1 /* $OpenBSD: s23_srvr.c,v 1.46 2015/10/25 15:49:04 doug Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
58 /* ====================================================================
59 * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved.
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
87 * 6. Redistributions of any form whatsoever must retain the following
89 * "This product includes software developed by the OpenSSL Project
90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 * ====================================================================
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).
114 #include "ssl_locl.h"
116 #include <openssl/buffer.h>
117 #include <openssl/evp.h>
118 #include <openssl/objects.h>
120 int ssl23_get_client_hello(SSL
*s
);
125 void (*cb
)(const SSL
*ssl
, int type
, int val
) = NULL
;
127 int new_state
, state
;
132 if (s
->info_callback
!= NULL
)
133 cb
= s
->info_callback
;
134 else if (s
->ctx
->info_callback
!= NULL
)
135 cb
= s
->ctx
->info_callback
;
138 if (!SSL_in_init(s
) || SSL_in_before(s
))
147 case SSL_ST_BEFORE
|SSL_ST_ACCEPT
:
148 case SSL_ST_OK
|SSL_ST_ACCEPT
:
152 cb(s
, SSL_CB_HANDSHAKE_START
, 1);
154 /* s->version=SSL3_VERSION; */
155 s
->type
= SSL_ST_ACCEPT
;
157 if (!ssl3_setup_init_buffer(s
)) {
161 if (!tls1_init_finished_mac(s
)) {
166 s
->state
= SSL23_ST_SR_CLNT_HELLO_A
;
167 s
->ctx
->stats
.sess_accept
++;
171 case SSL23_ST_SR_CLNT_HELLO_A
:
172 case SSL23_ST_SR_CLNT_HELLO_B
:
175 ret
= ssl23_get_client_hello(s
);
182 SSLerr(SSL_F_SSL23_ACCEPT
, SSL_R_UNKNOWN_STATE
);
188 if ((cb
!= NULL
) && (s
->state
!= state
)) {
189 new_state
= s
->state
;
191 cb(s
, SSL_CB_ACCEPT_LOOP
, 1);
192 s
->state
= new_state
;
199 cb(s
, SSL_CB_ACCEPT_EXIT
, ret
);
206 ssl23_get_client_hello(SSL
*s
)
210 * sizeof(buf) == 11, because we'll need to request this many bytes in
212 * We can detect SSL 3.0/TLS 1.0 Client Hellos ('type == 3') correctly
213 * only when the following is in a single record, which is not
214 * guaranteed by the protocol specification:
217 * 1/2 version > record header
220 * 6-8 length > Client Hello message
221 * 9/10 client_version /
223 unsigned char *p
, *d
, *d_len
, *dd
;
225 unsigned int csl
, sil
, cl
;
230 if (s
->state
== SSL23_ST_SR_CLNT_HELLO_A
) {
231 /* read the initial header */
234 if (!ssl3_setup_buffers(s
))
237 n
= ssl23_read_bytes(s
, sizeof buf
);
245 if ((p
[0] & 0x80) && (p
[2] == SSL2_MT_CLIENT_HELLO
)) {
249 if ((p
[3] == 0x00) && (p
[4] == 0x02)) {
250 /* SSLv2 support has been removed */
253 } else if (p
[3] == SSL3_VERSION_MAJOR
) {
258 if (p
[4] >= TLS1_VERSION_MINOR
) {
259 if (p
[4] >= TLS1_2_VERSION_MINOR
&&
260 !(s
->options
& SSL_OP_NO_TLSv1_2
)) {
261 s
->version
= TLS1_2_VERSION
;
262 s
->state
= SSL23_ST_SR_CLNT_HELLO_B
;
263 } else if (p
[4] >= TLS1_1_VERSION_MINOR
&&
264 !(s
->options
& SSL_OP_NO_TLSv1_1
)) {
265 s
->version
= TLS1_1_VERSION
;
266 /* type=2; */ /* done later to survive restarts */
267 s
->state
= SSL23_ST_SR_CLNT_HELLO_B
;
268 } else if (!(s
->options
& SSL_OP_NO_TLSv1
)) {
269 s
->version
= TLS1_VERSION
;
270 /* type=2; */ /* done later to survive restarts */
271 s
->state
= SSL23_ST_SR_CLNT_HELLO_B
;
276 /* SSLv3 support has been removed */
280 } else if ((p
[0] == SSL3_RT_HANDSHAKE
) &&
281 (p
[1] == SSL3_VERSION_MAJOR
) &&
282 (p
[5] == SSL3_MT_CLIENT_HELLO
) &&
283 ((p
[3] == 0 && p
[4] < 5 /* silly record length? */) ||
286 * SSLv3 or tls1 header
289 v
[0] = p
[1]; /* major version (= SSL3_VERSION_MAJOR) */
290 /* We must look at client_version inside the Client Hello message
291 * to get the correct minor version.
292 * However if we have only a pathologically small fragment of the
293 * Client Hello message, this would be difficult, and we'd have
294 * to read more records to find out.
295 * No known SSL 3.0 client fragments ClientHello like this,
296 * so we simply reject such connections to avoid
297 * protocol version downgrade attacks. */
298 if (p
[3] == 0 && p
[4] < 6) {
299 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO
,
300 SSL_R_RECORD_TOO_SMALL
);
303 /* if major version number > 3 set minor to a value
304 * which will use the highest version 3 we support.
305 * If TLS 2.0 ever appears we will need to revise
308 if (p
[9] > SSL3_VERSION_MAJOR
)
311 v
[1] = p
[10]; /* minor version according to client_version */
312 if (v
[1] >= TLS1_VERSION_MINOR
) {
313 if (v
[1] >= TLS1_2_VERSION_MINOR
&&
314 !(s
->options
& SSL_OP_NO_TLSv1_2
)) {
315 s
->version
= TLS1_2_VERSION
;
317 } else if (v
[1] >= TLS1_1_VERSION_MINOR
&&
318 !(s
->options
& SSL_OP_NO_TLSv1_1
)) {
319 s
->version
= TLS1_1_VERSION
;
321 } else if (!(s
->options
& SSL_OP_NO_TLSv1
)) {
322 s
->version
= TLS1_VERSION
;
329 if (!(s
->options
& SSL_OP_NO_TLSv1
)) {
330 /* we won't be able to use TLS of course,
331 * but this will send an appropriate alert */
332 s
->version
= TLS1_VERSION
;
339 else if ((strncmp("GET ", (char *)p
, 4) == 0) ||
340 (strncmp("POST ",(char *)p
, 5) == 0) ||
341 (strncmp("HEAD ",(char *)p
, 5) == 0) ||
342 (strncmp("PUT ", (char *)p
, 4) == 0)) {
343 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO
, SSL_R_HTTP_REQUEST
);
345 } else if (strncmp("CONNECT", (char *)p
, 7) == 0) {
346 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO
, SSL_R_HTTPS_PROXY_REQUEST
);
351 if (s
->state
== SSL23_ST_SR_CLNT_HELLO_B
) {
352 /* we have SSLv3/TLSv1 in an SSLv2 header
353 * (other cases skip this state) */
356 * Limit the support of "backward compatible" headers
357 * only to "backward" versions of TLS. If we have moved
358 * on to modernity, just say no.
360 if (s
->options
& SSL_OP_NO_TLSv1
)
365 v
[0] = p
[3]; /* == SSL3_VERSION_MAJOR */
368 /* An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2
369 * header is sent directly on the wire, not wrapped as a TLS
370 * record. It's format is:
375 * 5-6 cipher_spec_length
376 * 7-8 session_id_length
377 * 9-10 challenge_length
380 n
= ((p
[0] & 0x7f) << 8) | p
[1];
381 if (n
> (1024 * 4)) {
382 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO
, SSL_R_RECORD_TOO_LARGE
);
386 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO
,
387 SSL_R_RECORD_LENGTH_MISMATCH
);
391 j
= ssl23_read_bytes(s
, n
+ 2);
395 tls1_finish_mac(s
, s
->packet
+ 2, s
->packet_length
- 2);
397 s
->msg_callback(0, SSL2_VERSION
, 0, s
->packet
+ 2,
398 s
->packet_length
- 2, s
, s
->msg_callback_arg
);
405 d
= (unsigned char *)s
->init_buf
->data
;
406 if ((csl
+ sil
+ cl
+ 11) != s
->packet_length
) {
408 * We can't have TLS extensions in SSL 2.0 format
409 * Client Hello, can we ? Error condition should be
412 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO
,
413 SSL_R_RECORD_LENGTH_MISMATCH
);
417 /* record header: msg_type ... */
418 *(d
++) = SSL3_MT_CLIENT_HELLO
;
419 /* ... and length (actual value will be written later) */
424 *(d
++) = SSL3_VERSION_MAJOR
; /* == v[0] */
427 /* lets populate the random area */
428 /* get the challenge_length */
429 i
= (cl
> SSL3_RANDOM_SIZE
) ? SSL3_RANDOM_SIZE
: cl
;
430 memset(d
, 0, SSL3_RANDOM_SIZE
);
431 memcpy(&(d
[SSL3_RANDOM_SIZE
- i
]), &(p
[csl
+ sil
]), i
);
432 d
+= SSL3_RANDOM_SIZE
;
434 /* no session-id reuse */
441 for (i
= 0; i
< csl
; i
+= 3) {
450 /* add in (no) COMPRESSION */
454 i
= (d
- (unsigned char *)s
->init_buf
->data
) - 4;
455 l2n3((long)i
, d_len
);
457 /* get the data reused from the init_buf */
458 s
->s3
->tmp
.reuse_message
= 1;
459 s
->s3
->tmp
.message_type
= SSL3_MT_CLIENT_HELLO
;
460 s
->s3
->tmp
.message_size
= i
;
463 /* imaginary new state (for program structure): */
464 /* s->state = SSL23_SR_CLNT_HELLO_C */
466 if (type
== 2 || type
== 3) {
467 /* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */
469 if (!ssl_init_wbio_buffer(s
, 1))
472 /* we are in this state */
473 s
->state
= SSL3_ST_SR_CLNT_HELLO_A
;
476 /* put the 'n' bytes we have read into the input buffer
478 s
->rstate
= SSL_ST_READ_HEADER
;
479 s
->packet_length
= n
;
480 if (s
->s3
->rbuf
.buf
== NULL
)
481 if (!ssl3_setup_read_buffer(s
))
484 s
->packet
= &(s
->s3
->rbuf
.buf
[0]);
485 memcpy(s
->packet
, buf
, n
);
486 s
->s3
->rbuf
.left
= n
;
487 s
->s3
->rbuf
.offset
= 0;
489 s
->packet_length
= 0;
490 s
->s3
->rbuf
.left
= 0;
491 s
->s3
->rbuf
.offset
= 0;
493 if (s
->version
== TLS1_2_VERSION
)
494 s
->method
= TLSv1_2_server_method();
495 else if (s
->version
== TLS1_1_VERSION
)
496 s
->method
= TLSv1_1_server_method();
497 else if (s
->version
== TLS1_VERSION
)
498 s
->method
= TLSv1_server_method();
501 s
->handshake_func
= s
->method
->ssl_accept
;
504 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO
, SSL_R_UNKNOWN_PROTOCOL
);
509 return (SSL_accept(s
));
512 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO
, SSL_R_UNSUPPORTED_PROTOCOL
);