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 1.144 2006/02/07 01:18:09 stevesk Exp $");
28 #include <sys/queue.h>
30 #include "openbsd-compat/sys-queue.h"
41 #include "myproposal.h"
42 #include "sshconnect.h"
53 #include "pathnames.h"
60 extern char *client_version_string;
61 extern char *server_version_string;
62 extern Options options;
68 u_char *session_id2 = NULL;
69 u_int session_id2_len = 0;
72 struct sockaddr *xxx_hostaddr;
77 verify_host_key_callback(Key *hostkey)
79 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
80 fatal("Host key verification failed.");
85 ssh_kex2(char *host, struct sockaddr *hostaddr)
90 xxx_hostaddr = hostaddr;
92 if (options.ciphers == (char *)-1) {
93 logit("No valid ciphers for protocol version 2 given, using defaults.");
94 options.ciphers = NULL;
96 if (options.ciphers != NULL) {
97 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
98 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
100 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
101 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
102 myproposal[PROPOSAL_ENC_ALGS_STOC] =
103 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
104 if (options.compression) {
105 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
106 myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
108 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
109 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
111 if (options.macs != NULL) {
112 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
113 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
115 if (options.hostkeyalgorithms != NULL)
116 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
117 options.hostkeyalgorithms;
119 if (options.rekey_limit)
120 packet_set_rekey_limit(options.rekey_limit);
122 /* start key exchange */
123 kex = kex_setup(myproposal);
124 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
125 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
126 kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
127 kex->client_version_string=client_version_string;
128 kex->server_version_string=server_version_string;
129 kex->verify_host_key=&verify_host_key_callback;
133 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
135 session_id2 = kex->session_id;
136 session_id2_len = kex->session_id_len;
139 /* send 1st encrypted/maced/compressed message */
140 packet_start(SSH2_MSG_IGNORE);
141 packet_put_cstring("markus");
151 typedef struct Authctxt Authctxt;
152 typedef struct Authmethod Authmethod;
153 typedef struct identity Identity;
154 typedef struct idlist Idlist;
157 TAILQ_ENTRY(identity) next;
158 AuthenticationConnection *ac; /* set if agent supports key */
159 Key *key; /* public/private key */
160 char *filename; /* comment for agent-only keys */
162 int isprivate; /* key points to the private key */
164 TAILQ_HEAD(idlist, identity);
167 const char *server_user;
168 const char *local_user;
176 AuthenticationConnection *agent;
178 Sensitive *sensitive;
179 /* kbd-interactive */
185 char *name; /* string to compare against server's list */
186 int (*userauth)(Authctxt *authctxt);
187 int *enabled; /* flag in option struct that enables method */
188 int *batch_flag; /* flag in option struct that disables method */
191 void input_userauth_success(int, u_int32_t, void *);
192 void input_userauth_failure(int, u_int32_t, void *);
193 void input_userauth_banner(int, u_int32_t, void *);
194 void input_userauth_error(int, u_int32_t, void *);
195 void input_userauth_info_req(int, u_int32_t, void *);
196 void input_userauth_pk_ok(int, u_int32_t, void *);
197 void input_userauth_passwd_changereq(int, u_int32_t, void *);
199 int userauth_none(Authctxt *);
200 int userauth_pubkey(Authctxt *);
201 int userauth_passwd(Authctxt *);
202 int userauth_kbdint(Authctxt *);
203 int userauth_hostbased(Authctxt *);
204 int userauth_kerberos(Authctxt *);
207 int userauth_gssapi(Authctxt *authctxt);
208 void input_gssapi_response(int type, u_int32_t, void *);
209 void input_gssapi_token(int type, u_int32_t, void *);
210 void input_gssapi_hash(int type, u_int32_t, void *);
211 void input_gssapi_error(int, u_int32_t, void *);
212 void input_gssapi_errtok(int, u_int32_t, void *);
215 void userauth(Authctxt *, char *);
217 static int sign_and_send_pubkey(Authctxt *, Identity *);
218 static void pubkey_prepare(Authctxt *);
219 static void pubkey_cleanup(Authctxt *);
220 static Key *load_identity_file(char *);
222 static Authmethod *authmethod_get(char *authlist);
223 static Authmethod *authmethod_lookup(const char *name);
224 static char *authmethods_get(void);
226 Authmethod authmethods[] = {
230 &options.gss_authentication,
235 &options.hostbased_authentication,
239 &options.pubkey_authentication,
241 {"keyboard-interactive",
243 &options.kbd_interactive_authentication,
244 &options.batch_mode},
247 &options.password_authentication,
248 &options.batch_mode},
253 {NULL, NULL, NULL, NULL}
257 ssh_userauth2(const char *local_user, const char *server_user, char *host,
258 Sensitive *sensitive)
263 if (options.challenge_response_authentication)
264 options.kbd_interactive_authentication = 1;
266 packet_start(SSH2_MSG_SERVICE_REQUEST);
267 packet_put_cstring("ssh-userauth");
269 debug("SSH2_MSG_SERVICE_REQUEST sent");
271 type = packet_read();
272 if (type != SSH2_MSG_SERVICE_ACCEPT)
273 fatal("Server denied authentication request: %d", type);
274 if (packet_remaining() > 0) {
275 char *reply = packet_get_string(NULL);
276 debug2("service_accept: %s", reply);
279 debug2("buggy server: service_accept w/o service");
282 debug("SSH2_MSG_SERVICE_ACCEPT received");
284 if (options.preferred_authentications == NULL)
285 options.preferred_authentications = authmethods_get();
287 /* setup authentication context */
288 memset(&authctxt, 0, sizeof(authctxt));
289 pubkey_prepare(&authctxt);
290 authctxt.server_user = server_user;
291 authctxt.local_user = local_user;
292 authctxt.host = host;
293 authctxt.service = "ssh-connection"; /* service name */
294 authctxt.success = 0;
295 authctxt.method = authmethod_lookup("none");
296 authctxt.authlist = NULL;
297 authctxt.methoddata = NULL;
298 authctxt.sensitive = sensitive;
299 authctxt.info_req_seen = 0;
300 if (authctxt.method == NULL)
301 fatal("ssh_userauth2: internal error: cannot send userauth none request");
303 /* initial userauth request */
304 userauth_none(&authctxt);
306 dispatch_init(&input_userauth_error);
307 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
308 dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
309 dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
310 dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
312 pubkey_cleanup(&authctxt);
313 dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
315 debug("Authentication succeeded (%s).", authctxt.method->name);
319 userauth(Authctxt *authctxt, char *authlist)
321 if (authctxt->methoddata) {
322 xfree(authctxt->methoddata);
323 authctxt->methoddata = NULL;
325 if (authlist == NULL) {
326 authlist = authctxt->authlist;
328 if (authctxt->authlist)
329 xfree(authctxt->authlist);
330 authctxt->authlist = authlist;
333 Authmethod *method = authmethod_get(authlist);
335 fatal("Permission denied (%s).", authlist);
336 authctxt->method = method;
338 /* reset the per method handler */
339 dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
340 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
342 /* and try new method */
343 if (method->userauth(authctxt) != 0) {
344 debug2("we sent a %s packet, wait for reply", method->name);
347 debug2("we did not send a packet, disable method");
348 method->enabled = NULL;
354 input_userauth_error(int type, u_int32_t seq, void *ctxt)
356 fatal("input_userauth_error: bad message during authentication: "
361 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
365 debug3("input_userauth_banner");
366 msg = packet_get_string(NULL);
367 lang = packet_get_string(NULL);
368 if (options.log_level > SYSLOG_LEVEL_QUIET)
369 fprintf(stderr, "%s", msg);
375 input_userauth_success(int type, u_int32_t seq, void *ctxt)
377 Authctxt *authctxt = ctxt;
378 if (authctxt == NULL)
379 fatal("input_userauth_success: no authentication context");
380 if (authctxt->authlist) {
381 xfree(authctxt->authlist);
382 authctxt->authlist = NULL;
384 if (authctxt->methoddata) {
385 xfree(authctxt->methoddata);
386 authctxt->methoddata = NULL;
388 authctxt->success = 1; /* break out */
392 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
394 Authctxt *authctxt = ctxt;
395 char *authlist = NULL;
398 if (authctxt == NULL)
399 fatal("input_userauth_failure: no authentication context");
401 authlist = packet_get_string(NULL);
402 partial = packet_get_char();
406 logit("Authenticated with partial success.");
407 debug("Authentications that can continue: %s", authlist);
409 userauth(authctxt, authlist);
412 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
414 Authctxt *authctxt = ctxt;
418 int pktype, sent = 0;
423 if (authctxt == NULL)
424 fatal("input_userauth_pk_ok: no authentication context");
425 if (datafellows & SSH_BUG_PKOK) {
426 /* this is similar to SSH_BUG_PKAUTH */
427 debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
428 pkblob = packet_get_string(&blen);
430 buffer_append(&b, pkblob, blen);
431 pkalg = buffer_get_string(&b, &alen);
434 pkalg = packet_get_string(&alen);
435 pkblob = packet_get_string(&blen);
439 debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
441 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
442 debug("unknown pkalg %s", pkalg);
445 if ((key = key_from_blob(pkblob, blen)) == NULL) {
446 debug("no key from blob. pkalg %s", pkalg);
449 if (key->type != pktype) {
450 error("input_userauth_pk_ok: type mismatch "
451 "for decoded key (received %d, expected %d)",
455 fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
456 debug2("input_userauth_pk_ok: fp %s", fp);
460 * search keys in the reverse order, because last candidate has been
461 * moved to the end of the queue. this also avoids confusion by
464 TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
465 if (key_equal(key, id->key)) {
466 sent = sign_and_send_pubkey(authctxt, id);
476 /* try another method if we did not send a packet */
478 userauth(authctxt, NULL);
483 userauth_gssapi(Authctxt *authctxt)
485 Gssctxt *gssctxt = NULL;
486 static gss_OID_set gss_supported = NULL;
487 static u_int mech = 0;
491 /* Try one GSSAPI method at a time, rather than sending them all at
494 if (gss_supported == NULL)
495 gss_indicate_mechs(&min, &gss_supported);
497 /* Check to see if the mechanism is usable before we offer it */
498 while (mech < gss_supported->count && !ok) {
500 ssh_gssapi_delete_ctx(&gssctxt);
501 ssh_gssapi_build_ctx(&gssctxt);
502 ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]);
504 /* My DER encoding requires length<128 */
505 if (gss_supported->elements[mech].length < 128 &&
506 !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
508 ok = 1; /* Mechanism works */
517 authctxt->methoddata=(void *)gssctxt;
519 packet_start(SSH2_MSG_USERAUTH_REQUEST);
520 packet_put_cstring(authctxt->server_user);
521 packet_put_cstring(authctxt->service);
522 packet_put_cstring(authctxt->method->name);
526 packet_put_int((gss_supported->elements[mech].length) + 2);
527 packet_put_char(SSH_GSS_OIDTYPE);
528 packet_put_char(gss_supported->elements[mech].length);
529 packet_put_raw(gss_supported->elements[mech].elements,
530 gss_supported->elements[mech].length);
534 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
535 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
536 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
537 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
539 mech++; /* Move along to next candidate */
545 process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
547 Authctxt *authctxt = ctxt;
548 Gssctxt *gssctxt = authctxt->methoddata;
549 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
550 gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
551 gss_buffer_desc gssbuf;
552 OM_uint32 status, ms, flags;
555 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
556 recv_tok, &send_tok, &flags);
558 if (send_tok.length > 0) {
559 if (GSS_ERROR(status))
560 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
562 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
564 packet_put_string(send_tok.value, send_tok.length);
566 gss_release_buffer(&ms, &send_tok);
569 if (status == GSS_S_COMPLETE) {
570 /* send either complete or MIC, depending on mechanism */
571 if (!(flags & GSS_C_INTEG_FLAG)) {
572 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
575 ssh_gssapi_buildmic(&b, authctxt->server_user,
576 authctxt->service, "gssapi-with-mic");
578 gssbuf.value = buffer_ptr(&b);
579 gssbuf.length = buffer_len(&b);
581 status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
583 if (!GSS_ERROR(status)) {
584 packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
585 packet_put_string(mic.value, mic.length);
591 gss_release_buffer(&ms, &mic);
599 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
601 Authctxt *authctxt = ctxt;
606 if (authctxt == NULL)
607 fatal("input_gssapi_response: no authentication context");
608 gssctxt = authctxt->methoddata;
611 oidv = packet_get_string(&oidlen);
614 oidv[0] != SSH_GSS_OIDTYPE ||
615 oidv[1] != oidlen - 2) {
617 debug("Badly encoded mechanism OID received");
618 userauth(authctxt, NULL);
622 if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
623 fatal("Server returned different OID than expected");
629 if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
630 /* Start again with next method on list */
631 debug("Trying to start again");
632 userauth(authctxt, NULL);
638 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
640 Authctxt *authctxt = ctxt;
641 gss_buffer_desc recv_tok;
645 if (authctxt == NULL)
646 fatal("input_gssapi_response: no authentication context");
648 recv_tok.value = packet_get_string(&slen);
649 recv_tok.length = slen; /* safe typecast */
653 status = process_gssapi_token(ctxt, &recv_tok);
655 xfree(recv_tok.value);
657 if (GSS_ERROR(status)) {
658 /* Start again with the next method in the list */
659 userauth(authctxt, NULL);
665 input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
667 Authctxt *authctxt = ctxt;
669 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
670 gss_buffer_desc recv_tok;
671 OM_uint32 status, ms;
674 if (authctxt == NULL)
675 fatal("input_gssapi_response: no authentication context");
676 gssctxt = authctxt->methoddata;
678 recv_tok.value = packet_get_string(&len);
679 recv_tok.length = len;
683 /* Stick it into GSSAPI and see what it says */
684 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
685 &recv_tok, &send_tok, NULL);
687 xfree(recv_tok.value);
688 gss_release_buffer(&ms, &send_tok);
690 /* Server will be returning a failed packet after this one */
694 input_gssapi_error(int type, u_int32_t plen, void *ctxt)
700 maj=packet_get_int();
701 min=packet_get_int();
702 msg=packet_get_string(NULL);
703 lang=packet_get_string(NULL);
707 debug("Server GSSAPI Error:\n%s", msg);
714 userauth_none(Authctxt *authctxt)
716 /* initial userauth request */
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);
726 userauth_passwd(Authctxt *authctxt)
728 static int attempt = 0;
732 if (attempt++ >= options.number_of_password_prompts)
736 error("Permission denied, please try again.");
738 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
739 authctxt->server_user, authctxt->host);
740 password = read_passphrase(prompt, 0);
741 packet_start(SSH2_MSG_USERAUTH_REQUEST);
742 packet_put_cstring(authctxt->server_user);
743 packet_put_cstring(authctxt->service);
744 packet_put_cstring(authctxt->method->name);
746 packet_put_cstring(password);
747 memset(password, 0, strlen(password));
749 packet_add_padding(64);
752 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
753 &input_userauth_passwd_changereq);
758 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
761 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
763 Authctxt *authctxt = ctxt;
764 char *info, *lang, *password = NULL, *retype = NULL;
767 debug2("input_userauth_passwd_changereq");
769 if (authctxt == NULL)
770 fatal("input_userauth_passwd_changereq: "
771 "no authentication context");
773 info = packet_get_string(NULL);
774 lang = packet_get_string(NULL);
775 if (strlen(info) > 0)
779 packet_start(SSH2_MSG_USERAUTH_REQUEST);
780 packet_put_cstring(authctxt->server_user);
781 packet_put_cstring(authctxt->service);
782 packet_put_cstring(authctxt->method->name);
783 packet_put_char(1); /* additional info */
784 snprintf(prompt, sizeof(prompt),
785 "Enter %.30s@%.128s's old password: ",
786 authctxt->server_user, authctxt->host);
787 password = read_passphrase(prompt, 0);
788 packet_put_cstring(password);
789 memset(password, 0, strlen(password));
792 while (password == NULL) {
793 snprintf(prompt, sizeof(prompt),
794 "Enter %.30s@%.128s's new password: ",
795 authctxt->server_user, authctxt->host);
796 password = read_passphrase(prompt, RP_ALLOW_EOF);
797 if (password == NULL) {
801 snprintf(prompt, sizeof(prompt),
802 "Retype %.30s@%.128s's new password: ",
803 authctxt->server_user, authctxt->host);
804 retype = read_passphrase(prompt, 0);
805 if (strcmp(password, retype) != 0) {
806 memset(password, 0, strlen(password));
808 logit("Mismatch; try again, EOF to quit.");
811 memset(retype, 0, strlen(retype));
814 packet_put_cstring(password);
815 memset(password, 0, strlen(password));
817 packet_add_padding(64);
820 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
821 &input_userauth_passwd_changereq);
825 identity_sign(Identity *id, u_char **sigp, u_int *lenp,
826 u_char *data, u_int datalen)
831 /* the agent supports this key */
833 return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
836 * we have already loaded the private key or
837 * the private key is stored in external hardware
839 if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
840 return (key_sign(id->key, sigp, lenp, data, datalen));
841 /* load the private key from the file */
842 if ((prv = load_identity_file(id->filename)) == NULL)
844 ret = key_sign(prv, sigp, lenp, data, datalen);
850 sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
853 u_char *blob, *signature;
859 debug3("sign_and_send_pubkey");
861 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
862 /* we cannot handle this key */
863 debug3("sign_and_send_pubkey: cannot handle key");
866 /* data to be signed */
868 if (datafellows & SSH_OLD_SESSIONID) {
869 buffer_append(&b, session_id2, session_id2_len);
870 skip = session_id2_len;
872 buffer_put_string(&b, session_id2, session_id2_len);
873 skip = buffer_len(&b);
875 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
876 buffer_put_cstring(&b, authctxt->server_user);
877 buffer_put_cstring(&b,
878 datafellows & SSH_BUG_PKSERVICE ?
881 if (datafellows & SSH_BUG_PKAUTH) {
882 buffer_put_char(&b, have_sig);
884 buffer_put_cstring(&b, authctxt->method->name);
885 buffer_put_char(&b, have_sig);
886 buffer_put_cstring(&b, key_ssh_name(id->key));
888 buffer_put_string(&b, blob, bloblen);
890 /* generate signature */
891 ret = identity_sign(id, &signature, &slen,
892 buffer_ptr(&b), buffer_len(&b));
901 if (datafellows & SSH_BUG_PKSERVICE) {
903 buffer_append(&b, session_id2, session_id2_len);
904 skip = session_id2_len;
905 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
906 buffer_put_cstring(&b, authctxt->server_user);
907 buffer_put_cstring(&b, authctxt->service);
908 buffer_put_cstring(&b, authctxt->method->name);
909 buffer_put_char(&b, have_sig);
910 if (!(datafellows & SSH_BUG_PKAUTH))
911 buffer_put_cstring(&b, key_ssh_name(id->key));
912 buffer_put_string(&b, blob, bloblen);
916 /* append signature */
917 buffer_put_string(&b, signature, slen);
920 /* skip session id and packet type */
921 if (buffer_len(&b) < skip + 1)
922 fatal("userauth_pubkey: internal error");
923 buffer_consume(&b, skip + 1);
925 /* put remaining data from buffer into packet */
926 packet_start(SSH2_MSG_USERAUTH_REQUEST);
927 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
935 send_pubkey_test(Authctxt *authctxt, Identity *id)
938 u_int bloblen, have_sig = 0;
940 debug3("send_pubkey_test");
942 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
943 /* we cannot handle this key */
944 debug3("send_pubkey_test: cannot handle key");
947 /* register callback for USERAUTH_PK_OK message */
948 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
950 packet_start(SSH2_MSG_USERAUTH_REQUEST);
951 packet_put_cstring(authctxt->server_user);
952 packet_put_cstring(authctxt->service);
953 packet_put_cstring(authctxt->method->name);
954 packet_put_char(have_sig);
955 if (!(datafellows & SSH_BUG_PKAUTH))
956 packet_put_cstring(key_ssh_name(id->key));
957 packet_put_string(blob, bloblen);
964 load_identity_file(char *filename)
967 char prompt[300], *passphrase;
971 if (stat(filename, &st) < 0) {
972 debug3("no such identity: %s", filename);
975 private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
976 if (private == NULL) {
977 if (options.batch_mode)
979 snprintf(prompt, sizeof prompt,
980 "Enter passphrase for key '%.100s': ", filename);
981 for (i = 0; i < options.number_of_password_prompts; i++) {
982 passphrase = read_passphrase(prompt, 0);
983 if (strcmp(passphrase, "") != 0) {
984 private = key_load_private_type(KEY_UNSPEC, filename,
988 debug2("no passphrase given, try next key");
991 memset(passphrase, 0, strlen(passphrase));
993 if (private != NULL || quit)
995 debug2("bad passphrase given, try again...");
1002 * try keys in the following order:
1003 * 1. agent keys that are found in the config file
1004 * 2. other agent keys
1005 * 3. keys that are only listed in the config file
1008 pubkey_prepare(Authctxt *authctxt)
1011 Idlist agent, files, *preferred;
1013 AuthenticationConnection *ac;
1017 TAILQ_INIT(&agent); /* keys from the agent */
1018 TAILQ_INIT(&files); /* keys from the config file */
1019 preferred = &authctxt->keys;
1020 TAILQ_INIT(preferred); /* preferred order of keys */
1022 /* list of keys stored in the filesystem */
1023 for (i = 0; i < options.num_identity_files; i++) {
1024 key = options.identity_keys[i];
1025 if (key && key->type == KEY_RSA1)
1027 options.identity_keys[i] = NULL;
1028 id = xmalloc(sizeof(*id));
1029 memset(id, 0, sizeof(*id));
1031 id->filename = xstrdup(options.identity_files[i]);
1032 TAILQ_INSERT_TAIL(&files, id, next);
1034 /* list of keys supported by the agent */
1035 if ((ac = ssh_get_authentication_connection())) {
1036 for (key = ssh_get_first_identity(ac, &comment, 2);
1038 key = ssh_get_next_identity(ac, &comment, 2)) {
1040 TAILQ_FOREACH(id, &files, next) {
1041 /* agent keys from the config file are preferred */
1042 if (key_equal(key, id->key)) {
1045 TAILQ_REMOVE(&files, id, next);
1046 TAILQ_INSERT_TAIL(preferred, id, next);
1052 if (!found && !options.identities_only) {
1053 id = xmalloc(sizeof(*id));
1054 memset(id, 0, sizeof(*id));
1056 id->filename = comment;
1058 TAILQ_INSERT_TAIL(&agent, id, next);
1061 /* append remaining agent keys */
1062 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1063 TAILQ_REMOVE(&agent, id, next);
1064 TAILQ_INSERT_TAIL(preferred, id, next);
1066 authctxt->agent = ac;
1068 /* append remaining keys from the config file */
1069 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1070 TAILQ_REMOVE(&files, id, next);
1071 TAILQ_INSERT_TAIL(preferred, id, next);
1073 TAILQ_FOREACH(id, preferred, next) {
1074 debug2("key: %s (%p)", id->filename, id->key);
1079 pubkey_cleanup(Authctxt *authctxt)
1083 if (authctxt->agent != NULL)
1084 ssh_close_authentication_connection(authctxt->agent);
1085 for (id = TAILQ_FIRST(&authctxt->keys); id;
1086 id = TAILQ_FIRST(&authctxt->keys)) {
1087 TAILQ_REMOVE(&authctxt->keys, id, next);
1091 xfree(id->filename);
1097 userauth_pubkey(Authctxt *authctxt)
1102 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1105 /* move key to the end of the queue */
1106 TAILQ_REMOVE(&authctxt->keys, id, next);
1107 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1109 * send a test message if we have the public key. for
1110 * encrypted keys we cannot do this and have to load the
1111 * private key instead
1113 if (id->key && id->key->type != KEY_RSA1) {
1114 debug("Offering public key: %s", id->filename);
1115 sent = send_pubkey_test(authctxt, id);
1116 } else if (id->key == NULL) {
1117 debug("Trying private key: %s", id->filename);
1118 id->key = load_identity_file(id->filename);
1119 if (id->key != NULL) {
1121 sent = sign_and_send_pubkey(authctxt, id);
1133 * Send userauth request message specifying keyboard-interactive method.
1136 userauth_kbdint(Authctxt *authctxt)
1138 static int attempt = 0;
1140 if (attempt++ >= options.number_of_password_prompts)
1142 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1143 if (attempt > 1 && !authctxt->info_req_seen) {
1144 debug3("userauth_kbdint: disable: no info_req_seen");
1145 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1149 debug2("userauth_kbdint");
1150 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1151 packet_put_cstring(authctxt->server_user);
1152 packet_put_cstring(authctxt->service);
1153 packet_put_cstring(authctxt->method->name);
1154 packet_put_cstring(""); /* lang */
1155 packet_put_cstring(options.kbd_interactive_devices ?
1156 options.kbd_interactive_devices : "");
1159 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1164 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1167 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1169 Authctxt *authctxt = ctxt;
1170 char *name, *inst, *lang, *prompt, *response;
1171 u_int num_prompts, i;
1174 debug2("input_userauth_info_req");
1176 if (authctxt == NULL)
1177 fatal("input_userauth_info_req: no authentication context");
1179 authctxt->info_req_seen = 1;
1181 name = packet_get_string(NULL);
1182 inst = packet_get_string(NULL);
1183 lang = packet_get_string(NULL);
1184 if (strlen(name) > 0)
1186 if (strlen(inst) > 0)
1192 num_prompts = packet_get_int();
1194 * Begin to build info response packet based on prompts requested.
1195 * We commit to providing the correct number of responses, so if
1196 * further on we run into a problem that prevents this, we have to
1197 * be sure and clean this up and send a correct error response.
1199 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1200 packet_put_int(num_prompts);
1202 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1203 for (i = 0; i < num_prompts; i++) {
1204 prompt = packet_get_string(NULL);
1205 echo = packet_get_char();
1207 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1209 packet_put_cstring(response);
1210 memset(response, 0, strlen(response));
1214 packet_check_eom(); /* done with parsing incoming message. */
1216 packet_add_padding(64);
1221 ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1222 u_char *data, u_int datalen)
1227 int to[2], from[2], status, version = 2;
1229 debug2("ssh_keysign called");
1231 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1232 error("ssh_keysign: no installed: %s", strerror(errno));
1235 if (fflush(stdout) != 0)
1236 error("ssh_keysign: fflush: %s", strerror(errno));
1238 error("ssh_keysign: pipe: %s", strerror(errno));
1241 if (pipe(from) < 0) {
1242 error("ssh_keysign: pipe: %s", strerror(errno));
1245 if ((pid = fork()) < 0) {
1246 error("ssh_keysign: fork: %s", strerror(errno));
1253 if (dup2(from[1], STDOUT_FILENO) < 0)
1254 fatal("ssh_keysign: dup2: %s", strerror(errno));
1256 if (dup2(to[0], STDIN_FILENO) < 0)
1257 fatal("ssh_keysign: dup2: %s", strerror(errno));
1260 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1261 fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1268 buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1269 buffer_put_string(&b, data, datalen);
1270 if (ssh_msg_send(to[1], version, &b) == -1)
1271 fatal("ssh_keysign: couldn't send request");
1273 if (ssh_msg_recv(from[0], &b) < 0) {
1274 error("ssh_keysign: no reply");
1281 while (waitpid(pid, &status, 0) < 0)
1285 if (buffer_get_char(&b) != version) {
1286 error("ssh_keysign: bad version");
1290 *sigp = buffer_get_string(&b, lenp);
1297 userauth_hostbased(Authctxt *authctxt)
1299 Key *private = NULL;
1300 Sensitive *sensitive = authctxt->sensitive;
1302 u_char *signature, *blob;
1303 char *chost, *pkalg, *p;
1304 const char *service;
1306 int ok, i, len, found = 0;
1308 /* check for a useful key */
1309 for (i = 0; i < sensitive->nkeys; i++) {
1310 private = sensitive->keys[i];
1311 if (private && private->type != KEY_RSA1) {
1313 /* we take and free the key */
1314 sensitive->keys[i] = NULL;
1319 debug("No more client hostkeys for hostbased authentication.");
1322 if (key_to_blob(private, &blob, &blen) == 0) {
1326 /* figure out a name for the client host */
1327 p = get_local_name(packet_get_connection_in());
1329 error("userauth_hostbased: cannot get local ipaddr/name");
1333 len = strlen(p) + 2;
1334 chost = xmalloc(len);
1335 strlcpy(chost, p, len);
1336 strlcat(chost, ".", len);
1337 debug2("userauth_hostbased: chost %s", chost);
1340 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1342 pkalg = xstrdup(key_ssh_name(private));
1344 /* construct data */
1345 buffer_put_string(&b, session_id2, session_id2_len);
1346 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1347 buffer_put_cstring(&b, authctxt->server_user);
1348 buffer_put_cstring(&b, service);
1349 buffer_put_cstring(&b, authctxt->method->name);
1350 buffer_put_cstring(&b, pkalg);
1351 buffer_put_string(&b, blob, blen);
1352 buffer_put_cstring(&b, chost);
1353 buffer_put_cstring(&b, authctxt->local_user);
1357 if (sensitive->external_keysign)
1358 ok = ssh_keysign(private, &signature, &slen,
1359 buffer_ptr(&b), buffer_len(&b));
1361 ok = key_sign(private, &signature, &slen,
1362 buffer_ptr(&b), buffer_len(&b));
1366 error("key_sign failed");
1371 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1372 packet_put_cstring(authctxt->server_user);
1373 packet_put_cstring(authctxt->service);
1374 packet_put_cstring(authctxt->method->name);
1375 packet_put_cstring(pkalg);
1376 packet_put_string(blob, blen);
1377 packet_put_cstring(chost);
1378 packet_put_cstring(authctxt->local_user);
1379 packet_put_string(signature, slen);
1380 memset(signature, 's', slen);
1389 /* find auth method */
1392 * given auth method name, if configurable options permit this method fill
1393 * in auth_ident field and return true, otherwise return false.
1396 authmethod_is_enabled(Authmethod *method)
1400 /* return false if options indicate this method is disabled */
1401 if (method->enabled == NULL || *method->enabled == 0)
1403 /* return false if batch mode is enabled but method needs interactive mode */
1404 if (method->batch_flag != NULL && *method->batch_flag != 0)
1410 authmethod_lookup(const char *name)
1412 Authmethod *method = NULL;
1414 for (method = authmethods; method->name != NULL; method++)
1415 if (strcmp(name, method->name) == 0)
1417 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1421 /* XXX internal state */
1422 static Authmethod *current = NULL;
1423 static char *supported = NULL;
1424 static char *preferred = NULL;
1427 * Given the authentication method list sent by the server, return the
1428 * next method we should try. If the server initially sends a nil list,
1429 * use a built-in default list.
1432 authmethod_get(char *authlist)
1437 /* Use a suitable default if we're passed a nil list. */
1438 if (authlist == NULL || strlen(authlist) == 0)
1439 authlist = options.preferred_authentications;
1441 if (supported == NULL || strcmp(authlist, supported) != 0) {
1442 debug3("start over, passed a different list %s", authlist);
1443 if (supported != NULL)
1445 supported = xstrdup(authlist);
1446 preferred = options.preferred_authentications;
1447 debug3("preferred %s", preferred);
1449 } else if (current != NULL && authmethod_is_enabled(current))
1453 if ((name = match_list(preferred, supported, &next)) == NULL) {
1454 debug("No more authentication methods to try.");
1459 debug3("authmethod_lookup %s", name);
1460 debug3("remaining preferred: %s", preferred);
1461 if ((current = authmethod_lookup(name)) != NULL &&
1462 authmethod_is_enabled(current)) {
1463 debug3("authmethod_is_enabled %s", name);
1464 debug("Next authentication method: %s", name);
1471 authmethods_get(void)
1473 Authmethod *method = NULL;
1478 for (method = authmethods; method->name != NULL; method++) {
1479 if (authmethod_is_enabled(method)) {
1480 if (buffer_len(&b) > 0)
1481 buffer_append(&b, ",", 1);
1482 buffer_append(&b, method->name, strlen(method->name));
1485 buffer_append(&b, "\0", 1);
1486 list = xstrdup(buffer_ptr(&b));