1 /* $OpenBSD: sshconnect2.c,v 1.288 2018/10/11 03:48:04 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);
585 * Format an identity for logging including filename, key type, fingerprint
586 * and location (agent, etc.). Caller must free.
589 format_identity(Identity *id)
591 char *fp = NULL, *ret = NULL;
593 if (id->key != NULL) {
594 fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
597 xasprintf(&ret, "%s %s%s%s%s%s%s",
599 id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
601 id->userprovided ? " explicit" : "",
602 (id->key && (id->key->flags & SSHKEY_FLAG_EXT)) ? " token" : "",
603 id->agent_fd != -1 ? " agent" : "");
610 input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
612 Authctxt *authctxt = ssh->authctxt;
613 struct sshkey *key = NULL;
615 int pktype, found = 0, sent = 0;
617 char *pkalg = NULL, *fp = NULL, *ident = NULL;
618 u_char *pkblob = NULL;
621 if (authctxt == NULL)
622 fatal("input_userauth_pk_ok: no authentication context");
624 if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
625 (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
626 (r = sshpkt_get_end(ssh)) != 0)
629 if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
630 debug("%s: server sent unknown pkalg %s", __func__, pkalg);
633 if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
634 debug("no key from blob. pkalg %s: %s", pkalg, ssh_err(r));
637 if (key->type != pktype) {
638 error("input_userauth_pk_ok: type mismatch "
639 "for decoded key (received %d, expected %d)",
645 * search keys in the reverse order, because last candidate has been
646 * moved to the end of the queue. this also avoids confusion by
649 TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
650 if (sshkey_equal(key, id->key)) {
655 if (!found || id == NULL) {
656 fp = sshkey_fingerprint(key, options.fingerprint_hash,
658 error("%s: server replied with unknown key: %s %s", __func__,
659 sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
662 ident = format_identity(id);
663 debug("Server accepts key: %s", ident);
664 sent = sign_and_send_pubkey(ssh, authctxt, id);
673 /* try another method if we did not send a packet */
674 if (r == 0 && sent == 0)
675 userauth(authctxt, NULL);
681 userauth_gssapi(Authctxt *authctxt)
683 struct ssh *ssh = active_state; /* XXX */
684 Gssctxt *gssctxt = NULL;
685 static gss_OID_set gss_supported = NULL;
686 static u_int mech = 0;
690 /* Try one GSSAPI method at a time, rather than sending them all at
693 if (gss_supported == NULL)
694 gss_indicate_mechs(&min, &gss_supported);
696 /* Check to see if the mechanism is usable before we offer it */
697 while (mech < gss_supported->count && !ok) {
698 /* My DER encoding requires length<128 */
699 if (gss_supported->elements[mech].length < 128 &&
700 ssh_gssapi_check_mechanism(&gssctxt,
701 &gss_supported->elements[mech], authctxt->host)) {
702 ok = 1; /* Mechanism works */
711 authctxt->methoddata=(void *)gssctxt;
713 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
714 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
715 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
716 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
717 (r = sshpkt_put_u32(ssh, 1)) != 0 ||
718 (r = sshpkt_put_u32(ssh,
719 (gss_supported->elements[mech].length) + 2)) != 0 ||
720 (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
721 (r = sshpkt_put_u8(ssh,
722 gss_supported->elements[mech].length)) != 0 ||
724 gss_supported->elements[mech].elements,
725 gss_supported->elements[mech].length)) != 0 ||
726 (r = sshpkt_send(ssh)) != 0)
727 fatal("%s: %s", __func__, ssh_err(r));
729 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
730 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
731 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
732 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
734 mech++; /* Move along to next candidate */
740 process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
742 Authctxt *authctxt = ssh->authctxt;
743 Gssctxt *gssctxt = authctxt->methoddata;
744 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
745 gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
746 gss_buffer_desc gssbuf;
747 OM_uint32 status, ms, flags;
750 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
751 recv_tok, &send_tok, &flags);
753 if (send_tok.length > 0) {
754 u_char type = GSS_ERROR(status) ?
755 SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
756 SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
758 if ((r = sshpkt_start(ssh, type)) != 0 ||
759 (r = sshpkt_put_string(ssh, send_tok.value,
760 send_tok.length)) != 0 ||
761 (r = sshpkt_send(ssh)) != 0)
762 fatal("%s: %s", __func__, ssh_err(r));
764 gss_release_buffer(&ms, &send_tok);
767 if (status == GSS_S_COMPLETE) {
768 /* send either complete or MIC, depending on mechanism */
769 if (!(flags & GSS_C_INTEG_FLAG)) {
770 if ((r = sshpkt_start(ssh,
771 SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
772 (r = sshpkt_send(ssh)) != 0)
773 fatal("%s: %s", __func__, ssh_err(r));
777 if ((b = sshbuf_new()) == NULL)
778 fatal("%s: sshbuf_new failed", __func__);
779 ssh_gssapi_buildmic(b, authctxt->server_user,
780 authctxt->service, "gssapi-with-mic");
782 if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
783 fatal("%s: sshbuf_mutable_ptr failed", __func__);
784 gssbuf.length = sshbuf_len(b);
786 status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
788 if (!GSS_ERROR(status)) {
789 if ((r = sshpkt_start(ssh,
790 SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
791 (r = sshpkt_put_string(ssh, mic.value,
793 (r = sshpkt_send(ssh)) != 0)
794 fatal("%s: %s", __func__, ssh_err(r));
798 gss_release_buffer(&ms, &mic);
807 input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
809 Authctxt *authctxt = ssh->authctxt;
815 if (authctxt == NULL)
816 fatal("input_gssapi_response: no authentication context");
817 gssctxt = authctxt->methoddata;
820 if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
824 oidv[0] != SSH_GSS_OIDTYPE ||
825 oidv[1] != oidlen - 2) {
826 debug("Badly encoded mechanism OID received");
827 userauth(authctxt, NULL);
831 if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
832 fatal("Server returned different OID than expected");
834 if ((r = sshpkt_get_end(ssh)) != 0)
837 if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
838 /* Start again with next method on list */
839 debug("Trying to start again");
840 userauth(authctxt, NULL);
852 input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
854 Authctxt *authctxt = ssh->authctxt;
855 gss_buffer_desc recv_tok;
861 if (authctxt == NULL)
862 fatal("input_gssapi_response: no authentication context");
864 if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
865 (r = sshpkt_get_end(ssh)) != 0)
869 recv_tok.length = len;
870 status = process_gssapi_token(ssh, &recv_tok);
872 /* Start again with the next method in the list */
873 if (GSS_ERROR(status)) {
874 userauth(authctxt, NULL);
885 input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
887 Authctxt *authctxt = ssh->authctxt;
889 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
890 gss_buffer_desc recv_tok;
896 if (authctxt == NULL)
897 fatal("input_gssapi_response: no authentication context");
898 gssctxt = authctxt->methoddata;
900 if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
901 (r = sshpkt_get_end(ssh)) != 0) {
906 /* Stick it into GSSAPI and see what it says */
908 recv_tok.length = len;
909 (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
910 &recv_tok, &send_tok, NULL);
912 gss_release_buffer(&ms, &send_tok);
914 /* Server will be returning a failed packet after this one */
920 input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
926 if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
927 (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
928 (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
929 (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
931 r = sshpkt_get_end(ssh);
932 debug("Server GSSAPI Error:\n%s", msg);
941 userauth_none(Authctxt *authctxt)
943 struct ssh *ssh = active_state; /* XXX */
946 /* initial userauth request */
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_send(ssh)) != 0)
952 fatal("%s: %s", __func__, ssh_err(r));
957 userauth_passwd(Authctxt *authctxt)
959 struct ssh *ssh = active_state; /* XXX */
960 static int attempt = 0;
963 const char *host = options.host_key_alias ? options.host_key_alias :
967 if (attempt++ >= options.number_of_password_prompts)
971 error("Permission denied, please try again.");
973 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
974 authctxt->server_user, host);
975 password = read_passphrase(prompt, 0);
976 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
977 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
978 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
979 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
980 (r = sshpkt_put_u8(ssh, 0)) != 0 ||
981 (r = sshpkt_put_cstring(ssh, password)) != 0 ||
982 (r = sshpkt_add_padding(ssh, 64)) != 0 ||
983 (r = sshpkt_send(ssh)) != 0)
984 fatal("%s: %s", __func__, ssh_err(r));
987 freezero(password, strlen(password));
989 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
990 &input_userauth_passwd_changereq);
996 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
1000 input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1002 Authctxt *authctxt = ssh->authctxt;
1003 char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1008 debug2("input_userauth_passwd_changereq");
1010 if (authctxt == NULL)
1011 fatal("input_userauth_passwd_changereq: "
1012 "no authentication context");
1013 host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1015 if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
1016 (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1018 if (strlen(info) > 0)
1020 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1021 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1022 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1023 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1024 (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
1027 snprintf(prompt, sizeof(prompt),
1028 "Enter %.30s@%.128s's old password: ",
1029 authctxt->server_user, host);
1030 password = read_passphrase(prompt, 0);
1031 if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1034 freezero(password, strlen(password));
1036 while (password == NULL) {
1037 snprintf(prompt, sizeof(prompt),
1038 "Enter %.30s@%.128s's new password: ",
1039 authctxt->server_user, host);
1040 password = read_passphrase(prompt, RP_ALLOW_EOF);
1041 if (password == NULL) {
1046 snprintf(prompt, sizeof(prompt),
1047 "Retype %.30s@%.128s's new password: ",
1048 authctxt->server_user, host);
1049 retype = read_passphrase(prompt, 0);
1050 if (strcmp(password, retype) != 0) {
1051 freezero(password, strlen(password));
1052 logit("Mismatch; try again, EOF to quit.");
1055 freezero(retype, strlen(retype));
1057 if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1058 (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1059 (r = sshpkt_send(ssh)) != 0)
1062 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1063 &input_userauth_passwd_changereq);
1067 freezero(password, strlen(password));
1074 * Select an algorithm for publickey signatures.
1075 * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1077 * Call with ssh==NULL to ignore server-sig-algs extension list and
1078 * only attempt with the key's base signature type.
1081 key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1083 char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1086 * The signature algorithm will only differ from the key algorithm
1087 * for RSA keys/certs and when the server advertises support for
1088 * newer (SHA2) algorithms.
1090 if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1091 (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
1092 (key->type == KEY_RSA_CERT && (datafellows & SSH_BUG_SIGTYPE))) {
1093 /* Filter base key signature alg against our configuration */
1094 return match_list(sshkey_ssh_name(key),
1095 options.pubkey_key_types, NULL);
1099 * For RSA keys/certs, since these might have a different sig type:
1100 * find the first entry in PubkeyAcceptedKeyTypes of the right type
1101 * that also appears in the supported signature algorithms list from
1104 oallowed = allowed = xstrdup(options.pubkey_key_types);
1105 while ((cp = strsep(&allowed, ",")) != NULL) {
1106 if (sshkey_type_from_name(cp) != key->type)
1108 tmp = match_list(sshkey_sigalg_by_name(cp), ssh->kex->server_sig_algs, NULL);
1120 identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1121 const u_char *data, size_t datalen, u_int compat, const char *alg)
1126 /* The agent supports this key. */
1127 if (id->key != NULL && id->agent_fd != -1) {
1128 return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1129 data, datalen, alg, compat);
1133 * We have already loaded the private key or the private key is
1134 * stored in external hardware.
1136 if (id->key != NULL &&
1137 (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1138 if ((r = sshkey_sign(id->key, sigp, lenp, data, datalen,
1142 * PKCS#11 tokens may not support all signature algorithms,
1143 * so check what we get back.
1145 if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0)
1150 /* Load the private key from the file. */
1151 if ((prv = load_identity_file(id)) == NULL)
1152 return SSH_ERR_KEY_NOT_FOUND;
1153 if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1154 error("%s: private key %s contents do not match public",
1155 __func__, id->filename);
1156 return SSH_ERR_KEY_NOT_FOUND;
1158 r = sshkey_sign(prv, sigp, lenp, data, datalen, alg, compat);
1164 id_filename_matches(Identity *id, Identity *private_id)
1166 const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1167 size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1170 if (strcmp(id->filename, private_id->filename) == 0)
1172 for (i = 0; suffixes[i]; i++) {
1173 slen = strlen(suffixes[i]);
1174 if (len > slen && plen == len - slen &&
1175 strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1176 memcmp(id->filename, private_id->filename, plen) == 0)
1183 sign_and_send_pubkey(struct ssh *ssh, Authctxt *authctxt, Identity *id)
1185 struct sshbuf *b = NULL;
1186 Identity *private_id, *sign_id = NULL;
1187 u_char *signature = NULL;
1188 size_t slen = 0, skip = 0;
1189 int r, fallback_sigtype, sent = 0;
1190 char *alg = NULL, *fp = NULL;
1191 const char *loc = "";
1193 if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1194 SSH_FP_DEFAULT)) == NULL)
1197 debug3("%s: %s %s", __func__, sshkey_type(id->key), fp);
1200 * If the key is an certificate, try to find a matching private key
1201 * and use it to complete the signature.
1202 * If no such private key exists, fall back to trying the certificate
1203 * key itself in case it has a private half already loaded.
1204 * This will try to set sign_id to the private key that will perform
1207 if (sshkey_is_cert(id->key)) {
1208 TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1209 if (sshkey_equal_public(id->key, private_id->key) &&
1210 id->key->type != private_id->key->type) {
1211 sign_id = private_id;
1216 * Exact key matches are preferred, but also allow
1217 * filename matches for non-PKCS#11/agent keys that
1218 * didn't load public keys. This supports the case
1219 * of keeping just a private key file and public
1220 * certificate on disk.
1222 if (sign_id == NULL &&
1223 !id->isprivate && id->agent_fd == -1 &&
1224 (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1225 TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1226 if (private_id->key == NULL &&
1227 id_filename_matches(id, private_id)) {
1228 sign_id = private_id;
1233 if (sign_id != NULL) {
1234 debug2("%s: using private key \"%s\"%s for "
1235 "certificate", __func__, id->filename,
1236 id->agent_fd != -1 ? " from agent" : "");
1238 debug("%s: no separate private key for certificate "
1239 "\"%s\"", __func__, id->filename);
1244 * If the above didn't select another identity to do the signing
1245 * then default to the one we started with.
1247 if (sign_id == NULL)
1250 /* assemble and sign data */
1251 for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1255 if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1256 id->key)) == NULL) {
1257 error("%s: no mutual signature supported", __func__);
1260 debug3("%s: signing using %s", __func__, alg);
1263 if ((b = sshbuf_new()) == NULL)
1264 fatal("%s: sshbuf_new failed", __func__);
1265 if (datafellows & SSH_OLD_SESSIONID) {
1266 if ((r = sshbuf_put(b, session_id2,
1267 session_id2_len)) != 0) {
1268 fatal("%s: sshbuf_put: %s",
1269 __func__, ssh_err(r));
1272 if ((r = sshbuf_put_string(b, session_id2,
1273 session_id2_len)) != 0) {
1274 fatal("%s: sshbuf_put_string: %s",
1275 __func__, ssh_err(r));
1278 skip = sshbuf_len(b);
1279 if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1280 (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1281 (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1282 (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1283 (r = sshbuf_put_u8(b, 1)) != 0 ||
1284 (r = sshbuf_put_cstring(b, alg)) != 0 ||
1285 (r = sshkey_puts(id->key, b)) != 0) {
1286 fatal("%s: assemble signed data: %s",
1287 __func__, ssh_err(r));
1290 /* generate signature */
1291 r = identity_sign(sign_id, &signature, &slen,
1292 sshbuf_ptr(b), sshbuf_len(b), datafellows, alg);
1295 else if (r == SSH_ERR_KEY_NOT_FOUND)
1296 goto out; /* soft failure */
1297 else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1298 !fallback_sigtype) {
1299 if (sign_id->agent_fd != -1)
1301 else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1303 logit("%skey %s %s returned incorrect signature type",
1304 loc, sshkey_type(id->key), fp);
1307 error("%s: signing failed: %s", __func__, ssh_err(r));
1310 if (slen == 0 || signature == NULL) /* shouldn't happen */
1311 fatal("%s: no signature", __func__);
1313 /* append signature */
1314 if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1315 fatal("%s: append signature: %s", __func__, ssh_err(r));
1318 sshbuf_dump(b, stderr);
1320 /* skip session id and packet type */
1321 if ((r = sshbuf_consume(b, skip + 1)) != 0)
1322 fatal("%s: consume: %s", __func__, ssh_err(r));
1324 /* put remaining data from buffer into packet */
1325 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1326 (r = sshpkt_putb(ssh, b)) != 0 ||
1327 (r = sshpkt_send(ssh)) != 0)
1328 fatal("%s: enqueue request: %s", __func__, ssh_err(r));
1337 freezero(signature, slen);
1342 send_pubkey_test(struct ssh *ssh, Authctxt *authctxt, Identity *id)
1344 u_char *blob = NULL;
1350 if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1351 debug("%s: no mutual signature algorithm", __func__);
1355 if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1356 /* we cannot handle this key */
1357 debug3("%s: cannot handle key", __func__);
1360 /* register callback for USERAUTH_PK_OK message */
1361 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1363 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1364 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1365 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1366 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1367 (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1368 (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1369 (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1370 (r = sshpkt_send(ssh)) != 0)
1371 fatal("%s: %s", __func__, ssh_err(r));
1380 static struct sshkey *
1381 load_identity_file(Identity *id)
1383 struct sshkey *private = NULL;
1384 char prompt[300], *passphrase, *comment;
1385 int r, perm_ok = 0, quit = 0, i;
1388 if (stat(id->filename, &st) < 0) {
1389 (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1390 id->filename, strerror(errno));
1393 snprintf(prompt, sizeof prompt,
1394 "Enter passphrase for key '%.100s': ", id->filename);
1395 for (i = 0; i <= options.number_of_password_prompts; i++) {
1399 passphrase = read_passphrase(prompt, 0);
1400 if (*passphrase == '\0') {
1401 debug2("no passphrase given, try next key");
1406 switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1407 passphrase, &private, &comment, &perm_ok))) {
1410 case SSH_ERR_KEY_WRONG_PASSPHRASE:
1411 if (options.batch_mode) {
1416 debug2("bad passphrase given, try again...");
1418 case SSH_ERR_SYSTEM_ERROR:
1419 if (errno == ENOENT) {
1420 debug2("Load key \"%s\": %s",
1421 id->filename, ssh_err(r));
1427 error("Load key \"%s\": %s", id->filename, ssh_err(r));
1431 if (!quit && private != NULL && id->agent_fd == -1 &&
1432 !(id->key && id->isprivate))
1433 maybe_add_key_to_agent(id->filename, private, comment,
1436 freezero(passphrase, strlen(passphrase));
1438 if (private != NULL || quit)
1445 key_type_allowed_by_config(struct sshkey *key)
1447 if (match_pattern_list(sshkey_ssh_name(key),
1448 options.pubkey_key_types, 0) == 1)
1451 /* RSA keys/certs might be allowed by alternate signature types */
1452 switch (key->type) {
1454 if (match_pattern_list("rsa-sha2-512",
1455 options.pubkey_key_types, 0) == 1)
1457 if (match_pattern_list("rsa-sha2-256",
1458 options.pubkey_key_types, 0) == 1)
1462 if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1463 options.pubkey_key_types, 0) == 1)
1465 if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1466 options.pubkey_key_types, 0) == 1)
1475 * try keys in the following order:
1476 * 1. certificates listed in the config file
1477 * 2. other input certificates
1478 * 3. agent keys that are found in the config file
1479 * 4. other agent keys
1480 * 5. keys that are only listed in the config file
1483 pubkey_prepare(Authctxt *authctxt)
1485 struct identity *id, *id2, *tmp;
1486 struct idlist agent, files, *preferred;
1488 int agent_fd = -1, i, r, found;
1490 struct ssh_identitylist *idlist;
1493 TAILQ_INIT(&agent); /* keys from the agent */
1494 TAILQ_INIT(&files); /* keys from the config file */
1495 preferred = &authctxt->keys;
1496 TAILQ_INIT(preferred); /* preferred order of keys */
1498 /* list of keys stored in the filesystem and PKCS#11 */
1499 for (i = 0; i < options.num_identity_files; i++) {
1500 key = options.identity_keys[i];
1501 if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1503 options.identity_keys[i] = NULL;
1504 id = xcalloc(1, sizeof(*id));
1507 id->filename = xstrdup(options.identity_files[i]);
1508 id->userprovided = options.identity_file_userprovided[i];
1509 TAILQ_INSERT_TAIL(&files, id, next);
1511 /* list of certificates specified by user */
1512 for (i = 0; i < options.num_certificate_files; i++) {
1513 key = options.certificates[i];
1514 if (!sshkey_is_cert(key) || key->cert == NULL ||
1515 key->cert->type != SSH2_CERT_TYPE_USER)
1517 id = xcalloc(1, sizeof(*id));
1520 id->filename = xstrdup(options.certificate_files[i]);
1521 id->userprovided = options.certificate_file_userprovided[i];
1522 TAILQ_INSERT_TAIL(preferred, id, next);
1524 /* list of keys supported by the agent */
1525 if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1526 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1527 debug("%s: ssh_get_authentication_socket: %s",
1528 __func__, ssh_err(r));
1529 } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1530 if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1531 debug("%s: ssh_fetch_identitylist: %s",
1532 __func__, ssh_err(r));
1535 for (j = 0; j < idlist->nkeys; j++) {
1537 TAILQ_FOREACH(id, &files, next) {
1539 * agent keys from the config file are
1542 if (sshkey_equal(idlist->keys[j], id->key)) {
1543 TAILQ_REMOVE(&files, id, next);
1544 TAILQ_INSERT_TAIL(preferred, id, next);
1545 id->agent_fd = agent_fd;
1550 if (!found && !options.identities_only) {
1551 id = xcalloc(1, sizeof(*id));
1552 /* XXX "steals" key/comment from idlist */
1553 id->key = idlist->keys[j];
1554 id->filename = idlist->comments[j];
1555 idlist->keys[j] = NULL;
1556 idlist->comments[j] = NULL;
1557 id->agent_fd = agent_fd;
1558 TAILQ_INSERT_TAIL(&agent, id, next);
1561 ssh_free_identitylist(idlist);
1562 /* append remaining agent keys */
1563 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1564 TAILQ_REMOVE(&agent, id, next);
1565 TAILQ_INSERT_TAIL(preferred, id, next);
1567 authctxt->agent_fd = agent_fd;
1569 /* Prefer PKCS11 keys that are explicitly listed */
1570 TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1571 if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1574 TAILQ_FOREACH(id2, &files, next) {
1575 if (id2->key == NULL ||
1576 (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1578 if (sshkey_equal(id->key, id2->key)) {
1579 TAILQ_REMOVE(&files, id, next);
1580 TAILQ_INSERT_TAIL(preferred, id, next);
1585 /* If IdentitiesOnly set and key not found then don't use it */
1586 if (!found && options.identities_only) {
1587 TAILQ_REMOVE(&files, id, next);
1588 freezero(id, sizeof(*id));
1591 /* append remaining keys from the config file */
1592 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1593 TAILQ_REMOVE(&files, id, next);
1594 TAILQ_INSERT_TAIL(preferred, id, next);
1596 /* finally, filter by PubkeyAcceptedKeyTypes */
1597 TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1598 if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1599 debug("Skipping %s key %s - "
1600 "not in PubkeyAcceptedKeyTypes",
1601 sshkey_ssh_name(id->key), id->filename);
1602 TAILQ_REMOVE(preferred, id, next);
1603 sshkey_free(id->key);
1605 memset(id, 0, sizeof(*id));
1609 /* List the keys we plan on using */
1610 TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1611 ident = format_identity(id);
1612 debug("Will attempt key: %s", ident);
1615 debug2("%s: done", __func__);
1619 pubkey_cleanup(Authctxt *authctxt)
1623 if (authctxt->agent_fd != -1)
1624 ssh_close_authentication_socket(authctxt->agent_fd);
1625 for (id = TAILQ_FIRST(&authctxt->keys); id;
1626 id = TAILQ_FIRST(&authctxt->keys)) {
1627 TAILQ_REMOVE(&authctxt->keys, id, next);
1628 sshkey_free(id->key);
1635 pubkey_reset(Authctxt *authctxt)
1639 TAILQ_FOREACH(id, &authctxt->keys, next)
1644 try_identity(Identity *id)
1648 if (sshkey_type_plain(id->key->type) == KEY_RSA &&
1649 (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1650 debug("Skipped %s key %s for RSA/MD5 server",
1651 sshkey_type(id->key), id->filename);
1658 userauth_pubkey(Authctxt *authctxt)
1660 struct ssh *ssh = active_state; /* XXX */
1665 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1668 /* move key to the end of the queue */
1669 TAILQ_REMOVE(&authctxt->keys, id, next);
1670 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1672 * send a test message if we have the public key. for
1673 * encrypted keys we cannot do this and have to load the
1674 * private key instead
1676 if (id->key != NULL) {
1677 if (try_identity(id)) {
1678 ident = format_identity(id);
1679 debug("Offering public key: %s", ident);
1681 sent = send_pubkey_test(ssh, authctxt, id);
1684 debug("Trying private key: %s", id->filename);
1685 id->key = load_identity_file(id);
1686 if (id->key != NULL) {
1687 if (try_identity(id)) {
1689 sent = sign_and_send_pubkey(ssh,
1692 sshkey_free(id->key);
1704 * Send userauth request message specifying keyboard-interactive method.
1707 userauth_kbdint(Authctxt *authctxt)
1709 struct ssh *ssh = active_state; /* XXX */
1710 static int attempt = 0;
1713 if (attempt++ >= options.number_of_password_prompts)
1715 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1716 if (attempt > 1 && !authctxt->info_req_seen) {
1717 debug3("userauth_kbdint: disable: no info_req_seen");
1718 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1722 debug2("userauth_kbdint");
1723 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1724 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1725 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1726 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1727 (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1728 (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1729 options.kbd_interactive_devices : "")) != 0 ||
1730 (r = sshpkt_send(ssh)) != 0)
1731 fatal("%s: %s", __func__, ssh_err(r));
1733 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1738 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1741 input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1743 Authctxt *authctxt = ssh->authctxt;
1744 char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1745 char *response = NULL;
1747 u_int num_prompts, i;
1750 debug2("input_userauth_info_req");
1752 if (authctxt == NULL)
1753 fatal("input_userauth_info_req: no authentication context");
1755 authctxt->info_req_seen = 1;
1757 if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1758 (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1759 (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1761 if (strlen(name) > 0)
1763 if (strlen(inst) > 0)
1766 if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1769 * Begin to build info response packet based on prompts requested.
1770 * We commit to providing the correct number of responses, so if
1771 * further on we run into a problem that prevents this, we have to
1772 * be sure and clean this up and send a correct error response.
1774 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1775 (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1778 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1779 for (i = 0; i < num_prompts; i++) {
1780 if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1781 (r = sshpkt_get_u8(ssh, &echo)) != 0)
1783 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1784 if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1786 freezero(response, strlen(response));
1788 response = prompt = NULL;
1790 /* done with parsing incoming message. */
1791 if ((r = sshpkt_get_end(ssh)) != 0 ||
1792 (r = sshpkt_add_padding(ssh, 64)) != 0)
1794 r = sshpkt_send(ssh);
1797 freezero(response, strlen(response));
1806 ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1807 const u_char *data, size_t datalen)
1812 int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1813 u_char rversion = 0, version = 2;
1814 void (*osigchld)(int);
1819 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1820 error("%s: not installed: %s", __func__, strerror(errno));
1823 if (fflush(stdout) != 0) {
1824 error("%s: fflush: %s", __func__, strerror(errno));
1828 error("%s: pipe: %s", __func__, strerror(errno));
1831 if (pipe(from) < 0) {
1832 error("%s: pipe: %s", __func__, strerror(errno));
1835 if ((pid = fork()) < 0) {
1836 error("%s: fork: %s", __func__, strerror(errno));
1839 osigchld = signal(SIGCHLD, SIG_DFL);
1841 /* keep the socket on exec */
1842 fcntl(sock, F_SETFD, 0);
1844 if (dup2(from[1], STDOUT_FILENO) < 0)
1845 fatal("%s: dup2: %s", __func__, strerror(errno));
1847 if (dup2(to[0], STDIN_FILENO) < 0)
1848 fatal("%s: dup2: %s", __func__, strerror(errno));
1851 /* Close everything but stdio and the socket */
1852 for (i = STDERR_FILENO + 1; i < sock; i++)
1854 closefrom(sock + 1);
1855 debug3("%s: [child] pid=%ld, exec %s",
1856 __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1857 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1858 fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1864 if ((b = sshbuf_new()) == NULL)
1865 fatal("%s: sshbuf_new failed", __func__);
1866 /* send # of sock, data to be signed */
1867 if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1868 (r = sshbuf_put_string(b, data, datalen)) != 0)
1869 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1870 if (ssh_msg_send(to[1], version, b) == -1)
1871 fatal("%s: couldn't send request", __func__);
1873 r = ssh_msg_recv(from[0], b);
1877 error("%s: no reply", __func__);
1882 while (waitpid(pid, &status, 0) < 0) {
1883 if (errno != EINTR) {
1884 error("%s: waitpid %ld: %s",
1885 __func__, (long)pid, strerror(errno));
1889 if (!WIFEXITED(status)) {
1890 error("%s: exited abnormally", __func__);
1893 if (WEXITSTATUS(status) != 0) {
1894 error("%s: exited with status %d",
1895 __func__, WEXITSTATUS(status));
1898 if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1899 error("%s: buffer error: %s", __func__, ssh_err(r));
1902 if (rversion != version) {
1903 error("%s: bad version", __func__);
1906 if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1907 error("%s: buffer error: %s", __func__, ssh_err(r));
1909 signal(SIGCHLD, osigchld);
1913 signal(SIGCHLD, osigchld);
1920 userauth_hostbased(Authctxt *authctxt)
1922 struct ssh *ssh = active_state; /* XXX */
1923 struct sshkey *private = NULL;
1924 struct sshbuf *b = NULL;
1925 u_char *sig = NULL, *keyblob = NULL;
1926 char *fp = NULL, *chost = NULL, *lname = NULL;
1927 size_t siglen = 0, keylen = 0;
1928 int i, r, success = 0;
1930 if (authctxt->ktypes == NULL) {
1931 authctxt->oktypes = xstrdup(options.hostbased_key_types);
1932 authctxt->ktypes = authctxt->oktypes;
1936 * Work through each listed type pattern in HostbasedKeyTypes,
1937 * trying each hostkey that matches the type in turn.
1940 if (authctxt->active_ktype == NULL)
1941 authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1942 if (authctxt->active_ktype == NULL ||
1943 *authctxt->active_ktype == '\0')
1945 debug3("%s: trying key type %s", __func__,
1946 authctxt->active_ktype);
1948 /* check for a useful key */
1950 for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1951 if (authctxt->sensitive->keys[i] == NULL ||
1952 authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1954 if (match_pattern_list(
1955 sshkey_ssh_name(authctxt->sensitive->keys[i]),
1956 authctxt->active_ktype, 0) != 1)
1958 /* we take and free the key */
1959 private = authctxt->sensitive->keys[i];
1960 authctxt->sensitive->keys[i] = NULL;
1964 if (private != NULL)
1966 /* No more keys of this type; advance */
1967 authctxt->active_ktype = NULL;
1969 if (private == NULL) {
1970 free(authctxt->oktypes);
1971 authctxt->oktypes = authctxt->ktypes = NULL;
1972 authctxt->active_ktype = NULL;
1973 debug("No more client hostkeys for hostbased authentication.");
1977 if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1978 SSH_FP_DEFAULT)) == NULL) {
1979 error("%s: sshkey_fingerprint failed", __func__);
1982 debug("%s: trying hostkey %s %s",
1983 __func__, sshkey_ssh_name(private), fp);
1985 /* figure out a name for the client host */
1986 if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1987 error("%s: cannot get local ipaddr/name", __func__);
1991 /* XXX sshbuf_put_stringf? */
1992 xasprintf(&chost, "%s.", lname);
1993 debug2("%s: chost %s", __func__, chost);
1995 /* construct data */
1996 if ((b = sshbuf_new()) == NULL) {
1997 error("%s: sshbuf_new failed", __func__);
2000 if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
2001 error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
2004 if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
2005 (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2006 (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
2007 (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
2008 (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
2009 (r = sshbuf_put_cstring(b, sshkey_ssh_name(private))) != 0 ||
2010 (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
2011 (r = sshbuf_put_cstring(b, chost)) != 0 ||
2012 (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
2013 error("%s: buffer error: %s", __func__, ssh_err(r));
2018 sshbuf_dump(b, stderr);
2020 r = ssh_keysign(private, &sig, &siglen,
2021 sshbuf_ptr(b), sshbuf_len(b));
2023 error("sign using hostkey %s %s failed",
2024 sshkey_ssh_name(private), fp);
2027 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2028 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2029 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2030 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
2031 (r = sshpkt_put_cstring(ssh, sshkey_ssh_name(private))) != 0 ||
2032 (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2033 (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2034 (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2035 (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2036 (r = sshpkt_send(ssh)) != 0) {
2037 error("%s: packet error: %s", __func__, ssh_err(r));
2044 freezero(sig, siglen);
2049 sshkey_free(private);
2055 /* find auth method */
2058 * given auth method name, if configurable options permit this method fill
2059 * in auth_ident field and return true, otherwise return false.
2062 authmethod_is_enabled(Authmethod *method)
2066 /* return false if options indicate this method is disabled */
2067 if (method->enabled == NULL || *method->enabled == 0)
2069 /* return false if batch mode is enabled but method needs interactive mode */
2070 if (method->batch_flag != NULL && *method->batch_flag != 0)
2076 authmethod_lookup(const char *name)
2078 Authmethod *method = NULL;
2080 for (method = authmethods; method->name != NULL; method++)
2081 if (strcmp(name, method->name) == 0)
2083 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2087 /* XXX internal state */
2088 static Authmethod *current = NULL;
2089 static char *supported = NULL;
2090 static char *preferred = NULL;
2093 * Given the authentication method list sent by the server, return the
2094 * next method we should try. If the server initially sends a nil list,
2095 * use a built-in default list.
2098 authmethod_get(char *authlist)
2103 /* Use a suitable default if we're passed a nil list. */
2104 if (authlist == NULL || strlen(authlist) == 0)
2105 authlist = options.preferred_authentications;
2107 if (supported == NULL || strcmp(authlist, supported) != 0) {
2108 debug3("start over, passed a different list %s", authlist);
2110 supported = xstrdup(authlist);
2111 preferred = options.preferred_authentications;
2112 debug3("preferred %s", preferred);
2114 } else if (current != NULL && authmethod_is_enabled(current))
2118 if ((name = match_list(preferred, supported, &next)) == NULL) {
2119 debug("No more authentication methods to try.");
2124 debug3("authmethod_lookup %s", name);
2125 debug3("remaining preferred: %s", preferred);
2126 if ((current = authmethod_lookup(name)) != NULL &&
2127 authmethod_is_enabled(current)) {
2128 debug3("authmethod_is_enabled %s", name);
2129 debug("Next authentication method: %s", name);
2138 authmethods_get(void)
2140 Authmethod *method = NULL;
2145 if ((b = sshbuf_new()) == NULL)
2146 fatal("%s: sshbuf_new failed", __func__);
2147 for (method = authmethods; method->name != NULL; method++) {
2148 if (authmethod_is_enabled(method)) {
2149 if ((r = sshbuf_putf(b, "%s%s",
2150 sshbuf_len(b) ? "," : "", method->name)) != 0)
2151 fatal("%s: buffer error: %s",
2152 __func__, ssh_err(r));
2155 if ((list = sshbuf_dup_string(b)) == NULL)
2156 fatal("%s: sshbuf_dup_string failed", __func__);