1 /* $OpenBSD: sshconnect2.c,v 1.186 2010/11/29 23:45:51 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)
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;
86 /* tty_flag is set in ssh.c. use this in ssh_userauth2 */
87 /* if it is set then prevent the switch to the null cipher */
95 u_char *session_id2 = NULL;
96 u_int session_id2_len = 0;
99 struct sockaddr *xxx_hostaddr;
104 verify_host_key_callback(Key *hostkey)
106 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
107 fatal("Host key verification failed.");
112 order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
114 char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
116 struct hostkeys *hostkeys;
119 /* Find all hostkeys for this hostname */
120 get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
121 hostkeys = init_hostkeys();
122 load_hostkeys(hostkeys, hostname, options.user_hostfile2);
123 load_hostkeys(hostkeys, hostname, options.system_hostfile2);
124 load_hostkeys(hostkeys, hostname, options.user_hostfile);
125 load_hostkeys(hostkeys, hostname, options.system_hostfile);
127 oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
128 maxlen = strlen(avail) + 1;
129 first = xmalloc(maxlen);
130 last = xmalloc(maxlen);
131 *first = *last = '\0';
133 #define ALG_APPEND(to, from) \
136 strlcat(to, ",", maxlen); \
137 strlcat(to, from, maxlen); \
140 while ((alg = strsep(&avail, ",")) && *alg != '\0') {
141 if ((ktype = key_type_from_name(alg)) == KEY_UNSPEC)
142 fatal("%s: unknown alg %s", __func__, alg);
143 if (lookup_key_in_hostkeys_by_type(hostkeys,
144 key_type_plain(ktype), NULL))
145 ALG_APPEND(first, alg);
147 ALG_APPEND(last, alg);
150 xasprintf(&ret, "%s%s%s", first, *first == '\0' ? "" : ",", last);
152 debug3("%s: prefer hostkeyalgs: %s", __func__, first);
158 free_hostkeys(hostkeys);
164 ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
169 xxx_hostaddr = hostaddr;
171 if (options.ciphers == (char *)-1) {
172 logit("No valid ciphers for protocol version 2 given, using defaults.");
173 options.ciphers = NULL;
175 if (options.ciphers != NULL) {
176 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
177 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
179 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
180 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
181 myproposal[PROPOSAL_ENC_ALGS_STOC] =
182 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
183 if (options.compression) {
184 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
185 myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
187 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
188 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
190 if (options.macs != NULL) {
191 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
192 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
194 if (options.hostkeyalgorithms != NULL)
195 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
196 options.hostkeyalgorithms;
198 /* Prefer algorithms that we already have keys for */
199 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
200 order_hostkeyalgs(host, hostaddr, port);
202 if (options.kex_algorithms != NULL)
203 myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
205 if (options.rekey_limit)
206 packet_set_rekey_limit((u_int32_t)options.rekey_limit);
208 /* start key exchange */
209 kex = kex_setup(myproposal);
210 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
211 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
212 kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
213 kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
214 kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
215 kex->client_version_string=client_version_string;
216 kex->server_version_string=server_version_string;
217 kex->verify_host_key=&verify_host_key_callback;
221 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
223 if (options.use_roaming && !kex->roaming) {
224 debug("Roaming not allowed by server");
225 options.use_roaming = 0;
228 session_id2 = kex->session_id;
229 session_id2_len = kex->session_id_len;
232 /* send 1st encrypted/maced/compressed message */
233 packet_start(SSH2_MSG_IGNORE);
234 packet_put_cstring("markus");
244 typedef struct Authctxt Authctxt;
245 typedef struct Authmethod Authmethod;
246 typedef struct identity Identity;
247 typedef struct idlist Idlist;
250 TAILQ_ENTRY(identity) next;
251 AuthenticationConnection *ac; /* set if agent supports key */
252 Key *key; /* public/private key */
253 char *filename; /* comment for agent-only keys */
255 int isprivate; /* key points to the private key */
257 TAILQ_HEAD(idlist, identity);
260 const char *server_user;
261 const char *local_user;
265 sig_atomic_t success;
269 AuthenticationConnection *agent;
271 Sensitive *sensitive;
272 /* kbd-interactive */
278 char *name; /* string to compare against server's list */
279 int (*userauth)(Authctxt *authctxt);
280 void (*cleanup)(Authctxt *authctxt);
281 int *enabled; /* flag in option struct that enables method */
282 int *batch_flag; /* flag in option struct that disables method */
285 void input_userauth_success(int, u_int32_t, void *);
286 void input_userauth_success_unexpected(int, u_int32_t, void *);
287 void input_userauth_failure(int, u_int32_t, void *);
288 void input_userauth_banner(int, u_int32_t, void *);
289 void input_userauth_error(int, u_int32_t, void *);
290 void input_userauth_info_req(int, u_int32_t, void *);
291 void input_userauth_pk_ok(int, u_int32_t, void *);
292 void input_userauth_passwd_changereq(int, u_int32_t, void *);
293 void input_userauth_jpake_server_step1(int, u_int32_t, void *);
294 void input_userauth_jpake_server_step2(int, u_int32_t, void *);
295 void input_userauth_jpake_server_confirm(int, u_int32_t, void *);
297 int userauth_none(Authctxt *);
298 int userauth_pubkey(Authctxt *);
299 int userauth_passwd(Authctxt *);
300 int userauth_kbdint(Authctxt *);
301 int userauth_hostbased(Authctxt *);
302 int userauth_jpake(Authctxt *);
304 void userauth_jpake_cleanup(Authctxt *);
307 int userauth_gssapi(Authctxt *authctxt);
308 void input_gssapi_response(int type, u_int32_t, void *);
309 void input_gssapi_token(int type, u_int32_t, void *);
310 void input_gssapi_hash(int type, u_int32_t, void *);
311 void input_gssapi_error(int, u_int32_t, void *);
312 void input_gssapi_errtok(int, u_int32_t, void *);
315 void userauth(Authctxt *, char *);
317 static int sign_and_send_pubkey(Authctxt *, Identity *);
318 static void pubkey_prepare(Authctxt *);
319 static void pubkey_cleanup(Authctxt *);
320 static Key *load_identity_file(char *);
322 static Authmethod *authmethod_get(char *authlist);
323 static Authmethod *authmethod_lookup(const char *name);
324 static char *authmethods_get(void);
326 Authmethod authmethods[] = {
331 &options.gss_authentication,
337 &options.hostbased_authentication,
342 &options.pubkey_authentication,
345 {"jpake-01@openssh.com",
347 userauth_jpake_cleanup,
348 &options.zero_knowledge_password_authentication,
349 &options.batch_mode},
351 {"keyboard-interactive",
354 &options.kbd_interactive_authentication,
355 &options.batch_mode},
359 &options.password_authentication,
360 &options.batch_mode},
366 {NULL, NULL, NULL, NULL, NULL}
370 ssh_userauth2(const char *local_user, const char *server_user, char *host,
371 Sensitive *sensitive)
376 if (options.challenge_response_authentication)
377 options.kbd_interactive_authentication = 1;
379 packet_start(SSH2_MSG_SERVICE_REQUEST);
380 packet_put_cstring("ssh-userauth");
382 debug("SSH2_MSG_SERVICE_REQUEST sent");
384 type = packet_read();
385 if (type != SSH2_MSG_SERVICE_ACCEPT)
386 fatal("Server denied authentication request: %d", type);
387 if (packet_remaining() > 0) {
388 char *reply = packet_get_string(NULL);
389 debug2("service_accept: %s", reply);
392 debug2("buggy server: service_accept w/o service");
395 debug("SSH2_MSG_SERVICE_ACCEPT received");
397 if (options.preferred_authentications == NULL)
398 options.preferred_authentications = authmethods_get();
400 /* setup authentication context */
401 memset(&authctxt, 0, sizeof(authctxt));
402 pubkey_prepare(&authctxt);
403 authctxt.server_user = server_user;
404 authctxt.local_user = local_user;
405 authctxt.host = host;
406 authctxt.service = "ssh-connection"; /* service name */
407 authctxt.success = 0;
408 authctxt.method = authmethod_lookup("none");
409 authctxt.authlist = NULL;
410 authctxt.methoddata = NULL;
411 authctxt.sensitive = sensitive;
412 authctxt.info_req_seen = 0;
413 if (authctxt.method == NULL)
414 fatal("ssh_userauth2: internal error: cannot send userauth none request");
416 /* initial userauth request */
417 userauth_none(&authctxt);
419 dispatch_init(&input_userauth_error);
420 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
421 dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
422 dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
423 dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
425 pubkey_cleanup(&authctxt);
426 dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
428 /* if the user wants to use the none cipher do it */
429 /* post authentication and only if the right conditions are met */
430 /* both of the NONE commands must be true and there must be no */
432 if ((options.none_switch == 1) && (options.none_enabled == 1))
434 if (!tty_flag) /* no null on tty sessions */
436 debug("Requesting none rekeying...");
437 myproposal[PROPOSAL_ENC_ALGS_STOC] = "none";
438 myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none";
439 kex_prop2buf(&xxx_kex->my,myproposal);
440 packet_request_rekeying();
441 fprintf(stderr, "WARNING: ENABLED NONE CIPHER\n");
445 /* requested NONE cipher when in a tty */
446 debug("Cannot switch to NONE cipher with tty allocated");
447 fprintf(stderr, "NONE cipher switch disabled when a TTY is allocated\n");
450 debug("Authentication succeeded (%s).", authctxt.method->name);
454 userauth(Authctxt *authctxt, char *authlist)
456 if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
457 authctxt->method->cleanup(authctxt);
459 if (authctxt->methoddata) {
460 xfree(authctxt->methoddata);
461 authctxt->methoddata = NULL;
463 if (authlist == NULL) {
464 authlist = authctxt->authlist;
466 if (authctxt->authlist)
467 xfree(authctxt->authlist);
468 authctxt->authlist = authlist;
471 Authmethod *method = authmethod_get(authlist);
473 fatal("Permission denied (%s).", authlist);
474 authctxt->method = method;
476 /* reset the per method handler */
477 dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
478 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
480 /* and try new method */
481 if (method->userauth(authctxt) != 0) {
482 debug2("we sent a %s packet, wait for reply", method->name);
485 debug2("we did not send a packet, disable method");
486 method->enabled = NULL;
493 input_userauth_error(int type, u_int32_t seq, void *ctxt)
495 fatal("input_userauth_error: bad message during authentication: "
501 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
503 char *msg, *raw, *lang;
506 debug3("input_userauth_banner");
507 raw = packet_get_string(&len);
508 lang = packet_get_string(NULL);
509 if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
512 msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
513 strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
514 fprintf(stderr, "%s", msg);
523 input_userauth_success(int type, u_int32_t seq, void *ctxt)
525 Authctxt *authctxt = ctxt;
527 if (authctxt == NULL)
528 fatal("input_userauth_success: no authentication context");
529 if (authctxt->authlist) {
530 xfree(authctxt->authlist);
531 authctxt->authlist = NULL;
533 if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
534 authctxt->method->cleanup(authctxt);
535 if (authctxt->methoddata) {
536 xfree(authctxt->methoddata);
537 authctxt->methoddata = NULL;
539 authctxt->success = 1; /* break out */
543 input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
545 Authctxt *authctxt = ctxt;
547 if (authctxt == NULL)
548 fatal("%s: no authentication context", __func__);
550 fatal("Unexpected authentication success during %s.",
551 authctxt->method->name);
556 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
558 Authctxt *authctxt = ctxt;
559 char *authlist = NULL;
562 if (authctxt == NULL)
563 fatal("input_userauth_failure: no authentication context");
565 authlist = packet_get_string(NULL);
566 partial = packet_get_char();
570 logit("Authenticated with partial success.");
571 debug("Authentications that can continue: %s", authlist);
573 userauth(authctxt, authlist);
578 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
580 Authctxt *authctxt = ctxt;
584 int pktype, sent = 0;
589 if (authctxt == NULL)
590 fatal("input_userauth_pk_ok: no authentication context");
591 if (datafellows & SSH_BUG_PKOK) {
592 /* this is similar to SSH_BUG_PKAUTH */
593 debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
594 pkblob = packet_get_string(&blen);
596 buffer_append(&b, pkblob, blen);
597 pkalg = buffer_get_string(&b, &alen);
600 pkalg = packet_get_string(&alen);
601 pkblob = packet_get_string(&blen);
605 debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
607 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
608 debug("unknown pkalg %s", pkalg);
611 if ((key = key_from_blob(pkblob, blen)) == NULL) {
612 debug("no key from blob. pkalg %s", pkalg);
615 if (key->type != pktype) {
616 error("input_userauth_pk_ok: type mismatch "
617 "for decoded key (received %d, expected %d)",
621 fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
622 debug2("input_userauth_pk_ok: fp %s", fp);
626 * search keys in the reverse order, because last candidate has been
627 * moved to the end of the queue. this also avoids confusion by
630 TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
631 if (key_equal(key, id->key)) {
632 sent = sign_and_send_pubkey(authctxt, id);
642 /* try another method if we did not send a packet */
644 userauth(authctxt, NULL);
649 userauth_gssapi(Authctxt *authctxt)
651 Gssctxt *gssctxt = NULL;
652 static gss_OID_set gss_supported = NULL;
653 static u_int mech = 0;
657 /* Try one GSSAPI method at a time, rather than sending them all at
660 if (gss_supported == NULL)
661 gss_indicate_mechs(&min, &gss_supported);
663 /* Check to see if the mechanism is usable before we offer it */
664 while (mech < gss_supported->count && !ok) {
665 /* My DER encoding requires length<128 */
666 if (gss_supported->elements[mech].length < 128 &&
667 ssh_gssapi_check_mechanism(&gssctxt,
668 &gss_supported->elements[mech], authctxt->host)) {
669 ok = 1; /* Mechanism works */
678 authctxt->methoddata=(void *)gssctxt;
680 packet_start(SSH2_MSG_USERAUTH_REQUEST);
681 packet_put_cstring(authctxt->server_user);
682 packet_put_cstring(authctxt->service);
683 packet_put_cstring(authctxt->method->name);
687 packet_put_int((gss_supported->elements[mech].length) + 2);
688 packet_put_char(SSH_GSS_OIDTYPE);
689 packet_put_char(gss_supported->elements[mech].length);
690 packet_put_raw(gss_supported->elements[mech].elements,
691 gss_supported->elements[mech].length);
695 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
696 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
697 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
698 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
700 mech++; /* Move along to next candidate */
706 process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
708 Authctxt *authctxt = ctxt;
709 Gssctxt *gssctxt = authctxt->methoddata;
710 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
711 gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
712 gss_buffer_desc gssbuf;
713 OM_uint32 status, ms, flags;
716 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
717 recv_tok, &send_tok, &flags);
719 if (send_tok.length > 0) {
720 if (GSS_ERROR(status))
721 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
723 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
725 packet_put_string(send_tok.value, send_tok.length);
727 gss_release_buffer(&ms, &send_tok);
730 if (status == GSS_S_COMPLETE) {
731 /* send either complete or MIC, depending on mechanism */
732 if (!(flags & GSS_C_INTEG_FLAG)) {
733 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
736 ssh_gssapi_buildmic(&b, authctxt->server_user,
737 authctxt->service, "gssapi-with-mic");
739 gssbuf.value = buffer_ptr(&b);
740 gssbuf.length = buffer_len(&b);
742 status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
744 if (!GSS_ERROR(status)) {
745 packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
746 packet_put_string(mic.value, mic.length);
752 gss_release_buffer(&ms, &mic);
761 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
763 Authctxt *authctxt = ctxt;
768 if (authctxt == NULL)
769 fatal("input_gssapi_response: no authentication context");
770 gssctxt = authctxt->methoddata;
773 oidv = packet_get_string(&oidlen);
776 oidv[0] != SSH_GSS_OIDTYPE ||
777 oidv[1] != oidlen - 2) {
779 debug("Badly encoded mechanism OID received");
780 userauth(authctxt, NULL);
784 if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
785 fatal("Server returned different OID than expected");
791 if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
792 /* Start again with next method on list */
793 debug("Trying to start again");
794 userauth(authctxt, NULL);
801 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
803 Authctxt *authctxt = ctxt;
804 gss_buffer_desc recv_tok;
808 if (authctxt == NULL)
809 fatal("input_gssapi_response: no authentication context");
811 recv_tok.value = packet_get_string(&slen);
812 recv_tok.length = slen; /* safe typecast */
816 status = process_gssapi_token(ctxt, &recv_tok);
818 xfree(recv_tok.value);
820 if (GSS_ERROR(status)) {
821 /* Start again with the next method in the list */
822 userauth(authctxt, NULL);
829 input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
831 Authctxt *authctxt = ctxt;
833 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
834 gss_buffer_desc recv_tok;
835 OM_uint32 status, ms;
838 if (authctxt == NULL)
839 fatal("input_gssapi_response: no authentication context");
840 gssctxt = authctxt->methoddata;
842 recv_tok.value = packet_get_string(&len);
843 recv_tok.length = len;
847 /* Stick it into GSSAPI and see what it says */
848 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
849 &recv_tok, &send_tok, NULL);
851 xfree(recv_tok.value);
852 gss_release_buffer(&ms, &send_tok);
854 /* Server will be returning a failed packet after this one */
859 input_gssapi_error(int type, u_int32_t plen, void *ctxt)
865 maj=packet_get_int();
866 min=packet_get_int();
867 msg=packet_get_string(NULL);
868 lang=packet_get_string(NULL);
872 debug("Server GSSAPI Error:\n%s", msg);
879 userauth_none(Authctxt *authctxt)
881 /* initial userauth request */
882 packet_start(SSH2_MSG_USERAUTH_REQUEST);
883 packet_put_cstring(authctxt->server_user);
884 packet_put_cstring(authctxt->service);
885 packet_put_cstring(authctxt->method->name);
891 userauth_passwd(Authctxt *authctxt)
893 static int attempt = 0;
896 const char *host = options.host_key_alias ? options.host_key_alias :
899 if (attempt++ >= options.number_of_password_prompts)
903 error("Permission denied, please try again.");
905 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
906 authctxt->server_user, host);
907 password = read_passphrase(prompt, 0);
908 packet_start(SSH2_MSG_USERAUTH_REQUEST);
909 packet_put_cstring(authctxt->server_user);
910 packet_put_cstring(authctxt->service);
911 packet_put_cstring(authctxt->method->name);
913 packet_put_cstring(password);
914 memset(password, 0, strlen(password));
916 packet_add_padding(64);
919 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
920 &input_userauth_passwd_changereq);
926 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
930 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
932 Authctxt *authctxt = ctxt;
933 char *info, *lang, *password = NULL, *retype = NULL;
935 const char *host = options.host_key_alias ? options.host_key_alias :
938 debug2("input_userauth_passwd_changereq");
940 if (authctxt == NULL)
941 fatal("input_userauth_passwd_changereq: "
942 "no authentication context");
944 info = packet_get_string(NULL);
945 lang = packet_get_string(NULL);
946 if (strlen(info) > 0)
950 packet_start(SSH2_MSG_USERAUTH_REQUEST);
951 packet_put_cstring(authctxt->server_user);
952 packet_put_cstring(authctxt->service);
953 packet_put_cstring(authctxt->method->name);
954 packet_put_char(1); /* additional info */
955 snprintf(prompt, sizeof(prompt),
956 "Enter %.30s@%.128s's old password: ",
957 authctxt->server_user, host);
958 password = read_passphrase(prompt, 0);
959 packet_put_cstring(password);
960 memset(password, 0, strlen(password));
963 while (password == NULL) {
964 snprintf(prompt, sizeof(prompt),
965 "Enter %.30s@%.128s's new password: ",
966 authctxt->server_user, host);
967 password = read_passphrase(prompt, RP_ALLOW_EOF);
968 if (password == NULL) {
972 snprintf(prompt, sizeof(prompt),
973 "Retype %.30s@%.128s's new password: ",
974 authctxt->server_user, host);
975 retype = read_passphrase(prompt, 0);
976 if (strcmp(password, retype) != 0) {
977 memset(password, 0, strlen(password));
979 logit("Mismatch; try again, EOF to quit.");
982 memset(retype, 0, strlen(retype));
985 packet_put_cstring(password);
986 memset(password, 0, strlen(password));
988 packet_add_padding(64);
991 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
992 &input_userauth_passwd_changereq);
997 pw_encrypt(const char *password, const char *crypt_scheme, const char *salt)
999 /* OpenBSD crypt(3) handles all of these */
1000 if (strcmp(crypt_scheme, "crypt") == 0 ||
1001 strcmp(crypt_scheme, "bcrypt") == 0 ||
1002 strcmp(crypt_scheme, "md5crypt") == 0 ||
1003 strcmp(crypt_scheme, "crypt-extended") == 0)
1004 return xstrdup(crypt(password, salt));
1005 error("%s: unsupported password encryption scheme \"%.100s\"",
1006 __func__, crypt_scheme);
1011 jpake_password_to_secret(Authctxt *authctxt, const char *crypt_scheme,
1014 char prompt[256], *password, *crypted;
1019 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password (JPAKE): ",
1020 authctxt->server_user, authctxt->host);
1021 password = read_passphrase(prompt, 0);
1023 if ((crypted = pw_encrypt(password, crypt_scheme, salt)) == NULL) {
1024 logit("Disabling %s authentication", authctxt->method->name);
1025 authctxt->method->enabled = NULL;
1026 /* Continue with an empty password to fail gracefully */
1027 crypted = xstrdup("");
1031 debug3("%s: salt = %s", __func__, salt);
1032 debug3("%s: scheme = %s", __func__, crypt_scheme);
1033 debug3("%s: crypted = %s", __func__, crypted);
1036 if (hash_buffer(crypted, strlen(crypted), EVP_sha256(),
1037 &secret, &secret_len) != 0)
1038 fatal("%s: hash_buffer", __func__);
1040 bzero(password, strlen(password));
1041 bzero(crypted, strlen(crypted));
1045 if ((ret = BN_bin2bn(secret, secret_len, NULL)) == NULL)
1046 fatal("%s: BN_bin2bn (secret)", __func__);
1047 bzero(secret, secret_len);
1055 input_userauth_jpake_server_step1(int type, u_int32_t seq, void *ctxt)
1057 Authctxt *authctxt = ctxt;
1058 struct jpake_ctx *pctx = authctxt->methoddata;
1059 u_char *x3_proof, *x4_proof, *x2_s_proof;
1060 u_int x3_proof_len, x4_proof_len, x2_s_proof_len;
1061 char *crypt_scheme, *salt;
1063 /* Disable this message */
1064 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1, NULL);
1066 if ((pctx->g_x3 = BN_new()) == NULL ||
1067 (pctx->g_x4 = BN_new()) == NULL)
1068 fatal("%s: BN_new", __func__);
1070 /* Fetch step 1 values */
1071 crypt_scheme = packet_get_string(NULL);
1072 salt = packet_get_string(NULL);
1073 pctx->server_id = packet_get_string(&pctx->server_id_len);
1074 packet_get_bignum2(pctx->g_x3);
1075 packet_get_bignum2(pctx->g_x4);
1076 x3_proof = packet_get_string(&x3_proof_len);
1077 x4_proof = packet_get_string(&x4_proof_len);
1080 JPAKE_DEBUG_CTX((pctx, "step 1 received in %s", __func__));
1082 /* Obtain password and derive secret */
1083 pctx->s = jpake_password_to_secret(authctxt, crypt_scheme, salt);
1084 bzero(crypt_scheme, strlen(crypt_scheme));
1085 bzero(salt, strlen(salt));
1086 xfree(crypt_scheme);
1088 JPAKE_DEBUG_BN((pctx->s, "%s: s = ", __func__));
1090 /* Calculate step 2 values */
1091 jpake_step2(pctx->grp, pctx->s, pctx->g_x1,
1092 pctx->g_x3, pctx->g_x4, pctx->x2,
1093 pctx->server_id, pctx->server_id_len,
1094 pctx->client_id, pctx->client_id_len,
1095 x3_proof, x3_proof_len,
1096 x4_proof, x4_proof_len,
1098 &x2_s_proof, &x2_s_proof_len);
1100 bzero(x3_proof, x3_proof_len);
1101 bzero(x4_proof, x4_proof_len);
1105 JPAKE_DEBUG_CTX((pctx, "step 2 sending in %s", __func__));
1107 /* Send values for step 2 */
1108 packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2);
1109 packet_put_bignum2(pctx->a);
1110 packet_put_string(x2_s_proof, x2_s_proof_len);
1113 bzero(x2_s_proof, x2_s_proof_len);
1116 /* Expect step 2 packet from peer */
1117 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2,
1118 input_userauth_jpake_server_step2);
1123 input_userauth_jpake_server_step2(int type, u_int32_t seq, void *ctxt)
1125 Authctxt *authctxt = ctxt;
1126 struct jpake_ctx *pctx = authctxt->methoddata;
1128 u_int x4_s_proof_len;
1130 /* Disable this message */
1131 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2, NULL);
1133 if ((pctx->b = BN_new()) == NULL)
1134 fatal("%s: BN_new", __func__);
1136 /* Fetch step 2 values */
1137 packet_get_bignum2(pctx->b);
1138 x4_s_proof = packet_get_string(&x4_s_proof_len);
1141 JPAKE_DEBUG_CTX((pctx, "step 2 received in %s", __func__));
1143 /* Derive shared key and calculate confirmation hash */
1144 jpake_key_confirm(pctx->grp, pctx->s, pctx->b,
1145 pctx->x2, pctx->g_x1, pctx->g_x2, pctx->g_x3, pctx->g_x4,
1146 pctx->client_id, pctx->client_id_len,
1147 pctx->server_id, pctx->server_id_len,
1148 session_id2, session_id2_len,
1149 x4_s_proof, x4_s_proof_len,
1151 &pctx->h_k_cid_sessid, &pctx->h_k_cid_sessid_len);
1153 bzero(x4_s_proof, x4_s_proof_len);
1156 JPAKE_DEBUG_CTX((pctx, "confirm sending in %s", __func__));
1158 /* Send key confirmation proof */
1159 packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM);
1160 packet_put_string(pctx->h_k_cid_sessid, pctx->h_k_cid_sessid_len);
1163 /* Expect confirmation from peer */
1164 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM,
1165 input_userauth_jpake_server_confirm);
1170 input_userauth_jpake_server_confirm(int type, u_int32_t seq, void *ctxt)
1172 Authctxt *authctxt = ctxt;
1173 struct jpake_ctx *pctx = authctxt->methoddata;
1175 /* Disable this message */
1176 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM, NULL);
1178 pctx->h_k_sid_sessid = packet_get_string(&pctx->h_k_sid_sessid_len);
1181 JPAKE_DEBUG_CTX((pctx, "confirm received in %s", __func__));
1183 /* Verify expected confirmation hash */
1184 if (jpake_check_confirm(pctx->k,
1185 pctx->server_id, pctx->server_id_len,
1186 session_id2, session_id2_len,
1187 pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len) == 1)
1188 debug("%s: %s success", __func__, authctxt->method->name);
1190 debug("%s: confirmation mismatch", __func__);
1191 /* XXX stash this so if auth succeeds then we can warn/kill */
1194 userauth_jpake_cleanup(authctxt);
1199 identity_sign(Identity *id, u_char **sigp, u_int *lenp,
1200 u_char *data, u_int datalen)
1205 /* the agent supports this key */
1207 return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
1210 * we have already loaded the private key or
1211 * the private key is stored in external hardware
1213 if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
1214 return (key_sign(id->key, sigp, lenp, data, datalen));
1215 /* load the private key from the file */
1216 if ((prv = load_identity_file(id->filename)) == NULL)
1218 ret = key_sign(prv, sigp, lenp, data, datalen);
1224 sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1227 u_char *blob, *signature;
1228 u_int bloblen, slen;
1234 fp = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
1235 debug3("sign_and_send_pubkey: %s %s", key_type(id->key), fp);
1238 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1239 /* we cannot handle this key */
1240 debug3("sign_and_send_pubkey: cannot handle key");
1243 /* data to be signed */
1245 if (datafellows & SSH_OLD_SESSIONID) {
1246 buffer_append(&b, session_id2, session_id2_len);
1247 skip = session_id2_len;
1249 buffer_put_string(&b, session_id2, session_id2_len);
1250 skip = buffer_len(&b);
1252 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1253 buffer_put_cstring(&b, authctxt->server_user);
1254 buffer_put_cstring(&b,
1255 datafellows & SSH_BUG_PKSERVICE ?
1258 if (datafellows & SSH_BUG_PKAUTH) {
1259 buffer_put_char(&b, have_sig);
1261 buffer_put_cstring(&b, authctxt->method->name);
1262 buffer_put_char(&b, have_sig);
1263 buffer_put_cstring(&b, key_ssh_name(id->key));
1265 buffer_put_string(&b, blob, bloblen);
1267 /* generate signature */
1268 ret = identity_sign(id, &signature, &slen,
1269 buffer_ptr(&b), buffer_len(&b));
1278 if (datafellows & SSH_BUG_PKSERVICE) {
1280 buffer_append(&b, session_id2, session_id2_len);
1281 skip = session_id2_len;
1282 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1283 buffer_put_cstring(&b, authctxt->server_user);
1284 buffer_put_cstring(&b, authctxt->service);
1285 buffer_put_cstring(&b, authctxt->method->name);
1286 buffer_put_char(&b, have_sig);
1287 if (!(datafellows & SSH_BUG_PKAUTH))
1288 buffer_put_cstring(&b, key_ssh_name(id->key));
1289 buffer_put_string(&b, blob, bloblen);
1293 /* append signature */
1294 buffer_put_string(&b, signature, slen);
1297 /* skip session id and packet type */
1298 if (buffer_len(&b) < skip + 1)
1299 fatal("userauth_pubkey: internal error");
1300 buffer_consume(&b, skip + 1);
1302 /* put remaining data from buffer into packet */
1303 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1304 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1312 send_pubkey_test(Authctxt *authctxt, Identity *id)
1315 u_int bloblen, have_sig = 0;
1317 debug3("send_pubkey_test");
1319 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1320 /* we cannot handle this key */
1321 debug3("send_pubkey_test: cannot handle key");
1324 /* register callback for USERAUTH_PK_OK message */
1325 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1327 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1328 packet_put_cstring(authctxt->server_user);
1329 packet_put_cstring(authctxt->service);
1330 packet_put_cstring(authctxt->method->name);
1331 packet_put_char(have_sig);
1332 if (!(datafellows & SSH_BUG_PKAUTH))
1333 packet_put_cstring(key_ssh_name(id->key));
1334 packet_put_string(blob, bloblen);
1341 load_identity_file(char *filename)
1344 char prompt[300], *passphrase;
1345 int perm_ok = 0, quit, i;
1348 if (stat(filename, &st) < 0) {
1349 debug3("no such identity: %s", filename);
1352 private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
1355 if (private == NULL) {
1356 if (options.batch_mode)
1358 snprintf(prompt, sizeof prompt,
1359 "Enter passphrase for key '%.100s': ", filename);
1360 for (i = 0; i < options.number_of_password_prompts; i++) {
1361 passphrase = read_passphrase(prompt, 0);
1362 if (strcmp(passphrase, "") != 0) {
1363 private = key_load_private_type(KEY_UNSPEC,
1364 filename, passphrase, NULL, NULL);
1367 debug2("no passphrase given, try next key");
1370 memset(passphrase, 0, strlen(passphrase));
1372 if (private != NULL || quit)
1374 debug2("bad passphrase given, try again...");
1381 * try keys in the following order:
1382 * 1. agent keys that are found in the config file
1383 * 2. other agent keys
1384 * 3. keys that are only listed in the config file
1387 pubkey_prepare(Authctxt *authctxt)
1390 Idlist agent, files, *preferred;
1392 AuthenticationConnection *ac;
1396 TAILQ_INIT(&agent); /* keys from the agent */
1397 TAILQ_INIT(&files); /* keys from the config file */
1398 preferred = &authctxt->keys;
1399 TAILQ_INIT(preferred); /* preferred order of keys */
1401 /* list of keys stored in the filesystem */
1402 for (i = 0; i < options.num_identity_files; i++) {
1403 key = options.identity_keys[i];
1404 if (key && key->type == KEY_RSA1)
1406 if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1408 options.identity_keys[i] = NULL;
1409 id = xcalloc(1, sizeof(*id));
1411 id->filename = xstrdup(options.identity_files[i]);
1412 TAILQ_INSERT_TAIL(&files, id, next);
1414 /* list of keys supported by the agent */
1415 if ((ac = ssh_get_authentication_connection())) {
1416 for (key = ssh_get_first_identity(ac, &comment, 2);
1418 key = ssh_get_next_identity(ac, &comment, 2)) {
1420 TAILQ_FOREACH(id, &files, next) {
1421 /* agent keys from the config file are preferred */
1422 if (key_equal(key, id->key)) {
1425 TAILQ_REMOVE(&files, id, next);
1426 TAILQ_INSERT_TAIL(preferred, id, next);
1432 if (!found && !options.identities_only) {
1433 id = xcalloc(1, sizeof(*id));
1435 id->filename = comment;
1437 TAILQ_INSERT_TAIL(&agent, id, next);
1440 /* append remaining agent keys */
1441 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1442 TAILQ_REMOVE(&agent, id, next);
1443 TAILQ_INSERT_TAIL(preferred, id, next);
1445 authctxt->agent = ac;
1447 /* append remaining keys from the config file */
1448 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1449 TAILQ_REMOVE(&files, id, next);
1450 TAILQ_INSERT_TAIL(preferred, id, next);
1452 TAILQ_FOREACH(id, preferred, next) {
1453 debug2("key: %s (%p)", id->filename, id->key);
1458 pubkey_cleanup(Authctxt *authctxt)
1462 if (authctxt->agent != NULL)
1463 ssh_close_authentication_connection(authctxt->agent);
1464 for (id = TAILQ_FIRST(&authctxt->keys); id;
1465 id = TAILQ_FIRST(&authctxt->keys)) {
1466 TAILQ_REMOVE(&authctxt->keys, id, next);
1470 xfree(id->filename);
1476 userauth_pubkey(Authctxt *authctxt)
1481 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1484 /* move key to the end of the queue */
1485 TAILQ_REMOVE(&authctxt->keys, id, next);
1486 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1488 * send a test message if we have the public key. for
1489 * encrypted keys we cannot do this and have to load the
1490 * private key instead
1492 if (id->key && id->key->type != KEY_RSA1) {
1493 debug("Offering %s public key: %s", key_type(id->key),
1495 sent = send_pubkey_test(authctxt, id);
1496 } else if (id->key == NULL) {
1497 debug("Trying private key: %s", id->filename);
1498 id->key = load_identity_file(id->filename);
1499 if (id->key != NULL) {
1501 sent = sign_and_send_pubkey(authctxt, id);
1513 * Send userauth request message specifying keyboard-interactive method.
1516 userauth_kbdint(Authctxt *authctxt)
1518 static int attempt = 0;
1520 if (attempt++ >= options.number_of_password_prompts)
1522 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1523 if (attempt > 1 && !authctxt->info_req_seen) {
1524 debug3("userauth_kbdint: disable: no info_req_seen");
1525 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1529 debug2("userauth_kbdint");
1530 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1531 packet_put_cstring(authctxt->server_user);
1532 packet_put_cstring(authctxt->service);
1533 packet_put_cstring(authctxt->method->name);
1534 packet_put_cstring(""); /* lang */
1535 packet_put_cstring(options.kbd_interactive_devices ?
1536 options.kbd_interactive_devices : "");
1539 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1544 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1547 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1549 Authctxt *authctxt = ctxt;
1550 char *name, *inst, *lang, *prompt, *response;
1551 u_int num_prompts, i;
1554 debug2("input_userauth_info_req");
1556 if (authctxt == NULL)
1557 fatal("input_userauth_info_req: no authentication context");
1559 authctxt->info_req_seen = 1;
1561 name = packet_get_string(NULL);
1562 inst = packet_get_string(NULL);
1563 lang = packet_get_string(NULL);
1564 if (strlen(name) > 0)
1566 if (strlen(inst) > 0)
1572 num_prompts = packet_get_int();
1574 * Begin to build info response packet based on prompts requested.
1575 * We commit to providing the correct number of responses, so if
1576 * further on we run into a problem that prevents this, we have to
1577 * be sure and clean this up and send a correct error response.
1579 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1580 packet_put_int(num_prompts);
1582 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1583 for (i = 0; i < num_prompts; i++) {
1584 prompt = packet_get_string(NULL);
1585 echo = packet_get_char();
1587 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1589 packet_put_cstring(response);
1590 memset(response, 0, strlen(response));
1594 packet_check_eom(); /* done with parsing incoming message. */
1596 packet_add_padding(64);
1601 ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1602 u_char *data, u_int datalen)
1607 int to[2], from[2], status, version = 2;
1609 debug2("ssh_keysign called");
1611 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1612 error("ssh_keysign: not installed: %s", strerror(errno));
1615 if (fflush(stdout) != 0)
1616 error("ssh_keysign: fflush: %s", strerror(errno));
1618 error("ssh_keysign: pipe: %s", strerror(errno));
1621 if (pipe(from) < 0) {
1622 error("ssh_keysign: pipe: %s", strerror(errno));
1625 if ((pid = fork()) < 0) {
1626 error("ssh_keysign: fork: %s", strerror(errno));
1630 /* keep the socket on exec */
1631 fcntl(packet_get_connection_in(), F_SETFD, 0);
1632 permanently_drop_suid(getuid());
1634 if (dup2(from[1], STDOUT_FILENO) < 0)
1635 fatal("ssh_keysign: dup2: %s", strerror(errno));
1637 if (dup2(to[0], STDIN_FILENO) < 0)
1638 fatal("ssh_keysign: dup2: %s", strerror(errno));
1641 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1642 fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1649 buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1650 buffer_put_string(&b, data, datalen);
1651 if (ssh_msg_send(to[1], version, &b) == -1)
1652 fatal("ssh_keysign: couldn't send request");
1654 if (ssh_msg_recv(from[0], &b) < 0) {
1655 error("ssh_keysign: no reply");
1662 while (waitpid(pid, &status, 0) < 0)
1666 if (buffer_get_char(&b) != version) {
1667 error("ssh_keysign: bad version");
1671 *sigp = buffer_get_string(&b, lenp);
1678 userauth_hostbased(Authctxt *authctxt)
1680 Key *private = NULL;
1681 Sensitive *sensitive = authctxt->sensitive;
1683 u_char *signature, *blob;
1684 char *chost, *pkalg, *p;
1685 const char *service;
1687 int ok, i, found = 0;
1689 /* check for a useful key */
1690 for (i = 0; i < sensitive->nkeys; i++) {
1691 private = sensitive->keys[i];
1692 if (private && private->type != KEY_RSA1) {
1694 /* we take and free the key */
1695 sensitive->keys[i] = NULL;
1700 debug("No more client hostkeys for hostbased authentication.");
1703 if (key_to_blob(private, &blob, &blen) == 0) {
1707 /* figure out a name for the client host */
1708 p = get_local_name(packet_get_connection_in());
1710 error("userauth_hostbased: cannot get local ipaddr/name");
1715 xasprintf(&chost, "%s.", p);
1716 debug2("userauth_hostbased: chost %s", chost);
1719 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1721 pkalg = xstrdup(key_ssh_name(private));
1723 /* construct data */
1724 buffer_put_string(&b, session_id2, session_id2_len);
1725 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1726 buffer_put_cstring(&b, authctxt->server_user);
1727 buffer_put_cstring(&b, service);
1728 buffer_put_cstring(&b, authctxt->method->name);
1729 buffer_put_cstring(&b, pkalg);
1730 buffer_put_string(&b, blob, blen);
1731 buffer_put_cstring(&b, chost);
1732 buffer_put_cstring(&b, authctxt->local_user);
1736 if (sensitive->external_keysign)
1737 ok = ssh_keysign(private, &signature, &slen,
1738 buffer_ptr(&b), buffer_len(&b));
1740 ok = key_sign(private, &signature, &slen,
1741 buffer_ptr(&b), buffer_len(&b));
1745 error("key_sign failed");
1751 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1752 packet_put_cstring(authctxt->server_user);
1753 packet_put_cstring(authctxt->service);
1754 packet_put_cstring(authctxt->method->name);
1755 packet_put_cstring(pkalg);
1756 packet_put_string(blob, blen);
1757 packet_put_cstring(chost);
1758 packet_put_cstring(authctxt->local_user);
1759 packet_put_string(signature, slen);
1760 memset(signature, 's', slen);
1772 userauth_jpake(Authctxt *authctxt)
1774 struct jpake_ctx *pctx;
1775 u_char *x1_proof, *x2_proof;
1776 u_int x1_proof_len, x2_proof_len;
1777 static int attempt = 0; /* XXX share with userauth_password's? */
1779 if (attempt++ >= options.number_of_password_prompts)
1782 error("Permission denied, please try again.");
1784 if (authctxt->methoddata != NULL)
1785 fatal("%s: authctxt->methoddata already set (%p)",
1786 __func__, authctxt->methoddata);
1788 authctxt->methoddata = pctx = jpake_new();
1791 * Send request immediately, to get the protocol going while
1792 * we do the initial computations.
1794 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1795 packet_put_cstring(authctxt->server_user);
1796 packet_put_cstring(authctxt->service);
1797 packet_put_cstring(authctxt->method->name);
1799 packet_write_wait();
1801 jpake_step1(pctx->grp,
1802 &pctx->client_id, &pctx->client_id_len,
1803 &pctx->x1, &pctx->x2, &pctx->g_x1, &pctx->g_x2,
1804 &x1_proof, &x1_proof_len,
1805 &x2_proof, &x2_proof_len);
1807 JPAKE_DEBUG_CTX((pctx, "step 1 sending in %s", __func__));
1809 packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP1);
1810 packet_put_string(pctx->client_id, pctx->client_id_len);
1811 packet_put_bignum2(pctx->g_x1);
1812 packet_put_bignum2(pctx->g_x2);
1813 packet_put_string(x1_proof, x1_proof_len);
1814 packet_put_string(x2_proof, x2_proof_len);
1817 bzero(x1_proof, x1_proof_len);
1818 bzero(x2_proof, x2_proof_len);
1822 /* Expect step 1 packet from peer */
1823 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1,
1824 input_userauth_jpake_server_step1);
1825 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS,
1826 &input_userauth_success_unexpected);
1832 userauth_jpake_cleanup(Authctxt *authctxt)
1834 debug3("%s: clean up", __func__);
1835 if (authctxt->methoddata != NULL) {
1836 jpake_free(authctxt->methoddata);
1837 authctxt->methoddata = NULL;
1839 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
1843 /* find auth method */
1846 * given auth method name, if configurable options permit this method fill
1847 * in auth_ident field and return true, otherwise return false.
1850 authmethod_is_enabled(Authmethod *method)
1854 /* return false if options indicate this method is disabled */
1855 if (method->enabled == NULL || *method->enabled == 0)
1857 /* return false if batch mode is enabled but method needs interactive mode */
1858 if (method->batch_flag != NULL && *method->batch_flag != 0)
1864 authmethod_lookup(const char *name)
1866 Authmethod *method = NULL;
1868 for (method = authmethods; method->name != NULL; method++)
1869 if (strcmp(name, method->name) == 0)
1871 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1875 /* XXX internal state */
1876 static Authmethod *current = NULL;
1877 static char *supported = NULL;
1878 static char *preferred = NULL;
1881 * Given the authentication method list sent by the server, return the
1882 * next method we should try. If the server initially sends a nil list,
1883 * use a built-in default list.
1886 authmethod_get(char *authlist)
1891 /* Use a suitable default if we're passed a nil list. */
1892 if (authlist == NULL || strlen(authlist) == 0)
1893 authlist = options.preferred_authentications;
1895 if (supported == NULL || strcmp(authlist, supported) != 0) {
1896 debug3("start over, passed a different list %s", authlist);
1897 if (supported != NULL)
1899 supported = xstrdup(authlist);
1900 preferred = options.preferred_authentications;
1901 debug3("preferred %s", preferred);
1903 } else if (current != NULL && authmethod_is_enabled(current))
1907 if ((name = match_list(preferred, supported, &next)) == NULL) {
1908 debug("No more authentication methods to try.");
1913 debug3("authmethod_lookup %s", name);
1914 debug3("remaining preferred: %s", preferred);
1915 if ((current = authmethod_lookup(name)) != NULL &&
1916 authmethod_is_enabled(current)) {
1917 debug3("authmethod_is_enabled %s", name);
1918 debug("Next authentication method: %s", name);
1925 authmethods_get(void)
1927 Authmethod *method = NULL;
1932 for (method = authmethods; method->name != NULL; method++) {
1933 if (authmethod_is_enabled(method)) {
1934 if (buffer_len(&b) > 0)
1935 buffer_append(&b, ",", 1);
1936 buffer_append(&b, method->name, strlen(method->name));
1939 buffer_append(&b, "\0", 1);
1940 list = xstrdup(buffer_ptr(&b));