1 /* $OpenBSD: monitor_wrap.c,v 1.129 2023/12/18 14:45:49 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 "includes.h"
29
30 #include <sys/types.h>
31 #include <sys/uio.h>
32
33 #include <errno.h>
34 #include <pwd.h>
35 #include <signal.h>
36 #include <stdarg.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <unistd.h>
40
41 #ifdef WITH_OPENSSL
42 #include <openssl/bn.h>
43 #include <openssl/dh.h>
44 #include <openssl/evp.h>
45 #endif
46
47 #include "openbsd-compat/sys-queue.h"
48 #include "xmalloc.h"
49 #include "ssh.h"
50 #ifdef WITH_OPENSSL
51 #include "dh.h"
52 #endif
53 #include "sshbuf.h"
54 #include "sshkey.h"
55 #include "cipher.h"
56 #include "kex.h"
57 #include "hostfile.h"
58 #include "auth.h"
59 #include "auth-options.h"
60 #include "packet.h"
61 #include "mac.h"
62 #include "log.h"
63 #include "auth-pam.h"
64 #include "monitor.h"
65 #ifdef GSSAPI
66 #include "ssh-gss.h"
67 #endif
68 #include "monitor_wrap.h"
69 #include "atomicio.h"
70 #include "monitor_fdpass.h"
71 #include "misc.h"
72
73 #include "channels.h"
74 #include "session.h"
75 #include "servconf.h"
76
77 #include "ssherr.h"
78
79 /* Imports */
80 extern struct monitor *pmonitor;
81 extern struct sshbuf *loginmsg;
82 extern ServerOptions options;
83
84 void
mm_log_handler(LogLevel level,int forced,const char * msg,void * ctx)85 mm_log_handler(LogLevel level, int forced, const char *msg, void *ctx)
86 {
87 struct sshbuf *log_msg;
88 struct monitor *mon = (struct monitor *)ctx;
89 int r;
90 size_t len;
91
92 if (mon->m_log_sendfd == -1)
93 fatal_f("no log channel");
94
95 if ((log_msg = sshbuf_new()) == NULL)
96 fatal_f("sshbuf_new failed");
97
98 if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */
99 (r = sshbuf_put_u32(log_msg, level)) != 0 ||
100 (r = sshbuf_put_u32(log_msg, forced)) != 0 ||
101 (r = sshbuf_put_cstring(log_msg, msg)) != 0)
102 fatal_fr(r, "assemble");
103 if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff)
104 fatal_f("bad length %zu", len);
105 POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4);
106 if (atomicio(vwrite, mon->m_log_sendfd,
107 sshbuf_mutable_ptr(log_msg), len) != len)
108 fatal_f("write: %s", strerror(errno));
109 sshbuf_free(log_msg);
110 }
111
112 int
mm_is_monitor(void)113 mm_is_monitor(void)
114 {
115 /*
116 * m_pid is only set in the privileged part, and
117 * points to the unprivileged child.
118 */
119 return (pmonitor && pmonitor->m_pid > 0);
120 }
121
122 void
mm_request_send(int sock,enum monitor_reqtype type,struct sshbuf * m)123 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m)
124 {
125 size_t mlen = sshbuf_len(m);
126 u_char buf[5];
127
128 debug3_f("entering, type %d", type);
129
130 if (mlen >= 0xffffffff)
131 fatal_f("bad length %zu", mlen);
132 POKE_U32(buf, mlen + 1);
133 buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */
134 if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
135 fatal_f("write: %s", strerror(errno));
136 if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen)
137 fatal_f("write: %s", strerror(errno));
138 }
139
140 void
mm_request_receive(int sock,struct sshbuf * m)141 mm_request_receive(int sock, struct sshbuf *m)
142 {
143 u_char buf[4], *p = NULL;
144 u_int msg_len;
145 int r;
146
147 debug3_f("entering");
148
149 if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
150 if (errno == EPIPE)
151 cleanup_exit(255);
152 fatal_f("read: %s", strerror(errno));
153 }
154 msg_len = PEEK_U32(buf);
155 if (msg_len > 256 * 1024)
156 fatal_f("read: bad msg_len %d", msg_len);
157 sshbuf_reset(m);
158 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0)
159 fatal_fr(r, "reserve");
160 if (atomicio(read, sock, p, msg_len) != msg_len)
161 fatal_f("read: %s", strerror(errno));
162 }
163
164 void
mm_request_receive_expect(int sock,enum monitor_reqtype type,struct sshbuf * m)165 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m)
166 {
167 u_char rtype;
168 int r;
169
170 debug3_f("entering, type %d", type);
171
172 mm_request_receive(sock, m);
173 if ((r = sshbuf_get_u8(m, &rtype)) != 0)
174 fatal_fr(r, "parse");
175 if (rtype != type)
176 fatal_f("read: rtype %d != type %d", rtype, type);
177 }
178
179 #ifdef WITH_OPENSSL
180 DH *
mm_choose_dh(int min,int nbits,int max)181 mm_choose_dh(int min, int nbits, int max)
182 {
183 BIGNUM *p, *g;
184 int r;
185 u_char success = 0;
186 struct sshbuf *m;
187
188 if ((m = sshbuf_new()) == NULL)
189 fatal_f("sshbuf_new failed");
190 if ((r = sshbuf_put_u32(m, min)) != 0 ||
191 (r = sshbuf_put_u32(m, nbits)) != 0 ||
192 (r = sshbuf_put_u32(m, max)) != 0)
193 fatal_fr(r, "assemble");
194
195 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m);
196
197 debug3_f("waiting for MONITOR_ANS_MODULI");
198 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m);
199
200 if ((r = sshbuf_get_u8(m, &success)) != 0)
201 fatal_fr(r, "parse success");
202 if (success == 0)
203 fatal_f("MONITOR_ANS_MODULI failed");
204
205 if ((r = sshbuf_get_bignum2(m, &p)) != 0 ||
206 (r = sshbuf_get_bignum2(m, &g)) != 0)
207 fatal_fr(r, "parse group");
208
209 debug3_f("remaining %zu", sshbuf_len(m));
210 sshbuf_free(m);
211
212 return (dh_new_group(g, p));
213 }
214 #endif
215
216 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)217 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
218 const u_char *data, size_t datalen, const char *hostkey_alg,
219 const char *sk_provider, const char *sk_pin, u_int compat)
220 {
221 struct kex *kex = *pmonitor->m_pkex;
222 struct sshbuf *m;
223 u_int ndx = kex->host_key_index(key, 0, ssh);
224 int r;
225
226 debug3_f("entering");
227 if ((m = sshbuf_new()) == NULL)
228 fatal_f("sshbuf_new failed");
229 if ((r = sshbuf_put_u32(m, ndx)) != 0 ||
230 (r = sshbuf_put_string(m, data, datalen)) != 0 ||
231 (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 ||
232 (r = sshbuf_put_u32(m, compat)) != 0)
233 fatal_fr(r, "assemble");
234
235 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m);
236
237 debug3_f("waiting for MONITOR_ANS_SIGN");
238 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m);
239 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0)
240 fatal_fr(r, "parse");
241 sshbuf_free(m);
242
243 return (0);
244 }
245
246 #define GETPW(b, id) \
247 do { \
248 if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0) \
249 fatal_fr(r, "parse pw %s", #id); \
250 if (len != sizeof(pw->id)) \
251 fatal_fr(r, "bad length for %s", #id); \
252 memcpy(&pw->id, p, len); \
253 } while (0)
254
255 struct passwd *
mm_getpwnamallow(struct ssh * ssh,const char * username)256 mm_getpwnamallow(struct ssh *ssh, const char *username)
257 {
258 struct sshbuf *m;
259 struct passwd *pw;
260 size_t len;
261 u_int i;
262 ServerOptions *newopts;
263 int r;
264 u_char ok;
265 const u_char *p;
266
267 debug3_f("entering");
268
269 if ((m = sshbuf_new()) == NULL)
270 fatal_f("sshbuf_new failed");
271 if ((r = sshbuf_put_cstring(m, username)) != 0)
272 fatal_fr(r, "assemble");
273
274 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m);
275
276 debug3_f("waiting for MONITOR_ANS_PWNAM");
277 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m);
278
279 if ((r = sshbuf_get_u8(m, &ok)) != 0)
280 fatal_fr(r, "parse success");
281 if (ok == 0) {
282 pw = NULL;
283 goto out;
284 }
285
286 /* XXX don't like passing struct passwd like this */
287 pw = xcalloc(sizeof(*pw), 1);
288 GETPW(m, pw_uid);
289 GETPW(m, pw_gid);
290 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
291 GETPW(m, pw_change);
292 #endif
293 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
294 GETPW(m, pw_expire);
295 #endif
296 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 ||
297 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 ||
298 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
299 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 ||
300 #endif
301 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
302 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 ||
303 #endif
304 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 ||
305 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0)
306 fatal_fr(r, "parse pw");
307
308 out:
309 /* copy options block as a Match directive may have changed some */
310 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0)
311 fatal_fr(r, "parse opts");
312 if (len != sizeof(*newopts))
313 fatal_f("option block size mismatch");
314 newopts = xcalloc(sizeof(*newopts), 1);
315 memcpy(newopts, p, sizeof(*newopts));
316
317 #define M_CP_STROPT(x) do { \
318 if (newopts->x != NULL && \
319 (r = sshbuf_get_cstring(m, &newopts->x, NULL)) != 0) \
320 fatal_fr(r, "parse %s", #x); \
321 } while (0)
322 #define M_CP_STRARRAYOPT(x, nx) do { \
323 newopts->x = newopts->nx == 0 ? \
324 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
325 for (i = 0; i < newopts->nx; i++) { \
326 if ((r = sshbuf_get_cstring(m, \
327 &newopts->x[i], NULL)) != 0) \
328 fatal_fr(r, "parse %s", #x); \
329 } \
330 } while (0)
331 /* See comment in servconf.h */
332 COPY_MATCH_STRING_OPTS();
333 #undef M_CP_STROPT
334 #undef M_CP_STRARRAYOPT
335
336 copy_set_server_options(&options, newopts, 1);
337 log_change_level(options.log_level);
338 log_verbose_reset();
339 for (i = 0; i < options.num_log_verbose; i++)
340 log_verbose_add(options.log_verbose[i]);
341 process_permitopen(ssh, &options);
342 process_channel_timeouts(ssh, &options);
343 kex_set_server_sig_algs(ssh, options.pubkey_accepted_algos);
344 free(newopts);
345 sshbuf_free(m);
346
347 return (pw);
348 }
349
350 char *
mm_auth2_read_banner(void)351 mm_auth2_read_banner(void)
352 {
353 struct sshbuf *m;
354 char *banner;
355 int r;
356
357 debug3_f("entering");
358
359 if ((m = sshbuf_new()) == NULL)
360 fatal_f("sshbuf_new failed");
361 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m);
362 sshbuf_reset(m);
363
364 mm_request_receive_expect(pmonitor->m_recvfd,
365 MONITOR_ANS_AUTH2_READ_BANNER, m);
366 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0)
367 fatal_fr(r, "parse");
368 sshbuf_free(m);
369
370 /* treat empty banner as missing banner */
371 if (strlen(banner) == 0) {
372 free(banner);
373 banner = NULL;
374 }
375 return (banner);
376 }
377
378 /* Inform the privileged process about service and style */
379
380 void
mm_inform_authserv(char * service,char * style)381 mm_inform_authserv(char *service, char *style)
382 {
383 struct sshbuf *m;
384 int r;
385
386 debug3_f("entering");
387
388 if ((m = sshbuf_new()) == NULL)
389 fatal_f("sshbuf_new failed");
390 if ((r = sshbuf_put_cstring(m, service)) != 0 ||
391 (r = sshbuf_put_cstring(m, style ? style : "")) != 0)
392 fatal_fr(r, "assemble");
393
394 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m);
395
396 sshbuf_free(m);
397 }
398
399 /* Do the password authentication */
400 int
mm_auth_password(struct ssh * ssh,char * password)401 mm_auth_password(struct ssh *ssh, char *password)
402 {
403 struct sshbuf *m;
404 int r, authenticated = 0;
405 #ifdef USE_PAM
406 u_int maxtries = 0;
407 #endif
408
409 debug3_f("entering");
410
411 if ((m = sshbuf_new()) == NULL)
412 fatal_f("sshbuf_new failed");
413 if ((r = sshbuf_put_cstring(m, password)) != 0)
414 fatal_fr(r, "assemble");
415 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m);
416
417 debug3_f("waiting for MONITOR_ANS_AUTHPASSWORD");
418 mm_request_receive_expect(pmonitor->m_recvfd,
419 MONITOR_ANS_AUTHPASSWORD, m);
420
421 if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
422 fatal_fr(r, "parse");
423 #ifdef USE_PAM
424 if ((r = sshbuf_get_u32(m, &maxtries)) != 0)
425 fatal_fr(r, "parse PAM");
426 if (maxtries > INT_MAX)
427 fatal_fr(r, "bad maxtries");
428 sshpam_set_maxtries_reached(maxtries);
429 #endif
430
431 sshbuf_free(m);
432
433 debug3_f("user %sauthenticated", authenticated ? "" : "not ");
434 return (authenticated);
435 }
436
437 int
mm_user_key_allowed(struct ssh * ssh,struct passwd * pw,struct sshkey * key,int pubkey_auth_attempt,struct sshauthopt ** authoptp)438 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key,
439 int pubkey_auth_attempt, struct sshauthopt **authoptp)
440 {
441 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
442 pubkey_auth_attempt, authoptp));
443 }
444
445 int
mm_hostbased_key_allowed(struct ssh * ssh,struct passwd * pw,const char * user,const char * host,struct sshkey * key)446 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw,
447 const char *user, const char *host, struct sshkey *key)
448 {
449 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL));
450 }
451
452 int
mm_key_allowed(enum mm_keytype type,const char * user,const char * host,struct sshkey * key,int pubkey_auth_attempt,struct sshauthopt ** authoptp)453 mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
454 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp)
455 {
456 struct sshbuf *m;
457 int r, allowed = 0;
458 struct sshauthopt *opts = NULL;
459
460 debug3_f("entering");
461
462 if (authoptp != NULL)
463 *authoptp = NULL;
464
465 if ((m = sshbuf_new()) == NULL)
466 fatal_f("sshbuf_new failed");
467 if ((r = sshbuf_put_u32(m, type)) != 0 ||
468 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 ||
469 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 ||
470 (r = sshkey_puts(key, m)) != 0 ||
471 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0)
472 fatal_fr(r, "assemble");
473
474 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m);
475
476 debug3_f("waiting for MONITOR_ANS_KEYALLOWED");
477 mm_request_receive_expect(pmonitor->m_recvfd,
478 MONITOR_ANS_KEYALLOWED, m);
479
480 if ((r = sshbuf_get_u32(m, &allowed)) != 0)
481 fatal_fr(r, "parse");
482 if (allowed && type == MM_USERKEY &&
483 (r = sshauthopt_deserialise(m, &opts)) != 0)
484 fatal_fr(r, "sshauthopt_deserialise");
485 sshbuf_free(m);
486
487 if (authoptp != NULL) {
488 *authoptp = opts;
489 opts = NULL;
490 }
491 sshauthopt_free(opts);
492
493 return allowed;
494 }
495
496 /*
497 * This key verify needs to send the key type along, because the
498 * privileged parent makes the decision if the key is allowed
499 * for authentication.
500 */
501
502 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)503 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
504 const u_char *data, size_t datalen, const char *sigalg, u_int compat,
505 struct sshkey_sig_details **sig_detailsp)
506 {
507 struct sshbuf *m;
508 u_int encoded_ret = 0;
509 int r;
510 u_char sig_details_present, flags;
511 u_int counter;
512
513 debug3_f("entering");
514
515 if (sig_detailsp != NULL)
516 *sig_detailsp = NULL;
517 if ((m = sshbuf_new()) == NULL)
518 fatal_f("sshbuf_new failed");
519 if ((r = sshkey_puts(key, m)) != 0 ||
520 (r = sshbuf_put_string(m, sig, siglen)) != 0 ||
521 (r = sshbuf_put_string(m, data, datalen)) != 0 ||
522 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0)
523 fatal_fr(r, "assemble");
524
525 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m);
526
527 debug3_f("waiting for MONITOR_ANS_KEYVERIFY");
528 mm_request_receive_expect(pmonitor->m_recvfd,
529 MONITOR_ANS_KEYVERIFY, m);
530
531 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0 ||
532 (r = sshbuf_get_u8(m, &sig_details_present)) != 0)
533 fatal_fr(r, "parse");
534 if (sig_details_present && encoded_ret == 0) {
535 if ((r = sshbuf_get_u32(m, &counter)) != 0 ||
536 (r = sshbuf_get_u8(m, &flags)) != 0)
537 fatal_fr(r, "parse sig_details");
538 if (sig_detailsp != NULL) {
539 *sig_detailsp = xcalloc(1, sizeof(**sig_detailsp));
540 (*sig_detailsp)->sk_counter = counter;
541 (*sig_detailsp)->sk_flags = flags;
542 }
543 }
544
545 sshbuf_free(m);
546
547 if (encoded_ret != 0)
548 return SSH_ERR_SIGNATURE_INVALID;
549 return 0;
550 }
551
552 void
mm_send_keystate(struct ssh * ssh,struct monitor * monitor)553 mm_send_keystate(struct ssh *ssh, struct monitor *monitor)
554 {
555 struct sshbuf *m;
556 int r;
557
558 if ((m = sshbuf_new()) == NULL)
559 fatal_f("sshbuf_new failed");
560 if ((r = ssh_packet_get_state(ssh, m)) != 0)
561 fatal_fr(r, "ssh_packet_get_state");
562 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
563 debug3_f("Finished sending state");
564 sshbuf_free(m);
565 }
566
567 int
mm_pty_allocate(int * ptyfd,int * ttyfd,char * namebuf,size_t namebuflen)568 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
569 {
570 struct sshbuf *m;
571 char *p, *msg;
572 int success = 0, tmp1 = -1, tmp2 = -1, r;
573
574 /* Kludge: ensure there are fds free to receive the pty/tty */
575 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
576 (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
577 error_f("cannot allocate fds for pty");
578 if (tmp1 >= 0)
579 close(tmp1);
580 return 0;
581 }
582 close(tmp1);
583 close(tmp2);
584
585 if ((m = sshbuf_new()) == NULL)
586 fatal_f("sshbuf_new failed");
587 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m);
588
589 debug3_f("waiting for MONITOR_ANS_PTY");
590 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m);
591
592 if ((r = sshbuf_get_u32(m, &success)) != 0)
593 fatal_fr(r, "parse success");
594 if (success == 0) {
595 debug3_f("pty alloc failed");
596 sshbuf_free(m);
597 return (0);
598 }
599 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 ||
600 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0)
601 fatal_fr(r, "parse");
602 sshbuf_free(m);
603
604 strlcpy(namebuf, p, namebuflen); /* Possible truncation */
605 free(p);
606
607 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0)
608 fatal_fr(r, "put loginmsg");
609 free(msg);
610
611 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
612 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
613 fatal_f("receive fds failed");
614
615 /* Success */
616 return (1);
617 }
618
619 void
mm_session_pty_cleanup2(Session * s)620 mm_session_pty_cleanup2(Session *s)
621 {
622 struct sshbuf *m;
623 int r;
624
625 if (s->ttyfd == -1)
626 return;
627 if ((m = sshbuf_new()) == NULL)
628 fatal_f("sshbuf_new failed");
629 if ((r = sshbuf_put_cstring(m, s->tty)) != 0)
630 fatal_fr(r, "assmble");
631 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m);
632 sshbuf_free(m);
633
634 /* closed dup'ed master */
635 if (s->ptymaster != -1 && close(s->ptymaster) == -1)
636 error("close(s->ptymaster/%d): %s",
637 s->ptymaster, strerror(errno));
638
639 /* unlink pty from session */
640 s->ttyfd = -1;
641 }
642
643 #ifdef USE_PAM
644 void
mm_start_pam(struct ssh * ssh)645 mm_start_pam(struct ssh *ssh)
646 {
647 struct sshbuf *m;
648
649 debug3("%s entering", __func__);
650 if (!options.use_pam)
651 fatal("UsePAM=no, but ended up in %s anyway", __func__);
652 if ((m = sshbuf_new()) == NULL)
653 fatal("%s: sshbuf_new failed", __func__);
654 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m);
655
656 sshbuf_free(m);
657 }
658
659 u_int
mm_do_pam_account(void)660 mm_do_pam_account(void)
661 {
662 struct sshbuf *m;
663 u_int ret;
664 char *msg;
665 size_t msglen;
666 int r;
667
668 debug3("%s entering", __func__);
669 if (!options.use_pam)
670 fatal("UsePAM=no, but ended up in %s anyway", __func__);
671
672 if ((m = sshbuf_new()) == NULL)
673 fatal("%s: sshbuf_new failed", __func__);
674 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m);
675
676 mm_request_receive_expect(pmonitor->m_recvfd,
677 MONITOR_ANS_PAM_ACCOUNT, m);
678 if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
679 (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 ||
680 (r = sshbuf_put(loginmsg, msg, msglen)) != 0)
681 fatal("%s: buffer error: %s", __func__, ssh_err(r));
682
683 free(msg);
684 sshbuf_free(m);
685
686 debug3("%s returning %d", __func__, ret);
687
688 return (ret);
689 }
690
691 void *
mm_sshpam_init_ctx(Authctxt * authctxt)692 mm_sshpam_init_ctx(Authctxt *authctxt)
693 {
694 struct sshbuf *m;
695 int r, success;
696
697 debug3("%s", __func__);
698 if ((m = sshbuf_new()) == NULL)
699 fatal("%s: sshbuf_new failed", __func__);
700 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m);
701 debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
702 mm_request_receive_expect(pmonitor->m_recvfd,
703 MONITOR_ANS_PAM_INIT_CTX, m);
704 if ((r = sshbuf_get_u32(m, &success)) != 0)
705 fatal("%s: buffer error: %s", __func__, ssh_err(r));
706 if (success == 0) {
707 debug3("%s: pam_init_ctx failed", __func__);
708 sshbuf_free(m);
709 return (NULL);
710 }
711 sshbuf_free(m);
712 return (authctxt);
713 }
714
715 int
mm_sshpam_query(void * ctx,char ** name,char ** info,u_int * num,char *** prompts,u_int ** echo_on)716 mm_sshpam_query(void *ctx, char **name, char **info,
717 u_int *num, char ***prompts, u_int **echo_on)
718 {
719 struct sshbuf *m;
720 u_int i, n;
721 int r, ret;
722
723 debug3("%s", __func__);
724 if ((m = sshbuf_new()) == NULL)
725 fatal("%s: sshbuf_new failed", __func__);
726 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m);
727 debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__);
728 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m);
729 if ((r = sshbuf_get_u32(m, &ret)) != 0 ||
730 (r = sshbuf_get_cstring(m, name, NULL)) != 0 ||
731 (r = sshbuf_get_cstring(m, info, NULL)) != 0 ||
732 (r = sshbuf_get_u32(m, &n)) != 0 ||
733 (r = sshbuf_get_u32(m, num)) != 0)
734 fatal("%s: buffer error: %s", __func__, ssh_err(r));
735 debug3("%s: pam_query returned %d", __func__, ret);
736 sshpam_set_maxtries_reached(n);
737 if (*num > PAM_MAX_NUM_MSG)
738 fatal("%s: received %u PAM messages, expected <= %u",
739 __func__, *num, PAM_MAX_NUM_MSG);
740 *prompts = xcalloc((*num + 1), sizeof(char *));
741 *echo_on = xcalloc((*num + 1), sizeof(u_int));
742 for (i = 0; i < *num; ++i) {
743 if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 ||
744 (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0)
745 fatal("%s: buffer error: %s", __func__, ssh_err(r));
746 }
747 sshbuf_free(m);
748 return (ret);
749 }
750
751 int
mm_sshpam_respond(void * ctx,u_int num,char ** resp)752 mm_sshpam_respond(void *ctx, u_int num, char **resp)
753 {
754 struct sshbuf *m;
755 u_int n, i;
756 int r, ret;
757
758 debug3("%s", __func__);
759 if ((m = sshbuf_new()) == NULL)
760 fatal("%s: sshbuf_new failed", __func__);
761 if ((r = sshbuf_put_u32(m, num)) != 0)
762 fatal("%s: buffer error: %s", __func__, ssh_err(r));
763 for (i = 0; i < num; ++i) {
764 if ((r = sshbuf_put_cstring(m, resp[i])) != 0)
765 fatal("%s: buffer error: %s", __func__, ssh_err(r));
766 }
767 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m);
768 debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
769 mm_request_receive_expect(pmonitor->m_recvfd,
770 MONITOR_ANS_PAM_RESPOND, m);
771 if ((r = sshbuf_get_u32(m, &n)) != 0)
772 fatal("%s: buffer error: %s", __func__, ssh_err(r));
773 ret = (int)n; /* XXX */
774 debug3("%s: pam_respond returned %d", __func__, ret);
775 sshbuf_free(m);
776 return (ret);
777 }
778
779 void
mm_sshpam_free_ctx(void * ctxtp)780 mm_sshpam_free_ctx(void *ctxtp)
781 {
782 struct sshbuf *m;
783
784 debug3("%s", __func__);
785 if ((m = sshbuf_new()) == NULL)
786 fatal("%s: sshbuf_new failed", __func__);
787 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m);
788 debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__);
789 mm_request_receive_expect(pmonitor->m_recvfd,
790 MONITOR_ANS_PAM_FREE_CTX, m);
791 sshbuf_free(m);
792 }
793 #endif /* USE_PAM */
794
795 /* Request process termination */
796
797 void
mm_terminate(void)798 mm_terminate(void)
799 {
800 struct sshbuf *m;
801
802 if ((m = sshbuf_new()) == NULL)
803 fatal_f("sshbuf_new failed");
804 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m);
805 sshbuf_free(m);
806 }
807
808 static void
mm_chall_setup(char ** name,char ** infotxt,u_int * numprompts,char *** prompts,u_int ** echo_on)809 mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
810 char ***prompts, u_int **echo_on)
811 {
812 *name = xstrdup("");
813 *infotxt = xstrdup("");
814 *numprompts = 1;
815 *prompts = xcalloc(*numprompts, sizeof(char *));
816 *echo_on = xcalloc(*numprompts, sizeof(u_int));
817 (*echo_on)[0] = 0;
818 }
819
820 int
mm_bsdauth_query(void * ctx,char ** name,char ** infotxt,u_int * numprompts,char *** prompts,u_int ** echo_on)821 mm_bsdauth_query(void *ctx, char **name, char **infotxt,
822 u_int *numprompts, char ***prompts, u_int **echo_on)
823 {
824 struct sshbuf *m;
825 u_int success;
826 char *challenge;
827 int r;
828
829 debug3_f("entering");
830
831 if ((m = sshbuf_new()) == NULL)
832 fatal_f("sshbuf_new failed");
833 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m);
834
835 mm_request_receive_expect(pmonitor->m_recvfd,
836 MONITOR_ANS_BSDAUTHQUERY, m);
837 if ((r = sshbuf_get_u32(m, &success)) != 0)
838 fatal_fr(r, "parse success");
839 if (success == 0) {
840 debug3_f("no challenge");
841 sshbuf_free(m);
842 return (-1);
843 }
844
845 /* Get the challenge, and format the response */
846 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0)
847 fatal_fr(r, "parse challenge");
848 sshbuf_free(m);
849
850 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
851 (*prompts)[0] = challenge;
852
853 debug3_f("received challenge: %s", challenge);
854
855 return (0);
856 }
857
858 int
mm_bsdauth_respond(void * ctx,u_int numresponses,char ** responses)859 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
860 {
861 struct sshbuf *m;
862 int r, authok;
863
864 debug3_f("entering");
865 if (numresponses != 1)
866 return (-1);
867
868 if ((m = sshbuf_new()) == NULL)
869 fatal_f("sshbuf_new failed");
870 if ((r = sshbuf_put_cstring(m, responses[0])) != 0)
871 fatal_fr(r, "assemble");
872 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m);
873
874 mm_request_receive_expect(pmonitor->m_recvfd,
875 MONITOR_ANS_BSDAUTHRESPOND, m);
876
877 if ((r = sshbuf_get_u32(m, &authok)) != 0)
878 fatal_fr(r, "parse");
879 sshbuf_free(m);
880
881 return ((authok == 0) ? -1 : 0);
882 }
883
884 #ifdef SSH_AUDIT_EVENTS
885 void
mm_audit_event(struct ssh * ssh,ssh_audit_event_t event)886 mm_audit_event(struct ssh *ssh, ssh_audit_event_t event)
887 {
888 struct sshbuf *m;
889 int r;
890
891 debug3("%s entering", __func__);
892
893 if ((m = sshbuf_new()) == NULL)
894 fatal("%s: sshbuf_new failed", __func__);
895 if ((r = sshbuf_put_u32(m, event)) != 0)
896 fatal("%s: buffer error: %s", __func__, ssh_err(r));
897
898 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m);
899 sshbuf_free(m);
900 }
901
902 void
mm_audit_run_command(const char * command)903 mm_audit_run_command(const char *command)
904 {
905 struct sshbuf *m;
906 int r;
907
908 debug3("%s entering command %s", __func__, command);
909
910 if ((m = sshbuf_new()) == NULL)
911 fatal("%s: sshbuf_new failed", __func__);
912 if ((r = sshbuf_put_cstring(m, command)) != 0)
913 fatal("%s: buffer error: %s", __func__, ssh_err(r));
914
915 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m);
916 sshbuf_free(m);
917 }
918 #endif /* SSH_AUDIT_EVENTS */
919
920 #ifdef GSSAPI
921 OM_uint32
mm_ssh_gssapi_server_ctx(Gssctxt ** ctx,gss_OID goid)922 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
923 {
924 struct sshbuf *m;
925 OM_uint32 major;
926 int r;
927
928 /* Client doesn't get to see the context */
929 *ctx = NULL;
930
931 if ((m = sshbuf_new()) == NULL)
932 fatal_f("sshbuf_new failed");
933 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0)
934 fatal_fr(r, "assemble");
935
936 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m);
937 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m);
938
939 if ((r = sshbuf_get_u32(m, &major)) != 0)
940 fatal_fr(r, "parse");
941
942 sshbuf_free(m);
943 return (major);
944 }
945
946 OM_uint32
mm_ssh_gssapi_accept_ctx(Gssctxt * ctx,gss_buffer_desc * in,gss_buffer_desc * out,OM_uint32 * flagsp)947 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
948 gss_buffer_desc *out, OM_uint32 *flagsp)
949 {
950 struct sshbuf *m;
951 OM_uint32 major;
952 u_int flags;
953 int r;
954
955 if ((m = sshbuf_new()) == NULL)
956 fatal_f("sshbuf_new failed");
957 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0)
958 fatal_fr(r, "assemble");
959
960 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m);
961 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m);
962
963 if ((r = sshbuf_get_u32(m, &major)) != 0 ||
964 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0)
965 fatal_fr(r, "parse");
966 if (flagsp != NULL) {
967 if ((r = sshbuf_get_u32(m, &flags)) != 0)
968 fatal_fr(r, "parse flags");
969 *flagsp = flags;
970 }
971
972 sshbuf_free(m);
973
974 return (major);
975 }
976
977 OM_uint32
mm_ssh_gssapi_checkmic(Gssctxt * ctx,gss_buffer_t gssbuf,gss_buffer_t gssmic)978 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
979 {
980 struct sshbuf *m;
981 OM_uint32 major;
982 int r;
983
984 if ((m = sshbuf_new()) == NULL)
985 fatal_f("sshbuf_new failed");
986 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 ||
987 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0)
988 fatal_fr(r, "assemble");
989
990 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m);
991 mm_request_receive_expect(pmonitor->m_recvfd,
992 MONITOR_ANS_GSSCHECKMIC, m);
993
994 if ((r = sshbuf_get_u32(m, &major)) != 0)
995 fatal_fr(r, "parse");
996 sshbuf_free(m);
997 return(major);
998 }
999
1000 int
mm_ssh_gssapi_userok(char * user)1001 mm_ssh_gssapi_userok(char *user)
1002 {
1003 struct sshbuf *m;
1004 int r, authenticated = 0;
1005
1006 if ((m = sshbuf_new()) == NULL)
1007 fatal_f("sshbuf_new failed");
1008
1009 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m);
1010 mm_request_receive_expect(pmonitor->m_recvfd,
1011 MONITOR_ANS_GSSUSEROK, m);
1012
1013 if ((r = sshbuf_get_u32(m, &authenticated)) != 0)
1014 fatal_fr(r, "parse");
1015
1016 sshbuf_free(m);
1017 debug3_f("user %sauthenticated", authenticated ? "" : "not ");
1018 return (authenticated);
1019 }
1020 #endif /* GSSAPI */
1021