1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.]
56  */
57 /* ====================================================================
58  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
59  *
60  * Redistribution and use in source and binary forms, with or without
61  * modification, are permitted provided that the following conditions
62  * are met:
63  *
64  * 1. Redistributions of source code must retain the above copyright
65  *    notice, this list of conditions and the following disclaimer.
66  *
67  * 2. Redistributions in binary form must reproduce the above copyright
68  *    notice, this list of conditions and the following disclaimer in
69  *    the documentation and/or other materials provided with the
70  *    distribution.
71  *
72  * 3. All advertising materials mentioning features or use of this
73  *    software must display the following acknowledgment:
74  *    "This product includes software developed by the OpenSSL Project
75  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
76  *
77  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
78  *    endorse or promote products derived from this software without
79  *    prior written permission. For written permission, please contact
80  *    openssl-core@openssl.org.
81  *
82  * 5. Products derived from this software may not be called "OpenSSL"
83  *    nor may "OpenSSL" appear in their names without prior written
84  *    permission of the OpenSSL Project.
85  *
86  * 6. Redistributions of any form whatsoever must retain the following
87  *    acknowledgment:
88  *    "This product includes software developed by the OpenSSL Project
89  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
90  *
91  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
92  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
93  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
94  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
95  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
96  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
97  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
98  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
99  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
100  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
101  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
102  * OF THE POSSIBILITY OF SUCH DAMAGE.
103  * ====================================================================
104  *
105  * This product includes cryptographic software written by Eric Young
106  * (eay@cryptsoft.com).  This product includes software written by Tim
107  * Hudson (tjh@cryptsoft.com). */
108 /* ====================================================================
109  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
110  * ECC cipher suite support in OpenSSL originally developed by
111  * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project. */
112 
113 #include <openssl/ssl.h>
114 
115 #include <assert.h>
116 #include <limits.h>
117 #include <string.h>
118 
119 #include <openssl/buf.h>
120 #include <openssl/bytestring.h>
121 #include <openssl/err.h>
122 #include <openssl/evp.h>
123 #include <openssl/mem.h>
124 #include <openssl/md5.h>
125 #include <openssl/nid.h>
126 #include <openssl/rand.h>
127 #include <openssl/sha.h>
128 
129 #include "../crypto/internal.h"
130 #include "internal.h"
131 
132 
ssl_handshake_new(SSL * ssl)133 SSL_HANDSHAKE *ssl_handshake_new(SSL *ssl) {
134   SSL_HANDSHAKE *hs = OPENSSL_malloc(sizeof(SSL_HANDSHAKE));
135   if (hs == NULL) {
136     OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
137     return NULL;
138   }
139   OPENSSL_memset(hs, 0, sizeof(SSL_HANDSHAKE));
140   hs->ssl = ssl;
141   hs->wait = ssl_hs_ok;
142   hs->state = SSL_ST_INIT;
143   if (!SSL_TRANSCRIPT_init(&hs->transcript)) {
144     ssl_handshake_free(hs);
145     return NULL;
146   }
147   return hs;
148 }
149 
ssl_handshake_free(SSL_HANDSHAKE * hs)150 void ssl_handshake_free(SSL_HANDSHAKE *hs) {
151   if (hs == NULL) {
152     return;
153   }
154 
155   OPENSSL_cleanse(hs->secret, sizeof(hs->secret));
156   OPENSSL_cleanse(hs->early_traffic_secret, sizeof(hs->early_traffic_secret));
157   OPENSSL_cleanse(hs->client_handshake_secret,
158                   sizeof(hs->client_handshake_secret));
159   OPENSSL_cleanse(hs->server_handshake_secret,
160                   sizeof(hs->server_handshake_secret));
161   OPENSSL_cleanse(hs->client_traffic_secret_0,
162                   sizeof(hs->client_traffic_secret_0));
163   OPENSSL_cleanse(hs->server_traffic_secret_0,
164                   sizeof(hs->server_traffic_secret_0));
165   SSL_ECDH_CTX_cleanup(&hs->ecdh_ctx);
166   SSL_TRANSCRIPT_cleanup(&hs->transcript);
167   OPENSSL_free(hs->cookie);
168   OPENSSL_free(hs->key_share_bytes);
169   OPENSSL_free(hs->public_key);
170   SSL_SESSION_free(hs->new_session);
171   OPENSSL_free(hs->peer_sigalgs);
172   OPENSSL_free(hs->peer_supported_group_list);
173   OPENSSL_free(hs->peer_key);
174   OPENSSL_free(hs->server_params);
175   OPENSSL_free(hs->peer_psk_identity_hint);
176   sk_CRYPTO_BUFFER_pop_free(hs->ca_names, CRYPTO_BUFFER_free);
177   hs->ssl->ctx->x509_method->hs_flush_cached_ca_names(hs);
178   OPENSSL_free(hs->certificate_types);
179 
180   if (hs->key_block != NULL) {
181     OPENSSL_cleanse(hs->key_block, hs->key_block_len);
182     OPENSSL_free(hs->key_block);
183   }
184 
185   OPENSSL_free(hs->hostname);
186   EVP_PKEY_free(hs->peer_pubkey);
187   OPENSSL_free(hs);
188 }
189 
ssl_check_message_type(SSL * ssl,int type)190 int ssl_check_message_type(SSL *ssl, int type) {
191   if (ssl->s3->tmp.message_type != type) {
192     ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
193     OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
194     ERR_add_error_dataf("got type %d, wanted type %d",
195                         ssl->s3->tmp.message_type, type);
196     return 0;
197   }
198 
199   return 1;
200 }
201 
add_record_to_flight(SSL * ssl,uint8_t type,const uint8_t * in,size_t in_len)202 static int add_record_to_flight(SSL *ssl, uint8_t type, const uint8_t *in,
203                                 size_t in_len) {
204   /* We'll never add a flight while in the process of writing it out. */
205   assert(ssl->s3->pending_flight_offset == 0);
206 
207   if (ssl->s3->pending_flight == NULL) {
208     ssl->s3->pending_flight = BUF_MEM_new();
209     if (ssl->s3->pending_flight == NULL) {
210       return 0;
211     }
212   }
213 
214   size_t max_out = in_len + SSL_max_seal_overhead(ssl);
215   size_t new_cap = ssl->s3->pending_flight->length + max_out;
216   if (max_out < in_len || new_cap < max_out) {
217     OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
218     return 0;
219   }
220 
221   size_t len;
222   if (!BUF_MEM_reserve(ssl->s3->pending_flight, new_cap) ||
223       !tls_seal_record(ssl, (uint8_t *)ssl->s3->pending_flight->data +
224                                 ssl->s3->pending_flight->length,
225                        &len, max_out, type, in, in_len)) {
226     return 0;
227   }
228 
229   ssl->s3->pending_flight->length += len;
230   return 1;
231 }
232 
ssl3_init_message(SSL * ssl,CBB * cbb,CBB * body,uint8_t type)233 int ssl3_init_message(SSL *ssl, CBB *cbb, CBB *body, uint8_t type) {
234   /* Pick a modest size hint to save most of the |realloc| calls. */
235   if (!CBB_init(cbb, 64) ||
236       !CBB_add_u8(cbb, type) ||
237       !CBB_add_u24_length_prefixed(cbb, body)) {
238     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
239     CBB_cleanup(cbb);
240     return 0;
241   }
242 
243   return 1;
244 }
245 
ssl3_finish_message(SSL * ssl,CBB * cbb,uint8_t ** out_msg,size_t * out_len)246 int ssl3_finish_message(SSL *ssl, CBB *cbb, uint8_t **out_msg,
247                         size_t *out_len) {
248   if (!CBB_finish(cbb, out_msg, out_len)) {
249     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
250     return 0;
251   }
252 
253   return 1;
254 }
255 
ssl3_add_message(SSL * ssl,uint8_t * msg,size_t len)256 int ssl3_add_message(SSL *ssl, uint8_t *msg, size_t len) {
257   /* Add the message to the current flight, splitting into several records if
258    * needed. */
259   int ret = 0;
260   size_t added = 0;
261   do {
262     size_t todo = len - added;
263     if (todo > ssl->max_send_fragment) {
264       todo = ssl->max_send_fragment;
265     }
266 
267     if (!add_record_to_flight(ssl, SSL3_RT_HANDSHAKE, msg + added, todo)) {
268       goto err;
269     }
270     added += todo;
271   } while (added < len);
272 
273   ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_HANDSHAKE, msg, len);
274   /* TODO(svaldez): Move this up a layer to fix abstraction for SSL_TRANSCRIPT
275    * on hs. */
276   if (ssl->s3->hs != NULL &&
277       !SSL_TRANSCRIPT_update(&ssl->s3->hs->transcript, msg, len)) {
278     goto err;
279   }
280   ret = 1;
281 
282 err:
283   OPENSSL_free(msg);
284   return ret;
285 }
286 
ssl3_add_change_cipher_spec(SSL * ssl)287 int ssl3_add_change_cipher_spec(SSL *ssl) {
288   static const uint8_t kChangeCipherSpec[1] = {SSL3_MT_CCS};
289 
290   if (!add_record_to_flight(ssl, SSL3_RT_CHANGE_CIPHER_SPEC, kChangeCipherSpec,
291                             sizeof(kChangeCipherSpec))) {
292     return 0;
293   }
294 
295   ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_CHANGE_CIPHER_SPEC,
296                       kChangeCipherSpec, sizeof(kChangeCipherSpec));
297   return 1;
298 }
299 
ssl3_add_alert(SSL * ssl,uint8_t level,uint8_t desc)300 int ssl3_add_alert(SSL *ssl, uint8_t level, uint8_t desc) {
301   uint8_t alert[2] = {level, desc};
302   if (!add_record_to_flight(ssl, SSL3_RT_ALERT, alert, sizeof(alert))) {
303     return 0;
304   }
305 
306   ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_ALERT, alert, sizeof(alert));
307   ssl_do_info_callback(ssl, SSL_CB_WRITE_ALERT, ((int)level << 8) | desc);
308   return 1;
309 }
310 
ssl_add_message_cbb(SSL * ssl,CBB * cbb)311 int ssl_add_message_cbb(SSL *ssl, CBB *cbb) {
312   uint8_t *msg;
313   size_t len;
314   if (!ssl->method->finish_message(ssl, cbb, &msg, &len) ||
315       !ssl->method->add_message(ssl, msg, len)) {
316     return 0;
317   }
318 
319   return 1;
320 }
321 
ssl3_flush_flight(SSL * ssl)322 int ssl3_flush_flight(SSL *ssl) {
323   if (ssl->s3->pending_flight == NULL) {
324     return 1;
325   }
326 
327   if (ssl->s3->pending_flight->length > 0xffffffff ||
328       ssl->s3->pending_flight->length > INT_MAX) {
329     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
330     return -1;
331   }
332 
333   /* The handshake flight buffer is mutually exclusive with application data.
334    *
335    * TODO(davidben): This will not be true when closure alerts use this. */
336   if (ssl_write_buffer_is_pending(ssl)) {
337     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
338     return -1;
339   }
340 
341   /* Write the pending flight. */
342   while (ssl->s3->pending_flight_offset < ssl->s3->pending_flight->length) {
343     int ret = BIO_write(
344         ssl->wbio,
345         ssl->s3->pending_flight->data + ssl->s3->pending_flight_offset,
346         ssl->s3->pending_flight->length - ssl->s3->pending_flight_offset);
347     if (ret <= 0) {
348       ssl->rwstate = SSL_WRITING;
349       return ret;
350     }
351 
352     ssl->s3->pending_flight_offset += ret;
353   }
354 
355   if (BIO_flush(ssl->wbio) <= 0) {
356     ssl->rwstate = SSL_WRITING;
357     return -1;
358   }
359 
360   BUF_MEM_free(ssl->s3->pending_flight);
361   ssl->s3->pending_flight = NULL;
362   ssl->s3->pending_flight_offset = 0;
363   return 1;
364 }
365 
ssl3_send_finished(SSL_HANDSHAKE * hs)366 int ssl3_send_finished(SSL_HANDSHAKE *hs) {
367   SSL *const ssl = hs->ssl;
368   const SSL_SESSION *session = SSL_get_session(ssl);
369 
370   uint8_t finished[EVP_MAX_MD_SIZE];
371   size_t finished_len;
372   if (!SSL_TRANSCRIPT_finish_mac(&hs->transcript, finished, &finished_len,
373                                  session, ssl->server,
374                                  ssl3_protocol_version(ssl))) {
375     return 0;
376   }
377 
378   /* Log the master secret, if logging is enabled. */
379   if (!ssl_log_secret(ssl, "CLIENT_RANDOM",
380                       session->master_key,
381                       session->master_key_length)) {
382     return 0;
383   }
384 
385   /* Copy the Finished so we can use it for renegotiation checks. */
386   if (ssl->version != SSL3_VERSION) {
387     if (finished_len > sizeof(ssl->s3->previous_client_finished) ||
388         finished_len > sizeof(ssl->s3->previous_server_finished)) {
389       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
390       return -1;
391     }
392 
393     if (ssl->server) {
394       OPENSSL_memcpy(ssl->s3->previous_server_finished, finished, finished_len);
395       ssl->s3->previous_server_finished_len = finished_len;
396     } else {
397       OPENSSL_memcpy(ssl->s3->previous_client_finished, finished, finished_len);
398       ssl->s3->previous_client_finished_len = finished_len;
399     }
400   }
401 
402   CBB cbb, body;
403   if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_FINISHED) ||
404       !CBB_add_bytes(&body, finished, finished_len) ||
405       !ssl_add_message_cbb(ssl, &cbb)) {
406     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
407     CBB_cleanup(&cbb);
408     return -1;
409   }
410 
411   return 1;
412 }
413 
ssl3_get_finished(SSL_HANDSHAKE * hs)414 int ssl3_get_finished(SSL_HANDSHAKE *hs) {
415   SSL *const ssl = hs->ssl;
416   int ret = ssl->method->ssl_get_message(ssl);
417   if (ret <= 0) {
418     return ret;
419   }
420 
421   if (!ssl_check_message_type(ssl, SSL3_MT_FINISHED)) {
422     return -1;
423   }
424 
425   /* Snapshot the finished hash before incorporating the new message. */
426   uint8_t finished[EVP_MAX_MD_SIZE];
427   size_t finished_len;
428   if (!SSL_TRANSCRIPT_finish_mac(&hs->transcript, finished, &finished_len,
429                                  SSL_get_session(ssl), !ssl->server,
430                                  ssl3_protocol_version(ssl)) ||
431       !ssl_hash_current_message(hs)) {
432     return -1;
433   }
434 
435   int finished_ok = ssl->init_num == finished_len &&
436                     CRYPTO_memcmp(ssl->init_msg, finished, finished_len) == 0;
437 #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
438   finished_ok = 1;
439 #endif
440   if (!finished_ok) {
441     ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
442     OPENSSL_PUT_ERROR(SSL, SSL_R_DIGEST_CHECK_FAILED);
443     return -1;
444   }
445 
446   /* Copy the Finished so we can use it for renegotiation checks. */
447   if (ssl->version != SSL3_VERSION) {
448     if (finished_len > sizeof(ssl->s3->previous_client_finished) ||
449         finished_len > sizeof(ssl->s3->previous_server_finished)) {
450       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
451       return -1;
452     }
453 
454     if (ssl->server) {
455       OPENSSL_memcpy(ssl->s3->previous_client_finished, finished, finished_len);
456       ssl->s3->previous_client_finished_len = finished_len;
457     } else {
458       OPENSSL_memcpy(ssl->s3->previous_server_finished, finished, finished_len);
459       ssl->s3->previous_server_finished_len = finished_len;
460     }
461   }
462 
463   return 1;
464 }
465 
ssl3_output_cert_chain(SSL * ssl)466 int ssl3_output_cert_chain(SSL *ssl) {
467   CBB cbb, body;
468   if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_CERTIFICATE) ||
469       !ssl_add_cert_chain(ssl, &body) ||
470       !ssl_add_message_cbb(ssl, &cbb)) {
471     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
472     CBB_cleanup(&cbb);
473     return 0;
474   }
475 
476   return 1;
477 }
478 
ssl_max_handshake_message_len(const SSL * ssl)479 size_t ssl_max_handshake_message_len(const SSL *ssl) {
480   /* kMaxMessageLen is the default maximum message size for handshakes which do
481    * not accept peer certificate chains. */
482   static const size_t kMaxMessageLen = 16384;
483 
484   if (SSL_in_init(ssl)) {
485     if ((!ssl->server || (ssl->verify_mode & SSL_VERIFY_PEER)) &&
486         kMaxMessageLen < ssl->max_cert_list) {
487       return ssl->max_cert_list;
488     }
489     return kMaxMessageLen;
490   }
491 
492   if (ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
493     /* In TLS 1.2 and below, the largest acceptable post-handshake message is
494      * a HelloRequest. */
495     return 0;
496   }
497 
498   if (ssl->server) {
499     /* The largest acceptable post-handshake message for a server is a
500      * KeyUpdate. We will never initiate post-handshake auth. */
501     return 1;
502   }
503 
504   /* Clients must accept NewSessionTicket and CertificateRequest, so allow the
505    * default size. */
506   return kMaxMessageLen;
507 }
508 
extend_handshake_buffer(SSL * ssl,size_t length)509 static int extend_handshake_buffer(SSL *ssl, size_t length) {
510   if (!BUF_MEM_reserve(ssl->init_buf, length)) {
511     return -1;
512   }
513   while (ssl->init_buf->length < length) {
514     int ret = ssl3_read_handshake_bytes(
515         ssl, (uint8_t *)ssl->init_buf->data + ssl->init_buf->length,
516         length - ssl->init_buf->length);
517     if (ret <= 0) {
518       return ret;
519     }
520     ssl->init_buf->length += (size_t)ret;
521   }
522   return 1;
523 }
524 
read_v2_client_hello(SSL * ssl)525 static int read_v2_client_hello(SSL *ssl) {
526   /* Read the first 5 bytes, the size of the TLS record header. This is
527    * sufficient to detect a V2ClientHello and ensures that we never read beyond
528    * the first record. */
529   int ret = ssl_read_buffer_extend_to(ssl, SSL3_RT_HEADER_LENGTH);
530   if (ret <= 0) {
531     return ret;
532   }
533   const uint8_t *p = ssl_read_buffer(ssl);
534 
535   /* Some dedicated error codes for protocol mixups should the application wish
536    * to interpret them differently. (These do not overlap with ClientHello or
537    * V2ClientHello.) */
538   if (strncmp("GET ", (const char *)p, 4) == 0 ||
539       strncmp("POST ", (const char *)p, 5) == 0 ||
540       strncmp("HEAD ", (const char *)p, 5) == 0 ||
541       strncmp("PUT ", (const char *)p, 4) == 0) {
542     OPENSSL_PUT_ERROR(SSL, SSL_R_HTTP_REQUEST);
543     return -1;
544   }
545   if (strncmp("CONNE", (const char *)p, 5) == 0) {
546     OPENSSL_PUT_ERROR(SSL, SSL_R_HTTPS_PROXY_REQUEST);
547     return -1;
548   }
549 
550   if ((p[0] & 0x80) == 0 || p[2] != SSL2_MT_CLIENT_HELLO ||
551       p[3] != SSL3_VERSION_MAJOR) {
552     /* Not a V2ClientHello. */
553     return 1;
554   }
555 
556   /* Determine the length of the V2ClientHello. */
557   size_t msg_length = ((p[0] & 0x7f) << 8) | p[1];
558   if (msg_length > (1024 * 4)) {
559     OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE);
560     return -1;
561   }
562   if (msg_length < SSL3_RT_HEADER_LENGTH - 2) {
563     /* Reject lengths that are too short early. We have already read
564      * |SSL3_RT_HEADER_LENGTH| bytes, so we should not attempt to process an
565      * (invalid) V2ClientHello which would be shorter than that. */
566     OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_LENGTH_MISMATCH);
567     return -1;
568   }
569 
570   /* Read the remainder of the V2ClientHello. */
571   ret = ssl_read_buffer_extend_to(ssl, 2 + msg_length);
572   if (ret <= 0) {
573     return ret;
574   }
575 
576   CBS v2_client_hello;
577   CBS_init(&v2_client_hello, ssl_read_buffer(ssl) + 2, msg_length);
578 
579   /* The V2ClientHello without the length is incorporated into the handshake
580    * hash. This is only ever called at the start of the handshake, so hs is
581    * guaranteed to be non-NULL. */
582   if (!SSL_TRANSCRIPT_update(&ssl->s3->hs->transcript,
583                              CBS_data(&v2_client_hello),
584                              CBS_len(&v2_client_hello))) {
585     return -1;
586   }
587 
588   ssl_do_msg_callback(ssl, 0 /* read */, 0 /* V2ClientHello */,
589                       CBS_data(&v2_client_hello), CBS_len(&v2_client_hello));
590 
591   uint8_t msg_type;
592   uint16_t version, cipher_spec_length, session_id_length, challenge_length;
593   CBS cipher_specs, session_id, challenge;
594   if (!CBS_get_u8(&v2_client_hello, &msg_type) ||
595       !CBS_get_u16(&v2_client_hello, &version) ||
596       !CBS_get_u16(&v2_client_hello, &cipher_spec_length) ||
597       !CBS_get_u16(&v2_client_hello, &session_id_length) ||
598       !CBS_get_u16(&v2_client_hello, &challenge_length) ||
599       !CBS_get_bytes(&v2_client_hello, &cipher_specs, cipher_spec_length) ||
600       !CBS_get_bytes(&v2_client_hello, &session_id, session_id_length) ||
601       !CBS_get_bytes(&v2_client_hello, &challenge, challenge_length) ||
602       CBS_len(&v2_client_hello) != 0) {
603     OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
604     return -1;
605   }
606 
607   /* msg_type has already been checked. */
608   assert(msg_type == SSL2_MT_CLIENT_HELLO);
609 
610   /* The client_random is the V2ClientHello challenge. Truncate or
611    * left-pad with zeros as needed. */
612   size_t rand_len = CBS_len(&challenge);
613   if (rand_len > SSL3_RANDOM_SIZE) {
614     rand_len = SSL3_RANDOM_SIZE;
615   }
616   uint8_t random[SSL3_RANDOM_SIZE];
617   OPENSSL_memset(random, 0, SSL3_RANDOM_SIZE);
618   OPENSSL_memcpy(random + (SSL3_RANDOM_SIZE - rand_len), CBS_data(&challenge),
619                  rand_len);
620 
621   /* Write out an equivalent SSLv3 ClientHello. */
622   size_t max_v3_client_hello = SSL3_HM_HEADER_LENGTH + 2 /* version */ +
623                                SSL3_RANDOM_SIZE + 1 /* session ID length */ +
624                                2 /* cipher list length */ +
625                                CBS_len(&cipher_specs) / 3 * 2 +
626                                1 /* compression length */ + 1 /* compression */;
627   CBB client_hello, hello_body, cipher_suites;
628   CBB_zero(&client_hello);
629   if (!BUF_MEM_reserve(ssl->init_buf, max_v3_client_hello) ||
630       !CBB_init_fixed(&client_hello, (uint8_t *)ssl->init_buf->data,
631                       ssl->init_buf->max) ||
632       !CBB_add_u8(&client_hello, SSL3_MT_CLIENT_HELLO) ||
633       !CBB_add_u24_length_prefixed(&client_hello, &hello_body) ||
634       !CBB_add_u16(&hello_body, version) ||
635       !CBB_add_bytes(&hello_body, random, SSL3_RANDOM_SIZE) ||
636       /* No session id. */
637       !CBB_add_u8(&hello_body, 0) ||
638       !CBB_add_u16_length_prefixed(&hello_body, &cipher_suites)) {
639     CBB_cleanup(&client_hello);
640     OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
641     return -1;
642   }
643 
644   /* Copy the cipher suites. */
645   while (CBS_len(&cipher_specs) > 0) {
646     uint32_t cipher_spec;
647     if (!CBS_get_u24(&cipher_specs, &cipher_spec)) {
648       CBB_cleanup(&client_hello);
649       OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
650       return -1;
651     }
652 
653     /* Skip SSLv2 ciphers. */
654     if ((cipher_spec & 0xff0000) != 0) {
655       continue;
656     }
657     if (!CBB_add_u16(&cipher_suites, cipher_spec)) {
658       CBB_cleanup(&client_hello);
659       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
660       return -1;
661     }
662   }
663 
664   /* Add the null compression scheme and finish. */
665   if (!CBB_add_u8(&hello_body, 1) || !CBB_add_u8(&hello_body, 0) ||
666       !CBB_finish(&client_hello, NULL, &ssl->init_buf->length)) {
667     CBB_cleanup(&client_hello);
668     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
669     return -1;
670   }
671 
672   /* Consume and discard the V2ClientHello. */
673   ssl_read_buffer_consume(ssl, 2 + msg_length);
674   ssl_read_buffer_discard(ssl);
675 
676   ssl->s3->is_v2_hello = 1;
677   /* This is the first message, so hs must be non-NULL. */
678   ssl->s3->hs->v2_clienthello = 1;
679   return 1;
680 }
681 
ssl3_get_message(SSL * ssl)682 int ssl3_get_message(SSL *ssl) {
683   /* Re-create the handshake buffer if needed. */
684   if (ssl->init_buf == NULL) {
685     ssl->init_buf = BUF_MEM_new();
686     if (ssl->init_buf == NULL) {
687       return -1;
688     }
689   }
690 
691   if (ssl->server && !ssl->s3->v2_hello_done) {
692     /* Bypass the record layer for the first message to handle V2ClientHello. */
693     int ret = read_v2_client_hello(ssl);
694     if (ret <= 0) {
695       return ret;
696     }
697     ssl->s3->v2_hello_done = 1;
698   }
699 
700   if (ssl->s3->tmp.reuse_message) {
701     /* There must be a current message. */
702     assert(ssl->init_msg != NULL);
703     ssl->s3->tmp.reuse_message = 0;
704   } else {
705     ssl3_release_current_message(ssl, 0 /* don't free buffer */);
706   }
707 
708   /* Read the message header, if we haven't yet. */
709   int ret = extend_handshake_buffer(ssl, SSL3_HM_HEADER_LENGTH);
710   if (ret <= 0) {
711     return ret;
712   }
713 
714   /* Parse out the length. Cap it so the peer cannot force us to buffer up to
715    * 2^24 bytes. */
716   const uint8_t *p = (uint8_t *)ssl->init_buf->data;
717   size_t msg_len = (((uint32_t)p[1]) << 16) | (((uint32_t)p[2]) << 8) | p[3];
718   if (msg_len > ssl_max_handshake_message_len(ssl)) {
719     ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
720     OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESSIVE_MESSAGE_SIZE);
721     return -1;
722   }
723 
724   /* Read the message body, if we haven't yet. */
725   ret = extend_handshake_buffer(ssl, SSL3_HM_HEADER_LENGTH + msg_len);
726   if (ret <= 0) {
727     return ret;
728   }
729 
730   /* We have now received a complete message. */
731   ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_HANDSHAKE, ssl->init_buf->data,
732                       ssl->init_buf->length);
733 
734   ssl->s3->tmp.message_type = ((const uint8_t *)ssl->init_buf->data)[0];
735   ssl->init_msg = (uint8_t*)ssl->init_buf->data + SSL3_HM_HEADER_LENGTH;
736   ssl->init_num = ssl->init_buf->length - SSL3_HM_HEADER_LENGTH;
737   return 1;
738 }
739 
ssl3_get_current_message(const SSL * ssl,CBS * out)740 void ssl3_get_current_message(const SSL *ssl, CBS *out) {
741   CBS_init(out, (uint8_t *)ssl->init_buf->data, ssl->init_buf->length);
742 }
743 
ssl_hash_current_message(SSL_HANDSHAKE * hs)744 int ssl_hash_current_message(SSL_HANDSHAKE *hs) {
745   /* V2ClientHellos are hashed implicitly. */
746   if (hs->ssl->s3->is_v2_hello) {
747     return 1;
748   }
749 
750   CBS cbs;
751   hs->ssl->method->get_current_message(hs->ssl, &cbs);
752   return SSL_TRANSCRIPT_update(&hs->transcript, CBS_data(&cbs), CBS_len(&cbs));
753 }
754 
ssl3_release_current_message(SSL * ssl,int free_buffer)755 void ssl3_release_current_message(SSL *ssl, int free_buffer) {
756   if (ssl->init_msg != NULL) {
757     /* |init_buf| never contains data beyond the current message. */
758     assert(SSL3_HM_HEADER_LENGTH + ssl->init_num == ssl->init_buf->length);
759 
760     /* Clear the current message. */
761     ssl->init_msg = NULL;
762     ssl->init_num = 0;
763     ssl->init_buf->length = 0;
764     ssl->s3->is_v2_hello = 0;
765   }
766 
767   if (free_buffer) {
768     BUF_MEM_free(ssl->init_buf);
769     ssl->init_buf = NULL;
770   }
771 }
772 
ssl_parse_extensions(const CBS * cbs,uint8_t * out_alert,const SSL_EXTENSION_TYPE * ext_types,size_t num_ext_types,int ignore_unknown)773 int ssl_parse_extensions(const CBS *cbs, uint8_t *out_alert,
774                          const SSL_EXTENSION_TYPE *ext_types,
775                          size_t num_ext_types, int ignore_unknown) {
776   /* Reset everything. */
777   for (size_t i = 0; i < num_ext_types; i++) {
778     *ext_types[i].out_present = 0;
779     CBS_init(ext_types[i].out_data, NULL, 0);
780   }
781 
782   CBS copy = *cbs;
783   while (CBS_len(&copy) != 0) {
784     uint16_t type;
785     CBS data;
786     if (!CBS_get_u16(&copy, &type) ||
787         !CBS_get_u16_length_prefixed(&copy, &data)) {
788       OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
789       *out_alert = SSL_AD_DECODE_ERROR;
790       return 0;
791     }
792 
793     const SSL_EXTENSION_TYPE *ext_type = NULL;
794     for (size_t i = 0; i < num_ext_types; i++) {
795       if (type == ext_types[i].type) {
796         ext_type = &ext_types[i];
797         break;
798       }
799     }
800 
801     if (ext_type == NULL) {
802       if (ignore_unknown) {
803         continue;
804       }
805       OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
806       *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
807       return 0;
808     }
809 
810     /* Duplicate ext_types are forbidden. */
811     if (*ext_type->out_present) {
812       OPENSSL_PUT_ERROR(SSL, SSL_R_DUPLICATE_EXTENSION);
813       *out_alert = SSL_AD_ILLEGAL_PARAMETER;
814       return 0;
815     }
816 
817     *ext_type->out_present = 1;
818     *ext_type->out_data = data;
819   }
820 
821   return 1;
822 }
823