1 /* $OpenBSD: sshconnect2.c,v 1.351 2021/07/23 05:24:02 djm Exp $ */
3 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 * Copyright (c) 2008 Damien Miller. All rights reserved.
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.
29 #include <sys/types.h>
30 #include <sys/socket.h>
44 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
48 #include "openbsd-compat/sys-queue.h"
59 #include "myproposal.h"
60 #include "sshconnect.h"
71 #include "pathnames.h"
84 extern char *client_version_string;
85 extern char *server_version_string;
86 extern Options options;
92 static char *xxx_host;
93 static struct sockaddr *xxx_hostaddr;
94 static const struct ssh_conn_info *xxx_conn_info;
97 verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
99 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey,
100 xxx_conn_info) == -1)
101 fatal("Host key verification failed.");
105 /* Returns the first item from a comma-separated algorithm list */
107 first_alg(const char *algs)
112 if ((cp = strchr(ret, ',')) != NULL)
118 order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port,
119 const struct ssh_conn_info *cinfo)
121 char *oavail = NULL, *avail = NULL, *first = NULL, *last = NULL;
122 char *alg = NULL, *hostname = NULL, *ret = NULL, *best = NULL;
124 struct hostkeys *hostkeys = NULL;
128 /* Find all hostkeys for this hostname */
129 get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
130 hostkeys = init_hostkeys();
131 for (i = 0; i < options.num_user_hostfiles; i++)
132 load_hostkeys(hostkeys, hostname, options.user_hostfiles[i], 0);
133 for (i = 0; i < options.num_system_hostfiles; i++) {
134 load_hostkeys(hostkeys, hostname,
135 options.system_hostfiles[i], 0);
137 if (options.known_hosts_command != NULL) {
138 load_hostkeys_command(hostkeys, options.known_hosts_command,
139 "ORDER", cinfo, NULL, host);
142 * If a plain public key exists that matches the type of the best
143 * preference HostkeyAlgorithms, then use the whole list as is.
144 * Note that we ignore whether the best preference algorithm is a
145 * certificate type, as sshconnect.c will downgrade certs to
146 * plain keys if necessary.
148 best = first_alg(options.hostkeyalgorithms);
149 if (lookup_key_in_hostkeys_by_type(hostkeys,
150 sshkey_type_plain(sshkey_type_from_name(best)),
151 sshkey_ecdsa_nid_from_name(best), NULL)) {
152 debug3_f("have matching best-preference key type %s, "
153 "using HostkeyAlgorithms verbatim", best);
154 ret = xstrdup(options.hostkeyalgorithms);
159 * Otherwise, prefer the host key algorithms that match known keys
160 * while keeping the ordering of HostkeyAlgorithms as much as possible.
162 oavail = avail = xstrdup(options.hostkeyalgorithms);
163 maxlen = strlen(avail) + 1;
164 first = xmalloc(maxlen);
165 last = xmalloc(maxlen);
166 *first = *last = '\0';
168 #define ALG_APPEND(to, from) \
171 strlcat(to, ",", maxlen); \
172 strlcat(to, from, maxlen); \
175 while ((alg = strsep(&avail, ",")) && *alg != '\0') {
176 if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
177 fatal_f("unknown alg %s", alg);
179 * If we have a @cert-authority marker in known_hosts then
180 * prefer all certificate algorithms.
182 if (sshkey_type_is_cert(ktype) &&
183 lookup_marker_in_hostkeys(hostkeys, MRK_CA)) {
184 ALG_APPEND(first, alg);
187 /* If the key appears in known_hosts then prefer it */
188 if (lookup_key_in_hostkeys_by_type(hostkeys,
189 sshkey_type_plain(ktype),
190 sshkey_ecdsa_nid_from_name(alg), NULL)) {
191 ALG_APPEND(first, alg);
194 /* Otherwise, put it last */
195 ALG_APPEND(last, alg);
198 xasprintf(&ret, "%s%s%s", first,
199 (*first == '\0' || *last == '\0') ? "" : ",", last);
201 debug3_f("prefer hostkeyalgs: %s", first);
203 debug3_f("no algorithms matched; accept original");
210 free_hostkeys(hostkeys);
216 ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port,
217 const struct ssh_conn_info *cinfo)
219 char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
221 int r, use_known_hosts_order = 0;
224 xxx_hostaddr = hostaddr;
225 xxx_conn_info = cinfo;
228 * If the user has not specified HostkeyAlgorithms, or has only
229 * appended or removed algorithms from that list then prefer algorithms
230 * that are in the list that are supported by known_hosts keys.
232 if (options.hostkeyalgorithms == NULL ||
233 options.hostkeyalgorithms[0] == '-' ||
234 options.hostkeyalgorithms[0] == '+')
235 use_known_hosts_order = 1;
237 /* Expand or fill in HostkeyAlgorithms */
238 all_key = sshkey_alg_list(0, 0, 1, ',');
239 if ((r = kex_assemble_names(&options.hostkeyalgorithms,
240 kex_default_pk_alg(), all_key)) != 0)
241 fatal_fr(r, "kex_assemble_namelist");
244 if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
245 fatal_f("kex_names_cat");
246 myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(ssh, s);
247 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
248 compat_cipher_proposal(ssh, options.ciphers);
249 myproposal[PROPOSAL_ENC_ALGS_STOC] =
250 compat_cipher_proposal(ssh, options.ciphers);
251 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
252 myproposal[PROPOSAL_COMP_ALGS_STOC] =
253 (char *)compression_alg_list(options.compression);
254 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
255 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
256 if (use_known_hosts_order) {
257 /* Query known_hosts and prefer algorithms that appear there */
258 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
259 compat_pkalg_proposal(ssh,
260 order_hostkeyalgs(host, hostaddr, port, cinfo));
262 /* Use specified HostkeyAlgorithms exactly */
263 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
264 compat_pkalg_proposal(ssh, options.hostkeyalgorithms);
267 if (options.rekey_limit || options.rekey_interval)
268 ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
269 options.rekey_interval);
271 /* start key exchange */
272 if ((r = kex_setup(ssh, myproposal)) != 0)
273 fatal_r(r, "kex_setup");
275 ssh->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_client;
276 ssh->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_client;
277 ssh->kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_client;
278 ssh->kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_client;
279 ssh->kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_client;
280 ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
281 ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
282 # ifdef OPENSSL_HAS_ECC
283 ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client;
286 ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client;
287 ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client;
288 ssh->kex->verify_host_key=&verify_host_key_callback;
290 ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &ssh->kex->done);
292 /* remove ext-info from the KEX proposals for rekeying */
293 myproposal[PROPOSAL_KEX_ALGS] =
294 compat_kex_proposal(ssh, options.kex_algorithms);
295 if ((r = kex_prop2buf(ssh->kex->my, myproposal)) != 0)
296 fatal_r(r, "kex_prop2buf");
299 /* send 1st encrypted/maced/compressed message */
300 if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
301 (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
302 (r = sshpkt_send(ssh)) != 0 ||
303 (r = ssh_packet_write_wait(ssh)) != 0)
304 fatal_fr(r, "send packet");
312 typedef struct cauthctxt Authctxt;
313 typedef struct cauthmethod Authmethod;
314 typedef struct identity Identity;
315 typedef struct idlist Idlist;
318 TAILQ_ENTRY(identity) next;
319 int agent_fd; /* >=0 if agent supports key */
320 struct sshkey *key; /* public/private key */
321 char *filename; /* comment for agent-only keys */
323 int isprivate; /* key points to the private key */
326 TAILQ_HEAD(idlist, identity);
329 const char *server_user;
330 const char *local_user;
333 struct cauthmethod *method;
334 sig_atomic_t success;
338 gss_OID_set gss_supported_mechs;
345 Sensitive *sensitive;
346 char *oktypes, *ktypes;
347 const char *active_ktype;
348 /* kbd-interactive */
358 char *name; /* string to compare against server's list */
359 int (*userauth)(struct ssh *ssh);
360 void (*cleanup)(struct ssh *ssh);
361 int *enabled; /* flag in option struct that enables method */
362 int *batch_flag; /* flag in option struct that disables method */
365 static int input_userauth_service_accept(int, u_int32_t, struct ssh *);
366 static int input_userauth_ext_info(int, u_int32_t, struct ssh *);
367 static int input_userauth_success(int, u_int32_t, struct ssh *);
368 static int input_userauth_failure(int, u_int32_t, struct ssh *);
369 static int input_userauth_banner(int, u_int32_t, struct ssh *);
370 static int input_userauth_error(int, u_int32_t, struct ssh *);
371 static int input_userauth_info_req(int, u_int32_t, struct ssh *);
372 static int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
373 static int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
375 static int userauth_none(struct ssh *);
376 static int userauth_pubkey(struct ssh *);
377 static int userauth_passwd(struct ssh *);
378 static int userauth_kbdint(struct ssh *);
379 static int userauth_hostbased(struct ssh *);
382 static int userauth_gssapi(struct ssh *);
383 static void userauth_gssapi_cleanup(struct ssh *);
384 static int input_gssapi_response(int type, u_int32_t, struct ssh *);
385 static int input_gssapi_token(int type, u_int32_t, struct ssh *);
386 static int input_gssapi_error(int, u_int32_t, struct ssh *);
387 static int input_gssapi_errtok(int, u_int32_t, struct ssh *);
390 void userauth(struct ssh *, char *);
392 static void pubkey_cleanup(struct ssh *);
393 static int sign_and_send_pubkey(struct ssh *ssh, Identity *);
394 static void pubkey_prepare(Authctxt *);
395 static void pubkey_reset(Authctxt *);
396 static struct sshkey *load_identity_file(Identity *);
398 static Authmethod *authmethod_get(char *authlist);
399 static Authmethod *authmethod_lookup(const char *name);
400 static char *authmethods_get(void);
402 Authmethod authmethods[] = {
406 userauth_gssapi_cleanup,
407 &options.gss_authentication,
413 &options.hostbased_authentication,
418 &options.pubkey_authentication,
420 {"keyboard-interactive",
423 &options.kbd_interactive_authentication,
424 &options.batch_mode},
428 &options.password_authentication,
429 &options.batch_mode},
435 {NULL, NULL, NULL, NULL, NULL}
439 ssh_userauth2(struct ssh *ssh, const char *local_user,
440 const char *server_user, char *host, Sensitive *sensitive)
445 if (options.preferred_authentications == NULL)
446 options.preferred_authentications = authmethods_get();
448 /* setup authentication context */
449 memset(&authctxt, 0, sizeof(authctxt));
450 authctxt.server_user = server_user;
451 authctxt.local_user = local_user;
452 authctxt.host = host;
453 authctxt.service = "ssh-connection"; /* service name */
454 authctxt.success = 0;
455 authctxt.method = authmethod_lookup("none");
456 authctxt.authlist = NULL;
457 authctxt.methoddata = NULL;
458 authctxt.sensitive = sensitive;
459 authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
460 authctxt.info_req_seen = 0;
461 authctxt.attempt_kbdint = 0;
462 authctxt.attempt_passwd = 0;
464 authctxt.gss_supported_mechs = NULL;
465 authctxt.mech_tried = 0;
467 authctxt.agent_fd = -1;
468 pubkey_prepare(&authctxt);
469 if (authctxt.method == NULL) {
470 fatal_f("internal error: cannot send userauth none request");
473 if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
474 (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
475 (r = sshpkt_send(ssh)) != 0)
476 fatal_fr(r, "send packet");
478 ssh->authctxt = &authctxt;
479 ssh_dispatch_init(ssh, &input_userauth_error);
480 ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
481 ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
482 ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
484 ssh->authctxt = NULL;
486 ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
488 if (!authctxt.success)
489 fatal("Authentication failed.");
490 if (ssh_packet_connection_is_on_socket(ssh)) {
491 verbose("Authenticated to %s ([%s]:%d) using \"%s\".", host,
492 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
493 authctxt.method->name);
495 verbose("Authenticated to %s (via proxy) using \"%s\".", host,
496 authctxt.method->name);
502 input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
506 if (ssh_packet_remaining(ssh) > 0) {
509 if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
511 debug2("service_accept: %s", reply);
514 debug2("buggy server: service_accept w/o service");
516 if ((r = sshpkt_get_end(ssh)) != 0)
518 debug("SSH2_MSG_SERVICE_ACCEPT received");
520 /* initial userauth request */
523 ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
524 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
525 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
526 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
534 input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
536 return kex_input_ext_info(type, seqnr, ssh);
540 userauth(struct ssh *ssh, char *authlist)
542 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
544 if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
545 authctxt->method->cleanup(ssh);
547 free(authctxt->methoddata);
548 authctxt->methoddata = NULL;
549 if (authlist == NULL) {
550 authlist = authctxt->authlist;
552 free(authctxt->authlist);
553 authctxt->authlist = authlist;
556 Authmethod *method = authmethod_get(authlist);
558 fatal("%s@%s: Permission denied (%s).",
559 authctxt->server_user, authctxt->host, authlist);
560 authctxt->method = method;
562 /* reset the per method handler */
563 ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
564 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
566 /* and try new method */
567 if (method->userauth(ssh) != 0) {
568 debug2("we sent a %s packet, wait for reply", method->name);
571 debug2("we did not send a packet, disable method");
572 method->enabled = NULL;
579 input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
581 fatal_f("bad message during authentication: type %d", type);
587 input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
593 debug3_f("entering");
594 if ((r = sshpkt_get_cstring(ssh, &msg, &len)) != 0 ||
595 (r = sshpkt_get_cstring(ssh, NULL, NULL)) != 0)
597 if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
598 fmprintf(stderr, "%s", msg);
607 input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
609 Authctxt *authctxt = ssh->authctxt;
611 if (authctxt == NULL)
612 fatal_f("no authentication context");
613 free(authctxt->authlist);
614 authctxt->authlist = NULL;
615 if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
616 authctxt->method->cleanup(ssh);
617 free(authctxt->methoddata);
618 authctxt->methoddata = NULL;
619 authctxt->success = 1; /* break out */
625 input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
627 Authctxt *authctxt = ssh->authctxt;
629 if (authctxt == NULL)
630 fatal_f("no authentication context");
632 fatal("Unexpected authentication success during %s.",
633 authctxt->method->name);
640 input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
642 Authctxt *authctxt = ssh->authctxt;
643 char *authlist = NULL;
646 if (authctxt == NULL)
647 fatal("input_userauth_failure: no authentication context");
649 if (sshpkt_get_cstring(ssh, &authlist, NULL) != 0 ||
650 sshpkt_get_u8(ssh, &partial) != 0 ||
651 sshpkt_get_end(ssh) != 0)
655 verbose("Authenticated using \"%s\" with partial success.",
656 authctxt->method->name);
658 pubkey_reset(authctxt);
660 debug("Authentications that can continue: %s", authlist);
662 userauth(ssh, authlist);
670 * Format an identity for logging including filename, key type, fingerprint
671 * and location (agent, etc.). Caller must free.
674 format_identity(Identity *id)
676 char *fp = NULL, *ret = NULL;
677 const char *note = "";
679 if (id->key != NULL) {
680 fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
684 if ((id->key->flags & SSHKEY_FLAG_EXT) != 0)
686 else if (sshkey_is_sk(id->key))
687 note = " authenticator";
689 xasprintf(&ret, "%s %s%s%s%s%s%s",
691 id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
693 id->userprovided ? " explicit" : "", note,
694 id->agent_fd != -1 ? " agent" : "");
701 input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
703 Authctxt *authctxt = ssh->authctxt;
704 struct sshkey *key = NULL;
706 int pktype, found = 0, sent = 0;
708 char *pkalg = NULL, *fp = NULL, *ident = NULL;
709 u_char *pkblob = NULL;
712 if (authctxt == NULL)
713 fatal("input_userauth_pk_ok: no authentication context");
715 if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
716 (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
717 (r = sshpkt_get_end(ssh)) != 0)
720 if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
721 debug_f("server sent unknown pkalg %s", pkalg);
724 if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
725 debug_r(r, "no key from blob. pkalg %s", pkalg);
728 if (key->type != pktype) {
729 error("input_userauth_pk_ok: type mismatch "
730 "for decoded key (received %d, expected %d)",
736 * search keys in the reverse order, because last candidate has been
737 * moved to the end of the queue. this also avoids confusion by
740 TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
741 if (sshkey_equal(key, id->key)) {
746 if (!found || id == NULL) {
747 fp = sshkey_fingerprint(key, options.fingerprint_hash,
749 error_f("server replied with unknown key: %s %s",
750 sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
753 ident = format_identity(id);
754 debug("Server accepts key: %s", ident);
755 sent = sign_and_send_pubkey(ssh, id);
764 /* try another method if we did not send a packet */
765 if (r == 0 && sent == 0)
772 userauth_gssapi(struct ssh *ssh)
774 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
775 Gssctxt *gssctxt = NULL;
780 /* Try one GSSAPI method at a time, rather than sending them all at
783 if (authctxt->gss_supported_mechs == NULL)
784 gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
786 /* Check to see whether the mechanism is usable before we offer it */
787 while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
789 mech = &authctxt->gss_supported_mechs->
790 elements[authctxt->mech_tried];
791 /* My DER encoding requires length<128 */
792 if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
793 mech, authctxt->host)) {
794 ok = 1; /* Mechanism works */
796 authctxt->mech_tried++;
800 if (!ok || mech == NULL)
803 authctxt->methoddata=(void *)gssctxt;
805 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
806 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
807 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
808 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
809 (r = sshpkt_put_u32(ssh, 1)) != 0 ||
810 (r = sshpkt_put_u32(ssh, (mech->length) + 2)) != 0 ||
811 (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
812 (r = sshpkt_put_u8(ssh, mech->length)) != 0 ||
813 (r = sshpkt_put(ssh, mech->elements, mech->length)) != 0 ||
814 (r = sshpkt_send(ssh)) != 0)
815 fatal_fr(r, "send packet");
817 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
818 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
819 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
820 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
822 authctxt->mech_tried++; /* Move along to next candidate */
828 userauth_gssapi_cleanup(struct ssh *ssh)
830 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
831 Gssctxt *gssctxt = (Gssctxt *)authctxt->methoddata;
833 ssh_gssapi_delete_ctx(&gssctxt);
834 authctxt->methoddata = NULL;
836 free(authctxt->gss_supported_mechs);
837 authctxt->gss_supported_mechs = NULL;
841 process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
843 Authctxt *authctxt = ssh->authctxt;
844 Gssctxt *gssctxt = authctxt->methoddata;
845 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
846 gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
847 gss_buffer_desc gssbuf;
848 OM_uint32 status, ms, flags;
851 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
852 recv_tok, &send_tok, &flags);
854 if (send_tok.length > 0) {
855 u_char type = GSS_ERROR(status) ?
856 SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
857 SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
859 if ((r = sshpkt_start(ssh, type)) != 0 ||
860 (r = sshpkt_put_string(ssh, send_tok.value,
861 send_tok.length)) != 0 ||
862 (r = sshpkt_send(ssh)) != 0)
863 fatal_fr(r, "send %u packet", type);
865 gss_release_buffer(&ms, &send_tok);
868 if (status == GSS_S_COMPLETE) {
869 /* send either complete or MIC, depending on mechanism */
870 if (!(flags & GSS_C_INTEG_FLAG)) {
871 if ((r = sshpkt_start(ssh,
872 SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
873 (r = sshpkt_send(ssh)) != 0)
874 fatal_fr(r, "send completion");
878 if ((b = sshbuf_new()) == NULL)
879 fatal_f("sshbuf_new failed");
880 ssh_gssapi_buildmic(b, authctxt->server_user,
881 authctxt->service, "gssapi-with-mic",
882 ssh->kex->session_id);
884 if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
885 fatal_f("sshbuf_mutable_ptr failed");
886 gssbuf.length = sshbuf_len(b);
888 status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
890 if (!GSS_ERROR(status)) {
891 if ((r = sshpkt_start(ssh,
892 SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
893 (r = sshpkt_put_string(ssh, mic.value,
895 (r = sshpkt_send(ssh)) != 0)
896 fatal_fr(r, "send MIC");
900 gss_release_buffer(&ms, &mic);
909 input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
911 Authctxt *authctxt = ssh->authctxt;
917 if (authctxt == NULL)
918 fatal("input_gssapi_response: no authentication context");
919 gssctxt = authctxt->methoddata;
922 if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
926 oidv[0] != SSH_GSS_OIDTYPE ||
927 oidv[1] != oidlen - 2) {
928 debug("Badly encoded mechanism OID received");
933 if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
934 fatal("Server returned different OID than expected");
936 if ((r = sshpkt_get_end(ssh)) != 0)
939 if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
940 /* Start again with next method on list */
941 debug("Trying to start again");
954 input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
956 Authctxt *authctxt = ssh->authctxt;
957 gss_buffer_desc recv_tok;
963 if (authctxt == NULL)
964 fatal("input_gssapi_response: no authentication context");
966 if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
967 (r = sshpkt_get_end(ssh)) != 0)
971 recv_tok.length = len;
972 status = process_gssapi_token(ssh, &recv_tok);
974 /* Start again with the next method in the list */
975 if (GSS_ERROR(status)) {
987 input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
989 Authctxt *authctxt = ssh->authctxt;
991 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
992 gss_buffer_desc recv_tok;
998 if (authctxt == NULL)
999 fatal("input_gssapi_response: no authentication context");
1000 gssctxt = authctxt->methoddata;
1002 if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
1003 (r = sshpkt_get_end(ssh)) != 0) {
1008 /* Stick it into GSSAPI and see what it says */
1010 recv_tok.length = len;
1011 (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1012 &recv_tok, &send_tok, NULL);
1014 gss_release_buffer(&ms, &send_tok);
1016 /* Server will be returning a failed packet after this one */
1022 input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1028 if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
1029 (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
1030 (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
1031 (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1033 r = sshpkt_get_end(ssh);
1034 debug("Server GSSAPI Error:\n%s", msg);
1043 userauth_none(struct ssh *ssh)
1045 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1048 /* initial userauth request */
1049 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1050 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1051 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1052 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1053 (r = sshpkt_send(ssh)) != 0)
1054 fatal_fr(r, "send packet");
1059 userauth_passwd(struct ssh *ssh)
1061 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1062 char *password, *prompt = NULL;
1063 const char *host = options.host_key_alias ? options.host_key_alias :
1067 if (authctxt->attempt_passwd++ >= options.number_of_password_prompts)
1070 if (authctxt->attempt_passwd != 1)
1071 error("Permission denied, please try again.");
1073 xasprintf(&prompt, "%s@%s's password: ", authctxt->server_user, host);
1074 password = read_passphrase(prompt, 0);
1075 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1076 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1077 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1078 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1079 (r = sshpkt_put_u8(ssh, 0)) != 0 ||
1080 (r = sshpkt_put_cstring(ssh, password)) != 0 ||
1081 (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1082 (r = sshpkt_send(ssh)) != 0)
1083 fatal_fr(r, "send packet");
1086 if (password != NULL)
1087 freezero(password, strlen(password));
1089 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1090 &input_userauth_passwd_changereq);
1096 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
1100 input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1102 Authctxt *authctxt = ssh->authctxt;
1103 char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1108 debug2("input_userauth_passwd_changereq");
1110 if (authctxt == NULL)
1111 fatal("input_userauth_passwd_changereq: "
1112 "no authentication context");
1113 host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1115 if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
1116 (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1118 if (strlen(info) > 0)
1120 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1121 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1122 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1123 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1124 (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
1127 snprintf(prompt, sizeof(prompt),
1128 "Enter %.30s@%.128s's old password: ",
1129 authctxt->server_user, host);
1130 password = read_passphrase(prompt, 0);
1131 if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1134 freezero(password, strlen(password));
1136 while (password == NULL) {
1137 snprintf(prompt, sizeof(prompt),
1138 "Enter %.30s@%.128s's new password: ",
1139 authctxt->server_user, host);
1140 password = read_passphrase(prompt, RP_ALLOW_EOF);
1141 if (password == NULL) {
1146 snprintf(prompt, sizeof(prompt),
1147 "Retype %.30s@%.128s's new password: ",
1148 authctxt->server_user, host);
1149 retype = read_passphrase(prompt, 0);
1150 if (strcmp(password, retype) != 0) {
1151 freezero(password, strlen(password));
1152 logit("Mismatch; try again, EOF to quit.");
1155 freezero(retype, strlen(retype));
1157 if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1158 (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1159 (r = sshpkt_send(ssh)) != 0)
1162 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1163 &input_userauth_passwd_changereq);
1167 freezero(password, strlen(password));
1174 * Select an algorithm for publickey signatures.
1175 * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1177 * Call with ssh==NULL to ignore server-sig-algs extension list and
1178 * only attempt with the key's base signature type.
1181 key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1183 char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1184 const char *server_sig_algs;
1187 * The signature algorithm will only differ from the key algorithm
1188 * for RSA keys/certs and when the server advertises support for
1189 * newer (SHA2) algorithms.
1191 if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1192 (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
1193 (key->type == KEY_RSA_CERT && (ssh->compat & SSH_BUG_SIGTYPE))) {
1194 /* Filter base key signature alg against our configuration */
1195 return match_list(sshkey_ssh_name(key),
1196 options.pubkey_accepted_algos, NULL);
1200 * Workaround OpenSSH 7.4 bug: this version supports RSA/SHA-2 but
1201 * fails to advertise it via SSH2_MSG_EXT_INFO.
1203 server_sig_algs = ssh->kex->server_sig_algs;
1204 if (key->type == KEY_RSA && (ssh->compat & SSH_BUG_SIGTYPE74))
1205 server_sig_algs = "rsa-sha2-256,rsa-sha2-512";
1208 * For RSA keys/certs, since these might have a different sig type:
1209 * find the first entry in PubkeyAcceptedAlgorithms of the right type
1210 * that also appears in the supported signature algorithms list from
1213 oallowed = allowed = xstrdup(options.pubkey_accepted_algos);
1214 while ((cp = strsep(&allowed, ",")) != NULL) {
1215 if (sshkey_type_from_name(cp) != key->type)
1217 tmp = match_list(sshkey_sigalg_by_name(cp),
1218 server_sig_algs, NULL);
1230 identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1231 const u_char *data, size_t datalen, u_int compat, const char *alg)
1233 struct sshkey *sign_key = NULL, *prv = NULL;
1234 int retried = 0, r = SSH_ERR_INTERNAL_ERROR;
1235 struct notifier_ctx *notifier = NULL;
1236 char *fp = NULL, *pin = NULL, *prompt = NULL;
1241 /* The agent supports this key. */
1242 if (id->key != NULL && id->agent_fd != -1) {
1243 return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1244 data, datalen, alg, compat);
1248 * We have already loaded the private key or the private key is
1249 * stored in external hardware.
1251 if (id->key != NULL &&
1252 (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1255 /* Load the private key from the file. */
1256 if ((prv = load_identity_file(id)) == NULL)
1257 return SSH_ERR_KEY_NOT_FOUND;
1258 if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1259 error_f("private key %s contents do not match public",
1261 r = SSH_ERR_KEY_NOT_FOUND;
1265 if (sshkey_is_sk(sign_key)) {
1266 if ((sign_key->sk_flags &
1267 SSH_SK_USER_VERIFICATION_REQD)) {
1269 xasprintf(&prompt, "Enter PIN for %s key %s: ",
1270 sshkey_type(sign_key), id->filename);
1271 pin = read_passphrase(prompt, 0);
1273 if ((sign_key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
1274 /* XXX should batch mode just skip these? */
1275 if ((fp = sshkey_fingerprint(sign_key,
1276 options.fingerprint_hash,
1277 SSH_FP_DEFAULT)) == NULL)
1278 fatal_f("fingerprint failed");
1279 notifier = notify_start(options.batch_mode,
1280 "Confirm user presence for key %s %s",
1281 sshkey_type(sign_key), fp);
1286 if ((r = sshkey_sign(sign_key, sigp, lenp, data, datalen,
1287 alg, options.sk_provider, pin, compat)) != 0) {
1288 debug_fr(r, "sshkey_sign");
1289 if (pin == NULL && !retried && sshkey_is_sk(sign_key) &&
1290 r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
1291 notify_complete(notifier, NULL);
1300 * PKCS#11 tokens may not support all signature algorithms,
1301 * so check what we get back.
1303 if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0) {
1304 debug_fr(r, "sshkey_check_sigtype");
1312 freezero(pin, strlen(pin));
1313 notify_complete(notifier, r == 0 ? "User presence confirmed" : NULL);
1319 id_filename_matches(Identity *id, Identity *private_id)
1321 const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1322 size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1325 if (strcmp(id->filename, private_id->filename) == 0)
1327 for (i = 0; suffixes[i]; i++) {
1328 slen = strlen(suffixes[i]);
1329 if (len > slen && plen == len - slen &&
1330 strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1331 memcmp(id->filename, private_id->filename, plen) == 0)
1338 sign_and_send_pubkey(struct ssh *ssh, Identity *id)
1340 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1341 struct sshbuf *b = NULL;
1342 Identity *private_id, *sign_id = NULL;
1343 u_char *signature = NULL;
1344 size_t slen = 0, skip = 0;
1345 int r, fallback_sigtype, sent = 0;
1346 char *alg = NULL, *fp = NULL;
1347 const char *loc = "";
1349 if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1350 SSH_FP_DEFAULT)) == NULL)
1353 debug3_f("%s %s", sshkey_type(id->key), fp);
1356 * If the key is an certificate, try to find a matching private key
1357 * and use it to complete the signature.
1358 * If no such private key exists, fall back to trying the certificate
1359 * key itself in case it has a private half already loaded.
1360 * This will try to set sign_id to the private key that will perform
1363 if (sshkey_is_cert(id->key)) {
1364 TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1365 if (sshkey_equal_public(id->key, private_id->key) &&
1366 id->key->type != private_id->key->type) {
1367 sign_id = private_id;
1372 * Exact key matches are preferred, but also allow
1373 * filename matches for non-PKCS#11/agent keys that
1374 * didn't load public keys. This supports the case
1375 * of keeping just a private key file and public
1376 * certificate on disk.
1378 if (sign_id == NULL &&
1379 !id->isprivate && id->agent_fd == -1 &&
1380 (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1381 TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1382 if (private_id->key == NULL &&
1383 id_filename_matches(id, private_id)) {
1384 sign_id = private_id;
1389 if (sign_id != NULL) {
1390 debug2_f("using private key \"%s\"%s for "
1391 "certificate", sign_id->filename,
1392 sign_id->agent_fd != -1 ? " from agent" : "");
1394 debug_f("no separate private key for certificate "
1395 "\"%s\"", id->filename);
1400 * If the above didn't select another identity to do the signing
1401 * then default to the one we started with.
1403 if (sign_id == NULL)
1406 /* assemble and sign data */
1407 for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1411 if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1412 id->key)) == NULL) {
1413 error_f("no mutual signature supported");
1416 debug3_f("signing using %s %s", alg, fp);
1419 if ((b = sshbuf_new()) == NULL)
1420 fatal_f("sshbuf_new failed");
1421 if (ssh->compat & SSH_OLD_SESSIONID) {
1422 if ((r = sshbuf_putb(b, ssh->kex->session_id)) != 0)
1423 fatal_fr(r, "sshbuf_putb");
1425 if ((r = sshbuf_put_stringb(b,
1426 ssh->kex->session_id)) != 0)
1427 fatal_fr(r, "sshbuf_put_stringb");
1429 skip = sshbuf_len(b);
1430 if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1431 (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1432 (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1433 (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1434 (r = sshbuf_put_u8(b, 1)) != 0 ||
1435 (r = sshbuf_put_cstring(b, alg)) != 0 ||
1436 (r = sshkey_puts(id->key, b)) != 0) {
1437 fatal_fr(r, "assemble signed data");
1440 /* generate signature */
1441 r = identity_sign(sign_id, &signature, &slen,
1442 sshbuf_ptr(b), sshbuf_len(b), ssh->compat, alg);
1445 else if (r == SSH_ERR_KEY_NOT_FOUND)
1446 goto out; /* soft failure */
1447 else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1448 !fallback_sigtype) {
1449 if (sign_id->agent_fd != -1)
1451 else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1453 logit("%skey %s %s returned incorrect signature type",
1454 loc, sshkey_type(id->key), fp);
1457 error_fr(r, "signing failed for %s \"%s\"%s",
1458 sshkey_type(sign_id->key), sign_id->filename,
1459 id->agent_fd != -1 ? " from agent" : "");
1462 if (slen == 0 || signature == NULL) /* shouldn't happen */
1463 fatal_f("no signature");
1465 /* append signature */
1466 if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1467 fatal_fr(r, "append signature");
1470 sshbuf_dump(b, stderr);
1472 /* skip session id and packet type */
1473 if ((r = sshbuf_consume(b, skip + 1)) != 0)
1474 fatal_fr(r, "consume");
1476 /* put remaining data from buffer into packet */
1477 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1478 (r = sshpkt_putb(ssh, b)) != 0 ||
1479 (r = sshpkt_send(ssh)) != 0)
1480 fatal_fr(r, "enqueue request");
1489 freezero(signature, slen);
1494 send_pubkey_test(struct ssh *ssh, Identity *id)
1496 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1497 u_char *blob = NULL;
1503 if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1504 debug_f("no mutual signature algorithm");
1508 if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1509 /* we cannot handle this key */
1510 debug3_f("cannot handle key");
1513 /* register callback for USERAUTH_PK_OK message */
1514 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1516 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1517 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1518 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1519 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1520 (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1521 (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1522 (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1523 (r = sshpkt_send(ssh)) != 0)
1524 fatal_fr(r, "send packet");
1533 static struct sshkey *
1534 load_identity_file(Identity *id)
1536 struct sshkey *private = NULL;
1537 char prompt[300], *passphrase, *comment;
1541 if (stat(id->filename, &st) == -1) {
1542 do_log2(id->userprovided ?
1543 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_DEBUG3,
1544 "no such identity: %s: %s", id->filename, strerror(errno));
1547 snprintf(prompt, sizeof prompt,
1548 "Enter passphrase for key '%.100s': ", id->filename);
1549 for (i = 0; i <= options.number_of_password_prompts; i++) {
1553 passphrase = read_passphrase(prompt, 0);
1554 if (*passphrase == '\0') {
1555 debug2("no passphrase given, try next key");
1560 switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1561 passphrase, &private, &comment))) {
1564 case SSH_ERR_KEY_WRONG_PASSPHRASE:
1565 if (options.batch_mode) {
1570 debug2("bad passphrase given, try again...");
1572 case SSH_ERR_SYSTEM_ERROR:
1573 if (errno == ENOENT) {
1574 debug2_r(r, "Load key \"%s\"", id->filename);
1580 error_r(r, "Load key \"%s\"", id->filename);
1584 if (private != NULL && sshkey_is_sk(private) &&
1585 options.sk_provider == NULL) {
1586 debug("key \"%s\" is an authenticator-hosted key, "
1587 "but no provider specified", id->filename);
1588 sshkey_free(private);
1592 if (!quit && private != NULL && id->agent_fd == -1 &&
1593 !(id->key && id->isprivate))
1594 maybe_add_key_to_agent(id->filename, private, comment,
1597 freezero(passphrase, strlen(passphrase));
1599 if (private != NULL || quit)
1606 key_type_allowed_by_config(struct sshkey *key)
1608 if (match_pattern_list(sshkey_ssh_name(key),
1609 options.pubkey_accepted_algos, 0) == 1)
1612 /* RSA keys/certs might be allowed by alternate signature types */
1613 switch (key->type) {
1615 if (match_pattern_list("rsa-sha2-512",
1616 options.pubkey_accepted_algos, 0) == 1)
1618 if (match_pattern_list("rsa-sha2-256",
1619 options.pubkey_accepted_algos, 0) == 1)
1623 if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1624 options.pubkey_accepted_algos, 0) == 1)
1626 if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1627 options.pubkey_accepted_algos, 0) == 1)
1636 * try keys in the following order:
1637 * 1. certificates listed in the config file
1638 * 2. other input certificates
1639 * 3. agent keys that are found in the config file
1640 * 4. other agent keys
1641 * 5. keys that are only listed in the config file
1644 pubkey_prepare(Authctxt *authctxt)
1646 struct identity *id, *id2, *tmp;
1647 struct idlist agent, files, *preferred;
1649 int agent_fd = -1, i, r, found;
1651 struct ssh_identitylist *idlist;
1654 TAILQ_INIT(&agent); /* keys from the agent */
1655 TAILQ_INIT(&files); /* keys from the config file */
1656 preferred = &authctxt->keys;
1657 TAILQ_INIT(preferred); /* preferred order of keys */
1659 /* list of keys stored in the filesystem and PKCS#11 */
1660 for (i = 0; i < options.num_identity_files; i++) {
1661 key = options.identity_keys[i];
1662 if (key && key->cert &&
1663 key->cert->type != SSH2_CERT_TYPE_USER) {
1664 debug_f("ignoring certificate %s: not a user "
1665 "certificate", options.identity_files[i]);
1668 if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1669 debug_f("ignoring authenticator-hosted key %s as no "
1670 "SecurityKeyProvider has been specified",
1671 options.identity_files[i]);
1674 options.identity_keys[i] = NULL;
1675 id = xcalloc(1, sizeof(*id));
1678 id->filename = xstrdup(options.identity_files[i]);
1679 id->userprovided = options.identity_file_userprovided[i];
1680 TAILQ_INSERT_TAIL(&files, id, next);
1682 /* list of certificates specified by user */
1683 for (i = 0; i < options.num_certificate_files; i++) {
1684 key = options.certificates[i];
1685 if (!sshkey_is_cert(key) || key->cert == NULL ||
1686 key->cert->type != SSH2_CERT_TYPE_USER) {
1687 debug_f("ignoring certificate %s: not a user "
1688 "certificate", options.identity_files[i]);
1691 if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1692 debug_f("ignoring authenticator-hosted key "
1693 "certificate %s as no "
1694 "SecurityKeyProvider has been specified",
1695 options.identity_files[i]);
1698 id = xcalloc(1, sizeof(*id));
1701 id->filename = xstrdup(options.certificate_files[i]);
1702 id->userprovided = options.certificate_file_userprovided[i];
1703 TAILQ_INSERT_TAIL(preferred, id, next);
1705 /* list of keys supported by the agent */
1706 if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1707 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1708 debug_fr(r, "ssh_get_authentication_socket");
1709 } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1710 if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1711 debug_fr(r, "ssh_fetch_identitylist");
1714 for (j = 0; j < idlist->nkeys; j++) {
1716 TAILQ_FOREACH(id, &files, next) {
1718 * agent keys from the config file are
1721 if (sshkey_equal(idlist->keys[j], id->key)) {
1722 TAILQ_REMOVE(&files, id, next);
1723 TAILQ_INSERT_TAIL(preferred, id, next);
1724 id->agent_fd = agent_fd;
1729 if (!found && !options.identities_only) {
1730 id = xcalloc(1, sizeof(*id));
1731 /* XXX "steals" key/comment from idlist */
1732 id->key = idlist->keys[j];
1733 id->filename = idlist->comments[j];
1734 idlist->keys[j] = NULL;
1735 idlist->comments[j] = NULL;
1736 id->agent_fd = agent_fd;
1737 TAILQ_INSERT_TAIL(&agent, id, next);
1740 ssh_free_identitylist(idlist);
1741 /* append remaining agent keys */
1742 TAILQ_CONCAT(preferred, &agent, next);
1743 authctxt->agent_fd = agent_fd;
1745 /* Prefer PKCS11 keys that are explicitly listed */
1746 TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1747 if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1750 TAILQ_FOREACH(id2, &files, next) {
1751 if (id2->key == NULL ||
1752 (id2->key->flags & SSHKEY_FLAG_EXT) != 0)
1754 if (sshkey_equal(id->key, id2->key)) {
1755 TAILQ_REMOVE(&files, id, next);
1756 TAILQ_INSERT_TAIL(preferred, id, next);
1761 /* If IdentitiesOnly set and key not found then don't use it */
1762 if (!found && options.identities_only) {
1763 TAILQ_REMOVE(&files, id, next);
1764 freezero(id, sizeof(*id));
1767 /* append remaining keys from the config file */
1768 TAILQ_CONCAT(preferred, &files, next);
1769 /* finally, filter by PubkeyAcceptedAlgorithms */
1770 TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1771 if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1772 debug("Skipping %s key %s - "
1773 "corresponding algo not in PubkeyAcceptedAlgorithms",
1774 sshkey_ssh_name(id->key), id->filename);
1775 TAILQ_REMOVE(preferred, id, next);
1776 sshkey_free(id->key);
1778 memset(id, 0, sizeof(*id));
1782 /* List the keys we plan on using */
1783 TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1784 ident = format_identity(id);
1785 debug("Will attempt key: %s", ident);
1792 pubkey_cleanup(struct ssh *ssh)
1794 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1797 if (authctxt->agent_fd != -1) {
1798 ssh_close_authentication_socket(authctxt->agent_fd);
1799 authctxt->agent_fd = -1;
1801 for (id = TAILQ_FIRST(&authctxt->keys); id;
1802 id = TAILQ_FIRST(&authctxt->keys)) {
1803 TAILQ_REMOVE(&authctxt->keys, id, next);
1804 sshkey_free(id->key);
1811 pubkey_reset(Authctxt *authctxt)
1815 TAILQ_FOREACH(id, &authctxt->keys, next)
1820 try_identity(struct ssh *ssh, Identity *id)
1824 if (sshkey_type_plain(id->key->type) == KEY_RSA &&
1825 (ssh->compat & SSH_BUG_RSASIGMD5) != 0) {
1826 debug("Skipped %s key %s for RSA/MD5 server",
1827 sshkey_type(id->key), id->filename);
1834 userauth_pubkey(struct ssh *ssh)
1836 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1841 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1844 /* move key to the end of the queue */
1845 TAILQ_REMOVE(&authctxt->keys, id, next);
1846 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1848 * send a test message if we have the public key. for
1849 * encrypted keys we cannot do this and have to load the
1850 * private key instead
1852 if (id->key != NULL) {
1853 if (try_identity(ssh, id)) {
1854 ident = format_identity(id);
1855 debug("Offering public key: %s", ident);
1857 sent = send_pubkey_test(ssh, id);
1860 debug("Trying private key: %s", id->filename);
1861 id->key = load_identity_file(id);
1862 if (id->key != NULL) {
1863 if (try_identity(ssh, id)) {
1865 sent = sign_and_send_pubkey(ssh, id);
1867 sshkey_free(id->key);
1879 * Send userauth request message specifying keyboard-interactive method.
1882 userauth_kbdint(struct ssh *ssh)
1884 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1887 if (authctxt->attempt_kbdint++ >= options.number_of_password_prompts)
1889 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1890 if (authctxt->attempt_kbdint > 1 && !authctxt->info_req_seen) {
1891 debug3("userauth_kbdint: disable: no info_req_seen");
1892 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1896 debug2("userauth_kbdint");
1897 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1898 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1899 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1900 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1901 (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1902 (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1903 options.kbd_interactive_devices : "")) != 0 ||
1904 (r = sshpkt_send(ssh)) != 0)
1905 fatal_fr(r, "send packet");
1907 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1912 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1915 input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1917 Authctxt *authctxt = ssh->authctxt;
1918 char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1919 char *display_prompt = NULL, *response = NULL;
1921 u_int num_prompts, i;
1924 debug2_f("entering");
1926 if (authctxt == NULL)
1927 fatal_f("no authentication context");
1929 authctxt->info_req_seen = 1;
1931 if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1932 (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1933 (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1935 if (strlen(name) > 0)
1937 if (strlen(inst) > 0)
1940 if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1943 * Begin to build info response packet based on prompts requested.
1944 * We commit to providing the correct number of responses, so if
1945 * further on we run into a problem that prevents this, we have to
1946 * be sure and clean this up and send a correct error response.
1948 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1949 (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1952 debug2_f("num_prompts %d", num_prompts);
1953 for (i = 0; i < num_prompts; i++) {
1954 if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1955 (r = sshpkt_get_u8(ssh, &echo)) != 0)
1957 if (asmprintf(&display_prompt, INT_MAX, NULL, "(%s@%s) %s",
1958 authctxt->server_user, options.host_key_alias ?
1959 options.host_key_alias : authctxt->host, prompt) == -1)
1960 fatal_f("asmprintf failed");
1961 response = read_passphrase(display_prompt, echo ? RP_ECHO : 0);
1962 if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1964 freezero(response, strlen(response));
1966 free(display_prompt);
1967 display_prompt = response = prompt = NULL;
1969 /* done with parsing incoming message. */
1970 if ((r = sshpkt_get_end(ssh)) != 0 ||
1971 (r = sshpkt_add_padding(ssh, 64)) != 0)
1973 r = sshpkt_send(ssh);
1976 freezero(response, strlen(response));
1978 free(display_prompt);
1986 ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
1987 const u_char *data, size_t datalen)
1992 int r, to[2], from[2], status;
1993 int sock = ssh_packet_get_connection_in(ssh);
1994 u_char rversion = 0, version = 2;
1995 void (*osigchld)(int);
2000 if (stat(_PATH_SSH_KEY_SIGN, &st) == -1) {
2001 error_f("not installed: %s", strerror(errno));
2004 if (fflush(stdout) != 0) {
2005 error_f("fflush: %s", strerror(errno));
2008 if (pipe(to) == -1) {
2009 error_f("pipe: %s", strerror(errno));
2012 if (pipe(from) == -1) {
2013 error_f("pipe: %s", strerror(errno));
2016 if ((pid = fork()) == -1) {
2017 error_f("fork: %s", strerror(errno));
2020 osigchld = ssh_signal(SIGCHLD, SIG_DFL);
2023 if (dup2(from[1], STDOUT_FILENO) == -1)
2024 fatal_f("dup2: %s", strerror(errno));
2026 if (dup2(to[0], STDIN_FILENO) == -1)
2027 fatal_f("dup2: %s", strerror(errno));
2031 if (dup2(sock, STDERR_FILENO + 1) == -1)
2032 fatal_f("dup2: %s", strerror(errno));
2033 sock = STDERR_FILENO + 1;
2034 fcntl(sock, F_SETFD, 0); /* keep the socket on exec */
2035 closefrom(sock + 1);
2037 debug3_f("[child] pid=%ld, exec %s",
2038 (long)getpid(), _PATH_SSH_KEY_SIGN);
2039 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
2040 fatal_f("exec(%s): %s", _PATH_SSH_KEY_SIGN,
2045 sock = STDERR_FILENO + 1;
2047 if ((b = sshbuf_new()) == NULL)
2048 fatal_f("sshbuf_new failed");
2049 /* send # of sock, data to be signed */
2050 if ((r = sshbuf_put_u32(b, sock)) != 0 ||
2051 (r = sshbuf_put_string(b, data, datalen)) != 0)
2052 fatal_fr(r, "buffer error");
2053 if (ssh_msg_send(to[1], version, b) == -1)
2054 fatal_f("couldn't send request");
2056 r = ssh_msg_recv(from[0], b);
2060 error_f("no reply");
2065 while (waitpid(pid, &status, 0) == -1) {
2066 if (errno != EINTR) {
2067 error_f("waitpid %ld: %s", (long)pid, strerror(errno));
2071 if (!WIFEXITED(status)) {
2072 error_f("exited abnormally");
2075 if (WEXITSTATUS(status) != 0) {
2076 error_f("exited with status %d", WEXITSTATUS(status));
2079 if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
2080 error_fr(r, "buffer error");
2083 if (rversion != version) {
2084 error_f("bad version");
2087 if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
2088 error_fr(r, "buffer error");
2090 ssh_signal(SIGCHLD, osigchld);
2094 ssh_signal(SIGCHLD, osigchld);
2101 userauth_hostbased(struct ssh *ssh)
2103 Authctxt *authctxt = (Authctxt *)ssh->authctxt;
2104 struct sshkey *private = NULL;
2105 struct sshbuf *b = NULL;
2106 u_char *sig = NULL, *keyblob = NULL;
2107 char *fp = NULL, *chost = NULL, *lname = NULL;
2108 size_t siglen = 0, keylen = 0;
2109 int i, r, success = 0;
2111 if (authctxt->ktypes == NULL) {
2112 authctxt->oktypes = xstrdup(options.hostbased_accepted_algos);
2113 authctxt->ktypes = authctxt->oktypes;
2117 * Work through each listed type pattern in HostbasedAcceptedAlgorithms,
2118 * trying each hostkey that matches the type in turn.
2121 if (authctxt->active_ktype == NULL)
2122 authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
2123 if (authctxt->active_ktype == NULL ||
2124 *authctxt->active_ktype == '\0')
2126 debug3_f("trying key type %s", authctxt->active_ktype);
2128 /* check for a useful key */
2130 for (i = 0; i < authctxt->sensitive->nkeys; i++) {
2131 if (authctxt->sensitive->keys[i] == NULL ||
2132 authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
2134 if (match_pattern_list(
2135 sshkey_ssh_name(authctxt->sensitive->keys[i]),
2136 authctxt->active_ktype, 0) != 1)
2138 /* we take and free the key */
2139 private = authctxt->sensitive->keys[i];
2140 authctxt->sensitive->keys[i] = NULL;
2144 if (private != NULL)
2146 /* No more keys of this type; advance */
2147 authctxt->active_ktype = NULL;
2149 if (private == NULL) {
2150 free(authctxt->oktypes);
2151 authctxt->oktypes = authctxt->ktypes = NULL;
2152 authctxt->active_ktype = NULL;
2153 debug("No more client hostkeys for hostbased authentication.");
2157 if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
2158 SSH_FP_DEFAULT)) == NULL) {
2159 error_f("sshkey_fingerprint failed");
2162 debug_f("trying hostkey %s %s", sshkey_ssh_name(private), fp);
2164 /* figure out a name for the client host */
2165 lname = get_local_name(ssh_packet_get_connection_in(ssh));
2166 if (lname == NULL) {
2167 error_f("cannot get local ipaddr/name");
2171 /* XXX sshbuf_put_stringf? */
2172 xasprintf(&chost, "%s.", lname);
2173 debug2_f("chost %s", chost);
2175 /* construct data */
2176 if ((b = sshbuf_new()) == NULL) {
2177 error_f("sshbuf_new failed");
2180 if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
2181 error_fr(r, "sshkey_to_blob");
2184 if ((r = sshbuf_put_stringb(b, ssh->kex->session_id)) != 0 ||
2185 (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2186 (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
2187 (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
2188 (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
2189 (r = sshbuf_put_cstring(b, authctxt->active_ktype)) != 0 ||
2190 (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
2191 (r = sshbuf_put_cstring(b, chost)) != 0 ||
2192 (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
2193 error_fr(r, "buffer error");
2198 sshbuf_dump(b, stderr);
2200 if ((r = ssh_keysign(ssh, private, &sig, &siglen,
2201 sshbuf_ptr(b), sshbuf_len(b))) != 0) {
2202 error("sign using hostkey %s %s failed",
2203 sshkey_ssh_name(private), fp);
2206 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2207 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2208 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2209 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
2210 (r = sshpkt_put_cstring(ssh, authctxt->active_ktype)) != 0 ||
2211 (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2212 (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2213 (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2214 (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2215 (r = sshpkt_send(ssh)) != 0) {
2216 error_fr(r, "packet error");
2223 freezero(sig, siglen);
2228 sshkey_free(private);
2234 /* find auth method */
2237 * given auth method name, if configurable options permit this method fill
2238 * in auth_ident field and return true, otherwise return false.
2241 authmethod_is_enabled(Authmethod *method)
2245 /* return false if options indicate this method is disabled */
2246 if (method->enabled == NULL || *method->enabled == 0)
2248 /* return false if batch mode is enabled but method needs interactive mode */
2249 if (method->batch_flag != NULL && *method->batch_flag != 0)
2255 authmethod_lookup(const char *name)
2257 Authmethod *method = NULL;
2259 for (method = authmethods; method->name != NULL; method++)
2260 if (strcmp(name, method->name) == 0)
2262 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2266 /* XXX internal state */
2267 static Authmethod *current = NULL;
2268 static char *supported = NULL;
2269 static char *preferred = NULL;
2272 * Given the authentication method list sent by the server, return the
2273 * next method we should try. If the server initially sends a nil list,
2274 * use a built-in default list.
2277 authmethod_get(char *authlist)
2282 /* Use a suitable default if we're passed a nil list. */
2283 if (authlist == NULL || strlen(authlist) == 0)
2284 authlist = options.preferred_authentications;
2286 if (supported == NULL || strcmp(authlist, supported) != 0) {
2287 debug3("start over, passed a different list %s", authlist);
2289 supported = xstrdup(authlist);
2290 preferred = options.preferred_authentications;
2291 debug3("preferred %s", preferred);
2293 } else if (current != NULL && authmethod_is_enabled(current))
2297 if ((name = match_list(preferred, supported, &next)) == NULL) {
2298 debug("No more authentication methods to try.");
2303 debug3("authmethod_lookup %s", name);
2304 debug3("remaining preferred: %s", preferred);
2305 if ((current = authmethod_lookup(name)) != NULL &&
2306 authmethod_is_enabled(current)) {
2307 debug3("authmethod_is_enabled %s", name);
2308 debug("Next authentication method: %s", name);
2317 authmethods_get(void)
2319 Authmethod *method = NULL;
2324 if ((b = sshbuf_new()) == NULL)
2325 fatal_f("sshbuf_new failed");
2326 for (method = authmethods; method->name != NULL; method++) {
2327 if (authmethod_is_enabled(method)) {
2328 if ((r = sshbuf_putf(b, "%s%s",
2329 sshbuf_len(b) ? "," : "", method->name)) != 0)
2330 fatal_fr(r, "buffer error");
2333 if ((list = sshbuf_dup_string(b)) == NULL)
2334 fatal_f("sshbuf_dup_string failed");