1 /* $OpenBSD: kex.c,v 1.86 2010/09/22 05:01:29 djm Exp $ */
2 /*
3 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "includes.h"
27
28 #include <sys/param.h>
29
30 #include <signal.h>
31 #include <stdarg.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35
36 #include <openssl/crypto.h>
37
38 #include "xmalloc.h"
39 #include "ssh2.h"
40 #include "buffer.h"
41 #include "packet.h"
42 #include "compat.h"
43 #include "cipher.h"
44 #include "key.h"
45 #include "kex.h"
46 #include "log.h"
47 #include "mac.h"
48 #include "match.h"
49 #include "dispatch.h"
50 #include "monitor.h"
51 #include "roaming.h"
52
53 #if OPENSSL_VERSION_NUMBER >= 0x00907000L
54 # if defined(HAVE_EVP_SHA256)
55 # define evp_ssh_sha256 EVP_sha256
56 # else
57 extern const EVP_MD *evp_ssh_sha256(void);
58 # endif
59 #endif
60
61 /* prototype */
62 static void kex_kexinit_finish(Kex *);
63 static void kex_choose_conf(Kex *);
64
65 /* Validate KEX method name list */
66 int
kex_names_valid(const char * names)67 kex_names_valid(const char *names)
68 {
69 char *s, *cp, *p;
70
71 if (names == NULL || strcmp(names, "") == 0)
72 return 0;
73 s = cp = xstrdup(names);
74 for ((p = strsep(&cp, ",")); p && *p != '\0';
75 (p = strsep(&cp, ","))) {
76 if (strcmp(p, KEX_DHGEX_SHA256) != 0 &&
77 strcmp(p, KEX_DHGEX_SHA1) != 0 &&
78 strcmp(p, KEX_DH14) != 0 &&
79 strcmp(p, KEX_DH1) != 0 &&
80 (strncmp(p, KEX_ECDH_SHA2_STEM,
81 sizeof(KEX_ECDH_SHA2_STEM) - 1) != 0 ||
82 kex_ecdh_name_to_nid(p) == -1)) {
83 error("Unsupported KEX algorithm \"%.100s\"", p);
84 xfree(s);
85 return 0;
86 }
87 }
88 debug3("kex names ok: [%s]", names);
89 xfree(s);
90 return 1;
91 }
92
93 /* put algorithm proposal into buffer */
94 static void
kex_prop2buf(Buffer * b,char * proposal[PROPOSAL_MAX])95 kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX])
96 {
97 u_int i;
98
99 buffer_clear(b);
100 /*
101 * add a dummy cookie, the cookie will be overwritten by
102 * kex_send_kexinit(), each time a kexinit is set
103 */
104 for (i = 0; i < KEX_COOKIE_LEN; i++)
105 buffer_put_char(b, 0);
106 for (i = 0; i < PROPOSAL_MAX; i++)
107 buffer_put_cstring(b, proposal[i]);
108 buffer_put_char(b, 0); /* first_kex_packet_follows */
109 buffer_put_int(b, 0); /* uint32 reserved */
110 }
111
112 /* parse buffer and return algorithm proposal */
113 static char **
kex_buf2prop(Buffer * raw,int * first_kex_follows)114 kex_buf2prop(Buffer *raw, int *first_kex_follows)
115 {
116 Buffer b;
117 u_int i;
118 char **proposal;
119
120 proposal = xcalloc(PROPOSAL_MAX, sizeof(char *));
121
122 buffer_init(&b);
123 buffer_append(&b, buffer_ptr(raw), buffer_len(raw));
124 /* skip cookie */
125 for (i = 0; i < KEX_COOKIE_LEN; i++)
126 buffer_get_char(&b);
127 /* extract kex init proposal strings */
128 for (i = 0; i < PROPOSAL_MAX; i++) {
129 proposal[i] = buffer_get_cstring(&b,NULL);
130 debug2("kex_parse_kexinit: %s", proposal[i]);
131 }
132 /* first kex follows / reserved */
133 i = buffer_get_char(&b);
134 if (first_kex_follows != NULL)
135 *first_kex_follows = i;
136 debug2("kex_parse_kexinit: first_kex_follows %d ", i);
137 i = buffer_get_int(&b);
138 debug2("kex_parse_kexinit: reserved %u ", i);
139 buffer_free(&b);
140 return proposal;
141 }
142
143 static void
kex_prop_free(char ** proposal)144 kex_prop_free(char **proposal)
145 {
146 u_int i;
147
148 for (i = 0; i < PROPOSAL_MAX; i++)
149 xfree(proposal[i]);
150 xfree(proposal);
151 }
152
153 /* ARGSUSED */
154 static void
kex_protocol_error(int type,u_int32_t seq,void * ctxt)155 kex_protocol_error(int type, u_int32_t seq, void *ctxt)
156 {
157 error("Hm, kex protocol error: type %d seq %u", type, seq);
158 }
159
160 static void
kex_reset_dispatch(void)161 kex_reset_dispatch(void)
162 {
163 dispatch_range(SSH2_MSG_TRANSPORT_MIN,
164 SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error);
165 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
166 }
167
168 void
kex_finish(Kex * kex)169 kex_finish(Kex *kex)
170 {
171 kex_reset_dispatch();
172
173 packet_start(SSH2_MSG_NEWKEYS);
174 packet_send();
175 /* packet_write_wait(); */
176 debug("SSH2_MSG_NEWKEYS sent");
177
178 debug("expecting SSH2_MSG_NEWKEYS");
179 packet_read_expect(SSH2_MSG_NEWKEYS);
180 packet_check_eom();
181 debug("SSH2_MSG_NEWKEYS received");
182
183 kex->done = 1;
184 buffer_clear(&kex->peer);
185 /* buffer_clear(&kex->my); */
186 kex->flags &= ~KEX_INIT_SENT;
187 xfree(kex->name);
188 kex->name = NULL;
189 }
190
191 void
kex_send_kexinit(Kex * kex)192 kex_send_kexinit(Kex *kex)
193 {
194 u_int32_t rnd = 0;
195 u_char *cookie;
196 u_int i;
197
198 if (kex == NULL) {
199 error("kex_send_kexinit: no kex, cannot rekey");
200 return;
201 }
202 if (kex->flags & KEX_INIT_SENT) {
203 debug("KEX_INIT_SENT");
204 return;
205 }
206 kex->done = 0;
207
208 /* generate a random cookie */
209 if (buffer_len(&kex->my) < KEX_COOKIE_LEN)
210 fatal("kex_send_kexinit: kex proposal too short");
211 cookie = buffer_ptr(&kex->my);
212 for (i = 0; i < KEX_COOKIE_LEN; i++) {
213 if (i % 4 == 0)
214 rnd = arc4random();
215 cookie[i] = rnd;
216 rnd >>= 8;
217 }
218 packet_start(SSH2_MSG_KEXINIT);
219 packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my));
220 packet_send();
221 debug("SSH2_MSG_KEXINIT sent");
222 kex->flags |= KEX_INIT_SENT;
223 }
224
225 /* ARGSUSED */
226 void
kex_input_kexinit(int type,u_int32_t seq,void * ctxt)227 kex_input_kexinit(int type, u_int32_t seq, void *ctxt)
228 {
229 char *ptr;
230 u_int i, dlen;
231 Kex *kex = (Kex *)ctxt;
232
233 debug("SSH2_MSG_KEXINIT received");
234 if (kex == NULL)
235 fatal("kex_input_kexinit: no kex, cannot rekey");
236
237 ptr = packet_get_raw(&dlen);
238 buffer_append(&kex->peer, ptr, dlen);
239
240 /* discard packet */
241 for (i = 0; i < KEX_COOKIE_LEN; i++)
242 packet_get_char();
243 for (i = 0; i < PROPOSAL_MAX; i++)
244 xfree(packet_get_string(NULL));
245 (void) packet_get_char();
246 (void) packet_get_int();
247 packet_check_eom();
248
249 kex_kexinit_finish(kex);
250 }
251
252 Kex *
kex_setup(char * proposal[PROPOSAL_MAX])253 kex_setup(char *proposal[PROPOSAL_MAX])
254 {
255 Kex *kex;
256
257 kex = xcalloc(1, sizeof(*kex));
258 buffer_init(&kex->peer);
259 buffer_init(&kex->my);
260 kex_prop2buf(&kex->my, proposal);
261 kex->done = 0;
262
263 kex_send_kexinit(kex); /* we start */
264 kex_reset_dispatch();
265
266 return kex;
267 }
268
269 static void
kex_kexinit_finish(Kex * kex)270 kex_kexinit_finish(Kex *kex)
271 {
272 if (!(kex->flags & KEX_INIT_SENT))
273 kex_send_kexinit(kex);
274
275 kex_choose_conf(kex);
276
277 if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX &&
278 kex->kex[kex->kex_type] != NULL) {
279 (kex->kex[kex->kex_type])(kex);
280 } else {
281 fatal("Unsupported key exchange %d", kex->kex_type);
282 }
283 }
284
285 static void
choose_enc(Enc * enc,char * client,char * server)286 choose_enc(Enc *enc, char *client, char *server)
287 {
288 char *name = match_list(client, server, NULL);
289 if (name == NULL)
290 fatal("no matching cipher found: client %s server %s",
291 client, server);
292 if ((enc->cipher = cipher_by_name(name)) == NULL)
293 fatal("matching cipher is not supported: %s", name);
294 enc->name = name;
295 enc->enabled = 0;
296 enc->iv = NULL;
297 enc->key = NULL;
298 enc->key_len = cipher_keylen(enc->cipher);
299 enc->block_size = cipher_blocksize(enc->cipher);
300 }
301
302 static void
choose_mac(Mac * mac,char * client,char * server)303 choose_mac(Mac *mac, char *client, char *server)
304 {
305 char *name = match_list(client, server, NULL);
306 if (name == NULL)
307 fatal("no matching mac found: client %s server %s",
308 client, server);
309 if (mac_setup(mac, name) < 0)
310 fatal("unsupported mac %s", name);
311 /* truncate the key */
312 if (datafellows & SSH_BUG_HMAC)
313 mac->key_len = 16;
314 mac->name = name;
315 mac->key = NULL;
316 mac->enabled = 0;
317 }
318
319 static void
choose_comp(Comp * comp,char * client,char * server)320 choose_comp(Comp *comp, char *client, char *server)
321 {
322 char *name = match_list(client, server, NULL);
323 if (name == NULL)
324 fatal("no matching comp found: client %s server %s", client, server);
325 if (strcmp(name, "zlib@openssh.com") == 0) {
326 comp->type = COMP_DELAYED;
327 } else if (strcmp(name, "zlib") == 0) {
328 comp->type = COMP_ZLIB;
329 } else if (strcmp(name, "none") == 0) {
330 comp->type = COMP_NONE;
331 } else {
332 fatal("unsupported comp %s", name);
333 }
334 comp->name = name;
335 }
336
337 static void
choose_kex(Kex * k,char * client,char * server)338 choose_kex(Kex *k, char *client, char *server)
339 {
340 k->name = match_list(client, server, NULL);
341 if (k->name == NULL)
342 fatal("Unable to negotiate a key exchange method");
343 if (strcmp(k->name, KEX_DH1) == 0) {
344 k->kex_type = KEX_DH_GRP1_SHA1;
345 k->evp_md = EVP_sha1();
346 } else if (strcmp(k->name, KEX_DH14) == 0) {
347 k->kex_type = KEX_DH_GRP14_SHA1;
348 k->evp_md = EVP_sha1();
349 } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) {
350 k->kex_type = KEX_DH_GEX_SHA1;
351 k->evp_md = EVP_sha1();
352 #if OPENSSL_VERSION_NUMBER >= 0x00907000L
353 } else if (strcmp(k->name, KEX_DHGEX_SHA256) == 0) {
354 k->kex_type = KEX_DH_GEX_SHA256;
355 k->evp_md = evp_ssh_sha256();
356 } else if (strncmp(k->name, KEX_ECDH_SHA2_STEM,
357 sizeof(KEX_ECDH_SHA2_STEM) - 1) == 0) {
358 k->kex_type = KEX_ECDH_SHA2;
359 k->evp_md = kex_ecdh_name_to_evpmd(k->name);
360 #endif
361 } else
362 fatal("bad kex alg %s", k->name);
363 }
364
365 static void
choose_hostkeyalg(Kex * k,char * client,char * server)366 choose_hostkeyalg(Kex *k, char *client, char *server)
367 {
368 char *hostkeyalg = match_list(client, server, NULL);
369 if (hostkeyalg == NULL)
370 fatal("no hostkey alg");
371 k->hostkey_type = key_type_from_name(hostkeyalg);
372 if (k->hostkey_type == KEY_UNSPEC)
373 fatal("bad hostkey alg '%s'", hostkeyalg);
374 xfree(hostkeyalg);
375 }
376
377 static int
proposals_match(char * my[PROPOSAL_MAX],char * peer[PROPOSAL_MAX])378 proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX])
379 {
380 static int check[] = {
381 PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1
382 };
383 int *idx;
384 char *p;
385
386 for (idx = &check[0]; *idx != -1; idx++) {
387 if ((p = strchr(my[*idx], ',')) != NULL)
388 *p = '\0';
389 if ((p = strchr(peer[*idx], ',')) != NULL)
390 *p = '\0';
391 if (strcmp(my[*idx], peer[*idx]) != 0) {
392 debug2("proposal mismatch: my %s peer %s",
393 my[*idx], peer[*idx]);
394 return (0);
395 }
396 }
397 debug2("proposals match");
398 return (1);
399 }
400
401 static void
kex_choose_conf(Kex * kex)402 kex_choose_conf(Kex *kex)
403 {
404 Newkeys *newkeys;
405 char **my, **peer;
406 char **cprop, **sprop;
407 int nenc, nmac, ncomp;
408 u_int mode, ctos, need;
409 int first_kex_follows, type;
410
411 my = kex_buf2prop(&kex->my, NULL);
412 peer = kex_buf2prop(&kex->peer, &first_kex_follows);
413
414 if (kex->server) {
415 cprop=peer;
416 sprop=my;
417 } else {
418 cprop=my;
419 sprop=peer;
420 }
421
422 /* Check whether server offers roaming */
423 if (!kex->server) {
424 char *roaming;
425 roaming = match_list(KEX_RESUME, peer[PROPOSAL_KEX_ALGS], NULL);
426 if (roaming) {
427 kex->roaming = 1;
428 xfree(roaming);
429 }
430 }
431
432 /* Algorithm Negotiation */
433 for (mode = 0; mode < MODE_MAX; mode++) {
434 newkeys = xcalloc(1, sizeof(*newkeys));
435 kex->newkeys[mode] = newkeys;
436 ctos = (!kex->server && mode == MODE_OUT) ||
437 (kex->server && mode == MODE_IN);
438 nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC;
439 nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC;
440 ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
441 choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]);
442 choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]);
443 choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]);
444 debug("kex: %s %s %s %s",
445 ctos ? "client->server" : "server->client",
446 newkeys->enc.name,
447 newkeys->mac.name,
448 newkeys->comp.name);
449 }
450 choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
451 choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
452 sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
453 need = 0;
454 for (mode = 0; mode < MODE_MAX; mode++) {
455 newkeys = kex->newkeys[mode];
456 if (need < newkeys->enc.key_len)
457 need = newkeys->enc.key_len;
458 if (need < newkeys->enc.block_size)
459 need = newkeys->enc.block_size;
460 if (need < newkeys->mac.key_len)
461 need = newkeys->mac.key_len;
462 }
463 /* XXX need runden? */
464 kex->we_need = need;
465
466 /* ignore the next message if the proposals do not match */
467 if (first_kex_follows && !proposals_match(my, peer) &&
468 !(datafellows & SSH_BUG_FIRSTKEX)) {
469 type = packet_read();
470 debug2("skipping next packet (type %u)", type);
471 }
472
473 kex_prop_free(my);
474 kex_prop_free(peer);
475 }
476
477 static u_char *
derive_key(Kex * kex,int id,u_int need,u_char * hash,u_int hashlen,BIGNUM * shared_secret)478 derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen,
479 BIGNUM *shared_secret)
480 {
481 Buffer b;
482 EVP_MD_CTX md;
483 char c = id;
484 u_int have;
485 int mdsz;
486 u_char *digest;
487
488 if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0)
489 fatal("bad kex md size %d", mdsz);
490 digest = xmalloc(roundup(need, mdsz));
491
492 buffer_init(&b);
493 buffer_put_bignum2(&b, shared_secret);
494
495 /* K1 = HASH(K || H || "A" || session_id) */
496 EVP_DigestInit(&md, kex->evp_md);
497 if (!(datafellows & SSH_BUG_DERIVEKEY))
498 EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
499 EVP_DigestUpdate(&md, hash, hashlen);
500 EVP_DigestUpdate(&md, &c, 1);
501 EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len);
502 EVP_DigestFinal(&md, digest, NULL);
503
504 /*
505 * expand key:
506 * Kn = HASH(K || H || K1 || K2 || ... || Kn-1)
507 * Key = K1 || K2 || ... || Kn
508 */
509 for (have = mdsz; need > have; have += mdsz) {
510 EVP_DigestInit(&md, kex->evp_md);
511 if (!(datafellows & SSH_BUG_DERIVEKEY))
512 EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
513 EVP_DigestUpdate(&md, hash, hashlen);
514 EVP_DigestUpdate(&md, digest, have);
515 EVP_DigestFinal(&md, digest + have, NULL);
516 }
517 buffer_free(&b);
518 #ifdef DEBUG_KEX
519 fprintf(stderr, "key '%c'== ", c);
520 dump_digest("key", digest, need);
521 #endif
522 return digest;
523 }
524
525 Newkeys *current_keys[MODE_MAX];
526
527 #define NKEYS 6
528 void
kex_derive_keys(Kex * kex,u_char * hash,u_int hashlen,BIGNUM * shared_secret)529 kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret)
530 {
531 u_char *keys[NKEYS];
532 u_int i, mode, ctos;
533
534 for (i = 0; i < NKEYS; i++) {
535 keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen,
536 shared_secret);
537 }
538
539 debug2("kex_derive_keys");
540 for (mode = 0; mode < MODE_MAX; mode++) {
541 current_keys[mode] = kex->newkeys[mode];
542 kex->newkeys[mode] = NULL;
543 ctos = (!kex->server && mode == MODE_OUT) ||
544 (kex->server && mode == MODE_IN);
545 current_keys[mode]->enc.iv = keys[ctos ? 0 : 1];
546 current_keys[mode]->enc.key = keys[ctos ? 2 : 3];
547 current_keys[mode]->mac.key = keys[ctos ? 4 : 5];
548 }
549 }
550
551 Newkeys *
kex_get_newkeys(int mode)552 kex_get_newkeys(int mode)
553 {
554 Newkeys *ret;
555
556 ret = current_keys[mode];
557 current_keys[mode] = NULL;
558 return ret;
559 }
560
561 void
derive_ssh1_session_id(BIGNUM * host_modulus,BIGNUM * server_modulus,u_int8_t cookie[8],u_int8_t id[16])562 derive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus,
563 u_int8_t cookie[8], u_int8_t id[16])
564 {
565 const EVP_MD *evp_md = EVP_md5();
566 EVP_MD_CTX md;
567 u_int8_t nbuf[2048], obuf[EVP_MAX_MD_SIZE];
568 int len;
569
570 EVP_DigestInit(&md, evp_md);
571
572 len = BN_num_bytes(host_modulus);
573 if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
574 fatal("%s: bad host modulus (len %d)", __func__, len);
575 BN_bn2bin(host_modulus, nbuf);
576 EVP_DigestUpdate(&md, nbuf, len);
577
578 len = BN_num_bytes(server_modulus);
579 if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
580 fatal("%s: bad server modulus (len %d)", __func__, len);
581 BN_bn2bin(server_modulus, nbuf);
582 EVP_DigestUpdate(&md, nbuf, len);
583
584 EVP_DigestUpdate(&md, cookie, 8);
585
586 EVP_DigestFinal(&md, obuf, NULL);
587 memcpy(id, obuf, 16);
588
589 memset(nbuf, 0, sizeof(nbuf));
590 memset(obuf, 0, sizeof(obuf));
591 memset(&md, 0, sizeof(md));
592 }
593
594 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
595 void
dump_digest(char * msg,u_char * digest,int len)596 dump_digest(char *msg, u_char *digest, int len)
597 {
598 int i;
599
600 fprintf(stderr, "%s\n", msg);
601 for (i = 0; i < len; i++) {
602 fprintf(stderr, "%02x", digest[i]);
603 if (i%32 == 31)
604 fprintf(stderr, "\n");
605 else if (i%8 == 7)
606 fprintf(stderr, " ");
607 }
608 fprintf(stderr, "\n");
609 }
610 #endif
611