1 /* ssl/s23_srvr.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58 /* ====================================================================
59 * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
60 *
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
63 * are met:
64 *
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
67 *
68 * 2. Redistributions in binary form must reproduce the above copyright
69 * notice, this list of conditions and the following disclaimer in
70 * the documentation and/or other materials provided with the
71 * distribution.
72 *
73 * 3. All advertising materials mentioning features or use of this
74 * software must display the following acknowledgment:
75 * "This product includes software developed by the OpenSSL Project
76 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77 *
78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79 * endorse or promote products derived from this software without
80 * prior written permission. For written permission, please contact
81 * openssl-core@openssl.org.
82 *
83 * 5. Products derived from this software may not be called "OpenSSL"
84 * nor may "OpenSSL" appear in their names without prior written
85 * permission of the OpenSSL Project.
86 *
87 * 6. Redistributions of any form whatsoever must retain the following
88 * acknowledgment:
89 * "This product includes software developed by the OpenSSL Project
90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91 *
92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103 * OF THE POSSIBILITY OF SUCH DAMAGE.
104 * ====================================================================
105 *
106 * This product includes cryptographic software written by Eric Young
107 * (eay@cryptsoft.com). This product includes software written by Tim
108 * Hudson (tjh@cryptsoft.com).
109 *
110 */
111
112 #include <stdio.h>
113 #include "ssl_locl.h"
114 #include <openssl/buffer.h>
115 #include <openssl/rand.h>
116 #include <openssl/objects.h>
117 #include <openssl/evp.h>
118
119 static SSL_METHOD *ssl23_get_server_method(int ver);
120 int ssl23_get_client_hello(SSL *s);
ssl23_get_server_method(int ver)121 static SSL_METHOD *ssl23_get_server_method(int ver)
122 {
123 #ifndef OPENSSL_NO_SSL2
124 if (ver == SSL2_VERSION)
125 return (SSLv2_server_method());
126 #endif
127 #ifndef OPENSSL_NO_SSL3
128 if (ver == SSL3_VERSION)
129 return (SSLv3_server_method());
130 #endif
131 if (ver == TLS1_VERSION)
132 return (TLSv1_server_method());
133 else
134 return (NULL);
135 }
136
IMPLEMENT_ssl23_meth_func(SSLv23_server_method,ssl23_accept,ssl_undefined_function,ssl23_get_server_method)137 IMPLEMENT_ssl23_meth_func(SSLv23_server_method,
138 ssl23_accept,
139 ssl_undefined_function, ssl23_get_server_method)
140
141 int ssl23_accept(SSL *s)
142 {
143 BUF_MEM *buf;
144 unsigned long Time = (unsigned long)time(NULL);
145 void (*cb) (const SSL *ssl, int type, int val) = NULL;
146 int ret = -1;
147 int new_state, state;
148
149 RAND_add(&Time, sizeof(Time), 0);
150 ERR_clear_error();
151 clear_sys_error();
152
153 if (s->info_callback != NULL)
154 cb = s->info_callback;
155 else if (s->ctx->info_callback != NULL)
156 cb = s->ctx->info_callback;
157
158 s->in_handshake++;
159 if (!SSL_in_init(s) || SSL_in_before(s))
160 SSL_clear(s);
161
162 for (;;) {
163 state = s->state;
164
165 switch (s->state) {
166 case SSL_ST_BEFORE:
167 case SSL_ST_ACCEPT:
168 case SSL_ST_BEFORE | SSL_ST_ACCEPT:
169 case SSL_ST_OK | SSL_ST_ACCEPT:
170
171 s->server = 1;
172 if (cb != NULL)
173 cb(s, SSL_CB_HANDSHAKE_START, 1);
174
175 /* s->version=SSL3_VERSION; */
176 s->type = SSL_ST_ACCEPT;
177
178 if (s->init_buf == NULL) {
179 if ((buf = BUF_MEM_new()) == NULL) {
180 ret = -1;
181 goto end;
182 }
183 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
184 ret = -1;
185 goto end;
186 }
187 s->init_buf = buf;
188 }
189
190 ssl3_init_finished_mac(s);
191
192 s->state = SSL23_ST_SR_CLNT_HELLO_A;
193 s->ctx->stats.sess_accept++;
194 s->init_num = 0;
195 break;
196
197 case SSL23_ST_SR_CLNT_HELLO_A:
198 case SSL23_ST_SR_CLNT_HELLO_B:
199
200 s->shutdown = 0;
201 ret = ssl23_get_client_hello(s);
202 if (ret >= 0)
203 cb = NULL;
204 goto end;
205 /* break; */
206
207 default:
208 SSLerr(SSL_F_SSL23_ACCEPT, SSL_R_UNKNOWN_STATE);
209 ret = -1;
210 goto end;
211 /* break; */
212 }
213
214 if ((cb != NULL) && (s->state != state)) {
215 new_state = s->state;
216 s->state = state;
217 cb(s, SSL_CB_ACCEPT_LOOP, 1);
218 s->state = new_state;
219 }
220 }
221 end:
222 s->in_handshake--;
223 if (cb != NULL)
224 cb(s, SSL_CB_ACCEPT_EXIT, ret);
225 return (ret);
226 }
227
ssl23_get_client_hello(SSL * s)228 int ssl23_get_client_hello(SSL *s)
229 {
230 /*-
231 * Request this many bytes in initial read.
232 * We can detect SSL 3.0/TLS 1.0 Client Hellos
233 * ('type == 3') correctly only when the following
234 * is in a single record, which is not guaranteed by
235 * the protocol specification:
236 * Byte Content
237 * 0 type \
238 * 1/2 version > record header
239 * 3/4 length /
240 * 5 msg_type \
241 * 6-8 length > Client Hello message
242 * 9/10 client_version /
243 */
244 char buf_space[11];
245 char *buf = &(buf_space[0]);
246 unsigned char *p, *d, *d_len, *dd;
247 unsigned int i;
248 unsigned int csl, sil, cl;
249 int n = 0, j;
250 int type = 0;
251 int v[2];
252
253 if (s->state == SSL23_ST_SR_CLNT_HELLO_A) {
254 /* read the initial header */
255 v[0] = v[1] = 0;
256
257 if (!ssl3_setup_buffers(s))
258 goto err;
259
260 n = ssl23_read_bytes(s, sizeof buf_space);
261 if (n != sizeof buf_space)
262 return (n); /* n == -1 || n == 0 */
263
264 p = s->packet;
265
266 memcpy(buf, p, n);
267
268 if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO)) {
269 /*
270 * SSLv2 header
271 */
272 if ((p[3] == 0x00) && (p[4] == 0x02)) {
273 v[0] = p[3];
274 v[1] = p[4];
275 /* SSLv2 */
276 if (!(s->options & SSL_OP_NO_SSLv2))
277 type = 1;
278 } else if (p[3] == SSL3_VERSION_MAJOR) {
279 v[0] = p[3];
280 v[1] = p[4];
281 /* SSLv3/TLSv1 */
282 if (p[4] >= TLS1_VERSION_MINOR) {
283 if (!(s->options & SSL_OP_NO_TLSv1)) {
284 s->version = TLS1_VERSION;
285 /*
286 * type=2;
287 *//*
288 * done later to survive restarts
289 */
290 s->state = SSL23_ST_SR_CLNT_HELLO_B;
291 } else if (!(s->options & SSL_OP_NO_SSLv3)) {
292 s->version = SSL3_VERSION;
293 /* type=2; */
294 s->state = SSL23_ST_SR_CLNT_HELLO_B;
295 } else if (!(s->options & SSL_OP_NO_SSLv2)) {
296 type = 1;
297 }
298 } else if (!(s->options & SSL_OP_NO_SSLv3)) {
299 s->version = SSL3_VERSION;
300 /* type=2; */
301 s->state = SSL23_ST_SR_CLNT_HELLO_B;
302 } else if (!(s->options & SSL_OP_NO_SSLv2))
303 type = 1;
304
305 }
306 }
307 /* p[4] < 5 ... silly record length? */
308 else if ((p[0] == SSL3_RT_HANDSHAKE) &&
309 (p[1] == SSL3_VERSION_MAJOR) &&
310 (p[5] == SSL3_MT_CLIENT_HELLO) && ((p[3] == 0 && p[4] < 5)
311 || (p[9] >= p[1]))) {
312 /*
313 * SSLv3 or tls1 header
314 */
315
316 v[0] = p[1]; /* major version (= SSL3_VERSION_MAJOR) */
317 /*
318 * We must look at client_version inside the Client Hello message
319 * to get the correct minor version. However if we have only a
320 * pathologically small fragment of the Client Hello message, this
321 * would be difficult, and we'd have to read more records to find
322 * out. No known SSL 3.0 client fragments ClientHello like this,
323 * so we simply reject such connections to avoid protocol version
324 * downgrade attacks.
325 */
326 if (p[3] == 0 && p[4] < 6) {
327 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_TOO_SMALL);
328 goto err;
329 }
330 /*
331 * if major version number > 3 set minor to a value which will
332 * use the highest version 3 we support. If TLS 2.0 ever appears
333 * we will need to revise this....
334 */
335 if (p[9] > SSL3_VERSION_MAJOR)
336 v[1] = 0xff;
337 else
338 v[1] = p[10]; /* minor version according to client_version */
339 if (v[1] >= TLS1_VERSION_MINOR) {
340 if (!(s->options & SSL_OP_NO_TLSv1)) {
341 s->version = TLS1_VERSION;
342 type = 3;
343 } else if (!(s->options & SSL_OP_NO_SSLv3)) {
344 s->version = SSL3_VERSION;
345 type = 3;
346 }
347 } else {
348 /* client requests SSL 3.0 */
349 if (!(s->options & SSL_OP_NO_SSLv3)) {
350 s->version = SSL3_VERSION;
351 type = 3;
352 } else if (!(s->options & SSL_OP_NO_TLSv1)) {
353 /*
354 * we won't be able to use TLS of course, but this will
355 * send an appropriate alert
356 */
357 s->version = TLS1_VERSION;
358 type = 3;
359 }
360 }
361 } else if ((strncmp("GET ", (char *)p, 4) == 0) ||
362 (strncmp("POST ", (char *)p, 5) == 0) ||
363 (strncmp("HEAD ", (char *)p, 5) == 0) ||
364 (strncmp("PUT ", (char *)p, 4) == 0)) {
365 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_HTTP_REQUEST);
366 goto err;
367 } else if (strncmp("CONNECT", (char *)p, 7) == 0) {
368 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_HTTPS_PROXY_REQUEST);
369 goto err;
370 }
371 }
372 #ifdef OPENSSL_FIPS
373 if (FIPS_mode() && (s->version < TLS1_VERSION)) {
374 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
375 SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
376 goto err;
377 }
378 #endif
379
380 /* ensure that TLS_MAX_VERSION is up-to-date */
381 OPENSSL_assert(s->version <= TLS_MAX_VERSION);
382
383 if (s->state == SSL23_ST_SR_CLNT_HELLO_B) {
384 /*
385 * we have SSLv3/TLSv1 in an SSLv2 header (other cases skip this
386 * state)
387 */
388
389 type = 2;
390 p = s->packet;
391 v[0] = p[3]; /* == SSL3_VERSION_MAJOR */
392 v[1] = p[4];
393
394 /*-
395 * An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2
396 * header is sent directly on the wire, not wrapped as a TLS
397 * record. It's format is:
398 * Byte Content
399 * 0-1 msg_length
400 * 2 msg_type
401 * 3-4 version
402 * 5-6 cipher_spec_length
403 * 7-8 session_id_length
404 * 9-10 challenge_length
405 * ... ...
406 */
407 n = ((p[0] & 0x7f) << 8) | p[1];
408 if (n > (1024 * 4)) {
409 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_TOO_LARGE);
410 goto err;
411 }
412 if (n < 9) {
413 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
414 SSL_R_RECORD_LENGTH_MISMATCH);
415 goto err;
416 }
417
418 j = ssl23_read_bytes(s, n + 2);
419 /*
420 * We previously read 11 bytes, so if j > 0, we must have j == n+2 ==
421 * s->packet_length. We have at least 11 valid packet bytes.
422 */
423 if (j <= 0)
424 return (j);
425
426 ssl3_finish_mac(s, s->packet + 2, s->packet_length - 2);
427
428 /* CLIENT-HELLO */
429 if (s->msg_callback)
430 s->msg_callback(0, SSL2_VERSION, 0, s->packet + 2,
431 s->packet_length - 2, s, s->msg_callback_arg);
432
433 p = s->packet;
434 p += 5;
435 n2s(p, csl);
436 n2s(p, sil);
437 n2s(p, cl);
438 d = (unsigned char *)s->init_buf->data;
439 if ((csl + sil + cl + 11) != s->packet_length) {
440 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
441 SSL_R_RECORD_LENGTH_MISMATCH);
442 goto err;
443 }
444
445 /* record header: msg_type ... */
446 *(d++) = SSL3_MT_CLIENT_HELLO;
447 /* ... and length (actual value will be written later) */
448 d_len = d;
449 d += 3;
450
451 /* client_version */
452 *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */
453 *(d++) = v[1];
454
455 /* lets populate the random area */
456 /* get the challenge_length */
457 i = (cl > SSL3_RANDOM_SIZE) ? SSL3_RANDOM_SIZE : cl;
458 memset(d, 0, SSL3_RANDOM_SIZE);
459 memcpy(&(d[SSL3_RANDOM_SIZE - i]), &(p[csl + sil]), i);
460 d += SSL3_RANDOM_SIZE;
461
462 /* no session-id reuse */
463 *(d++) = 0;
464
465 /* ciphers */
466 j = 0;
467 dd = d;
468 d += 2;
469 for (i = 0; i < csl; i += 3) {
470 if (p[i] != 0)
471 continue;
472 *(d++) = p[i + 1];
473 *(d++) = p[i + 2];
474 j += 2;
475 }
476 s2n(j, dd);
477
478 /* COMPRESSION */
479 *(d++) = 1;
480 *(d++) = 0;
481
482 i = (d - (unsigned char *)s->init_buf->data) - 4;
483 l2n3((long)i, d_len);
484
485 /* get the data reused from the init_buf */
486 s->s3->tmp.reuse_message = 1;
487 s->s3->tmp.message_type = SSL3_MT_CLIENT_HELLO;
488 s->s3->tmp.message_size = i;
489 }
490
491 /* imaginary new state (for program structure): */
492 /* s->state = SSL23_SR_CLNT_HELLO_C */
493
494 if (type == 1) {
495 #ifdef OPENSSL_NO_SSL2
496 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNSUPPORTED_PROTOCOL);
497 goto err;
498 #else
499 /* we are talking sslv2 */
500 /*
501 * we need to clean up the SSLv3/TLSv1 setup and put in the sslv2
502 * stuff.
503 */
504
505 if (s->s2 == NULL) {
506 if (!ssl2_new(s))
507 goto err;
508 } else
509 ssl2_clear(s);
510
511 if (s->s3 != NULL)
512 ssl3_free(s);
513
514 if (!BUF_MEM_grow_clean(s->init_buf,
515 SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)) {
516 goto err;
517 }
518
519 s->state = SSL2_ST_GET_CLIENT_HELLO_A;
520 if (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3)
521 s->s2->ssl2_rollback = 0;
522 else
523 /*
524 * reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0
525 * (SSL 3.0 draft/RFC 2246, App. E.2)
526 */
527 s->s2->ssl2_rollback = 1;
528
529 /*
530 * setup the n bytes we have read so we get them from the sslv2
531 * buffer
532 */
533 s->rstate = SSL_ST_READ_HEADER;
534 s->packet_length = n;
535 s->packet = &(s->s2->rbuf[0]);
536 memcpy(s->packet, buf, n);
537 s->s2->rbuf_left = n;
538 s->s2->rbuf_offs = 0;
539
540 s->method = SSLv2_server_method();
541 s->handshake_func = s->method->ssl_accept;
542 #endif
543 }
544
545 if ((type == 2) || (type == 3)) {
546 /*
547 * we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style)
548 */
549 SSL_METHOD *new_method;
550 new_method = ssl23_get_server_method(s->version);
551 if (new_method == NULL) {
552 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNSUPPORTED_PROTOCOL);
553 goto err;
554 }
555 s->method = new_method;
556
557 if (!ssl_init_wbio_buffer(s, 1))
558 goto err;
559
560 /* we are in this state */
561 s->state = SSL3_ST_SR_CLNT_HELLO_A;
562
563 if (type == 3) {
564 /*
565 * put the 'n' bytes we have read into the input buffer for SSLv3
566 */
567 s->rstate = SSL_ST_READ_HEADER;
568 s->packet_length = n;
569 s->packet = &(s->s3->rbuf.buf[0]);
570 memcpy(s->packet, buf, n);
571 s->s3->rbuf.left = n;
572 s->s3->rbuf.offset = 0;
573 } else {
574 s->packet_length = 0;
575 s->s3->rbuf.left = 0;
576 s->s3->rbuf.offset = 0;
577 }
578 #if 0 /* ssl3_get_client_hello does this */
579 s->client_version = (v[0] << 8) | v[1];
580 #endif
581 s->handshake_func = s->method->ssl_accept;
582 }
583
584 if ((type < 1) || (type > 3)) {
585 /* bad, very bad */
586 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
587 goto err;
588 }
589 s->init_num = 0;
590
591 if (buf != buf_space)
592 OPENSSL_free(buf);
593 return (SSL_accept(s));
594 err:
595 if (buf != buf_space)
596 OPENSSL_free(buf);
597 return (-1);
598 }
599