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.
27 #include <sys/types.h>
31 #include "openbsd-compat/sys-queue.h"
42 #include "myproposal.h"
43 #include "sshconnect.h"
54 #include "pathnames.h"
61 extern char *client_version_string;
62 extern char *server_version_string;
63 extern Options options;
69 u_char *session_id2 = NULL;
70 u_int session_id2_len = 0;
73 struct sockaddr *xxx_hostaddr;
78 verify_host_key_callback(Key *hostkey)
80 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
81 fatal("Host key verification failed.");
86 ssh_kex2(char *host, struct sockaddr *hostaddr)
91 xxx_hostaddr = hostaddr;
93 if (options.ciphers == (char *)-1) {
94 logit("No valid ciphers for protocol version 2 given, using defaults.");
95 options.ciphers = NULL;
97 if (options.ciphers != NULL) {
98 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
99 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
101 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
102 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
103 myproposal[PROPOSAL_ENC_ALGS_STOC] =
104 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
105 if (options.compression) {
106 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
107 myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
109 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
110 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
112 if (options.macs != NULL) {
113 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
114 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
116 if (options.hostkeyalgorithms != NULL)
117 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
118 options.hostkeyalgorithms;
120 if (options.rekey_limit)
121 packet_set_rekey_limit(options.rekey_limit);
123 /* start key exchange */
124 kex = kex_setup(myproposal);
125 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
126 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
127 kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
128 kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
129 kex->client_version_string=client_version_string;
130 kex->server_version_string=server_version_string;
131 kex->verify_host_key=&verify_host_key_callback;
135 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
137 session_id2 = kex->session_id;
138 session_id2_len = kex->session_id_len;
141 /* send 1st encrypted/maced/compressed message */
142 packet_start(SSH2_MSG_IGNORE);
143 packet_put_cstring("markus");
153 typedef struct Authctxt Authctxt;
154 typedef struct Authmethod Authmethod;
155 typedef struct identity Identity;
156 typedef struct idlist Idlist;
159 TAILQ_ENTRY(identity) next;
160 AuthenticationConnection *ac; /* set if agent supports key */
161 Key *key; /* public/private key */
162 char *filename; /* comment for agent-only keys */
164 int isprivate; /* key points to the private key */
166 TAILQ_HEAD(idlist, identity);
169 const char *server_user;
170 const char *local_user;
178 AuthenticationConnection *agent;
180 Sensitive *sensitive;
181 /* kbd-interactive */
187 char *name; /* string to compare against server's list */
188 int (*userauth)(Authctxt *authctxt);
189 int *enabled; /* flag in option struct that enables method */
190 int *batch_flag; /* flag in option struct that disables method */
193 void input_userauth_success(int, u_int32_t, void *);
194 void input_userauth_failure(int, u_int32_t, void *);
195 void input_userauth_banner(int, u_int32_t, void *);
196 void input_userauth_error(int, u_int32_t, void *);
197 void input_userauth_info_req(int, u_int32_t, void *);
198 void input_userauth_pk_ok(int, u_int32_t, void *);
199 void input_userauth_passwd_changereq(int, u_int32_t, void *);
201 int userauth_none(Authctxt *);
202 int userauth_pubkey(Authctxt *);
203 int userauth_passwd(Authctxt *);
204 int userauth_kbdint(Authctxt *);
205 int userauth_hostbased(Authctxt *);
206 int userauth_kerberos(Authctxt *);
209 int userauth_gssapi(Authctxt *authctxt);
210 void input_gssapi_response(int type, u_int32_t, void *);
211 void input_gssapi_token(int type, u_int32_t, void *);
212 void input_gssapi_hash(int type, u_int32_t, void *);
213 void input_gssapi_error(int, u_int32_t, void *);
214 void input_gssapi_errtok(int, u_int32_t, void *);
217 void userauth(Authctxt *, char *);
219 static int sign_and_send_pubkey(Authctxt *, Identity *);
220 static void pubkey_prepare(Authctxt *);
221 static void pubkey_cleanup(Authctxt *);
222 static Key *load_identity_file(char *);
224 static Authmethod *authmethod_get(char *authlist);
225 static Authmethod *authmethod_lookup(const char *name);
226 static char *authmethods_get(void);
228 Authmethod authmethods[] = {
232 &options.gss_authentication,
237 &options.hostbased_authentication,
241 &options.pubkey_authentication,
243 {"keyboard-interactive",
245 &options.kbd_interactive_authentication,
246 &options.batch_mode},
249 &options.password_authentication,
250 &options.batch_mode},
255 {NULL, NULL, NULL, NULL}
259 ssh_userauth2(const char *local_user, const char *server_user, char *host,
260 Sensitive *sensitive)
265 if (options.challenge_response_authentication)
266 options.kbd_interactive_authentication = 1;
268 packet_start(SSH2_MSG_SERVICE_REQUEST);
269 packet_put_cstring("ssh-userauth");
271 debug("SSH2_MSG_SERVICE_REQUEST sent");
273 type = packet_read();
274 if (type != SSH2_MSG_SERVICE_ACCEPT)
275 fatal("Server denied authentication request: %d", type);
276 if (packet_remaining() > 0) {
277 char *reply = packet_get_string(NULL);
278 debug2("service_accept: %s", reply);
281 debug2("buggy server: service_accept w/o service");
284 debug("SSH2_MSG_SERVICE_ACCEPT received");
286 if (options.preferred_authentications == NULL)
287 options.preferred_authentications = authmethods_get();
289 /* setup authentication context */
290 memset(&authctxt, 0, sizeof(authctxt));
291 pubkey_prepare(&authctxt);
292 authctxt.server_user = server_user;
293 authctxt.local_user = local_user;
294 authctxt.host = host;
295 authctxt.service = "ssh-connection"; /* service name */
296 authctxt.success = 0;
297 authctxt.method = authmethod_lookup("none");
298 authctxt.authlist = NULL;
299 authctxt.methoddata = NULL;
300 authctxt.sensitive = sensitive;
301 authctxt.info_req_seen = 0;
302 if (authctxt.method == NULL)
303 fatal("ssh_userauth2: internal error: cannot send userauth none request");
305 /* initial userauth request */
306 userauth_none(&authctxt);
308 dispatch_init(&input_userauth_error);
309 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
310 dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
311 dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
312 dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
314 pubkey_cleanup(&authctxt);
315 dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
317 debug("Authentication succeeded (%s).", authctxt.method->name);
321 userauth(Authctxt *authctxt, char *authlist)
323 if (authctxt->methoddata) {
324 xfree(authctxt->methoddata);
325 authctxt->methoddata = NULL;
327 if (authlist == NULL) {
328 authlist = authctxt->authlist;
330 if (authctxt->authlist)
331 xfree(authctxt->authlist);
332 authctxt->authlist = authlist;
335 Authmethod *method = authmethod_get(authlist);
337 fatal("Permission denied (%s).", authlist);
338 authctxt->method = method;
340 /* reset the per method handler */
341 dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
342 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
344 /* and try new method */
345 if (method->userauth(authctxt) != 0) {
346 debug2("we sent a %s packet, wait for reply", method->name);
349 debug2("we did not send a packet, disable method");
350 method->enabled = NULL;
356 input_userauth_error(int type, u_int32_t seq, void *ctxt)
358 fatal("input_userauth_error: bad message during authentication: "
363 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
367 debug3("input_userauth_banner");
368 msg = packet_get_string(NULL);
369 lang = packet_get_string(NULL);
370 if (options.log_level > SYSLOG_LEVEL_QUIET)
371 fprintf(stderr, "%s", msg);
377 input_userauth_success(int type, u_int32_t seq, void *ctxt)
379 Authctxt *authctxt = ctxt;
380 if (authctxt == NULL)
381 fatal("input_userauth_success: no authentication context");
382 if (authctxt->authlist) {
383 xfree(authctxt->authlist);
384 authctxt->authlist = NULL;
386 if (authctxt->methoddata) {
387 xfree(authctxt->methoddata);
388 authctxt->methoddata = NULL;
390 authctxt->success = 1; /* break out */
394 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
396 Authctxt *authctxt = ctxt;
397 char *authlist = NULL;
400 if (authctxt == NULL)
401 fatal("input_userauth_failure: no authentication context");
403 authlist = packet_get_string(NULL);
404 partial = packet_get_char();
408 logit("Authenticated with partial success.");
409 debug("Authentications that can continue: %s", authlist);
411 userauth(authctxt, authlist);
414 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
416 Authctxt *authctxt = ctxt;
420 int pktype, sent = 0;
425 if (authctxt == NULL)
426 fatal("input_userauth_pk_ok: no authentication context");
427 if (datafellows & SSH_BUG_PKOK) {
428 /* this is similar to SSH_BUG_PKAUTH */
429 debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
430 pkblob = packet_get_string(&blen);
432 buffer_append(&b, pkblob, blen);
433 pkalg = buffer_get_string(&b, &alen);
436 pkalg = packet_get_string(&alen);
437 pkblob = packet_get_string(&blen);
441 debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
443 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
444 debug("unknown pkalg %s", pkalg);
447 if ((key = key_from_blob(pkblob, blen)) == NULL) {
448 debug("no key from blob. pkalg %s", pkalg);
451 if (key->type != pktype) {
452 error("input_userauth_pk_ok: type mismatch "
453 "for decoded key (received %d, expected %d)",
457 fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
458 debug2("input_userauth_pk_ok: fp %s", fp);
462 * search keys in the reverse order, because last candidate has been
463 * moved to the end of the queue. this also avoids confusion by
466 TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
467 if (key_equal(key, id->key)) {
468 sent = sign_and_send_pubkey(authctxt, id);
478 /* try another method if we did not send a packet */
480 userauth(authctxt, NULL);
485 userauth_gssapi(Authctxt *authctxt)
487 Gssctxt *gssctxt = NULL;
488 static gss_OID_set gss_supported = NULL;
489 static u_int mech = 0;
493 /* Try one GSSAPI method at a time, rather than sending them all at
496 if (gss_supported == NULL)
497 gss_indicate_mechs(&min, &gss_supported);
499 /* Check to see if the mechanism is usable before we offer it */
500 while (mech < gss_supported->count && !ok) {
502 ssh_gssapi_delete_ctx(&gssctxt);
503 ssh_gssapi_build_ctx(&gssctxt);
504 ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]);
506 /* My DER encoding requires length<128 */
507 if (gss_supported->elements[mech].length < 128 &&
508 !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
510 ok = 1; /* Mechanism works */
517 ssh_gssapi_delete_ctx(&gssctxt);
521 authctxt->methoddata=(void *)gssctxt;
523 packet_start(SSH2_MSG_USERAUTH_REQUEST);
524 packet_put_cstring(authctxt->server_user);
525 packet_put_cstring(authctxt->service);
526 packet_put_cstring(authctxt->method->name);
530 packet_put_int((gss_supported->elements[mech].length) + 2);
531 packet_put_char(SSH_GSS_OIDTYPE);
532 packet_put_char(gss_supported->elements[mech].length);
533 packet_put_raw(gss_supported->elements[mech].elements,
534 gss_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 process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
551 Authctxt *authctxt = ctxt;
552 Gssctxt *gssctxt = authctxt->methoddata;
553 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
554 gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
555 gss_buffer_desc gssbuf;
556 OM_uint32 status, ms, flags;
559 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
560 recv_tok, &send_tok, &flags);
562 if (send_tok.length > 0) {
563 if (GSS_ERROR(status))
564 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
566 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
568 packet_put_string(send_tok.value, send_tok.length);
570 gss_release_buffer(&ms, &send_tok);
573 if (status == GSS_S_COMPLETE) {
574 /* send either complete or MIC, depending on mechanism */
575 if (!(flags & GSS_C_INTEG_FLAG)) {
576 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
579 ssh_gssapi_buildmic(&b, authctxt->server_user,
580 authctxt->service, "gssapi-with-mic");
582 gssbuf.value = buffer_ptr(&b);
583 gssbuf.length = buffer_len(&b);
585 status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
587 if (!GSS_ERROR(status)) {
588 packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
589 packet_put_string(mic.value, mic.length);
595 gss_release_buffer(&ms, &mic);
603 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
605 Authctxt *authctxt = ctxt;
610 if (authctxt == NULL)
611 fatal("input_gssapi_response: no authentication context");
612 gssctxt = authctxt->methoddata;
615 oidv = packet_get_string(&oidlen);
618 oidv[0] != SSH_GSS_OIDTYPE ||
619 oidv[1] != oidlen - 2) {
621 debug("Badly encoded mechanism OID received");
622 userauth(authctxt, NULL);
626 if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
627 fatal("Server returned different OID than expected");
633 if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
634 /* Start again with next method on list */
635 debug("Trying to start again");
636 userauth(authctxt, NULL);
642 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
644 Authctxt *authctxt = ctxt;
645 gss_buffer_desc recv_tok;
649 if (authctxt == NULL)
650 fatal("input_gssapi_response: no authentication context");
652 recv_tok.value = packet_get_string(&slen);
653 recv_tok.length = slen; /* safe typecast */
657 status = process_gssapi_token(ctxt, &recv_tok);
659 xfree(recv_tok.value);
661 if (GSS_ERROR(status)) {
662 /* Start again with the next method in the list */
663 userauth(authctxt, NULL);
669 input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
671 Authctxt *authctxt = ctxt;
673 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
674 gss_buffer_desc recv_tok;
675 OM_uint32 status, ms;
678 if (authctxt == NULL)
679 fatal("input_gssapi_response: no authentication context");
680 gssctxt = authctxt->methoddata;
682 recv_tok.value = packet_get_string(&len);
683 recv_tok.length = len;
687 /* Stick it into GSSAPI and see what it says */
688 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
689 &recv_tok, &send_tok, NULL);
691 xfree(recv_tok.value);
692 gss_release_buffer(&ms, &send_tok);
694 /* Server will be returning a failed packet after this one */
698 input_gssapi_error(int type, u_int32_t plen, void *ctxt)
704 maj=packet_get_int();
705 min=packet_get_int();
706 msg=packet_get_string(NULL);
707 lang=packet_get_string(NULL);
711 debug("Server GSSAPI Error:\n%s", msg);
718 userauth_none(Authctxt *authctxt)
720 /* initial userauth request */
721 packet_start(SSH2_MSG_USERAUTH_REQUEST);
722 packet_put_cstring(authctxt->server_user);
723 packet_put_cstring(authctxt->service);
724 packet_put_cstring(authctxt->method->name);
730 userauth_passwd(Authctxt *authctxt)
732 static int attempt = 0;
736 if (attempt++ >= options.number_of_password_prompts)
740 error("Permission denied, please try again.");
742 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
743 authctxt->server_user, authctxt->host);
744 password = read_passphrase(prompt, 0);
745 packet_start(SSH2_MSG_USERAUTH_REQUEST);
746 packet_put_cstring(authctxt->server_user);
747 packet_put_cstring(authctxt->service);
748 packet_put_cstring(authctxt->method->name);
750 packet_put_cstring(password);
751 memset(password, 0, strlen(password));
753 packet_add_padding(64);
756 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
757 &input_userauth_passwd_changereq);
762 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
765 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
767 Authctxt *authctxt = ctxt;
768 char *info, *lang, *password = NULL, *retype = NULL;
771 debug2("input_userauth_passwd_changereq");
773 if (authctxt == NULL)
774 fatal("input_userauth_passwd_changereq: "
775 "no authentication context");
777 info = packet_get_string(NULL);
778 lang = packet_get_string(NULL);
779 if (strlen(info) > 0)
783 packet_start(SSH2_MSG_USERAUTH_REQUEST);
784 packet_put_cstring(authctxt->server_user);
785 packet_put_cstring(authctxt->service);
786 packet_put_cstring(authctxt->method->name);
787 packet_put_char(1); /* additional info */
788 snprintf(prompt, sizeof(prompt),
789 "Enter %.30s@%.128s's old password: ",
790 authctxt->server_user, authctxt->host);
791 password = read_passphrase(prompt, 0);
792 packet_put_cstring(password);
793 memset(password, 0, strlen(password));
796 while (password == NULL) {
797 snprintf(prompt, sizeof(prompt),
798 "Enter %.30s@%.128s's new password: ",
799 authctxt->server_user, authctxt->host);
800 password = read_passphrase(prompt, RP_ALLOW_EOF);
801 if (password == NULL) {
805 snprintf(prompt, sizeof(prompt),
806 "Retype %.30s@%.128s's new password: ",
807 authctxt->server_user, authctxt->host);
808 retype = read_passphrase(prompt, 0);
809 if (strcmp(password, retype) != 0) {
810 memset(password, 0, strlen(password));
812 logit("Mismatch; try again, EOF to quit.");
815 memset(retype, 0, strlen(retype));
818 packet_put_cstring(password);
819 memset(password, 0, strlen(password));
821 packet_add_padding(64);
824 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
825 &input_userauth_passwd_changereq);
829 identity_sign(Identity *id, u_char **sigp, u_int *lenp,
830 u_char *data, u_int datalen)
835 /* the agent supports this key */
837 return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
840 * we have already loaded the private key or
841 * the private key is stored in external hardware
843 if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
844 return (key_sign(id->key, sigp, lenp, data, datalen));
845 /* load the private key from the file */
846 if ((prv = load_identity_file(id->filename)) == NULL)
848 ret = key_sign(prv, sigp, lenp, data, datalen);
854 sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
857 u_char *blob, *signature;
863 debug3("sign_and_send_pubkey");
865 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
866 /* we cannot handle this key */
867 debug3("sign_and_send_pubkey: cannot handle key");
870 /* data to be signed */
872 if (datafellows & SSH_OLD_SESSIONID) {
873 buffer_append(&b, session_id2, session_id2_len);
874 skip = session_id2_len;
876 buffer_put_string(&b, session_id2, session_id2_len);
877 skip = buffer_len(&b);
879 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
880 buffer_put_cstring(&b, authctxt->server_user);
881 buffer_put_cstring(&b,
882 datafellows & SSH_BUG_PKSERVICE ?
885 if (datafellows & SSH_BUG_PKAUTH) {
886 buffer_put_char(&b, have_sig);
888 buffer_put_cstring(&b, authctxt->method->name);
889 buffer_put_char(&b, have_sig);
890 buffer_put_cstring(&b, key_ssh_name(id->key));
892 buffer_put_string(&b, blob, bloblen);
894 /* generate signature */
895 ret = identity_sign(id, &signature, &slen,
896 buffer_ptr(&b), buffer_len(&b));
905 if (datafellows & SSH_BUG_PKSERVICE) {
907 buffer_append(&b, session_id2, session_id2_len);
908 skip = session_id2_len;
909 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
910 buffer_put_cstring(&b, authctxt->server_user);
911 buffer_put_cstring(&b, authctxt->service);
912 buffer_put_cstring(&b, authctxt->method->name);
913 buffer_put_char(&b, have_sig);
914 if (!(datafellows & SSH_BUG_PKAUTH))
915 buffer_put_cstring(&b, key_ssh_name(id->key));
916 buffer_put_string(&b, blob, bloblen);
920 /* append signature */
921 buffer_put_string(&b, signature, slen);
924 /* skip session id and packet type */
925 if (buffer_len(&b) < skip + 1)
926 fatal("userauth_pubkey: internal error");
927 buffer_consume(&b, skip + 1);
929 /* put remaining data from buffer into packet */
930 packet_start(SSH2_MSG_USERAUTH_REQUEST);
931 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
939 send_pubkey_test(Authctxt *authctxt, Identity *id)
942 u_int bloblen, have_sig = 0;
944 debug3("send_pubkey_test");
946 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
947 /* we cannot handle this key */
948 debug3("send_pubkey_test: cannot handle key");
951 /* register callback for USERAUTH_PK_OK message */
952 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
954 packet_start(SSH2_MSG_USERAUTH_REQUEST);
955 packet_put_cstring(authctxt->server_user);
956 packet_put_cstring(authctxt->service);
957 packet_put_cstring(authctxt->method->name);
958 packet_put_char(have_sig);
959 if (!(datafellows & SSH_BUG_PKAUTH))
960 packet_put_cstring(key_ssh_name(id->key));
961 packet_put_string(blob, bloblen);
968 load_identity_file(char *filename)
971 char prompt[300], *passphrase;
975 if (stat(filename, &st) < 0) {
976 debug3("no such identity: %s", filename);
979 private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
980 if (private == NULL) {
981 if (options.batch_mode)
983 snprintf(prompt, sizeof prompt,
984 "Enter passphrase for key '%.100s': ", filename);
985 for (i = 0; i < options.number_of_password_prompts; i++) {
986 passphrase = read_passphrase(prompt, 0);
987 if (strcmp(passphrase, "") != 0) {
988 private = key_load_private_type(KEY_UNSPEC, filename,
992 debug2("no passphrase given, try next key");
995 memset(passphrase, 0, strlen(passphrase));
997 if (private != NULL || quit)
999 debug2("bad passphrase given, try again...");
1006 * try keys in the following order:
1007 * 1. agent keys that are found in the config file
1008 * 2. other agent keys
1009 * 3. keys that are only listed in the config file
1012 pubkey_prepare(Authctxt *authctxt)
1015 Idlist agent, files, *preferred;
1017 AuthenticationConnection *ac;
1021 TAILQ_INIT(&agent); /* keys from the agent */
1022 TAILQ_INIT(&files); /* keys from the config file */
1023 preferred = &authctxt->keys;
1024 TAILQ_INIT(preferred); /* preferred order of keys */
1026 /* list of keys stored in the filesystem */
1027 for (i = 0; i < options.num_identity_files; i++) {
1028 key = options.identity_keys[i];
1029 if (key && key->type == KEY_RSA1)
1031 options.identity_keys[i] = NULL;
1032 id = xcalloc(1, sizeof(*id));
1034 id->filename = xstrdup(options.identity_files[i]);
1035 TAILQ_INSERT_TAIL(&files, id, next);
1037 /* list of keys supported by the agent */
1038 if ((ac = ssh_get_authentication_connection())) {
1039 for (key = ssh_get_first_identity(ac, &comment, 2);
1041 key = ssh_get_next_identity(ac, &comment, 2)) {
1043 TAILQ_FOREACH(id, &files, next) {
1044 /* agent keys from the config file are preferred */
1045 if (key_equal(key, id->key)) {
1048 TAILQ_REMOVE(&files, id, next);
1049 TAILQ_INSERT_TAIL(preferred, id, next);
1055 if (!found && !options.identities_only) {
1056 id = xcalloc(1, sizeof(*id));
1058 id->filename = comment;
1060 TAILQ_INSERT_TAIL(&agent, id, next);
1063 /* append remaining agent keys */
1064 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1065 TAILQ_REMOVE(&agent, id, next);
1066 TAILQ_INSERT_TAIL(preferred, id, next);
1068 authctxt->agent = ac;
1070 /* append remaining keys from the config file */
1071 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1072 TAILQ_REMOVE(&files, id, next);
1073 TAILQ_INSERT_TAIL(preferred, id, next);
1075 TAILQ_FOREACH(id, preferred, next) {
1076 debug2("key: %s (%p)", id->filename, id->key);
1081 pubkey_cleanup(Authctxt *authctxt)
1085 if (authctxt->agent != NULL)
1086 ssh_close_authentication_connection(authctxt->agent);
1087 for (id = TAILQ_FIRST(&authctxt->keys); id;
1088 id = TAILQ_FIRST(&authctxt->keys)) {
1089 TAILQ_REMOVE(&authctxt->keys, id, next);
1093 xfree(id->filename);
1099 userauth_pubkey(Authctxt *authctxt)
1104 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1107 /* move key to the end of the queue */
1108 TAILQ_REMOVE(&authctxt->keys, id, next);
1109 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1111 * send a test message if we have the public key. for
1112 * encrypted keys we cannot do this and have to load the
1113 * private key instead
1115 if (id->key && id->key->type != KEY_RSA1) {
1116 debug("Offering public key: %s", id->filename);
1117 sent = send_pubkey_test(authctxt, id);
1118 } else if (id->key == NULL) {
1119 debug("Trying private key: %s", id->filename);
1120 id->key = load_identity_file(id->filename);
1121 if (id->key != NULL) {
1123 sent = sign_and_send_pubkey(authctxt, id);
1135 * Send userauth request message specifying keyboard-interactive method.
1138 userauth_kbdint(Authctxt *authctxt)
1140 static int attempt = 0;
1142 if (attempt++ >= options.number_of_password_prompts)
1144 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1145 if (attempt > 1 && !authctxt->info_req_seen) {
1146 debug3("userauth_kbdint: disable: no info_req_seen");
1147 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1151 debug2("userauth_kbdint");
1152 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1153 packet_put_cstring(authctxt->server_user);
1154 packet_put_cstring(authctxt->service);
1155 packet_put_cstring(authctxt->method->name);
1156 packet_put_cstring(""); /* lang */
1157 packet_put_cstring(options.kbd_interactive_devices ?
1158 options.kbd_interactive_devices : "");
1161 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1166 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1169 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1171 Authctxt *authctxt = ctxt;
1172 char *name, *inst, *lang, *prompt, *response;
1173 u_int num_prompts, i;
1176 debug2("input_userauth_info_req");
1178 if (authctxt == NULL)
1179 fatal("input_userauth_info_req: no authentication context");
1181 authctxt->info_req_seen = 1;
1183 name = packet_get_string(NULL);
1184 inst = packet_get_string(NULL);
1185 lang = packet_get_string(NULL);
1186 if (strlen(name) > 0)
1188 if (strlen(inst) > 0)
1194 num_prompts = packet_get_int();
1196 * Begin to build info response packet based on prompts requested.
1197 * We commit to providing the correct number of responses, so if
1198 * further on we run into a problem that prevents this, we have to
1199 * be sure and clean this up and send a correct error response.
1201 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1202 packet_put_int(num_prompts);
1204 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1205 for (i = 0; i < num_prompts; i++) {
1206 prompt = packet_get_string(NULL);
1207 echo = packet_get_char();
1209 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1211 packet_put_cstring(response);
1212 memset(response, 0, strlen(response));
1216 packet_check_eom(); /* done with parsing incoming message. */
1218 packet_add_padding(64);
1223 ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1224 u_char *data, u_int datalen)
1229 int to[2], from[2], status, version = 2;
1231 debug2("ssh_keysign called");
1233 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1234 error("ssh_keysign: no installed: %s", strerror(errno));
1237 if (fflush(stdout) != 0)
1238 error("ssh_keysign: fflush: %s", strerror(errno));
1240 error("ssh_keysign: pipe: %s", strerror(errno));
1243 if (pipe(from) < 0) {
1244 error("ssh_keysign: pipe: %s", strerror(errno));
1247 if ((pid = fork()) < 0) {
1248 error("ssh_keysign: fork: %s", strerror(errno));
1255 if (dup2(from[1], STDOUT_FILENO) < 0)
1256 fatal("ssh_keysign: dup2: %s", strerror(errno));
1258 if (dup2(to[0], STDIN_FILENO) < 0)
1259 fatal("ssh_keysign: dup2: %s", strerror(errno));
1262 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1263 fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1270 buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1271 buffer_put_string(&b, data, datalen);
1272 if (ssh_msg_send(to[1], version, &b) == -1)
1273 fatal("ssh_keysign: couldn't send request");
1275 if (ssh_msg_recv(from[0], &b) < 0) {
1276 error("ssh_keysign: no reply");
1283 while (waitpid(pid, &status, 0) < 0)
1287 if (buffer_get_char(&b) != version) {
1288 error("ssh_keysign: bad version");
1292 *sigp = buffer_get_string(&b, lenp);
1299 userauth_hostbased(Authctxt *authctxt)
1301 Key *private = NULL;
1302 Sensitive *sensitive = authctxt->sensitive;
1304 u_char *signature, *blob;
1305 char *chost, *pkalg, *p;
1306 const char *service;
1308 int ok, i, len, found = 0;
1310 /* check for a useful key */
1311 for (i = 0; i < sensitive->nkeys; i++) {
1312 private = sensitive->keys[i];
1313 if (private && private->type != KEY_RSA1) {
1315 /* we take and free the key */
1316 sensitive->keys[i] = NULL;
1321 debug("No more client hostkeys for hostbased authentication.");
1324 if (key_to_blob(private, &blob, &blen) == 0) {
1328 /* figure out a name for the client host */
1329 p = get_local_name(packet_get_connection_in());
1331 error("userauth_hostbased: cannot get local ipaddr/name");
1336 len = strlen(p) + 2;
1337 xasprintf(&chost, "%s.", p);
1338 debug2("userauth_hostbased: chost %s", chost);
1341 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1343 pkalg = xstrdup(key_ssh_name(private));
1345 /* construct data */
1346 buffer_put_string(&b, session_id2, session_id2_len);
1347 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1348 buffer_put_cstring(&b, authctxt->server_user);
1349 buffer_put_cstring(&b, service);
1350 buffer_put_cstring(&b, authctxt->method->name);
1351 buffer_put_cstring(&b, pkalg);
1352 buffer_put_string(&b, blob, blen);
1353 buffer_put_cstring(&b, chost);
1354 buffer_put_cstring(&b, authctxt->local_user);
1358 if (sensitive->external_keysign)
1359 ok = ssh_keysign(private, &signature, &slen,
1360 buffer_ptr(&b), buffer_len(&b));
1362 ok = key_sign(private, &signature, &slen,
1363 buffer_ptr(&b), buffer_len(&b));
1367 error("key_sign failed");
1373 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1374 packet_put_cstring(authctxt->server_user);
1375 packet_put_cstring(authctxt->service);
1376 packet_put_cstring(authctxt->method->name);
1377 packet_put_cstring(pkalg);
1378 packet_put_string(blob, blen);
1379 packet_put_cstring(chost);
1380 packet_put_cstring(authctxt->local_user);
1381 packet_put_string(signature, slen);
1382 memset(signature, 's', slen);
1392 /* find auth method */
1395 * given auth method name, if configurable options permit this method fill
1396 * in auth_ident field and return true, otherwise return false.
1399 authmethod_is_enabled(Authmethod *method)
1403 /* return false if options indicate this method is disabled */
1404 if (method->enabled == NULL || *method->enabled == 0)
1406 /* return false if batch mode is enabled but method needs interactive mode */
1407 if (method->batch_flag != NULL && *method->batch_flag != 0)
1413 authmethod_lookup(const char *name)
1415 Authmethod *method = NULL;
1417 for (method = authmethods; method->name != NULL; method++)
1418 if (strcmp(name, method->name) == 0)
1420 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1424 /* XXX internal state */
1425 static Authmethod *current = NULL;
1426 static char *supported = NULL;
1427 static char *preferred = NULL;
1430 * Given the authentication method list sent by the server, return the
1431 * next method we should try. If the server initially sends a nil list,
1432 * use a built-in default list.
1435 authmethod_get(char *authlist)
1440 /* Use a suitable default if we're passed a nil list. */
1441 if (authlist == NULL || strlen(authlist) == 0)
1442 authlist = options.preferred_authentications;
1444 if (supported == NULL || strcmp(authlist, supported) != 0) {
1445 debug3("start over, passed a different list %s", authlist);
1446 if (supported != NULL)
1448 supported = xstrdup(authlist);
1449 preferred = options.preferred_authentications;
1450 debug3("preferred %s", preferred);
1452 } else if (current != NULL && authmethod_is_enabled(current))
1456 if ((name = match_list(preferred, supported, &next)) == NULL) {
1457 debug("No more authentication methods to try.");
1462 debug3("authmethod_lookup %s", name);
1463 debug3("remaining preferred: %s", preferred);
1464 if ((current = authmethod_lookup(name)) != NULL &&
1465 authmethod_is_enabled(current)) {
1466 debug3("authmethod_is_enabled %s", name);
1467 debug("Next authentication method: %s", name);
1474 authmethods_get(void)
1476 Authmethod *method = NULL;
1481 for (method = authmethods; method->name != NULL; method++) {
1482 if (authmethod_is_enabled(method)) {
1483 if (buffer_len(&b) > 0)
1484 buffer_append(&b, ",", 1);
1485 buffer_append(&b, method->name, strlen(method->name));
1488 buffer_append(&b, "\0", 1);
1489 list = xstrdup(buffer_ptr(&b));