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 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
62 return false;
63 }
64
65 for (size_t i = 0; i < 64; i++) {
66 if (!CBB_add_u8(cbb.get(), 0x20)) {
67 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
68 return false;
69 }
70 }
71
72 Span<const char> context;
73 if (cert_verify_context == ssl_cert_verify_server) {
74 static const char kContext[] = "TLS 1.3, server CertificateVerify";
75 context = kContext;
76 } else if (cert_verify_context == ssl_cert_verify_client) {
77 static const char kContext[] = "TLS 1.3, client CertificateVerify";
78 context = kContext;
79 } else if (cert_verify_context == ssl_cert_verify_channel_id) {
80 static const char kContext[] = "TLS 1.3, Channel ID";
81 context = kContext;
82 } else {
83 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
84 return false;
85 }
86
87 // Note |context| includes the NUL byte separator.
88 if (!CBB_add_bytes(cbb.get(),
89 reinterpret_cast<const uint8_t *>(context.data()),
90 context.size())) {
91 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
92 return false;
93 }
94
95 uint8_t context_hash[EVP_MAX_MD_SIZE];
96 size_t context_hash_len;
97 if (!hs->transcript.GetHash(context_hash, &context_hash_len) ||
98 !CBB_add_bytes(cbb.get(), context_hash, context_hash_len) ||
99 !CBBFinishArray(cbb.get(), out)) {
100 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
101 return false;
102 }
103
104 return true;
105 }
106
tls13_process_certificate(SSL_HANDSHAKE * hs,const SSLMessage & msg,bool allow_anonymous)107 bool tls13_process_certificate(SSL_HANDSHAKE *hs, const SSLMessage &msg,
108 bool allow_anonymous) {
109 SSL *const ssl = hs->ssl;
110 CBS body = msg.body;
111 bssl::UniquePtr<CRYPTO_BUFFER> decompressed;
112
113 if (msg.type == SSL3_MT_COMPRESSED_CERTIFICATE) {
114 CBS compressed;
115 uint16_t alg_id;
116 uint32_t uncompressed_len;
117
118 if (!CBS_get_u16(&body, &alg_id) ||
119 !CBS_get_u24(&body, &uncompressed_len) ||
120 !CBS_get_u24_length_prefixed(&body, &compressed) ||
121 CBS_len(&body) != 0) {
122 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
123 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
124 return false;
125 }
126
127 if (uncompressed_len > ssl->max_cert_list) {
128 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
129 OPENSSL_PUT_ERROR(SSL, SSL_R_UNCOMPRESSED_CERT_TOO_LARGE);
130 ERR_add_error_dataf("requested=%u",
131 static_cast<unsigned>(uncompressed_len));
132 return false;
133 }
134
135 ssl_cert_decompression_func_t decompress = nullptr;
136 for (const auto &alg : ssl->ctx->cert_compression_algs) {
137 if (alg.alg_id == alg_id) {
138 decompress = alg.decompress;
139 break;
140 }
141 }
142
143 if (decompress == nullptr) {
144 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
145 OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CERT_COMPRESSION_ALG);
146 ERR_add_error_dataf("alg=%d", static_cast<int>(alg_id));
147 return false;
148 }
149
150 CRYPTO_BUFFER *decompressed_ptr = nullptr;
151 if (!decompress(ssl, &decompressed_ptr, uncompressed_len,
152 CBS_data(&compressed), CBS_len(&compressed))) {
153 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
154 OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_DECOMPRESSION_FAILED);
155 ERR_add_error_dataf("alg=%d", static_cast<int>(alg_id));
156 return false;
157 }
158 decompressed.reset(decompressed_ptr);
159
160 if (CRYPTO_BUFFER_len(decompressed_ptr) != uncompressed_len) {
161 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
162 OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_DECOMPRESSION_FAILED);
163 ERR_add_error_dataf(
164 "alg=%d got=%u expected=%u", static_cast<int>(alg_id),
165 static_cast<unsigned>(CRYPTO_BUFFER_len(decompressed_ptr)),
166 static_cast<unsigned>(uncompressed_len));
167 return false;
168 }
169
170 CBS_init(&body, CRYPTO_BUFFER_data(decompressed_ptr),
171 CRYPTO_BUFFER_len(decompressed_ptr));
172 } else {
173 assert(msg.type == SSL3_MT_CERTIFICATE);
174 }
175
176 CBS context, certificate_list;
177 if (!CBS_get_u8_length_prefixed(&body, &context) ||
178 CBS_len(&context) != 0 ||
179 !CBS_get_u24_length_prefixed(&body, &certificate_list) ||
180 CBS_len(&body) != 0) {
181 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
182 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
183 return false;
184 }
185
186 UniquePtr<STACK_OF(CRYPTO_BUFFER)> certs(sk_CRYPTO_BUFFER_new_null());
187 if (!certs) {
188 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
189 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
190 return false;
191 }
192
193 const bool retain_sha256 =
194 ssl->server && hs->config->retain_only_sha256_of_client_certs;
195 UniquePtr<EVP_PKEY> pkey;
196 while (CBS_len(&certificate_list) > 0) {
197 CBS certificate, extensions;
198 if (!CBS_get_u24_length_prefixed(&certificate_list, &certificate) ||
199 !CBS_get_u16_length_prefixed(&certificate_list, &extensions) ||
200 CBS_len(&certificate) == 0) {
201 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
202 OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_LENGTH_MISMATCH);
203 return false;
204 }
205
206 if (sk_CRYPTO_BUFFER_num(certs.get()) == 0) {
207 pkey = ssl_cert_parse_pubkey(&certificate);
208 if (!pkey) {
209 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
210 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
211 return false;
212 }
213 // TLS 1.3 always uses certificate keys for signing thus the correct
214 // keyUsage is enforced.
215 if (!ssl_cert_check_key_usage(&certificate,
216 key_usage_digital_signature)) {
217 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
218 return false;
219 }
220
221 if (retain_sha256) {
222 // Retain the hash of the leaf certificate if requested.
223 SHA256(CBS_data(&certificate), CBS_len(&certificate),
224 hs->new_session->peer_sha256);
225 }
226 }
227
228 UniquePtr<CRYPTO_BUFFER> buf(
229 CRYPTO_BUFFER_new_from_CBS(&certificate, ssl->ctx->pool));
230 if (!buf ||
231 !PushToStack(certs.get(), std::move(buf))) {
232 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
233 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
234 return false;
235 }
236
237 // Parse out the extensions.
238 bool have_status_request = false, have_sct = false;
239 CBS status_request, sct;
240 const SSL_EXTENSION_TYPE ext_types[] = {
241 {TLSEXT_TYPE_status_request, &have_status_request, &status_request},
242 {TLSEXT_TYPE_certificate_timestamp, &have_sct, &sct},
243 };
244
245 uint8_t alert = SSL_AD_DECODE_ERROR;
246 if (!ssl_parse_extensions(&extensions, &alert, ext_types,
247 /*ignore_unknown=*/false)) {
248 ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
249 return false;
250 }
251
252 // All Certificate extensions are parsed, but only the leaf extensions are
253 // stored.
254 if (have_status_request) {
255 if (ssl->server || !hs->config->ocsp_stapling_enabled) {
256 OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
257 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
258 return false;
259 }
260
261 uint8_t status_type;
262 CBS ocsp_response;
263 if (!CBS_get_u8(&status_request, &status_type) ||
264 status_type != TLSEXT_STATUSTYPE_ocsp ||
265 !CBS_get_u24_length_prefixed(&status_request, &ocsp_response) ||
266 CBS_len(&ocsp_response) == 0 ||
267 CBS_len(&status_request) != 0) {
268 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
269 return false;
270 }
271
272 if (sk_CRYPTO_BUFFER_num(certs.get()) == 1) {
273 hs->new_session->ocsp_response.reset(
274 CRYPTO_BUFFER_new_from_CBS(&ocsp_response, ssl->ctx->pool));
275 if (hs->new_session->ocsp_response == nullptr) {
276 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
277 return false;
278 }
279 }
280 }
281
282 if (have_sct) {
283 if (ssl->server || !hs->config->signed_cert_timestamps_enabled) {
284 OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
285 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
286 return false;
287 }
288
289 if (!ssl_is_sct_list_valid(&sct)) {
290 OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_PARSING_EXTENSION);
291 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
292 return false;
293 }
294
295 if (sk_CRYPTO_BUFFER_num(certs.get()) == 1) {
296 hs->new_session->signed_cert_timestamp_list.reset(
297 CRYPTO_BUFFER_new_from_CBS(&sct, ssl->ctx->pool));
298 if (hs->new_session->signed_cert_timestamp_list == nullptr) {
299 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
300 return false;
301 }
302 }
303 }
304 }
305
306 // Store a null certificate list rather than an empty one if the peer didn't
307 // send certificates.
308 if (sk_CRYPTO_BUFFER_num(certs.get()) == 0) {
309 certs.reset();
310 }
311
312 hs->peer_pubkey = std::move(pkey);
313 hs->new_session->certs = std::move(certs);
314
315 if (!ssl->ctx->x509_method->session_cache_objects(hs->new_session.get())) {
316 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
317 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
318 return false;
319 }
320
321 if (sk_CRYPTO_BUFFER_num(hs->new_session->certs.get()) == 0) {
322 if (!allow_anonymous) {
323 OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
324 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_CERTIFICATE_REQUIRED);
325 return false;
326 }
327
328 // OpenSSL returns X509_V_OK when no certificates are requested. This is
329 // classed by them as a bug, but it's assumed by at least NGINX.
330 hs->new_session->verify_result = X509_V_OK;
331
332 // No certificate, so nothing more to do.
333 return true;
334 }
335
336 hs->new_session->peer_sha256_valid = retain_sha256;
337 return true;
338 }
339
tls13_process_certificate_verify(SSL_HANDSHAKE * hs,const SSLMessage & msg)340 bool tls13_process_certificate_verify(SSL_HANDSHAKE *hs, const SSLMessage &msg) {
341 SSL *const ssl = hs->ssl;
342 if (hs->peer_pubkey == NULL) {
343 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
344 return false;
345 }
346
347 CBS body = msg.body, signature;
348 uint16_t signature_algorithm;
349 if (!CBS_get_u16(&body, &signature_algorithm) ||
350 !CBS_get_u16_length_prefixed(&body, &signature) ||
351 CBS_len(&body) != 0) {
352 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
353 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
354 return false;
355 }
356
357 uint8_t alert = SSL_AD_DECODE_ERROR;
358 if (!tls12_check_peer_sigalg(hs, &alert, signature_algorithm)) {
359 ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
360 return false;
361 }
362 hs->new_session->peer_signature_algorithm = signature_algorithm;
363
364 Array<uint8_t> input;
365 if (!tls13_get_cert_verify_signature_input(
366 hs, &input,
367 ssl->server ? ssl_cert_verify_client : ssl_cert_verify_server)) {
368 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
369 return false;
370 }
371
372 if (!ssl_public_key_verify(ssl, signature, signature_algorithm,
373 hs->peer_pubkey.get(), input)) {
374 OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SIGNATURE);
375 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
376 return false;
377 }
378
379 return true;
380 }
381
tls13_process_finished(SSL_HANDSHAKE * hs,const SSLMessage & msg,bool use_saved_value)382 bool tls13_process_finished(SSL_HANDSHAKE *hs, const SSLMessage &msg,
383 bool use_saved_value) {
384 SSL *const ssl = hs->ssl;
385 uint8_t verify_data_buf[EVP_MAX_MD_SIZE];
386 Span<const uint8_t> verify_data;
387 if (use_saved_value) {
388 assert(ssl->server);
389 verify_data = hs->expected_client_finished();
390 } else {
391 size_t len;
392 if (!tls13_finished_mac(hs, verify_data_buf, &len, !ssl->server)) {
393 return false;
394 }
395 verify_data = MakeConstSpan(verify_data_buf, len);
396 }
397
398 bool finished_ok =
399 CBS_mem_equal(&msg.body, verify_data.data(), verify_data.size());
400 #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
401 finished_ok = true;
402 #endif
403 if (!finished_ok) {
404 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
405 OPENSSL_PUT_ERROR(SSL, SSL_R_DIGEST_CHECK_FAILED);
406 return false;
407 }
408
409 return true;
410 }
411
tls13_add_certificate(SSL_HANDSHAKE * hs)412 bool tls13_add_certificate(SSL_HANDSHAKE *hs) {
413 SSL *const ssl = hs->ssl;
414 CERT *const cert = hs->config->cert.get();
415 DC *const dc = cert->dc.get();
416
417 ScopedCBB cbb;
418 CBB *body, body_storage, certificate_list;
419
420 if (hs->cert_compression_negotiated) {
421 if (!CBB_init(cbb.get(), 1024)) {
422 return false;
423 }
424 body = cbb.get();
425 } else {
426 body = &body_storage;
427 if (!ssl->method->init_message(ssl, cbb.get(), body, SSL3_MT_CERTIFICATE)) {
428 return false;
429 }
430 }
431
432 if (// The request context is always empty in the handshake.
433 !CBB_add_u8(body, 0) ||
434 !CBB_add_u24_length_prefixed(body, &certificate_list)) {
435 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
436 return false;
437 }
438
439 if (!ssl_has_certificate(hs)) {
440 return ssl_add_message_cbb(ssl, cbb.get());
441 }
442
443 CRYPTO_BUFFER *leaf_buf = sk_CRYPTO_BUFFER_value(cert->chain.get(), 0);
444 CBB leaf, extensions;
445 if (!CBB_add_u24_length_prefixed(&certificate_list, &leaf) ||
446 !CBB_add_bytes(&leaf, CRYPTO_BUFFER_data(leaf_buf),
447 CRYPTO_BUFFER_len(leaf_buf)) ||
448 !CBB_add_u16_length_prefixed(&certificate_list, &extensions)) {
449 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
450 return false;
451 }
452
453 if (hs->scts_requested && cert->signed_cert_timestamp_list != nullptr) {
454 CBB contents;
455 if (!CBB_add_u16(&extensions, TLSEXT_TYPE_certificate_timestamp) ||
456 !CBB_add_u16_length_prefixed(&extensions, &contents) ||
457 !CBB_add_bytes(
458 &contents,
459 CRYPTO_BUFFER_data(cert->signed_cert_timestamp_list.get()),
460 CRYPTO_BUFFER_len(cert->signed_cert_timestamp_list.get())) ||
461 !CBB_flush(&extensions)) {
462 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
463 return false;
464 }
465 }
466
467 if (hs->ocsp_stapling_requested && cert->ocsp_response != NULL) {
468 CBB contents, ocsp_response;
469 if (!CBB_add_u16(&extensions, TLSEXT_TYPE_status_request) ||
470 !CBB_add_u16_length_prefixed(&extensions, &contents) ||
471 !CBB_add_u8(&contents, TLSEXT_STATUSTYPE_ocsp) ||
472 !CBB_add_u24_length_prefixed(&contents, &ocsp_response) ||
473 !CBB_add_bytes(&ocsp_response,
474 CRYPTO_BUFFER_data(cert->ocsp_response.get()),
475 CRYPTO_BUFFER_len(cert->ocsp_response.get())) ||
476 !CBB_flush(&extensions)) {
477 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
478 return false;
479 }
480 }
481
482 if (ssl_signing_with_dc(hs)) {
483 const CRYPTO_BUFFER *raw = dc->raw.get();
484 CBB child;
485 if (!CBB_add_u16(&extensions, TLSEXT_TYPE_delegated_credential) ||
486 !CBB_add_u16_length_prefixed(&extensions, &child) ||
487 !CBB_add_bytes(&child, CRYPTO_BUFFER_data(raw),
488 CRYPTO_BUFFER_len(raw)) ||
489 !CBB_flush(&extensions)) {
490 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
491 return 0;
492 }
493 ssl->s3->delegated_credential_used = true;
494 }
495
496 for (size_t i = 1; i < sk_CRYPTO_BUFFER_num(cert->chain.get()); i++) {
497 CRYPTO_BUFFER *cert_buf = sk_CRYPTO_BUFFER_value(cert->chain.get(), i);
498 CBB child;
499 if (!CBB_add_u24_length_prefixed(&certificate_list, &child) ||
500 !CBB_add_bytes(&child, CRYPTO_BUFFER_data(cert_buf),
501 CRYPTO_BUFFER_len(cert_buf)) ||
502 !CBB_add_u16(&certificate_list, 0 /* no extensions */)) {
503 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
504 return false;
505 }
506 }
507
508 if (!hs->cert_compression_negotiated) {
509 return ssl_add_message_cbb(ssl, cbb.get());
510 }
511
512 Array<uint8_t> msg;
513 if (!CBBFinishArray(cbb.get(), &msg)) {
514 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
515 return false;
516 }
517
518 const CertCompressionAlg *alg = nullptr;
519 for (const auto &candidate : ssl->ctx->cert_compression_algs) {
520 if (candidate.alg_id == hs->cert_compression_alg_id) {
521 alg = &candidate;
522 break;
523 }
524 }
525
526 if (alg == nullptr || alg->compress == nullptr) {
527 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
528 return false;
529 }
530
531 CBB compressed;
532 body = &body_storage;
533 if (!ssl->method->init_message(ssl, cbb.get(), body,
534 SSL3_MT_COMPRESSED_CERTIFICATE) ||
535 !CBB_add_u16(body, hs->cert_compression_alg_id) ||
536 !CBB_add_u24(body, msg.size()) ||
537 !CBB_add_u24_length_prefixed(body, &compressed) ||
538 !alg->compress(ssl, &compressed, msg.data(), msg.size()) ||
539 !ssl_add_message_cbb(ssl, cbb.get())) {
540 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
541 return false;
542 }
543
544 return true;
545 }
546
tls13_add_certificate_verify(SSL_HANDSHAKE * hs)547 enum ssl_private_key_result_t tls13_add_certificate_verify(SSL_HANDSHAKE *hs) {
548 SSL *const ssl = hs->ssl;
549 uint16_t signature_algorithm;
550 if (!tls1_choose_signature_algorithm(hs, &signature_algorithm)) {
551 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
552 return ssl_private_key_failure;
553 }
554
555 ScopedCBB cbb;
556 CBB body;
557 if (!ssl->method->init_message(ssl, cbb.get(), &body,
558 SSL3_MT_CERTIFICATE_VERIFY) ||
559 !CBB_add_u16(&body, signature_algorithm)) {
560 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
561 return ssl_private_key_failure;
562 }
563
564 // Sign the digest.
565 CBB child;
566 const size_t max_sig_len = EVP_PKEY_size(hs->local_pubkey.get());
567 uint8_t *sig;
568 size_t sig_len;
569 if (!CBB_add_u16_length_prefixed(&body, &child) ||
570 !CBB_reserve(&child, &sig, max_sig_len)) {
571 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
572 return ssl_private_key_failure;
573 }
574
575 Array<uint8_t> msg;
576 if (!tls13_get_cert_verify_signature_input(
577 hs, &msg,
578 ssl->server ? ssl_cert_verify_server : ssl_cert_verify_client)) {
579 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
580 return ssl_private_key_failure;
581 }
582
583 enum ssl_private_key_result_t sign_result = ssl_private_key_sign(
584 hs, sig, &sig_len, max_sig_len, signature_algorithm, msg);
585 if (sign_result != ssl_private_key_success) {
586 return sign_result;
587 }
588
589 if (!CBB_did_write(&child, sig_len) ||
590 !ssl_add_message_cbb(ssl, cbb.get())) {
591 return ssl_private_key_failure;
592 }
593
594 return ssl_private_key_success;
595 }
596
tls13_add_finished(SSL_HANDSHAKE * hs)597 bool tls13_add_finished(SSL_HANDSHAKE *hs) {
598 SSL *const ssl = hs->ssl;
599 size_t verify_data_len;
600 uint8_t verify_data[EVP_MAX_MD_SIZE];
601
602 if (!tls13_finished_mac(hs, verify_data, &verify_data_len, ssl->server)) {
603 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
604 OPENSSL_PUT_ERROR(SSL, SSL_R_DIGEST_CHECK_FAILED);
605 return false;
606 }
607
608 ScopedCBB cbb;
609 CBB body;
610 if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_FINISHED) ||
611 !CBB_add_bytes(&body, verify_data, verify_data_len) ||
612 !ssl_add_message_cbb(ssl, cbb.get())) {
613 return false;
614 }
615
616 return true;
617 }
618
tls13_add_key_update(SSL * ssl,int update_requested)619 bool tls13_add_key_update(SSL *ssl, int update_requested) {
620 ScopedCBB cbb;
621 CBB body_cbb;
622 if (!ssl->method->init_message(ssl, cbb.get(), &body_cbb,
623 SSL3_MT_KEY_UPDATE) ||
624 !CBB_add_u8(&body_cbb, update_requested) ||
625 !ssl_add_message_cbb(ssl, cbb.get()) ||
626 !tls13_rotate_traffic_key(ssl, evp_aead_seal)) {
627 return false;
628 }
629
630 // Suppress KeyUpdate acknowledgments until this change is written to the
631 // wire. This prevents us from accumulating write obligations when read and
632 // write progress at different rates. See RFC 8446, section 4.6.3.
633 ssl->s3->key_update_pending = true;
634
635 return true;
636 }
637
tls13_receive_key_update(SSL * ssl,const SSLMessage & msg)638 static bool tls13_receive_key_update(SSL *ssl, const SSLMessage &msg) {
639 CBS body = msg.body;
640 uint8_t key_update_request;
641 if (!CBS_get_u8(&body, &key_update_request) ||
642 CBS_len(&body) != 0 ||
643 (key_update_request != SSL_KEY_UPDATE_NOT_REQUESTED &&
644 key_update_request != SSL_KEY_UPDATE_REQUESTED)) {
645 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
646 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
647 return false;
648 }
649
650 if (!tls13_rotate_traffic_key(ssl, evp_aead_open)) {
651 return false;
652 }
653
654 // Acknowledge the KeyUpdate
655 if (key_update_request == SSL_KEY_UPDATE_REQUESTED &&
656 !ssl->s3->key_update_pending &&
657 !tls13_add_key_update(ssl, SSL_KEY_UPDATE_NOT_REQUESTED)) {
658 return false;
659 }
660
661 return true;
662 }
663
tls13_post_handshake(SSL * ssl,const SSLMessage & msg)664 bool tls13_post_handshake(SSL *ssl, const SSLMessage &msg) {
665 if (msg.type == SSL3_MT_KEY_UPDATE) {
666 ssl->s3->key_update_count++;
667 if (ssl->quic_method != nullptr ||
668 ssl->s3->key_update_count > kMaxKeyUpdates) {
669 OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_KEY_UPDATES);
670 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
671 return false;
672 }
673
674 return tls13_receive_key_update(ssl, msg);
675 }
676
677 ssl->s3->key_update_count = 0;
678
679 if (msg.type == SSL3_MT_NEW_SESSION_TICKET && !ssl->server) {
680 return tls13_process_new_session_ticket(ssl, msg);
681 }
682
683 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
684 OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
685 return false;
686 }
687
688 BSSL_NAMESPACE_END
689