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utilities - Temporary map out libevtr, ktrdump, and evtranalyze from x86_64
[dragonfly.git] / crypto / openssh / sshconnect2.c
blobc4d566eedca777de3c3d5e20bb6828bdb18d9550
1 /* $OpenBSD: sshconnect2.c,v 1.171 2009/03/05 07:18:19 djm Exp $ */
2 /*
3 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 * Copyright (c) 2008 Damien Miller. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include "includes.h"
28
29 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <sys/wait.h>
32 #include <sys/stat.h>
33
34 #include <errno.h>
35 #include <netdb.h>
36 #include <pwd.h>
37 #include <signal.h>
38 #include <stdarg.h>
39 #include <stdio.h>
40 #include <string.h>
41 #include <unistd.h>
42 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H)
43 #include <vis.h>
44 #endif
45
46 #include "openbsd-compat/sys-queue.h"
47
48 #include "xmalloc.h"
49 #include "ssh.h"
50 #include "ssh2.h"
51 #include "buffer.h"
52 #include "packet.h"
53 #include "compat.h"
54 #include "cipher.h"
55 #include "key.h"
56 #include "kex.h"
57 #include "myproposal.h"
58 #include "sshconnect.h"
59 #include "authfile.h"
60 #include "dh.h"
61 #include "authfd.h"
62 #include "log.h"
63 #include "readconf.h"
64 #include "misc.h"
65 #include "match.h"
66 #include "dispatch.h"
67 #include "canohost.h"
68 #include "msg.h"
69 #include "pathnames.h"
70 #include "uidswap.h"
71 #include "schnorr.h"
72 #include "jpake.h"
73
74 #ifdef GSSAPI
75 #include "ssh-gss.h"
76 #endif
77
78 /* import */
79 extern char *client_version_string;
80 extern char *server_version_string;
81 extern Options options;
82 extern Kex *xxx_kex;
83
84 /* tty_flag is set in ssh.c. use this in ssh_userauth2 */
85 /* if it is set then prevent the switch to the null cipher */
86
87 extern int tty_flag;
88
89 /*
90 * SSH2 key exchange
91 */
92
93 u_char *session_id2 = NULL;
94 u_int session_id2_len = 0;
95
96 char *xxx_host;
97 struct sockaddr *xxx_hostaddr;
98
99 Kex *xxx_kex = NULL;
100
101 static int
102 verify_host_key_callback(Key *hostkey)
103 {
104 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
105 fatal("Host key verification failed.");
106 return 0;
107 }
108
109 void
110 ssh_kex2(char *host, struct sockaddr *hostaddr)
111 {
112 Kex *kex;
113
114 xxx_host = host;
115 xxx_hostaddr = hostaddr;
116
117 if (options.ciphers == (char *)-1) {
118 logit("No valid ciphers for protocol version 2 given, using defaults.");
119 options.ciphers = NULL;
120 }
121 if (options.ciphers != NULL) {
122 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
123 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
124 }
125 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
126 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
127 myproposal[PROPOSAL_ENC_ALGS_STOC] =
128 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
129 if (options.compression) {
130 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
131 myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
132 } else {
133 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
134 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
135 }
136 if (options.macs != NULL) {
137 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
138 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
139 }
140 if (options.hostkeyalgorithms != NULL)
141 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
142 options.hostkeyalgorithms;
143
144 if (options.rekey_limit)
145 packet_set_rekey_limit((u_int32_t)options.rekey_limit);
146
147 /* start key exchange */
148 kex = kex_setup(myproposal);
149 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
150 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
151 kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
152 kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
153 kex->client_version_string=client_version_string;
154 kex->server_version_string=server_version_string;
155 kex->verify_host_key=&verify_host_key_callback;
156
157 xxx_kex = kex;
158
159 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
160
161 session_id2 = kex->session_id;
162 session_id2_len = kex->session_id_len;
163
164 #ifdef DEBUG_KEXDH
165 /* send 1st encrypted/maced/compressed message */
166 packet_start(SSH2_MSG_IGNORE);
167 packet_put_cstring("markus");
168 packet_send();
169 packet_write_wait();
170 #endif
171 }
172
173 /*
174 * Authenticate user
175 */
176
177 typedef struct Authctxt Authctxt;
178 typedef struct Authmethod Authmethod;
179 typedef struct identity Identity;
180 typedef struct idlist Idlist;
181
182 struct identity {
183 TAILQ_ENTRY(identity) next;
184 AuthenticationConnection *ac; /* set if agent supports key */
185 Key *key; /* public/private key */
186 char *filename; /* comment for agent-only keys */
187 int tried;
188 int isprivate; /* key points to the private key */
189 };
190 TAILQ_HEAD(idlist, identity);
191
192 struct Authctxt {
193 const char *server_user;
194 const char *local_user;
195 const char *host;
196 const char *service;
197 Authmethod *method;
198 int success;
199 char *authlist;
200 /* pubkey */
201 Idlist keys;
202 AuthenticationConnection *agent;
203 /* hostbased */
204 Sensitive *sensitive;
205 /* kbd-interactive */
206 int info_req_seen;
207 /* generic */
208 void *methoddata;
209 };
210 struct Authmethod {
211 char *name; /* string to compare against server's list */
212 int (*userauth)(Authctxt *authctxt);
213 void (*cleanup)(Authctxt *authctxt);
214 int *enabled; /* flag in option struct that enables method */
215 int *batch_flag; /* flag in option struct that disables method */
216 };
217
218 void input_userauth_success(int, u_int32_t, void *);
219 void input_userauth_failure(int, u_int32_t, void *);
220 void input_userauth_banner(int, u_int32_t, void *);
221 void input_userauth_error(int, u_int32_t, void *);
222 void input_userauth_info_req(int, u_int32_t, void *);
223 void input_userauth_pk_ok(int, u_int32_t, void *);
224 void input_userauth_passwd_changereq(int, u_int32_t, void *);
225 void input_userauth_jpake_server_step1(int, u_int32_t, void *);
226 void input_userauth_jpake_server_step2(int, u_int32_t, void *);
227 void input_userauth_jpake_server_confirm(int, u_int32_t, void *);
228
229 int userauth_none(Authctxt *);
230 int userauth_pubkey(Authctxt *);
231 int userauth_passwd(Authctxt *);
232 int userauth_kbdint(Authctxt *);
233 int userauth_hostbased(Authctxt *);
234 int userauth_jpake(Authctxt *);
235
236 void userauth_jpake_cleanup(Authctxt *);
237
238 #ifdef GSSAPI
239 int userauth_gssapi(Authctxt *authctxt);
240 void input_gssapi_response(int type, u_int32_t, void *);
241 void input_gssapi_token(int type, u_int32_t, void *);
242 void input_gssapi_hash(int type, u_int32_t, void *);
243 void input_gssapi_error(int, u_int32_t, void *);
244 void input_gssapi_errtok(int, u_int32_t, void *);
245 #endif
246
247 void userauth(Authctxt *, char *);
248
249 static int sign_and_send_pubkey(Authctxt *, Identity *);
250 static void pubkey_prepare(Authctxt *);
251 static void pubkey_cleanup(Authctxt *);
252 static Key *load_identity_file(char *);
253
254 static Authmethod *authmethod_get(char *authlist);
255 static Authmethod *authmethod_lookup(const char *name);
256 static char *authmethods_get(void);
257
258 Authmethod authmethods[] = {
259 #ifdef GSSAPI
260 {"gssapi-with-mic",
261 userauth_gssapi,
262 NULL,
263 &options.gss_authentication,
264 NULL},
265 #endif
266 {"hostbased",
267 userauth_hostbased,
268 NULL,
269 &options.hostbased_authentication,
270 NULL},
271 {"publickey",
272 userauth_pubkey,
273 NULL,
274 &options.pubkey_authentication,
275 NULL},
276 #ifdef JPAKE
277 {"jpake-01@openssh.com",
278 userauth_jpake,
279 userauth_jpake_cleanup,
280 &options.zero_knowledge_password_authentication,
281 &options.batch_mode},
282 #endif
283 {"keyboard-interactive",
284 userauth_kbdint,
285 NULL,
286 &options.kbd_interactive_authentication,
287 &options.batch_mode},
288 {"password",
289 userauth_passwd,
290 NULL,
291 &options.password_authentication,
292 &options.batch_mode},
293 {"none",
294 userauth_none,
295 NULL,
296 NULL,
297 NULL},
298 {NULL, NULL, NULL, NULL, NULL}
299 };
300
301 void
302 ssh_userauth2(const char *local_user, const char *server_user, char *host,
303 Sensitive *sensitive)
304 {
305 Authctxt authctxt;
306 int type;
307
308 if (options.challenge_response_authentication)
309 options.kbd_interactive_authentication = 1;
310
311 packet_start(SSH2_MSG_SERVICE_REQUEST);
312 packet_put_cstring("ssh-userauth");
313 packet_send();
314 debug("SSH2_MSG_SERVICE_REQUEST sent");
315 packet_write_wait();
316 type = packet_read();
317 if (type != SSH2_MSG_SERVICE_ACCEPT)
318 fatal("Server denied authentication request: %d", type);
319 if (packet_remaining() > 0) {
320 char *reply = packet_get_string(NULL);
321 debug2("service_accept: %s", reply);
322 xfree(reply);
323 } else {
324 debug2("buggy server: service_accept w/o service");
325 }
326 packet_check_eom();
327 debug("SSH2_MSG_SERVICE_ACCEPT received");
328
329 if (options.preferred_authentications == NULL)
330 options.preferred_authentications = authmethods_get();
331
332 /* setup authentication context */
333 memset(&authctxt, 0, sizeof(authctxt));
334 pubkey_prepare(&authctxt);
335 authctxt.server_user = server_user;
336 authctxt.local_user = local_user;
337 authctxt.host = host;
338 authctxt.service = "ssh-connection"; /* service name */
339 authctxt.success = 0;
340 authctxt.method = authmethod_lookup("none");
341 authctxt.authlist = NULL;
342 authctxt.methoddata = NULL;
343 authctxt.sensitive = sensitive;
344 authctxt.info_req_seen = 0;
345 if (authctxt.method == NULL)
346 fatal("ssh_userauth2: internal error: cannot send userauth none request");
347
348 /* initial userauth request */
349 userauth_none(&authctxt);
350
351 dispatch_init(&input_userauth_error);
352 dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
353 dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
354 dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
355 dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
356
357 pubkey_cleanup(&authctxt);
358 dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
359
360 /* if the user wants to use the none cipher do it */
361 /* post authentication and only if the right conditions are met */
362 /* both of the NONE commands must be true and there must be no */
363 /* tty allocated */
364 if ((options.none_switch == 1) && (options.none_enabled == 1))
365 {
366 if (!tty_flag) /* no null on tty sessions */
367 {
368 debug("Requesting none rekeying...");
369 myproposal[PROPOSAL_ENC_ALGS_STOC] = "none";
370 myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none";
371 kex_prop2buf(&xxx_kex->my,myproposal);
372 packet_request_rekeying();
373 fprintf(stderr, "WARNING: ENABLED NONE CIPHER\n");
374 }
375 else
376 {
377 /* requested NONE cipher when in a tty */
378 debug("Cannot switch to NONE cipher with tty allocated");
379 fprintf(stderr, "NONE cipher switch disabled when a TTY is allocated\n");
380 }
381 }
382 debug("Authentication succeeded (%s).", authctxt.method->name);
383 }
384
385 void
386 userauth(Authctxt *authctxt, char *authlist)
387 {
388 if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
389 authctxt->method->cleanup(authctxt);
390
391 if (authctxt->methoddata) {
392 xfree(authctxt->methoddata);
393 authctxt->methoddata = NULL;
394 }
395 if (authlist == NULL) {
396 authlist = authctxt->authlist;
397 } else {
398 if (authctxt->authlist)
399 xfree(authctxt->authlist);
400 authctxt->authlist = authlist;
401 }
402 for (;;) {
403 Authmethod *method = authmethod_get(authlist);
404 if (method == NULL)
405 fatal("Permission denied (%s).", authlist);
406 authctxt->method = method;
407
408 /* reset the per method handler */
409 dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
410 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
411
412 /* and try new method */
413 if (method->userauth(authctxt) != 0) {
414 debug2("we sent a %s packet, wait for reply", method->name);
415 break;
416 } else {
417 debug2("we did not send a packet, disable method");
418 method->enabled = NULL;
419 }
420 }
421 }
422
423 /* ARGSUSED */
424 void
425 input_userauth_error(int type, u_int32_t seq, void *ctxt)
426 {
427 fatal("input_userauth_error: bad message during authentication: "
428 "type %d", type);
429 }
430
431 /* ARGSUSED */
432 void
433 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
434 {
435 char *msg, *raw, *lang;
436 u_int len;
437
438 debug3("input_userauth_banner");
439 raw = packet_get_string(&len);
440 lang = packet_get_string(NULL);
441 if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
442 if (len > 65536)
443 len = 65536;
444 msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
445 strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL);
446 fprintf(stderr, "%s", msg);
447 xfree(msg);
448 }
449 xfree(raw);
450 xfree(lang);
451 }
452
453 /* ARGSUSED */
454 void
455 input_userauth_success(int type, u_int32_t seq, void *ctxt)
456 {
457 Authctxt *authctxt = ctxt;
458 if (authctxt == NULL)
459 fatal("input_userauth_success: no authentication context");
460 if (authctxt->authlist) {
461 xfree(authctxt->authlist);
462 authctxt->authlist = NULL;
463 }
464 if (authctxt->methoddata) {
465 xfree(authctxt->methoddata);
466 authctxt->methoddata = NULL;
467 }
468 authctxt->success = 1; /* break out */
469 }
470
471 /* ARGSUSED */
472 void
473 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
474 {
475 Authctxt *authctxt = ctxt;
476 char *authlist = NULL;
477 int partial;
478
479 if (authctxt == NULL)
480 fatal("input_userauth_failure: no authentication context");
481
482 authlist = packet_get_string(NULL);
483 partial = packet_get_char();
484 packet_check_eom();
485
486 if (partial != 0)
487 logit("Authenticated with partial success.");
488 debug("Authentications that can continue: %s", authlist);
489
490 userauth(authctxt, authlist);
491 }
492
493 /* ARGSUSED */
494 void
495 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
496 {
497 Authctxt *authctxt = ctxt;
498 Key *key = NULL;
499 Identity *id = NULL;
500 Buffer b;
501 int pktype, sent = 0;
502 u_int alen, blen;
503 char *pkalg, *fp;
504 u_char *pkblob;
505
506 if (authctxt == NULL)
507 fatal("input_userauth_pk_ok: no authentication context");
508 if (datafellows & SSH_BUG_PKOK) {
509 /* this is similar to SSH_BUG_PKAUTH */
510 debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
511 pkblob = packet_get_string(&blen);
512 buffer_init(&b);
513 buffer_append(&b, pkblob, blen);
514 pkalg = buffer_get_string(&b, &alen);
515 buffer_free(&b);
516 } else {
517 pkalg = packet_get_string(&alen);
518 pkblob = packet_get_string(&blen);
519 }
520 packet_check_eom();
521
522 debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
523
524 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
525 debug("unknown pkalg %s", pkalg);
526 goto done;
527 }
528 if ((key = key_from_blob(pkblob, blen)) == NULL) {
529 debug("no key from blob. pkalg %s", pkalg);
530 goto done;
531 }
532 if (key->type != pktype) {
533 error("input_userauth_pk_ok: type mismatch "
534 "for decoded key (received %d, expected %d)",
535 key->type, pktype);
536 goto done;
537 }
538 fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
539 debug2("input_userauth_pk_ok: fp %s", fp);
540 xfree(fp);
541
542 /*
543 * search keys in the reverse order, because last candidate has been
544 * moved to the end of the queue. this also avoids confusion by
545 * duplicate keys
546 */
547 TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
548 if (key_equal(key, id->key)) {
549 sent = sign_and_send_pubkey(authctxt, id);
550 break;
551 }
552 }
553 done:
554 if (key != NULL)
555 key_free(key);
556 xfree(pkalg);
557 xfree(pkblob);
558
559 /* try another method if we did not send a packet */
560 if (sent == 0)
561 userauth(authctxt, NULL);
562 }
563
564 #ifdef GSSAPI
565 int
566 userauth_gssapi(Authctxt *authctxt)
567 {
568 Gssctxt *gssctxt = NULL;
569 static gss_OID_set gss_supported = NULL;
570 static u_int mech = 0;
571 OM_uint32 min;
572 int ok = 0;
573
574 /* Try one GSSAPI method at a time, rather than sending them all at
575 * once. */
576
577 if (gss_supported == NULL)
578 gss_indicate_mechs(&min, &gss_supported);
579
580 /* Check to see if the mechanism is usable before we offer it */
581 while (mech < gss_supported->count && !ok) {
582 /* My DER encoding requires length<128 */
583 if (gss_supported->elements[mech].length < 128 &&
584 ssh_gssapi_check_mechanism(&gssctxt,
585 &gss_supported->elements[mech], authctxt->host)) {
586 ok = 1; /* Mechanism works */
587 } else {
588 mech++;
589 }
590 }
591
592 if (!ok)
593 return 0;
594
595 authctxt->methoddata=(void *)gssctxt;
596
597 packet_start(SSH2_MSG_USERAUTH_REQUEST);
598 packet_put_cstring(authctxt->server_user);
599 packet_put_cstring(authctxt->service);
600 packet_put_cstring(authctxt->method->name);
601
602 packet_put_int(1);
603
604 packet_put_int((gss_supported->elements[mech].length) + 2);
605 packet_put_char(SSH_GSS_OIDTYPE);
606 packet_put_char(gss_supported->elements[mech].length);
607 packet_put_raw(gss_supported->elements[mech].elements,
608 gss_supported->elements[mech].length);
609
610 packet_send();
611
612 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
613 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
614 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
615 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
616
617 mech++; /* Move along to next candidate */
618
619 return 1;
620 }
621
622 static OM_uint32
623 process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
624 {
625 Authctxt *authctxt = ctxt;
626 Gssctxt *gssctxt = authctxt->methoddata;
627 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
628 gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
629 gss_buffer_desc gssbuf;
630 OM_uint32 status, ms, flags;
631 Buffer b;
632
633 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
634 recv_tok, &send_tok, &flags);
635
636 if (send_tok.length > 0) {
637 if (GSS_ERROR(status))
638 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
639 else
640 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
641
642 packet_put_string(send_tok.value, send_tok.length);
643 packet_send();
644 gss_release_buffer(&ms, &send_tok);
645 }
646
647 if (status == GSS_S_COMPLETE) {
648 /* send either complete or MIC, depending on mechanism */
649 if (!(flags & GSS_C_INTEG_FLAG)) {
650 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
651 packet_send();
652 } else {
653 ssh_gssapi_buildmic(&b, authctxt->server_user,
654 authctxt->service, "gssapi-with-mic");
655
656 gssbuf.value = buffer_ptr(&b);
657 gssbuf.length = buffer_len(&b);
658
659 status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
660
661 if (!GSS_ERROR(status)) {
662 packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
663 packet_put_string(mic.value, mic.length);
664
665 packet_send();
666 }
667
668 buffer_free(&b);
669 gss_release_buffer(&ms, &mic);
670 }
671 }
672
673 return status;
674 }
675
676 /* ARGSUSED */
677 void
678 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
679 {
680 Authctxt *authctxt = ctxt;
681 Gssctxt *gssctxt;
682 int oidlen;
683 char *oidv;
684
685 if (authctxt == NULL)
686 fatal("input_gssapi_response: no authentication context");
687 gssctxt = authctxt->methoddata;
688
689 /* Setup our OID */
690 oidv = packet_get_string(&oidlen);
691
692 if (oidlen <= 2 ||
693 oidv[0] != SSH_GSS_OIDTYPE ||
694 oidv[1] != oidlen - 2) {
695 xfree(oidv);
696 debug("Badly encoded mechanism OID received");
697 userauth(authctxt, NULL);
698 return;
699 }
700
701 if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
702 fatal("Server returned different OID than expected");
703
704 packet_check_eom();
705
706 xfree(oidv);
707
708 if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
709 /* Start again with next method on list */
710 debug("Trying to start again");
711 userauth(authctxt, NULL);
712 return;
713 }
714 }
715
716 /* ARGSUSED */
717 void
718 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
719 {
720 Authctxt *authctxt = ctxt;
721 gss_buffer_desc recv_tok;
722 OM_uint32 status;
723 u_int slen;
724
725 if (authctxt == NULL)
726 fatal("input_gssapi_response: no authentication context");
727
728 recv_tok.value = packet_get_string(&slen);
729 recv_tok.length = slen; /* safe typecast */
730
731 packet_check_eom();
732
733 status = process_gssapi_token(ctxt, &recv_tok);
734
735 xfree(recv_tok.value);
736
737 if (GSS_ERROR(status)) {
738 /* Start again with the next method in the list */
739 userauth(authctxt, NULL);
740 return;
741 }
742 }
743
744 /* ARGSUSED */
745 void
746 input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
747 {
748 Authctxt *authctxt = ctxt;
749 Gssctxt *gssctxt;
750 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
751 gss_buffer_desc recv_tok;
752 OM_uint32 status, ms;
753 u_int len;
754
755 if (authctxt == NULL)
756 fatal("input_gssapi_response: no authentication context");
757 gssctxt = authctxt->methoddata;
758
759 recv_tok.value = packet_get_string(&len);
760 recv_tok.length = len;
761
762 packet_check_eom();
763
764 /* Stick it into GSSAPI and see what it says */
765 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
766 &recv_tok, &send_tok, NULL);
767
768 xfree(recv_tok.value);
769 gss_release_buffer(&ms, &send_tok);
770
771 /* Server will be returning a failed packet after this one */
772 }
773
774 /* ARGSUSED */
775 void
776 input_gssapi_error(int type, u_int32_t plen, void *ctxt)
777 {
778 OM_uint32 maj, min;
779 char *msg;
780 char *lang;
781
782 maj=packet_get_int();
783 min=packet_get_int();
784 msg=packet_get_string(NULL);
785 lang=packet_get_string(NULL);
786
787 packet_check_eom();
788
789 debug("Server GSSAPI Error:\n%s", msg);
790 xfree(msg);
791 xfree(lang);
792 }
793 #endif /* GSSAPI */
794
795 int
796 userauth_none(Authctxt *authctxt)
797 {
798 /* initial userauth request */
799 packet_start(SSH2_MSG_USERAUTH_REQUEST);
800 packet_put_cstring(authctxt->server_user);
801 packet_put_cstring(authctxt->service);
802 packet_put_cstring(authctxt->method->name);
803 packet_send();
804 return 1;
805 }
806
807 int
808 userauth_passwd(Authctxt *authctxt)
809 {
810 static int attempt = 0;
811 char prompt[150];
812 char *password;
813
814 if (attempt++ >= options.number_of_password_prompts)
815 return 0;
816
817 if (attempt != 1)
818 error("Permission denied, please try again.");
819
820 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
821 authctxt->server_user, authctxt->host);
822 password = read_passphrase(prompt, 0);
823 packet_start(SSH2_MSG_USERAUTH_REQUEST);
824 packet_put_cstring(authctxt->server_user);
825 packet_put_cstring(authctxt->service);
826 packet_put_cstring(authctxt->method->name);
827 packet_put_char(0);
828 packet_put_cstring(password);
829 memset(password, 0, strlen(password));
830 xfree(password);
831 packet_add_padding(64);
832 packet_send();
833
834 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
835 &input_userauth_passwd_changereq);
836
837 return 1;
838 }
839
840 /*
841 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
842 */
843 /* ARGSUSED */
844 void
845 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
846 {
847 Authctxt *authctxt = ctxt;
848 char *info, *lang, *password = NULL, *retype = NULL;
849 char prompt[150];
850
851 debug2("input_userauth_passwd_changereq");
852
853 if (authctxt == NULL)
854 fatal("input_userauth_passwd_changereq: "
855 "no authentication context");
856
857 info = packet_get_string(NULL);
858 lang = packet_get_string(NULL);
859 if (strlen(info) > 0)
860 logit("%s", info);
861 xfree(info);
862 xfree(lang);
863 packet_start(SSH2_MSG_USERAUTH_REQUEST);
864 packet_put_cstring(authctxt->server_user);
865 packet_put_cstring(authctxt->service);
866 packet_put_cstring(authctxt->method->name);
867 packet_put_char(1); /* additional info */
868 snprintf(prompt, sizeof(prompt),
869 "Enter %.30s@%.128s's old password: ",
870 authctxt->server_user, authctxt->host);
871 password = read_passphrase(prompt, 0);
872 packet_put_cstring(password);
873 memset(password, 0, strlen(password));
874 xfree(password);
875 password = NULL;
876 while (password == NULL) {
877 snprintf(prompt, sizeof(prompt),
878 "Enter %.30s@%.128s's new password: ",
879 authctxt->server_user, authctxt->host);
880 password = read_passphrase(prompt, RP_ALLOW_EOF);
881 if (password == NULL) {
882 /* bail out */
883 return;
884 }
885 snprintf(prompt, sizeof(prompt),
886 "Retype %.30s@%.128s's new password: ",
887 authctxt->server_user, authctxt->host);
888 retype = read_passphrase(prompt, 0);
889 if (strcmp(password, retype) != 0) {
890 memset(password, 0, strlen(password));
891 xfree(password);
892 logit("Mismatch; try again, EOF to quit.");
893 password = NULL;
894 }
895 memset(retype, 0, strlen(retype));
896 xfree(retype);
897 }
898 packet_put_cstring(password);
899 memset(password, 0, strlen(password));
900 xfree(password);
901 packet_add_padding(64);
902 packet_send();
903
904 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
905 &input_userauth_passwd_changereq);
906 }
907
908 #ifdef JPAKE
909 static char *
910 pw_encrypt(const char *password, const char *crypt_scheme, const char *salt)
911 {
912 /* OpenBSD crypt(3) handles all of these */
913 if (strcmp(crypt_scheme, "crypt") == 0 ||
914 strcmp(crypt_scheme, "bcrypt") == 0 ||
915 strcmp(crypt_scheme, "md5crypt") == 0 ||
916 strcmp(crypt_scheme, "crypt-extended") == 0)
917 return xstrdup(crypt(password, salt));
918 error("%s: unsupported password encryption scheme \"%.100s\"",
919 __func__, crypt_scheme);
920 return NULL;
921 }
922
923 static BIGNUM *
924 jpake_password_to_secret(Authctxt *authctxt, const char *crypt_scheme,
925 const char *salt)
926 {
927 char prompt[256], *password, *crypted;
928 u_char *secret;
929 u_int secret_len;
930 BIGNUM *ret;
931
932 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password (JPAKE): ",
933 authctxt->server_user, authctxt->host);
934 password = read_passphrase(prompt, 0);
935
936 if ((crypted = pw_encrypt(password, crypt_scheme, salt)) == NULL) {
937 logit("Disabling %s authentication", authctxt->method->name);
938 authctxt->method->enabled = NULL;
939 /* Continue with an empty password to fail gracefully */
940 crypted = xstrdup("");
941 }
942
943 #ifdef JPAKE_DEBUG
944 debug3("%s: salt = %s", __func__, salt);
945 debug3("%s: scheme = %s", __func__, crypt_scheme);
946 debug3("%s: crypted = %s", __func__, crypted);
947 #endif
948
949 if (hash_buffer(crypted, strlen(crypted), EVP_sha256(),
950 &secret, &secret_len) != 0)
951 fatal("%s: hash_buffer", __func__);
952
953 bzero(password, strlen(password));
954 bzero(crypted, strlen(crypted));
955 xfree(password);
956 xfree(crypted);
957
958 if ((ret = BN_bin2bn(secret, secret_len, NULL)) == NULL)
959 fatal("%s: BN_bin2bn (secret)", __func__);
960 bzero(secret, secret_len);
961 xfree(secret);
962
963 return ret;
964 }
965
966 /* ARGSUSED */
967 void
968 input_userauth_jpake_server_step1(int type, u_int32_t seq, void *ctxt)
969 {
970 Authctxt *authctxt = ctxt;
971 struct jpake_ctx *pctx = authctxt->methoddata;
972 u_char *x3_proof, *x4_proof, *x2_s_proof;
973 u_int x3_proof_len, x4_proof_len, x2_s_proof_len;
974 char *crypt_scheme, *salt;
975
976 /* Disable this message */
977 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1, NULL);
978
979 if ((pctx->g_x3 = BN_new()) == NULL ||
980 (pctx->g_x4 = BN_new()) == NULL)
981 fatal("%s: BN_new", __func__);
982
983 /* Fetch step 1 values */
984 crypt_scheme = packet_get_string(NULL);
985 salt = packet_get_string(NULL);
986 pctx->server_id = packet_get_string(&pctx->server_id_len);
987 packet_get_bignum2(pctx->g_x3);
988 packet_get_bignum2(pctx->g_x4);
989 x3_proof = packet_get_string(&x3_proof_len);
990 x4_proof = packet_get_string(&x4_proof_len);
991 packet_check_eom();
992
993 JPAKE_DEBUG_CTX((pctx, "step 1 received in %s", __func__));
994
995 /* Obtain password and derive secret */
996 pctx->s = jpake_password_to_secret(authctxt, crypt_scheme, salt);
997 bzero(crypt_scheme, strlen(crypt_scheme));
998 bzero(salt, strlen(salt));
999 xfree(crypt_scheme);
1000 xfree(salt);
1001 JPAKE_DEBUG_BN((pctx->s, "%s: s = ", __func__));
1002
1003 /* Calculate step 2 values */
1004 jpake_step2(pctx->grp, pctx->s, pctx->g_x1,
1005 pctx->g_x3, pctx->g_x4, pctx->x2,
1006 pctx->server_id, pctx->server_id_len,
1007 pctx->client_id, pctx->client_id_len,
1008 x3_proof, x3_proof_len,
1009 x4_proof, x4_proof_len,
1010 &pctx->a,
1011 &x2_s_proof, &x2_s_proof_len);
1012
1013 bzero(x3_proof, x3_proof_len);
1014 bzero(x4_proof, x4_proof_len);
1015 xfree(x3_proof);
1016 xfree(x4_proof);
1017
1018 JPAKE_DEBUG_CTX((pctx, "step 2 sending in %s", __func__));
1019
1020 /* Send values for step 2 */
1021 packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2);
1022 packet_put_bignum2(pctx->a);
1023 packet_put_string(x2_s_proof, x2_s_proof_len);
1024 packet_send();
1025
1026 bzero(x2_s_proof, x2_s_proof_len);
1027 xfree(x2_s_proof);
1028
1029 /* Expect step 2 packet from peer */
1030 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2,
1031 input_userauth_jpake_server_step2);
1032 }
1033
1034 /* ARGSUSED */
1035 void
1036 input_userauth_jpake_server_step2(int type, u_int32_t seq, void *ctxt)
1037 {
1038 Authctxt *authctxt = ctxt;
1039 struct jpake_ctx *pctx = authctxt->methoddata;
1040 u_char *x4_s_proof;
1041 u_int x4_s_proof_len;
1042
1043 /* Disable this message */
1044 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2, NULL);
1045
1046 if ((pctx->b = BN_new()) == NULL)
1047 fatal("%s: BN_new", __func__);
1048
1049 /* Fetch step 2 values */
1050 packet_get_bignum2(pctx->b);
1051 x4_s_proof = packet_get_string(&x4_s_proof_len);
1052 packet_check_eom();
1053
1054 JPAKE_DEBUG_CTX((pctx, "step 2 received in %s", __func__));
1055
1056 /* Derive shared key and calculate confirmation hash */
1057 jpake_key_confirm(pctx->grp, pctx->s, pctx->b,
1058 pctx->x2, pctx->g_x1, pctx->g_x2, pctx->g_x3, pctx->g_x4,
1059 pctx->client_id, pctx->client_id_len,
1060 pctx->server_id, pctx->server_id_len,
1061 session_id2, session_id2_len,
1062 x4_s_proof, x4_s_proof_len,
1063 &pctx->k,
1064 &pctx->h_k_cid_sessid, &pctx->h_k_cid_sessid_len);
1065
1066 bzero(x4_s_proof, x4_s_proof_len);
1067 xfree(x4_s_proof);
1068
1069 JPAKE_DEBUG_CTX((pctx, "confirm sending in %s", __func__));
1070
1071 /* Send key confirmation proof */
1072 packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM);
1073 packet_put_string(pctx->h_k_cid_sessid, pctx->h_k_cid_sessid_len);
1074 packet_send();
1075
1076 /* Expect confirmation from peer */
1077 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM,
1078 input_userauth_jpake_server_confirm);
1079 }
1080
1081 /* ARGSUSED */
1082 void
1083 input_userauth_jpake_server_confirm(int type, u_int32_t seq, void *ctxt)
1084 {
1085 Authctxt *authctxt = ctxt;
1086 struct jpake_ctx *pctx = authctxt->methoddata;
1087
1088 /* Disable this message */
1089 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM, NULL);
1090
1091 pctx->h_k_sid_sessid = packet_get_string(&pctx->h_k_sid_sessid_len);
1092 packet_check_eom();
1093
1094 JPAKE_DEBUG_CTX((pctx, "confirm received in %s", __func__));
1095
1096 /* Verify expected confirmation hash */
1097 if (jpake_check_confirm(pctx->k,
1098 pctx->server_id, pctx->server_id_len,
1099 session_id2, session_id2_len,
1100 pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len) == 1)
1101 debug("%s: %s success", __func__, authctxt->method->name);
1102 else {
1103 debug("%s: confirmation mismatch", __func__);
1104 /* XXX stash this so if auth succeeds then we can warn/kill */
1105 }
1106
1107 userauth_jpake_cleanup(authctxt);
1108 }
1109 #endif /* JPAKE */
1110
1111 static int
1112 identity_sign(Identity *id, u_char **sigp, u_int *lenp,
1113 u_char *data, u_int datalen)
1114 {
1115 Key *prv;
1116 int ret;
1117
1118 /* the agent supports this key */
1119 if (id->ac)
1120 return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
1121 data, datalen));
1122 /*
1123 * we have already loaded the private key or
1124 * the private key is stored in external hardware
1125 */
1126 if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
1127 return (key_sign(id->key, sigp, lenp, data, datalen));
1128 /* load the private key from the file */
1129 if ((prv = load_identity_file(id->filename)) == NULL)
1130 return (-1);
1131 ret = key_sign(prv, sigp, lenp, data, datalen);
1132 key_free(prv);
1133 return (ret);
1134 }
1135
1136 static int
1137 sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1138 {
1139 Buffer b;
1140 u_char *blob, *signature;
1141 u_int bloblen, slen;
1142 u_int skip = 0;
1143 int ret = -1;
1144 int have_sig = 1;
1145
1146 debug3("sign_and_send_pubkey");
1147
1148 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1149 /* we cannot handle this key */
1150 debug3("sign_and_send_pubkey: cannot handle key");
1151 return 0;
1152 }
1153 /* data to be signed */
1154 buffer_init(&b);
1155 if (datafellows & SSH_OLD_SESSIONID) {
1156 buffer_append(&b, session_id2, session_id2_len);
1157 skip = session_id2_len;
1158 } else {
1159 buffer_put_string(&b, session_id2, session_id2_len);
1160 skip = buffer_len(&b);
1161 }
1162 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1163 buffer_put_cstring(&b, authctxt->server_user);
1164 buffer_put_cstring(&b,
1165 datafellows & SSH_BUG_PKSERVICE ?
1166 "ssh-userauth" :
1167 authctxt->service);
1168 if (datafellows & SSH_BUG_PKAUTH) {
1169 buffer_put_char(&b, have_sig);
1170 } else {
1171 buffer_put_cstring(&b, authctxt->method->name);
1172 buffer_put_char(&b, have_sig);
1173 buffer_put_cstring(&b, key_ssh_name(id->key));
1174 }
1175 buffer_put_string(&b, blob, bloblen);
1176
1177 /* generate signature */
1178 ret = identity_sign(id, &signature, &slen,
1179 buffer_ptr(&b), buffer_len(&b));
1180 if (ret == -1) {
1181 xfree(blob);
1182 buffer_free(&b);
1183 return 0;
1184 }
1185 #ifdef DEBUG_PK
1186 buffer_dump(&b);
1187 #endif
1188 if (datafellows & SSH_BUG_PKSERVICE) {
1189 buffer_clear(&b);
1190 buffer_append(&b, session_id2, session_id2_len);
1191 skip = session_id2_len;
1192 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1193 buffer_put_cstring(&b, authctxt->server_user);
1194 buffer_put_cstring(&b, authctxt->service);
1195 buffer_put_cstring(&b, authctxt->method->name);
1196 buffer_put_char(&b, have_sig);
1197 if (!(datafellows & SSH_BUG_PKAUTH))
1198 buffer_put_cstring(&b, key_ssh_name(id->key));
1199 buffer_put_string(&b, blob, bloblen);
1200 }
1201 xfree(blob);
1202
1203 /* append signature */
1204 buffer_put_string(&b, signature, slen);
1205 xfree(signature);
1206
1207 /* skip session id and packet type */
1208 if (buffer_len(&b) < skip + 1)
1209 fatal("userauth_pubkey: internal error");
1210 buffer_consume(&b, skip + 1);
1211
1212 /* put remaining data from buffer into packet */
1213 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1214 packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1215 buffer_free(&b);
1216 packet_send();
1217
1218 return 1;
1219 }
1220
1221 static int
1222 send_pubkey_test(Authctxt *authctxt, Identity *id)
1223 {
1224 u_char *blob;
1225 u_int bloblen, have_sig = 0;
1226
1227 debug3("send_pubkey_test");
1228
1229 if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1230 /* we cannot handle this key */
1231 debug3("send_pubkey_test: cannot handle key");
1232 return 0;
1233 }
1234 /* register callback for USERAUTH_PK_OK message */
1235 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1236
1237 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1238 packet_put_cstring(authctxt->server_user);
1239 packet_put_cstring(authctxt->service);
1240 packet_put_cstring(authctxt->method->name);
1241 packet_put_char(have_sig);
1242 if (!(datafellows & SSH_BUG_PKAUTH))
1243 packet_put_cstring(key_ssh_name(id->key));
1244 packet_put_string(blob, bloblen);
1245 xfree(blob);
1246 packet_send();
1247 return 1;
1248 }
1249
1250 static Key *
1251 load_identity_file(char *filename)
1252 {
1253 Key *private;
1254 char prompt[300], *passphrase;
1255 int perm_ok, quit, i;
1256 struct stat st;
1257
1258 if (stat(filename, &st) < 0) {
1259 debug3("no such identity: %s", filename);
1260 return NULL;
1261 }
1262 private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
1263 if (!perm_ok)
1264 return NULL;
1265 if (private == NULL) {
1266 if (options.batch_mode)
1267 return NULL;
1268 snprintf(prompt, sizeof prompt,
1269 "Enter passphrase for key '%.100s': ", filename);
1270 for (i = 0; i < options.number_of_password_prompts; i++) {
1271 passphrase = read_passphrase(prompt, 0);
1272 if (strcmp(passphrase, "") != 0) {
1273 private = key_load_private_type(KEY_UNSPEC,
1274 filename, passphrase, NULL, NULL);
1275 quit = 0;
1276 } else {
1277 debug2("no passphrase given, try next key");
1278 quit = 1;
1279 }
1280 memset(passphrase, 0, strlen(passphrase));
1281 xfree(passphrase);
1282 if (private != NULL || quit)
1283 break;
1284 debug2("bad passphrase given, try again...");
1285 }
1286 }
1287 return private;
1288 }
1289
1290 /*
1291 * try keys in the following order:
1292 * 1. agent keys that are found in the config file
1293 * 2. other agent keys
1294 * 3. keys that are only listed in the config file
1295 */
1296 static void
1297 pubkey_prepare(Authctxt *authctxt)
1298 {
1299 Identity *id;
1300 Idlist agent, files, *preferred;
1301 Key *key;
1302 AuthenticationConnection *ac;
1303 char *comment;
1304 int i, found;
1305
1306 TAILQ_INIT(&agent); /* keys from the agent */
1307 TAILQ_INIT(&files); /* keys from the config file */
1308 preferred = &authctxt->keys;
1309 TAILQ_INIT(preferred); /* preferred order of keys */
1310
1311 /* list of keys stored in the filesystem */
1312 for (i = 0; i < options.num_identity_files; i++) {
1313 key = options.identity_keys[i];
1314 if (key && key->type == KEY_RSA1)
1315 continue;
1316 options.identity_keys[i] = NULL;
1317 id = xcalloc(1, sizeof(*id));
1318 id->key = key;
1319 id->filename = xstrdup(options.identity_files[i]);
1320 TAILQ_INSERT_TAIL(&files, id, next);
1321 }
1322 /* list of keys supported by the agent */
1323 if ((ac = ssh_get_authentication_connection())) {
1324 for (key = ssh_get_first_identity(ac, &comment, 2);
1325 key != NULL;
1326 key = ssh_get_next_identity(ac, &comment, 2)) {
1327 found = 0;
1328 TAILQ_FOREACH(id, &files, next) {
1329 /* agent keys from the config file are preferred */
1330 if (key_equal(key, id->key)) {
1331 key_free(key);
1332 xfree(comment);
1333 TAILQ_REMOVE(&files, id, next);
1334 TAILQ_INSERT_TAIL(preferred, id, next);
1335 id->ac = ac;
1336 found = 1;
1337 break;
1338 }
1339 }
1340 if (!found && !options.identities_only) {
1341 id = xcalloc(1, sizeof(*id));
1342 id->key = key;
1343 id->filename = comment;
1344 id->ac = ac;
1345 TAILQ_INSERT_TAIL(&agent, id, next);
1346 }
1347 }
1348 /* append remaining agent keys */
1349 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1350 TAILQ_REMOVE(&agent, id, next);
1351 TAILQ_INSERT_TAIL(preferred, id, next);
1352 }
1353 authctxt->agent = ac;
1354 }
1355 /* append remaining keys from the config file */
1356 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1357 TAILQ_REMOVE(&files, id, next);
1358 TAILQ_INSERT_TAIL(preferred, id, next);
1359 }
1360 TAILQ_FOREACH(id, preferred, next) {
1361 debug2("key: %s (%p)", id->filename, id->key);
1362 }
1363 }
1364
1365 static void
1366 pubkey_cleanup(Authctxt *authctxt)
1367 {
1368 Identity *id;
1369
1370 if (authctxt->agent != NULL)
1371 ssh_close_authentication_connection(authctxt->agent);
1372 for (id = TAILQ_FIRST(&authctxt->keys); id;
1373 id = TAILQ_FIRST(&authctxt->keys)) {
1374 TAILQ_REMOVE(&authctxt->keys, id, next);
1375 if (id->key)
1376 key_free(id->key);
1377 if (id->filename)
1378 xfree(id->filename);
1379 xfree(id);
1380 }
1381 }
1382
1383 int
1384 userauth_pubkey(Authctxt *authctxt)
1385 {
1386 Identity *id;
1387 int sent = 0;
1388
1389 while ((id = TAILQ_FIRST(&authctxt->keys))) {
1390 if (id->tried++)
1391 return (0);
1392 /* move key to the end of the queue */
1393 TAILQ_REMOVE(&authctxt->keys, id, next);
1394 TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1395 /*
1396 * send a test message if we have the public key. for
1397 * encrypted keys we cannot do this and have to load the
1398 * private key instead
1399 */
1400 if (id->key && id->key->type != KEY_RSA1) {
1401 debug("Offering public key: %s", id->filename);
1402 sent = send_pubkey_test(authctxt, id);
1403 } else if (id->key == NULL) {
1404 debug("Trying private key: %s", id->filename);
1405 id->key = load_identity_file(id->filename);
1406 if (id->key != NULL) {
1407 id->isprivate = 1;
1408 sent = sign_and_send_pubkey(authctxt, id);
1409 key_free(id->key);
1410 id->key = NULL;
1411 }
1412 }
1413 if (sent)
1414 return (sent);
1415 }
1416 return (0);
1417 }
1418
1419 /*
1420 * Send userauth request message specifying keyboard-interactive method.
1421 */
1422 int
1423 userauth_kbdint(Authctxt *authctxt)
1424 {
1425 static int attempt = 0;
1426
1427 if (attempt++ >= options.number_of_password_prompts)
1428 return 0;
1429 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1430 if (attempt > 1 && !authctxt->info_req_seen) {
1431 debug3("userauth_kbdint: disable: no info_req_seen");
1432 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1433 return 0;
1434 }
1435
1436 debug2("userauth_kbdint");
1437 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1438 packet_put_cstring(authctxt->server_user);
1439 packet_put_cstring(authctxt->service);
1440 packet_put_cstring(authctxt->method->name);
1441 packet_put_cstring(""); /* lang */
1442 packet_put_cstring(options.kbd_interactive_devices ?
1443 options.kbd_interactive_devices : "");
1444 packet_send();
1445
1446 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1447 return 1;
1448 }
1449
1450 /*
1451 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1452 */
1453 void
1454 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1455 {
1456 Authctxt *authctxt = ctxt;
1457 char *name, *inst, *lang, *prompt, *response;
1458 u_int num_prompts, i;
1459 int echo = 0;
1460
1461 debug2("input_userauth_info_req");
1462
1463 if (authctxt == NULL)
1464 fatal("input_userauth_info_req: no authentication context");
1465
1466 authctxt->info_req_seen = 1;
1467
1468 name = packet_get_string(NULL);
1469 inst = packet_get_string(NULL);
1470 lang = packet_get_string(NULL);
1471 if (strlen(name) > 0)
1472 logit("%s", name);
1473 if (strlen(inst) > 0)
1474 logit("%s", inst);
1475 xfree(name);
1476 xfree(inst);
1477 xfree(lang);
1478
1479 num_prompts = packet_get_int();
1480 /*
1481 * Begin to build info response packet based on prompts requested.
1482 * We commit to providing the correct number of responses, so if
1483 * further on we run into a problem that prevents this, we have to
1484 * be sure and clean this up and send a correct error response.
1485 */
1486 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1487 packet_put_int(num_prompts);
1488
1489 debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1490 for (i = 0; i < num_prompts; i++) {
1491 prompt = packet_get_string(NULL);
1492 echo = packet_get_char();
1493
1494 response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1495
1496 packet_put_cstring(response);
1497 memset(response, 0, strlen(response));
1498 xfree(response);
1499 xfree(prompt);
1500 }
1501 packet_check_eom(); /* done with parsing incoming message. */
1502
1503 packet_add_padding(64);
1504 packet_send();
1505 }
1506
1507 static int
1508 ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1509 u_char *data, u_int datalen)
1510 {
1511 Buffer b;
1512 struct stat st;
1513 pid_t pid;
1514 int to[2], from[2], status, version = 2;
1515
1516 debug2("ssh_keysign called");
1517
1518 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1519 error("ssh_keysign: no installed: %s", strerror(errno));
1520 return -1;
1521 }
1522 if (fflush(stdout) != 0)
1523 error("ssh_keysign: fflush: %s", strerror(errno));
1524 if (pipe(to) < 0) {
1525 error("ssh_keysign: pipe: %s", strerror(errno));
1526 return -1;
1527 }
1528 if (pipe(from) < 0) {
1529 error("ssh_keysign: pipe: %s", strerror(errno));
1530 return -1;
1531 }
1532 if ((pid = fork()) < 0) {
1533 error("ssh_keysign: fork: %s", strerror(errno));
1534 return -1;
1535 }
1536 if (pid == 0) {
1537 permanently_drop_suid(getuid());
1538 close(from[0]);
1539 if (dup2(from[1], STDOUT_FILENO) < 0)
1540 fatal("ssh_keysign: dup2: %s", strerror(errno));
1541 close(to[1]);
1542 if (dup2(to[0], STDIN_FILENO) < 0)
1543 fatal("ssh_keysign: dup2: %s", strerror(errno));
1544 close(from[1]);
1545 close(to[0]);
1546 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1547 fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1548 strerror(errno));
1549 }
1550 close(from[1]);
1551 close(to[0]);
1552
1553 buffer_init(&b);
1554 buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1555 buffer_put_string(&b, data, datalen);
1556 if (ssh_msg_send(to[1], version, &b) == -1)
1557 fatal("ssh_keysign: couldn't send request");
1558
1559 if (ssh_msg_recv(from[0], &b) < 0) {
1560 error("ssh_keysign: no reply");
1561 buffer_free(&b);
1562 return -1;
1563 }
1564 close(from[0]);
1565 close(to[1]);
1566
1567 while (waitpid(pid, &status, 0) < 0)
1568 if (errno != EINTR)
1569 break;
1570
1571 if (buffer_get_char(&b) != version) {
1572 error("ssh_keysign: bad version");
1573 buffer_free(&b);
1574 return -1;
1575 }
1576 *sigp = buffer_get_string(&b, lenp);
1577 buffer_free(&b);
1578
1579 return 0;
1580 }
1581
1582 int
1583 userauth_hostbased(Authctxt *authctxt)
1584 {
1585 Key *private = NULL;
1586 Sensitive *sensitive = authctxt->sensitive;
1587 Buffer b;
1588 u_char *signature, *blob;
1589 char *chost, *pkalg, *p, myname[NI_MAXHOST];
1590 const char *service;
1591 u_int blen, slen;
1592 int ok, i, len, found = 0;
1593
1594 /* check for a useful key */
1595 for (i = 0; i < sensitive->nkeys; i++) {
1596 private = sensitive->keys[i];
1597 if (private && private->type != KEY_RSA1) {
1598 found = 1;
1599 /* we take and free the key */
1600 sensitive->keys[i] = NULL;
1601 break;
1602 }
1603 }
1604 if (!found) {
1605 debug("No more client hostkeys for hostbased authentication.");
1606 return 0;
1607 }
1608 if (key_to_blob(private, &blob, &blen) == 0) {
1609 key_free(private);
1610 return 0;
1611 }
1612 /* figure out a name for the client host */
1613 p = NULL;
1614 if (packet_connection_is_on_socket())
1615 p = get_local_name(packet_get_connection_in());
1616 if (p == NULL) {
1617 if (gethostname(myname, sizeof(myname)) == -1) {
1618 verbose("userauth_hostbased: gethostname: %s",
1619 strerror(errno));
1620 } else
1621 p = xstrdup(myname);
1622 }
1623 if (p == NULL) {
1624 error("userauth_hostbased: cannot get local ipaddr/name");
1625 key_free(private);
1626 xfree(blob);
1627 return 0;
1628 }
1629 len = strlen(p) + 2;
1630 xasprintf(&chost, "%s.", p);
1631 debug2("userauth_hostbased: chost %s", chost);
1632 xfree(p);
1633
1634 service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1635 authctxt->service;
1636 pkalg = xstrdup(key_ssh_name(private));
1637 buffer_init(&b);
1638 /* construct data */
1639 buffer_put_string(&b, session_id2, session_id2_len);
1640 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1641 buffer_put_cstring(&b, authctxt->server_user);
1642 buffer_put_cstring(&b, service);
1643 buffer_put_cstring(&b, authctxt->method->name);
1644 buffer_put_cstring(&b, pkalg);
1645 buffer_put_string(&b, blob, blen);
1646 buffer_put_cstring(&b, chost);
1647 buffer_put_cstring(&b, authctxt->local_user);
1648 #ifdef DEBUG_PK
1649 buffer_dump(&b);
1650 #endif
1651 if (sensitive->external_keysign)
1652 ok = ssh_keysign(private, &signature, &slen,
1653 buffer_ptr(&b), buffer_len(&b));
1654 else
1655 ok = key_sign(private, &signature, &slen,
1656 buffer_ptr(&b), buffer_len(&b));
1657 key_free(private);
1658 buffer_free(&b);
1659 if (ok != 0) {
1660 error("key_sign failed");
1661 xfree(chost);
1662 xfree(pkalg);
1663 xfree(blob);
1664 return 0;
1665 }
1666 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1667 packet_put_cstring(authctxt->server_user);
1668 packet_put_cstring(authctxt->service);
1669 packet_put_cstring(authctxt->method->name);
1670 packet_put_cstring(pkalg);
1671 packet_put_string(blob, blen);
1672 packet_put_cstring(chost);
1673 packet_put_cstring(authctxt->local_user);
1674 packet_put_string(signature, slen);
1675 memset(signature, 's', slen);
1676 xfree(signature);
1677 xfree(chost);
1678 xfree(pkalg);
1679 xfree(blob);
1680
1681 packet_send();
1682 return 1;
1683 }
1684
1685 #ifdef JPAKE
1686 int
1687 userauth_jpake(Authctxt *authctxt)
1688 {
1689 struct jpake_ctx *pctx;
1690 u_char *x1_proof, *x2_proof;
1691 u_int x1_proof_len, x2_proof_len;
1692 static int attempt = 0; /* XXX share with userauth_password's? */
1693
1694 if (attempt++ >= options.number_of_password_prompts)
1695 return 0;
1696 if (attempt != 1)
1697 error("Permission denied, please try again.");
1698
1699 if (authctxt->methoddata != NULL)
1700 fatal("%s: authctxt->methoddata already set (%p)",
1701 __func__, authctxt->methoddata);
1702
1703 authctxt->methoddata = pctx = jpake_new();
1704
1705 /*
1706 * Send request immediately, to get the protocol going while
1707 * we do the initial computations.
1708 */
1709 packet_start(SSH2_MSG_USERAUTH_REQUEST);
1710 packet_put_cstring(authctxt->server_user);
1711 packet_put_cstring(authctxt->service);
1712 packet_put_cstring(authctxt->method->name);
1713 packet_send();
1714 packet_write_wait();
1715
1716 jpake_step1(pctx->grp,
1717 &pctx->client_id, &pctx->client_id_len,
1718 &pctx->x1, &pctx->x2, &pctx->g_x1, &pctx->g_x2,
1719 &x1_proof, &x1_proof_len,
1720 &x2_proof, &x2_proof_len);
1721
1722 JPAKE_DEBUG_CTX((pctx, "step 1 sending in %s", __func__));
1723
1724 packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP1);
1725 packet_put_string(pctx->client_id, pctx->client_id_len);
1726 packet_put_bignum2(pctx->g_x1);
1727 packet_put_bignum2(pctx->g_x2);
1728 packet_put_string(x1_proof, x1_proof_len);
1729 packet_put_string(x2_proof, x2_proof_len);
1730 packet_send();
1731
1732 bzero(x1_proof, x1_proof_len);
1733 bzero(x2_proof, x2_proof_len);
1734 xfree(x1_proof);
1735 xfree(x2_proof);
1736
1737 /* Expect step 1 packet from peer */
1738 dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1,
1739 input_userauth_jpake_server_step1);
1740
1741 return 1;
1742 }
1743
1744 void
1745 userauth_jpake_cleanup(Authctxt *authctxt)
1746 {
1747 debug3("%s: clean up", __func__);
1748 if (authctxt->methoddata != NULL) {
1749 jpake_free(authctxt->methoddata);
1750 authctxt->methoddata = NULL;
1751 }
1752 }
1753 #endif /* JPAKE */
1754
1755 /* find auth method */
1756
1757 /*
1758 * given auth method name, if configurable options permit this method fill
1759 * in auth_ident field and return true, otherwise return false.
1760 */
1761 static int
1762 authmethod_is_enabled(Authmethod *method)
1763 {
1764 if (method == NULL)
1765 return 0;
1766 /* return false if options indicate this method is disabled */
1767 if (method->enabled == NULL || *method->enabled == 0)
1768 return 0;
1769 /* return false if batch mode is enabled but method needs interactive mode */
1770 if (method->batch_flag != NULL && *method->batch_flag != 0)
1771 return 0;
1772 return 1;
1773 }
1774
1775 static Authmethod *
1776 authmethod_lookup(const char *name)
1777 {
1778 Authmethod *method = NULL;
1779 if (name != NULL)
1780 for (method = authmethods; method->name != NULL; method++)
1781 if (strcmp(name, method->name) == 0)
1782 return method;
1783 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1784 return NULL;
1785 }
1786
1787 /* XXX internal state */
1788 static Authmethod *current = NULL;
1789 static char *supported = NULL;
1790 static char *preferred = NULL;
1791
1792 /*
1793 * Given the authentication method list sent by the server, return the
1794 * next method we should try. If the server initially sends a nil list,
1795 * use a built-in default list.
1796 */
1797 static Authmethod *
1798 authmethod_get(char *authlist)
1799 {
1800 char *name = NULL;
1801 u_int next;
1802
1803 /* Use a suitable default if we're passed a nil list. */
1804 if (authlist == NULL || strlen(authlist) == 0)
1805 authlist = options.preferred_authentications;
1806
1807 if (supported == NULL || strcmp(authlist, supported) != 0) {
1808 debug3("start over, passed a different list %s", authlist);
1809 if (supported != NULL)
1810 xfree(supported);
1811 supported = xstrdup(authlist);
1812 preferred = options.preferred_authentications;
1813 debug3("preferred %s", preferred);
1814 current = NULL;
1815 } else if (current != NULL && authmethod_is_enabled(current))
1816 return current;
1817
1818 for (;;) {
1819 if ((name = match_list(preferred, supported, &next)) == NULL) {
1820 debug("No more authentication methods to try.");
1821 current = NULL;
1822 return NULL;
1823 }
1824 preferred += next;
1825 debug3("authmethod_lookup %s", name);
1826 debug3("remaining preferred: %s", preferred);
1827 if ((current = authmethod_lookup(name)) != NULL &&
1828 authmethod_is_enabled(current)) {
1829 debug3("authmethod_is_enabled %s", name);
1830 debug("Next authentication method: %s", name);
1831 return current;
1832 }
1833 }
1834 }
1835
1836 static char *
1837 authmethods_get(void)
1838 {
1839 Authmethod *method = NULL;
1840 Buffer b;
1841 char *list;
1842
1843 buffer_init(&b);
1844 for (method = authmethods; method->name != NULL; method++) {
1845 if (authmethod_is_enabled(method)) {
1846 if (buffer_len(&b) > 0)
1847 buffer_append(&b, ",", 1);
1848 buffer_append(&b, method->name, strlen(method->name));
1849 }
1850 }
1851 buffer_append(&b, "\0", 1);
1852 list = xstrdup(buffer_ptr(&b));
1853 buffer_free(&b);
1854 return list;
1855 }
1856
DragonFly BSD