2 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
3 * Copyright 2002 Markus Friedl <markus@openbsd.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 RCSID("$OpenBSD: monitor.c,v 1.37 2003/04/02 09:48:07 markus Exp $");
30 #include <openssl/dh.h>
42 #include "auth-options.h"
51 #include "monitor_mm.h"
52 #include "monitor_wrap.h"
53 #include "monitor_fdpass.h"
63 extern ServerOptions options;
64 extern u_int utmp_len;
65 extern Newkeys *current_keys[];
66 extern z_stream incoming_stream;
67 extern z_stream outgoing_stream;
68 extern u_char session_id[];
69 extern Buffer input, output;
70 extern Buffer auth_debug;
71 extern int auth_debug_init;
73 /* State exported from the child */
96 /* Functions on the montior that answer unprivileged requests */
98 int mm_answer_moduli(int, Buffer *);
99 int mm_answer_sign(int, Buffer *);
100 int mm_answer_pwnamallow(int, Buffer *);
101 int mm_answer_auth2_read_banner(int, Buffer *);
102 int mm_answer_authserv(int, Buffer *);
103 int mm_answer_authpassword(int, Buffer *);
104 int mm_answer_bsdauthquery(int, Buffer *);
105 int mm_answer_bsdauthrespond(int, Buffer *);
106 int mm_answer_skeyquery(int, Buffer *);
107 int mm_answer_skeyrespond(int, Buffer *);
108 int mm_answer_keyallowed(int, Buffer *);
109 int mm_answer_keyverify(int, Buffer *);
110 int mm_answer_pty(int, Buffer *);
111 int mm_answer_pty_cleanup(int, Buffer *);
112 int mm_answer_term(int, Buffer *);
113 int mm_answer_rsa_keyallowed(int, Buffer *);
114 int mm_answer_rsa_challenge(int, Buffer *);
115 int mm_answer_rsa_response(int, Buffer *);
116 int mm_answer_sesskey(int, Buffer *);
117 int mm_answer_sessid(int, Buffer *);
120 int mm_answer_pam_start(int, Buffer *);
124 int mm_answer_krb4(int, Buffer *);
127 int mm_answer_krb5(int, Buffer *);
130 static Authctxt *authctxt;
131 static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
133 /* local state for key verify */
134 static u_char *key_blob = NULL;
135 static u_int key_bloblen = 0;
136 static int key_blobtype = MM_NOKEY;
137 static char *hostbased_cuser = NULL;
138 static char *hostbased_chost = NULL;
139 static char *auth_method = "unknown";
140 static int session_id2_len = 0;
141 static u_char *session_id2 = NULL;
144 enum monitor_reqtype type;
146 int (*f)(int, Buffer *);
149 #define MON_ISAUTH 0x0004 /* Required for Authentication */
150 #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
151 #define MON_ONCE 0x0010 /* Disable after calling */
153 #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
155 #define MON_PERMIT 0x1000 /* Request is permitted */
157 struct mon_table mon_dispatch_proto20[] = {
158 {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
159 {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
160 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
161 {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
162 {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
163 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
165 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
168 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
169 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
172 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
173 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
175 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
176 {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
180 struct mon_table mon_dispatch_postauth20[] = {
181 {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
182 {MONITOR_REQ_SIGN, 0, mm_answer_sign},
183 {MONITOR_REQ_PTY, 0, mm_answer_pty},
184 {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
185 {MONITOR_REQ_TERM, 0, mm_answer_term},
189 struct mon_table mon_dispatch_proto15[] = {
190 {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
191 {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
192 {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
193 {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
194 {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed},
195 {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
196 {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
197 {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
199 {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
200 {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
203 {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
204 {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
207 {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
210 {MONITOR_REQ_KRB4, MON_ONCE|MON_AUTH, mm_answer_krb4},
213 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5},
218 struct mon_table mon_dispatch_postauth15[] = {
219 {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
220 {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
221 {MONITOR_REQ_TERM, 0, mm_answer_term},
225 struct mon_table *mon_dispatch;
227 /* Specifies if a certain message is allowed at the moment */
230 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
232 while (ent->f != NULL) {
233 if (ent->type == type) {
234 ent->flags &= ~MON_PERMIT;
235 ent->flags |= permit ? MON_PERMIT : 0;
243 monitor_permit_authentications(int permit)
245 struct mon_table *ent = mon_dispatch;
247 while (ent->f != NULL) {
248 if (ent->flags & MON_AUTH) {
249 ent->flags &= ~MON_PERMIT;
250 ent->flags |= permit ? MON_PERMIT : 0;
257 monitor_child_preauth(struct monitor *pmonitor)
259 struct mon_table *ent;
260 int authenticated = 0;
262 debug3("preauth child monitor started");
265 mon_dispatch = mon_dispatch_proto20;
267 /* Permit requests for moduli and signatures */
268 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
269 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
271 mon_dispatch = mon_dispatch_proto15;
273 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
276 authctxt = authctxt_new();
278 /* The first few requests do not require asynchronous access */
279 while (!authenticated) {
280 authenticated = monitor_read(pmonitor, mon_dispatch, &ent);
282 if (!(ent->flags & MON_AUTHDECIDE))
283 fatal("%s: unexpected authentication from %d",
284 __func__, ent->type);
285 if (authctxt->pw->pw_uid == 0 &&
286 !auth_root_allowed(auth_method))
289 if (!do_pam_account(authctxt->pw->pw_name, NULL))
294 if (ent->flags & MON_AUTHDECIDE) {
295 auth_log(authctxt, authenticated, auth_method,
296 compat20 ? " ssh2" : "");
298 authctxt->failures++;
302 if (!authctxt->valid)
303 fatal("%s: authenticated invalid user", __func__);
305 debug("%s: %s has been authenticated by privileged process",
306 __func__, authctxt->user);
308 mm_get_keystate(pmonitor);
314 monitor_child_postauth(struct monitor *pmonitor)
317 mon_dispatch = mon_dispatch_postauth20;
319 /* Permit requests for moduli and signatures */
320 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
321 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
322 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
325 mon_dispatch = mon_dispatch_postauth15;
326 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
329 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
330 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
334 monitor_read(pmonitor, mon_dispatch, NULL);
338 monitor_sync(struct monitor *pmonitor)
340 if (options.compression) {
341 /* The member allocation is not visible, so sync it */
342 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
347 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
348 struct mon_table **pent)
356 mm_request_receive(pmonitor->m_sendfd, &m);
357 type = buffer_get_char(&m);
359 debug3("%s: checking request %d", __func__, type);
361 while (ent->f != NULL) {
362 if (ent->type == type)
367 if (ent->f != NULL) {
368 if (!(ent->flags & MON_PERMIT))
369 fatal("%s: unpermitted request %d", __func__,
371 ret = (*ent->f)(pmonitor->m_sendfd, &m);
374 /* The child may use this request only once, disable it */
375 if (ent->flags & MON_ONCE) {
376 debug2("%s: %d used once, disabling now", __func__,
378 ent->flags &= ~MON_PERMIT;
387 fatal("%s: unsupported request: %d", __func__, type);
393 /* allowed key state */
395 monitor_allowed_key(u_char *blob, u_int bloblen)
397 /* make sure key is allowed */
398 if (key_blob == NULL || key_bloblen != bloblen ||
399 memcmp(key_blob, blob, key_bloblen))
405 monitor_reset_key_state(void)
408 if (key_blob != NULL)
410 if (hostbased_cuser != NULL)
411 xfree(hostbased_cuser);
412 if (hostbased_chost != NULL)
413 xfree(hostbased_chost);
416 key_blobtype = MM_NOKEY;
417 hostbased_cuser = NULL;
418 hostbased_chost = NULL;
422 mm_answer_moduli(int socket, Buffer *m)
427 min = buffer_get_int(m);
428 want = buffer_get_int(m);
429 max = buffer_get_int(m);
431 debug3("%s: got parameters: %d %d %d",
432 __func__, min, want, max);
433 /* We need to check here, too, in case the child got corrupted */
434 if (max < min || want < min || max < want)
435 fatal("%s: bad parameters: %d %d %d",
436 __func__, min, want, max);
440 dh = choose_dh(min, want, max);
442 buffer_put_char(m, 0);
445 /* Send first bignum */
446 buffer_put_char(m, 1);
447 buffer_put_bignum2(m, dh->p);
448 buffer_put_bignum2(m, dh->g);
452 mm_request_send(socket, MONITOR_ANS_MODULI, m);
457 mm_answer_sign(int socket, Buffer *m)
462 u_int siglen, datlen;
465 debug3("%s", __func__);
467 keyid = buffer_get_int(m);
468 p = buffer_get_string(m, &datlen);
471 fatal("%s: data length incorrect: %u", __func__, datlen);
473 /* save session id, it will be passed on the first call */
474 if (session_id2_len == 0) {
475 session_id2_len = datlen;
476 session_id2 = xmalloc(session_id2_len);
477 memcpy(session_id2, p, session_id2_len);
480 if ((key = get_hostkey_by_index(keyid)) == NULL)
481 fatal("%s: no hostkey from index %d", __func__, keyid);
482 if (key_sign(key, &signature, &siglen, p, datlen) < 0)
483 fatal("%s: key_sign failed", __func__);
485 debug3("%s: signature %p(%u)", __func__, signature, siglen);
488 buffer_put_string(m, signature, siglen);
493 mm_request_send(socket, MONITOR_ANS_SIGN, m);
495 /* Turn on permissions for getpwnam */
496 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
501 /* Retrieves the password entry and also checks if the user is permitted */
504 mm_answer_pwnamallow(int socket, Buffer *m)
507 struct passwd *pwent;
510 debug3("%s", __func__);
512 if (authctxt->attempt++ != 0)
513 fatal("%s: multiple attempts for getpwnam", __func__);
515 login = buffer_get_string(m, NULL);
517 pwent = getpwnamallow(login);
519 authctxt->user = xstrdup(login);
520 setproctitle("%s [priv]", pwent ? login : "unknown");
526 buffer_put_char(m, 0);
531 authctxt->pw = pwent;
534 buffer_put_char(m, 1);
535 buffer_put_string(m, pwent, sizeof(struct passwd));
536 buffer_put_cstring(m, pwent->pw_name);
537 buffer_put_cstring(m, "*");
538 buffer_put_cstring(m, pwent->pw_gecos);
539 #ifdef HAVE_PW_CLASS_IN_PASSWD
540 buffer_put_cstring(m, pwent->pw_class);
542 buffer_put_cstring(m, pwent->pw_dir);
543 buffer_put_cstring(m, pwent->pw_shell);
546 debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
547 mm_request_send(socket, MONITOR_ANS_PWNAM, m);
549 /* For SSHv1 allow authentication now */
551 monitor_permit_authentications(1);
553 /* Allow service/style information on the auth context */
554 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
555 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
559 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
565 int mm_answer_auth2_read_banner(int socket, Buffer *m)
570 banner = auth2_read_banner();
571 buffer_put_cstring(m, banner != NULL ? banner : "");
572 mm_request_send(socket, MONITOR_ANS_AUTH2_READ_BANNER, m);
581 mm_answer_authserv(int socket, Buffer *m)
583 monitor_permit_authentications(1);
585 authctxt->service = buffer_get_string(m, NULL);
586 authctxt->style = buffer_get_string(m, NULL);
587 debug3("%s: service=%s, style=%s",
588 __func__, authctxt->service, authctxt->style);
590 if (strlen(authctxt->style) == 0) {
591 xfree(authctxt->style);
592 authctxt->style = NULL;
599 mm_answer_authpassword(int socket, Buffer *m)
601 static int call_count;
606 passwd = buffer_get_string(m, &plen);
607 /* Only authenticate if the context is valid */
608 authenticated = options.password_authentication &&
609 authctxt->valid && auth_password(authctxt, passwd);
610 memset(passwd, 0, strlen(passwd));
614 buffer_put_int(m, authenticated);
616 debug3("%s: sending result %d", __func__, authenticated);
617 mm_request_send(socket, MONITOR_ANS_AUTHPASSWORD, m);
620 if (plen == 0 && call_count == 1)
621 auth_method = "none";
623 auth_method = "password";
625 /* Causes monitor loop to terminate if authenticated */
626 return (authenticated);
631 mm_answer_bsdauthquery(int socket, Buffer *m)
633 char *name, *infotxt;
639 success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
640 &prompts, &echo_on) < 0 ? 0 : 1;
643 buffer_put_int(m, success);
645 buffer_put_cstring(m, prompts[0]);
647 debug3("%s: sending challenge success: %u", __func__, success);
648 mm_request_send(socket, MONITOR_ANS_BSDAUTHQUERY, m);
661 mm_answer_bsdauthrespond(int socket, Buffer *m)
666 if (authctxt->as == 0)
667 fatal("%s: no bsd auth session", __func__);
669 response = buffer_get_string(m, NULL);
670 authok = options.challenge_response_authentication &&
671 auth_userresponse(authctxt->as, response, 0);
673 debug3("%s: <%s> = <%d>", __func__, response, authok);
677 buffer_put_int(m, authok);
679 debug3("%s: sending authenticated: %d", __func__, authok);
680 mm_request_send(socket, MONITOR_ANS_BSDAUTHRESPOND, m);
682 auth_method = "bsdauth";
684 return (authok != 0);
690 mm_answer_skeyquery(int socket, Buffer *m)
693 char challenge[1024];
696 success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1;
699 buffer_put_int(m, success);
701 buffer_put_cstring(m, challenge);
703 debug3("%s: sending challenge success: %u", __func__, success);
704 mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m);
710 mm_answer_skeyrespond(int socket, Buffer *m)
715 response = buffer_get_string(m, NULL);
717 authok = (options.challenge_response_authentication &&
719 skey_haskey(authctxt->pw->pw_name) == 0 &&
720 skey_passcheck(authctxt->pw->pw_name, response) != -1);
725 buffer_put_int(m, authok);
727 debug3("%s: sending authenticated: %d", __func__, authok);
728 mm_request_send(socket, MONITOR_ANS_SKEYRESPOND, m);
730 auth_method = "skey";
732 return (authok != 0);
738 mm_answer_pam_start(int socket, Buffer *m)
742 user = buffer_get_string(m, NULL);
753 mm_append_debug(Buffer *m)
755 if (auth_debug_init && buffer_len(&auth_debug)) {
756 debug3("%s: Appending debug messages for child", __func__);
757 buffer_append(m, buffer_ptr(&auth_debug),
758 buffer_len(&auth_debug));
759 buffer_clear(&auth_debug);
764 mm_answer_keyallowed(int socket, Buffer *m)
770 enum mm_keytype type = 0;
773 debug3("%s entering", __func__);
775 type = buffer_get_int(m);
776 cuser = buffer_get_string(m, NULL);
777 chost = buffer_get_string(m, NULL);
778 blob = buffer_get_string(m, &bloblen);
780 key = key_from_blob(blob, bloblen);
782 if ((compat20 && type == MM_RSAHOSTKEY) ||
783 (!compat20 && type != MM_RSAHOSTKEY))
784 fatal("%s: key type and protocol mismatch", __func__);
786 debug3("%s: key_from_blob: %p", __func__, key);
788 if (key != NULL && authctxt->pw != NULL) {
791 allowed = options.pubkey_authentication &&
792 user_key_allowed(authctxt->pw, key);
795 allowed = options.hostbased_authentication &&
796 hostbased_key_allowed(authctxt->pw,
800 key->type = KEY_RSA1; /* XXX */
801 allowed = options.rhosts_rsa_authentication &&
802 auth_rhosts_rsa_key_allowed(authctxt->pw,
806 fatal("%s: unknown key type %d", __func__, type);
813 /* clear temporarily storage (used by verify) */
814 monitor_reset_key_state();
817 /* Save temporarily for comparison in verify */
819 key_bloblen = bloblen;
821 hostbased_cuser = cuser;
822 hostbased_chost = chost;
825 debug3("%s: key %p is %s",
826 __func__, key, allowed ? "allowed" : "disallowed");
829 buffer_put_int(m, allowed);
830 buffer_put_int(m, forced_command != NULL);
834 mm_request_send(socket, MONITOR_ANS_KEYALLOWED, m);
836 if (type == MM_RSAHOSTKEY)
837 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
843 monitor_valid_userblob(u_char *data, u_int datalen)
851 buffer_append(&b, data, datalen);
853 if (datafellows & SSH_OLD_SESSIONID) {
855 len = buffer_len(&b);
856 if ((session_id2 == NULL) ||
857 (len < session_id2_len) ||
858 (memcmp(p, session_id2, session_id2_len) != 0))
860 buffer_consume(&b, session_id2_len);
862 p = buffer_get_string(&b, &len);
863 if ((session_id2 == NULL) ||
864 (len != session_id2_len) ||
865 (memcmp(p, session_id2, session_id2_len) != 0))
869 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
871 p = buffer_get_string(&b, NULL);
872 if (strcmp(authctxt->user, p) != 0) {
873 logit("wrong user name passed to monitor: expected %s != %.100s",
878 buffer_skip_string(&b);
879 if (datafellows & SSH_BUG_PKAUTH) {
880 if (!buffer_get_char(&b))
883 p = buffer_get_string(&b, NULL);
884 if (strcmp("publickey", p) != 0)
887 if (!buffer_get_char(&b))
889 buffer_skip_string(&b);
891 buffer_skip_string(&b);
892 if (buffer_len(&b) != 0)
899 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
908 buffer_append(&b, data, datalen);
910 p = buffer_get_string(&b, &len);
911 if ((session_id2 == NULL) ||
912 (len != session_id2_len) ||
913 (memcmp(p, session_id2, session_id2_len) != 0))
917 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
919 p = buffer_get_string(&b, NULL);
920 if (strcmp(authctxt->user, p) != 0) {
921 logit("wrong user name passed to monitor: expected %s != %.100s",
926 buffer_skip_string(&b); /* service */
927 p = buffer_get_string(&b, NULL);
928 if (strcmp(p, "hostbased") != 0)
931 buffer_skip_string(&b); /* pkalg */
932 buffer_skip_string(&b); /* pkblob */
934 /* verify client host, strip trailing dot if necessary */
935 p = buffer_get_string(&b, NULL);
936 if (((len = strlen(p)) > 0) && p[len - 1] == '.')
938 if (strcmp(p, chost) != 0)
942 /* verify client user */
943 p = buffer_get_string(&b, NULL);
944 if (strcmp(p, cuser) != 0)
948 if (buffer_len(&b) != 0)
955 mm_answer_keyverify(int socket, Buffer *m)
958 u_char *signature, *data, *blob;
959 u_int signaturelen, datalen, bloblen;
963 blob = buffer_get_string(m, &bloblen);
964 signature = buffer_get_string(m, &signaturelen);
965 data = buffer_get_string(m, &datalen);
967 if (hostbased_cuser == NULL || hostbased_chost == NULL ||
968 !monitor_allowed_key(blob, bloblen))
969 fatal("%s: bad key, not previously allowed", __func__);
971 key = key_from_blob(blob, bloblen);
973 fatal("%s: bad public key blob", __func__);
975 switch (key_blobtype) {
977 valid_data = monitor_valid_userblob(data, datalen);
980 valid_data = monitor_valid_hostbasedblob(data, datalen,
981 hostbased_cuser, hostbased_chost);
988 fatal("%s: bad signature data blob", __func__);
990 verified = key_verify(key, signature, signaturelen, data, datalen);
991 debug3("%s: key %p signature %s",
992 __func__, key, verified ? "verified" : "unverified");
999 auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1001 monitor_reset_key_state();
1004 buffer_put_int(m, verified);
1005 mm_request_send(socket, MONITOR_ANS_KEYVERIFY, m);
1011 mm_record_login(Session *s, struct passwd *pw)
1014 struct sockaddr_storage from;
1017 * Get IP address of client. If the connection is not a socket, let
1018 * the address be 0.0.0.0.
1020 memset(&from, 0, sizeof(from));
1021 fromlen = sizeof(from);
1022 if (packet_connection_is_on_socket()) {
1023 if (getpeername(packet_get_connection_in(),
1024 (struct sockaddr *) & from, &fromlen) < 0) {
1025 debug("getpeername: %.100s", strerror(errno));
1029 /* Record that there was a login on that tty from the remote host. */
1030 record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1031 get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping),
1032 (struct sockaddr *)&from, fromlen);
1036 mm_session_close(Session *s)
1038 debug3("%s: session %d pid %d", __func__, s->self, s->pid);
1039 if (s->ttyfd != -1) {
1040 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1041 fatal_remove_cleanup(session_pty_cleanup2, (void *)s);
1042 session_pty_cleanup2(s);
1048 mm_answer_pty(int socket, Buffer *m)
1050 extern struct monitor *pmonitor;
1054 debug3("%s entering", __func__);
1060 s->authctxt = authctxt;
1061 s->pw = authctxt->pw;
1062 s->pid = pmonitor->m_pid;
1063 res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1066 fatal_add_cleanup(session_pty_cleanup2, (void *)s);
1067 pty_setowner(authctxt->pw, s->tty);
1069 buffer_put_int(m, 1);
1070 buffer_put_cstring(m, s->tty);
1071 mm_request_send(socket, MONITOR_ANS_PTY, m);
1073 mm_send_fd(socket, s->ptyfd);
1074 mm_send_fd(socket, s->ttyfd);
1076 /* We need to trick ttyslot */
1077 if (dup2(s->ttyfd, 0) == -1)
1078 fatal("%s: dup2", __func__);
1080 mm_record_login(s, authctxt->pw);
1082 /* Now we can close the file descriptor again */
1085 /* make sure nothing uses fd 0 */
1086 if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1087 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1089 error("%s: fd0 %d != 0", __func__, fd0);
1091 /* slave is not needed */
1093 s->ttyfd = s->ptyfd;
1094 /* no need to dup() because nobody closes ptyfd */
1095 s->ptymaster = s->ptyfd;
1097 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1103 mm_session_close(s);
1104 buffer_put_int(m, 0);
1105 mm_request_send(socket, MONITOR_ANS_PTY, m);
1110 mm_answer_pty_cleanup(int socket, Buffer *m)
1115 debug3("%s entering", __func__);
1117 tty = buffer_get_string(m, NULL);
1118 if ((s = session_by_tty(tty)) != NULL)
1119 mm_session_close(s);
1126 mm_answer_sesskey(int socket, Buffer *m)
1131 /* Turn off permissions */
1132 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
1134 if ((p = BN_new()) == NULL)
1135 fatal("%s: BN_new", __func__);
1137 buffer_get_bignum2(m, p);
1139 rsafail = ssh1_session_key(p);
1142 buffer_put_int(m, rsafail);
1143 buffer_put_bignum2(m, p);
1147 mm_request_send(socket, MONITOR_ANS_SESSKEY, m);
1149 /* Turn on permissions for sessid passing */
1150 monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1156 mm_answer_sessid(int socket, Buffer *m)
1160 debug3("%s entering", __func__);
1162 if (buffer_len(m) != 16)
1163 fatal("%s: bad ssh1 session id", __func__);
1164 for (i = 0; i < 16; i++)
1165 session_id[i] = buffer_get_char(m);
1167 /* Turn on permissions for getpwnam */
1168 monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1174 mm_answer_rsa_keyallowed(int socket, Buffer *m)
1178 u_char *blob = NULL;
1182 debug3("%s entering", __func__);
1184 if (options.rsa_authentication && authctxt->valid) {
1185 if ((client_n = BN_new()) == NULL)
1186 fatal("%s: BN_new", __func__);
1187 buffer_get_bignum2(m, client_n);
1188 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1189 BN_clear_free(client_n);
1192 buffer_put_int(m, allowed);
1193 buffer_put_int(m, forced_command != NULL);
1195 /* clear temporarily storage (used by generate challenge) */
1196 monitor_reset_key_state();
1198 if (allowed && key != NULL) {
1199 key->type = KEY_RSA; /* cheat for key_to_blob */
1200 if (key_to_blob(key, &blob, &blen) == 0)
1201 fatal("%s: key_to_blob failed", __func__);
1202 buffer_put_string(m, blob, blen);
1204 /* Save temporarily for comparison in verify */
1207 key_blobtype = MM_RSAUSERKEY;
1214 mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m);
1216 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1217 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1222 mm_answer_rsa_challenge(int socket, Buffer *m)
1228 debug3("%s entering", __func__);
1230 if (!authctxt->valid)
1231 fatal("%s: authctxt not valid", __func__);
1232 blob = buffer_get_string(m, &blen);
1233 if (!monitor_allowed_key(blob, blen))
1234 fatal("%s: bad key, not previously allowed", __func__);
1235 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1236 fatal("%s: key type mismatch", __func__);
1237 if ((key = key_from_blob(blob, blen)) == NULL)
1238 fatal("%s: received bad key", __func__);
1241 BN_clear_free(ssh1_challenge);
1242 ssh1_challenge = auth_rsa_generate_challenge(key);
1245 buffer_put_bignum2(m, ssh1_challenge);
1247 debug3("%s sending reply", __func__);
1248 mm_request_send(socket, MONITOR_ANS_RSACHALLENGE, m);
1250 monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1258 mm_answer_rsa_response(int socket, Buffer *m)
1261 u_char *blob, *response;
1265 debug3("%s entering", __func__);
1267 if (!authctxt->valid)
1268 fatal("%s: authctxt not valid", __func__);
1269 if (ssh1_challenge == NULL)
1270 fatal("%s: no ssh1_challenge", __func__);
1272 blob = buffer_get_string(m, &blen);
1273 if (!monitor_allowed_key(blob, blen))
1274 fatal("%s: bad key, not previously allowed", __func__);
1275 if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1276 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1277 if ((key = key_from_blob(blob, blen)) == NULL)
1278 fatal("%s: received bad key", __func__);
1279 response = buffer_get_string(m, &len);
1281 fatal("%s: received bad response to challenge", __func__);
1282 success = auth_rsa_verify_response(key, ssh1_challenge, response);
1288 auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1291 BN_clear_free(ssh1_challenge);
1292 ssh1_challenge = NULL;
1293 monitor_reset_key_state();
1296 buffer_put_int(m, success);
1297 mm_request_send(socket, MONITOR_ANS_RSARESPONSE, m);
1304 mm_answer_krb4(int socket, Buffer *m)
1306 KTEXT_ST auth, reply;
1311 reply.length = auth.length = 0;
1313 p = buffer_get_string(m, &alen);
1314 if (alen >= MAX_KTXT_LEN)
1315 fatal("%s: auth too large", __func__);
1316 memcpy(auth.dat, p, alen);
1321 success = options.kerberos_authentication &&
1323 auth_krb4(authctxt, &auth, &client, &reply);
1325 memset(auth.dat, 0, alen);
1327 buffer_put_int(m, success);
1330 buffer_put_cstring(m, client);
1331 buffer_put_string(m, reply.dat, reply.length);
1335 memset(reply.dat, 0, reply.length);
1338 debug3("%s: sending result %d", __func__, success);
1339 mm_request_send(socket, MONITOR_ANS_KRB4, m);
1341 auth_method = "kerberos";
1343 /* Causes monitor loop to terminate if authenticated */
1350 mm_answer_krb5(int socket, Buffer *m)
1352 krb5_data tkt, reply;
1357 /* use temporary var to avoid size issues on 64bit arch */
1358 tkt.data = buffer_get_string(m, &len);
1361 success = options.kerberos_authentication &&
1363 auth_krb5(authctxt, &tkt, &client_user, &reply);
1369 buffer_put_int(m, success);
1372 buffer_put_cstring(m, client_user);
1373 buffer_put_string(m, reply.data, reply.length);
1379 mm_request_send(socket, MONITOR_ANS_KRB5, m);
1386 mm_answer_term(int socket, Buffer *req)
1388 extern struct monitor *pmonitor;
1391 debug3("%s: tearing down sessions", __func__);
1393 /* The child is terminating */
1394 session_destroy_all(&mm_session_close);
1396 while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1400 res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1402 /* Terminate process */
1407 monitor_apply_keystate(struct monitor *pmonitor)
1410 set_newkeys(MODE_IN);
1411 set_newkeys(MODE_OUT);
1413 packet_set_protocol_flags(child_state.ssh1protoflags);
1414 packet_set_encryption_key(child_state.ssh1key,
1415 child_state.ssh1keylen, child_state.ssh1cipher);
1416 xfree(child_state.ssh1key);
1419 /* for rc4 and other stateful ciphers */
1420 packet_set_keycontext(MODE_OUT, child_state.keyout);
1421 xfree(child_state.keyout);
1422 packet_set_keycontext(MODE_IN, child_state.keyin);
1423 xfree(child_state.keyin);
1426 packet_set_iv(MODE_OUT, child_state.ivout);
1427 xfree(child_state.ivout);
1428 packet_set_iv(MODE_IN, child_state.ivin);
1429 xfree(child_state.ivin);
1432 memcpy(&incoming_stream, &child_state.incoming,
1433 sizeof(incoming_stream));
1434 memcpy(&outgoing_stream, &child_state.outgoing,
1435 sizeof(outgoing_stream));
1437 /* Update with new address */
1438 if (options.compression)
1439 mm_init_compression(pmonitor->m_zlib);
1441 /* Network I/O buffers */
1442 /* XXX inefficient for large buffers, need: buffer_init_from_string */
1443 buffer_clear(&input);
1444 buffer_append(&input, child_state.input, child_state.ilen);
1445 memset(child_state.input, 0, child_state.ilen);
1446 xfree(child_state.input);
1448 buffer_clear(&output);
1449 buffer_append(&output, child_state.output, child_state.olen);
1450 memset(child_state.output, 0, child_state.olen);
1451 xfree(child_state.output);
1455 mm_get_kex(Buffer *m)
1461 kex = xmalloc(sizeof(*kex));
1462 memset(kex, 0, sizeof(*kex));
1463 kex->session_id = buffer_get_string(m, &kex->session_id_len);
1464 if ((session_id2 == NULL) ||
1465 (kex->session_id_len != session_id2_len) ||
1466 (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1467 fatal("mm_get_get: internal error: bad session id");
1468 kex->we_need = buffer_get_int(m);
1469 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1470 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1472 kex->hostkey_type = buffer_get_int(m);
1473 kex->kex_type = buffer_get_int(m);
1474 blob = buffer_get_string(m, &bloblen);
1475 buffer_init(&kex->my);
1476 buffer_append(&kex->my, blob, bloblen);
1478 blob = buffer_get_string(m, &bloblen);
1479 buffer_init(&kex->peer);
1480 buffer_append(&kex->peer, blob, bloblen);
1483 kex->flags = buffer_get_int(m);
1484 kex->client_version_string = buffer_get_string(m, NULL);
1485 kex->server_version_string = buffer_get_string(m, NULL);
1486 kex->load_host_key=&get_hostkey_by_type;
1487 kex->host_key_index=&get_hostkey_index;
1492 /* This function requries careful sanity checking */
1495 mm_get_keystate(struct monitor *pmonitor)
1499 u_int bloblen, plen;
1500 u_int32_t seqnr, packets;
1503 debug3("%s: Waiting for new keys", __func__);
1506 mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1508 child_state.ssh1protoflags = buffer_get_int(&m);
1509 child_state.ssh1cipher = buffer_get_int(&m);
1510 child_state.ssh1key = buffer_get_string(&m,
1511 &child_state.ssh1keylen);
1512 child_state.ivout = buffer_get_string(&m,
1513 &child_state.ivoutlen);
1514 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1517 /* Get the Kex for rekeying */
1518 *pmonitor->m_pkex = mm_get_kex(&m);
1521 blob = buffer_get_string(&m, &bloblen);
1522 current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1525 debug3("%s: Waiting for second key", __func__);
1526 blob = buffer_get_string(&m, &bloblen);
1527 current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1530 /* Now get sequence numbers for the packets */
1531 seqnr = buffer_get_int(&m);
1532 blocks = buffer_get_int64(&m);
1533 packets = buffer_get_int(&m);
1534 packet_set_state(MODE_OUT, seqnr, blocks, packets);
1535 seqnr = buffer_get_int(&m);
1536 blocks = buffer_get_int64(&m);
1537 packets = buffer_get_int(&m);
1538 packet_set_state(MODE_IN, seqnr, blocks, packets);
1541 /* Get the key context */
1542 child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1543 child_state.keyin = buffer_get_string(&m, &child_state.keyinlen);
1545 debug3("%s: Getting compression state", __func__);
1546 /* Get compression state */
1547 p = buffer_get_string(&m, &plen);
1548 if (plen != sizeof(child_state.outgoing))
1549 fatal("%s: bad request size", __func__);
1550 memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1553 p = buffer_get_string(&m, &plen);
1554 if (plen != sizeof(child_state.incoming))
1555 fatal("%s: bad request size", __func__);
1556 memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1559 /* Network I/O buffers */
1560 debug3("%s: Getting Network I/O buffers", __func__);
1561 child_state.input = buffer_get_string(&m, &child_state.ilen);
1562 child_state.output = buffer_get_string(&m, &child_state.olen);
1568 /* Allocation functions for zlib */
1570 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1572 size_t len = (size_t) size * ncount;
1575 if (len == 0 || ncount > SIZE_T_MAX / size)
1576 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1578 address = mm_malloc(mm, len);
1584 mm_zfree(struct mm_master *mm, void *address)
1586 mm_free(mm, address);
1590 mm_init_compression(struct mm_master *mm)
1592 outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1593 outgoing_stream.zfree = (free_func)mm_zfree;
1594 outgoing_stream.opaque = mm;
1596 incoming_stream.zalloc = (alloc_func)mm_zalloc;
1597 incoming_stream.zfree = (free_func)mm_zfree;
1598 incoming_stream.opaque = mm;
1603 #define FD_CLOSEONEXEC(x) do { \
1604 if (fcntl(x, F_SETFD, 1) == -1) \
1605 fatal("fcntl(%d, F_SETFD)", x); \
1609 monitor_socketpair(int *pair)
1611 #ifdef HAVE_SOCKETPAIR
1612 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1613 fatal("%s: socketpair", __func__);
1615 fatal("%s: UsePrivilegeSeparation=yes not supported",
1618 FD_CLOSEONEXEC(pair[0]);
1619 FD_CLOSEONEXEC(pair[1]);
1622 #define MM_MEMSIZE 65536
1627 struct monitor *mon;
1630 mon = xmalloc(sizeof(*mon));
1632 monitor_socketpair(pair);
1634 mon->m_recvfd = pair[0];
1635 mon->m_sendfd = pair[1];
1637 /* Used to share zlib space across processes */
1638 if (options.compression) {
1639 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1640 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1642 /* Compression needs to share state across borders */
1643 mm_init_compression(mon->m_zlib);
1650 monitor_reinit(struct monitor *mon)
1654 monitor_socketpair(pair);
1656 mon->m_recvfd = pair[0];
1657 mon->m_sendfd = pair[1];