1 /* $OpenBSD: sshconnect2.c,v 1.223 2015/01/30 11:43:14 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"
80 extern char *client_version_string;
81 extern char *server_version_string;
82 extern Options options;
88 u_char *session_id2 = NULL;
89 u_int session_id2_len = 0;
92 struct sockaddr *xxx_hostaddr;
95 verify_host_key_callback(Key *hostkey, struct ssh *ssh)
97 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
98 fatal("Host key verification failed.");
103 order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
105 char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
107 struct hostkeys *hostkeys;
111 /* Find all hostkeys for this hostname */
112 get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
113 hostkeys = init_hostkeys();
114 for (i = 0; i < options.num_user_hostfiles; i++)
115 load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
116 for (i = 0; i < options.num_system_hostfiles; i++)
117 load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
119 oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
120 maxlen = strlen(avail) + 1;
121 first = xmalloc(maxlen);
122 last = xmalloc(maxlen);
123 *first = *last = '\0';
125 #define ALG_APPEND(to, from) \
128 strlcat(to, ",", maxlen); \
129 strlcat(to, from, maxlen); \
132 while ((alg = strsep(&avail, ",")) && *alg != '\0') {
133 if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
134 fatal("%s: unknown alg %s", __func__, alg);
135 if (lookup_key_in_hostkeys_by_type(hostkeys,
136 sshkey_type_plain(ktype), NULL))
137 ALG_APPEND(first, alg);
139 ALG_APPEND(last, alg);
142 xasprintf(&ret, "%s%s%s", first,
143 (*first == '\0' || *last == '\0') ? "" : ",", last);
145 debug3("%s: prefer hostkeyalgs: %s", __func__, first);
151 free_hostkeys(hostkeys);
157 ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
159 char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
164 xxx_hostaddr = hostaddr;
166 if (options.ciphers == (char *)-1) {
167 logit("No valid ciphers for protocol version 2 given, using defaults.");
168 options.ciphers = NULL;
170 if (options.ciphers != NULL) {
171 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
172 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
174 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
175 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
176 myproposal[PROPOSAL_ENC_ALGS_STOC] =
177 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
178 if (options.compression) {
179 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
180 myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
182 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
183 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
185 if (options.macs != NULL) {
186 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
187 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
189 if (options.hostkeyalgorithms != NULL)
190 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
191 compat_pkalg_proposal(options.hostkeyalgorithms);
193 /* Prefer algorithms that we already have keys for */
194 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
195 compat_pkalg_proposal(
196 order_hostkeyalgs(host, hostaddr, port));
198 if (options.kex_algorithms != NULL)
199 myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
200 myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(
201 myproposal[PROPOSAL_KEX_ALGS]);
203 if (options.rekey_limit || options.rekey_interval)
204 packet_set_rekey_limits((u_int32_t)options.rekey_limit,
205 (time_t)options.rekey_interval);
207 /* start key exchange */
208 if ((r = kex_setup(active_state, myproposal)) != 0)
209 fatal("kex_setup: %s", ssh_err(r));
210 kex = active_state->kex;
212 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
213 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
214 kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
215 kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
216 # ifdef OPENSSL_HAS_ECC
217 kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
220 kex->kex[KEX_C25519_SHA256] = kexc25519_client;
221 kex->client_version_string=client_version_string;
222 kex->server_version_string=server_version_string;
223 kex->verify_host_key=&verify_host_key_callback;
225 dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
227 if (options.use_roaming && !kex->roaming) {
228 debug("Roaming not allowed by server");
229 options.use_roaming = 0;
232 session_id2 = kex->session_id;
233 session_id2_len = kex->session_id_len;
236 /* send 1st encrypted/maced/compressed message */
237 packet_start(SSH2_MSG_IGNORE);
238 packet_put_cstring("markus");
248 typedef struct cauthctxt Authctxt;
249 typedef struct cauthmethod Authmethod;
250 typedef struct identity Identity;
251 typedef struct idlist Idlist;
254 TAILQ_ENTRY(identity) next;
255 int agent_fd; /* >=0 if agent supports key */
256 struct sshkey *key; /* public/private key */
257 char *filename; /* comment for agent-only keys */
259 int isprivate; /* key points to the private key */
262 TAILQ_HEAD(idlist, identity);
265 const char *server_user;
266 const char *local_user;
269 struct cauthmethod *method;
270 sig_atomic_t success;
277 Sensitive *sensitive;
278 char *oktypes, *ktypes;
279 const char *active_ktype;
280 /* kbd-interactive */
287 char *name; /* string to compare against server's list */
288 int (*userauth)(Authctxt *authctxt);
289 void (*cleanup)(Authctxt *authctxt);
290 int *enabled; /* flag in option struct that enables method */
291 int *batch_flag; /* flag in option struct that disables method */
294 int input_userauth_success(int, u_int32_t, void *);
295 int input_userauth_success_unexpected(int, u_int32_t, void *);
296 int input_userauth_failure(int, u_int32_t, void *);
297 int input_userauth_banner(int, u_int32_t, void *);
298 int input_userauth_error(int, u_int32_t, void *);
299 int input_userauth_info_req(int, u_int32_t, void *);
300 int input_userauth_pk_ok(int, u_int32_t, void *);
301 int input_userauth_passwd_changereq(int, u_int32_t, void *);
303 int userauth_none(Authctxt *);
304 int userauth_pubkey(Authctxt *);
305 int userauth_passwd(Authctxt *);
306 int userauth_kbdint(Authctxt *);
307 int userauth_hostbased(Authctxt *);
310 int userauth_gssapi(Authctxt *authctxt);
311 int input_gssapi_response(int type, u_int32_t, void *);
312 int input_gssapi_token(int type, u_int32_t, void *);
313 int input_gssapi_hash(int type, u_int32_t, void *);
314 int input_gssapi_error(int, u_int32_t, void *);
315 int input_gssapi_errtok(int, u_int32_t, void *);
318 void userauth(Authctxt *, char *);
320 static int sign_and_send_pubkey(Authctxt *, Identity *);
321 static void pubkey_prepare(Authctxt *);
322 static void pubkey_cleanup(Authctxt *);
323 static Key *load_identity_file(char *, int);
325 static Authmethod *authmethod_get(char *authlist);
326 static Authmethod *authmethod_lookup(const char *name);
327 static char *authmethods_get(void);
329 Authmethod authmethods[] = {
334 &options.gss_authentication,
340 &options.hostbased_authentication,
345 &options.pubkey_authentication,
347 {"keyboard-interactive",
350 &options.kbd_interactive_authentication,
351 &options.batch_mode},
355 &options.password_authentication,
356 &options.batch_mode},
362 {NULL, NULL, NULL, NULL, NULL}
366 ssh_userauth2(const char *local_user, const char *server_user, char *host,
367 Sensitive *sensitive)
372 if (options.challenge_response_authentication)
373 options.kbd_interactive_authentication = 1;
375 packet_start(SSH2_MSG_SERVICE_REQUEST);
376 packet_put_cstring("ssh-userauth");
378 debug("SSH2_MSG_SERVICE_REQUEST sent");
380 type = packet_read();
381 if (type != SSH2_MSG_SERVICE_ACCEPT)
382 fatal("Server denied authentication request: %d", type);
383 if (packet_remaining() > 0) {
384 char *reply = packet_get_string(NULL);
385 debug2("service_accept: %s", reply);
388 debug2("buggy server: service_accept w/o service");
391 debug("SSH2_MSG_SERVICE_ACCEPT received");
393 if (options.preferred_authentications == NULL)
394 options.preferred_authentications = authmethods_get();
396 /* setup authentication context */
397 memset(&authctxt, 0, sizeof(authctxt));
398 pubkey_prepare(&authctxt);
399 authctxt.server_user = server_user;
400 authctxt.local_user = local_user;
401 authctxt.host = host;
402 authctxt.service = "ssh-connection"; /* service name */
403 authctxt.success = 0;
404 authctxt.method = authmethod_lookup("none");
405 authctxt.authlist = NULL;
406 authctxt.methoddata = NULL;
407 authctxt.sensitive = sensitive;
408 authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
409 authctxt.info_req_seen = 0;
410 authctxt.agent_fd = -1;
411 if (authctxt.method == NULL)
412 fatal("ssh_userauth2: internal error: cannot send userauth none request");
414 /* initial userauth request */
415 userauth_none(&authctxt);
417 dispatch_init(&input_userauth_error);
418 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
419 dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
420 dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
421 dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
423 pubkey_cleanup(&authctxt);
424 dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
426 debug("Authentication succeeded (%s).", authctxt.method->name);
430 userauth(Authctxt *authctxt, char *authlist)
432 if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
433 authctxt->method->cleanup(authctxt);
435 free(authctxt->methoddata);
436 authctxt->methoddata = NULL;
437 if (authlist == NULL) {
438 authlist = authctxt->authlist;
440 free(authctxt->authlist);
441 authctxt->authlist = authlist;
444 Authmethod *method = authmethod_get(authlist);
446 fatal("Permission denied (%s).", authlist);
447 authctxt->method = method;
449 /* reset the per method handler */
450 dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
451 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
453 /* and try new method */
454 if (method->userauth(authctxt) != 0) {
455 debug2("we sent a %s packet, wait for reply", method->name);
458 debug2("we did not send a packet, disable method");
459 method->enabled = NULL;
466 input_userauth_error(int type, u_int32_t seq, void *ctxt)
468 fatal("input_userauth_error: bad message during authentication: "
475 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
477 char *msg, *raw, *lang;
480 debug3("input_userauth_banner");
481 raw = packet_get_string(&len);
482 lang = packet_get_string(NULL);
483 if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
486 msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
487 strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
488 fprintf(stderr, "%s", msg);
498 input_userauth_success(int type, u_int32_t seq, void *ctxt)
500 Authctxt *authctxt = ctxt;
502 if (authctxt == NULL)
503 fatal("input_userauth_success: no authentication context");
504 free(authctxt->authlist);
505 authctxt->authlist = NULL;
506 if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
507 authctxt->method->cleanup(authctxt);
508 free(authctxt->methoddata);
509 authctxt->methoddata = NULL;
510 authctxt->success = 1; /* break out */
515 input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
517 Authctxt *authctxt = ctxt;
519 if (authctxt == NULL)
520 fatal("%s: no authentication context", __func__);
522 fatal("Unexpected authentication success during %s.",
523 authctxt->method->name);
529 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
531 Authctxt *authctxt = ctxt;
532 char *authlist = NULL;
535 if (authctxt == NULL)
536 fatal("input_userauth_failure: no authentication context");
538 authlist = packet_get_string(NULL);
539 partial = packet_get_char();
543 logit("Authenticated with partial success.");
545 pubkey_cleanup(authctxt);
546 pubkey_prepare(authctxt);
548 debug("Authentications that can continue: %s", authlist);
550 userauth(authctxt, authlist);
556 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
558 Authctxt *authctxt = ctxt;
562 int pktype, sent = 0;
567 if (authctxt == NULL)
568 fatal("input_userauth_pk_ok: no authentication context");
569 if (datafellows & SSH_BUG_PKOK) {
570 /* this is similar to SSH_BUG_PKAUTH */
571 debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
572 pkblob = packet_get_string(&blen);
574 buffer_append(&b, pkblob, blen);
575 pkalg = buffer_get_string(&b, &alen);
578 pkalg = packet_get_string(&alen);
579 pkblob = packet_get_string(&blen);
583 debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
585 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
586 debug("unknown pkalg %s", pkalg);
589 if ((key = key_from_blob(pkblob, blen)) == NULL) {
590 debug("no key from blob. pkalg %s", pkalg);
593 if (key->type != pktype) {
594 error("input_userauth_pk_ok: type mismatch "
595 "for decoded key (received %d, expected %d)",
599 if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
600 SSH_FP_DEFAULT)) == NULL)
602 debug2("input_userauth_pk_ok: fp %s", fp);
606 * search keys in the reverse order, because last candidate has been
607 * moved to the end of the queue. this also avoids confusion by
610 TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
611 if (key_equal(key, id->key)) {
612 sent = sign_and_send_pubkey(authctxt, id);
622 /* try another method if we did not send a packet */
624 userauth(authctxt, NULL);
630 userauth_gssapi(Authctxt *authctxt)
632 Gssctxt *gssctxt = NULL;
633 static gss_OID_set gss_supported = NULL;
634 static u_int mech = 0;
638 /* Try one GSSAPI method at a time, rather than sending them all at
641 if (gss_supported == NULL)
642 gss_indicate_mechs(&min, &gss_supported);
644 /* Check to see if the mechanism is usable before we offer it */
645 while (mech < gss_supported->count && !ok) {
646 /* My DER encoding requires length<128 */
647 if (gss_supported->elements[mech].length < 128 &&
648 ssh_gssapi_check_mechanism(&gssctxt,
649 &gss_supported->elements[mech], authctxt->host)) {
650 ok = 1; /* Mechanism works */
659 authctxt->methoddata=(void *)gssctxt;
661 packet_start(SSH2_MSG_USERAUTH_REQUEST);
662 packet_put_cstring(authctxt->server_user);
663 packet_put_cstring(authctxt->service);
664 packet_put_cstring(authctxt->method->name);
668 packet_put_int((gss_supported->elements[mech].length) + 2);
669 packet_put_char(SSH_GSS_OIDTYPE);
670 packet_put_char(gss_supported->elements[mech].length);
671 packet_put_raw(gss_supported->elements[mech].elements,
672 gss_supported->elements[mech].length);
676 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
677 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
678 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
679 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
681 mech++; /* Move along to next candidate */
687 process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
689 Authctxt *authctxt = ctxt;
690 Gssctxt *gssctxt = authctxt->methoddata;
691 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
692 gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
693 gss_buffer_desc gssbuf;
694 OM_uint32 status, ms, flags;
697 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
698 recv_tok, &send_tok, &flags);
700 if (send_tok.length > 0) {
701 if (GSS_ERROR(status))
702 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
704 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
706 packet_put_string(send_tok.value, send_tok.length);
708 gss_release_buffer(&ms, &send_tok);
711 if (status == GSS_S_COMPLETE) {
712 /* send either complete or MIC, depending on mechanism */
713 if (!(flags & GSS_C_INTEG_FLAG)) {
714 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
717 ssh_gssapi_buildmic(&b, authctxt->server_user,
718 authctxt->service, "gssapi-with-mic");
720 gssbuf.value = buffer_ptr(&b);
721 gssbuf.length = buffer_len(&b);
723 status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
725 if (!GSS_ERROR(status)) {
726 packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
727 packet_put_string(mic.value, mic.length);
733 gss_release_buffer(&ms, &mic);
742 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
744 Authctxt *authctxt = ctxt;
749 if (authctxt == NULL)
750 fatal("input_gssapi_response: no authentication context");
751 gssctxt = authctxt->methoddata;
754 oidv = packet_get_string(&oidlen);
757 oidv[0] != SSH_GSS_OIDTYPE ||
758 oidv[1] != oidlen - 2) {
760 debug("Badly encoded mechanism OID received");
761 userauth(authctxt, NULL);
765 if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
766 fatal("Server returned different OID than expected");
772 if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
773 /* Start again with next method on list */
774 debug("Trying to start again");
775 userauth(authctxt, NULL);
783 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
785 Authctxt *authctxt = ctxt;
786 gss_buffer_desc recv_tok;
790 if (authctxt == NULL)
791 fatal("input_gssapi_response: no authentication context");
793 recv_tok.value = packet_get_string(&slen);
794 recv_tok.length = slen; /* safe typecast */
798 status = process_gssapi_token(ctxt, &recv_tok);
800 free(recv_tok.value);
802 if (GSS_ERROR(status)) {
803 /* Start again with the next method in the list */
804 userauth(authctxt, NULL);
812 input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
814 Authctxt *authctxt = ctxt;
816 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
817 gss_buffer_desc recv_tok;
821 if (authctxt == NULL)
822 fatal("input_gssapi_response: no authentication context");
823 gssctxt = authctxt->methoddata;
825 recv_tok.value = packet_get_string(&len);
826 recv_tok.length = len;
830 /* Stick it into GSSAPI and see what it says */
831 (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
832 &recv_tok, &send_tok, NULL);
834 free(recv_tok.value);
835 gss_release_buffer(&ms, &send_tok);
837 /* Server will be returning a failed packet after this one */
843 input_gssapi_error(int type, u_int32_t plen, void *ctxt)
848 /* maj */(void)packet_get_int();
849 /* min */(void)packet_get_int();
850 msg=packet_get_string(NULL);
851 lang=packet_get_string(NULL);
855 debug("Server GSSAPI Error:\n%s", msg);
863 userauth_none(Authctxt *authctxt)
865 /* initial userauth request */
866 packet_start(SSH2_MSG_USERAUTH_REQUEST);
867 packet_put_cstring(authctxt->server_user);
868 packet_put_cstring(authctxt->service);
869 packet_put_cstring(authctxt->method->name);
875 userauth_passwd(Authctxt *authctxt)
877 static int attempt = 0;
880 const char *host = options.host_key_alias ? options.host_key_alias :
883 if (attempt++ >= options.number_of_password_prompts)
887 error("Permission denied, please try again.");
889 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
890 authctxt->server_user, host);
891 password = read_passphrase(prompt, 0);
892 packet_start(SSH2_MSG_USERAUTH_REQUEST);
893 packet_put_cstring(authctxt->server_user);
894 packet_put_cstring(authctxt->service);
895 packet_put_cstring(authctxt->method->name);
897 packet_put_cstring(password);
898 explicit_bzero(password, strlen(password));
900 packet_add_padding(64);
903 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
904 &input_userauth_passwd_changereq);
910 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
914 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
916 Authctxt *authctxt = ctxt;
917 char *info, *lang, *password = NULL, *retype = NULL;
919 const char *host = options.host_key_alias ? options.host_key_alias :
922 debug2("input_userauth_passwd_changereq");
924 if (authctxt == NULL)
925 fatal("input_userauth_passwd_changereq: "
926 "no authentication context");
928 info = packet_get_string(NULL);
929 lang = packet_get_string(NULL);
930 if (strlen(info) > 0)
934 packet_start(SSH2_MSG_USERAUTH_REQUEST);
935 packet_put_cstring(authctxt->server_user);
936 packet_put_cstring(authctxt->service);
937 packet_put_cstring(authctxt->method->name);
938 packet_put_char(1); /* additional info */
939 snprintf(prompt, sizeof(prompt),
940 "Enter %.30s@%.128s's old password: ",
941 authctxt->server_user, host);
942 password = read_passphrase(prompt, 0);
943 packet_put_cstring(password);
944 explicit_bzero(password, strlen(password));
947 while (password == NULL) {
948 snprintf(prompt, sizeof(prompt),
949 "Enter %.30s@%.128s's new password: ",
950 authctxt->server_user, host);
951 password = read_passphrase(prompt, RP_ALLOW_EOF);
952 if (password == NULL) {
956 snprintf(prompt, sizeof(prompt),
957 "Retype %.30s@%.128s's new password: ",
958 authctxt->server_user, host);
959 retype = read_passphrase(prompt, 0);
960 if (strcmp(password, retype) != 0) {
961 explicit_bzero(password, strlen(password));
963 logit("Mismatch; try again, EOF to quit.");
966 explicit_bzero(retype, strlen(retype));
969 packet_put_cstring(password);
970 explicit_bzero(password, strlen(password));
972 packet_add_padding(64);
975 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
976 &input_userauth_passwd_changereq);
981 identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
982 const u_char *data, size_t datalen, u_int compat)
987 /* the agent supports this key */
989 return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
990 data, datalen, compat);
993 * we have already loaded the private key or
994 * the private key is stored in external hardware
996 if (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))
997 return (sshkey_sign(id->key, sigp, lenp, data, datalen,
999 /* load the private key from the file */
1000 if ((prv = load_identity_file(id->filename, id->userprovided)) == NULL)
1001 return (-1); /* XXX return decent error code */
1002 ret = sshkey_sign(prv, sigp, lenp, data, datalen, compat);
1008 sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1011 u_char *blob, *signature;
1019 if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1020 SSH_FP_DEFAULT)) == NULL)
1022 debug3("sign_and_send_pubkey: %s %s", key_type(id->key), fp);
1025 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1026 /* we cannot handle this key */
1027 debug3("sign_and_send_pubkey: cannot handle key");
1030 /* data to be signed */
1032 if (datafellows & SSH_OLD_SESSIONID) {
1033 buffer_append(&b, session_id2, session_id2_len);
1034 skip = session_id2_len;
1036 buffer_put_string(&b, session_id2, session_id2_len);
1037 skip = buffer_len(&b);
1039 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1040 buffer_put_cstring(&b, authctxt->server_user);
1041 buffer_put_cstring(&b,
1042 datafellows & SSH_BUG_PKSERVICE ?
1045 if (datafellows & SSH_BUG_PKAUTH) {
1046 buffer_put_char(&b, have_sig);
1048 buffer_put_cstring(&b, authctxt->method->name);
1049 buffer_put_char(&b, have_sig);
1050 buffer_put_cstring(&b, key_ssh_name(id->key));
1052 buffer_put_string(&b, blob, bloblen);
1054 /* generate signature */
1055 ret = identity_sign(id, &signature, &slen,
1056 buffer_ptr(&b), buffer_len(&b), datafellows);
1065 if (datafellows & SSH_BUG_PKSERVICE) {
1067 buffer_append(&b, session_id2, session_id2_len);
1068 skip = session_id2_len;
1069 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1070 buffer_put_cstring(&b, authctxt->server_user);
1071 buffer_put_cstring(&b, authctxt->service);
1072 buffer_put_cstring(&b, authctxt->method->name);
1073 buffer_put_char(&b, have_sig);
1074 if (!(datafellows & SSH_BUG_PKAUTH))
1075 buffer_put_cstring(&b, key_ssh_name(id->key));
1076 buffer_put_string(&b, blob, bloblen);
1080 /* append signature */
1081 buffer_put_string(&b, signature, slen);
1084 /* skip session id and packet type */
1085 if (buffer_len(&b) < skip + 1)
1086 fatal("userauth_pubkey: internal error");
1087 buffer_consume(&b, skip + 1);
1089 /* put remaining data from buffer into packet */
1090 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1091 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1099 send_pubkey_test(Authctxt *authctxt, Identity *id)
1102 u_int bloblen, have_sig = 0;
1104 debug3("send_pubkey_test");
1106 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1107 /* we cannot handle this key */
1108 debug3("send_pubkey_test: cannot handle key");
1111 /* register callback for USERAUTH_PK_OK message */
1112 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1114 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1115 packet_put_cstring(authctxt->server_user);
1116 packet_put_cstring(authctxt->service);
1117 packet_put_cstring(authctxt->method->name);
1118 packet_put_char(have_sig);
1119 if (!(datafellows & SSH_BUG_PKAUTH))
1120 packet_put_cstring(key_ssh_name(id->key));
1121 packet_put_string(blob, bloblen);
1128 load_identity_file(char *filename, int userprovided)
1131 char prompt[300], *passphrase;
1132 int r, perm_ok = 0, quit = 0, i;
1135 if (stat(filename, &st) < 0) {
1136 (userprovided ? logit : debug3)("no such identity: %s: %s",
1137 filename, strerror(errno));
1140 snprintf(prompt, sizeof prompt,
1141 "Enter passphrase for key '%.100s': ", filename);
1142 for (i = 0; i <= options.number_of_password_prompts; i++) {
1146 passphrase = read_passphrase(prompt, 0);
1147 if (*passphrase == '\0') {
1148 debug2("no passphrase given, try next key");
1153 switch ((r = sshkey_load_private_type(KEY_UNSPEC, filename,
1154 passphrase, &private, NULL, &perm_ok))) {
1157 case SSH_ERR_KEY_WRONG_PASSPHRASE:
1158 if (options.batch_mode) {
1163 debug2("bad passphrase given, try again...");
1165 case SSH_ERR_SYSTEM_ERROR:
1166 if (errno == ENOENT) {
1167 debug2("Load key \"%s\": %s",
1168 filename, ssh_err(r));
1174 error("Load key \"%s\": %s", filename, ssh_err(r));
1179 explicit_bzero(passphrase, strlen(passphrase));
1182 if (private != NULL || quit)
1189 * try keys in the following order:
1190 * 1. agent keys that are found in the config file
1191 * 2. other agent keys
1192 * 3. keys that are only listed in the config file
1195 pubkey_prepare(Authctxt *authctxt)
1197 struct identity *id, *id2, *tmp;
1198 struct idlist agent, files, *preferred;
1200 int agent_fd, i, r, found;
1202 struct ssh_identitylist *idlist;
1204 TAILQ_INIT(&agent); /* keys from the agent */
1205 TAILQ_INIT(&files); /* keys from the config file */
1206 preferred = &authctxt->keys;
1207 TAILQ_INIT(preferred); /* preferred order of keys */
1209 /* list of keys stored in the filesystem and PKCS#11 */
1210 for (i = 0; i < options.num_identity_files; i++) {
1211 key = options.identity_keys[i];
1212 if (key && key->type == KEY_RSA1)
1214 if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1216 options.identity_keys[i] = NULL;
1217 id = xcalloc(1, sizeof(*id));
1219 id->filename = xstrdup(options.identity_files[i]);
1220 id->userprovided = options.identity_file_userprovided[i];
1221 TAILQ_INSERT_TAIL(&files, id, next);
1223 /* Prefer PKCS11 keys that are explicitly listed */
1224 TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1225 if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1228 TAILQ_FOREACH(id2, &files, next) {
1229 if (id2->key == NULL ||
1230 (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1232 if (sshkey_equal(id->key, id2->key)) {
1233 TAILQ_REMOVE(&files, id, next);
1234 TAILQ_INSERT_TAIL(preferred, id, next);
1239 /* If IdentitiesOnly set and key not found then don't use it */
1240 if (!found && options.identities_only) {
1241 TAILQ_REMOVE(&files, id, next);
1242 explicit_bzero(id, sizeof(*id));
1246 /* list of keys supported by the agent */
1247 if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1248 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1249 debug("%s: ssh_get_authentication_socket: %s",
1250 __func__, ssh_err(r));
1251 } else if ((r = ssh_fetch_identitylist(agent_fd, 2, &idlist)) != 0) {
1252 if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1253 debug("%s: ssh_fetch_identitylist: %s",
1254 __func__, ssh_err(r));
1256 for (j = 0; j < idlist->nkeys; j++) {
1258 TAILQ_FOREACH(id, &files, next) {
1260 * agent keys from the config file are
1263 if (sshkey_equal(idlist->keys[j], id->key)) {
1264 TAILQ_REMOVE(&files, id, next);
1265 TAILQ_INSERT_TAIL(preferred, id, next);
1266 id->agent_fd = agent_fd;
1271 if (!found && !options.identities_only) {
1272 id = xcalloc(1, sizeof(*id));
1273 /* XXX "steals" key/comment from idlist */
1274 id->key = idlist->keys[j];
1275 id->filename = idlist->comments[j];
1276 idlist->keys[j] = NULL;
1277 idlist->comments[j] = NULL;
1278 id->agent_fd = agent_fd;
1279 TAILQ_INSERT_TAIL(&agent, id, next);
1282 ssh_free_identitylist(idlist);
1283 /* append remaining agent keys */
1284 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1285 TAILQ_REMOVE(&agent, id, next);
1286 TAILQ_INSERT_TAIL(preferred, id, next);
1288 authctxt->agent_fd = agent_fd;
1290 /* append remaining keys from the config file */
1291 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1292 TAILQ_REMOVE(&files, id, next);
1293 TAILQ_INSERT_TAIL(preferred, id, next);
1295 TAILQ_FOREACH(id, preferred, next) {
1296 debug2("key: %s (%p),%s", id->filename, id->key,
1297 id->userprovided ? " explicit" : "");
1302 pubkey_cleanup(Authctxt *authctxt)
1306 if (authctxt->agent_fd != -1)
1307 ssh_close_authentication_socket(authctxt->agent_fd);
1308 for (id = TAILQ_FIRST(&authctxt->keys); id;
1309 id = TAILQ_FIRST(&authctxt->keys)) {
1310 TAILQ_REMOVE(&authctxt->keys, id, next);
1312 sshkey_free(id->key);
1319 userauth_pubkey(Authctxt *authctxt)
1324 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1327 /* move key to the end of the queue */
1328 TAILQ_REMOVE(&authctxt->keys, id, next);
1329 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1331 * send a test message if we have the public key. for
1332 * encrypted keys we cannot do this and have to load the
1333 * private key instead
1335 if (id->key != NULL) {
1336 if (key_type_plain(id->key->type) == KEY_RSA &&
1337 (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1338 debug("Skipped %s key %s for RSA/MD5 server",
1339 key_type(id->key), id->filename);
1340 } else if (id->key->type != KEY_RSA1) {
1341 debug("Offering %s public key: %s",
1342 key_type(id->key), id->filename);
1343 sent = send_pubkey_test(authctxt, id);
1346 debug("Trying private key: %s", id->filename);
1347 id->key = load_identity_file(id->filename,
1349 if (id->key != NULL) {
1351 if (key_type_plain(id->key->type) == KEY_RSA &&
1352 (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1353 debug("Skipped %s key %s for RSA/MD5 "
1354 "server", key_type(id->key),
1357 sent = sign_and_send_pubkey(
1371 * Send userauth request message specifying keyboard-interactive method.
1374 userauth_kbdint(Authctxt *authctxt)
1376 static int attempt = 0;
1378 if (attempt++ >= options.number_of_password_prompts)
1380 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1381 if (attempt > 1 && !authctxt->info_req_seen) {
1382 debug3("userauth_kbdint: disable: no info_req_seen");
1383 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1387 debug2("userauth_kbdint");
1388 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1389 packet_put_cstring(authctxt->server_user);
1390 packet_put_cstring(authctxt->service);
1391 packet_put_cstring(authctxt->method->name);
1392 packet_put_cstring(""); /* lang */
1393 packet_put_cstring(options.kbd_interactive_devices ?
1394 options.kbd_interactive_devices : "");
1397 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1402 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1405 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1407 Authctxt *authctxt = ctxt;
1408 char *name, *inst, *lang, *prompt, *response;
1409 u_int num_prompts, i;
1412 debug2("input_userauth_info_req");
1414 if (authctxt == NULL)
1415 fatal("input_userauth_info_req: no authentication context");
1417 authctxt->info_req_seen = 1;
1419 name = packet_get_string(NULL);
1420 inst = packet_get_string(NULL);
1421 lang = packet_get_string(NULL);
1422 if (strlen(name) > 0)
1424 if (strlen(inst) > 0)
1430 num_prompts = packet_get_int();
1432 * Begin to build info response packet based on prompts requested.
1433 * We commit to providing the correct number of responses, so if
1434 * further on we run into a problem that prevents this, we have to
1435 * be sure and clean this up and send a correct error response.
1437 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1438 packet_put_int(num_prompts);
1440 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1441 for (i = 0; i < num_prompts; i++) {
1442 prompt = packet_get_string(NULL);
1443 echo = packet_get_char();
1445 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1447 packet_put_cstring(response);
1448 explicit_bzero(response, strlen(response));
1452 packet_check_eom(); /* done with parsing incoming message. */
1454 packet_add_padding(64);
1460 ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1461 const u_char *data, size_t datalen)
1466 int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1467 u_char rversion = 0, version = 2;
1468 void (*osigchld)(int);
1473 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1474 error("%s: not installed: %s", __func__, strerror(errno));
1477 if (fflush(stdout) != 0) {
1478 error("%s: fflush: %s", __func__, strerror(errno));
1482 error("%s: pipe: %s", __func__, strerror(errno));
1485 if (pipe(from) < 0) {
1486 error("%s: pipe: %s", __func__, strerror(errno));
1489 if ((pid = fork()) < 0) {
1490 error("%s: fork: %s", __func__, strerror(errno));
1493 osigchld = signal(SIGCHLD, SIG_DFL);
1495 /* keep the socket on exec */
1496 fcntl(sock, F_SETFD, 0);
1497 permanently_drop_suid(getuid());
1499 if (dup2(from[1], STDOUT_FILENO) < 0)
1500 fatal("%s: dup2: %s", __func__, strerror(errno));
1502 if (dup2(to[0], STDIN_FILENO) < 0)
1503 fatal("%s: dup2: %s", __func__, strerror(errno));
1506 /* Close everything but stdio and the socket */
1507 for (i = STDERR_FILENO + 1; i < sock; i++)
1509 closefrom(sock + 1);
1510 debug3("%s: [child] pid=%ld, exec %s",
1511 __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1512 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1513 fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1519 if ((b = sshbuf_new()) == NULL)
1520 fatal("%s: sshbuf_new failed", __func__);
1521 /* send # of sock, data to be signed */
1522 if ((r = sshbuf_put_u32(b, sock) != 0) ||
1523 (r = sshbuf_put_string(b, data, datalen)) != 0)
1524 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1525 if (ssh_msg_send(to[1], version, b) == -1)
1526 fatal("%s: couldn't send request", __func__);
1528 r = ssh_msg_recv(from[0], b);
1532 error("%s: no reply", __func__);
1537 while (waitpid(pid, &status, 0) < 0) {
1538 if (errno != EINTR) {
1539 error("%s: waitpid %ld: %s",
1540 __func__, (long)pid, strerror(errno));
1544 if (!WIFEXITED(status)) {
1545 error("%s: exited abnormally", __func__);
1548 if (WEXITSTATUS(status) != 0) {
1549 error("%s: exited with status %d",
1550 __func__, WEXITSTATUS(status));
1553 if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1554 error("%s: buffer error: %s", __func__, ssh_err(r));
1557 if (rversion != version) {
1558 error("%s: bad version", __func__);
1561 if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1562 error("%s: buffer error: %s", __func__, ssh_err(r));
1564 signal(SIGCHLD, osigchld);
1568 signal(SIGCHLD, osigchld);
1575 userauth_hostbased(Authctxt *authctxt)
1577 struct ssh *ssh = active_state;
1578 struct sshkey *private = NULL;
1579 struct sshbuf *b = NULL;
1580 const char *service;
1581 u_char *sig = NULL, *keyblob = NULL;
1582 char *fp = NULL, *chost = NULL, *lname = NULL;
1583 size_t siglen = 0, keylen = 0;
1584 int i, r, success = 0;
1586 if (authctxt->ktypes == NULL) {
1587 authctxt->oktypes = xstrdup(options.hostbased_key_types);
1588 authctxt->ktypes = authctxt->oktypes;
1592 * Work through each listed type pattern in HostbasedKeyTypes,
1593 * trying each hostkey that matches the type in turn.
1596 if (authctxt->active_ktype == NULL)
1597 authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1598 if (authctxt->active_ktype == NULL ||
1599 *authctxt->active_ktype == '\0')
1601 debug3("%s: trying key type %s", __func__,
1602 authctxt->active_ktype);
1604 /* check for a useful key */
1606 for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1607 if (authctxt->sensitive->keys[i] == NULL ||
1608 authctxt->sensitive->keys[i]->type == KEY_RSA1 ||
1609 authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1611 if (match_pattern_list(
1612 sshkey_ssh_name(authctxt->sensitive->keys[i]),
1613 authctxt->active_ktype,
1614 strlen(authctxt->active_ktype), 0) != 1)
1616 /* we take and free the key */
1617 private = authctxt->sensitive->keys[i];
1618 authctxt->sensitive->keys[i] = NULL;
1622 if (private != NULL)
1624 /* No more keys of this type; advance */
1625 authctxt->active_ktype = NULL;
1627 if (private == NULL) {
1628 free(authctxt->oktypes);
1629 authctxt->oktypes = authctxt->ktypes = NULL;
1630 authctxt->active_ktype = NULL;
1631 debug("No more client hostkeys for hostbased authentication.");
1635 if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1636 SSH_FP_DEFAULT)) == NULL) {
1637 error("%s: sshkey_fingerprint failed", __func__);
1640 debug("%s: trying hostkey %s %s",
1641 __func__, sshkey_ssh_name(private), fp);
1643 /* figure out a name for the client host */
1644 if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1645 error("%s: cannot get local ipaddr/name", __func__);
1649 /* XXX sshbuf_put_stringf? */
1650 xasprintf(&chost, "%s.", lname);
1651 debug2("%s: chost %s", __func__, chost);
1653 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1656 /* construct data */
1657 if ((b = sshbuf_new()) == NULL) {
1658 error("%s: sshbuf_new failed", __func__);
1661 if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1662 error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1665 if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1666 (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1667 (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1668 (r = sshbuf_put_cstring(b, service)) != 0 ||
1669 (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1670 (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1671 (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1672 (r = sshbuf_put_cstring(b, chost)) != 0 ||
1673 (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1674 error("%s: buffer error: %s", __func__, ssh_err(r));
1679 sshbuf_dump(b, stderr);
1681 if (authctxt->sensitive->external_keysign)
1682 r = ssh_keysign(private, &sig, &siglen,
1683 sshbuf_ptr(b), sshbuf_len(b));
1684 else if ((r = sshkey_sign(private, &sig, &siglen,
1685 sshbuf_ptr(b), sshbuf_len(b), datafellows)) != 0)
1686 debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1688 error("sign using hostkey %s %s failed",
1689 sshkey_ssh_name(private), fp);
1692 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1693 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1694 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1695 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1696 (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1697 (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1698 (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1699 (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1700 (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1701 (r = sshpkt_send(ssh)) != 0) {
1702 error("%s: packet error: %s", __func__, ssh_err(r));
1709 explicit_bzero(sig, siglen);
1716 sshkey_free(private);
1722 /* find auth method */
1725 * given auth method name, if configurable options permit this method fill
1726 * in auth_ident field and return true, otherwise return false.
1729 authmethod_is_enabled(Authmethod *method)
1733 /* return false if options indicate this method is disabled */
1734 if (method->enabled == NULL || *method->enabled == 0)
1736 /* return false if batch mode is enabled but method needs interactive mode */
1737 if (method->batch_flag != NULL && *method->batch_flag != 0)
1743 authmethod_lookup(const char *name)
1745 Authmethod *method = NULL;
1747 for (method = authmethods; method->name != NULL; method++)
1748 if (strcmp(name, method->name) == 0)
1750 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1754 /* XXX internal state */
1755 static Authmethod *current = NULL;
1756 static char *supported = NULL;
1757 static char *preferred = NULL;
1760 * Given the authentication method list sent by the server, return the
1761 * next method we should try. If the server initially sends a nil list,
1762 * use a built-in default list.
1765 authmethod_get(char *authlist)
1770 /* Use a suitable default if we're passed a nil list. */
1771 if (authlist == NULL || strlen(authlist) == 0)
1772 authlist = options.preferred_authentications;
1774 if (supported == NULL || strcmp(authlist, supported) != 0) {
1775 debug3("start over, passed a different list %s", authlist);
1777 supported = xstrdup(authlist);
1778 preferred = options.preferred_authentications;
1779 debug3("preferred %s", preferred);
1781 } else if (current != NULL && authmethod_is_enabled(current))
1785 if ((name = match_list(preferred, supported, &next)) == NULL) {
1786 debug("No more authentication methods to try.");
1791 debug3("authmethod_lookup %s", name);
1792 debug3("remaining preferred: %s", preferred);
1793 if ((current = authmethod_lookup(name)) != NULL &&
1794 authmethod_is_enabled(current)) {
1795 debug3("authmethod_is_enabled %s", name);
1796 debug("Next authentication method: %s", name);
1805 authmethods_get(void)
1807 Authmethod *method = NULL;
1812 for (method = authmethods; method->name != NULL; method++) {
1813 if (authmethod_is_enabled(method)) {
1814 if (buffer_len(&b) > 0)
1815 buffer_append(&b, ",", 1);
1816 buffer_append(&b, method->name, strlen(method->name));
1819 buffer_append(&b, "\0", 1);
1820 list = xstrdup(buffer_ptr(&b));