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);
523 if(options.implicit && !(datafellows & SSH_BUG_GSS_EMPTYUSER)) {
524 packet_put_cstring("");
527 packet_put_cstring(authctxt->server_user);
531 packet_put_cstring(authctxt->service);
532 packet_put_cstring(authctxt->method->name);
534 /* FIXME: This assumes that our current GSSAPI implementation
535 * supports all of the mechanisms listed in supported_mechs.
536 * This may not be the case - we should use something along
537 * the lines of the code in gss_genr to remove the ones that
538 * aren't supported */
539 packet_put_int(GSS_LAST_ENTRY);
540 for (i=0;i<GSS_LAST_ENTRY;i++) {
541 packet_put_string(supported_mechs[i].oid.elements,
542 supported_mechs[i].oid.length);
547 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,&input_gssapi_response);
548 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,&input_gssapi_token);
554 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
556 Authctxt *authctxt = ctxt;
561 gss_buffer_desc send_tok;
563 if (authctxt == NULL)
564 fatal("input_gssapi_response: no authentication context");
565 gssctxt = authctxt->methoddata;
568 oidv=packet_get_string(&oidlen);
569 ssh_gssapi_set_oid_data(gssctxt,oidv,oidlen);
573 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
574 GSS_C_NO_BUFFER, &send_tok,
576 if (GSS_ERROR(status)) {
577 /* Start again with next method on list */
578 debug("Trying to start again");
579 userauth(authctxt,NULL);
583 /* We must have data to send */
584 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
585 packet_put_string(send_tok.value,send_tok.length);
588 gss_release_buffer(&ms, &send_tok);
592 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
594 Authctxt *authctxt = ctxt;
596 gss_buffer_desc send_tok,recv_tok;
600 if (authctxt == NULL)
601 fatal("input_gssapi_response: no authentication context");
602 gssctxt = authctxt->methoddata;
604 recv_tok.value=packet_get_string(&slen);
605 recv_tok.length=slen; /* safe typecast */
607 status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
608 &recv_tok, &send_tok, NULL);
612 if (GSS_ERROR(status)) {
613 /* Start again with the next method in the list */
614 userauth(authctxt,NULL);
618 if (send_tok.length>0) {
619 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
620 packet_put_string(send_tok.value,send_tok.length);
625 if (status == GSS_S_COMPLETE) {
626 /* If that succeeded, send a exchange complete message */
627 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
634 userauth_external(Authctxt *authctxt)
636 static int attempt =0;
641 debug2("userauth_external");
642 packet_start(SSH2_MSG_USERAUTH_REQUEST);
644 if(options.implicit && !(datafellows & SSH_BUG_GSS_EMPTYUSER)) {
645 packet_put_cstring("");
648 packet_put_cstring(authctxt->server_user);
652 packet_put_cstring(authctxt->service);
653 packet_put_cstring(authctxt->method->name);
661 userauth_none(Authctxt *authctxt)
663 /* initial userauth request */
664 packet_start(SSH2_MSG_USERAUTH_REQUEST);
665 packet_put_cstring(authctxt->server_user);
666 packet_put_cstring(authctxt->service);
667 packet_put_cstring(authctxt->method->name);
674 userauth_passwd(Authctxt *authctxt)
676 static int attempt = 0;
680 if (attempt++ >= options.number_of_password_prompts)
684 error("Permission denied, please try again.");
686 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
687 authctxt->server_user, authctxt->host);
688 password = read_passphrase(prompt, 0);
689 packet_start(SSH2_MSG_USERAUTH_REQUEST);
690 packet_put_cstring(authctxt->server_user);
691 packet_put_cstring(authctxt->service);
692 packet_put_cstring(authctxt->method->name);
694 packet_put_cstring(password);
695 memset(password, 0, strlen(password));
697 packet_add_padding(64);
700 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
701 &input_userauth_passwd_changereq);
706 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
709 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
711 Authctxt *authctxt = ctxt;
712 char *info, *lang, *password = NULL, *retype = NULL;
715 debug2("input_userauth_passwd_changereq");
717 if (authctxt == NULL)
718 fatal("input_userauth_passwd_changereq: "
719 "no authentication context");
721 info = packet_get_string(NULL);
722 lang = packet_get_string(NULL);
723 if (strlen(info) > 0)
727 packet_start(SSH2_MSG_USERAUTH_REQUEST);
728 packet_put_cstring(authctxt->server_user);
729 packet_put_cstring(authctxt->service);
730 packet_put_cstring(authctxt->method->name);
731 packet_put_char(1); /* additional info */
732 snprintf(prompt, sizeof(prompt),
733 "Enter %.30s@%.128s's old password: ",
734 authctxt->server_user, authctxt->host);
735 password = read_passphrase(prompt, 0);
736 packet_put_cstring(password);
737 memset(password, 0, strlen(password));
740 while (password == NULL) {
741 snprintf(prompt, sizeof(prompt),
742 "Enter %.30s@%.128s's new password: ",
743 authctxt->server_user, authctxt->host);
744 password = read_passphrase(prompt, RP_ALLOW_EOF);
745 if (password == NULL) {
749 snprintf(prompt, sizeof(prompt),
750 "Retype %.30s@%.128s's new password: ",
751 authctxt->server_user, authctxt->host);
752 retype = read_passphrase(prompt, 0);
753 if (strcmp(password, retype) != 0) {
754 memset(password, 0, strlen(password));
756 log("Mismatch; try again, EOF to quit.");
759 memset(retype, 0, strlen(retype));
762 packet_put_cstring(password);
763 memset(password, 0, strlen(password));
765 packet_add_padding(64);
768 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
769 &input_userauth_passwd_changereq);
773 clear_auth_state(Authctxt *authctxt)
775 /* XXX clear authentication state */
776 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL);
778 if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) {
779 debug3("clear_auth_state: key_free %p", authctxt->last_key);
780 key_free(authctxt->last_key);
782 authctxt->last_key = NULL;
783 authctxt->last_key_hint = -2;
784 authctxt->last_key_sign = NULL;
788 sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
791 u_char *blob, *signature;
797 debug3("sign_and_send_pubkey");
799 if (key_to_blob(k, &blob, &bloblen) == 0) {
800 /* we cannot handle this key */
801 debug3("sign_and_send_pubkey: cannot handle key");
804 /* data to be signed */
806 if (datafellows & SSH_OLD_SESSIONID) {
807 buffer_append(&b, session_id2, session_id2_len);
808 skip = session_id2_len;
810 buffer_put_string(&b, session_id2, session_id2_len);
811 skip = buffer_len(&b);
813 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
814 buffer_put_cstring(&b, authctxt->server_user);
815 buffer_put_cstring(&b,
816 datafellows & SSH_BUG_PKSERVICE ?
819 if (datafellows & SSH_BUG_PKAUTH) {
820 buffer_put_char(&b, have_sig);
822 buffer_put_cstring(&b, authctxt->method->name);
823 buffer_put_char(&b, have_sig);
824 buffer_put_cstring(&b, key_ssh_name(k));
826 buffer_put_string(&b, blob, bloblen);
828 /* generate signature */
829 ret = (*sign_callback)(authctxt, k, &signature, &slen,
830 buffer_ptr(&b), buffer_len(&b));
839 if (datafellows & SSH_BUG_PKSERVICE) {
841 buffer_append(&b, session_id2, session_id2_len);
842 skip = session_id2_len;
843 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
844 buffer_put_cstring(&b, authctxt->server_user);
845 buffer_put_cstring(&b, authctxt->service);
846 buffer_put_cstring(&b, authctxt->method->name);
847 buffer_put_char(&b, have_sig);
848 if (!(datafellows & SSH_BUG_PKAUTH))
849 buffer_put_cstring(&b, key_ssh_name(k));
850 buffer_put_string(&b, blob, bloblen);
854 /* append signature */
855 buffer_put_string(&b, signature, slen);
858 /* skip session id and packet type */
859 if (buffer_len(&b) < skip + 1)
860 fatal("userauth_pubkey: internal error");
861 buffer_consume(&b, skip + 1);
863 /* put remaining data from buffer into packet */
864 packet_start(SSH2_MSG_USERAUTH_REQUEST);
865 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
873 send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback,
877 u_int bloblen, have_sig = 0;
879 debug3("send_pubkey_test");
881 if (key_to_blob(k, &blob, &bloblen) == 0) {
882 /* we cannot handle this key */
883 debug3("send_pubkey_test: cannot handle key");
886 /* register callback for USERAUTH_PK_OK message */
887 authctxt->last_key_sign = sign_callback;
888 authctxt->last_key_hint = hint;
889 authctxt->last_key = k;
890 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
892 packet_start(SSH2_MSG_USERAUTH_REQUEST);
893 packet_put_cstring(authctxt->server_user);
894 packet_put_cstring(authctxt->service);
895 packet_put_cstring(authctxt->method->name);
896 packet_put_char(have_sig);
897 if (!(datafellows & SSH_BUG_PKAUTH))
898 packet_put_cstring(key_ssh_name(k));
899 packet_put_string(blob, bloblen);
906 load_identity_file(char *filename)
909 char prompt[300], *passphrase;
913 if (stat(filename, &st) < 0) {
914 debug3("no such identity: %s", filename);
917 private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
918 if (private == NULL) {
919 if (options.batch_mode)
921 snprintf(prompt, sizeof prompt,
922 "Enter passphrase for key '%.100s': ", filename);
923 for (i = 0; i < options.number_of_password_prompts; i++) {
924 passphrase = read_passphrase(prompt, 0);
925 if (strcmp(passphrase, "") != 0) {
926 private = key_load_private_type(KEY_UNSPEC, filename,
930 debug2("no passphrase given, try next key");
933 memset(passphrase, 0, strlen(passphrase));
935 if (private != NULL || quit)
937 debug2("bad passphrase given, try again...");
944 identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
945 u_char *data, u_int datalen)
950 idx = authctxt->last_key_hint;
954 /* private key is stored in external hardware */
955 if (options.identity_keys[idx]->flags & KEY_FLAG_EXT)
956 return key_sign(options.identity_keys[idx], sigp, lenp, data, datalen);
958 private = load_identity_file(options.identity_files[idx]);
961 ret = key_sign(private, sigp, lenp, data, datalen);
967 agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
968 u_char *data, u_int datalen)
970 return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen);
974 key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
975 u_char *data, u_int datalen)
977 return key_sign(key, sigp, lenp, data, datalen);
981 userauth_pubkey_agent(Authctxt *authctxt)
983 static int called = 0;
989 if (ssh_get_num_identities(authctxt->agent, 2) == 0)
990 debug2("userauth_pubkey_agent: no keys at all");
993 k = ssh_get_next_identity(authctxt->agent, &comment, 2);
995 debug2("userauth_pubkey_agent: no more keys");
997 debug("userauth_pubkey_agent: testing agent key %s", comment);
999 ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1);
1004 debug2("userauth_pubkey_agent: no message sent");
1009 userauth_pubkey(Authctxt *authctxt)
1016 if (authctxt->agent != NULL) {
1018 sent = userauth_pubkey_agent(authctxt);
1019 } while (!sent && authctxt->agent->howmany > 0);
1021 while (!sent && idx < options.num_identity_files) {
1022 key = options.identity_keys[idx];
1023 filename = options.identity_files[idx];
1025 debug("try privkey: %s", filename);
1026 key = load_identity_file(filename);
1028 sent = sign_and_send_pubkey(authctxt, key,
1032 } else if (key->type != KEY_RSA1) {
1033 debug("try pubkey: %s", filename);
1034 sent = send_pubkey_test(authctxt, key,
1035 identity_sign_cb, idx);
1043 * Send userauth request message specifying keyboard-interactive method.
1046 userauth_kbdint(Authctxt *authctxt)
1048 static int attempt = 0;
1050 if (attempt++ >= options.number_of_password_prompts)
1052 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1053 if (attempt > 1 && !authctxt->info_req_seen) {
1054 debug3("userauth_kbdint: disable: no info_req_seen");
1055 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1059 debug2("userauth_kbdint");
1060 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1061 packet_put_cstring(authctxt->server_user);
1062 packet_put_cstring(authctxt->service);
1063 packet_put_cstring(authctxt->method->name);
1064 packet_put_cstring(""); /* lang */
1065 packet_put_cstring(options.kbd_interactive_devices ?
1066 options.kbd_interactive_devices : "");
1069 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1074 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1077 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1079 Authctxt *authctxt = ctxt;
1080 char *name, *inst, *lang, *prompt, *response;
1081 u_int num_prompts, i;
1084 debug2("input_userauth_info_req");
1086 if (authctxt == NULL)
1087 fatal("input_userauth_info_req: no authentication context");
1089 authctxt->info_req_seen = 1;
1091 name = packet_get_string(NULL);
1092 inst = packet_get_string(NULL);
1093 lang = packet_get_string(NULL);
1094 if (strlen(name) > 0)
1096 if (strlen(inst) > 0)
1102 num_prompts = packet_get_int();
1104 * Begin to build info response packet based on prompts requested.
1105 * We commit to providing the correct number of responses, so if
1106 * further on we run into a problem that prevents this, we have to
1107 * be sure and clean this up and send a correct error response.
1109 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1110 packet_put_int(num_prompts);
1112 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1113 for (i = 0; i < num_prompts; i++) {
1114 prompt = packet_get_string(NULL);
1115 echo = packet_get_char();
1117 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1119 packet_put_cstring(response);
1120 memset(response, 0, strlen(response));
1124 packet_check_eom(); /* done with parsing incoming message. */
1126 packet_add_padding(64);
1131 ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1132 u_char *data, u_int datalen)
1137 int to[2], from[2], status, version = 2;
1139 debug("ssh_keysign called");
1141 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1142 error("ssh_keysign: no installed: %s", strerror(errno));
1145 if (fflush(stdout) != 0)
1146 error("ssh_keysign: fflush: %s", strerror(errno));
1148 error("ssh_keysign: pipe: %s", strerror(errno));
1151 if (pipe(from) < 0) {
1152 error("ssh_keysign: pipe: %s", strerror(errno));
1155 if ((pid = fork()) < 0) {
1156 error("ssh_keysign: fork: %s", strerror(errno));
1163 if (dup2(from[1], STDOUT_FILENO) < 0)
1164 fatal("ssh_keysign: dup2: %s", strerror(errno));
1166 if (dup2(to[0], STDIN_FILENO) < 0)
1167 fatal("ssh_keysign: dup2: %s", strerror(errno));
1170 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1171 fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1178 buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1179 buffer_put_string(&b, data, datalen);
1180 msg_send(to[1], version, &b);
1182 if (msg_recv(from[0], &b) < 0) {
1183 error("ssh_keysign: no reply");
1190 while (waitpid(pid, &status, 0) < 0)
1194 if (buffer_get_char(&b) != version) {
1195 error("ssh_keysign: bad version");
1199 *sigp = buffer_get_string(&b, lenp);
1206 userauth_hostbased(Authctxt *authctxt)
1208 Key *private = NULL;
1209 Sensitive *sensitive = authctxt->sensitive;
1211 u_char *signature, *blob;
1212 char *chost, *pkalg, *p;
1213 const char *service;
1215 int ok, i, len, found = 0;
1217 /* check for a useful key */
1218 for (i = 0; i < sensitive->nkeys; i++) {
1219 private = sensitive->keys[i];
1220 if (private && private->type != KEY_RSA1) {
1222 /* we take and free the key */
1223 sensitive->keys[i] = NULL;
1228 debug("userauth_hostbased: no more client hostkeys");
1231 if (key_to_blob(private, &blob, &blen) == 0) {
1235 /* figure out a name for the client host */
1236 p = get_local_name(packet_get_connection_in());
1238 error("userauth_hostbased: cannot get local ipaddr/name");
1242 len = strlen(p) + 2;
1243 chost = xmalloc(len);
1244 strlcpy(chost, p, len);
1245 strlcat(chost, ".", len);
1246 debug2("userauth_hostbased: chost %s", chost);
1248 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1250 pkalg = xstrdup(key_ssh_name(private));
1252 /* construct data */
1253 buffer_put_string(&b, session_id2, session_id2_len);
1254 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1255 buffer_put_cstring(&b, authctxt->server_user);
1256 buffer_put_cstring(&b, service);
1257 buffer_put_cstring(&b, authctxt->method->name);
1258 buffer_put_cstring(&b, pkalg);
1259 buffer_put_string(&b, blob, blen);
1260 buffer_put_cstring(&b, chost);
1261 buffer_put_cstring(&b, authctxt->local_user);
1265 if (sensitive->external_keysign)
1266 ok = ssh_keysign(private, &signature, &slen,
1267 buffer_ptr(&b), buffer_len(&b));
1269 ok = key_sign(private, &signature, &slen,
1270 buffer_ptr(&b), buffer_len(&b));
1274 error("key_sign failed");
1279 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1280 packet_put_cstring(authctxt->server_user);
1281 packet_put_cstring(authctxt->service);
1282 packet_put_cstring(authctxt->method->name);
1283 packet_put_cstring(pkalg);
1284 packet_put_string(blob, blen);
1285 packet_put_cstring(chost);
1286 packet_put_cstring(authctxt->local_user);
1287 packet_put_string(signature, slen);
1288 memset(signature, 's', slen);
1297 /* find auth method */
1300 * given auth method name, if configurable options permit this method fill
1301 * in auth_ident field and return true, otherwise return false.
1304 authmethod_is_enabled(Authmethod *method)
1308 /* return false if options indicate this method is disabled */
1309 if (method->enabled == NULL || *method->enabled == 0)
1311 /* return false if batch mode is enabled but method needs interactive mode */
1312 if (method->batch_flag != NULL && *method->batch_flag != 0)
1318 authmethod_lookup(const char *name)
1320 Authmethod *method = NULL;
1322 for (method = authmethods; method->name != NULL; method++)
1323 if (strcmp(name, method->name) == 0)
1325 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1329 /* XXX internal state */
1330 static Authmethod *current = NULL;
1331 static char *supported = NULL;
1332 static char *preferred = NULL;
1335 * Given the authentication method list sent by the server, return the
1336 * next method we should try. If the server initially sends a nil list,
1337 * use a built-in default list.
1340 authmethod_get(char *authlist)
1346 /* Use a suitable default if we're passed a nil list. */
1347 if (authlist == NULL || strlen(authlist) == 0)
1348 authlist = options.preferred_authentications;
1350 if (supported == NULL || strcmp(authlist, supported) != 0) {
1351 debug3("start over, passed a different list %s", authlist);
1352 if (supported != NULL)
1354 supported = xstrdup(authlist);
1355 preferred = options.preferred_authentications;
1356 debug3("preferred %s", preferred);
1358 } else if (current != NULL && authmethod_is_enabled(current))
1362 if ((name = match_list(preferred, supported, &next)) == NULL) {
1363 debug("no more auth methods to try");
1368 debug3("authmethod_lookup %s", name);
1369 debug3("remaining preferred: %s", preferred);
1370 if ((current = authmethod_lookup(name)) != NULL &&
1371 authmethod_is_enabled(current)) {
1372 debug3("authmethod_is_enabled %s", name);
1373 debug("next auth method to try is %s", name);
1380 authmethods_get(void)
1382 Authmethod *method = NULL;
1387 for (method = authmethods; method->name != NULL; method++) {
1388 if (authmethod_is_enabled(method)) {
1389 if (buffer_len(&b) > 0)
1390 buffer_append(&b, ",", 1);
1391 buffer_append(&b, method->name, strlen(method->name));
1394 buffer_append(&b, "\0", 1);
1395 list = xstrdup(buffer_ptr(&b));