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 1.121 2003/08/22 10:56:09 markus Exp $");
31 #define krb5_get_err_text(context,code) error_message(code)
35 #include "openbsd-compat/sys-queue.h"
46 #include "myproposal.h"
47 #include "sshconnect.h"
58 #include "pathnames.h"
65 extern char *client_version_string;
66 extern char *server_version_string;
67 extern Options options;
73 u_char *session_id2 = NULL;
74 u_int session_id2_len = 0;
77 struct sockaddr *xxx_hostaddr;
82 verify_host_key_callback(Key *hostkey)
84 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
85 fatal("Host key verification failed.");
90 ssh_kex2(char *host, struct sockaddr *hostaddr)
95 xxx_hostaddr = hostaddr;
97 if (options.ciphers == (char *)-1) {
98 logit("No valid ciphers for protocol version 2 given, using defaults.");
99 options.ciphers = NULL;
101 if (options.ciphers != NULL) {
102 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
103 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
105 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
106 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
107 myproposal[PROPOSAL_ENC_ALGS_STOC] =
108 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
109 if (options.compression) {
110 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
111 myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none";
113 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
114 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib";
116 if (options.macs != NULL) {
117 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
118 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
120 if (options.hostkeyalgorithms != NULL)
121 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
122 options.hostkeyalgorithms;
124 if (options.rekey_limit)
125 packet_set_rekey_limit(options.rekey_limit);
127 /* start key exchange */
128 kex = kex_setup(myproposal);
129 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
130 kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
131 kex->client_version_string=client_version_string;
132 kex->server_version_string=server_version_string;
133 kex->verify_host_key=&verify_host_key_callback;
137 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
139 session_id2 = kex->session_id;
140 session_id2_len = kex->session_id_len;
143 /* send 1st encrypted/maced/compressed message */
144 packet_start(SSH2_MSG_IGNORE);
145 packet_put_cstring("markus");
155 typedef struct Authctxt Authctxt;
156 typedef struct Authmethod Authmethod;
157 typedef struct identity Identity;
158 typedef struct idlist Idlist;
161 TAILQ_ENTRY(identity) next;
162 AuthenticationConnection *ac; /* set if agent supports key */
163 Key *key; /* public/private key */
164 char *filename; /* comment for agent-only keys */
166 int isprivate; /* key points to the private key */
168 TAILQ_HEAD(idlist, identity);
171 const char *server_user;
172 const char *local_user;
180 AuthenticationConnection *agent;
182 Sensitive *sensitive;
183 /* kbd-interactive */
189 char *name; /* string to compare against server's list */
190 int (*userauth)(Authctxt *authctxt);
191 int *enabled; /* flag in option struct that enables method */
192 int *batch_flag; /* flag in option struct that disables method */
195 void input_userauth_success(int, u_int32_t, void *);
196 void input_userauth_failure(int, u_int32_t, void *);
197 void input_userauth_banner(int, u_int32_t, void *);
198 void input_userauth_error(int, u_int32_t, void *);
199 void input_userauth_info_req(int, u_int32_t, void *);
200 void input_userauth_pk_ok(int, u_int32_t, void *);
201 void input_userauth_passwd_changereq(int, u_int32_t, void *);
203 int userauth_none(Authctxt *);
204 int userauth_pubkey(Authctxt *);
205 int userauth_passwd(Authctxt *);
206 int userauth_kbdint(Authctxt *);
207 int userauth_hostbased(Authctxt *);
208 int userauth_kerberos(Authctxt *);
211 int userauth_gssapi(Authctxt *authctxt);
212 void input_gssapi_response(int type, u_int32_t, void *);
213 void input_gssapi_token(int type, u_int32_t, void *);
214 void input_gssapi_hash(int type, u_int32_t, void *);
215 void input_gssapi_error(int, u_int32_t, void *);
216 void input_gssapi_errtok(int, u_int32_t, void *);
219 void userauth(Authctxt *, char *);
221 static int sign_and_send_pubkey(Authctxt *, Identity *);
222 static void pubkey_prepare(Authctxt *);
223 static void pubkey_cleanup(Authctxt *);
224 static Key *load_identity_file(char *);
226 static Authmethod *authmethod_get(char *authlist);
227 static Authmethod *authmethod_lookup(const char *name);
228 static char *authmethods_get(void);
230 Authmethod authmethods[] = {
234 &options.gss_authentication,
239 &options.hostbased_authentication,
242 {"kerberos-2@ssh.com",
244 &options.kerberos_authentication,
249 &options.pubkey_authentication,
251 {"keyboard-interactive",
253 &options.kbd_interactive_authentication,
254 &options.batch_mode},
257 &options.password_authentication,
258 &options.batch_mode},
263 {NULL, NULL, NULL, NULL}
267 ssh_userauth2(const char *local_user, const char *server_user, char *host,
268 Sensitive *sensitive)
273 if (options.challenge_response_authentication)
274 options.kbd_interactive_authentication = 1;
276 packet_start(SSH2_MSG_SERVICE_REQUEST);
277 packet_put_cstring("ssh-userauth");
279 debug("SSH2_MSG_SERVICE_REQUEST sent");
281 type = packet_read();
282 if (type != SSH2_MSG_SERVICE_ACCEPT)
283 fatal("Server denied authentication request: %d", type);
284 if (packet_remaining() > 0) {
285 char *reply = packet_get_string(NULL);
286 debug2("service_accept: %s", reply);
289 debug2("buggy server: service_accept w/o service");
292 debug("SSH2_MSG_SERVICE_ACCEPT received");
294 if (options.preferred_authentications == NULL)
295 options.preferred_authentications = authmethods_get();
297 /* setup authentication context */
298 memset(&authctxt, 0, sizeof(authctxt));
299 pubkey_prepare(&authctxt);
300 authctxt.server_user = server_user;
301 authctxt.local_user = local_user;
302 authctxt.host = host;
303 authctxt.service = "ssh-connection"; /* service name */
304 authctxt.success = 0;
305 authctxt.method = authmethod_lookup("none");
306 authctxt.authlist = NULL;
307 authctxt.methoddata = NULL;
308 authctxt.sensitive = sensitive;
309 authctxt.info_req_seen = 0;
310 if (authctxt.method == NULL)
311 fatal("ssh_userauth2: internal error: cannot send userauth none request");
313 /* initial userauth request */
314 userauth_none(&authctxt);
316 dispatch_init(&input_userauth_error);
317 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
318 dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
319 dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
320 dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
322 pubkey_cleanup(&authctxt);
323 dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
325 debug("Authentication succeeded (%s).", authctxt.method->name);
329 userauth(Authctxt *authctxt, char *authlist)
331 if (authctxt->methoddata) {
332 xfree(authctxt->methoddata);
333 authctxt->methoddata = NULL;
335 if (authlist == NULL) {
336 authlist = authctxt->authlist;
338 if (authctxt->authlist)
339 xfree(authctxt->authlist);
340 authctxt->authlist = authlist;
343 Authmethod *method = authmethod_get(authlist);
345 fatal("Permission denied (%s).", authlist);
346 authctxt->method = method;
348 /* reset the per method handler */
349 dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
350 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
352 /* and try new method */
353 if (method->userauth(authctxt) != 0) {
354 debug2("we sent a %s packet, wait for reply", method->name);
357 debug2("we did not send a packet, disable method");
358 method->enabled = NULL;
364 input_userauth_error(int type, u_int32_t seq, void *ctxt)
366 fatal("input_userauth_error: bad message during authentication: "
371 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
374 debug3("input_userauth_banner");
375 msg = packet_get_string(NULL);
376 lang = packet_get_string(NULL);
377 fprintf(stderr, "%s", msg);
383 input_userauth_success(int type, u_int32_t seq, void *ctxt)
385 Authctxt *authctxt = ctxt;
386 if (authctxt == NULL)
387 fatal("input_userauth_success: no authentication context");
388 if (authctxt->authlist)
389 xfree(authctxt->authlist);
390 if (authctxt->methoddata)
391 xfree(authctxt->methoddata);
392 authctxt->success = 1; /* break out */
396 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
398 Authctxt *authctxt = ctxt;
399 char *authlist = NULL;
402 if (authctxt == NULL)
403 fatal("input_userauth_failure: no authentication context");
405 authlist = packet_get_string(NULL);
406 partial = packet_get_char();
410 logit("Authenticated with partial success.");
411 debug("Authentications that can continue: %s", authlist);
413 userauth(authctxt, authlist);
416 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
418 Authctxt *authctxt = ctxt;
422 int pktype, sent = 0;
427 if (authctxt == NULL)
428 fatal("input_userauth_pk_ok: no authentication context");
429 if (datafellows & SSH_BUG_PKOK) {
430 /* this is similar to SSH_BUG_PKAUTH */
431 debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
432 pkblob = packet_get_string(&blen);
434 buffer_append(&b, pkblob, blen);
435 pkalg = buffer_get_string(&b, &alen);
438 pkalg = packet_get_string(&alen);
439 pkblob = packet_get_string(&blen);
443 debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
445 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
446 debug("unknown pkalg %s", pkalg);
449 if ((key = key_from_blob(pkblob, blen)) == NULL) {
450 debug("no key from blob. pkalg %s", pkalg);
453 if (key->type != pktype) {
454 error("input_userauth_pk_ok: type mismatch "
455 "for decoded key (received %d, expected %d)",
459 fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
460 debug2("input_userauth_pk_ok: fp %s", fp);
463 TAILQ_FOREACH(id, &authctxt->keys, next) {
464 if (key_equal(key, id->key)) {
465 sent = sign_and_send_pubkey(authctxt, id);
475 /* try another method if we did not send a packet */
477 userauth(authctxt, NULL);
482 userauth_gssapi(Authctxt *authctxt)
484 Gssctxt *gssctxt = NULL;
485 static gss_OID_set supported = NULL;
490 /* Try one GSSAPI method at a time, rather than sending them all at
493 if (supported == NULL)
494 gss_indicate_mechs(&min, &supported);
496 /* Check to see if the mechanism is usable before we offer it */
497 while (mech<supported->count && !ok) {
499 ssh_gssapi_delete_ctx(&gssctxt);
500 ssh_gssapi_build_ctx(&gssctxt);
501 ssh_gssapi_set_oid(gssctxt, &supported->elements[mech]);
503 /* My DER encoding requires length<128 */
504 if (supported->elements[mech].length < 128 &&
505 !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
507 ok = 1; /* Mechanism works */
515 authctxt->methoddata=(void *)gssctxt;
517 packet_start(SSH2_MSG_USERAUTH_REQUEST);
518 packet_put_cstring(authctxt->server_user);
519 packet_put_cstring(authctxt->service);
520 packet_put_cstring(authctxt->method->name);
524 /* Some servers encode the OID incorrectly (as we used to) */
525 if (datafellows & SSH_BUG_GSSAPI_BER) {
526 packet_put_string(supported->elements[mech].elements,
527 supported->elements[mech].length);
529 packet_put_int((supported->elements[mech].length)+2);
530 packet_put_char(SSH_GSS_OIDTYPE);
531 packet_put_char(supported->elements[mech].length);
532 packet_put_raw(supported->elements[mech].elements,
533 supported->elements[mech].length);
538 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
539 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
540 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
541 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
543 mech++; /* Move along to next candidate */
549 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
551 Authctxt *authctxt = ctxt;
553 OM_uint32 status, ms;
556 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
558 if (authctxt == NULL)
559 fatal("input_gssapi_response: no authentication context");
560 gssctxt = authctxt->methoddata;
563 oidv = packet_get_string(&oidlen);
565 if (datafellows & SSH_BUG_GSSAPI_BER) {
566 if (!ssh_gssapi_check_oid(gssctxt, oidv, oidlen))
567 fatal("Server returned different OID than expected");
569 if(oidv[0] != SSH_GSS_OIDTYPE || oidv[1] != oidlen-2) {
570 debug("Badly encoded mechanism OID received");
571 userauth(authctxt, NULL);
575 if (!ssh_gssapi_check_oid(gssctxt, oidv+2, oidlen-2))
576 fatal("Server returned different OID than expected");
583 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
584 GSS_C_NO_BUFFER, &send_tok, NULL);
585 if (GSS_ERROR(status)) {
586 if (send_tok.length > 0) {
587 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
588 packet_put_string(send_tok.value, send_tok.length);
590 gss_release_buffer(&ms, &send_tok);
592 /* Start again with next method on list */
593 debug("Trying to start again");
594 userauth(authctxt, NULL);
598 /* We must have data to send */
599 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
600 packet_put_string(send_tok.value, send_tok.length);
602 gss_release_buffer(&ms, &send_tok);
606 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
608 Authctxt *authctxt = ctxt;
610 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
611 gss_buffer_desc recv_tok;
612 OM_uint32 status, ms;
615 if (authctxt == NULL)
616 fatal("input_gssapi_response: no authentication context");
617 gssctxt = authctxt->methoddata;
619 recv_tok.value = packet_get_string(&slen);
620 recv_tok.length = slen; /* safe typecast */
624 status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
625 &recv_tok, &send_tok, NULL);
627 xfree(recv_tok.value);
629 if (GSS_ERROR(status)) {
630 if (send_tok.length > 0) {
631 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
632 packet_put_string(send_tok.value, send_tok.length);
634 gss_release_buffer(&ms, &send_tok);
636 /* Start again with the next method in the list */
637 userauth(authctxt, NULL);
641 if (send_tok.length > 0) {
642 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
643 packet_put_string(send_tok.value, send_tok.length);
645 gss_release_buffer(&ms, &send_tok);
648 if (status == GSS_S_COMPLETE) {
649 /* If that succeeded, send a exchange complete message */
650 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
656 input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
658 Authctxt *authctxt = ctxt;
660 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
661 gss_buffer_desc recv_tok;
662 OM_uint32 status, ms;
664 if (authctxt == NULL)
665 fatal("input_gssapi_response: no authentication context");
666 gssctxt = authctxt->methoddata;
668 recv_tok.value = packet_get_string(&recv_tok.length);
672 /* Stick it into GSSAPI and see what it says */
673 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
674 &recv_tok, &send_tok, NULL);
676 xfree(recv_tok.value);
677 gss_release_buffer(&ms, &send_tok);
679 /* Server will be returning a failed packet after this one */
683 input_gssapi_error(int type, u_int32_t plen, void *ctxt)
689 maj=packet_get_int();
690 min=packet_get_int();
691 msg=packet_get_string(NULL);
692 lang=packet_get_string(NULL);
696 debug("Server GSSAPI Error:\n%s\n", msg);
703 userauth_none(Authctxt *authctxt)
705 /* initial userauth request */
706 packet_start(SSH2_MSG_USERAUTH_REQUEST);
707 packet_put_cstring(authctxt->server_user);
708 packet_put_cstring(authctxt->service);
709 packet_put_cstring(authctxt->method->name);
715 userauth_passwd(Authctxt *authctxt)
717 static int attempt = 0;
721 if (attempt++ >= options.number_of_password_prompts)
725 error("Permission denied, please try again.");
727 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
728 authctxt->server_user, authctxt->host);
729 password = read_passphrase(prompt, 0);
730 packet_start(SSH2_MSG_USERAUTH_REQUEST);
731 packet_put_cstring(authctxt->server_user);
732 packet_put_cstring(authctxt->service);
733 packet_put_cstring(authctxt->method->name);
735 packet_put_cstring(password);
736 memset(password, 0, strlen(password));
738 packet_add_padding(64);
741 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
742 &input_userauth_passwd_changereq);
747 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
750 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
752 Authctxt *authctxt = ctxt;
753 char *info, *lang, *password = NULL, *retype = NULL;
756 debug2("input_userauth_passwd_changereq");
758 if (authctxt == NULL)
759 fatal("input_userauth_passwd_changereq: "
760 "no authentication context");
762 info = packet_get_string(NULL);
763 lang = packet_get_string(NULL);
764 if (strlen(info) > 0)
768 packet_start(SSH2_MSG_USERAUTH_REQUEST);
769 packet_put_cstring(authctxt->server_user);
770 packet_put_cstring(authctxt->service);
771 packet_put_cstring(authctxt->method->name);
772 packet_put_char(1); /* additional info */
773 snprintf(prompt, sizeof(prompt),
774 "Enter %.30s@%.128s's old password: ",
775 authctxt->server_user, authctxt->host);
776 password = read_passphrase(prompt, 0);
777 packet_put_cstring(password);
778 memset(password, 0, strlen(password));
781 while (password == NULL) {
782 snprintf(prompt, sizeof(prompt),
783 "Enter %.30s@%.128s's new password: ",
784 authctxt->server_user, authctxt->host);
785 password = read_passphrase(prompt, RP_ALLOW_EOF);
786 if (password == NULL) {
790 snprintf(prompt, sizeof(prompt),
791 "Retype %.30s@%.128s's new password: ",
792 authctxt->server_user, authctxt->host);
793 retype = read_passphrase(prompt, 0);
794 if (strcmp(password, retype) != 0) {
795 memset(password, 0, strlen(password));
797 logit("Mismatch; try again, EOF to quit.");
800 memset(retype, 0, strlen(retype));
803 packet_put_cstring(password);
804 memset(password, 0, strlen(password));
806 packet_add_padding(64);
809 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
810 &input_userauth_passwd_changereq);
814 identity_sign(Identity *id, u_char **sigp, u_int *lenp,
815 u_char *data, u_int datalen)
820 /* the agent supports this key */
822 return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
825 * we have already loaded the private key or
826 * the private key is stored in external hardware
828 if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
829 return (key_sign(id->key, sigp, lenp, data, datalen));
830 /* load the private key from the file */
831 if ((prv = load_identity_file(id->filename)) == NULL)
833 ret = key_sign(prv, sigp, lenp, data, datalen);
839 sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
842 u_char *blob, *signature;
848 debug3("sign_and_send_pubkey");
850 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
851 /* we cannot handle this key */
852 debug3("sign_and_send_pubkey: cannot handle key");
855 /* data to be signed */
857 if (datafellows & SSH_OLD_SESSIONID) {
858 buffer_append(&b, session_id2, session_id2_len);
859 skip = session_id2_len;
861 buffer_put_string(&b, session_id2, session_id2_len);
862 skip = buffer_len(&b);
864 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
865 buffer_put_cstring(&b, authctxt->server_user);
866 buffer_put_cstring(&b,
867 datafellows & SSH_BUG_PKSERVICE ?
870 if (datafellows & SSH_BUG_PKAUTH) {
871 buffer_put_char(&b, have_sig);
873 buffer_put_cstring(&b, authctxt->method->name);
874 buffer_put_char(&b, have_sig);
875 buffer_put_cstring(&b, key_ssh_name(id->key));
877 buffer_put_string(&b, blob, bloblen);
879 /* generate signature */
880 ret = identity_sign(id, &signature, &slen,
881 buffer_ptr(&b), buffer_len(&b));
890 if (datafellows & SSH_BUG_PKSERVICE) {
892 buffer_append(&b, session_id2, session_id2_len);
893 skip = session_id2_len;
894 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
895 buffer_put_cstring(&b, authctxt->server_user);
896 buffer_put_cstring(&b, authctxt->service);
897 buffer_put_cstring(&b, authctxt->method->name);
898 buffer_put_char(&b, have_sig);
899 if (!(datafellows & SSH_BUG_PKAUTH))
900 buffer_put_cstring(&b, key_ssh_name(id->key));
901 buffer_put_string(&b, blob, bloblen);
905 /* append signature */
906 buffer_put_string(&b, signature, slen);
909 /* skip session id and packet type */
910 if (buffer_len(&b) < skip + 1)
911 fatal("userauth_pubkey: internal error");
912 buffer_consume(&b, skip + 1);
914 /* put remaining data from buffer into packet */
915 packet_start(SSH2_MSG_USERAUTH_REQUEST);
916 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
924 send_pubkey_test(Authctxt *authctxt, Identity *id)
927 u_int bloblen, have_sig = 0;
929 debug3("send_pubkey_test");
931 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
932 /* we cannot handle this key */
933 debug3("send_pubkey_test: cannot handle key");
936 /* register callback for USERAUTH_PK_OK message */
937 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
939 packet_start(SSH2_MSG_USERAUTH_REQUEST);
940 packet_put_cstring(authctxt->server_user);
941 packet_put_cstring(authctxt->service);
942 packet_put_cstring(authctxt->method->name);
943 packet_put_char(have_sig);
944 if (!(datafellows & SSH_BUG_PKAUTH))
945 packet_put_cstring(key_ssh_name(id->key));
946 packet_put_string(blob, bloblen);
953 load_identity_file(char *filename)
956 char prompt[300], *passphrase;
960 if (stat(filename, &st) < 0) {
961 debug3("no such identity: %s", filename);
964 private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
965 if (private == NULL) {
966 if (options.batch_mode)
968 snprintf(prompt, sizeof prompt,
969 "Enter passphrase for key '%.100s': ", filename);
970 for (i = 0; i < options.number_of_password_prompts; i++) {
971 passphrase = read_passphrase(prompt, 0);
972 if (strcmp(passphrase, "") != 0) {
973 private = key_load_private_type(KEY_UNSPEC, filename,
977 debug2("no passphrase given, try next key");
980 memset(passphrase, 0, strlen(passphrase));
982 if (private != NULL || quit)
984 debug2("bad passphrase given, try again...");
991 * try keys in the following order:
992 * 1. agent keys that are found in the config file
993 * 2. other agent keys
994 * 3. keys that are only listed in the config file
997 pubkey_prepare(Authctxt *authctxt)
1000 Idlist agent, files, *preferred;
1002 AuthenticationConnection *ac;
1006 TAILQ_INIT(&agent); /* keys from the agent */
1007 TAILQ_INIT(&files); /* keys from the config file */
1008 preferred = &authctxt->keys;
1009 TAILQ_INIT(preferred); /* preferred order of keys */
1011 /* list of keys stored in the filesystem */
1012 for (i = 0; i < options.num_identity_files; i++) {
1013 key = options.identity_keys[i];
1014 if (key && key->type == KEY_RSA1)
1016 options.identity_keys[i] = NULL;
1017 id = xmalloc(sizeof(*id));
1018 memset(id, 0, sizeof(*id));
1020 id->filename = xstrdup(options.identity_files[i]);
1021 TAILQ_INSERT_TAIL(&files, id, next);
1023 /* list of keys supported by the agent */
1024 if ((ac = ssh_get_authentication_connection())) {
1025 for (key = ssh_get_first_identity(ac, &comment, 2);
1027 key = ssh_get_next_identity(ac, &comment, 2)) {
1029 TAILQ_FOREACH(id, &files, next) {
1030 /* agent keys from the config file are preferred */
1031 if (key_equal(key, id->key)) {
1034 TAILQ_REMOVE(&files, id, next);
1035 TAILQ_INSERT_TAIL(preferred, id, next);
1042 id = xmalloc(sizeof(*id));
1043 memset(id, 0, sizeof(*id));
1045 id->filename = comment;
1047 TAILQ_INSERT_TAIL(&agent, id, next);
1050 /* append remaining agent keys */
1051 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1052 TAILQ_REMOVE(&agent, id, next);
1053 TAILQ_INSERT_TAIL(preferred, id, next);
1055 authctxt->agent = ac;
1057 /* append remaining keys from the config file */
1058 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1059 TAILQ_REMOVE(&files, id, next);
1060 TAILQ_INSERT_TAIL(preferred, id, next);
1062 TAILQ_FOREACH(id, preferred, next) {
1063 debug2("key: %s (%p)", id->filename, id->key);
1068 pubkey_cleanup(Authctxt *authctxt)
1072 if (authctxt->agent != NULL)
1073 ssh_close_authentication_connection(authctxt->agent);
1074 for (id = TAILQ_FIRST(&authctxt->keys); id;
1075 id = TAILQ_FIRST(&authctxt->keys)) {
1076 TAILQ_REMOVE(&authctxt->keys, id, next);
1080 xfree(id->filename);
1086 userauth_pubkey(Authctxt *authctxt)
1091 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1094 TAILQ_REMOVE(&authctxt->keys, id, next);
1095 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1097 * send a test message if we have the public key. for
1098 * encrypted keys we cannot do this and have to load the
1099 * private key instead
1101 if (id->key && id->key->type != KEY_RSA1) {
1102 debug("Offering public key: %s", id->filename);
1103 sent = send_pubkey_test(authctxt, id);
1104 } else if (id->key == NULL) {
1105 debug("Trying private key: %s", id->filename);
1106 id->key = load_identity_file(id->filename);
1107 if (id->key != NULL) {
1109 sent = sign_and_send_pubkey(authctxt, id);
1121 * Send userauth request message specifying keyboard-interactive method.
1124 userauth_kbdint(Authctxt *authctxt)
1126 static int attempt = 0;
1128 if (attempt++ >= options.number_of_password_prompts)
1130 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1131 if (attempt > 1 && !authctxt->info_req_seen) {
1132 debug3("userauth_kbdint: disable: no info_req_seen");
1133 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1137 debug2("userauth_kbdint");
1138 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1139 packet_put_cstring(authctxt->server_user);
1140 packet_put_cstring(authctxt->service);
1141 packet_put_cstring(authctxt->method->name);
1142 packet_put_cstring(""); /* lang */
1143 packet_put_cstring(options.kbd_interactive_devices ?
1144 options.kbd_interactive_devices : "");
1147 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1152 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1155 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1157 Authctxt *authctxt = ctxt;
1158 char *name, *inst, *lang, *prompt, *response;
1159 u_int num_prompts, i;
1162 debug2("input_userauth_info_req");
1164 if (authctxt == NULL)
1165 fatal("input_userauth_info_req: no authentication context");
1167 authctxt->info_req_seen = 1;
1169 name = packet_get_string(NULL);
1170 inst = packet_get_string(NULL);
1171 lang = packet_get_string(NULL);
1172 if (strlen(name) > 0)
1174 if (strlen(inst) > 0)
1180 num_prompts = packet_get_int();
1182 * Begin to build info response packet based on prompts requested.
1183 * We commit to providing the correct number of responses, so if
1184 * further on we run into a problem that prevents this, we have to
1185 * be sure and clean this up and send a correct error response.
1187 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1188 packet_put_int(num_prompts);
1190 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1191 for (i = 0; i < num_prompts; i++) {
1192 prompt = packet_get_string(NULL);
1193 echo = packet_get_char();
1195 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1197 packet_put_cstring(response);
1198 memset(response, 0, strlen(response));
1202 packet_check_eom(); /* done with parsing incoming message. */
1204 packet_add_padding(64);
1209 ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1210 u_char *data, u_int datalen)
1215 int to[2], from[2], status, version = 2;
1217 debug2("ssh_keysign called");
1219 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1220 error("ssh_keysign: no installed: %s", strerror(errno));
1223 if (fflush(stdout) != 0)
1224 error("ssh_keysign: fflush: %s", strerror(errno));
1226 error("ssh_keysign: pipe: %s", strerror(errno));
1229 if (pipe(from) < 0) {
1230 error("ssh_keysign: pipe: %s", strerror(errno));
1233 if ((pid = fork()) < 0) {
1234 error("ssh_keysign: fork: %s", strerror(errno));
1241 if (dup2(from[1], STDOUT_FILENO) < 0)
1242 fatal("ssh_keysign: dup2: %s", strerror(errno));
1244 if (dup2(to[0], STDIN_FILENO) < 0)
1245 fatal("ssh_keysign: dup2: %s", strerror(errno));
1248 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1249 fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1256 buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1257 buffer_put_string(&b, data, datalen);
1258 ssh_msg_send(to[1], version, &b);
1260 if (ssh_msg_recv(from[0], &b) < 0) {
1261 error("ssh_keysign: no reply");
1268 while (waitpid(pid, &status, 0) < 0)
1272 if (buffer_get_char(&b) != version) {
1273 error("ssh_keysign: bad version");
1277 *sigp = buffer_get_string(&b, lenp);
1284 userauth_hostbased(Authctxt *authctxt)
1286 Key *private = NULL;
1287 Sensitive *sensitive = authctxt->sensitive;
1289 u_char *signature, *blob;
1290 char *chost, *pkalg, *p;
1291 const char *service;
1293 int ok, i, len, found = 0;
1295 /* check for a useful key */
1296 for (i = 0; i < sensitive->nkeys; i++) {
1297 private = sensitive->keys[i];
1298 if (private && private->type != KEY_RSA1) {
1300 /* we take and free the key */
1301 sensitive->keys[i] = NULL;
1306 debug("No more client hostkeys for hostbased authentication.");
1309 if (key_to_blob(private, &blob, &blen) == 0) {
1313 /* figure out a name for the client host */
1314 p = get_local_name(packet_get_connection_in());
1316 error("userauth_hostbased: cannot get local ipaddr/name");
1320 len = strlen(p) + 2;
1321 chost = xmalloc(len);
1322 strlcpy(chost, p, len);
1323 strlcat(chost, ".", len);
1324 debug2("userauth_hostbased: chost %s", chost);
1327 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1329 pkalg = xstrdup(key_ssh_name(private));
1331 /* construct data */
1332 buffer_put_string(&b, session_id2, session_id2_len);
1333 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1334 buffer_put_cstring(&b, authctxt->server_user);
1335 buffer_put_cstring(&b, service);
1336 buffer_put_cstring(&b, authctxt->method->name);
1337 buffer_put_cstring(&b, pkalg);
1338 buffer_put_string(&b, blob, blen);
1339 buffer_put_cstring(&b, chost);
1340 buffer_put_cstring(&b, authctxt->local_user);
1344 if (sensitive->external_keysign)
1345 ok = ssh_keysign(private, &signature, &slen,
1346 buffer_ptr(&b), buffer_len(&b));
1348 ok = key_sign(private, &signature, &slen,
1349 buffer_ptr(&b), buffer_len(&b));
1353 error("key_sign failed");
1358 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1359 packet_put_cstring(authctxt->server_user);
1360 packet_put_cstring(authctxt->service);
1361 packet_put_cstring(authctxt->method->name);
1362 packet_put_cstring(pkalg);
1363 packet_put_string(blob, blen);
1364 packet_put_cstring(chost);
1365 packet_put_cstring(authctxt->local_user);
1366 packet_put_string(signature, slen);
1367 memset(signature, 's', slen);
1378 ssh_krb5_helper(krb5_data *ap, krb5_context *context)
1380 krb5_context xcontext = NULL; /* XXX share with ssh1 */
1381 krb5_auth_context xauth_context = NULL;
1382 krb5_auth_context *auth_context;
1383 krb5_error_code problem;
1386 krb5_ccache ccache = NULL;
1387 const char *remotehost;
1390 memset(ap, 0, sizeof(*ap));
1392 context = &xcontext;
1393 auth_context = &xauth_context;
1395 problem = krb5_init_context(context);
1397 debug("Kerberos v5: krb5_init_context failed");
1402 tkfile = krb5_cc_default_name(*context);
1403 if (strncmp(tkfile, "FILE:", 5) == 0)
1406 if (stat(tkfile, &buf) == 0 && getuid() != buf.st_uid) {
1407 debug("Kerberos v5: could not get default ccache (permission denied).");
1412 problem = krb5_cc_default(*context, &ccache);
1414 debug("Kerberos v5: krb5_cc_default failed: %s",
1415 krb5_get_err_text(*context, problem));
1420 remotehost = get_canonical_hostname(1);
1422 problem = krb5_mk_req(*context, auth_context, AP_OPTS_MUTUAL_REQUIRED,
1423 "host", remotehost, NULL, ccache, ap);
1425 debug("Kerberos v5: krb5_mk_req failed: %s",
1426 krb5_get_err_text(*context, problem));
1434 krb5_cc_close(*context, ccache);
1436 krb5_auth_con_free(*context, *auth_context);
1441 userauth_kerberos(Authctxt *authctxt)
1444 krb5_context *context;
1447 if (ssh_krb5_helper(&ap, context) == 0)
1450 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1451 packet_put_cstring(authctxt->server_user);
1452 packet_put_cstring(authctxt->service);
1453 packet_put_cstring(authctxt->method->name);
1454 packet_put_string(ap.data, ap.length);
1458 krb5_data_free(&ap);
1460 krb5_free_data_contents(*context, &ap);
1466 krb5_free_context(*context);
1471 /* find auth method */
1474 * given auth method name, if configurable options permit this method fill
1475 * in auth_ident field and return true, otherwise return false.
1478 authmethod_is_enabled(Authmethod *method)
1482 /* return false if options indicate this method is disabled */
1483 if (method->enabled == NULL || *method->enabled == 0)
1485 /* return false if batch mode is enabled but method needs interactive mode */
1486 if (method->batch_flag != NULL && *method->batch_flag != 0)
1492 authmethod_lookup(const char *name)
1494 Authmethod *method = NULL;
1496 for (method = authmethods; method->name != NULL; method++)
1497 if (strcmp(name, method->name) == 0)
1499 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1503 /* XXX internal state */
1504 static Authmethod *current = NULL;
1505 static char *supported = NULL;
1506 static char *preferred = NULL;
1509 * Given the authentication method list sent by the server, return the
1510 * next method we should try. If the server initially sends a nil list,
1511 * use a built-in default list.
1514 authmethod_get(char *authlist)
1519 /* Use a suitable default if we're passed a nil list. */
1520 if (authlist == NULL || strlen(authlist) == 0)
1521 authlist = options.preferred_authentications;
1523 if (supported == NULL || strcmp(authlist, supported) != 0) {
1524 debug3("start over, passed a different list %s", authlist);
1525 if (supported != NULL)
1527 supported = xstrdup(authlist);
1528 preferred = options.preferred_authentications;
1529 debug3("preferred %s", preferred);
1531 } else if (current != NULL && authmethod_is_enabled(current))
1535 if ((name = match_list(preferred, supported, &next)) == NULL) {
1536 debug("No more authentication methods to try.");
1541 debug3("authmethod_lookup %s", name);
1542 debug3("remaining preferred: %s", preferred);
1543 if ((current = authmethod_lookup(name)) != NULL &&
1544 authmethod_is_enabled(current)) {
1545 debug3("authmethod_is_enabled %s", name);
1546 debug("Next authentication method: %s", name);
1553 authmethods_get(void)
1555 Authmethod *method = NULL;
1560 for (method = authmethods; method->name != NULL; method++) {
1561 if (authmethod_is_enabled(method)) {
1562 if (buffer_len(&b) > 0)
1563 buffer_append(&b, ",", 1);
1564 buffer_append(&b, method->name, strlen(method->name));
1567 buffer_append(&b, "\0", 1);
1568 list = xstrdup(buffer_ptr(&b));