1 /* Copyright (c) 2016, Google Inc.
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15 #include <openssl/ssl.h>
16
17 #include <assert.h>
18 #include <string.h>
19
20 #include <utility>
21
22 #include <openssl/bytestring.h>
23 #include <openssl/err.h>
24 #include <openssl/hkdf.h>
25 #include <openssl/mem.h>
26 #include <openssl/stack.h>
27 #include <openssl/x509.h>
28
29 #include "../crypto/internal.h"
30 #include "internal.h"
31
32
33 BSSL_NAMESPACE_BEGIN
34
35 // kMaxKeyUpdates is the number of consecutive KeyUpdates that will be
36 // processed. Without this limit an attacker could force unbounded processing
37 // without being able to return application data.
38 static const uint8_t kMaxKeyUpdates = 32;
39
40 const uint8_t kHelloRetryRequest[SSL3_RANDOM_SIZE] = {
41 0xcf, 0x21, 0xad, 0x74, 0xe5, 0x9a, 0x61, 0x11, 0xbe, 0x1d, 0x8c,
42 0x02, 0x1e, 0x65, 0xb8, 0x91, 0xc2, 0xa2, 0x11, 0x16, 0x7a, 0xbb,
43 0x8c, 0x5e, 0x07, 0x9e, 0x09, 0xe2, 0xc8, 0xa8, 0x33, 0x9c,
44 };
45
46 // See RFC 8446, section 4.1.3.
47 const uint8_t kTLS12DowngradeRandom[8] = {0x44, 0x4f, 0x57, 0x4e,
48 0x47, 0x52, 0x44, 0x00};
49 const uint8_t kTLS13DowngradeRandom[8] = {0x44, 0x4f, 0x57, 0x4e,
50 0x47, 0x52, 0x44, 0x01};
51
52 // This is a non-standard randomly-generated value.
53 const uint8_t kJDK11DowngradeRandom[8] = {0xed, 0xbf, 0xb4, 0xa8,
54 0xc2, 0x47, 0x10, 0xff};
55
tls13_get_cert_verify_signature_input(SSL_HANDSHAKE * hs,Array<uint8_t> * out,enum ssl_cert_verify_context_t cert_verify_context)56 bool tls13_get_cert_verify_signature_input(
57 SSL_HANDSHAKE *hs, Array<uint8_t> *out,
58 enum ssl_cert_verify_context_t cert_verify_context) {
59 ScopedCBB cbb;
60 if (!CBB_init(cbb.get(), 64 + 33 + 1 + 2 * EVP_MAX_MD_SIZE)) {
61 return false;
62 }
63
64 for (size_t i = 0; i < 64; i++) {
65 if (!CBB_add_u8(cbb.get(), 0x20)) {
66 return false;
67 }
68 }
69
70 Span<const char> context;
71 if (cert_verify_context == ssl_cert_verify_server) {
72 static const char kContext[] = "TLS 1.3, server CertificateVerify";
73 context = kContext;
74 } else if (cert_verify_context == ssl_cert_verify_client) {
75 static const char kContext[] = "TLS 1.3, client CertificateVerify";
76 context = kContext;
77 } else if (cert_verify_context == ssl_cert_verify_channel_id) {
78 static const char kContext[] = "TLS 1.3, Channel ID";
79 context = kContext;
80 } else {
81 return false;
82 }
83
84 // Note |context| includes the NUL byte separator.
85 if (!CBB_add_bytes(cbb.get(),
86 reinterpret_cast<const uint8_t *>(context.data()),
87 context.size())) {
88 return false;
89 }
90
91 uint8_t context_hash[EVP_MAX_MD_SIZE];
92 size_t context_hash_len;
93 if (!hs->transcript.GetHash(context_hash, &context_hash_len) ||
94 !CBB_add_bytes(cbb.get(), context_hash, context_hash_len) ||
95 !CBBFinishArray(cbb.get(), out)) {
96 return false;
97 }
98
99 return true;
100 }
101
tls13_process_certificate(SSL_HANDSHAKE * hs,const SSLMessage & msg,bool allow_anonymous)102 bool tls13_process_certificate(SSL_HANDSHAKE *hs, const SSLMessage &msg,
103 bool allow_anonymous) {
104 SSL *const ssl = hs->ssl;
105 CBS body = msg.body;
106 bssl::UniquePtr<CRYPTO_BUFFER> decompressed;
107
108 if (msg.type == SSL3_MT_COMPRESSED_CERTIFICATE) {
109 CBS compressed;
110 uint16_t alg_id;
111 uint32_t uncompressed_len;
112
113 if (!CBS_get_u16(&body, &alg_id) ||
114 !CBS_get_u24(&body, &uncompressed_len) ||
115 !CBS_get_u24_length_prefixed(&body, &compressed) ||
116 CBS_len(&body) != 0) {
117 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
118 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
119 return false;
120 }
121
122 if (uncompressed_len > ssl->max_cert_list) {
123 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
124 OPENSSL_PUT_ERROR(SSL, SSL_R_UNCOMPRESSED_CERT_TOO_LARGE);
125 ERR_add_error_dataf("requested=%u",
126 static_cast<unsigned>(uncompressed_len));
127 return false;
128 }
129
130 ssl_cert_decompression_func_t decompress = nullptr;
131 for (const auto &alg : ssl->ctx->cert_compression_algs) {
132 if (alg.alg_id == alg_id) {
133 decompress = alg.decompress;
134 break;
135 }
136 }
137
138 if (decompress == nullptr) {
139 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
140 OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CERT_COMPRESSION_ALG);
141 ERR_add_error_dataf("alg=%d", static_cast<int>(alg_id));
142 return false;
143 }
144
145 CRYPTO_BUFFER *decompressed_ptr = nullptr;
146 if (!decompress(ssl, &decompressed_ptr, uncompressed_len,
147 CBS_data(&compressed), CBS_len(&compressed))) {
148 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
149 OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_DECOMPRESSION_FAILED);
150 ERR_add_error_dataf("alg=%d", static_cast<int>(alg_id));
151 return false;
152 }
153 decompressed.reset(decompressed_ptr);
154
155 if (CRYPTO_BUFFER_len(decompressed_ptr) != uncompressed_len) {
156 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
157 OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_DECOMPRESSION_FAILED);
158 ERR_add_error_dataf(
159 "alg=%d got=%u expected=%u", static_cast<int>(alg_id),
160 static_cast<unsigned>(CRYPTO_BUFFER_len(decompressed_ptr)),
161 static_cast<unsigned>(uncompressed_len));
162 return false;
163 }
164
165 CBS_init(&body, CRYPTO_BUFFER_data(decompressed_ptr),
166 CRYPTO_BUFFER_len(decompressed_ptr));
167 } else {
168 assert(msg.type == SSL3_MT_CERTIFICATE);
169 }
170
171 CBS context, certificate_list;
172 if (!CBS_get_u8_length_prefixed(&body, &context) ||
173 CBS_len(&context) != 0 ||
174 !CBS_get_u24_length_prefixed(&body, &certificate_list) ||
175 CBS_len(&body) != 0) {
176 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
177 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
178 return false;
179 }
180
181 UniquePtr<STACK_OF(CRYPTO_BUFFER)> certs(sk_CRYPTO_BUFFER_new_null());
182 if (!certs) {
183 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
184 return false;
185 }
186
187 const bool retain_sha256 =
188 ssl->server && hs->config->retain_only_sha256_of_client_certs;
189 UniquePtr<EVP_PKEY> pkey;
190 while (CBS_len(&certificate_list) > 0) {
191 CBS certificate, extensions;
192 if (!CBS_get_u24_length_prefixed(&certificate_list, &certificate) ||
193 !CBS_get_u16_length_prefixed(&certificate_list, &extensions) ||
194 CBS_len(&certificate) == 0) {
195 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
196 OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_LENGTH_MISMATCH);
197 return false;
198 }
199
200 if (sk_CRYPTO_BUFFER_num(certs.get()) == 0) {
201 pkey = ssl_cert_parse_pubkey(&certificate);
202 if (!pkey) {
203 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
204 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
205 return false;
206 }
207 // TLS 1.3 always uses certificate keys for signing thus the correct
208 // keyUsage is enforced.
209 if (!ssl_cert_check_key_usage(&certificate,
210 key_usage_digital_signature)) {
211 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
212 return false;
213 }
214
215 if (retain_sha256) {
216 // Retain the hash of the leaf certificate if requested.
217 SHA256(CBS_data(&certificate), CBS_len(&certificate),
218 hs->new_session->peer_sha256);
219 }
220 }
221
222 UniquePtr<CRYPTO_BUFFER> buf(
223 CRYPTO_BUFFER_new_from_CBS(&certificate, ssl->ctx->pool));
224 if (!buf ||
225 !PushToStack(certs.get(), std::move(buf))) {
226 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
227 return false;
228 }
229
230 // Parse out the extensions.
231 SSLExtension status_request(
232 TLSEXT_TYPE_status_request,
233 !ssl->server && hs->config->ocsp_stapling_enabled);
234 SSLExtension sct(
235 TLSEXT_TYPE_certificate_timestamp,
236 !ssl->server && hs->config->signed_cert_timestamps_enabled);
237 uint8_t alert = SSL_AD_DECODE_ERROR;
238 if (!ssl_parse_extensions(&extensions, &alert, {&status_request, &sct},
239 /*ignore_unknown=*/false)) {
240 ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
241 return false;
242 }
243
244 // All Certificate extensions are parsed, but only the leaf extensions are
245 // stored.
246 if (status_request.present) {
247 uint8_t status_type;
248 CBS ocsp_response;
249 if (!CBS_get_u8(&status_request.data, &status_type) ||
250 status_type != TLSEXT_STATUSTYPE_ocsp ||
251 !CBS_get_u24_length_prefixed(&status_request.data, &ocsp_response) ||
252 CBS_len(&ocsp_response) == 0 ||
253 CBS_len(&status_request.data) != 0) {
254 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
255 return false;
256 }
257
258 if (sk_CRYPTO_BUFFER_num(certs.get()) == 1) {
259 hs->new_session->ocsp_response.reset(
260 CRYPTO_BUFFER_new_from_CBS(&ocsp_response, ssl->ctx->pool));
261 if (hs->new_session->ocsp_response == nullptr) {
262 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
263 return false;
264 }
265 }
266 }
267
268 if (sct.present) {
269 if (!ssl_is_sct_list_valid(&sct.data)) {
270 OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_PARSING_EXTENSION);
271 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
272 return false;
273 }
274
275 if (sk_CRYPTO_BUFFER_num(certs.get()) == 1) {
276 hs->new_session->signed_cert_timestamp_list.reset(
277 CRYPTO_BUFFER_new_from_CBS(&sct.data, ssl->ctx->pool));
278 if (hs->new_session->signed_cert_timestamp_list == nullptr) {
279 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
280 return false;
281 }
282 }
283 }
284 }
285
286 // Store a null certificate list rather than an empty one if the peer didn't
287 // send certificates.
288 if (sk_CRYPTO_BUFFER_num(certs.get()) == 0) {
289 certs.reset();
290 }
291
292 hs->peer_pubkey = std::move(pkey);
293 hs->new_session->certs = std::move(certs);
294
295 if (!ssl->ctx->x509_method->session_cache_objects(hs->new_session.get())) {
296 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
297 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
298 return false;
299 }
300
301 if (sk_CRYPTO_BUFFER_num(hs->new_session->certs.get()) == 0) {
302 if (!allow_anonymous) {
303 OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
304 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_CERTIFICATE_REQUIRED);
305 return false;
306 }
307
308 // OpenSSL returns X509_V_OK when no certificates are requested. This is
309 // classed by them as a bug, but it's assumed by at least NGINX.
310 hs->new_session->verify_result = X509_V_OK;
311
312 // No certificate, so nothing more to do.
313 return true;
314 }
315
316 hs->new_session->peer_sha256_valid = retain_sha256;
317 return true;
318 }
319
tls13_process_certificate_verify(SSL_HANDSHAKE * hs,const SSLMessage & msg)320 bool tls13_process_certificate_verify(SSL_HANDSHAKE *hs, const SSLMessage &msg) {
321 SSL *const ssl = hs->ssl;
322 if (hs->peer_pubkey == NULL) {
323 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
324 return false;
325 }
326
327 CBS body = msg.body, signature;
328 uint16_t signature_algorithm;
329 if (!CBS_get_u16(&body, &signature_algorithm) ||
330 !CBS_get_u16_length_prefixed(&body, &signature) ||
331 CBS_len(&body) != 0) {
332 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
333 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
334 return false;
335 }
336
337 uint8_t alert = SSL_AD_DECODE_ERROR;
338 if (!tls12_check_peer_sigalg(hs, &alert, signature_algorithm)) {
339 ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
340 return false;
341 }
342 hs->new_session->peer_signature_algorithm = signature_algorithm;
343
344 Array<uint8_t> input;
345 if (!tls13_get_cert_verify_signature_input(
346 hs, &input,
347 ssl->server ? ssl_cert_verify_client : ssl_cert_verify_server)) {
348 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
349 return false;
350 }
351
352 if (!ssl_public_key_verify(ssl, signature, signature_algorithm,
353 hs->peer_pubkey.get(), input)) {
354 OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SIGNATURE);
355 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
356 return false;
357 }
358
359 return true;
360 }
361
tls13_process_finished(SSL_HANDSHAKE * hs,const SSLMessage & msg,bool use_saved_value)362 bool tls13_process_finished(SSL_HANDSHAKE *hs, const SSLMessage &msg,
363 bool use_saved_value) {
364 SSL *const ssl = hs->ssl;
365 uint8_t verify_data_buf[EVP_MAX_MD_SIZE];
366 Span<const uint8_t> verify_data;
367 if (use_saved_value) {
368 assert(ssl->server);
369 verify_data = hs->expected_client_finished();
370 } else {
371 size_t len;
372 if (!tls13_finished_mac(hs, verify_data_buf, &len, !ssl->server)) {
373 return false;
374 }
375 verify_data = MakeConstSpan(verify_data_buf, len);
376 }
377
378 bool finished_ok =
379 CBS_mem_equal(&msg.body, verify_data.data(), verify_data.size());
380 #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
381 finished_ok = true;
382 #endif
383 if (!finished_ok) {
384 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
385 OPENSSL_PUT_ERROR(SSL, SSL_R_DIGEST_CHECK_FAILED);
386 return false;
387 }
388
389 return true;
390 }
391
tls13_add_certificate(SSL_HANDSHAKE * hs)392 bool tls13_add_certificate(SSL_HANDSHAKE *hs) {
393 SSL *const ssl = hs->ssl;
394 const SSL_CREDENTIAL *cred = hs->credential.get();
395
396 ScopedCBB cbb;
397 CBB *body, body_storage, certificate_list;
398
399 if (hs->cert_compression_negotiated) {
400 if (!CBB_init(cbb.get(), 1024)) {
401 return false;
402 }
403 body = cbb.get();
404 } else {
405 body = &body_storage;
406 if (!ssl->method->init_message(ssl, cbb.get(), body, SSL3_MT_CERTIFICATE)) {
407 return false;
408 }
409 }
410
411 if (// The request context is always empty in the handshake.
412 !CBB_add_u8(body, 0) ||
413 !CBB_add_u24_length_prefixed(body, &certificate_list)) {
414 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
415 return false;
416 }
417
418 if (hs->credential == nullptr) {
419 return ssl_add_message_cbb(ssl, cbb.get());
420 }
421
422 assert(hs->credential->UsesX509());
423 CRYPTO_BUFFER *leaf_buf = sk_CRYPTO_BUFFER_value(cred->chain.get(), 0);
424 CBB leaf, extensions;
425 if (!CBB_add_u24_length_prefixed(&certificate_list, &leaf) ||
426 !CBB_add_bytes(&leaf, CRYPTO_BUFFER_data(leaf_buf),
427 CRYPTO_BUFFER_len(leaf_buf)) ||
428 !CBB_add_u16_length_prefixed(&certificate_list, &extensions)) {
429 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
430 return false;
431 }
432
433 if (hs->scts_requested && cred->signed_cert_timestamp_list != nullptr) {
434 CBB contents;
435 if (!CBB_add_u16(&extensions, TLSEXT_TYPE_certificate_timestamp) ||
436 !CBB_add_u16_length_prefixed(&extensions, &contents) ||
437 !CBB_add_bytes(
438 &contents,
439 CRYPTO_BUFFER_data(cred->signed_cert_timestamp_list.get()),
440 CRYPTO_BUFFER_len(cred->signed_cert_timestamp_list.get())) ||
441 !CBB_flush(&extensions)) {
442 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
443 return false;
444 }
445 }
446
447 if (hs->ocsp_stapling_requested && cred->ocsp_response != NULL) {
448 CBB contents, ocsp_response;
449 if (!CBB_add_u16(&extensions, TLSEXT_TYPE_status_request) ||
450 !CBB_add_u16_length_prefixed(&extensions, &contents) ||
451 !CBB_add_u8(&contents, TLSEXT_STATUSTYPE_ocsp) ||
452 !CBB_add_u24_length_prefixed(&contents, &ocsp_response) ||
453 !CBB_add_bytes(&ocsp_response,
454 CRYPTO_BUFFER_data(cred->ocsp_response.get()),
455 CRYPTO_BUFFER_len(cred->ocsp_response.get())) ||
456 !CBB_flush(&extensions)) {
457 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
458 return false;
459 }
460 }
461
462 if (cred->type == SSLCredentialType::kDelegated) {
463 CBB child;
464 if (!CBB_add_u16(&extensions, TLSEXT_TYPE_delegated_credential) ||
465 !CBB_add_u16_length_prefixed(&extensions, &child) ||
466 !CBB_add_bytes(&child, CRYPTO_BUFFER_data(cred->dc.get()),
467 CRYPTO_BUFFER_len(cred->dc.get())) ||
468 !CBB_flush(&extensions)) {
469 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
470 return false;
471 }
472 }
473
474 for (size_t i = 1; i < sk_CRYPTO_BUFFER_num(cred->chain.get()); i++) {
475 CRYPTO_BUFFER *cert_buf = sk_CRYPTO_BUFFER_value(cred->chain.get(), i);
476 CBB child;
477 if (!CBB_add_u24_length_prefixed(&certificate_list, &child) ||
478 !CBB_add_bytes(&child, CRYPTO_BUFFER_data(cert_buf),
479 CRYPTO_BUFFER_len(cert_buf)) ||
480 !CBB_add_u16(&certificate_list, 0 /* no extensions */)) {
481 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
482 return false;
483 }
484 }
485
486 if (!hs->cert_compression_negotiated) {
487 return ssl_add_message_cbb(ssl, cbb.get());
488 }
489
490 Array<uint8_t> msg;
491 if (!CBBFinishArray(cbb.get(), &msg)) {
492 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
493 return false;
494 }
495
496 const CertCompressionAlg *alg = nullptr;
497 for (const auto &candidate : ssl->ctx->cert_compression_algs) {
498 if (candidate.alg_id == hs->cert_compression_alg_id) {
499 alg = &candidate;
500 break;
501 }
502 }
503
504 if (alg == nullptr || alg->compress == nullptr) {
505 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
506 return false;
507 }
508
509 CBB compressed;
510 body = &body_storage;
511 if (!ssl->method->init_message(ssl, cbb.get(), body,
512 SSL3_MT_COMPRESSED_CERTIFICATE) ||
513 !CBB_add_u16(body, hs->cert_compression_alg_id) ||
514 msg.size() > (1u << 24) - 1 || //
515 !CBB_add_u24(body, static_cast<uint32_t>(msg.size())) ||
516 !CBB_add_u24_length_prefixed(body, &compressed)) {
517 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
518 return false;
519 }
520
521 SSL_HANDSHAKE_HINTS *const hints = hs->hints.get();
522 if (hints && !hs->hints_requested &&
523 hints->cert_compression_alg_id == hs->cert_compression_alg_id &&
524 hints->cert_compression_input == MakeConstSpan(msg) &&
525 !hints->cert_compression_output.empty()) {
526 if (!CBB_add_bytes(&compressed, hints->cert_compression_output.data(),
527 hints->cert_compression_output.size())) {
528 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
529 return false;
530 }
531 } else {
532 if (!alg->compress(ssl, &compressed, msg.data(), msg.size())) {
533 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
534 return false;
535 }
536 if (hints && hs->hints_requested) {
537 hints->cert_compression_alg_id = hs->cert_compression_alg_id;
538 if (!hints->cert_compression_input.CopyFrom(msg) ||
539 !hints->cert_compression_output.CopyFrom(
540 MakeConstSpan(CBB_data(&compressed), CBB_len(&compressed)))) {
541 return false;
542 }
543 }
544 }
545
546 if (!ssl_add_message_cbb(ssl, cbb.get())) {
547 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
548 return false;
549 }
550
551 return true;
552 }
553
tls13_add_certificate_verify(SSL_HANDSHAKE * hs)554 enum ssl_private_key_result_t tls13_add_certificate_verify(SSL_HANDSHAKE *hs) {
555 SSL *const ssl = hs->ssl;
556 assert(hs->signature_algorithm != 0);
557 ScopedCBB cbb;
558 CBB body;
559 if (!ssl->method->init_message(ssl, cbb.get(), &body,
560 SSL3_MT_CERTIFICATE_VERIFY) ||
561 !CBB_add_u16(&body, hs->signature_algorithm)) {
562 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
563 return ssl_private_key_failure;
564 }
565
566 CBB child;
567 const size_t max_sig_len = EVP_PKEY_size(hs->credential->pubkey.get());
568 uint8_t *sig;
569 size_t sig_len;
570 if (!CBB_add_u16_length_prefixed(&body, &child) ||
571 !CBB_reserve(&child, &sig, max_sig_len)) {
572 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
573 return ssl_private_key_failure;
574 }
575
576 Array<uint8_t> msg;
577 if (!tls13_get_cert_verify_signature_input(
578 hs, &msg,
579 ssl->server ? ssl_cert_verify_server : ssl_cert_verify_client)) {
580 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
581 return ssl_private_key_failure;
582 }
583
584 enum ssl_private_key_result_t sign_result = ssl_private_key_sign(
585 hs, sig, &sig_len, max_sig_len, hs->signature_algorithm, msg);
586 if (sign_result != ssl_private_key_success) {
587 return sign_result;
588 }
589
590 if (!CBB_did_write(&child, sig_len) ||
591 !ssl_add_message_cbb(ssl, cbb.get())) {
592 return ssl_private_key_failure;
593 }
594
595 return ssl_private_key_success;
596 }
597
tls13_add_finished(SSL_HANDSHAKE * hs)598 bool tls13_add_finished(SSL_HANDSHAKE *hs) {
599 SSL *const ssl = hs->ssl;
600 size_t verify_data_len;
601 uint8_t verify_data[EVP_MAX_MD_SIZE];
602
603 if (!tls13_finished_mac(hs, verify_data, &verify_data_len, ssl->server)) {
604 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
605 OPENSSL_PUT_ERROR(SSL, SSL_R_DIGEST_CHECK_FAILED);
606 return false;
607 }
608
609 ScopedCBB cbb;
610 CBB body;
611 if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_FINISHED) ||
612 !CBB_add_bytes(&body, verify_data, verify_data_len) ||
613 !ssl_add_message_cbb(ssl, cbb.get())) {
614 return false;
615 }
616
617 return true;
618 }
619
tls13_add_key_update(SSL * ssl,int update_requested)620 bool tls13_add_key_update(SSL *ssl, int update_requested) {
621 ScopedCBB cbb;
622 CBB body_cbb;
623 if (!ssl->method->init_message(ssl, cbb.get(), &body_cbb,
624 SSL3_MT_KEY_UPDATE) ||
625 !CBB_add_u8(&body_cbb, update_requested) ||
626 !ssl_add_message_cbb(ssl, cbb.get()) ||
627 !tls13_rotate_traffic_key(ssl, evp_aead_seal)) {
628 return false;
629 }
630
631 // Suppress KeyUpdate acknowledgments until this change is written to the
632 // wire. This prevents us from accumulating write obligations when read and
633 // write progress at different rates. See RFC 8446, section 4.6.3.
634 ssl->s3->key_update_pending = true;
635
636 return true;
637 }
638
tls13_receive_key_update(SSL * ssl,const SSLMessage & msg)639 static bool tls13_receive_key_update(SSL *ssl, const SSLMessage &msg) {
640 CBS body = msg.body;
641 uint8_t key_update_request;
642 if (!CBS_get_u8(&body, &key_update_request) ||
643 CBS_len(&body) != 0 ||
644 (key_update_request != SSL_KEY_UPDATE_NOT_REQUESTED &&
645 key_update_request != SSL_KEY_UPDATE_REQUESTED)) {
646 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
647 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
648 return false;
649 }
650
651 if (!tls13_rotate_traffic_key(ssl, evp_aead_open)) {
652 return false;
653 }
654
655 // Acknowledge the KeyUpdate
656 if (key_update_request == SSL_KEY_UPDATE_REQUESTED &&
657 !ssl->s3->key_update_pending &&
658 !tls13_add_key_update(ssl, SSL_KEY_UPDATE_NOT_REQUESTED)) {
659 return false;
660 }
661
662 return true;
663 }
664
tls13_post_handshake(SSL * ssl,const SSLMessage & msg)665 bool tls13_post_handshake(SSL *ssl, const SSLMessage &msg) {
666 if (msg.type == SSL3_MT_KEY_UPDATE) {
667 ssl->s3->key_update_count++;
668 if (ssl->quic_method != nullptr ||
669 ssl->s3->key_update_count > kMaxKeyUpdates) {
670 OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_KEY_UPDATES);
671 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
672 return false;
673 }
674
675 return tls13_receive_key_update(ssl, msg);
676 }
677
678 ssl->s3->key_update_count = 0;
679
680 if (msg.type == SSL3_MT_NEW_SESSION_TICKET && !ssl->server) {
681 return tls13_process_new_session_ticket(ssl, msg);
682 }
683
684 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
685 OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
686 return false;
687 }
688
689 BSSL_NAMESPACE_END
690