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 1.105 2002/06/23 03:30:17 deraadt Exp $");
37 #include "myproposal.h"
38 #include "sshconnect.h"
49 #include "pathnames.h"
56 extern char *client_version_string;
57 extern char *server_version_string;
58 extern Options options;
64 u_char *session_id2 = NULL;
65 int session_id2_len = 0;
68 struct sockaddr *xxx_hostaddr;
73 verify_host_key_callback(Key *hostkey)
75 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
76 fatal("Host key verification failed.");
81 ssh_kex2(char *host, struct sockaddr *hostaddr)
90 xxx_hostaddr = hostaddr;
93 /* Add the GSSAPI mechanisms currently supported on this client to
94 * the key exchange algorithm proposal */
95 orig = myproposal[PROPOSAL_KEX_ALGS];
96 gss = ssh_gssapi_mechanisms(0,host);
98 len = strlen(orig)+strlen(gss)+2;
99 myproposal[PROPOSAL_KEX_ALGS]=xmalloc(len);
100 snprintf(myproposal[PROPOSAL_KEX_ALGS],len,"%s,%s",gss,orig);
104 if (options.ciphers == (char *)-1) {
105 log("No valid ciphers for protocol version 2 given, using defaults.");
106 options.ciphers = NULL;
108 if (options.ciphers != NULL) {
109 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
110 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
112 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
113 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
114 myproposal[PROPOSAL_ENC_ALGS_STOC] =
115 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
116 if (options.compression) {
117 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
118 myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib";
120 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
121 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
123 if (options.macs != NULL) {
124 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
125 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
127 if (options.hostkeyalgorithms != NULL)
128 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
129 options.hostkeyalgorithms;
132 /* If we've got GSSAPI algorithms, then we also support the
133 * 'null' hostkey, as a last resort */
135 orig=myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS];
136 len = strlen(orig)+sizeof(",null");
137 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]=xmalloc(len);
138 snprintf(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS],len,"%s,null",orig);
142 /* start key exchange */
143 kex = kex_setup(myproposal);
144 kex->client_version_string=client_version_string;
145 kex->server_version_string=server_version_string;
146 kex->verify_host_key=&verify_host_key_callback;
150 kex->options.gss_deleg_creds=options.gss_deleg_creds;
155 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
157 session_id2 = kex->session_id;
158 session_id2_len = kex->session_id_len;
161 /* send 1st encrypted/maced/compressed message */
162 packet_start(SSH2_MSG_IGNORE);
163 packet_put_cstring("markus");
167 debug("done: ssh_kex2.");
174 typedef struct Authctxt Authctxt;
175 typedef struct Authmethod Authmethod;
177 typedef int sign_cb_fn(
178 Authctxt *authctxt, Key *key,
179 u_char **sigp, u_int *lenp, u_char *data, u_int datalen);
182 const char *server_user;
183 const char *local_user;
191 sign_cb_fn *last_key_sign;
193 AuthenticationConnection *agent;
195 Sensitive *sensitive;
196 /* kbd-interactive */
202 char *name; /* string to compare against server's list */
203 int (*userauth)(Authctxt *authctxt);
204 int *enabled; /* flag in option struct that enables method */
205 int *batch_flag; /* flag in option struct that disables method */
208 void input_userauth_success(int, u_int32_t, void *);
209 void input_userauth_failure(int, u_int32_t, void *);
210 void input_userauth_banner(int, u_int32_t, void *);
211 void input_userauth_error(int, u_int32_t, void *);
212 void input_userauth_info_req(int, u_int32_t, void *);
213 void input_userauth_pk_ok(int, u_int32_t, void *);
214 void input_userauth_passwd_changereq(int, u_int32_t, void *);
216 int userauth_none(Authctxt *);
217 int userauth_pubkey(Authctxt *);
218 int userauth_passwd(Authctxt *);
219 int userauth_kbdint(Authctxt *);
220 int userauth_hostbased(Authctxt *);
223 int userauth_external(Authctxt *authctxt);
224 int userauth_gssapi(Authctxt *authctxt);
225 void input_gssapi_response(int type, u_int32_t plen, void *ctxt);
226 void input_gssapi_token(int type, u_int32_t plen, void *ctxt);
227 void input_gssapi_hash(int type, u_int32_t plen, void *ctxt);
230 void userauth(Authctxt *, char *);
232 static int sign_and_send_pubkey(Authctxt *, Key *, sign_cb_fn *);
233 static void clear_auth_state(Authctxt *);
235 static Authmethod *authmethod_get(char *authlist);
236 static Authmethod *authmethod_lookup(const char *name);
237 static char *authmethods_get(void);
239 Authmethod authmethods[] = {
243 &options.gss_authentication,
247 &options.gss_authentication,
252 &options.hostbased_authentication,
256 &options.pubkey_authentication,
258 {"keyboard-interactive",
260 &options.kbd_interactive_authentication,
261 &options.batch_mode},
264 &options.password_authentication,
265 &options.batch_mode},
270 {NULL, NULL, NULL, NULL}
274 ssh_userauth2(const char *local_user, const char *server_user, char *host,
275 Sensitive *sensitive)
280 if (options.challenge_response_authentication)
281 options.kbd_interactive_authentication = 1;
283 debug("send SSH2_MSG_SERVICE_REQUEST");
284 packet_start(SSH2_MSG_SERVICE_REQUEST);
285 packet_put_cstring("ssh-userauth");
288 type = packet_read();
289 if (type != SSH2_MSG_SERVICE_ACCEPT) {
290 fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type);
292 if (packet_remaining() > 0) {
293 char *reply = packet_get_string(NULL);
294 debug("service_accept: %s", reply);
297 debug("buggy server: service_accept w/o service");
300 debug("got SSH2_MSG_SERVICE_ACCEPT");
302 if (options.preferred_authentications == NULL)
303 options.preferred_authentications = authmethods_get();
305 /* setup authentication context */
306 memset(&authctxt, 0, sizeof(authctxt));
307 authctxt.agent = ssh_get_authentication_connection();
308 authctxt.server_user = server_user;
309 authctxt.local_user = local_user;
310 authctxt.host = host;
311 authctxt.service = "ssh-connection"; /* service name */
312 authctxt.success = 0;
313 authctxt.method = authmethod_lookup("none");
314 authctxt.authlist = NULL;
315 authctxt.methoddata = NULL;
316 authctxt.sensitive = sensitive;
317 authctxt.info_req_seen = 0;
318 if (authctxt.method == NULL)
319 fatal("ssh_userauth2: internal error: cannot send userauth none request");
321 /* initial userauth request */
322 userauth_none(&authctxt);
324 dispatch_init(&input_userauth_error);
325 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
326 dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
327 dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
328 dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
330 if (authctxt.agent != NULL)
331 ssh_close_authentication_connection(authctxt.agent);
333 debug("ssh-userauth2 successful: method %s", authctxt.method->name);
336 userauth(Authctxt *authctxt, char *authlist)
338 if (authctxt->methoddata!=NULL) {
339 xfree(authctxt->methoddata);
340 authctxt->methoddata=NULL;
343 if (authlist == NULL) {
344 authlist = authctxt->authlist;
346 if (authctxt->authlist)
347 xfree(authctxt->authlist);
348 authctxt->authlist = authlist;
351 Authmethod *method = authmethod_get(authlist);
353 fatal("Permission denied (%s).", authlist);
354 authctxt->method = method;
355 if (method->userauth(authctxt) != 0) {
356 debug2("we sent a %s packet, wait for reply", method->name);
359 debug2("we did not send a packet, disable method");
360 method->enabled = NULL;
366 input_userauth_error(int type, u_int32_t seq, void *ctxt)
368 fatal("input_userauth_error: bad message during authentication: "
373 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
376 debug3("input_userauth_banner");
377 msg = packet_get_string(NULL);
378 lang = packet_get_string(NULL);
379 fprintf(stderr, "%s", msg);
385 input_userauth_success(int type, u_int32_t seq, void *ctxt)
387 Authctxt *authctxt = ctxt;
388 if (authctxt == NULL)
389 fatal("input_userauth_success: no authentication context");
390 if (authctxt->authlist)
391 xfree(authctxt->authlist);
392 if (authctxt->methoddata)
393 xfree(authctxt->methoddata);
394 clear_auth_state(authctxt);
395 authctxt->success = 1; /* break out */
399 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
401 Authctxt *authctxt = ctxt;
402 char *authlist = NULL;
405 if (authctxt == NULL)
406 fatal("input_userauth_failure: no authentication context");
408 authlist = packet_get_string(NULL);
409 partial = packet_get_char();
413 log("Authenticated with partial success.");
414 debug("authentications that can continue: %s", authlist);
416 clear_auth_state(authctxt);
417 userauth(authctxt, authlist);
420 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
422 Authctxt *authctxt = ctxt;
425 int pktype, sent = 0;
430 if (authctxt == NULL)
431 fatal("input_userauth_pk_ok: no authentication context");
432 if (datafellows & SSH_BUG_PKOK) {
433 /* this is similar to SSH_BUG_PKAUTH */
434 debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
435 pkblob = packet_get_string(&blen);
437 buffer_append(&b, pkblob, blen);
438 pkalg = buffer_get_string(&b, &alen);
441 pkalg = packet_get_string(&alen);
442 pkblob = packet_get_string(&blen);
446 debug("input_userauth_pk_ok: pkalg %s blen %u lastkey %p hint %d",
447 pkalg, blen, authctxt->last_key, authctxt->last_key_hint);
450 if (authctxt->last_key == NULL ||
451 authctxt->last_key_sign == NULL) {
452 debug("no last key or no sign cb");
455 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
456 debug("unknown pkalg %s", pkalg);
459 if ((key = key_from_blob(pkblob, blen)) == NULL) {
460 debug("no key from blob. pkalg %s", pkalg);
463 if (key->type != pktype) {
464 error("input_userauth_pk_ok: type mismatch "
465 "for decoded key (received %d, expected %d)",
469 fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
470 debug2("input_userauth_pk_ok: fp %s", fp);
472 if (!key_equal(key, authctxt->last_key)) {
473 debug("key != last_key");
476 sent = sign_and_send_pubkey(authctxt, key,
477 authctxt->last_key_sign);
486 clear_auth_state(authctxt);
487 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL);
489 /* try another method if we did not send a packet*/
491 userauth(authctxt, NULL);
497 userauth_gssapi(Authctxt *authctxt)
503 /* For now, we only make one attempt at this. We could try offering
504 * the server different GSSAPI OIDs until we get bored, I suppose.
506 if (tries++>0) return 0;
508 if (datafellows & SSH_OLD_GSSAPI) return 0;
510 /* Initialise as much of our context as we can, so failures can be
511 * trapped before sending any packets.
513 ssh_gssapi_build_ctx(&gssctxt);
515 if (ssh_gssapi_import_name(gssctxt,authctxt->host)) {
519 authctxt->methoddata=(void *)gssctxt;
521 packet_start(SSH2_MSG_USERAUTH_REQUEST);
522 if(options.implicit && !(datafellows & SSH_BUG_GSS_EMPTYUSER)) {
523 packet_put_cstring("");
525 packet_put_cstring(authctxt->server_user);
527 packet_put_cstring(authctxt->service);
528 packet_put_cstring(authctxt->method->name);
530 /* FIXME: This assumes that our current GSSAPI implementation
531 * supports all of the mechanisms listed in supported_mechs.
532 * This may not be the case - we should use something along
533 * the lines of the code in gss_genr to remove the ones that
534 * aren't supported */
535 packet_put_int(GSS_LAST_ENTRY);
536 for (i=0;i<GSS_LAST_ENTRY;i++) {
537 packet_put_string(supported_mechs[i].oid.elements,
538 supported_mechs[i].oid.length);
543 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,&input_gssapi_response);
544 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,&input_gssapi_token);
550 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
552 Authctxt *authctxt = ctxt;
557 gss_buffer_desc send_tok;
559 if (authctxt == NULL)
560 fatal("input_gssapi_response: no authentication context");
561 gssctxt = authctxt->methoddata;
564 oidv=packet_get_string(&oidlen);
565 ssh_gssapi_set_oid_data(gssctxt,oidv,oidlen);
569 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
570 GSS_C_NO_BUFFER, &send_tok,
572 if (GSS_ERROR(status)) {
573 /* Start again with next method on list */
574 debug("Trying to start again");
575 userauth(authctxt,NULL);
579 /* We must have data to send */
580 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
581 packet_put_string(send_tok.value,send_tok.length);
584 gss_release_buffer(&ms, &send_tok);
588 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
590 Authctxt *authctxt = ctxt;
592 gss_buffer_desc send_tok,recv_tok;
595 if (authctxt == NULL)
596 fatal("input_gssapi_response: no authentication context");
597 gssctxt = authctxt->methoddata;
599 recv_tok.value=packet_get_string(&recv_tok.length);
601 status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
602 &recv_tok, &send_tok, NULL);
606 if (GSS_ERROR(status)) {
607 /* Start again with the next method in the list */
608 userauth(authctxt,NULL);
612 if (send_tok.length>0) {
613 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
614 packet_put_string(send_tok.value,send_tok.length);
619 if (status == GSS_S_COMPLETE) {
620 /* If that succeeded, send a exchange complete message */
621 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
628 userauth_external(Authctxt *authctxt)
630 static int attempt =0;
635 debug2("userauth_external");
636 packet_start(SSH2_MSG_USERAUTH_REQUEST);
637 if(options.implicit && !(datafellows & SSH_BUG_GSS_EMPTYUSER)) {
638 packet_put_cstring("");
640 packet_put_cstring(authctxt->server_user);
642 packet_put_cstring(authctxt->service);
643 packet_put_cstring(authctxt->method->name);
651 userauth_none(Authctxt *authctxt)
653 /* initial userauth request */
654 packet_start(SSH2_MSG_USERAUTH_REQUEST);
655 packet_put_cstring(authctxt->server_user);
656 packet_put_cstring(authctxt->service);
657 packet_put_cstring(authctxt->method->name);
664 userauth_passwd(Authctxt *authctxt)
666 static int attempt = 0;
670 if (attempt++ >= options.number_of_password_prompts)
674 error("Permission denied, please try again.");
676 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
677 authctxt->server_user, authctxt->host);
678 password = read_passphrase(prompt, 0);
679 packet_start(SSH2_MSG_USERAUTH_REQUEST);
680 packet_put_cstring(authctxt->server_user);
681 packet_put_cstring(authctxt->service);
682 packet_put_cstring(authctxt->method->name);
684 packet_put_cstring(password);
685 memset(password, 0, strlen(password));
687 packet_add_padding(64);
690 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
691 &input_userauth_passwd_changereq);
696 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
699 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
701 Authctxt *authctxt = ctxt;
702 char *info, *lang, *password = NULL, *retype = NULL;
705 debug2("input_userauth_passwd_changereq");
707 if (authctxt == NULL)
708 fatal("input_userauth_passwd_changereq: "
709 "no authentication context");
711 info = packet_get_string(NULL);
712 lang = packet_get_string(NULL);
713 if (strlen(info) > 0)
717 packet_start(SSH2_MSG_USERAUTH_REQUEST);
718 packet_put_cstring(authctxt->server_user);
719 packet_put_cstring(authctxt->service);
720 packet_put_cstring(authctxt->method->name);
721 packet_put_char(1); /* additional info */
722 snprintf(prompt, sizeof(prompt),
723 "Enter %.30s@%.128s's old password: ",
724 authctxt->server_user, authctxt->host);
725 password = read_passphrase(prompt, 0);
726 packet_put_cstring(password);
727 memset(password, 0, strlen(password));
730 while (password == NULL) {
731 snprintf(prompt, sizeof(prompt),
732 "Enter %.30s@%.128s's new password: ",
733 authctxt->server_user, authctxt->host);
734 password = read_passphrase(prompt, RP_ALLOW_EOF);
735 if (password == NULL) {
739 snprintf(prompt, sizeof(prompt),
740 "Retype %.30s@%.128s's new password: ",
741 authctxt->server_user, authctxt->host);
742 retype = read_passphrase(prompt, 0);
743 if (strcmp(password, retype) != 0) {
744 memset(password, 0, strlen(password));
746 log("Mismatch; try again, EOF to quit.");
749 memset(retype, 0, strlen(retype));
752 packet_put_cstring(password);
753 memset(password, 0, strlen(password));
755 packet_add_padding(64);
758 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
759 &input_userauth_passwd_changereq);
763 clear_auth_state(Authctxt *authctxt)
765 /* XXX clear authentication state */
766 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL);
768 if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) {
769 debug3("clear_auth_state: key_free %p", authctxt->last_key);
770 key_free(authctxt->last_key);
772 authctxt->last_key = NULL;
773 authctxt->last_key_hint = -2;
774 authctxt->last_key_sign = NULL;
778 sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
781 u_char *blob, *signature;
787 debug3("sign_and_send_pubkey");
789 if (key_to_blob(k, &blob, &bloblen) == 0) {
790 /* we cannot handle this key */
791 debug3("sign_and_send_pubkey: cannot handle key");
794 /* data to be signed */
796 if (datafellows & SSH_OLD_SESSIONID) {
797 buffer_append(&b, session_id2, session_id2_len);
798 skip = session_id2_len;
800 buffer_put_string(&b, session_id2, session_id2_len);
801 skip = buffer_len(&b);
803 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
804 buffer_put_cstring(&b, authctxt->server_user);
805 buffer_put_cstring(&b,
806 datafellows & SSH_BUG_PKSERVICE ?
809 if (datafellows & SSH_BUG_PKAUTH) {
810 buffer_put_char(&b, have_sig);
812 buffer_put_cstring(&b, authctxt->method->name);
813 buffer_put_char(&b, have_sig);
814 buffer_put_cstring(&b, key_ssh_name(k));
816 buffer_put_string(&b, blob, bloblen);
818 /* generate signature */
819 ret = (*sign_callback)(authctxt, k, &signature, &slen,
820 buffer_ptr(&b), buffer_len(&b));
829 if (datafellows & SSH_BUG_PKSERVICE) {
831 buffer_append(&b, session_id2, session_id2_len);
832 skip = session_id2_len;
833 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
834 buffer_put_cstring(&b, authctxt->server_user);
835 buffer_put_cstring(&b, authctxt->service);
836 buffer_put_cstring(&b, authctxt->method->name);
837 buffer_put_char(&b, have_sig);
838 if (!(datafellows & SSH_BUG_PKAUTH))
839 buffer_put_cstring(&b, key_ssh_name(k));
840 buffer_put_string(&b, blob, bloblen);
844 /* append signature */
845 buffer_put_string(&b, signature, slen);
848 /* skip session id and packet type */
849 if (buffer_len(&b) < skip + 1)
850 fatal("userauth_pubkey: internal error");
851 buffer_consume(&b, skip + 1);
853 /* put remaining data from buffer into packet */
854 packet_start(SSH2_MSG_USERAUTH_REQUEST);
855 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
863 send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback,
867 u_int bloblen, have_sig = 0;
869 debug3("send_pubkey_test");
871 if (key_to_blob(k, &blob, &bloblen) == 0) {
872 /* we cannot handle this key */
873 debug3("send_pubkey_test: cannot handle key");
876 /* register callback for USERAUTH_PK_OK message */
877 authctxt->last_key_sign = sign_callback;
878 authctxt->last_key_hint = hint;
879 authctxt->last_key = k;
880 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
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);
886 packet_put_char(have_sig);
887 if (!(datafellows & SSH_BUG_PKAUTH))
888 packet_put_cstring(key_ssh_name(k));
889 packet_put_string(blob, bloblen);
896 load_identity_file(char *filename)
899 char prompt[300], *passphrase;
903 if (stat(filename, &st) < 0) {
904 debug3("no such identity: %s", filename);
907 private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
908 if (private == NULL) {
909 if (options.batch_mode)
911 snprintf(prompt, sizeof prompt,
912 "Enter passphrase for key '%.100s': ", filename);
913 for (i = 0; i < options.number_of_password_prompts; i++) {
914 passphrase = read_passphrase(prompt, 0);
915 if (strcmp(passphrase, "") != 0) {
916 private = key_load_private_type(KEY_UNSPEC, filename,
920 debug2("no passphrase given, try next key");
923 memset(passphrase, 0, strlen(passphrase));
925 if (private != NULL || quit)
927 debug2("bad passphrase given, try again...");
934 identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
935 u_char *data, u_int datalen)
940 idx = authctxt->last_key_hint;
944 /* private key is stored in external hardware */
945 if (options.identity_keys[idx]->flags & KEY_FLAG_EXT)
946 return key_sign(options.identity_keys[idx], sigp, lenp, data, datalen);
948 private = load_identity_file(options.identity_files[idx]);
951 ret = key_sign(private, sigp, lenp, data, datalen);
957 agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
958 u_char *data, u_int datalen)
960 return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen);
964 key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
965 u_char *data, u_int datalen)
967 return key_sign(key, sigp, lenp, data, datalen);
971 userauth_pubkey_agent(Authctxt *authctxt)
973 static int called = 0;
979 if (ssh_get_num_identities(authctxt->agent, 2) == 0)
980 debug2("userauth_pubkey_agent: no keys at all");
983 k = ssh_get_next_identity(authctxt->agent, &comment, 2);
985 debug2("userauth_pubkey_agent: no more keys");
987 debug("userauth_pubkey_agent: testing agent key %s", comment);
989 ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1);
994 debug2("userauth_pubkey_agent: no message sent");
999 userauth_pubkey(Authctxt *authctxt)
1006 if (authctxt->agent != NULL) {
1008 sent = userauth_pubkey_agent(authctxt);
1009 } while (!sent && authctxt->agent->howmany > 0);
1011 while (!sent && idx < options.num_identity_files) {
1012 key = options.identity_keys[idx];
1013 filename = options.identity_files[idx];
1015 debug("try privkey: %s", filename);
1016 key = load_identity_file(filename);
1018 sent = sign_and_send_pubkey(authctxt, key,
1022 } else if (key->type != KEY_RSA1) {
1023 debug("try pubkey: %s", filename);
1024 sent = send_pubkey_test(authctxt, key,
1025 identity_sign_cb, idx);
1033 * Send userauth request message specifying keyboard-interactive method.
1036 userauth_kbdint(Authctxt *authctxt)
1038 static int attempt = 0;
1040 if (attempt++ >= options.number_of_password_prompts)
1042 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1043 if (attempt > 1 && !authctxt->info_req_seen) {
1044 debug3("userauth_kbdint: disable: no info_req_seen");
1045 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1049 debug2("userauth_kbdint");
1050 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1051 packet_put_cstring(authctxt->server_user);
1052 packet_put_cstring(authctxt->service);
1053 packet_put_cstring(authctxt->method->name);
1054 packet_put_cstring(""); /* lang */
1055 packet_put_cstring(options.kbd_interactive_devices ?
1056 options.kbd_interactive_devices : "");
1059 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1064 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1067 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1069 Authctxt *authctxt = ctxt;
1070 char *name, *inst, *lang, *prompt, *response;
1071 u_int num_prompts, i;
1074 debug2("input_userauth_info_req");
1076 if (authctxt == NULL)
1077 fatal("input_userauth_info_req: no authentication context");
1079 authctxt->info_req_seen = 1;
1081 name = packet_get_string(NULL);
1082 inst = packet_get_string(NULL);
1083 lang = packet_get_string(NULL);
1084 if (strlen(name) > 0)
1086 if (strlen(inst) > 0)
1092 num_prompts = packet_get_int();
1094 * Begin to build info response packet based on prompts requested.
1095 * We commit to providing the correct number of responses, so if
1096 * further on we run into a problem that prevents this, we have to
1097 * be sure and clean this up and send a correct error response.
1099 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1100 packet_put_int(num_prompts);
1102 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1103 for (i = 0; i < num_prompts; i++) {
1104 prompt = packet_get_string(NULL);
1105 echo = packet_get_char();
1107 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1109 packet_put_cstring(response);
1110 memset(response, 0, strlen(response));
1114 packet_check_eom(); /* done with parsing incoming message. */
1116 packet_add_padding(64);
1121 ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1122 u_char *data, u_int datalen)
1127 int to[2], from[2], status, version = 2;
1129 debug("ssh_keysign called");
1131 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1132 error("ssh_keysign: no installed: %s", strerror(errno));
1135 if (fflush(stdout) != 0)
1136 error("ssh_keysign: fflush: %s", strerror(errno));
1138 error("ssh_keysign: pipe: %s", strerror(errno));
1141 if (pipe(from) < 0) {
1142 error("ssh_keysign: pipe: %s", strerror(errno));
1145 if ((pid = fork()) < 0) {
1146 error("ssh_keysign: fork: %s", strerror(errno));
1153 if (dup2(from[1], STDOUT_FILENO) < 0)
1154 fatal("ssh_keysign: dup2: %s", strerror(errno));
1156 if (dup2(to[0], STDIN_FILENO) < 0)
1157 fatal("ssh_keysign: dup2: %s", strerror(errno));
1160 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1161 fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1168 buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1169 buffer_put_string(&b, data, datalen);
1170 msg_send(to[1], version, &b);
1172 if (msg_recv(from[0], &b) < 0) {
1173 error("ssh_keysign: no reply");
1180 while (waitpid(pid, &status, 0) < 0)
1184 if (buffer_get_char(&b) != version) {
1185 error("ssh_keysign: bad version");
1189 *sigp = buffer_get_string(&b, lenp);
1196 userauth_hostbased(Authctxt *authctxt)
1198 Key *private = NULL;
1199 Sensitive *sensitive = authctxt->sensitive;
1201 u_char *signature, *blob;
1202 char *chost, *pkalg, *p;
1203 const char *service;
1205 int ok, i, len, found = 0;
1207 /* check for a useful key */
1208 for (i = 0; i < sensitive->nkeys; i++) {
1209 private = sensitive->keys[i];
1210 if (private && private->type != KEY_RSA1) {
1212 /* we take and free the key */
1213 sensitive->keys[i] = NULL;
1218 debug("userauth_hostbased: no more client hostkeys");
1221 if (key_to_blob(private, &blob, &blen) == 0) {
1225 /* figure out a name for the client host */
1226 p = get_local_name(packet_get_connection_in());
1228 error("userauth_hostbased: cannot get local ipaddr/name");
1232 len = strlen(p) + 2;
1233 chost = xmalloc(len);
1234 strlcpy(chost, p, len);
1235 strlcat(chost, ".", len);
1236 debug2("userauth_hostbased: chost %s", chost);
1238 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1240 pkalg = xstrdup(key_ssh_name(private));
1242 /* construct data */
1243 buffer_put_string(&b, session_id2, session_id2_len);
1244 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1245 buffer_put_cstring(&b, authctxt->server_user);
1246 buffer_put_cstring(&b, service);
1247 buffer_put_cstring(&b, authctxt->method->name);
1248 buffer_put_cstring(&b, pkalg);
1249 buffer_put_string(&b, blob, blen);
1250 buffer_put_cstring(&b, chost);
1251 buffer_put_cstring(&b, authctxt->local_user);
1255 if (sensitive->external_keysign)
1256 ok = ssh_keysign(private, &signature, &slen,
1257 buffer_ptr(&b), buffer_len(&b));
1259 ok = key_sign(private, &signature, &slen,
1260 buffer_ptr(&b), buffer_len(&b));
1264 error("key_sign failed");
1269 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1270 packet_put_cstring(authctxt->server_user);
1271 packet_put_cstring(authctxt->service);
1272 packet_put_cstring(authctxt->method->name);
1273 packet_put_cstring(pkalg);
1274 packet_put_string(blob, blen);
1275 packet_put_cstring(chost);
1276 packet_put_cstring(authctxt->local_user);
1277 packet_put_string(signature, slen);
1278 memset(signature, 's', slen);
1287 /* find auth method */
1290 * given auth method name, if configurable options permit this method fill
1291 * in auth_ident field and return true, otherwise return false.
1294 authmethod_is_enabled(Authmethod *method)
1298 /* return false if options indicate this method is disabled */
1299 if (method->enabled == NULL || *method->enabled == 0)
1301 /* return false if batch mode is enabled but method needs interactive mode */
1302 if (method->batch_flag != NULL && *method->batch_flag != 0)
1308 authmethod_lookup(const char *name)
1310 Authmethod *method = NULL;
1312 for (method = authmethods; method->name != NULL; method++)
1313 if (strcmp(name, method->name) == 0)
1315 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1319 /* XXX internal state */
1320 static Authmethod *current = NULL;
1321 static char *supported = NULL;
1322 static char *preferred = NULL;
1325 * Given the authentication method list sent by the server, return the
1326 * next method we should try. If the server initially sends a nil list,
1327 * use a built-in default list.
1330 authmethod_get(char *authlist)
1336 /* Use a suitable default if we're passed a nil list. */
1337 if (authlist == NULL || strlen(authlist) == 0)
1338 authlist = options.preferred_authentications;
1340 if (supported == NULL || strcmp(authlist, supported) != 0) {
1341 debug3("start over, passed a different list %s", authlist);
1342 if (supported != NULL)
1344 supported = xstrdup(authlist);
1345 preferred = options.preferred_authentications;
1346 debug3("preferred %s", preferred);
1348 } else if (current != NULL && authmethod_is_enabled(current))
1352 if ((name = match_list(preferred, supported, &next)) == NULL) {
1353 debug("no more auth methods to try");
1358 debug3("authmethod_lookup %s", name);
1359 debug3("remaining preferred: %s", preferred);
1360 if ((current = authmethod_lookup(name)) != NULL &&
1361 authmethod_is_enabled(current)) {
1362 debug3("authmethod_is_enabled %s", name);
1363 debug("next auth method to try is %s", name);
1370 authmethods_get(void)
1372 Authmethod *method = NULL;
1377 for (method = authmethods; method->name != NULL; method++) {
1378 if (authmethod_is_enabled(method)) {
1379 if (buffer_len(&b) > 0)
1380 buffer_append(&b, ",", 1);
1381 buffer_append(&b, method->name, strlen(method->name));
1384 buffer_append(&b, "\0", 1);
1385 list = xstrdup(buffer_ptr(&b));