2 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 RCSID("$OpenBSD: sshconnect2.c,v 1.124 2003/08/25 10:33:33 djm Exp $");
28 #include "openbsd-compat/sys-queue.h"
39 #include "myproposal.h"
40 #include "sshconnect.h"
51 #include "pathnames.h"
58 extern char *client_version_string;
59 extern char *server_version_string;
60 extern Options options;
66 u_char *session_id2 = NULL;
67 u_int session_id2_len = 0;
70 struct sockaddr *xxx_hostaddr;
75 verify_host_key_callback(Key *hostkey)
77 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
78 fatal("Host key verification failed.");
83 ssh_kex2(char *host, struct sockaddr *hostaddr)
88 xxx_hostaddr = hostaddr;
90 if (options.ciphers == (char *)-1) {
91 logit("No valid ciphers for protocol version 2 given, using defaults.");
92 options.ciphers = NULL;
94 if (options.ciphers != NULL) {
95 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
96 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
98 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
99 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
100 myproposal[PROPOSAL_ENC_ALGS_STOC] =
101 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
102 if (options.compression) {
103 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
104 myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none";
106 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
107 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib";
109 if (options.macs != NULL) {
110 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
111 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
113 if (options.hostkeyalgorithms != NULL)
114 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
115 options.hostkeyalgorithms;
117 if (options.rekey_limit)
118 packet_set_rekey_limit(options.rekey_limit);
120 /* start key exchange */
121 kex = kex_setup(myproposal);
122 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
123 kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
124 kex->client_version_string=client_version_string;
125 kex->server_version_string=server_version_string;
126 kex->verify_host_key=&verify_host_key_callback;
130 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
132 session_id2 = kex->session_id;
133 session_id2_len = kex->session_id_len;
136 /* send 1st encrypted/maced/compressed message */
137 packet_start(SSH2_MSG_IGNORE);
138 packet_put_cstring("markus");
148 typedef struct Authctxt Authctxt;
149 typedef struct Authmethod Authmethod;
150 typedef struct identity Identity;
151 typedef struct idlist Idlist;
154 TAILQ_ENTRY(identity) next;
155 AuthenticationConnection *ac; /* set if agent supports key */
156 Key *key; /* public/private key */
157 char *filename; /* comment for agent-only keys */
159 int isprivate; /* key points to the private key */
161 TAILQ_HEAD(idlist, identity);
164 const char *server_user;
165 const char *local_user;
173 AuthenticationConnection *agent;
175 Sensitive *sensitive;
176 /* kbd-interactive */
182 char *name; /* string to compare against server's list */
183 int (*userauth)(Authctxt *authctxt);
184 int *enabled; /* flag in option struct that enables method */
185 int *batch_flag; /* flag in option struct that disables method */
188 void input_userauth_success(int, u_int32_t, void *);
189 void input_userauth_failure(int, u_int32_t, void *);
190 void input_userauth_banner(int, u_int32_t, void *);
191 void input_userauth_error(int, u_int32_t, void *);
192 void input_userauth_info_req(int, u_int32_t, void *);
193 void input_userauth_pk_ok(int, u_int32_t, void *);
194 void input_userauth_passwd_changereq(int, u_int32_t, void *);
196 int userauth_none(Authctxt *);
197 int userauth_pubkey(Authctxt *);
198 int userauth_passwd(Authctxt *);
199 int userauth_kbdint(Authctxt *);
200 int userauth_hostbased(Authctxt *);
201 int userauth_kerberos(Authctxt *);
204 int userauth_gssapi(Authctxt *authctxt);
205 void input_gssapi_response(int type, u_int32_t, void *);
206 void input_gssapi_token(int type, u_int32_t, void *);
207 void input_gssapi_hash(int type, u_int32_t, void *);
208 void input_gssapi_error(int, u_int32_t, void *);
209 void input_gssapi_errtok(int, u_int32_t, void *);
212 void userauth(Authctxt *, char *);
214 static int sign_and_send_pubkey(Authctxt *, Identity *);
215 static void pubkey_prepare(Authctxt *);
216 static void pubkey_cleanup(Authctxt *);
217 static Key *load_identity_file(char *);
219 static Authmethod *authmethod_get(char *authlist);
220 static Authmethod *authmethod_lookup(const char *name);
221 static char *authmethods_get(void);
223 Authmethod authmethods[] = {
227 &options.gss_authentication,
232 &options.hostbased_authentication,
236 &options.pubkey_authentication,
238 {"keyboard-interactive",
240 &options.kbd_interactive_authentication,
241 &options.batch_mode},
244 &options.password_authentication,
245 &options.batch_mode},
250 {NULL, NULL, NULL, NULL}
254 ssh_userauth2(const char *local_user, const char *server_user, char *host,
255 Sensitive *sensitive)
260 if (options.challenge_response_authentication)
261 options.kbd_interactive_authentication = 1;
263 packet_start(SSH2_MSG_SERVICE_REQUEST);
264 packet_put_cstring("ssh-userauth");
266 debug("SSH2_MSG_SERVICE_REQUEST sent");
268 type = packet_read();
269 if (type != SSH2_MSG_SERVICE_ACCEPT)
270 fatal("Server denied authentication request: %d", type);
271 if (packet_remaining() > 0) {
272 char *reply = packet_get_string(NULL);
273 debug2("service_accept: %s", reply);
276 debug2("buggy server: service_accept w/o service");
279 debug("SSH2_MSG_SERVICE_ACCEPT received");
281 if (options.preferred_authentications == NULL)
282 options.preferred_authentications = authmethods_get();
284 /* setup authentication context */
285 memset(&authctxt, 0, sizeof(authctxt));
286 pubkey_prepare(&authctxt);
287 authctxt.server_user = server_user;
288 authctxt.local_user = local_user;
289 authctxt.host = host;
290 authctxt.service = "ssh-connection"; /* service name */
291 authctxt.success = 0;
292 authctxt.method = authmethod_lookup("none");
293 authctxt.authlist = NULL;
294 authctxt.methoddata = NULL;
295 authctxt.sensitive = sensitive;
296 authctxt.info_req_seen = 0;
297 if (authctxt.method == NULL)
298 fatal("ssh_userauth2: internal error: cannot send userauth none request");
300 /* initial userauth request */
301 userauth_none(&authctxt);
303 dispatch_init(&input_userauth_error);
304 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
305 dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
306 dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
307 dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
309 pubkey_cleanup(&authctxt);
310 dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
312 debug("Authentication succeeded (%s).", authctxt.method->name);
316 userauth(Authctxt *authctxt, char *authlist)
318 if (authctxt->methoddata) {
319 xfree(authctxt->methoddata);
320 authctxt->methoddata = NULL;
322 if (authlist == NULL) {
323 authlist = authctxt->authlist;
325 if (authctxt->authlist)
326 xfree(authctxt->authlist);
327 authctxt->authlist = authlist;
330 Authmethod *method = authmethod_get(authlist);
332 fatal("Permission denied (%s).", authlist);
333 authctxt->method = method;
335 /* reset the per method handler */
336 dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
337 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
339 /* and try new method */
340 if (method->userauth(authctxt) != 0) {
341 debug2("we sent a %s packet, wait for reply", method->name);
344 debug2("we did not send a packet, disable method");
345 method->enabled = NULL;
351 input_userauth_error(int type, u_int32_t seq, void *ctxt)
353 fatal("input_userauth_error: bad message during authentication: "
358 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
361 debug3("input_userauth_banner");
362 msg = packet_get_string(NULL);
363 lang = packet_get_string(NULL);
370 input_userauth_success(int type, u_int32_t seq, void *ctxt)
372 Authctxt *authctxt = ctxt;
373 if (authctxt == NULL)
374 fatal("input_userauth_success: no authentication context");
375 if (authctxt->authlist)
376 xfree(authctxt->authlist);
377 if (authctxt->methoddata)
378 xfree(authctxt->methoddata);
379 authctxt->success = 1; /* break out */
383 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
385 Authctxt *authctxt = ctxt;
386 char *authlist = NULL;
389 if (authctxt == NULL)
390 fatal("input_userauth_failure: no authentication context");
392 authlist = packet_get_string(NULL);
393 partial = packet_get_char();
397 logit("Authenticated with partial success.");
398 debug("Authentications that can continue: %s", authlist);
400 userauth(authctxt, authlist);
403 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
405 Authctxt *authctxt = ctxt;
409 int pktype, sent = 0;
414 if (authctxt == NULL)
415 fatal("input_userauth_pk_ok: no authentication context");
416 if (datafellows & SSH_BUG_PKOK) {
417 /* this is similar to SSH_BUG_PKAUTH */
418 debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
419 pkblob = packet_get_string(&blen);
421 buffer_append(&b, pkblob, blen);
422 pkalg = buffer_get_string(&b, &alen);
425 pkalg = packet_get_string(&alen);
426 pkblob = packet_get_string(&blen);
430 debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
432 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
433 debug("unknown pkalg %s", pkalg);
436 if ((key = key_from_blob(pkblob, blen)) == NULL) {
437 debug("no key from blob. pkalg %s", pkalg);
440 if (key->type != pktype) {
441 error("input_userauth_pk_ok: type mismatch "
442 "for decoded key (received %d, expected %d)",
446 fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
447 debug2("input_userauth_pk_ok: fp %s", fp);
450 TAILQ_FOREACH(id, &authctxt->keys, next) {
451 if (key_equal(key, id->key)) {
452 sent = sign_and_send_pubkey(authctxt, id);
462 /* try another method if we did not send a packet */
464 userauth(authctxt, NULL);
469 userauth_gssapi(Authctxt *authctxt)
471 Gssctxt *gssctxt = NULL;
472 static gss_OID_set supported = NULL;
477 /* Try one GSSAPI method at a time, rather than sending them all at
480 if (supported == NULL)
481 gss_indicate_mechs(&min, &supported);
483 /* Check to see if the mechanism is usable before we offer it */
484 while (mech<supported->count && !ok) {
486 ssh_gssapi_delete_ctx(&gssctxt);
487 ssh_gssapi_build_ctx(&gssctxt);
488 ssh_gssapi_set_oid(gssctxt, &supported->elements[mech]);
490 /* My DER encoding requires length<128 */
491 if (supported->elements[mech].length < 128 &&
492 !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
494 ok = 1; /* Mechanism works */
502 authctxt->methoddata=(void *)gssctxt;
504 packet_start(SSH2_MSG_USERAUTH_REQUEST);
505 packet_put_cstring(authctxt->server_user);
506 packet_put_cstring(authctxt->service);
507 packet_put_cstring(authctxt->method->name);
511 /* Some servers encode the OID incorrectly (as we used to) */
512 if (datafellows & SSH_BUG_GSSAPI_BER) {
513 packet_put_string(supported->elements[mech].elements,
514 supported->elements[mech].length);
516 packet_put_int((supported->elements[mech].length)+2);
517 packet_put_char(SSH_GSS_OIDTYPE);
518 packet_put_char(supported->elements[mech].length);
519 packet_put_raw(supported->elements[mech].elements,
520 supported->elements[mech].length);
525 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
526 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
527 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
528 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
530 mech++; /* Move along to next candidate */
536 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
538 Authctxt *authctxt = ctxt;
540 OM_uint32 status, ms;
543 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
545 if (authctxt == NULL)
546 fatal("input_gssapi_response: no authentication context");
547 gssctxt = authctxt->methoddata;
550 oidv = packet_get_string(&oidlen);
552 if (datafellows & SSH_BUG_GSSAPI_BER) {
553 if (!ssh_gssapi_check_oid(gssctxt, oidv, oidlen))
554 fatal("Server returned different OID than expected");
556 if(oidv[0] != SSH_GSS_OIDTYPE || oidv[1] != oidlen-2) {
557 debug("Badly encoded mechanism OID received");
558 userauth(authctxt, NULL);
562 if (!ssh_gssapi_check_oid(gssctxt, oidv+2, oidlen-2))
563 fatal("Server returned different OID than expected");
570 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
571 GSS_C_NO_BUFFER, &send_tok, NULL);
572 if (GSS_ERROR(status)) {
573 if (send_tok.length > 0) {
574 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
575 packet_put_string(send_tok.value, send_tok.length);
577 gss_release_buffer(&ms, &send_tok);
579 /* Start again with next method on list */
580 debug("Trying to start again");
581 userauth(authctxt, NULL);
585 /* We must have data to send */
586 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
587 packet_put_string(send_tok.value, send_tok.length);
589 gss_release_buffer(&ms, &send_tok);
593 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
595 Authctxt *authctxt = ctxt;
597 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
598 gss_buffer_desc recv_tok;
599 OM_uint32 status, ms;
602 if (authctxt == NULL)
603 fatal("input_gssapi_response: no authentication context");
604 gssctxt = authctxt->methoddata;
606 recv_tok.value = packet_get_string(&slen);
607 recv_tok.length = slen; /* safe typecast */
611 status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
612 &recv_tok, &send_tok, NULL);
614 xfree(recv_tok.value);
616 if (GSS_ERROR(status)) {
617 if (send_tok.length > 0) {
618 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
619 packet_put_string(send_tok.value, send_tok.length);
621 gss_release_buffer(&ms, &send_tok);
623 /* Start again with the next method in the list */
624 userauth(authctxt, NULL);
628 if (send_tok.length > 0) {
629 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
630 packet_put_string(send_tok.value, send_tok.length);
632 gss_release_buffer(&ms, &send_tok);
635 if (status == GSS_S_COMPLETE) {
636 /* If that succeeded, send a exchange complete message */
637 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
643 input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
645 Authctxt *authctxt = ctxt;
647 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
648 gss_buffer_desc recv_tok;
649 OM_uint32 status, ms;
652 if (authctxt == NULL)
653 fatal("input_gssapi_response: no authentication context");
654 gssctxt = authctxt->methoddata;
656 recv_tok.value = packet_get_string(&len);
657 recv_tok.length = len;
661 /* Stick it into GSSAPI and see what it says */
662 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
663 &recv_tok, &send_tok, NULL);
665 xfree(recv_tok.value);
666 gss_release_buffer(&ms, &send_tok);
668 /* Server will be returning a failed packet after this one */
672 input_gssapi_error(int type, u_int32_t plen, void *ctxt)
678 maj=packet_get_int();
679 min=packet_get_int();
680 msg=packet_get_string(NULL);
681 lang=packet_get_string(NULL);
685 debug("Server GSSAPI Error:\n%s\n", msg);
692 userauth_none(Authctxt *authctxt)
694 /* initial userauth request */
695 packet_start(SSH2_MSG_USERAUTH_REQUEST);
696 packet_put_cstring(authctxt->server_user);
697 packet_put_cstring(authctxt->service);
698 packet_put_cstring(authctxt->method->name);
704 userauth_passwd(Authctxt *authctxt)
706 static int attempt = 0;
710 if (attempt++ >= options.number_of_password_prompts)
714 error("Permission denied, please try again.");
716 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
717 authctxt->server_user, authctxt->host);
718 password = read_passphrase(prompt, 0);
719 packet_start(SSH2_MSG_USERAUTH_REQUEST);
720 packet_put_cstring(authctxt->server_user);
721 packet_put_cstring(authctxt->service);
722 packet_put_cstring(authctxt->method->name);
724 packet_put_cstring(password);
725 memset(password, 0, strlen(password));
727 packet_add_padding(64);
730 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
731 &input_userauth_passwd_changereq);
736 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
739 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
741 Authctxt *authctxt = ctxt;
742 char *info, *lang, *password = NULL, *retype = NULL;
745 debug2("input_userauth_passwd_changereq");
747 if (authctxt == NULL)
748 fatal("input_userauth_passwd_changereq: "
749 "no authentication context");
751 info = packet_get_string(NULL);
752 lang = packet_get_string(NULL);
753 if (strlen(info) > 0)
757 packet_start(SSH2_MSG_USERAUTH_REQUEST);
758 packet_put_cstring(authctxt->server_user);
759 packet_put_cstring(authctxt->service);
760 packet_put_cstring(authctxt->method->name);
761 packet_put_char(1); /* additional info */
762 snprintf(prompt, sizeof(prompt),
763 "Enter %.30s@%.128s's old password: ",
764 authctxt->server_user, authctxt->host);
765 password = read_passphrase(prompt, 0);
766 packet_put_cstring(password);
767 memset(password, 0, strlen(password));
770 while (password == NULL) {
771 snprintf(prompt, sizeof(prompt),
772 "Enter %.30s@%.128s's new password: ",
773 authctxt->server_user, authctxt->host);
774 password = read_passphrase(prompt, RP_ALLOW_EOF);
775 if (password == NULL) {
779 snprintf(prompt, sizeof(prompt),
780 "Retype %.30s@%.128s's new password: ",
781 authctxt->server_user, authctxt->host);
782 retype = read_passphrase(prompt, 0);
783 if (strcmp(password, retype) != 0) {
784 memset(password, 0, strlen(password));
786 logit("Mismatch; try again, EOF to quit.");
789 memset(retype, 0, strlen(retype));
792 packet_put_cstring(password);
793 memset(password, 0, strlen(password));
795 packet_add_padding(64);
798 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
799 &input_userauth_passwd_changereq);
803 identity_sign(Identity *id, u_char **sigp, u_int *lenp,
804 u_char *data, u_int datalen)
809 /* the agent supports this key */
811 return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
814 * we have already loaded the private key or
815 * the private key is stored in external hardware
817 if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
818 return (key_sign(id->key, sigp, lenp, data, datalen));
819 /* load the private key from the file */
820 if ((prv = load_identity_file(id->filename)) == NULL)
822 ret = key_sign(prv, sigp, lenp, data, datalen);
828 sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
831 u_char *blob, *signature;
837 debug3("sign_and_send_pubkey");
839 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
840 /* we cannot handle this key */
841 debug3("sign_and_send_pubkey: cannot handle key");
844 /* data to be signed */
846 if (datafellows & SSH_OLD_SESSIONID) {
847 buffer_append(&b, session_id2, session_id2_len);
848 skip = session_id2_len;
850 buffer_put_string(&b, session_id2, session_id2_len);
851 skip = buffer_len(&b);
853 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
854 buffer_put_cstring(&b, authctxt->server_user);
855 buffer_put_cstring(&b,
856 datafellows & SSH_BUG_PKSERVICE ?
859 if (datafellows & SSH_BUG_PKAUTH) {
860 buffer_put_char(&b, have_sig);
862 buffer_put_cstring(&b, authctxt->method->name);
863 buffer_put_char(&b, have_sig);
864 buffer_put_cstring(&b, key_ssh_name(id->key));
866 buffer_put_string(&b, blob, bloblen);
868 /* generate signature */
869 ret = identity_sign(id, &signature, &slen,
870 buffer_ptr(&b), buffer_len(&b));
879 if (datafellows & SSH_BUG_PKSERVICE) {
881 buffer_append(&b, session_id2, session_id2_len);
882 skip = session_id2_len;
883 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
884 buffer_put_cstring(&b, authctxt->server_user);
885 buffer_put_cstring(&b, authctxt->service);
886 buffer_put_cstring(&b, authctxt->method->name);
887 buffer_put_char(&b, have_sig);
888 if (!(datafellows & SSH_BUG_PKAUTH))
889 buffer_put_cstring(&b, key_ssh_name(id->key));
890 buffer_put_string(&b, blob, bloblen);
894 /* append signature */
895 buffer_put_string(&b, signature, slen);
898 /* skip session id and packet type */
899 if (buffer_len(&b) < skip + 1)
900 fatal("userauth_pubkey: internal error");
901 buffer_consume(&b, skip + 1);
903 /* put remaining data from buffer into packet */
904 packet_start(SSH2_MSG_USERAUTH_REQUEST);
905 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
913 send_pubkey_test(Authctxt *authctxt, Identity *id)
916 u_int bloblen, have_sig = 0;
918 debug3("send_pubkey_test");
920 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
921 /* we cannot handle this key */
922 debug3("send_pubkey_test: cannot handle key");
925 /* register callback for USERAUTH_PK_OK message */
926 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
928 packet_start(SSH2_MSG_USERAUTH_REQUEST);
929 packet_put_cstring(authctxt->server_user);
930 packet_put_cstring(authctxt->service);
931 packet_put_cstring(authctxt->method->name);
932 packet_put_char(have_sig);
933 if (!(datafellows & SSH_BUG_PKAUTH))
934 packet_put_cstring(key_ssh_name(id->key));
935 packet_put_string(blob, bloblen);
942 load_identity_file(char *filename)
945 char prompt[300], *passphrase;
949 if (stat(filename, &st) < 0) {
950 debug3("no such identity: %s", filename);
953 private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
954 if (private == NULL) {
955 if (options.batch_mode)
957 snprintf(prompt, sizeof prompt,
958 "Enter passphrase for key '%.100s': ", filename);
959 for (i = 0; i < options.number_of_password_prompts; i++) {
960 passphrase = read_passphrase(prompt, 0);
961 if (strcmp(passphrase, "") != 0) {
962 private = key_load_private_type(KEY_UNSPEC, filename,
966 debug2("no passphrase given, try next key");
969 memset(passphrase, 0, strlen(passphrase));
971 if (private != NULL || quit)
973 debug2("bad passphrase given, try again...");
980 * try keys in the following order:
981 * 1. agent keys that are found in the config file
982 * 2. other agent keys
983 * 3. keys that are only listed in the config file
986 pubkey_prepare(Authctxt *authctxt)
989 Idlist agent, files, *preferred;
991 AuthenticationConnection *ac;
995 TAILQ_INIT(&agent); /* keys from the agent */
996 TAILQ_INIT(&files); /* keys from the config file */
997 preferred = &authctxt->keys;
998 TAILQ_INIT(preferred); /* preferred order of keys */
1000 /* list of keys stored in the filesystem */
1001 for (i = 0; i < options.num_identity_files; i++) {
1002 key = options.identity_keys[i];
1003 if (key && key->type == KEY_RSA1)
1005 options.identity_keys[i] = NULL;
1006 id = xmalloc(sizeof(*id));
1007 memset(id, 0, sizeof(*id));
1009 id->filename = xstrdup(options.identity_files[i]);
1010 TAILQ_INSERT_TAIL(&files, id, next);
1012 /* list of keys supported by the agent */
1013 if ((ac = ssh_get_authentication_connection())) {
1014 for (key = ssh_get_first_identity(ac, &comment, 2);
1016 key = ssh_get_next_identity(ac, &comment, 2)) {
1018 TAILQ_FOREACH(id, &files, next) {
1019 /* agent keys from the config file are preferred */
1020 if (key_equal(key, id->key)) {
1023 TAILQ_REMOVE(&files, id, next);
1024 TAILQ_INSERT_TAIL(preferred, id, next);
1031 id = xmalloc(sizeof(*id));
1032 memset(id, 0, sizeof(*id));
1034 id->filename = comment;
1036 TAILQ_INSERT_TAIL(&agent, id, next);
1039 /* append remaining agent keys */
1040 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1041 TAILQ_REMOVE(&agent, id, next);
1042 TAILQ_INSERT_TAIL(preferred, id, next);
1044 authctxt->agent = ac;
1046 /* append remaining keys from the config file */
1047 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1048 TAILQ_REMOVE(&files, id, next);
1049 TAILQ_INSERT_TAIL(preferred, id, next);
1051 TAILQ_FOREACH(id, preferred, next) {
1052 debug2("key: %s (%p)", id->filename, id->key);
1057 pubkey_cleanup(Authctxt *authctxt)
1061 if (authctxt->agent != NULL)
1062 ssh_close_authentication_connection(authctxt->agent);
1063 for (id = TAILQ_FIRST(&authctxt->keys); id;
1064 id = TAILQ_FIRST(&authctxt->keys)) {
1065 TAILQ_REMOVE(&authctxt->keys, id, next);
1069 xfree(id->filename);
1075 userauth_pubkey(Authctxt *authctxt)
1080 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1083 TAILQ_REMOVE(&authctxt->keys, id, next);
1084 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1086 * send a test message if we have the public key. for
1087 * encrypted keys we cannot do this and have to load the
1088 * private key instead
1090 if (id->key && id->key->type != KEY_RSA1) {
1091 debug("Offering public key: %s", id->filename);
1092 sent = send_pubkey_test(authctxt, id);
1093 } else if (id->key == NULL) {
1094 debug("Trying private key: %s", id->filename);
1095 id->key = load_identity_file(id->filename);
1096 if (id->key != NULL) {
1098 sent = sign_and_send_pubkey(authctxt, id);
1110 * Send userauth request message specifying keyboard-interactive method.
1113 userauth_kbdint(Authctxt *authctxt)
1115 static int attempt = 0;
1117 if (attempt++ >= options.number_of_password_prompts)
1119 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1120 if (attempt > 1 && !authctxt->info_req_seen) {
1121 debug3("userauth_kbdint: disable: no info_req_seen");
1122 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1126 debug2("userauth_kbdint");
1127 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1128 packet_put_cstring(authctxt->server_user);
1129 packet_put_cstring(authctxt->service);
1130 packet_put_cstring(authctxt->method->name);
1131 packet_put_cstring(""); /* lang */
1132 packet_put_cstring(options.kbd_interactive_devices ?
1133 options.kbd_interactive_devices : "");
1136 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1141 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1144 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1146 Authctxt *authctxt = ctxt;
1147 char *name, *inst, *lang, *prompt, *response;
1148 u_int num_prompts, i;
1151 debug2("input_userauth_info_req");
1153 if (authctxt == NULL)
1154 fatal("input_userauth_info_req: no authentication context");
1156 authctxt->info_req_seen = 1;
1158 name = packet_get_string(NULL);
1159 inst = packet_get_string(NULL);
1160 lang = packet_get_string(NULL);
1161 if (strlen(name) > 0)
1163 if (strlen(inst) > 0)
1169 num_prompts = packet_get_int();
1171 * Begin to build info response packet based on prompts requested.
1172 * We commit to providing the correct number of responses, so if
1173 * further on we run into a problem that prevents this, we have to
1174 * be sure and clean this up and send a correct error response.
1176 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1177 packet_put_int(num_prompts);
1179 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1180 for (i = 0; i < num_prompts; i++) {
1181 prompt = packet_get_string(NULL);
1182 echo = packet_get_char();
1184 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1186 packet_put_cstring(response);
1187 memset(response, 0, strlen(response));
1191 packet_check_eom(); /* done with parsing incoming message. */
1193 packet_add_padding(64);
1198 ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1199 u_char *data, u_int datalen)
1204 int to[2], from[2], status, version = 2;
1206 debug2("ssh_keysign called");
1208 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1209 error("ssh_keysign: no installed: %s", strerror(errno));
1212 if (fflush(stdout) != 0)
1213 error("ssh_keysign: fflush: %s", strerror(errno));
1215 error("ssh_keysign: pipe: %s", strerror(errno));
1218 if (pipe(from) < 0) {
1219 error("ssh_keysign: pipe: %s", strerror(errno));
1222 if ((pid = fork()) < 0) {
1223 error("ssh_keysign: fork: %s", strerror(errno));
1230 if (dup2(from[1], STDOUT_FILENO) < 0)
1231 fatal("ssh_keysign: dup2: %s", strerror(errno));
1233 if (dup2(to[0], STDIN_FILENO) < 0)
1234 fatal("ssh_keysign: dup2: %s", strerror(errno));
1237 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1238 fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1245 buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1246 buffer_put_string(&b, data, datalen);
1247 ssh_msg_send(to[1], version, &b);
1249 if (ssh_msg_recv(from[0], &b) < 0) {
1250 error("ssh_keysign: no reply");
1257 while (waitpid(pid, &status, 0) < 0)
1261 if (buffer_get_char(&b) != version) {
1262 error("ssh_keysign: bad version");
1266 *sigp = buffer_get_string(&b, lenp);
1273 userauth_hostbased(Authctxt *authctxt)
1275 Key *private = NULL;
1276 Sensitive *sensitive = authctxt->sensitive;
1278 u_char *signature, *blob;
1279 char *chost, *pkalg, *p;
1280 const char *service;
1282 int ok, i, len, found = 0;
1284 /* check for a useful key */
1285 for (i = 0; i < sensitive->nkeys; i++) {
1286 private = sensitive->keys[i];
1287 if (private && private->type != KEY_RSA1) {
1289 /* we take and free the key */
1290 sensitive->keys[i] = NULL;
1295 debug("No more client hostkeys for hostbased authentication.");
1298 if (key_to_blob(private, &blob, &blen) == 0) {
1302 /* figure out a name for the client host */
1303 p = get_local_name(packet_get_connection_in());
1305 error("userauth_hostbased: cannot get local ipaddr/name");
1309 len = strlen(p) + 2;
1310 chost = xmalloc(len);
1311 strlcpy(chost, p, len);
1312 strlcat(chost, ".", len);
1313 debug2("userauth_hostbased: chost %s", chost);
1316 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1318 pkalg = xstrdup(key_ssh_name(private));
1320 /* construct data */
1321 buffer_put_string(&b, session_id2, session_id2_len);
1322 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1323 buffer_put_cstring(&b, authctxt->server_user);
1324 buffer_put_cstring(&b, service);
1325 buffer_put_cstring(&b, authctxt->method->name);
1326 buffer_put_cstring(&b, pkalg);
1327 buffer_put_string(&b, blob, blen);
1328 buffer_put_cstring(&b, chost);
1329 buffer_put_cstring(&b, authctxt->local_user);
1333 if (sensitive->external_keysign)
1334 ok = ssh_keysign(private, &signature, &slen,
1335 buffer_ptr(&b), buffer_len(&b));
1337 ok = key_sign(private, &signature, &slen,
1338 buffer_ptr(&b), buffer_len(&b));
1342 error("key_sign failed");
1347 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1348 packet_put_cstring(authctxt->server_user);
1349 packet_put_cstring(authctxt->service);
1350 packet_put_cstring(authctxt->method->name);
1351 packet_put_cstring(pkalg);
1352 packet_put_string(blob, blen);
1353 packet_put_cstring(chost);
1354 packet_put_cstring(authctxt->local_user);
1355 packet_put_string(signature, slen);
1356 memset(signature, 's', slen);
1365 /* find auth method */
1368 * given auth method name, if configurable options permit this method fill
1369 * in auth_ident field and return true, otherwise return false.
1372 authmethod_is_enabled(Authmethod *method)
1376 /* return false if options indicate this method is disabled */
1377 if (method->enabled == NULL || *method->enabled == 0)
1379 /* return false if batch mode is enabled but method needs interactive mode */
1380 if (method->batch_flag != NULL && *method->batch_flag != 0)
1386 authmethod_lookup(const char *name)
1388 Authmethod *method = NULL;
1390 for (method = authmethods; method->name != NULL; method++)
1391 if (strcmp(name, method->name) == 0)
1393 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1397 /* XXX internal state */
1398 static Authmethod *current = NULL;
1399 static char *supported = NULL;
1400 static char *preferred = NULL;
1403 * Given the authentication method list sent by the server, return the
1404 * next method we should try. If the server initially sends a nil list,
1405 * use a built-in default list.
1408 authmethod_get(char *authlist)
1413 /* Use a suitable default if we're passed a nil list. */
1414 if (authlist == NULL || strlen(authlist) == 0)
1415 authlist = options.preferred_authentications;
1417 if (supported == NULL || strcmp(authlist, supported) != 0) {
1418 debug3("start over, passed a different list %s", authlist);
1419 if (supported != NULL)
1421 supported = xstrdup(authlist);
1422 preferred = options.preferred_authentications;
1423 debug3("preferred %s", preferred);
1425 } else if (current != NULL && authmethod_is_enabled(current))
1429 if ((name = match_list(preferred, supported, &next)) == NULL) {
1430 debug("No more authentication methods to try.");
1435 debug3("authmethod_lookup %s", name);
1436 debug3("remaining preferred: %s", preferred);
1437 if ((current = authmethod_lookup(name)) != NULL &&
1438 authmethod_is_enabled(current)) {
1439 debug3("authmethod_is_enabled %s", name);
1440 debug("Next authentication method: %s", name);
1447 authmethods_get(void)
1449 Authmethod *method = NULL;
1454 for (method = authmethods; method->name != NULL; method++) {
1455 if (authmethod_is_enabled(method)) {
1456 if (buffer_len(&b) > 0)
1457 buffer_append(&b, ",", 1);
1458 buffer_append(&b, method->name, strlen(method->name));
1461 buffer_append(&b, "\0", 1);
1462 list = xstrdup(buffer_ptr(&b));