1 /* $OpenBSD: monitor_wrap.c,v 1.130 2024/05/17 00:30:24 djm 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 <sys/types.h>
29 #include <sys/uio.h>
30 #include <sys/queue.h>
31
32 #include <errno.h>
33 #include <pwd.h>
34 #include <signal.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <stdarg.h>
38 #include <unistd.h>
39
40 #ifdef WITH_OPENSSL
41 #include <openssl/bn.h>
42 #include <openssl/dh.h>
43 #endif
44
45 #include "xmalloc.h"
46 #include "ssh.h"
47 #ifdef WITH_OPENSSL
48 #include "dh.h"
49 #endif
50 #include "sshbuf.h"
51 #include "sshkey.h"
52 #include "cipher.h"
53 #include "kex.h"
54 #include "hostfile.h"
55 #include "auth.h"
56 #include "auth-options.h"
57 #include "packet.h"
58 #include "mac.h"
59 #include "log.h"
60 #include "monitor.h"
61 #ifdef GSSAPI
62 #include "ssh-gss.h"
63 #endif
64 #include "atomicio.h"
65 #include "monitor_fdpass.h"
66 #include "misc.h"
67
68 #include "channels.h"
69 #include "session.h"
70 #include "servconf.h"
71 #include "monitor_wrap.h"
72
73 #include "ssherr.h"
74
75 /* Imports */
76 extern struct monitor *pmonitor;
77 extern struct sshbuf *loginmsg;
78 extern ServerOptions options;
79
80 void
mm_log_handler(LogLevel level,int forced,const char * msg,void * ctx)81 mm_log_handler(LogLevel level, int forced, const char *msg, void *ctx)
82 {
83 struct sshbuf *log_msg;
84 struct monitor *mon = (struct monitor *)ctx;
85 int r;
86 size_t len;
87
88 if (mon->m_log_sendfd == -1)
89 fatal_f("no log channel");
90
91 if ((log_msg = sshbuf_new()) == NULL)
92 fatal_f("sshbuf_new failed");
93
94 if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */
95 (r = sshbuf_put_u32(log_msg, level)) != 0 ||
96 (r = sshbuf_put_u32(log_msg, forced)) != 0 ||
97 (r = sshbuf_put_cstring(log_msg, msg)) != 0)
98 fatal_fr(r, "assemble");
99 if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff)
100 fatal_f("bad length %zu", len);
101 POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4);
102 if (atomicio(vwrite, mon->m_log_sendfd,
103 sshbuf_mutable_ptr(log_msg), len) != len)
104 fatal_f("write: %s", strerror(errno));
105 sshbuf_free(log_msg);
106 }
107
108 int
mm_is_monitor(void)109 mm_is_monitor(void)
110 {
111 /*
112 * m_pid is only set in the privileged part, and
113 * points to the unprivileged child.
114 */
115 return (pmonitor && pmonitor->m_pid > 0);
116 }
117
118 void
mm_request_send(int sock,enum monitor_reqtype type,struct sshbuf * m)119 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m)
120 {
121 size_t mlen = sshbuf_len(m);
122 u_char buf[5];
123
124 debug3_f("entering, type %d", type);
125
126 if (mlen >= 0xffffffff)
127 fatal_f("bad length %zu", mlen);
128 POKE_U32(buf, mlen + 1);
129 buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */
130 if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
131 fatal_f("write: %s", strerror(errno));
132 if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen)
133 fatal_f("write: %s", strerror(errno));
134 }
135
136 void
mm_request_receive(int sock,struct sshbuf * m)137 mm_request_receive(int sock, struct sshbuf *m)
138 {
139 u_char buf[4], *p = NULL;
140 u_int msg_len;
141 int r;
142
143 debug3_f("entering");
144
145 if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
146 if (errno == EPIPE) {
147 debug3_f("monitor fd closed");
148 cleanup_exit(255);
149 }
150 fatal_f("read: %s", strerror(errno));
151 }
152 msg_len = PEEK_U32(buf);
153 if (msg_len > 256 * 1024)
154 fatal_f("read: bad msg_len %d", msg_len);
155 sshbuf_reset(m);
156 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0)
157 fatal_fr(r, "reserve");
158 if (atomicio(read, sock, p, msg_len) != msg_len)
159 fatal_f("read: %s", strerror(errno));
160 }
161
162 void
mm_request_receive_expect(int sock,enum monitor_reqtype type,struct sshbuf * m)163 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m)
164 {
165 u_char rtype;
166 int r;
167
168 debug3_f("entering, type %d", type);
169
170 mm_request_receive(sock, m);
171 if ((r = sshbuf_get_u8(m, &rtype)) != 0)
172 fatal_fr(r, "parse");
173 if (rtype != type)
174 fatal_f("read: rtype %d != type %d", rtype, type);
175 }
176
177 #ifdef WITH_OPENSSL
178 DH *
mm_choose_dh(int min,int nbits,int max)179 mm_choose_dh(int min, int nbits, int max)
180 {
181 BIGNUM *p, *g;
182 int r;
183 u_char success = 0;
184 struct sshbuf *m;
185
186 if ((m = sshbuf_new()) == NULL)
187 fatal_f("sshbuf_new failed");
188 if ((r = sshbuf_put_u32(m, min)) != 0 ||
189 (r = sshbuf_put_u32(m, nbits)) != 0 ||
190 (r = sshbuf_put_u32(m, max)) != 0)
191 fatal_fr(r, "assemble");
192
193 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m);
194
195 debug3_f("waiting for MONITOR_ANS_MODULI");
196 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m);
197
198 if ((r = sshbuf_get_u8(m, &success)) != 0)
199 fatal_fr(r, "parse success");
200 if (success == 0)
201 fatal_f("MONITOR_ANS_MODULI failed");
202
203 if ((r = sshbuf_get_bignum2(m, &p)) != 0 ||
204 (r = sshbuf_get_bignum2(m, &g)) != 0)
205 fatal_fr(r, "parse group");
206
207 debug3_f("remaining %zu", sshbuf_len(m));
208 sshbuf_free(m);
209
210 return (dh_new_group(g, p));
211 }
212 #endif
213
214 int
mm_sshkey_sign(struct ssh * ssh,struct sshkey * key,u_char ** sigp,size_t * lenp,const u_char * data,size_t datalen,const char * hostkey_alg,const char * sk_provider,const char * sk_pin,u_int compat)215 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
216 const u_char *data, size_t datalen, const char *hostkey_alg,
217 const char *sk_provider, const char *sk_pin, u_int compat)
218 {
219 struct kex *kex = *pmonitor->m_pkex;
220 struct sshbuf *m;
221 u_int ndx = kex->host_key_index(key, 0, ssh);
222 int r;
223
224 debug3_f("entering");
225 if ((m = sshbuf_new()) == NULL)
226 fatal_f("sshbuf_new failed");
227 if ((r = sshbuf_put_u32(m, ndx)) != 0 ||
228 (r = sshbuf_put_string(m, data, datalen)) != 0 ||
229 (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 ||
230 (r = sshbuf_put_u32(m, compat)) != 0)
231 fatal_fr(r, "assemble");
232
233 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m);
234
235 debug3_f("waiting for MONITOR_ANS_SIGN");
236 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m);
237 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0)
238 fatal_fr(r, "parse");
239 sshbuf_free(m);
240
241 return (0);
242 }
243
244 void
mm_decode_activate_server_options(struct ssh * ssh,struct sshbuf * m)245 mm_decode_activate_server_options(struct ssh *ssh, struct sshbuf *m)
246 {
247 const u_char *p;
248 size_t len;
249 u_int i;
250 ServerOptions *newopts;
251 int r;
252
253 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0)
254 fatal_fr(r, "parse opts");
255 if (len != sizeof(*newopts))
256 fatal_f("option block size mismatch");
257 newopts = xcalloc(sizeof(*newopts), 1);
258 memcpy(newopts, p, sizeof(*newopts));
259
260 #define M_CP_STROPT(x) do { \
261 if (newopts->x != NULL && \
262 (r = sshbuf_get_cstring(m, &newopts->x, NULL)) != 0) \
263 fatal_fr(r, "parse %s", #x); \
264 } while (0)
265 #define M_CP_STRARRAYOPT(x, nx) do { \
266 newopts->x = newopts->nx == 0 ? \
267 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
268 for (i = 0; i < newopts->nx; i++) { \
269 if ((r = sshbuf_get_cstring(m, \
270 &newopts->x[i], NULL)) != 0) \
271 fatal_fr(r, "parse %s", #x); \
272 } \
273 } while (0)
274 /* See comment in servconf.h */
275 COPY_MATCH_STRING_OPTS();
276 #undef M_CP_STROPT
277 #undef M_CP_STRARRAYOPT
278
279 copy_set_server_options(&options, newopts, 1);
280 log_change_level(options.log_level);
281 log_verbose_reset();
282 for (i = 0; i < options.num_log_verbose; i++)
283 log_verbose_add(options.log_verbose[i]);
284 free(newopts);
285 }
286
287 #define GETPW(b, id) \
288 do { \
289 if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0) \
290 fatal_fr(r, "parse pw %s", #id); \
291 if (len != sizeof(pw->id)) \
292 fatal_fr(r, "bad length for %s", #id); \
293 memcpy(&pw->id, p, len); \
294 } while (0)
295
296 struct passwd *
mm_getpwnamallow(struct ssh * ssh,const char * username)297 mm_getpwnamallow(struct ssh *ssh, const char *username)
298 {
299 struct sshbuf *m;
300 struct passwd *pw;
301 size_t len;
302 int r;
303 u_char ok;
304 const u_char *p;
305
306 debug3_f("entering");
307
308 if ((m = sshbuf_new()) == NULL)
309 fatal_f("sshbuf_new failed");
310 if ((r = sshbuf_put_cstring(m, username)) != 0)
311 fatal_fr(r, "assemble");
312
313 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m);
314
315 debug3_f("waiting for MONITOR_ANS_PWNAM");
316 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m);
317
318 if ((r = sshbuf_get_u8(m, &ok)) != 0)
319 fatal_fr(r, "parse success");
320 if (ok == 0) {
321 pw = NULL;
322 goto out;
323 }
324
325 pw = xcalloc(sizeof(*pw), 1);
326 GETPW(m, pw_uid);
327 GETPW(m, pw_gid);
328 GETPW(m, pw_change);
329 GETPW(m, pw_expire);
330 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 ||
331 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 ||
332 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 ||
333 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 ||
334 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 ||
335 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0)
336 fatal_fr(r, "parse pw");
337
338 out:
339 /* copy options block as a Match directive may have changed some */
340 mm_decode_activate_server_options(ssh, m);
341 server_process_permitopen(ssh);
342 server_process_channel_timeouts(ssh);
343 kex_set_server_sig_algs(ssh, options.pubkey_accepted_algos);
344 sshbuf_free(m);
345
346 return (pw);
347 }
348
349 char *
mm_auth2_read_banner(void)350 mm_auth2_read_banner(void)
351 {
352 struct sshbuf *m;
353 char *banner;
354 int r;
355
356 debug3_f("entering");
357
358 if ((m = sshbuf_new()) == NULL)
359 fatal_f("sshbuf_new failed");
360 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m);
361 sshbuf_reset(m);
362
363 mm_request_receive_expect(pmonitor->m_recvfd,
364 MONITOR_ANS_AUTH2_READ_BANNER, m);
365 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0)
366 fatal_fr(r, "parse");
367 sshbuf_free(m);
368
369 /* treat empty banner as missing banner */
370 if (strlen(banner) == 0) {
371 free(banner);
372 banner = NULL;
373 }
374 return (banner);
375 }
376
377 /* Inform the privileged process about service and style */
378
379 void
mm_inform_authserv(char * service,char * style)380 mm_inform_authserv(char *service, char *style)
381 {
382 struct sshbuf *m;
383 int r;
384
385 debug3_f("entering");
386
387 if ((m = sshbuf_new()) == NULL)
388 fatal_f("sshbuf_new failed");
389 if ((r = sshbuf_put_cstring(m, service)) != 0 ||
390 (r = sshbuf_put_cstring(m, style ? style : "")) != 0)
391 fatal_fr(r, "assemble");
392
393 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m);
394
395 sshbuf_free(m);
396 }
397
398 /* Do the password authentication */
399 int
mm_auth_password(struct ssh * ssh,char * password)400 mm_auth_password(struct ssh *ssh, char *password)
401 {
402 struct sshbuf *m;
403 int r, authenticated = 0;
404
405 debug3_f("entering");
406
407 if ((m = sshbuf_new()) == NULL)
408 fatal_f("sshbuf_new failed");
409 if ((r = sshbuf_put_cstring(m, password)) != 0)
410 fatal_fr(r, "assemble");
411 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m);
412
413 debug3_f("waiting for MONITOR_ANS_AUTHPASSWORD");
414 mm_request_receive_expect(pmonitor->m_recvfd,
415 MONITOR_ANS_AUTHPASSWORD, m);
416
417 if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
418 fatal_fr(r, "parse");
419
420 sshbuf_free(m);
421
422 debug3_f("user %sauthenticated", authenticated ? "" : "not ");
423 return (authenticated);
424 }
425
426 int
mm_user_key_allowed(struct ssh * ssh,struct passwd * pw,struct sshkey * key,int pubkey_auth_attempt,struct sshauthopt ** authoptp)427 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key,
428 int pubkey_auth_attempt, struct sshauthopt **authoptp)
429 {
430 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
431 pubkey_auth_attempt, authoptp));
432 }
433
434 int
mm_hostbased_key_allowed(struct ssh * ssh,struct passwd * pw,const char * user,const char * host,struct sshkey * key)435 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw,
436 const char *user, const char *host, struct sshkey *key)
437 {
438 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL));
439 }
440
441 int
mm_key_allowed(enum mm_keytype type,const char * user,const char * host,struct sshkey * key,int pubkey_auth_attempt,struct sshauthopt ** authoptp)442 mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
443 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp)
444 {
445 struct sshbuf *m;
446 int r, allowed = 0;
447 struct sshauthopt *opts = NULL;
448
449 debug3_f("entering");
450
451 if (authoptp != NULL)
452 *authoptp = NULL;
453
454 if ((m = sshbuf_new()) == NULL)
455 fatal_f("sshbuf_new failed");
456 if ((r = sshbuf_put_u32(m, type)) != 0 ||
457 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 ||
458 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 ||
459 (r = sshkey_puts(key, m)) != 0 ||
460 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0)
461 fatal_fr(r, "assemble");
462
463 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m);
464
465 debug3_f("waiting for MONITOR_ANS_KEYALLOWED");
466 mm_request_receive_expect(pmonitor->m_recvfd,
467 MONITOR_ANS_KEYALLOWED, m);
468
469 if ((r = sshbuf_get_u32(m, &allowed)) != 0)
470 fatal_fr(r, "parse");
471 if (allowed && type == MM_USERKEY &&
472 (r = sshauthopt_deserialise(m, &opts)) != 0)
473 fatal_fr(r, "sshauthopt_deserialise");
474 sshbuf_free(m);
475
476 if (authoptp != NULL) {
477 *authoptp = opts;
478 opts = NULL;
479 }
480 sshauthopt_free(opts);
481
482 return allowed;
483 }
484
485 /*
486 * This key verify needs to send the key type along, because the
487 * privileged parent makes the decision if the key is allowed
488 * for authentication.
489 */
490
491 int
mm_sshkey_verify(const struct sshkey * key,const u_char * sig,size_t siglen,const u_char * data,size_t datalen,const char * sigalg,u_int compat,struct sshkey_sig_details ** sig_detailsp)492 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
493 const u_char *data, size_t datalen, const char *sigalg, u_int compat,
494 struct sshkey_sig_details **sig_detailsp)
495 {
496 struct sshbuf *m;
497 u_int encoded_ret = 0;
498 int r;
499 u_char sig_details_present, flags;
500 u_int counter;
501
502 debug3_f("entering");
503
504 if (sig_detailsp != NULL)
505 *sig_detailsp = NULL;
506 if ((m = sshbuf_new()) == NULL)
507 fatal_f("sshbuf_new failed");
508 if ((r = sshkey_puts(key, m)) != 0 ||
509 (r = sshbuf_put_string(m, sig, siglen)) != 0 ||
510 (r = sshbuf_put_string(m, data, datalen)) != 0 ||
511 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0)
512 fatal_fr(r, "assemble");
513
514 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m);
515
516 debug3_f("waiting for MONITOR_ANS_KEYVERIFY");
517 mm_request_receive_expect(pmonitor->m_recvfd,
518 MONITOR_ANS_KEYVERIFY, m);
519
520 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0 ||
521 (r = sshbuf_get_u8(m, &sig_details_present)) != 0)
522 fatal_fr(r, "parse");
523 if (sig_details_present && encoded_ret == 0) {
524 if ((r = sshbuf_get_u32(m, &counter)) != 0 ||
525 (r = sshbuf_get_u8(m, &flags)) != 0)
526 fatal_fr(r, "parse sig_details");
527 if (sig_detailsp != NULL) {
528 *sig_detailsp = xcalloc(1, sizeof(**sig_detailsp));
529 (*sig_detailsp)->sk_counter = counter;
530 (*sig_detailsp)->sk_flags = flags;
531 }
532 }
533
534 sshbuf_free(m);
535
536 if (encoded_ret != 0)
537 return SSH_ERR_SIGNATURE_INVALID;
538 return 0;
539 }
540
541 void
mm_send_keystate(struct ssh * ssh,struct monitor * monitor)542 mm_send_keystate(struct ssh *ssh, struct monitor *monitor)
543 {
544 struct sshbuf *m;
545 int r;
546
547 if ((m = sshbuf_new()) == NULL)
548 fatal_f("sshbuf_new failed");
549 if ((r = ssh_packet_get_state(ssh, m)) != 0)
550 fatal_fr(r, "ssh_packet_get_state");
551 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
552 debug3_f("Finished sending state");
553 sshbuf_free(m);
554 }
555
556 int
mm_pty_allocate(int * ptyfd,int * ttyfd,char * namebuf,size_t namebuflen)557 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
558 {
559 struct sshbuf *m;
560 char *p, *msg;
561 int success = 0, tmp1 = -1, tmp2 = -1, r;
562
563 /* Kludge: ensure there are fds free to receive the pty/tty */
564 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
565 (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
566 error_f("cannot allocate fds for pty");
567 if (tmp1 >= 0)
568 close(tmp1);
569 return 0;
570 }
571 close(tmp1);
572 close(tmp2);
573
574 if ((m = sshbuf_new()) == NULL)
575 fatal_f("sshbuf_new failed");
576 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m);
577
578 debug3_f("waiting for MONITOR_ANS_PTY");
579 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m);
580
581 if ((r = sshbuf_get_u32(m, &success)) != 0)
582 fatal_fr(r, "parse success");
583 if (success == 0) {
584 debug3_f("pty alloc failed");
585 sshbuf_free(m);
586 return (0);
587 }
588 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 ||
589 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0)
590 fatal_fr(r, "parse");
591 sshbuf_free(m);
592
593 strlcpy(namebuf, p, namebuflen); /* Possible truncation */
594 free(p);
595
596 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0)
597 fatal_fr(r, "put loginmsg");
598 free(msg);
599
600 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
601 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
602 fatal_f("receive fds failed");
603
604 /* Success */
605 return (1);
606 }
607
608 void
mm_session_pty_cleanup2(Session * s)609 mm_session_pty_cleanup2(Session *s)
610 {
611 struct sshbuf *m;
612 int r;
613
614 if (s->ttyfd == -1)
615 return;
616 if ((m = sshbuf_new()) == NULL)
617 fatal_f("sshbuf_new failed");
618 if ((r = sshbuf_put_cstring(m, s->tty)) != 0)
619 fatal_fr(r, "assmble");
620 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m);
621 sshbuf_free(m);
622
623 /* closed dup'ed master */
624 if (s->ptymaster != -1 && close(s->ptymaster) == -1)
625 error("close(s->ptymaster/%d): %s",
626 s->ptymaster, strerror(errno));
627
628 /* unlink pty from session */
629 s->ttyfd = -1;
630 }
631
632 /* Request process termination */
633
634 void
mm_terminate(void)635 mm_terminate(void)
636 {
637 struct sshbuf *m;
638
639 if ((m = sshbuf_new()) == NULL)
640 fatal_f("sshbuf_new failed");
641 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m);
642 sshbuf_free(m);
643 }
644
645 static void
mm_chall_setup(char ** name,char ** infotxt,u_int * numprompts,char *** prompts,u_int ** echo_on)646 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
647 char ***prompts, u_int **echo_on)
648 {
649 *name = xstrdup("");
650 *infotxt = xstrdup("");
651 *numprompts = 1;
652 *prompts = xcalloc(*numprompts, sizeof(char *));
653 *echo_on = xcalloc(*numprompts, sizeof(u_int));
654 (*echo_on)[0] = 0;
655 }
656
657 int
mm_bsdauth_query(void * ctx,char ** name,char ** infotxt,u_int * numprompts,char *** prompts,u_int ** echo_on)658 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
659 u_int *numprompts, char ***prompts, u_int **echo_on)
660 {
661 struct sshbuf *m;
662 u_int success;
663 char *challenge;
664 int r;
665
666 debug3_f("entering");
667
668 if ((m = sshbuf_new()) == NULL)
669 fatal_f("sshbuf_new failed");
670 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m);
671
672 mm_request_receive_expect(pmonitor->m_recvfd,
673 MONITOR_ANS_BSDAUTHQUERY, m);
674 if ((r = sshbuf_get_u32(m, &success)) != 0)
675 fatal_fr(r, "parse success");
676 if (success == 0) {
677 debug3_f("no challenge");
678 sshbuf_free(m);
679 return (-1);
680 }
681
682 /* Get the challenge, and format the response */
683 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0)
684 fatal_fr(r, "parse challenge");
685 sshbuf_free(m);
686
687 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
688 (*prompts)[0] = challenge;
689
690 debug3_f("received challenge: %s", challenge);
691
692 return (0);
693 }
694
695 int
mm_bsdauth_respond(void * ctx,u_int numresponses,char ** responses)696 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
697 {
698 struct sshbuf *m;
699 int r, authok;
700
701 debug3_f("entering");
702 if (numresponses != 1)
703 return (-1);
704
705 if ((m = sshbuf_new()) == NULL)
706 fatal_f("sshbuf_new failed");
707 if ((r = sshbuf_put_cstring(m, responses[0])) != 0)
708 fatal_fr(r, "assemble");
709 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m);
710
711 mm_request_receive_expect(pmonitor->m_recvfd,
712 MONITOR_ANS_BSDAUTHRESPOND, m);
713
714 if ((r = sshbuf_get_u32(m, &authok)) != 0)
715 fatal_fr(r, "parse");
716 sshbuf_free(m);
717
718 return ((authok == 0) ? -1 : 0);
719 }
720
721 #ifdef GSSAPI
722 OM_uint32
mm_ssh_gssapi_server_ctx(Gssctxt ** ctx,gss_OID goid)723 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
724 {
725 struct sshbuf *m;
726 OM_uint32 major;
727 int r;
728
729 /* Client doesn't get to see the context */
730 *ctx = NULL;
731
732 if ((m = sshbuf_new()) == NULL)
733 fatal_f("sshbuf_new failed");
734 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0)
735 fatal_fr(r, "assemble");
736
737 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m);
738 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m);
739
740 if ((r = sshbuf_get_u32(m, &major)) != 0)
741 fatal_fr(r, "parse");
742
743 sshbuf_free(m);
744 return (major);
745 }
746
747 OM_uint32
mm_ssh_gssapi_accept_ctx(Gssctxt * ctx,gss_buffer_desc * in,gss_buffer_desc * out,OM_uint32 * flagsp)748 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
749 gss_buffer_desc *out, OM_uint32 *flagsp)
750 {
751 struct sshbuf *m;
752 OM_uint32 major;
753 u_int flags;
754 int r;
755
756 if ((m = sshbuf_new()) == NULL)
757 fatal_f("sshbuf_new failed");
758 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0)
759 fatal_fr(r, "assemble");
760
761 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m);
762 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m);
763
764 if ((r = sshbuf_get_u32(m, &major)) != 0 ||
765 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0)
766 fatal_fr(r, "parse");
767 if (flagsp != NULL) {
768 if ((r = sshbuf_get_u32(m, &flags)) != 0)
769 fatal_fr(r, "parse flags");
770 *flagsp = flags;
771 }
772
773 sshbuf_free(m);
774
775 return (major);
776 }
777
778 OM_uint32
mm_ssh_gssapi_checkmic(Gssctxt * ctx,gss_buffer_t gssbuf,gss_buffer_t gssmic)779 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
780 {
781 struct sshbuf *m;
782 OM_uint32 major;
783 int r;
784
785 if ((m = sshbuf_new()) == NULL)
786 fatal_f("sshbuf_new failed");
787 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 ||
788 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0)
789 fatal_fr(r, "assemble");
790
791 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m);
792 mm_request_receive_expect(pmonitor->m_recvfd,
793 MONITOR_ANS_GSSCHECKMIC, m);
794
795 if ((r = sshbuf_get_u32(m, &major)) != 0)
796 fatal_fr(r, "parse");
797 sshbuf_free(m);
798 return(major);
799 }
800
801 int
mm_ssh_gssapi_userok(char * user)802 mm_ssh_gssapi_userok(char *user)
803 {
804 struct sshbuf *m;
805 int r, authenticated = 0;
806
807 if ((m = sshbuf_new()) == NULL)
808 fatal_f("sshbuf_new failed");
809
810 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m);
811 mm_request_receive_expect(pmonitor->m_recvfd,
812 MONITOR_ANS_GSSUSEROK, m);
813
814 if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
815 fatal_fr(r, "parse");
816
817 sshbuf_free(m);
818 debug3_f("user %sauthenticated", authenticated ? "" : "not ");
819 return (authenticated);
820 }
821 #endif /* GSSAPI */
822
823 /*
824 * Inform channels layer of permitopen options for a single forwarding
825 * direction (local/remote).
826 */
827 static void
server_process_permitopen_list(struct ssh * ssh,int listen,char ** opens,u_int num_opens)828 server_process_permitopen_list(struct ssh *ssh, int listen,
829 char **opens, u_int num_opens)
830 {
831 u_int i;
832 int port;
833 char *host, *arg, *oarg;
834 int where = listen ? FORWARD_REMOTE : FORWARD_LOCAL;
835 const char *what = listen ? "permitlisten" : "permitopen";
836
837 channel_clear_permission(ssh, FORWARD_ADM, where);
838 if (num_opens == 0)
839 return; /* permit any */
840
841 /* handle keywords: "any" / "none" */
842 if (num_opens == 1 && strcmp(opens[0], "any") == 0)
843 return;
844 if (num_opens == 1 && strcmp(opens[0], "none") == 0) {
845 channel_disable_admin(ssh, where);
846 return;
847 }
848 /* Otherwise treat it as a list of permitted host:port */
849 for (i = 0; i < num_opens; i++) {
850 oarg = arg = xstrdup(opens[i]);
851 host = hpdelim(&arg);
852 if (host == NULL)
853 fatal_f("missing host in %s", what);
854 host = cleanhostname(host);
855 if (arg == NULL || ((port = permitopen_port(arg)) < 0))
856 fatal_f("bad port number in %s", what);
857 /* Send it to channels layer */
858 channel_add_permission(ssh, FORWARD_ADM,
859 where, host, port);
860 free(oarg);
861 }
862 }
863
864 /*
865 * Inform channels layer of permitopen options from configuration.
866 */
867 void
server_process_permitopen(struct ssh * ssh)868 server_process_permitopen(struct ssh *ssh)
869 {
870 server_process_permitopen_list(ssh, 0,
871 options.permitted_opens, options.num_permitted_opens);
872 server_process_permitopen_list(ssh, 1,
873 options.permitted_listens, options.num_permitted_listens);
874 }
875
876 void
server_process_channel_timeouts(struct ssh * ssh)877 server_process_channel_timeouts(struct ssh *ssh)
878 {
879 u_int i, secs;
880 char *type;
881
882 debug3_f("setting %u timeouts", options.num_channel_timeouts);
883 channel_clear_timeouts(ssh);
884 for (i = 0; i < options.num_channel_timeouts; i++) {
885 if (parse_pattern_interval(options.channel_timeouts[i],
886 &type, &secs) != 0) {
887 fatal_f("internal error: bad timeout %s",
888 options.channel_timeouts[i]);
889 }
890 channel_add_timeout(ssh, type, secs);
891 free(type);
892 }
893 }
894
895 struct connection_info *
server_get_connection_info(struct ssh * ssh,int populate,int use_dns)896 server_get_connection_info(struct ssh *ssh, int populate, int use_dns)
897 {
898 static struct connection_info ci;
899
900 if (ssh == NULL || !populate)
901 return &ci;
902 ci.host = use_dns ? ssh_remote_hostname(ssh) : ssh_remote_ipaddr(ssh);
903 ci.address = ssh_remote_ipaddr(ssh);
904 ci.laddress = ssh_local_ipaddr(ssh);
905 ci.lport = ssh_local_port(ssh);
906 ci.rdomain = ssh_packet_rdomain_in(ssh);
907 return &ci;
908 }
909
910