef GSSAPI | |
1868 | int | |
1869 | mm_answer_gss_setup_ctx(int sock, Buffer *m) | |
1870 | { | |
1871 | gss_OID_desc goid; | |
1872 | OM_uint32 major; | |
1873 | u_int len; | |
1874 | ||
1875 | goid.elements = buffer_get_string(m, &len); | |
1876 | goid.length = len; | |
1877 | ||
1878 | major = ssh_gssapi_server_ctx(&gsscontext, &goid); | |
1879 | ||
1880 | xfree(goid.elements); | |
1881 | ||
1882 | buffer_clear(m); | |
1883 | buffer_put_int(m, major); | |
1884 | ||
1885 | mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); | |
1886 | ||
1887 | /* Now we have a context, enable the step */ | |
1888 | monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); | |
1889 | ||
1890 | return (0); | |
1891 | } | |
1892 | ||
1893 | int | |
1894 | mm_answer_gss_accept_ctx(int sock, Buffer *m) | |
1895 | { | |
1896 | gss_buffer_desc in; | |
1897 | gss_buffer_desc out = GSS_C_EMPTY_BUFFER; | |
1898 | OM_uint32 major, minor; | |
1899 | OM_uint32 flags = 0; /* GSI needs this */ | |
1900 | u_int len; | |
1901 | ||
1902 | in.value = buffer_get_string(m, &len); | |
1903 | in.length = len; | |
1904 | major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); | |
1905 | xfree(in.value); | |
1906 | ||
1907 | buffer_clear(m); | |
1908 | buffer_put_int(m, major); | |
1909 | buffer_put_string(m, out.value, out.length); | |
1910 | buffer_put_int(m, flags); | |
1911 | mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); | |
1912 | ||
1913 | gss_release_buffer(&minor, &out); | |
1914 | ||
1915 | if (major == GSS_S_COMPLETE) { | |
1916 | monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); | |
1917 | monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); | |
1918 | monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); | |
1919 | } | |
1920 | return (0); | |
1921 | } | |
1922 | ||
1923 | int | |
1924 | mm_answer_gss_checkmic(int sock, Buffer *m) | |
1925 | { | |
1926 | gss_buffer_desc gssbuf, mic; | |
1927 | OM_uint32 ret; | |
1928 | u_int len; | |
1929 | ||
1930 | gssbuf.value = buffer_get_string(m, &len); | |
1931 | gssbuf.length = len; | |
1932 | mic.value = buffer_get_string(m, &len); | |
1933 | mic.length = len; | |
1934 | ||
1935 | ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); | |
1936 | ||
1937 | xfree(gssbuf.value); | |
1938 | xfree(mic.value); | |
1939 | ||
1940 | buffer_clear(m); | |
1941 | buffer_put_int(m, ret); | |
1942 | ||
1943 | mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); | |
1944 | ||
1945 | if (!GSS_ERROR(ret)) | |
1946 | monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); | |
1947 | ||
1948 | return (0); | |
1949 | } | |
1950 | ||
1951 | int | |
1952 | mm_answer_gss_userok(int sock, Buffer *m) | |
1953 | { | |
1954 | int authenticated; | |
1955 | ||
1956 | authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); | |
1957 | ||
1958 | buffer_clear(m); | |
1959 | buffer_put_int(m, authenticated); | |
1960 | ||
1961 | debug3("%s: sending result %d", __func__, authenticated); | |
1962 | mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); | |
1963 | ||
1964 | auth_method = "gssapi-with-mic"; | |
1965 | ||
1966 | /* Monitor loop will terminate if authenticated */ | |
1967 | return (authenticated); | |
1968 | } | |
1969 | #endif /* GSSAPI */ |