1 /* $OpenBSD: sshconnect2.c,v 1.284 2018/08/13 02:41:05 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>
43 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
47 #include "openbsd-compat/sys-queue.h"
58 #include "myproposal.h"
59 #include "sshconnect.h"
70 #include "pathnames.h"
81 extern char *client_version_string;
82 extern char *server_version_string;
83 extern Options options;
89 u_char *session_id2 = NULL;
90 u_int session_id2_len = 0;
93 struct sockaddr *xxx_hostaddr;
96 verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
98 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
99 fatal("Host key verification failed.");
104 order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
106 char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
108 struct hostkeys *hostkeys;
112 /* Find all hostkeys for this hostname */
113 get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
114 hostkeys = init_hostkeys();
115 for (i = 0; i < options.num_user_hostfiles; i++)
116 load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
117 for (i = 0; i < options.num_system_hostfiles; i++)
118 load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
120 oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
121 maxlen = strlen(avail) + 1;
122 first = xmalloc(maxlen);
123 last = xmalloc(maxlen);
124 *first = *last = '\0';
126 #define ALG_APPEND(to, from) \
129 strlcat(to, ",", maxlen); \
130 strlcat(to, from, maxlen); \
133 while ((alg = strsep(&avail, ",")) && *alg != '\0') {
134 if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
135 fatal("%s: unknown alg %s", __func__, alg);
136 if (lookup_key_in_hostkeys_by_type(hostkeys,
137 sshkey_type_plain(ktype), NULL))
138 ALG_APPEND(first, alg);
140 ALG_APPEND(last, alg);
143 xasprintf(&ret, "%s%s%s", first,
144 (*first == '\0' || *last == '\0') ? "" : ",", last);
146 debug3("%s: prefer hostkeyalgs: %s", __func__, first);
152 free_hostkeys(hostkeys);
158 ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
160 char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
166 xxx_hostaddr = hostaddr;
168 if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
169 fatal("%s: kex_names_cat", __func__);
170 myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s);
171 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
172 compat_cipher_proposal(options.ciphers);
173 myproposal[PROPOSAL_ENC_ALGS_STOC] =
174 compat_cipher_proposal(options.ciphers);
175 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
176 myproposal[PROPOSAL_COMP_ALGS_STOC] = options.compression ?
177 "zlib@openssh.com,zlib,none" : "none,zlib@openssh.com,zlib";
178 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
179 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
180 if (options.hostkeyalgorithms != NULL) {
181 all_key = sshkey_alg_list(0, 0, 1, ',');
182 if (kex_assemble_names(&options.hostkeyalgorithms,
183 KEX_DEFAULT_PK_ALG, all_key) != 0)
184 fatal("%s: kex_assemble_namelist", __func__);
186 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
187 compat_pkalg_proposal(options.hostkeyalgorithms);
189 /* Enforce default */
190 options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG);
191 /* Prefer algorithms that we already have keys for */
192 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
193 compat_pkalg_proposal(
194 order_hostkeyalgs(host, hostaddr, port));
197 if (options.rekey_limit || options.rekey_interval)
198 packet_set_rekey_limits(options.rekey_limit,
199 options.rekey_interval);
201 /* start key exchange */
202 if ((r = kex_setup(active_state, myproposal)) != 0)
203 fatal("kex_setup: %s", ssh_err(r));
204 kex = active_state->kex;
206 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
207 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
208 kex->kex[KEX_DH_GRP14_SHA256] = kexdh_client;
209 kex->kex[KEX_DH_GRP16_SHA512] = kexdh_client;
210 kex->kex[KEX_DH_GRP18_SHA512] = kexdh_client;
211 kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
212 kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
213 # ifdef OPENSSL_HAS_ECC
214 kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
217 kex->kex[KEX_C25519_SHA256] = kexc25519_client;
218 kex->client_version_string=client_version_string;
219 kex->server_version_string=server_version_string;
220 kex->verify_host_key=&verify_host_key_callback;
222 ssh_dispatch_run_fatal(active_state, DISPATCH_BLOCK, &kex->done);
224 /* remove ext-info from the KEX proposals for rekeying */
225 myproposal[PROPOSAL_KEX_ALGS] =
226 compat_kex_proposal(options.kex_algorithms);
227 if ((r = kex_prop2buf(kex->my, myproposal)) != 0)
228 fatal("kex_prop2buf: %s", ssh_err(r));
230 session_id2 = kex->session_id;
231 session_id2_len = kex->session_id_len;
234 /* send 1st encrypted/maced/compressed message */
235 if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
236 (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
237 (r = sshpkt_send(ssh)) != 0 ||
238 (r = ssh_packet_write_wait(ssh)) != 0)
239 fatal("%s: %s", __func__, ssh_err(r));
247 typedef struct cauthctxt Authctxt;
248 typedef struct cauthmethod Authmethod;
249 typedef struct identity Identity;
250 typedef struct idlist Idlist;
253 TAILQ_ENTRY(identity) next;
254 int agent_fd; /* >=0 if agent supports key */
255 struct sshkey *key; /* public/private key */
256 char *filename; /* comment for agent-only keys */
258 int isprivate; /* key points to the private key */
261 TAILQ_HEAD(idlist, identity);
264 const char *server_user;
265 const char *local_user;
268 struct cauthmethod *method;
269 sig_atomic_t success;
276 Sensitive *sensitive;
277 char *oktypes, *ktypes;
278 const char *active_ktype;
279 /* kbd-interactive */
286 char *name; /* string to compare against server's list */
287 int (*userauth)(Authctxt *authctxt);
288 void (*cleanup)(Authctxt *authctxt);
289 int *enabled; /* flag in option struct that enables method */
290 int *batch_flag; /* flag in option struct that disables method */
293 int input_userauth_service_accept(int, u_int32_t, struct ssh *);
294 int input_userauth_ext_info(int, u_int32_t, struct ssh *);
295 int input_userauth_success(int, u_int32_t, struct ssh *);
296 int input_userauth_success_unexpected(int, u_int32_t, struct ssh *);
297 int input_userauth_failure(int, u_int32_t, struct ssh *);
298 int input_userauth_banner(int, u_int32_t, struct ssh *);
299 int input_userauth_error(int, u_int32_t, struct ssh *);
300 int input_userauth_info_req(int, u_int32_t, struct ssh *);
301 int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
302 int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
304 int userauth_none(Authctxt *);
305 int userauth_pubkey(Authctxt *);
306 int userauth_passwd(Authctxt *);
307 int userauth_kbdint(Authctxt *);
308 int userauth_hostbased(Authctxt *);
311 int userauth_gssapi(Authctxt *authctxt);
312 int input_gssapi_response(int type, u_int32_t, struct ssh *);
313 int input_gssapi_token(int type, u_int32_t, struct ssh *);
314 int input_gssapi_hash(int type, u_int32_t, struct ssh *);
315 int input_gssapi_error(int, u_int32_t, struct ssh *);
316 int input_gssapi_errtok(int, u_int32_t, struct ssh *);
319 void userauth(Authctxt *, char *);
321 static int sign_and_send_pubkey(struct ssh *ssh, Authctxt *, Identity *);
322 static void pubkey_prepare(Authctxt *);
323 static void pubkey_cleanup(Authctxt *);
324 static void pubkey_reset(Authctxt *);
325 static struct sshkey *load_identity_file(Identity *);
327 static Authmethod *authmethod_get(char *authlist);
328 static Authmethod *authmethod_lookup(const char *name);
329 static char *authmethods_get(void);
331 Authmethod authmethods[] = {
336 &options.gss_authentication,
342 &options.hostbased_authentication,
347 &options.pubkey_authentication,
349 {"keyboard-interactive",
352 &options.kbd_interactive_authentication,
353 &options.batch_mode},
357 &options.password_authentication,
358 &options.batch_mode},
364 {NULL, NULL, NULL, NULL, NULL}
368 ssh_userauth2(const char *local_user, const char *server_user, char *host,
369 Sensitive *sensitive)
371 struct ssh *ssh = active_state;
375 if (options.challenge_response_authentication)
376 options.kbd_interactive_authentication = 1;
377 if (options.preferred_authentications == NULL)
378 options.preferred_authentications = authmethods_get();
380 /* setup authentication context */
381 memset(&authctxt, 0, sizeof(authctxt));
382 pubkey_prepare(&authctxt);
383 authctxt.server_user = server_user;
384 authctxt.local_user = local_user;
385 authctxt.host = host;
386 authctxt.service = "ssh-connection"; /* service name */
387 authctxt.success = 0;
388 authctxt.method = authmethod_lookup("none");
389 authctxt.authlist = NULL;
390 authctxt.methoddata = NULL;
391 authctxt.sensitive = sensitive;
392 authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
393 authctxt.info_req_seen = 0;
394 authctxt.agent_fd = -1;
395 if (authctxt.method == NULL)
396 fatal("ssh_userauth2: internal error: cannot send userauth none request");
398 if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
399 (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
400 (r = sshpkt_send(ssh)) != 0)
401 fatal("%s: %s", __func__, ssh_err(r));
403 ssh->authctxt = &authctxt;
404 ssh_dispatch_init(ssh, &input_userauth_error);
405 ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
406 ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
407 ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
408 ssh->authctxt = NULL;
410 pubkey_cleanup(&authctxt);
411 ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
413 if (!authctxt.success)
414 fatal("Authentication failed.");
415 debug("Authentication succeeded (%s).", authctxt.method->name);
420 input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
422 Authctxt *authctxt = ssh->authctxt;
425 if (ssh_packet_remaining(ssh) > 0) {
428 if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
430 debug2("service_accept: %s", reply);
433 debug2("buggy server: service_accept w/o service");
435 if ((r = sshpkt_get_end(ssh)) != 0)
437 debug("SSH2_MSG_SERVICE_ACCEPT received");
439 /* initial userauth request */
440 userauth_none(authctxt);
442 ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
443 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
444 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
445 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
453 input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
455 return kex_input_ext_info(type, seqnr, ssh);
459 userauth(Authctxt *authctxt, char *authlist)
461 struct ssh *ssh = active_state; /* XXX */
463 if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
464 authctxt->method->cleanup(authctxt);
466 free(authctxt->methoddata);
467 authctxt->methoddata = NULL;
468 if (authlist == NULL) {
469 authlist = authctxt->authlist;
471 free(authctxt->authlist);
472 authctxt->authlist = authlist;
475 Authmethod *method = authmethod_get(authlist);
477 fatal("%s@%s: Permission denied (%s).",
478 authctxt->server_user, authctxt->host, authlist);
479 authctxt->method = method;
481 /* reset the per method handler */
482 ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
483 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
485 /* and try new method */
486 if (method->userauth(authctxt) != 0) {
487 debug2("we sent a %s packet, wait for reply", method->name);
490 debug2("we did not send a packet, disable method");
491 method->enabled = NULL;
498 input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
500 fatal("input_userauth_error: bad message during authentication: "
507 input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
512 debug3("%s", __func__);
513 msg = packet_get_string(&len);
514 lang = packet_get_string(NULL);
515 if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
516 fmprintf(stderr, "%s", msg);
524 input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
526 Authctxt *authctxt = ssh->authctxt;
528 if (authctxt == NULL)
529 fatal("input_userauth_success: no authentication context");
530 free(authctxt->authlist);
531 authctxt->authlist = NULL;
532 if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
533 authctxt->method->cleanup(authctxt);
534 free(authctxt->methoddata);
535 authctxt->methoddata = NULL;
536 authctxt->success = 1; /* break out */
541 input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
543 Authctxt *authctxt = ssh->authctxt;
545 if (authctxt == NULL)
546 fatal("%s: no authentication context", __func__);
548 fatal("Unexpected authentication success during %s.",
549 authctxt->method->name);
555 input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
557 Authctxt *authctxt = ssh->authctxt;
558 char *authlist = NULL;
562 if (authctxt == NULL)
563 fatal("input_userauth_failure: no authentication context");
565 if ((r = sshpkt_get_cstring(ssh, &authlist, NULL)) != 0 ||
566 (r = sshpkt_get_u8(ssh, &partial)) != 0 ||
567 (r = sshpkt_get_end(ssh)) != 0)
571 verbose("Authenticated with partial success.");
573 pubkey_reset(authctxt);
575 debug("Authentications that can continue: %s", authlist);
577 userauth(authctxt, authlist);
586 input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
588 Authctxt *authctxt = ssh->authctxt;
589 struct sshkey *key = NULL;
591 int pktype, sent = 0;
593 char *pkalg = NULL, *fp;
594 u_char *pkblob = NULL;
597 if (authctxt == NULL)
598 fatal("input_userauth_pk_ok: no authentication context");
600 if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
601 (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
602 (r = sshpkt_get_end(ssh)) != 0)
605 debug("Server accepts key: pkalg %s blen %zu", pkalg, blen);
607 if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
608 debug("unknown pkalg %s", pkalg);
611 if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
612 debug("no key from blob. pkalg %s: %s", pkalg, ssh_err(r));
615 if (key->type != pktype) {
616 error("input_userauth_pk_ok: type mismatch "
617 "for decoded key (received %d, expected %d)",
621 if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
622 SSH_FP_DEFAULT)) == NULL)
624 debug2("input_userauth_pk_ok: fp %s", fp);
628 * search keys in the reverse order, because last candidate has been
629 * moved to the end of the queue. this also avoids confusion by
632 TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
633 if (sshkey_equal(key, id->key)) {
634 sent = sign_and_send_pubkey(ssh, authctxt, id);
644 /* try another method if we did not send a packet */
645 if (r == 0 && sent == 0)
646 userauth(authctxt, NULL);
652 userauth_gssapi(Authctxt *authctxt)
654 struct ssh *ssh = active_state; /* XXX */
655 Gssctxt *gssctxt = NULL;
656 static gss_OID_set gss_supported = NULL;
657 static u_int mech = 0;
661 /* Try one GSSAPI method at a time, rather than sending them all at
664 if (gss_supported == NULL)
665 gss_indicate_mechs(&min, &gss_supported);
667 /* Check to see if the mechanism is usable before we offer it */
668 while (mech < gss_supported->count && !ok) {
669 /* My DER encoding requires length<128 */
670 if (gss_supported->elements[mech].length < 128 &&
671 ssh_gssapi_check_mechanism(&gssctxt,
672 &gss_supported->elements[mech], authctxt->host)) {
673 ok = 1; /* Mechanism works */
682 authctxt->methoddata=(void *)gssctxt;
684 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
685 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
686 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
687 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
688 (r = sshpkt_put_u32(ssh, 1)) != 0 ||
689 (r = sshpkt_put_u32(ssh,
690 (gss_supported->elements[mech].length) + 2)) != 0 ||
691 (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
692 (r = sshpkt_put_u8(ssh,
693 gss_supported->elements[mech].length)) != 0 ||
695 gss_supported->elements[mech].elements,
696 gss_supported->elements[mech].length)) != 0 ||
697 (r = sshpkt_send(ssh)) != 0)
698 fatal("%s: %s", __func__, ssh_err(r));
700 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
701 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
702 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
703 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
705 mech++; /* Move along to next candidate */
711 process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
713 Authctxt *authctxt = ssh->authctxt;
714 Gssctxt *gssctxt = authctxt->methoddata;
715 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
716 gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
717 gss_buffer_desc gssbuf;
718 OM_uint32 status, ms, flags;
721 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
722 recv_tok, &send_tok, &flags);
724 if (send_tok.length > 0) {
725 u_char type = GSS_ERROR(status) ?
726 SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
727 SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
729 if ((r = sshpkt_start(ssh, type)) != 0 ||
730 (r = sshpkt_put_string(ssh, send_tok.value,
731 send_tok.length)) != 0 ||
732 (r = sshpkt_send(ssh)) != 0)
733 fatal("%s: %s", __func__, ssh_err(r));
735 gss_release_buffer(&ms, &send_tok);
738 if (status == GSS_S_COMPLETE) {
739 /* send either complete or MIC, depending on mechanism */
740 if (!(flags & GSS_C_INTEG_FLAG)) {
741 if ((r = sshpkt_start(ssh,
742 SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
743 (r = sshpkt_send(ssh)) != 0)
744 fatal("%s: %s", __func__, ssh_err(r));
748 if ((b = sshbuf_new()) == NULL)
749 fatal("%s: sshbuf_new failed", __func__);
750 ssh_gssapi_buildmic(b, authctxt->server_user,
751 authctxt->service, "gssapi-with-mic");
753 if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
754 fatal("%s: sshbuf_mutable_ptr failed", __func__);
755 gssbuf.length = sshbuf_len(b);
757 status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
759 if (!GSS_ERROR(status)) {
760 if ((r = sshpkt_start(ssh,
761 SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
762 (r = sshpkt_put_string(ssh, mic.value,
764 (r = sshpkt_send(ssh)) != 0)
765 fatal("%s: %s", __func__, ssh_err(r));
769 gss_release_buffer(&ms, &mic);
778 input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
780 Authctxt *authctxt = ssh->authctxt;
786 if (authctxt == NULL)
787 fatal("input_gssapi_response: no authentication context");
788 gssctxt = authctxt->methoddata;
791 if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
795 oidv[0] != SSH_GSS_OIDTYPE ||
796 oidv[1] != oidlen - 2) {
797 debug("Badly encoded mechanism OID received");
798 userauth(authctxt, NULL);
802 if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
803 fatal("Server returned different OID than expected");
805 if ((r = sshpkt_get_end(ssh)) != 0)
808 if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
809 /* Start again with next method on list */
810 debug("Trying to start again");
811 userauth(authctxt, NULL);
823 input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
825 Authctxt *authctxt = ssh->authctxt;
826 gss_buffer_desc recv_tok;
832 if (authctxt == NULL)
833 fatal("input_gssapi_response: no authentication context");
835 if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
836 (r = sshpkt_get_end(ssh)) != 0)
840 recv_tok.length = len;
841 status = process_gssapi_token(ssh, &recv_tok);
843 /* Start again with the next method in the list */
844 if (GSS_ERROR(status)) {
845 userauth(authctxt, NULL);
856 input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
858 Authctxt *authctxt = ssh->authctxt;
860 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
861 gss_buffer_desc recv_tok;
867 if (authctxt == NULL)
868 fatal("input_gssapi_response: no authentication context");
869 gssctxt = authctxt->methoddata;
871 if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
872 (r = sshpkt_get_end(ssh)) != 0) {
877 /* Stick it into GSSAPI and see what it says */
879 recv_tok.length = len;
880 (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
881 &recv_tok, &send_tok, NULL);
883 gss_release_buffer(&ms, &send_tok);
885 /* Server will be returning a failed packet after this one */
891 input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
897 if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
898 (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
899 (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
900 (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
902 r = sshpkt_get_end(ssh);
903 debug("Server GSSAPI Error:\n%s", msg);
912 userauth_none(Authctxt *authctxt)
914 struct ssh *ssh = active_state; /* XXX */
917 /* initial userauth request */
918 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
919 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
920 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
921 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
922 (r = sshpkt_send(ssh)) != 0)
923 fatal("%s: %s", __func__, ssh_err(r));
928 userauth_passwd(Authctxt *authctxt)
930 struct ssh *ssh = active_state; /* XXX */
931 static int attempt = 0;
934 const char *host = options.host_key_alias ? options.host_key_alias :
938 if (attempt++ >= options.number_of_password_prompts)
942 error("Permission denied, please try again.");
944 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
945 authctxt->server_user, host);
946 password = read_passphrase(prompt, 0);
947 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
948 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
949 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
950 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
951 (r = sshpkt_put_u8(ssh, 0)) != 0 ||
952 (r = sshpkt_put_cstring(ssh, password)) != 0 ||
953 (r = sshpkt_add_padding(ssh, 64)) != 0 ||
954 (r = sshpkt_send(ssh)) != 0)
955 fatal("%s: %s", __func__, ssh_err(r));
958 freezero(password, strlen(password));
960 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
961 &input_userauth_passwd_changereq);
967 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
971 input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
973 Authctxt *authctxt = ssh->authctxt;
974 char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
979 debug2("input_userauth_passwd_changereq");
981 if (authctxt == NULL)
982 fatal("input_userauth_passwd_changereq: "
983 "no authentication context");
984 host = options.host_key_alias ? options.host_key_alias : authctxt->host;
986 if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
987 (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
989 if (strlen(info) > 0)
991 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
992 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
993 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
994 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
995 (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
998 snprintf(prompt, sizeof(prompt),
999 "Enter %.30s@%.128s's old password: ",
1000 authctxt->server_user, host);
1001 password = read_passphrase(prompt, 0);
1002 if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1005 freezero(password, strlen(password));
1007 while (password == NULL) {
1008 snprintf(prompt, sizeof(prompt),
1009 "Enter %.30s@%.128s's new password: ",
1010 authctxt->server_user, host);
1011 password = read_passphrase(prompt, RP_ALLOW_EOF);
1012 if (password == NULL) {
1017 snprintf(prompt, sizeof(prompt),
1018 "Retype %.30s@%.128s's new password: ",
1019 authctxt->server_user, host);
1020 retype = read_passphrase(prompt, 0);
1021 if (strcmp(password, retype) != 0) {
1022 freezero(password, strlen(password));
1023 logit("Mismatch; try again, EOF to quit.");
1026 freezero(retype, strlen(retype));
1028 if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1029 (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1030 (r = sshpkt_send(ssh)) != 0)
1033 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1034 &input_userauth_passwd_changereq);
1038 freezero(password, strlen(password));
1045 * Select an algorithm for publickey signatures.
1046 * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1048 * Call with ssh==NULL to ignore server-sig-algs extension list and
1049 * only attempt with the key's base signature type.
1052 key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1054 char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1057 * The signature algorithm will only differ from the key algorithm
1058 * for RSA keys/certs and when the server advertises support for
1059 * newer (SHA2) algorithms.
1061 if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1062 (key->type != KEY_RSA && key->type != KEY_RSA_CERT)) {
1063 /* Filter base key signature alg against our configuration */
1064 return match_list(sshkey_ssh_name(key),
1065 options.pubkey_key_types, NULL);
1069 * For RSA keys/certs, since these might have a different sig type:
1070 * find the first entry in PubkeyAcceptedKeyTypes of the right type
1071 * that also appears in the supported signature algorithms list from
1074 oallowed = allowed = xstrdup(options.pubkey_key_types);
1075 while ((cp = strsep(&allowed, ",")) != NULL) {
1076 if (sshkey_type_from_name(cp) != key->type)
1078 tmp = match_list(sshkey_sigalg_by_name(cp), ssh->kex->server_sig_algs, NULL);
1090 identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1091 const u_char *data, size_t datalen, u_int compat, const char *alg)
1096 /* The agent supports this key. */
1097 if (id->key != NULL && id->agent_fd != -1) {
1098 return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1099 data, datalen, alg, compat);
1103 * We have already loaded the private key or the private key is
1104 * stored in external hardware.
1106 if (id->key != NULL &&
1107 (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1108 if ((r = sshkey_sign(id->key, sigp, lenp, data, datalen,
1112 * PKCS#11 tokens may not support all signature algorithms,
1113 * so check what we get back.
1115 if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0)
1120 /* Load the private key from the file. */
1121 if ((prv = load_identity_file(id)) == NULL)
1122 return SSH_ERR_KEY_NOT_FOUND;
1123 if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1124 error("%s: private key %s contents do not match public",
1125 __func__, id->filename);
1126 return SSH_ERR_KEY_NOT_FOUND;
1128 r = sshkey_sign(prv, sigp, lenp, data, datalen, alg, compat);
1134 id_filename_matches(Identity *id, Identity *private_id)
1136 const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1137 size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1140 if (strcmp(id->filename, private_id->filename) == 0)
1142 for (i = 0; suffixes[i]; i++) {
1143 slen = strlen(suffixes[i]);
1144 if (len > slen && plen == len - slen &&
1145 strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1146 memcmp(id->filename, private_id->filename, plen) == 0)
1153 sign_and_send_pubkey(struct ssh *ssh, Authctxt *authctxt, Identity *id)
1155 struct sshbuf *b = NULL;
1156 Identity *private_id, *sign_id = NULL;
1157 u_char *signature = NULL;
1158 size_t slen = 0, skip = 0;
1159 int r, fallback_sigtype, sent = 0;
1160 char *alg = NULL, *fp = NULL;
1161 const char *loc = "";
1163 if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1164 SSH_FP_DEFAULT)) == NULL)
1167 debug3("%s: %s %s", __func__, sshkey_type(id->key), fp);
1170 * If the key is an certificate, try to find a matching private key
1171 * and use it to complete the signature.
1172 * If no such private key exists, fall back to trying the certificate
1173 * key itself in case it has a private half already loaded.
1174 * This will try to set sign_id to the private key that will perform
1177 if (sshkey_is_cert(id->key)) {
1178 TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1179 if (sshkey_equal_public(id->key, private_id->key) &&
1180 id->key->type != private_id->key->type) {
1181 sign_id = private_id;
1186 * Exact key matches are preferred, but also allow
1187 * filename matches for non-PKCS#11/agent keys that
1188 * didn't load public keys. This supports the case
1189 * of keeping just a private key file and public
1190 * certificate on disk.
1192 if (sign_id == NULL &&
1193 !id->isprivate && id->agent_fd == -1 &&
1194 (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1195 TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1196 if (private_id->key == NULL &&
1197 id_filename_matches(id, private_id)) {
1198 sign_id = private_id;
1203 if (sign_id != NULL) {
1204 debug2("%s: using private key \"%s\"%s for "
1205 "certificate", __func__, id->filename,
1206 id->agent_fd != -1 ? " from agent" : "");
1208 debug("%s: no separate private key for certificate "
1209 "\"%s\"", __func__, id->filename);
1214 * If the above didn't select another identity to do the signing
1215 * then default to the one we started with.
1217 if (sign_id == NULL)
1220 /* assemble and sign data */
1221 for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1225 if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1226 id->key)) == NULL) {
1227 error("%s: no mutual signature supported", __func__);
1230 debug3("%s: signing using %s", __func__, alg);
1233 if ((b = sshbuf_new()) == NULL)
1234 fatal("%s: sshbuf_new failed", __func__);
1235 if (datafellows & SSH_OLD_SESSIONID) {
1236 if ((r = sshbuf_put(b, session_id2,
1237 session_id2_len)) != 0) {
1238 fatal("%s: sshbuf_put: %s",
1239 __func__, ssh_err(r));
1242 if ((r = sshbuf_put_string(b, session_id2,
1243 session_id2_len)) != 0) {
1244 fatal("%s: sshbuf_put_string: %s",
1245 __func__, ssh_err(r));
1248 skip = sshbuf_len(b);
1249 if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1250 (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1251 (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1252 (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1253 (r = sshbuf_put_u8(b, 1)) != 0 ||
1254 (r = sshbuf_put_cstring(b, alg)) != 0 ||
1255 (r = sshkey_puts(id->key, b)) != 0) {
1256 fatal("%s: assemble signed data: %s",
1257 __func__, ssh_err(r));
1260 /* generate signature */
1261 r = identity_sign(sign_id, &signature, &slen,
1262 sshbuf_ptr(b), sshbuf_len(b), datafellows, alg);
1265 else if (r == SSH_ERR_KEY_NOT_FOUND)
1266 goto out; /* soft failure */
1267 else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1268 !fallback_sigtype) {
1269 if (sign_id->agent_fd != -1)
1271 else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1273 logit("%skey %s %s returned incorrect signature type",
1274 loc, sshkey_type(id->key), fp);
1277 error("%s: signing failed: %s", __func__, ssh_err(r));
1280 if (slen == 0 || signature == NULL) /* shouldn't happen */
1281 fatal("%s: no signature", __func__);
1283 /* append signature */
1284 if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1285 fatal("%s: append signature: %s", __func__, ssh_err(r));
1288 sshbuf_dump(b, stderr);
1290 /* skip session id and packet type */
1291 if ((r = sshbuf_consume(b, skip + 1)) != 0)
1292 fatal("%s: consume: %s", __func__, ssh_err(r));
1294 /* put remaining data from buffer into packet */
1295 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1296 (r = sshpkt_putb(ssh, b)) != 0 ||
1297 (r = sshpkt_send(ssh)) != 0)
1298 fatal("%s: enqueue request: %s", __func__, ssh_err(r));
1307 freezero(signature, slen);
1312 send_pubkey_test(struct ssh *ssh, Authctxt *authctxt, Identity *id)
1314 u_char *blob = NULL;
1320 if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1321 debug("%s: no mutual signature algorithm", __func__);
1325 if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1326 /* we cannot handle this key */
1327 debug3("%s: cannot handle key", __func__);
1330 /* register callback for USERAUTH_PK_OK message */
1331 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1333 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1334 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1335 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1336 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1337 (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1338 (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1339 (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1340 (r = sshpkt_send(ssh)) != 0)
1341 fatal("%s: %s", __func__, ssh_err(r));
1350 static struct sshkey *
1351 load_identity_file(Identity *id)
1353 struct sshkey *private = NULL;
1354 char prompt[300], *passphrase, *comment;
1355 int r, perm_ok = 0, quit = 0, i;
1358 if (stat(id->filename, &st) < 0) {
1359 (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1360 id->filename, strerror(errno));
1363 snprintf(prompt, sizeof prompt,
1364 "Enter passphrase for key '%.100s': ", id->filename);
1365 for (i = 0; i <= options.number_of_password_prompts; i++) {
1369 passphrase = read_passphrase(prompt, 0);
1370 if (*passphrase == '\0') {
1371 debug2("no passphrase given, try next key");
1376 switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1377 passphrase, &private, &comment, &perm_ok))) {
1380 case SSH_ERR_KEY_WRONG_PASSPHRASE:
1381 if (options.batch_mode) {
1386 debug2("bad passphrase given, try again...");
1388 case SSH_ERR_SYSTEM_ERROR:
1389 if (errno == ENOENT) {
1390 debug2("Load key \"%s\": %s",
1391 id->filename, ssh_err(r));
1397 error("Load key \"%s\": %s", id->filename, ssh_err(r));
1401 if (!quit && private != NULL && id->agent_fd == -1 &&
1402 !(id->key && id->isprivate))
1403 maybe_add_key_to_agent(id->filename, private, comment,
1406 freezero(passphrase, strlen(passphrase));
1408 if (private != NULL || quit)
1415 key_type_allowed_by_config(struct sshkey *key)
1417 if (match_pattern_list(sshkey_ssh_name(key),
1418 options.pubkey_key_types, 0) == 1)
1421 /* RSA keys/certs might be allowed by alternate signature types */
1422 switch (key->type) {
1424 if (match_pattern_list("rsa-sha2-512",
1425 options.pubkey_key_types, 0) == 1)
1427 if (match_pattern_list("rsa-sha2-256",
1428 options.pubkey_key_types, 0) == 1)
1432 if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1433 options.pubkey_key_types, 0) == 1)
1435 if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1436 options.pubkey_key_types, 0) == 1)
1445 * try keys in the following order:
1446 * 1. certificates listed in the config file
1447 * 2. other input certificates
1448 * 3. agent keys that are found in the config file
1449 * 4. other agent keys
1450 * 5. keys that are only listed in the config file
1453 pubkey_prepare(Authctxt *authctxt)
1455 struct identity *id, *id2, *tmp;
1456 struct idlist agent, files, *preferred;
1458 int agent_fd = -1, i, r, found;
1460 struct ssh_identitylist *idlist;
1462 TAILQ_INIT(&agent); /* keys from the agent */
1463 TAILQ_INIT(&files); /* keys from the config file */
1464 preferred = &authctxt->keys;
1465 TAILQ_INIT(preferred); /* preferred order of keys */
1467 /* list of keys stored in the filesystem and PKCS#11 */
1468 for (i = 0; i < options.num_identity_files; i++) {
1469 key = options.identity_keys[i];
1470 if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1472 options.identity_keys[i] = NULL;
1473 id = xcalloc(1, sizeof(*id));
1476 id->filename = xstrdup(options.identity_files[i]);
1477 id->userprovided = options.identity_file_userprovided[i];
1478 TAILQ_INSERT_TAIL(&files, id, next);
1480 /* list of certificates specified by user */
1481 for (i = 0; i < options.num_certificate_files; i++) {
1482 key = options.certificates[i];
1483 if (!sshkey_is_cert(key) || key->cert == NULL ||
1484 key->cert->type != SSH2_CERT_TYPE_USER)
1486 id = xcalloc(1, sizeof(*id));
1489 id->filename = xstrdup(options.certificate_files[i]);
1490 id->userprovided = options.certificate_file_userprovided[i];
1491 TAILQ_INSERT_TAIL(preferred, id, next);
1493 /* list of keys supported by the agent */
1494 if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1495 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1496 debug("%s: ssh_get_authentication_socket: %s",
1497 __func__, ssh_err(r));
1498 } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1499 if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1500 debug("%s: ssh_fetch_identitylist: %s",
1501 __func__, ssh_err(r));
1504 for (j = 0; j < idlist->nkeys; j++) {
1506 TAILQ_FOREACH(id, &files, next) {
1508 * agent keys from the config file are
1511 if (sshkey_equal(idlist->keys[j], id->key)) {
1512 TAILQ_REMOVE(&files, id, next);
1513 TAILQ_INSERT_TAIL(preferred, id, next);
1514 id->agent_fd = agent_fd;
1519 if (!found && !options.identities_only) {
1520 id = xcalloc(1, sizeof(*id));
1521 /* XXX "steals" key/comment from idlist */
1522 id->key = idlist->keys[j];
1523 id->filename = idlist->comments[j];
1524 idlist->keys[j] = NULL;
1525 idlist->comments[j] = NULL;
1526 id->agent_fd = agent_fd;
1527 TAILQ_INSERT_TAIL(&agent, id, next);
1530 ssh_free_identitylist(idlist);
1531 /* append remaining agent keys */
1532 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1533 TAILQ_REMOVE(&agent, id, next);
1534 TAILQ_INSERT_TAIL(preferred, id, next);
1536 authctxt->agent_fd = agent_fd;
1538 /* Prefer PKCS11 keys that are explicitly listed */
1539 TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1540 if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1543 TAILQ_FOREACH(id2, &files, next) {
1544 if (id2->key == NULL ||
1545 (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1547 if (sshkey_equal(id->key, id2->key)) {
1548 TAILQ_REMOVE(&files, id, next);
1549 TAILQ_INSERT_TAIL(preferred, id, next);
1554 /* If IdentitiesOnly set and key not found then don't use it */
1555 if (!found && options.identities_only) {
1556 TAILQ_REMOVE(&files, id, next);
1557 freezero(id, sizeof(*id));
1560 /* append remaining keys from the config file */
1561 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1562 TAILQ_REMOVE(&files, id, next);
1563 TAILQ_INSERT_TAIL(preferred, id, next);
1565 /* finally, filter by PubkeyAcceptedKeyTypes */
1566 TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1567 if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1568 debug("Skipping %s key %s - "
1569 "not in PubkeyAcceptedKeyTypes",
1570 sshkey_ssh_name(id->key), id->filename);
1571 TAILQ_REMOVE(preferred, id, next);
1572 sshkey_free(id->key);
1574 memset(id, 0, sizeof(*id));
1577 debug2("key: %s (%p)%s%s", id->filename, id->key,
1578 id->userprovided ? ", explicit" : "",
1579 id->agent_fd != -1 ? ", agent" : "");
1584 pubkey_cleanup(Authctxt *authctxt)
1588 if (authctxt->agent_fd != -1)
1589 ssh_close_authentication_socket(authctxt->agent_fd);
1590 for (id = TAILQ_FIRST(&authctxt->keys); id;
1591 id = TAILQ_FIRST(&authctxt->keys)) {
1592 TAILQ_REMOVE(&authctxt->keys, id, next);
1593 sshkey_free(id->key);
1600 pubkey_reset(Authctxt *authctxt)
1604 TAILQ_FOREACH(id, &authctxt->keys, next)
1609 try_identity(Identity *id)
1613 if (sshkey_type_plain(id->key->type) == KEY_RSA &&
1614 (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1615 debug("Skipped %s key %s for RSA/MD5 server",
1616 sshkey_type(id->key), id->filename);
1623 userauth_pubkey(Authctxt *authctxt)
1625 struct ssh *ssh = active_state; /* XXX */
1630 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1633 /* move key to the end of the queue */
1634 TAILQ_REMOVE(&authctxt->keys, id, next);
1635 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1637 * send a test message if we have the public key. for
1638 * encrypted keys we cannot do this and have to load the
1639 * private key instead
1641 if (id->key != NULL) {
1642 if (try_identity(id)) {
1643 if ((fp = sshkey_fingerprint(id->key,
1644 options.fingerprint_hash,
1645 SSH_FP_DEFAULT)) == NULL) {
1646 error("%s: sshkey_fingerprint failed",
1650 debug("Offering public key: %s %s %s",
1651 sshkey_type(id->key), fp, id->filename);
1653 sent = send_pubkey_test(ssh, authctxt, id);
1656 debug("Trying private key: %s", id->filename);
1657 id->key = load_identity_file(id);
1658 if (id->key != NULL) {
1659 if (try_identity(id)) {
1661 sent = sign_and_send_pubkey(ssh,
1664 sshkey_free(id->key);
1676 * Send userauth request message specifying keyboard-interactive method.
1679 userauth_kbdint(Authctxt *authctxt)
1681 struct ssh *ssh = active_state; /* XXX */
1682 static int attempt = 0;
1685 if (attempt++ >= options.number_of_password_prompts)
1687 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1688 if (attempt > 1 && !authctxt->info_req_seen) {
1689 debug3("userauth_kbdint: disable: no info_req_seen");
1690 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1694 debug2("userauth_kbdint");
1695 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1696 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1697 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1698 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1699 (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1700 (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1701 options.kbd_interactive_devices : "")) != 0 ||
1702 (r = sshpkt_send(ssh)) != 0)
1703 fatal("%s: %s", __func__, ssh_err(r));
1705 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1710 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1713 input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1715 Authctxt *authctxt = ssh->authctxt;
1716 char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1717 char *response = NULL;
1719 u_int num_prompts, i;
1722 debug2("input_userauth_info_req");
1724 if (authctxt == NULL)
1725 fatal("input_userauth_info_req: no authentication context");
1727 authctxt->info_req_seen = 1;
1729 if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1730 (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1731 (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1733 if (strlen(name) > 0)
1735 if (strlen(inst) > 0)
1738 if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1741 * Begin to build info response packet based on prompts requested.
1742 * We commit to providing the correct number of responses, so if
1743 * further on we run into a problem that prevents this, we have to
1744 * be sure and clean this up and send a correct error response.
1746 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1747 (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1750 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1751 for (i = 0; i < num_prompts; i++) {
1752 if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1753 (r = sshpkt_get_u8(ssh, &echo)) != 0)
1755 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1756 if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1758 freezero(response, strlen(response));
1760 response = prompt = NULL;
1762 /* done with parsing incoming message. */
1763 if ((r = sshpkt_get_end(ssh)) != 0 ||
1764 (r = sshpkt_add_padding(ssh, 64)) != 0)
1766 r = sshpkt_send(ssh);
1769 freezero(response, strlen(response));
1778 ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1779 const u_char *data, size_t datalen)
1784 int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1785 u_char rversion = 0, version = 2;
1786 void (*osigchld)(int);
1791 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1792 error("%s: not installed: %s", __func__, strerror(errno));
1795 if (fflush(stdout) != 0) {
1796 error("%s: fflush: %s", __func__, strerror(errno));
1800 error("%s: pipe: %s", __func__, strerror(errno));
1803 if (pipe(from) < 0) {
1804 error("%s: pipe: %s", __func__, strerror(errno));
1807 if ((pid = fork()) < 0) {
1808 error("%s: fork: %s", __func__, strerror(errno));
1811 osigchld = signal(SIGCHLD, SIG_DFL);
1813 /* keep the socket on exec */
1814 fcntl(sock, F_SETFD, 0);
1816 if (dup2(from[1], STDOUT_FILENO) < 0)
1817 fatal("%s: dup2: %s", __func__, strerror(errno));
1819 if (dup2(to[0], STDIN_FILENO) < 0)
1820 fatal("%s: dup2: %s", __func__, strerror(errno));
1823 /* Close everything but stdio and the socket */
1824 for (i = STDERR_FILENO + 1; i < sock; i++)
1826 closefrom(sock + 1);
1827 debug3("%s: [child] pid=%ld, exec %s",
1828 __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1829 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1830 fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1836 if ((b = sshbuf_new()) == NULL)
1837 fatal("%s: sshbuf_new failed", __func__);
1838 /* send # of sock, data to be signed */
1839 if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1840 (r = sshbuf_put_string(b, data, datalen)) != 0)
1841 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1842 if (ssh_msg_send(to[1], version, b) == -1)
1843 fatal("%s: couldn't send request", __func__);
1845 r = ssh_msg_recv(from[0], b);
1849 error("%s: no reply", __func__);
1854 while (waitpid(pid, &status, 0) < 0) {
1855 if (errno != EINTR) {
1856 error("%s: waitpid %ld: %s",
1857 __func__, (long)pid, strerror(errno));
1861 if (!WIFEXITED(status)) {
1862 error("%s: exited abnormally", __func__);
1865 if (WEXITSTATUS(status) != 0) {
1866 error("%s: exited with status %d",
1867 __func__, WEXITSTATUS(status));
1870 if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1871 error("%s: buffer error: %s", __func__, ssh_err(r));
1874 if (rversion != version) {
1875 error("%s: bad version", __func__);
1878 if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1879 error("%s: buffer error: %s", __func__, ssh_err(r));
1881 signal(SIGCHLD, osigchld);
1885 signal(SIGCHLD, osigchld);
1892 userauth_hostbased(Authctxt *authctxt)
1894 struct ssh *ssh = active_state; /* XXX */
1895 struct sshkey *private = NULL;
1896 struct sshbuf *b = NULL;
1897 u_char *sig = NULL, *keyblob = NULL;
1898 char *fp = NULL, *chost = NULL, *lname = NULL;
1899 size_t siglen = 0, keylen = 0;
1900 int i, r, success = 0;
1902 if (authctxt->ktypes == NULL) {
1903 authctxt->oktypes = xstrdup(options.hostbased_key_types);
1904 authctxt->ktypes = authctxt->oktypes;
1908 * Work through each listed type pattern in HostbasedKeyTypes,
1909 * trying each hostkey that matches the type in turn.
1912 if (authctxt->active_ktype == NULL)
1913 authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1914 if (authctxt->active_ktype == NULL ||
1915 *authctxt->active_ktype == '\0')
1917 debug3("%s: trying key type %s", __func__,
1918 authctxt->active_ktype);
1920 /* check for a useful key */
1922 for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1923 if (authctxt->sensitive->keys[i] == NULL ||
1924 authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1926 if (match_pattern_list(
1927 sshkey_ssh_name(authctxt->sensitive->keys[i]),
1928 authctxt->active_ktype, 0) != 1)
1930 /* we take and free the key */
1931 private = authctxt->sensitive->keys[i];
1932 authctxt->sensitive->keys[i] = NULL;
1936 if (private != NULL)
1938 /* No more keys of this type; advance */
1939 authctxt->active_ktype = NULL;
1941 if (private == NULL) {
1942 free(authctxt->oktypes);
1943 authctxt->oktypes = authctxt->ktypes = NULL;
1944 authctxt->active_ktype = NULL;
1945 debug("No more client hostkeys for hostbased authentication.");
1949 if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1950 SSH_FP_DEFAULT)) == NULL) {
1951 error("%s: sshkey_fingerprint failed", __func__);
1954 debug("%s: trying hostkey %s %s",
1955 __func__, sshkey_ssh_name(private), fp);
1957 /* figure out a name for the client host */
1958 if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1959 error("%s: cannot get local ipaddr/name", __func__);
1963 /* XXX sshbuf_put_stringf? */
1964 xasprintf(&chost, "%s.", lname);
1965 debug2("%s: chost %s", __func__, chost);
1967 /* construct data */
1968 if ((b = sshbuf_new()) == NULL) {
1969 error("%s: sshbuf_new failed", __func__);
1972 if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1973 error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1976 if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1977 (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1978 (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1979 (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1980 (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1981 (r = sshbuf_put_cstring(b, sshkey_ssh_name(private))) != 0 ||
1982 (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1983 (r = sshbuf_put_cstring(b, chost)) != 0 ||
1984 (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1985 error("%s: buffer error: %s", __func__, ssh_err(r));
1990 sshbuf_dump(b, stderr);
1992 r = ssh_keysign(private, &sig, &siglen,
1993 sshbuf_ptr(b), sshbuf_len(b));
1995 error("sign using hostkey %s %s failed",
1996 sshkey_ssh_name(private), fp);
1999 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2000 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2001 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2002 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
2003 (r = sshpkt_put_cstring(ssh, sshkey_ssh_name(private))) != 0 ||
2004 (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2005 (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2006 (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2007 (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2008 (r = sshpkt_send(ssh)) != 0) {
2009 error("%s: packet error: %s", __func__, ssh_err(r));
2016 freezero(sig, siglen);
2021 sshkey_free(private);
2027 /* find auth method */
2030 * given auth method name, if configurable options permit this method fill
2031 * in auth_ident field and return true, otherwise return false.
2034 authmethod_is_enabled(Authmethod *method)
2038 /* return false if options indicate this method is disabled */
2039 if (method->enabled == NULL || *method->enabled == 0)
2041 /* return false if batch mode is enabled but method needs interactive mode */
2042 if (method->batch_flag != NULL && *method->batch_flag != 0)
2048 authmethod_lookup(const char *name)
2050 Authmethod *method = NULL;
2052 for (method = authmethods; method->name != NULL; method++)
2053 if (strcmp(name, method->name) == 0)
2055 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2059 /* XXX internal state */
2060 static Authmethod *current = NULL;
2061 static char *supported = NULL;
2062 static char *preferred = NULL;
2065 * Given the authentication method list sent by the server, return the
2066 * next method we should try. If the server initially sends a nil list,
2067 * use a built-in default list.
2070 authmethod_get(char *authlist)
2075 /* Use a suitable default if we're passed a nil list. */
2076 if (authlist == NULL || strlen(authlist) == 0)
2077 authlist = options.preferred_authentications;
2079 if (supported == NULL || strcmp(authlist, supported) != 0) {
2080 debug3("start over, passed a different list %s", authlist);
2082 supported = xstrdup(authlist);
2083 preferred = options.preferred_authentications;
2084 debug3("preferred %s", preferred);
2086 } else if (current != NULL && authmethod_is_enabled(current))
2090 if ((name = match_list(preferred, supported, &next)) == NULL) {
2091 debug("No more authentication methods to try.");
2096 debug3("authmethod_lookup %s", name);
2097 debug3("remaining preferred: %s", preferred);
2098 if ((current = authmethod_lookup(name)) != NULL &&
2099 authmethod_is_enabled(current)) {
2100 debug3("authmethod_is_enabled %s", name);
2101 debug("Next authentication method: %s", name);
2110 authmethods_get(void)
2112 Authmethod *method = NULL;
2117 if ((b = sshbuf_new()) == NULL)
2118 fatal("%s: sshbuf_new failed", __func__);
2119 for (method = authmethods; method->name != NULL; method++) {
2120 if (authmethod_is_enabled(method)) {
2121 if ((r = sshbuf_putf(b, "%s%s",
2122 sshbuf_len(b) ? "," : "", method->name)) != 0)
2123 fatal("%s: buffer error: %s",
2124 __func__, ssh_err(r));
2127 if ((list = sshbuf_dup_string(b)) == NULL)
2128 fatal("%s: sshbuf_dup_string failed", __func__);