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 1.99 2002/03/26 15:58:46 markus Exp $");
37 #include "myproposal.h"
38 #include "sshconnect.h"
50 extern char *client_version_string;
51 extern char *server_version_string;
52 extern Options options;
58 u_char *session_id2 = NULL;
59 int session_id2_len = 0;
62 struct sockaddr *xxx_hostaddr;
67 verify_host_key_callback(Key *hostkey)
69 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
70 fatal("Host key verification failed.");
75 ssh_kex2(char *host, struct sockaddr *hostaddr)
80 xxx_hostaddr = hostaddr;
82 if (options.ciphers == (char *)-1) {
83 log("No valid ciphers for protocol version 2 given, using defaults.");
84 options.ciphers = NULL;
86 if (options.ciphers != NULL) {
87 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
88 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
90 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
91 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
92 myproposal[PROPOSAL_ENC_ALGS_STOC] =
93 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
94 if (options.compression) {
95 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
96 myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib";
98 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
99 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
101 if (options.macs != NULL) {
102 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
103 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
105 if (options.hostkeyalgorithms != NULL)
106 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
107 options.hostkeyalgorithms;
109 /* start key exchange */
110 kex = kex_setup(myproposal);
111 kex->client_version_string=client_version_string;
112 kex->server_version_string=server_version_string;
113 kex->verify_host_key=&verify_host_key_callback;
117 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
119 session_id2 = kex->session_id;
120 session_id2_len = kex->session_id_len;
123 /* send 1st encrypted/maced/compressed message */
124 packet_start(SSH2_MSG_IGNORE);
125 packet_put_cstring("markus");
129 debug("done: ssh_kex2.");
136 typedef struct Authctxt Authctxt;
137 typedef struct Authmethod Authmethod;
139 typedef int sign_cb_fn(
140 Authctxt *authctxt, Key *key,
141 u_char **sigp, u_int *lenp, u_char *data, u_int datalen);
144 const char *server_user;
145 const char *local_user;
153 sign_cb_fn *last_key_sign;
155 AuthenticationConnection *agent;
159 /* kbd-interactive */
163 char *name; /* string to compare against server's list */
164 int (*userauth)(Authctxt *authctxt);
165 int *enabled; /* flag in option struct that enables method */
166 int *batch_flag; /* flag in option struct that disables method */
169 void input_userauth_success(int, u_int32_t, void *);
170 void input_userauth_failure(int, u_int32_t, void *);
171 void input_userauth_banner(int, u_int32_t, void *);
172 void input_userauth_error(int, u_int32_t, void *);
173 void input_userauth_info_req(int, u_int32_t, void *);
174 void input_userauth_pk_ok(int, u_int32_t, void *);
175 void input_userauth_passwd_changereq(int, u_int32_t, void *);
177 int userauth_none(Authctxt *);
178 int userauth_pubkey(Authctxt *);
179 int userauth_passwd(Authctxt *);
180 int userauth_kbdint(Authctxt *);
181 int userauth_hostbased(Authctxt *);
183 void userauth(Authctxt *, char *);
185 static int sign_and_send_pubkey(Authctxt *, Key *, sign_cb_fn *);
186 static void clear_auth_state(Authctxt *);
188 static Authmethod *authmethod_get(char *authlist);
189 static Authmethod *authmethod_lookup(const char *name);
190 static char *authmethods_get(void);
192 Authmethod authmethods[] = {
195 &options.hostbased_authentication,
199 &options.pubkey_authentication,
201 {"keyboard-interactive",
203 &options.kbd_interactive_authentication,
204 &options.batch_mode},
207 &options.password_authentication,
208 &options.batch_mode},
213 {NULL, NULL, NULL, NULL}
217 ssh_userauth2(const char *local_user, const char *server_user, char *host,
218 Key **keys, int nkeys)
223 if (options.challenge_response_authentication)
224 options.kbd_interactive_authentication = 1;
226 debug("send SSH2_MSG_SERVICE_REQUEST");
227 packet_start(SSH2_MSG_SERVICE_REQUEST);
228 packet_put_cstring("ssh-userauth");
231 type = packet_read();
232 if (type != SSH2_MSG_SERVICE_ACCEPT) {
233 fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type);
235 if (packet_remaining() > 0) {
236 char *reply = packet_get_string(NULL);
237 debug("service_accept: %s", reply);
240 debug("buggy server: service_accept w/o service");
243 debug("got SSH2_MSG_SERVICE_ACCEPT");
245 if (options.preferred_authentications == NULL)
246 options.preferred_authentications = authmethods_get();
248 /* setup authentication context */
249 memset(&authctxt, 0, sizeof(authctxt));
250 authctxt.agent = ssh_get_authentication_connection();
251 authctxt.server_user = server_user;
252 authctxt.local_user = local_user;
253 authctxt.host = host;
254 authctxt.service = "ssh-connection"; /* service name */
255 authctxt.success = 0;
256 authctxt.method = authmethod_lookup("none");
257 authctxt.authlist = NULL;
258 authctxt.keys = keys;
259 authctxt.nkeys = nkeys;
260 authctxt.info_req_seen = 0;
261 if (authctxt.method == NULL)
262 fatal("ssh_userauth2: internal error: cannot send userauth none request");
264 /* initial userauth request */
265 userauth_none(&authctxt);
267 dispatch_init(&input_userauth_error);
268 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
269 dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
270 dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
271 dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
273 if (authctxt.agent != NULL)
274 ssh_close_authentication_connection(authctxt.agent);
276 debug("ssh-userauth2 successful: method %s", authctxt.method->name);
279 userauth(Authctxt *authctxt, char *authlist)
281 if (authlist == NULL) {
282 authlist = authctxt->authlist;
284 if (authctxt->authlist)
285 xfree(authctxt->authlist);
286 authctxt->authlist = authlist;
289 Authmethod *method = authmethod_get(authlist);
291 fatal("Permission denied (%s).", authlist);
292 authctxt->method = method;
293 if (method->userauth(authctxt) != 0) {
294 debug2("we sent a %s packet, wait for reply", method->name);
297 debug2("we did not send a packet, disable method");
298 method->enabled = NULL;
303 input_userauth_error(int type, u_int32_t seq, void *ctxt)
305 fatal("input_userauth_error: bad message during authentication: "
309 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
312 debug3("input_userauth_banner");
313 msg = packet_get_string(NULL);
314 lang = packet_get_string(NULL);
315 fprintf(stderr, "%s", msg);
320 input_userauth_success(int type, u_int32_t seq, void *ctxt)
322 Authctxt *authctxt = ctxt;
323 if (authctxt == NULL)
324 fatal("input_userauth_success: no authentication context");
325 if (authctxt->authlist)
326 xfree(authctxt->authlist);
327 clear_auth_state(authctxt);
328 authctxt->success = 1; /* break out */
331 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
333 Authctxt *authctxt = ctxt;
334 char *authlist = NULL;
337 if (authctxt == NULL)
338 fatal("input_userauth_failure: no authentication context");
340 authlist = packet_get_string(NULL);
341 partial = packet_get_char();
345 log("Authenticated with partial success.");
346 debug("authentications that can continue: %s", authlist);
348 clear_auth_state(authctxt);
349 userauth(authctxt, authlist);
352 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
354 Authctxt *authctxt = ctxt;
357 int pktype, sent = 0;
362 if (authctxt == NULL)
363 fatal("input_userauth_pk_ok: no authentication context");
364 if (datafellows & SSH_BUG_PKOK) {
365 /* this is similar to SSH_BUG_PKAUTH */
366 debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
367 pkblob = packet_get_string(&blen);
369 buffer_append(&b, pkblob, blen);
370 pkalg = buffer_get_string(&b, &alen);
373 pkalg = packet_get_string(&alen);
374 pkblob = packet_get_string(&blen);
378 debug("input_userauth_pk_ok: pkalg %s blen %d lastkey %p hint %d",
379 pkalg, blen, authctxt->last_key, authctxt->last_key_hint);
382 if (authctxt->last_key == NULL ||
383 authctxt->last_key_sign == NULL) {
384 debug("no last key or no sign cb");
387 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
388 debug("unknown pkalg %s", pkalg);
391 if ((key = key_from_blob(pkblob, blen)) == NULL) {
392 debug("no key from blob. pkalg %s", pkalg);
395 if (key->type != pktype) {
396 error("input_userauth_pk_ok: type mismatch "
397 "for decoded key (received %d, expected %d)",
401 fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
402 debug2("input_userauth_pk_ok: fp %s", fp);
404 if (!key_equal(key, authctxt->last_key)) {
405 debug("key != last_key");
408 sent = sign_and_send_pubkey(authctxt, key,
409 authctxt->last_key_sign);
418 clear_auth_state(authctxt);
419 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL);
421 /* try another method if we did not send a packet*/
423 userauth(authctxt, NULL);
428 userauth_none(Authctxt *authctxt)
430 /* initial userauth request */
431 packet_start(SSH2_MSG_USERAUTH_REQUEST);
432 packet_put_cstring(authctxt->server_user);
433 packet_put_cstring(authctxt->service);
434 packet_put_cstring(authctxt->method->name);
440 userauth_passwd(Authctxt *authctxt)
442 static int attempt = 0;
446 if (attempt++ >= options.number_of_password_prompts)
450 error("Permission denied, please try again.");
452 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
453 authctxt->server_user, authctxt->host);
454 password = read_passphrase(prompt, 0);
455 packet_start(SSH2_MSG_USERAUTH_REQUEST);
456 packet_put_cstring(authctxt->server_user);
457 packet_put_cstring(authctxt->service);
458 packet_put_cstring(authctxt->method->name);
460 packet_put_cstring(password);
461 memset(password, 0, strlen(password));
463 packet_add_padding(64);
466 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
467 &input_userauth_passwd_changereq);
472 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
475 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
477 Authctxt *authctxt = ctxt;
478 char *info, *lang, *password = NULL, *retype = NULL;
481 debug2("input_userauth_passwd_changereq");
483 if (authctxt == NULL)
484 fatal("input_userauth_passwd_changereq: "
485 "no authentication context");
487 info = packet_get_string(NULL);
488 lang = packet_get_string(NULL);
489 if (strlen(info) > 0)
493 packet_start(SSH2_MSG_USERAUTH_REQUEST);
494 packet_put_cstring(authctxt->server_user);
495 packet_put_cstring(authctxt->service);
496 packet_put_cstring(authctxt->method->name);
497 packet_put_char(1); /* additional info */
498 snprintf(prompt, sizeof(prompt),
499 "Enter %.30s@%.128s's old password: ",
500 authctxt->server_user, authctxt->host);
501 password = read_passphrase(prompt, 0);
502 packet_put_cstring(password);
503 memset(password, 0, strlen(password));
506 while (password == NULL) {
507 snprintf(prompt, sizeof(prompt),
508 "Enter %.30s@%.128s's new password: ",
509 authctxt->server_user, authctxt->host);
510 password = read_passphrase(prompt, RP_ALLOW_EOF);
511 if (password == NULL) {
515 snprintf(prompt, sizeof(prompt),
516 "Retype %.30s@%.128s's new password: ",
517 authctxt->server_user, authctxt->host);
518 retype = read_passphrase(prompt, 0);
519 if (strcmp(password, retype) != 0) {
520 memset(password, 0, strlen(password));
522 log("Mismatch; try again, EOF to quit.");
525 memset(retype, 0, strlen(retype));
528 packet_put_cstring(password);
529 memset(password, 0, strlen(password));
531 packet_add_padding(64);
534 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
535 &input_userauth_passwd_changereq);
539 clear_auth_state(Authctxt *authctxt)
541 /* XXX clear authentication state */
542 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL);
544 if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) {
545 debug3("clear_auth_state: key_free %p", authctxt->last_key);
546 key_free(authctxt->last_key);
548 authctxt->last_key = NULL;
549 authctxt->last_key_hint = -2;
550 authctxt->last_key_sign = NULL;
554 sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
557 u_char *blob, *signature;
563 debug3("sign_and_send_pubkey");
565 if (key_to_blob(k, &blob, &bloblen) == 0) {
566 /* we cannot handle this key */
567 debug3("sign_and_send_pubkey: cannot handle key");
570 /* data to be signed */
572 if (datafellows & SSH_OLD_SESSIONID) {
573 buffer_append(&b, session_id2, session_id2_len);
574 skip = session_id2_len;
576 buffer_put_string(&b, session_id2, session_id2_len);
577 skip = buffer_len(&b);
579 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
580 buffer_put_cstring(&b, authctxt->server_user);
581 buffer_put_cstring(&b,
582 datafellows & SSH_BUG_PKSERVICE ?
585 if (datafellows & SSH_BUG_PKAUTH) {
586 buffer_put_char(&b, have_sig);
588 buffer_put_cstring(&b, authctxt->method->name);
589 buffer_put_char(&b, have_sig);
590 buffer_put_cstring(&b, key_ssh_name(k));
592 buffer_put_string(&b, blob, bloblen);
594 /* generate signature */
595 ret = (*sign_callback)(authctxt, k, &signature, &slen,
596 buffer_ptr(&b), buffer_len(&b));
605 if (datafellows & SSH_BUG_PKSERVICE) {
607 buffer_append(&b, session_id2, session_id2_len);
608 skip = session_id2_len;
609 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
610 buffer_put_cstring(&b, authctxt->server_user);
611 buffer_put_cstring(&b, authctxt->service);
612 buffer_put_cstring(&b, authctxt->method->name);
613 buffer_put_char(&b, have_sig);
614 if (!(datafellows & SSH_BUG_PKAUTH))
615 buffer_put_cstring(&b, key_ssh_name(k));
616 buffer_put_string(&b, blob, bloblen);
620 /* append signature */
621 buffer_put_string(&b, signature, slen);
624 /* skip session id and packet type */
625 if (buffer_len(&b) < skip + 1)
626 fatal("userauth_pubkey: internal error");
627 buffer_consume(&b, skip + 1);
629 /* put remaining data from buffer into packet */
630 packet_start(SSH2_MSG_USERAUTH_REQUEST);
631 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
639 send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback,
643 u_int bloblen, have_sig = 0;
645 debug3("send_pubkey_test");
647 if (key_to_blob(k, &blob, &bloblen) == 0) {
648 /* we cannot handle this key */
649 debug3("send_pubkey_test: cannot handle key");
652 /* register callback for USERAUTH_PK_OK message */
653 authctxt->last_key_sign = sign_callback;
654 authctxt->last_key_hint = hint;
655 authctxt->last_key = k;
656 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
658 packet_start(SSH2_MSG_USERAUTH_REQUEST);
659 packet_put_cstring(authctxt->server_user);
660 packet_put_cstring(authctxt->service);
661 packet_put_cstring(authctxt->method->name);
662 packet_put_char(have_sig);
663 if (!(datafellows & SSH_BUG_PKAUTH))
664 packet_put_cstring(key_ssh_name(k));
665 packet_put_string(blob, bloblen);
672 load_identity_file(char *filename)
675 char prompt[300], *passphrase;
679 if (stat(filename, &st) < 0) {
680 debug3("no such identity: %s", filename);
683 private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
684 if (private == NULL) {
685 if (options.batch_mode)
687 snprintf(prompt, sizeof prompt,
688 "Enter passphrase for key '%.100s': ", filename);
689 for (i = 0; i < options.number_of_password_prompts; i++) {
690 passphrase = read_passphrase(prompt, 0);
691 if (strcmp(passphrase, "") != 0) {
692 private = key_load_private_type(KEY_UNSPEC, filename,
696 debug2("no passphrase given, try next key");
699 memset(passphrase, 0, strlen(passphrase));
701 if (private != NULL || quit)
703 debug2("bad passphrase given, try again...");
710 identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
711 u_char *data, u_int datalen)
716 idx = authctxt->last_key_hint;
720 /* private key is stored in external hardware */
721 if (options.identity_keys[idx]->flags & KEY_FLAG_EXT)
722 return key_sign(options.identity_keys[idx], sigp, lenp, data, datalen);
724 private = load_identity_file(options.identity_files[idx]);
727 ret = key_sign(private, sigp, lenp, data, datalen);
733 agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
734 u_char *data, u_int datalen)
736 return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen);
740 key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
741 u_char *data, u_int datalen)
743 return key_sign(key, sigp, lenp, data, datalen);
747 userauth_pubkey_agent(Authctxt *authctxt)
749 static int called = 0;
755 if (ssh_get_num_identities(authctxt->agent, 2) == 0)
756 debug2("userauth_pubkey_agent: no keys at all");
759 k = ssh_get_next_identity(authctxt->agent, &comment, 2);
761 debug2("userauth_pubkey_agent: no more keys");
763 debug("userauth_pubkey_agent: testing agent key %s", comment);
765 ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1);
770 debug2("userauth_pubkey_agent: no message sent");
775 userauth_pubkey(Authctxt *authctxt)
782 if (authctxt->agent != NULL) {
784 sent = userauth_pubkey_agent(authctxt);
785 } while (!sent && authctxt->agent->howmany > 0);
787 while (!sent && idx < options.num_identity_files) {
788 key = options.identity_keys[idx];
789 filename = options.identity_files[idx];
791 debug("try privkey: %s", filename);
792 key = load_identity_file(filename);
794 sent = sign_and_send_pubkey(authctxt, key,
798 } else if (key->type != KEY_RSA1) {
799 debug("try pubkey: %s", filename);
800 sent = send_pubkey_test(authctxt, key,
801 identity_sign_cb, idx);
809 * Send userauth request message specifying keyboard-interactive method.
812 userauth_kbdint(Authctxt *authctxt)
814 static int attempt = 0;
816 if (attempt++ >= options.number_of_password_prompts)
818 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
819 if (attempt > 1 && !authctxt->info_req_seen) {
820 debug3("userauth_kbdint: disable: no info_req_seen");
821 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
825 debug2("userauth_kbdint");
826 packet_start(SSH2_MSG_USERAUTH_REQUEST);
827 packet_put_cstring(authctxt->server_user);
828 packet_put_cstring(authctxt->service);
829 packet_put_cstring(authctxt->method->name);
830 packet_put_cstring(""); /* lang */
831 packet_put_cstring(options.kbd_interactive_devices ?
832 options.kbd_interactive_devices : "");
835 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
840 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
843 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
845 Authctxt *authctxt = ctxt;
846 char *name, *inst, *lang, *prompt, *response;
847 u_int num_prompts, i;
850 debug2("input_userauth_info_req");
852 if (authctxt == NULL)
853 fatal("input_userauth_info_req: no authentication context");
855 authctxt->info_req_seen = 1;
857 name = packet_get_string(NULL);
858 inst = packet_get_string(NULL);
859 lang = packet_get_string(NULL);
860 if (strlen(name) > 0)
862 if (strlen(inst) > 0)
868 num_prompts = packet_get_int();
870 * Begin to build info response packet based on prompts requested.
871 * We commit to providing the correct number of responses, so if
872 * further on we run into a problem that prevents this, we have to
873 * be sure and clean this up and send a correct error response.
875 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
876 packet_put_int(num_prompts);
878 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
879 for (i = 0; i < num_prompts; i++) {
880 prompt = packet_get_string(NULL);
881 echo = packet_get_char();
883 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
885 packet_put_cstring(response);
886 memset(response, 0, strlen(response));
890 packet_check_eom(); /* done with parsing incoming message. */
892 packet_add_padding(64);
897 * this will be move to an external program (ssh-keysign) ASAP. ssh-keysign
898 * will be setuid-root and the sbit can be removed from /usr/bin/ssh.
901 userauth_hostbased(Authctxt *authctxt)
905 u_char *signature, *blob;
906 char *chost, *pkalg, *p;
909 int ok, i, len, found = 0;
911 /* check for a useful key */
912 for (i = 0; i < authctxt->nkeys; i++) {
913 private = authctxt->keys[i];
914 if (private && private->type != KEY_RSA1) {
916 /* we take and free the key */
917 authctxt->keys[i] = NULL;
922 debug("userauth_hostbased: no more client hostkeys");
925 if (key_to_blob(private, &blob, &blen) == 0) {
929 /* figure out a name for the client host */
930 p = get_local_name(packet_get_connection_in());
932 error("userauth_hostbased: cannot get local ipaddr/name");
937 chost = xmalloc(len);
938 strlcpy(chost, p, len);
939 strlcat(chost, ".", len);
940 debug2("userauth_hostbased: chost %s", chost);
942 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
944 pkalg = xstrdup(key_ssh_name(private));
947 buffer_put_string(&b, session_id2, session_id2_len);
948 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
949 buffer_put_cstring(&b, authctxt->server_user);
950 buffer_put_cstring(&b, service);
951 buffer_put_cstring(&b, authctxt->method->name);
952 buffer_put_cstring(&b, pkalg);
953 buffer_put_string(&b, blob, blen);
954 buffer_put_cstring(&b, chost);
955 buffer_put_cstring(&b, authctxt->local_user);
959 ok = key_sign(private, &signature, &slen, buffer_ptr(&b), buffer_len(&b));
963 error("key_sign failed");
968 packet_start(SSH2_MSG_USERAUTH_REQUEST);
969 packet_put_cstring(authctxt->server_user);
970 packet_put_cstring(authctxt->service);
971 packet_put_cstring(authctxt->method->name);
972 packet_put_cstring(pkalg);
973 packet_put_string(blob, blen);
974 packet_put_cstring(chost);
975 packet_put_cstring(authctxt->local_user);
976 packet_put_string(signature, slen);
977 memset(signature, 's', slen);
986 /* find auth method */
989 * given auth method name, if configurable options permit this method fill
990 * in auth_ident field and return true, otherwise return false.
993 authmethod_is_enabled(Authmethod *method)
997 /* return false if options indicate this method is disabled */
998 if (method->enabled == NULL || *method->enabled == 0)
1000 /* return false if batch mode is enabled but method needs interactive mode */
1001 if (method->batch_flag != NULL && *method->batch_flag != 0)
1007 authmethod_lookup(const char *name)
1009 Authmethod *method = NULL;
1011 for (method = authmethods; method->name != NULL; method++)
1012 if (strcmp(name, method->name) == 0)
1014 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1018 /* XXX internal state */
1019 static Authmethod *current = NULL;
1020 static char *supported = NULL;
1021 static char *preferred = NULL;
1023 * Given the authentication method list sent by the server, return the
1024 * next method we should try. If the server initially sends a nil list,
1025 * use a built-in default list.
1028 authmethod_get(char *authlist)
1034 /* Use a suitable default if we're passed a nil list. */
1035 if (authlist == NULL || strlen(authlist) == 0)
1036 authlist = options.preferred_authentications;
1038 if (supported == NULL || strcmp(authlist, supported) != 0) {
1039 debug3("start over, passed a different list %s", authlist);
1040 if (supported != NULL)
1042 supported = xstrdup(authlist);
1043 preferred = options.preferred_authentications;
1044 debug3("preferred %s", preferred);
1046 } else if (current != NULL && authmethod_is_enabled(current))
1050 if ((name = match_list(preferred, supported, &next)) == NULL) {
1051 debug("no more auth methods to try");
1056 debug3("authmethod_lookup %s", name);
1057 debug3("remaining preferred: %s", preferred);
1058 if ((current = authmethod_lookup(name)) != NULL &&
1059 authmethod_is_enabled(current)) {
1060 debug3("authmethod_is_enabled %s", name);
1061 debug("next auth method to try is %s", name);
1068 authmethods_get(void)
1070 Authmethod *method = NULL;
1075 for (method = authmethods; method->name != NULL; method++) {
1076 if (authmethod_is_enabled(method)) {
1077 if (buffer_len(&b) > 0)
1078 buffer_append(&b, ",", 1);
1079 buffer_append(&b, method->name, strlen(method->name));
1082 buffer_append(&b, "\0", 1);
1083 list = xstrdup(buffer_ptr(&b));