1 /* $OpenBSD: monitor.c,v 1.235 2023/02/17 04:22:50 dtucker Exp $ */
3 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
4 * Copyright 2002 Markus Friedl <markus@openbsd.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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.
30 #include <sys/types.h>
31 #include <sys/socket.h>
53 # ifdef HAVE_SYS_POLL_H
54 # include <sys/poll.h>
59 #include <openssl/dh.h>
62 #include "openbsd-compat/sys-tree.h"
63 #include "openbsd-compat/sys-queue.h"
64 #include "openbsd-compat/openssl-compat.h"
78 #include "auth-options.h"
91 #include "monitor_wrap.h"
92 #include "monitor_fdpass.h"
101 static Gssctxt *gsscontext = NULL;
105 extern ServerOptions options;
106 extern u_int utmp_len;
107 extern struct sshbuf *loginmsg;
108 extern struct sshauthopt *auth_opts; /* XXX move to permanent ssh->authctxt? */
110 /* State exported from the child */
111 static struct sshbuf *child_state;
113 /* Functions on the monitor that answer unprivileged requests */
115 int mm_answer_moduli(struct ssh *, int, struct sshbuf *);
116 int mm_answer_sign(struct ssh *, int, struct sshbuf *);
117 int mm_answer_pwnamallow(struct ssh *, int, struct sshbuf *);
118 int mm_answer_auth2_read_banner(struct ssh *, int, struct sshbuf *);
119 int mm_answer_authserv(struct ssh *, int, struct sshbuf *);
120 int mm_answer_authpassword(struct ssh *, int, struct sshbuf *);
121 int mm_answer_bsdauthquery(struct ssh *, int, struct sshbuf *);
122 int mm_answer_bsdauthrespond(struct ssh *, int, struct sshbuf *);
123 int mm_answer_keyallowed(struct ssh *, int, struct sshbuf *);
124 int mm_answer_keyverify(struct ssh *, int, struct sshbuf *);
125 int mm_answer_pty(struct ssh *, int, struct sshbuf *);
126 int mm_answer_pty_cleanup(struct ssh *, int, struct sshbuf *);
127 int mm_answer_term(struct ssh *, int, struct sshbuf *);
128 int mm_answer_rsa_keyallowed(struct ssh *, int, struct sshbuf *);
129 int mm_answer_rsa_challenge(struct ssh *, int, struct sshbuf *);
130 int mm_answer_rsa_response(struct ssh *, int, struct sshbuf *);
131 int mm_answer_sesskey(struct ssh *, int, struct sshbuf *);
132 int mm_answer_sessid(struct ssh *, int, struct sshbuf *);
135 int mm_answer_pam_start(struct ssh *, int, struct sshbuf *);
136 int mm_answer_pam_account(struct ssh *, int, struct sshbuf *);
137 int mm_answer_pam_init_ctx(struct ssh *, int, struct sshbuf *);
138 int mm_answer_pam_query(struct ssh *, int, struct sshbuf *);
139 int mm_answer_pam_respond(struct ssh *, int, struct sshbuf *);
140 int mm_answer_pam_free_ctx(struct ssh *, int, struct sshbuf *);
144 int mm_answer_gss_setup_ctx(struct ssh *, int, struct sshbuf *);
145 int mm_answer_gss_accept_ctx(struct ssh *, int, struct sshbuf *);
146 int mm_answer_gss_userok(struct ssh *, int, struct sshbuf *);
147 int mm_answer_gss_checkmic(struct ssh *, int, struct sshbuf *);
150 #ifdef SSH_AUDIT_EVENTS
151 int mm_answer_audit_event(struct ssh *, int, struct sshbuf *);
152 int mm_answer_audit_command(struct ssh *, int, struct sshbuf *);
155 static Authctxt *authctxt;
157 /* local state for key verify */
158 static u_char *key_blob = NULL;
159 static size_t key_bloblen = 0;
160 static u_int key_blobtype = MM_NOKEY;
161 static struct sshauthopt *key_opts = NULL;
162 static char *hostbased_cuser = NULL;
163 static char *hostbased_chost = NULL;
164 static char *auth_method = "unknown";
165 static char *auth_submethod = NULL;
166 static u_int session_id2_len = 0;
167 static u_char *session_id2 = NULL;
168 static pid_t monitor_child_pid;
171 enum monitor_reqtype type;
173 int (*f)(struct ssh *, int, struct sshbuf *);
176 #define MON_ISAUTH 0x0004 /* Required for Authentication */
177 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
178 #define MON_ONCE 0x0010 /* Disable after calling */
179 #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
181 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
183 #define MON_PERMIT 0x1000 /* Request is permitted */
185 static int monitor_read(struct ssh *, struct monitor *, struct mon_table *,
186 struct mon_table **);
187 static int monitor_read_log(struct monitor *);
189 struct mon_table mon_dispatch_proto20[] = {
191 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
193 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
194 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
195 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
196 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
197 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
199 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
200 {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
201 {MONITOR_REQ_PAM_INIT_CTX, MON_ONCE, mm_answer_pam_init_ctx},
202 {MONITOR_REQ_PAM_QUERY, 0, mm_answer_pam_query},
203 {MONITOR_REQ_PAM_RESPOND, MON_ONCE, mm_answer_pam_respond},
204 {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
206 #ifdef SSH_AUDIT_EVENTS
207 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
210 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
211 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
213 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
214 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
216 {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
217 {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
218 {MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok},
219 {MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic},
224 struct mon_table mon_dispatch_postauth20[] = {
226 {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
228 {MONITOR_REQ_SIGN, 0, mm_answer_sign},
229 {MONITOR_REQ_PTY, 0, mm_answer_pty},
230 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
231 {MONITOR_REQ_TERM, 0, mm_answer_term},
232 #ifdef SSH_AUDIT_EVENTS
233 {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
234 {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
239 struct mon_table *mon_dispatch;
241 /* Specifies if a certain message is allowed at the moment */
243 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
245 while (ent->f != NULL) {
246 if (ent->type == type) {
247 ent->flags &= ~MON_PERMIT;
248 ent->flags |= permit ? MON_PERMIT : 0;
256 monitor_permit_authentications(int permit)
258 struct mon_table *ent = mon_dispatch;
260 while (ent->f != NULL) {
261 if (ent->flags & MON_AUTH) {
262 ent->flags &= ~MON_PERMIT;
263 ent->flags |= permit ? MON_PERMIT : 0;
270 monitor_child_preauth(struct ssh *ssh, struct monitor *pmonitor)
272 struct mon_table *ent;
273 int authenticated = 0, partial = 0;
275 debug3("preauth child monitor started");
277 if (pmonitor->m_recvfd >= 0)
278 close(pmonitor->m_recvfd);
279 if (pmonitor->m_log_sendfd >= 0)
280 close(pmonitor->m_log_sendfd);
281 pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
283 authctxt = (Authctxt *)ssh->authctxt;
284 memset(authctxt, 0, sizeof(*authctxt));
285 ssh->authctxt = authctxt;
287 authctxt->loginmsg = loginmsg;
289 mon_dispatch = mon_dispatch_proto20;
290 /* Permit requests for moduli and signatures */
291 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
292 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
294 /* The first few requests do not require asynchronous access */
295 while (!authenticated) {
297 auth_method = "unknown";
298 auth_submethod = NULL;
299 auth2_authctxt_reset_info(authctxt);
301 authenticated = (monitor_read(ssh, pmonitor,
302 mon_dispatch, &ent) == 1);
304 /* Special handling for multiple required authentications */
305 if (options.num_auth_methods != 0) {
307 !auth2_update_methods_lists(authctxt,
308 auth_method, auth_submethod)) {
309 debug3_f("method %s: partial", auth_method);
316 if (!(ent->flags & MON_AUTHDECIDE))
317 fatal_f("unexpected authentication from %d",
319 if (authctxt->pw->pw_uid == 0 &&
320 !auth_root_allowed(ssh, auth_method))
323 /* PAM needs to perform account checks after auth */
324 if (options.use_pam && authenticated) {
327 if ((m = sshbuf_new()) == NULL)
328 fatal("%s: sshbuf_new failed",
330 mm_request_receive_expect(pmonitor->m_sendfd,
331 MONITOR_REQ_PAM_ACCOUNT, m);
332 authenticated = mm_answer_pam_account(
333 ssh, pmonitor->m_sendfd, m);
338 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
339 auth_log(ssh, authenticated, partial,
340 auth_method, auth_submethod);
341 if (!partial && !authenticated)
342 authctxt->failures++;
343 if (authenticated || partial) {
344 auth2_update_session_info(authctxt,
345 auth_method, auth_submethod);
350 if (!authctxt->valid)
351 fatal_f("authenticated invalid user");
352 if (strcmp(auth_method, "unknown") == 0)
353 fatal_f("authentication method name unknown");
355 debug_f("user %s authenticated by privileged process", authctxt->user);
356 ssh->authctxt = NULL;
357 ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user);
359 mm_get_keystate(ssh, pmonitor);
361 /* Drain any buffered messages from the child */
362 while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
365 if (pmonitor->m_recvfd >= 0)
366 close(pmonitor->m_recvfd);
367 if (pmonitor->m_log_sendfd >= 0)
368 close(pmonitor->m_log_sendfd);
369 pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
373 monitor_set_child_handler(pid_t pid)
375 monitor_child_pid = pid;
379 monitor_child_handler(int sig)
381 kill(monitor_child_pid, sig);
385 monitor_child_postauth(struct ssh *ssh, struct monitor *pmonitor)
387 close(pmonitor->m_recvfd);
388 pmonitor->m_recvfd = -1;
390 monitor_set_child_handler(pmonitor->m_pid);
391 ssh_signal(SIGHUP, &monitor_child_handler);
392 ssh_signal(SIGTERM, &monitor_child_handler);
393 ssh_signal(SIGINT, &monitor_child_handler);
395 ssh_signal(SIGXFSZ, SIG_IGN);
398 mon_dispatch = mon_dispatch_postauth20;
400 /* Permit requests for moduli and signatures */
401 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
402 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
403 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
405 if (auth_opts->permit_pty_flag) {
406 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
407 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
411 monitor_read(ssh, pmonitor, mon_dispatch, NULL);
415 monitor_read_log(struct monitor *pmonitor)
417 struct sshbuf *logmsg;
418 u_int len, level, forced;
423 if ((logmsg = sshbuf_new()) == NULL)
424 fatal_f("sshbuf_new");
427 if ((r = sshbuf_reserve(logmsg, 4, &p)) != 0)
428 fatal_fr(r, "reserve len");
429 if (atomicio(read, pmonitor->m_log_recvfd, p, 4) != 4) {
430 if (errno == EPIPE) {
432 debug_f("child log fd closed");
433 close(pmonitor->m_log_recvfd);
434 pmonitor->m_log_recvfd = -1;
437 fatal_f("log fd read: %s", strerror(errno));
439 if ((r = sshbuf_get_u32(logmsg, &len)) != 0)
440 fatal_fr(r, "parse len");
441 if (len <= 4 || len > 8192)
442 fatal_f("invalid log message length %u", len);
444 /* Read severity, message */
445 sshbuf_reset(logmsg);
446 if ((r = sshbuf_reserve(logmsg, len, &p)) != 0)
447 fatal_fr(r, "reserve msg");
448 if (atomicio(read, pmonitor->m_log_recvfd, p, len) != len)
449 fatal_f("log fd read: %s", strerror(errno));
450 if ((r = sshbuf_get_u32(logmsg, &level)) != 0 ||
451 (r = sshbuf_get_u32(logmsg, &forced)) != 0 ||
452 (r = sshbuf_get_cstring(logmsg, &msg, NULL)) != 0)
453 fatal_fr(r, "parse");
456 if (log_level_name(level) == NULL)
457 fatal_f("invalid log level %u (corrupted message?)", level);
458 sshlogdirect(level, forced, "%s [preauth]", msg);
467 monitor_read(struct ssh *ssh, struct monitor *pmonitor, struct mon_table *ent,
468 struct mon_table **pent)
473 struct pollfd pfd[2];
476 memset(&pfd, 0, sizeof(pfd));
477 pfd[0].fd = pmonitor->m_sendfd;
478 pfd[0].events = POLLIN;
479 pfd[1].fd = pmonitor->m_log_recvfd;
480 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
481 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
482 if (errno == EINTR || errno == EAGAIN)
484 fatal_f("poll: %s", strerror(errno));
486 if (pfd[1].revents) {
488 * Drain all log messages before processing next
491 monitor_read_log(pmonitor);
495 break; /* Continues below */
498 if ((m = sshbuf_new()) == NULL)
499 fatal_f("sshbuf_new");
501 mm_request_receive(pmonitor->m_sendfd, m);
502 if ((r = sshbuf_get_u8(m, &type)) != 0)
503 fatal_fr(r, "parse type");
505 debug3_f("checking request %d", type);
507 while (ent->f != NULL) {
508 if (ent->type == type)
513 if (ent->f != NULL) {
514 if (!(ent->flags & MON_PERMIT))
515 fatal_f("unpermitted request %d", type);
516 ret = (*ent->f)(ssh, pmonitor->m_sendfd, m);
519 /* The child may use this request only once, disable it */
520 if (ent->flags & MON_ONCE) {
521 debug2_f("%d used once, disabling now", type);
522 ent->flags &= ~MON_PERMIT;
531 fatal_f("unsupported request: %d", type);
537 /* allowed key state */
539 monitor_allowed_key(const u_char *blob, u_int bloblen)
541 /* make sure key is allowed */
542 if (key_blob == NULL || key_bloblen != bloblen ||
543 timingsafe_bcmp(key_blob, blob, key_bloblen))
549 monitor_reset_key_state(void)
553 free(hostbased_cuser);
554 free(hostbased_chost);
555 sshauthopt_free(key_opts);
558 key_blobtype = MM_NOKEY;
560 hostbased_cuser = NULL;
561 hostbased_chost = NULL;
566 mm_answer_moduli(struct ssh *ssh, int sock, struct sshbuf *m)
569 const BIGNUM *dh_p, *dh_g;
571 u_int min, want, max;
573 if ((r = sshbuf_get_u32(m, &min)) != 0 ||
574 (r = sshbuf_get_u32(m, &want)) != 0 ||
575 (r = sshbuf_get_u32(m, &max)) != 0)
576 fatal_fr(r, "parse");
578 debug3_f("got parameters: %d %d %d", min, want, max);
579 /* We need to check here, too, in case the child got corrupted */
580 if (max < min || want < min || max < want)
581 fatal_f("bad parameters: %d %d %d", min, want, max);
585 dh = choose_dh(min, want, max);
587 if ((r = sshbuf_put_u8(m, 0)) != 0)
588 fatal_fr(r, "assemble empty");
591 /* Send first bignum */
592 DH_get0_pqg(dh, &dh_p, NULL, &dh_g);
593 if ((r = sshbuf_put_u8(m, 1)) != 0 ||
594 (r = sshbuf_put_bignum2(m, dh_p)) != 0 ||
595 (r = sshbuf_put_bignum2(m, dh_g)) != 0)
596 fatal_fr(r, "assemble");
600 mm_request_send(sock, MONITOR_ANS_MODULI, m);
606 mm_answer_sign(struct ssh *ssh, int sock, struct sshbuf *m)
608 extern int auth_sock; /* XXX move to state struct? */
610 struct sshbuf *sigbuf = NULL;
611 u_char *p = NULL, *signature = NULL;
613 size_t datlen, siglen, alglen;
616 const char proof_req[] = "hostkeys-prove-00@openssh.com";
618 debug3_f("entering");
620 if ((r = sshbuf_get_u32(m, &keyid)) != 0 ||
621 (r = sshbuf_get_string(m, &p, &datlen)) != 0 ||
622 (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0 ||
623 (r = sshbuf_get_u32(m, &compat)) != 0)
624 fatal_fr(r, "parse");
626 fatal_f("invalid key ID");
629 * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
630 * SHA384 (48 bytes) and SHA512 (64 bytes).
632 * Otherwise, verify the signature request is for a hostkey
635 * XXX perform similar check for KEX signature requests too?
636 * it's not trivial, since what is signed is the hash, rather
637 * than the full kex structure...
639 if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) {
641 * Construct expected hostkey proof and compare it to what
642 * the client sent us.
644 if (session_id2_len == 0) /* hostkeys is never first */
645 fatal_f("bad data length: %zu", datlen);
646 if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL)
647 fatal_f("no hostkey for index %d", keyid);
648 if ((sigbuf = sshbuf_new()) == NULL)
649 fatal_f("sshbuf_new");
650 if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 ||
651 (r = sshbuf_put_string(sigbuf, session_id2,
652 session_id2_len)) != 0 ||
653 (r = sshkey_puts(key, sigbuf)) != 0)
654 fatal_fr(r, "assemble private key proof");
655 if (datlen != sshbuf_len(sigbuf) ||
656 memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0)
657 fatal_f("bad data length: %zu, hostkey proof len %zu",
658 datlen, sshbuf_len(sigbuf));
663 /* save session id, it will be passed on the first call */
664 if (session_id2_len == 0) {
665 session_id2_len = datlen;
666 session_id2 = xmalloc(session_id2_len);
667 memcpy(session_id2, p, session_id2_len);
670 if ((key = get_hostkey_by_index(keyid)) != NULL) {
671 if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg,
672 options.sk_provider, NULL, compat)) != 0)
674 } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL &&
676 if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen,
677 p, datlen, alg, compat)) != 0)
678 fatal_fr(r, "agent sign");
680 fatal_f("no hostkey from index %d", keyid);
682 debug3_f("%s %s signature len=%zu", alg,
683 is_proof ? "hostkey proof" : "KEX", siglen);
686 if ((r = sshbuf_put_string(m, signature, siglen)) != 0)
687 fatal_fr(r, "assemble");
693 mm_request_send(sock, MONITOR_ANS_SIGN, m);
695 /* Turn on permissions for getpwnam */
696 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
701 #define PUTPW(b, id) \
703 if ((r = sshbuf_put_string(b, \
704 &pwent->id, sizeof(pwent->id))) != 0) \
705 fatal_fr(r, "assemble %s", #id); \
708 /* Retrieves the password entry and also checks if the user is permitted */
710 mm_answer_pwnamallow(struct ssh *ssh, int sock, struct sshbuf *m)
712 struct passwd *pwent;
716 debug3_f("entering");
718 if (authctxt->attempt++ != 0)
719 fatal_f("multiple attempts for getpwnam");
721 if ((r = sshbuf_get_cstring(m, &authctxt->user, NULL)) != 0)
722 fatal_fr(r, "parse");
724 pwent = getpwnamallow(ssh, authctxt->user);
726 setproctitle("%s [priv]", pwent ? authctxt->user : "unknown");
731 if ((r = sshbuf_put_u8(m, 0)) != 0)
732 fatal_fr(r, "assemble fakepw");
733 authctxt->pw = fakepw();
738 authctxt->pw = pwent;
741 /* XXX send fake class/dir/shell, etc. */
742 if ((r = sshbuf_put_u8(m, 1)) != 0)
743 fatal_fr(r, "assemble ok");
746 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
749 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
752 if ((r = sshbuf_put_cstring(m, pwent->pw_name)) != 0 ||
753 (r = sshbuf_put_cstring(m, "*")) != 0 ||
754 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
755 (r = sshbuf_put_cstring(m, pwent->pw_gecos)) != 0 ||
757 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
758 (r = sshbuf_put_cstring(m, pwent->pw_class)) != 0 ||
760 (r = sshbuf_put_cstring(m, pwent->pw_dir)) != 0 ||
761 (r = sshbuf_put_cstring(m, pwent->pw_shell)) != 0)
762 fatal_fr(r, "assemble pw");
765 ssh_packet_set_log_preamble(ssh, "%suser %s",
766 authctxt->valid ? "authenticating" : "invalid ", authctxt->user);
767 if ((r = sshbuf_put_string(m, &options, sizeof(options))) != 0)
768 fatal_fr(r, "assemble options");
770 #define M_CP_STROPT(x) do { \
771 if (options.x != NULL && \
772 (r = sshbuf_put_cstring(m, options.x)) != 0) \
773 fatal_fr(r, "assemble %s", #x); \
775 #define M_CP_STRARRAYOPT(x, nx) do { \
776 for (i = 0; i < options.nx; i++) { \
777 if ((r = sshbuf_put_cstring(m, options.x[i])) != 0) \
778 fatal_fr(r, "assemble %s", #x); \
781 /* See comment in servconf.h */
782 COPY_MATCH_STRING_OPTS();
784 #undef M_CP_STRARRAYOPT
786 /* Create valid auth method lists */
787 if (auth2_setup_methods_lists(authctxt) != 0) {
789 * The monitor will continue long enough to let the child
790 * run to its packet_disconnect(), but it must not allow any
791 * authentication to succeed.
793 debug_f("no valid authentication method lists");
796 debug3_f("sending MONITOR_ANS_PWNAM: %d", allowed);
797 mm_request_send(sock, MONITOR_ANS_PWNAM, m);
799 /* Allow service/style information on the auth context */
800 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
801 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
805 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
811 int mm_answer_auth2_read_banner(struct ssh *ssh, int sock, struct sshbuf *m)
817 banner = auth2_read_banner();
818 if ((r = sshbuf_put_cstring(m, banner != NULL ? banner : "")) != 0)
819 fatal_fr(r, "assemble");
820 mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
827 mm_answer_authserv(struct ssh *ssh, int sock, struct sshbuf *m)
831 monitor_permit_authentications(1);
833 if ((r = sshbuf_get_cstring(m, &authctxt->service, NULL)) != 0 ||
834 (r = sshbuf_get_cstring(m, &authctxt->style, NULL)) != 0)
835 fatal_fr(r, "parse");
836 debug3_f("service=%s, style=%s", authctxt->service, authctxt->style);
838 if (strlen(authctxt->style) == 0) {
839 free(authctxt->style);
840 authctxt->style = NULL;
847 * Check that the key type appears in the supplied pattern list, ignoring
848 * mismatches in the signature algorithm. (Signature algorithm checks are
849 * performed in the unprivileged authentication code).
850 * Returns 1 on success, 0 otherwise.
853 key_base_type_match(const char *method, const struct sshkey *key,
856 char *s, *l, *ol = xstrdup(list);
860 for ((s = strsep(&l, ",")); s && *s != '\0'; (s = strsep(&l, ","))) {
861 if (sshkey_type_from_name(s) == key->type) {
867 error("%s key type %s is not in permitted list %s", method,
868 sshkey_ssh_name(key), list);
876 mm_answer_authpassword(struct ssh *ssh, int sock, struct sshbuf *m)
878 static int call_count;
880 int r, authenticated;
883 if (!options.password_authentication)
884 fatal_f("password authentication not enabled");
885 if ((r = sshbuf_get_cstring(m, &passwd, &plen)) != 0)
886 fatal_fr(r, "parse");
887 /* Only authenticate if the context is valid */
888 authenticated = options.password_authentication &&
889 auth_password(ssh, passwd);
890 freezero(passwd, plen);
893 if ((r = sshbuf_put_u32(m, authenticated)) != 0)
894 fatal_fr(r, "assemble");
896 if ((r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0)
897 fatal_fr(r, "assemble PAM");
900 debug3("%s: sending result %d", __func__, authenticated);
901 debug3_f("sending result %d", authenticated);
902 mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
905 if (plen == 0 && call_count == 1)
906 auth_method = "none";
908 auth_method = "password";
910 /* Causes monitor loop to terminate if authenticated */
911 return (authenticated);
916 mm_answer_bsdauthquery(struct ssh *ssh, int sock, struct sshbuf *m)
918 char *name, *infotxt;
919 u_int numprompts, *echo_on, success;
923 if (!options.kbd_interactive_authentication)
924 fatal_f("kbd-int authentication not enabled");
925 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
926 &prompts, &echo_on) < 0 ? 0 : 1;
929 if ((r = sshbuf_put_u32(m, success)) != 0)
930 fatal_fr(r, "assemble");
932 if ((r = sshbuf_put_cstring(m, prompts[0])) != 0)
933 fatal_fr(r, "assemble prompt");
936 debug3_f("sending challenge success: %u", success);
937 mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
950 mm_answer_bsdauthrespond(struct ssh *ssh, int sock, struct sshbuf *m)
955 if (!options.kbd_interactive_authentication)
956 fatal_f("kbd-int authentication not enabled");
957 if (authctxt->as == NULL)
958 fatal_f("no bsd auth session");
960 if ((r = sshbuf_get_cstring(m, &response, NULL)) != 0)
961 fatal_fr(r, "parse");
962 authok = options.kbd_interactive_authentication &&
963 auth_userresponse(authctxt->as, response, 0);
965 debug3_f("<%s> = <%d>", response, authok);
969 if ((r = sshbuf_put_u32(m, authok)) != 0)
970 fatal_fr(r, "assemble");
972 debug3_f("sending authenticated: %d", authok);
973 mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
975 auth_method = "keyboard-interactive";
976 auth_submethod = "bsdauth";
978 return (authok != 0);
984 mm_answer_pam_start(struct ssh *ssh, int sock, struct sshbuf *m)
986 if (!options.use_pam)
987 fatal("UsePAM not set, but ended up in %s anyway", __func__);
991 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
992 if (options.kbd_interactive_authentication)
993 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1);
999 mm_answer_pam_account(struct ssh *ssh, int sock, struct sshbuf *m)
1004 if (!options.use_pam)
1005 fatal("%s: PAM not enabled", __func__);
1007 ret = do_pam_account();
1009 if ((r = sshbuf_put_u32(m, ret)) != 0 ||
1010 (r = sshbuf_put_stringb(m, loginmsg)) != 0)
1011 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1013 mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
1018 static void *sshpam_ctxt, *sshpam_authok;
1019 extern KbdintDevice sshpam_device;
1022 mm_answer_pam_init_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
1027 debug3("%s", __func__);
1028 if (!options.kbd_interactive_authentication)
1029 fatal("%s: kbd-int authentication not enabled", __func__);
1030 if (sshpam_ctxt != NULL)
1031 fatal("%s: already called", __func__);
1032 sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
1033 sshpam_authok = NULL;
1035 if (sshpam_ctxt != NULL) {
1036 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
1037 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_QUERY, 1);
1040 if ((r = sshbuf_put_u32(m, ok)) != 0)
1041 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1042 mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
1047 mm_answer_pam_query(struct ssh *ssh, int sock, struct sshbuf *m)
1049 char *name = NULL, *info = NULL, **prompts = NULL;
1050 u_int i, num = 0, *echo_on = 0;
1053 debug3("%s", __func__);
1054 sshpam_authok = NULL;
1055 if (sshpam_ctxt == NULL)
1056 fatal("%s: no context", __func__);
1057 ret = (sshpam_device.query)(sshpam_ctxt, &name, &info,
1058 &num, &prompts, &echo_on);
1059 if (ret == 0 && num == 0)
1060 sshpam_authok = sshpam_ctxt;
1061 if (num > 1 || name == NULL || info == NULL)
1062 fatal("sshpam_device.query failed");
1063 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_RESPOND, 1);
1065 if ((r = sshbuf_put_u32(m, ret)) != 0 ||
1066 (r = sshbuf_put_cstring(m, name)) != 0 ||
1067 (r = sshbuf_put_cstring(m, info)) != 0 ||
1068 (r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0 ||
1069 (r = sshbuf_put_u32(m, num)) != 0)
1070 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1073 for (i = 0; i < num; ++i) {
1074 if ((r = sshbuf_put_cstring(m, prompts[i])) != 0 ||
1075 (r = sshbuf_put_u32(m, echo_on[i])) != 0)
1076 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1081 auth_method = "keyboard-interactive";
1082 auth_submethod = "pam";
1083 mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
1088 mm_answer_pam_respond(struct ssh *ssh, int sock, struct sshbuf *m)
1094 debug3("%s", __func__);
1095 if (sshpam_ctxt == NULL)
1096 fatal("%s: no context", __func__);
1097 sshpam_authok = NULL;
1098 if ((r = sshbuf_get_u32(m, &num)) != 0)
1099 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1100 if (num > PAM_MAX_NUM_MSG) {
1101 fatal_f("Too many PAM messages, got %u, expected <= %u",
1102 num, (unsigned)PAM_MAX_NUM_MSG);
1105 resp = xcalloc(num, sizeof(char *));
1106 for (i = 0; i < num; ++i) {
1107 if ((r = sshbuf_get_cstring(m, &(resp[i]), NULL)) != 0)
1108 fatal("%s: buffer error: %s",
1109 __func__, ssh_err(r));
1111 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
1112 for (i = 0; i < num; ++i)
1116 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
1119 if ((r = sshbuf_put_u32(m, ret)) != 0)
1120 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1121 mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
1122 auth_method = "keyboard-interactive";
1123 auth_submethod = "pam";
1125 sshpam_authok = sshpam_ctxt;
1130 mm_answer_pam_free_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
1132 int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt;
1134 debug3("%s", __func__);
1135 if (sshpam_ctxt == NULL)
1136 fatal("%s: no context", __func__);
1137 (sshpam_device.free_ctx)(sshpam_ctxt);
1138 sshpam_ctxt = sshpam_authok = NULL;
1140 mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
1141 /* Allow another attempt */
1142 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1);
1143 auth_method = "keyboard-interactive";
1144 auth_submethod = "pam";
1150 mm_answer_keyallowed(struct ssh *ssh, int sock, struct sshbuf *m)
1152 struct sshkey *key = NULL;
1153 char *cuser, *chost;
1154 u_int pubkey_auth_attempt;
1157 struct sshauthopt *opts = NULL;
1159 debug3_f("entering");
1160 if ((r = sshbuf_get_u32(m, &type)) != 0 ||
1161 (r = sshbuf_get_cstring(m, &cuser, NULL)) != 0 ||
1162 (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
1163 (r = sshkey_froms(m, &key)) != 0 ||
1164 (r = sshbuf_get_u32(m, &pubkey_auth_attempt)) != 0)
1165 fatal_fr(r, "parse");
1167 if (key != NULL && authctxt->valid) {
1170 auth_method = "publickey";
1171 if (!options.pubkey_authentication)
1173 if (auth2_key_already_used(authctxt, key))
1175 if (!key_base_type_match(auth_method, key,
1176 options.pubkey_accepted_algos))
1178 allowed = user_key_allowed(ssh, authctxt->pw, key,
1179 pubkey_auth_attempt, &opts);
1182 auth_method = "hostbased";
1183 if (!options.hostbased_authentication)
1185 if (auth2_key_already_used(authctxt, key))
1187 if (!key_base_type_match(auth_method, key,
1188 options.hostbased_accepted_algos))
1190 allowed = hostbased_key_allowed(ssh, authctxt->pw,
1192 auth2_record_info(authctxt,
1193 "client user \"%.100s\", client host \"%.100s\"",
1197 fatal_f("unknown key type %u", type);
1202 debug3_f("%s authentication%s: %s key is %s", auth_method,
1203 pubkey_auth_attempt ? "" : " test",
1204 (key == NULL || !authctxt->valid) ? "invalid" : sshkey_type(key),
1205 allowed ? "allowed" : "not allowed");
1207 auth2_record_key(authctxt, 0, key);
1209 /* clear temporarily storage (used by verify) */
1210 monitor_reset_key_state();
1213 /* Save temporarily for comparison in verify */
1214 if ((r = sshkey_to_blob(key, &key_blob, &key_bloblen)) != 0)
1215 fatal_fr(r, "sshkey_to_blob");
1216 key_blobtype = type;
1218 hostbased_cuser = cuser;
1219 hostbased_chost = chost;
1221 /* Log failed attempt */
1222 auth_log(ssh, 0, 0, auth_method, NULL);
1229 if ((r = sshbuf_put_u32(m, allowed)) != 0)
1230 fatal_fr(r, "assemble");
1231 if (opts != NULL && (r = sshauthopt_serialise(opts, m, 1)) != 0)
1232 fatal_fr(r, "sshauthopt_serialise");
1233 mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1236 sshauthopt_free(opts);
1242 monitor_valid_userblob(struct ssh *ssh, const u_char *data, u_int datalen)
1245 struct sshkey *hostkey = NULL;
1247 char *userstyle, *cp;
1250 int hostbound = 0, r, fail = 0;
1252 if ((b = sshbuf_from(data, datalen)) == NULL)
1253 fatal_f("sshbuf_from");
1255 if (ssh->compat & SSH_OLD_SESSIONID) {
1257 len = sshbuf_len(b);
1258 if ((session_id2 == NULL) ||
1259 (len < session_id2_len) ||
1260 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1262 if ((r = sshbuf_consume(b, session_id2_len)) != 0)
1263 fatal_fr(r, "consume");
1265 if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
1266 fatal_fr(r, "parse sessionid");
1267 if ((session_id2 == NULL) ||
1268 (len != session_id2_len) ||
1269 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1272 if ((r = sshbuf_get_u8(b, &type)) != 0)
1273 fatal_fr(r, "parse type");
1274 if (type != SSH2_MSG_USERAUTH_REQUEST)
1276 if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1277 fatal_fr(r, "parse userstyle");
1278 xasprintf(&userstyle, "%s%s%s", authctxt->user,
1279 authctxt->style ? ":" : "",
1280 authctxt->style ? authctxt->style : "");
1281 if (strcmp(userstyle, cp) != 0) {
1282 logit("wrong user name passed to monitor: "
1283 "expected %s != %.100s", userstyle, cp);
1288 if ((r = sshbuf_skip_string(b)) != 0 || /* service */
1289 (r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1290 fatal_fr(r, "parse method");
1291 if (strcmp("publickey", cp) != 0) {
1292 if (strcmp("publickey-hostbound-v00@openssh.com", cp) == 0)
1298 if ((r = sshbuf_get_u8(b, &type)) != 0)
1299 fatal_fr(r, "parse pktype");
1302 if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */
1303 (r = sshbuf_skip_string(b)) != 0 || /* pkblob */
1304 (hostbound && (r = sshkey_froms(b, &hostkey)) != 0))
1305 fatal_fr(r, "parse pk");
1306 if (sshbuf_len(b) != 0)
1309 if (hostkey != NULL) {
1311 * Ensure this is actually one of our hostkeys; unfortunately
1312 * can't check ssh->kex->initial_hostkey directly at this point
1313 * as packet state has not yet been exported to monitor.
1315 if (get_hostkey_index(hostkey, 1, ssh) == -1)
1316 fatal_f("hostbound hostkey does not match");
1317 sshkey_free(hostkey);
1323 monitor_valid_hostbasedblob(const u_char *data, u_int datalen,
1324 const char *cuser, const char *chost)
1328 char *cp, *userstyle;
1333 if ((b = sshbuf_from(data, datalen)) == NULL)
1334 fatal_f("sshbuf_new");
1335 if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
1336 fatal_fr(r, "parse sessionid");
1338 if ((session_id2 == NULL) ||
1339 (len != session_id2_len) ||
1340 (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1343 if ((r = sshbuf_get_u8(b, &type)) != 0)
1344 fatal_fr(r, "parse type");
1345 if (type != SSH2_MSG_USERAUTH_REQUEST)
1347 if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1348 fatal_fr(r, "parse userstyle");
1349 xasprintf(&userstyle, "%s%s%s", authctxt->user,
1350 authctxt->style ? ":" : "",
1351 authctxt->style ? authctxt->style : "");
1352 if (strcmp(userstyle, cp) != 0) {
1353 logit("wrong user name passed to monitor: "
1354 "expected %s != %.100s", userstyle, cp);
1359 if ((r = sshbuf_skip_string(b)) != 0 || /* service */
1360 (r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1361 fatal_fr(r, "parse method");
1362 if (strcmp(cp, "hostbased") != 0)
1365 if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */
1366 (r = sshbuf_skip_string(b)) != 0) /* pkblob */
1367 fatal_fr(r, "parse pk");
1369 /* verify client host, strip trailing dot if necessary */
1370 if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1371 fatal_fr(r, "parse host");
1372 if (((len = strlen(cp)) > 0) && cp[len - 1] == '.')
1374 if (strcmp(cp, chost) != 0)
1378 /* verify client user */
1379 if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
1380 fatal_fr(r, "parse ruser");
1381 if (strcmp(cp, cuser) != 0)
1385 if (sshbuf_len(b) != 0)
1392 mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m)
1395 const u_char *signature, *data, *blob;
1396 char *sigalg = NULL, *fp = NULL;
1397 size_t signaturelen, datalen, bloblen;
1398 int r, ret, req_presence = 0, req_verify = 0, valid_data = 0;
1400 struct sshkey_sig_details *sig_details = NULL;
1402 if ((r = sshbuf_get_string_direct(m, &blob, &bloblen)) != 0 ||
1403 (r = sshbuf_get_string_direct(m, &signature, &signaturelen)) != 0 ||
1404 (r = sshbuf_get_string_direct(m, &data, &datalen)) != 0 ||
1405 (r = sshbuf_get_cstring(m, &sigalg, NULL)) != 0)
1406 fatal_fr(r, "parse");
1408 if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1409 !monitor_allowed_key(blob, bloblen))
1410 fatal_f("bad key, not previously allowed");
1412 /* Empty signature algorithm means NULL. */
1413 if (*sigalg == '\0') {
1418 /* XXX use sshkey_froms here; need to change key_blob, etc. */
1419 if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
1420 fatal_fr(r, "parse key");
1422 switch (key_blobtype) {
1424 valid_data = monitor_valid_userblob(ssh, data, datalen);
1425 auth_method = "publickey";
1428 valid_data = monitor_valid_hostbasedblob(data, datalen,
1429 hostbased_cuser, hostbased_chost);
1430 auth_method = "hostbased";
1437 fatal_f("bad %s signature data blob",
1438 key_blobtype == MM_USERKEY ? "userkey" :
1439 (key_blobtype == MM_HOSTKEY ? "hostkey" : "unknown"));
1441 if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
1442 SSH_FP_DEFAULT)) == NULL)
1443 fatal_f("sshkey_fingerprint failed");
1445 ret = sshkey_verify(key, signature, signaturelen, data, datalen,
1446 sigalg, ssh->compat, &sig_details);
1447 debug3_f("%s %s signature using %s %s%s%s", auth_method,
1448 sshkey_type(key), sigalg == NULL ? "default" : sigalg,
1449 (ret == 0) ? "verified" : "unverified",
1450 (ret != 0) ? ": " : "", (ret != 0) ? ssh_err(ret) : "");
1452 if (ret == 0 && key_blobtype == MM_USERKEY && sig_details != NULL) {
1453 req_presence = (options.pubkey_auth_options &
1454 PUBKEYAUTH_TOUCH_REQUIRED) ||
1455 !key_opts->no_require_user_presence;
1457 (sig_details->sk_flags & SSH_SK_USER_PRESENCE_REQD) == 0) {
1458 error("public key %s %s signature for %s%s from %.128s "
1459 "port %d rejected: user presence "
1460 "(authenticator touch) requirement not met ",
1461 sshkey_type(key), fp,
1462 authctxt->valid ? "" : "invalid user ",
1463 authctxt->user, ssh_remote_ipaddr(ssh),
1464 ssh_remote_port(ssh));
1465 ret = SSH_ERR_SIGNATURE_INVALID;
1467 req_verify = (options.pubkey_auth_options &
1468 PUBKEYAUTH_VERIFY_REQUIRED) || key_opts->require_verify;
1470 (sig_details->sk_flags & SSH_SK_USER_VERIFICATION_REQD) == 0) {
1471 error("public key %s %s signature for %s%s from %.128s "
1472 "port %d rejected: user verification requirement "
1473 "not met ", sshkey_type(key), fp,
1474 authctxt->valid ? "" : "invalid user ",
1475 authctxt->user, ssh_remote_ipaddr(ssh),
1476 ssh_remote_port(ssh));
1477 ret = SSH_ERR_SIGNATURE_INVALID;
1480 auth2_record_key(authctxt, ret == 0, key);
1482 if (key_blobtype == MM_USERKEY)
1483 auth_activate_options(ssh, key_opts);
1484 monitor_reset_key_state();
1488 /* encode ret != 0 as positive integer, since we're sending u32 */
1489 encoded_ret = (ret != 0);
1490 if ((r = sshbuf_put_u32(m, encoded_ret)) != 0 ||
1491 (r = sshbuf_put_u8(m, sig_details != NULL)) != 0)
1492 fatal_fr(r, "assemble");
1493 if (sig_details != NULL) {
1494 if ((r = sshbuf_put_u32(m, sig_details->sk_counter)) != 0 ||
1495 (r = sshbuf_put_u8(m, sig_details->sk_flags)) != 0)
1496 fatal_fr(r, "assemble sk");
1498 sshkey_sig_details_free(sig_details);
1499 mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1509 mm_record_login(struct ssh *ssh, Session *s, struct passwd *pw)
1512 struct sockaddr_storage from;
1515 * Get IP address of client. If the connection is not a socket, let
1516 * the address be 0.0.0.0.
1518 memset(&from, 0, sizeof(from));
1519 fromlen = sizeof(from);
1520 if (ssh_packet_connection_is_on_socket(ssh)) {
1521 if (getpeername(ssh_packet_get_connection_in(ssh),
1522 (struct sockaddr *)&from, &fromlen) == -1) {
1523 debug("getpeername: %.100s", strerror(errno));
1527 /* Record that there was a login on that tty from the remote host. */
1528 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1529 session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns),
1530 (struct sockaddr *)&from, fromlen);
1534 mm_session_close(Session *s)
1536 debug3_f("session %d pid %ld", s->self, (long)s->pid);
1537 if (s->ttyfd != -1) {
1538 debug3_f("tty %s ptyfd %d", s->tty, s->ptyfd);
1539 session_pty_cleanup2(s);
1541 session_unused(s->self);
1545 mm_answer_pty(struct ssh *ssh, int sock, struct sshbuf *m)
1547 extern struct monitor *pmonitor;
1551 debug3_f("entering");
1557 s->authctxt = authctxt;
1558 s->pw = authctxt->pw;
1559 s->pid = pmonitor->m_pid;
1560 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1563 pty_setowner(authctxt->pw, s->tty);
1565 if ((r = sshbuf_put_u32(m, 1)) != 0 ||
1566 (r = sshbuf_put_cstring(m, s->tty)) != 0)
1567 fatal_fr(r, "assemble");
1569 /* We need to trick ttyslot */
1570 if (dup2(s->ttyfd, 0) == -1)
1573 mm_record_login(ssh, s, authctxt->pw);
1575 /* Now we can close the file descriptor again */
1578 /* send messages generated by record_login */
1579 if ((r = sshbuf_put_stringb(m, loginmsg)) != 0)
1580 fatal_fr(r, "assemble loginmsg");
1581 sshbuf_reset(loginmsg);
1583 mm_request_send(sock, MONITOR_ANS_PTY, m);
1585 if (mm_send_fd(sock, s->ptyfd) == -1 ||
1586 mm_send_fd(sock, s->ttyfd) == -1)
1587 fatal_f("send fds failed");
1589 /* make sure nothing uses fd 0 */
1590 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1591 fatal_f("open(/dev/null): %s", strerror(errno));
1593 error_f("fd0 %d != 0", fd0);
1595 /* slave side of pty is not needed */
1597 s->ttyfd = s->ptyfd;
1598 /* no need to dup() because nobody closes ptyfd */
1599 s->ptymaster = s->ptyfd;
1601 debug3_f("tty %s ptyfd %d", s->tty, s->ttyfd);
1607 mm_session_close(s);
1608 if ((r = sshbuf_put_u32(m, 0)) != 0)
1609 fatal_fr(r, "assemble 0");
1610 mm_request_send(sock, MONITOR_ANS_PTY, m);
1615 mm_answer_pty_cleanup(struct ssh *ssh, int sock, struct sshbuf *m)
1621 debug3_f("entering");
1623 if ((r = sshbuf_get_cstring(m, &tty, NULL)) != 0)
1624 fatal_fr(r, "parse tty");
1625 if ((s = session_by_tty(tty)) != NULL)
1626 mm_session_close(s);
1633 mm_answer_term(struct ssh *ssh, int sock, struct sshbuf *req)
1635 extern struct monitor *pmonitor;
1638 debug3_f("tearing down sessions");
1640 /* The child is terminating */
1641 session_destroy_all(ssh, &mm_session_close);
1644 if (options.use_pam)
1648 while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1652 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1654 /* Terminate process */
1658 #ifdef SSH_AUDIT_EVENTS
1659 /* Report that an audit event occurred */
1661 mm_answer_audit_event(struct ssh *ssh, int socket, struct sshbuf *m)
1664 ssh_audit_event_t event;
1667 debug3("%s entering", __func__);
1669 if ((r = sshbuf_get_u32(m, &n)) != 0)
1670 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1671 event = (ssh_audit_event_t)n;
1673 case SSH_AUTH_FAIL_PUBKEY:
1674 case SSH_AUTH_FAIL_HOSTBASED:
1675 case SSH_AUTH_FAIL_GSSAPI:
1676 case SSH_LOGIN_EXCEED_MAXTRIES:
1677 case SSH_LOGIN_ROOT_DENIED:
1678 case SSH_CONNECTION_CLOSE:
1679 case SSH_INVALID_USER:
1680 audit_event(ssh, event);
1683 fatal("Audit event type %d not permitted", event);
1690 mm_answer_audit_command(struct ssh *ssh, int socket, struct sshbuf *m)
1695 debug3("%s entering", __func__);
1696 if ((r = sshbuf_get_cstring(m, &cmd, NULL)) != 0)
1697 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1698 /* sanity check command, if so how? */
1699 audit_run_command(cmd);
1703 #endif /* SSH_AUDIT_EVENTS */
1706 monitor_clear_keystate(struct ssh *ssh, struct monitor *pmonitor)
1708 ssh_clear_newkeys(ssh, MODE_IN);
1709 ssh_clear_newkeys(ssh, MODE_OUT);
1710 sshbuf_free(child_state);
1715 monitor_apply_keystate(struct ssh *ssh, struct monitor *pmonitor)
1720 debug3_f("packet_set_state");
1721 if ((r = ssh_packet_set_state(ssh, child_state)) != 0)
1722 fatal_fr(r, "packet_set_state");
1723 sshbuf_free(child_state);
1725 if ((kex = ssh->kex) == NULL)
1726 fatal_f("internal error: ssh->kex == NULL");
1727 if (session_id2_len != sshbuf_len(ssh->kex->session_id)) {
1728 fatal_f("incorrect session id length %zu (expected %u)",
1729 sshbuf_len(ssh->kex->session_id), session_id2_len);
1731 if (memcmp(sshbuf_ptr(ssh->kex->session_id), session_id2,
1732 session_id2_len) != 0)
1733 fatal_f("session ID mismatch");
1734 /* XXX set callbacks */
1736 kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
1737 kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
1738 kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_server;
1739 kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_server;
1740 kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_server;
1741 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1742 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1743 # ifdef OPENSSL_HAS_ECC
1744 kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
1746 #endif /* WITH_OPENSSL */
1747 kex->kex[KEX_C25519_SHA256] = kex_gen_server;
1748 kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
1749 kex->load_host_public_key=&get_hostkey_public_by_type;
1750 kex->load_host_private_key=&get_hostkey_private_by_type;
1751 kex->host_key_index=&get_hostkey_index;
1752 kex->sign = sshd_hostkey_sign;
1755 /* This function requires careful sanity checking */
1758 mm_get_keystate(struct ssh *ssh, struct monitor *pmonitor)
1760 debug3_f("Waiting for new keys");
1762 if ((child_state = sshbuf_new()) == NULL)
1763 fatal_f("sshbuf_new failed");
1764 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT,
1766 debug3_f("GOT new keys");
1772 #define FD_CLOSEONEXEC(x) do { \
1773 if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
1774 fatal("fcntl(%d, F_SETFD)", x); \
1778 monitor_openfds(struct monitor *mon, int do_logfds)
1785 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1786 fatal_f("socketpair: %s", strerror(errno));
1788 if (setsockopt(pair[0], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
1789 error("setsockopt SO_ZEROIZE(0): %.100s", strerror(errno));
1790 if (setsockopt(pair[1], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
1791 error("setsockopt SO_ZEROIZE(1): %.100s", strerror(errno));
1793 FD_CLOSEONEXEC(pair[0]);
1794 FD_CLOSEONEXEC(pair[1]);
1795 mon->m_recvfd = pair[0];
1796 mon->m_sendfd = pair[1];
1799 if (pipe(pair) == -1)
1800 fatal_f("pipe: %s", strerror(errno));
1801 FD_CLOSEONEXEC(pair[0]);
1802 FD_CLOSEONEXEC(pair[1]);
1803 mon->m_log_recvfd = pair[0];
1804 mon->m_log_sendfd = pair[1];
1806 mon->m_log_recvfd = mon->m_log_sendfd = -1;
1809 #define MM_MEMSIZE 65536
1814 struct monitor *mon;
1816 mon = xcalloc(1, sizeof(*mon));
1817 monitor_openfds(mon, 1);
1823 monitor_reinit(struct monitor *mon)
1825 monitor_openfds(mon, 0);
1830 mm_answer_gss_setup_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
1838 if (!options.gss_authentication)
1839 fatal_f("GSSAPI authentication not enabled");
1841 if ((r = sshbuf_get_string(m, &p, &len)) != 0)
1842 fatal_fr(r, "parse");
1846 major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1848 free(goid.elements);
1851 if ((r = sshbuf_put_u32(m, major)) != 0)
1852 fatal_fr(r, "assemble");
1854 mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1856 /* Now we have a context, enable the step */
1857 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1863 mm_answer_gss_accept_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
1866 gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1867 OM_uint32 major, minor;
1868 OM_uint32 flags = 0; /* GSI needs this */
1871 if (!options.gss_authentication)
1872 fatal_f("GSSAPI authentication not enabled");
1874 if ((r = ssh_gssapi_get_buffer_desc(m, &in)) != 0)
1875 fatal_fr(r, "ssh_gssapi_get_buffer_desc");
1876 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1880 if ((r = sshbuf_put_u32(m, major)) != 0 ||
1881 (r = sshbuf_put_string(m, out.value, out.length)) != 0 ||
1882 (r = sshbuf_put_u32(m, flags)) != 0)
1883 fatal_fr(r, "assemble");
1884 mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1886 gss_release_buffer(&minor, &out);
1888 if (major == GSS_S_COMPLETE) {
1889 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1890 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1891 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1897 mm_answer_gss_checkmic(struct ssh *ssh, int sock, struct sshbuf *m)
1899 gss_buffer_desc gssbuf, mic;
1903 if (!options.gss_authentication)
1904 fatal_f("GSSAPI authentication not enabled");
1906 if ((r = ssh_gssapi_get_buffer_desc(m, &gssbuf)) != 0 ||
1907 (r = ssh_gssapi_get_buffer_desc(m, &mic)) != 0)
1908 fatal_fr(r, "ssh_gssapi_get_buffer_desc");
1910 ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1916 if ((r = sshbuf_put_u32(m, ret)) != 0)
1917 fatal_fr(r, "assemble");
1919 mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1921 if (!GSS_ERROR(ret))
1922 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1928 mm_answer_gss_userok(struct ssh *ssh, int sock, struct sshbuf *m)
1930 int r, authenticated;
1931 const char *displayname;
1933 if (!options.gss_authentication)
1934 fatal_f("GSSAPI authentication not enabled");
1936 authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1939 if ((r = sshbuf_put_u32(m, authenticated)) != 0)
1940 fatal_fr(r, "assemble");
1942 debug3_f("sending result %d", authenticated);
1943 mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1945 auth_method = "gssapi-with-mic";
1947 if ((displayname = ssh_gssapi_displayname()) != NULL)
1948 auth2_record_info(authctxt, "%s", displayname);
1950 /* Monitor loop will terminate if authenticated */
1951 return (authenticated);