1 /* $OpenBSD: tls13_internal.h,v 1.94 2021/09/16 19:25:30 jsing Exp $ */ 2 /* 3 * Copyright (c) 2018 Bob Beck <beck@openbsd.org> 4 * Copyright (c) 2018 Theo Buehler <tb@openbsd.org> 5 * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org> 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 14 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 16 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 17 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #ifndef HEADER_TLS13_INTERNAL_H 21 #define HEADER_TLS13_INTERNAL_H 22 23 #include <openssl/evp.h> 24 #include <openssl/ssl.h> 25 26 #include "bytestring.h" 27 28 __BEGIN_HIDDEN_DECLS 29 30 #define TLS13_HS_CLIENT 1 31 #define TLS13_HS_SERVER 2 32 33 #define TLS13_IO_SUCCESS 1 34 #define TLS13_IO_EOF 0 35 #define TLS13_IO_FAILURE -1 36 #define TLS13_IO_ALERT -2 37 #define TLS13_IO_WANT_POLLIN -3 38 #define TLS13_IO_WANT_POLLOUT -4 39 #define TLS13_IO_WANT_RETRY -5 /* Retry the previous call immediately. */ 40 #define TLS13_IO_USE_LEGACY -6 41 #define TLS13_IO_RECORD_VERSION -7 42 #define TLS13_IO_RECORD_OVERFLOW -8 43 44 #define TLS13_ERR_VERIFY_FAILED 16 45 #define TLS13_ERR_HRR_FAILED 17 46 #define TLS13_ERR_TRAILING_DATA 18 47 #define TLS13_ERR_NO_SHARED_CIPHER 19 48 #define TLS13_ERR_NO_CERTIFICATE 20 49 #define TLS13_ERR_NO_PEER_CERTIFICATE 21 50 51 #define TLS13_ALERT_LEVEL_WARNING 1 52 #define TLS13_ALERT_LEVEL_FATAL 2 53 54 #define TLS13_ALERT_CLOSE_NOTIFY 0 55 #define TLS13_ALERT_UNEXPECTED_MESSAGE 10 56 #define TLS13_ALERT_BAD_RECORD_MAC 20 57 #define TLS13_ALERT_RECORD_OVERFLOW 22 58 #define TLS13_ALERT_HANDSHAKE_FAILURE 40 59 #define TLS13_ALERT_BAD_CERTIFICATE 42 60 #define TLS13_ALERT_UNSUPPORTED_CERTIFICATE 43 61 #define TLS13_ALERT_CERTIFICATE_REVOKED 44 62 #define TLS13_ALERT_CERTIFICATE_EXPIRED 45 63 #define TLS13_ALERT_CERTIFICATE_UNKNOWN 46 64 #define TLS13_ALERT_ILLEGAL_PARAMETER 47 65 #define TLS13_ALERT_UNKNOWN_CA 48 66 #define TLS13_ALERT_ACCESS_DENIED 49 67 #define TLS13_ALERT_DECODE_ERROR 50 68 #define TLS13_ALERT_DECRYPT_ERROR 51 69 #define TLS13_ALERT_PROTOCOL_VERSION 70 70 #define TLS13_ALERT_INSUFFICIENT_SECURITY 71 71 #define TLS13_ALERT_INTERNAL_ERROR 80 72 #define TLS13_ALERT_INAPPROPRIATE_FALLBACK 86 73 #define TLS13_ALERT_USER_CANCELED 90 74 #define TLS13_ALERT_MISSING_EXTENSION 109 75 #define TLS13_ALERT_UNSUPPORTED_EXTENSION 110 76 #define TLS13_ALERT_UNRECOGNIZED_NAME 112 77 #define TLS13_ALERT_BAD_CERTIFICATE_STATUS_RESPONSE 113 78 #define TLS13_ALERT_UNKNOWN_PSK_IDENTITY 115 79 #define TLS13_ALERT_CERTIFICATE_REQUIRED 116 80 #define TLS13_ALERT_NO_APPLICATION_PROTOCOL 120 81 82 #define TLS13_INFO_HANDSHAKE_STARTED SSL_CB_HANDSHAKE_START 83 #define TLS13_INFO_HANDSHAKE_COMPLETED SSL_CB_HANDSHAKE_DONE 84 #define TLS13_INFO_ACCEPT_LOOP SSL_CB_ACCEPT_LOOP 85 #define TLS13_INFO_CONNECT_LOOP SSL_CB_CONNECT_LOOP 86 #define TLS13_INFO_ACCEPT_EXIT SSL_CB_ACCEPT_EXIT 87 #define TLS13_INFO_CONNECT_EXIT SSL_CB_CONNECT_EXIT 88 89 typedef void (*tls13_alert_cb)(uint8_t _alert_desc, void *_cb_arg); 90 typedef ssize_t (*tls13_phh_recv_cb)(void *_cb_arg, CBS *_cbs); 91 typedef void (*tls13_phh_sent_cb)(void *_cb_arg); 92 typedef ssize_t (*tls13_read_cb)(void *_buf, size_t _buflen, void *_cb_arg); 93 typedef ssize_t (*tls13_write_cb)(const void *_buf, size_t _buflen, 94 void *_cb_arg); 95 typedef ssize_t (*tls13_flush_cb)(void *_cb_arg); 96 typedef void (*tls13_handshake_message_cb)(void *_cb_arg); 97 typedef void (*tls13_info_cb)(void *_cb_arg, int _state, int _ret); 98 typedef int (*tls13_ocsp_status_cb)(void *_cb_arg); 99 100 /* 101 * Buffers. 102 */ 103 struct tls13_buffer; 104 105 struct tls13_buffer *tls13_buffer_new(size_t init_size); 106 int tls13_buffer_set_data(struct tls13_buffer *buf, CBS *data); 107 void tls13_buffer_free(struct tls13_buffer *buf); 108 ssize_t tls13_buffer_extend(struct tls13_buffer *buf, size_t len, 109 tls13_read_cb read_cb, void *cb_arg); 110 void tls13_buffer_cbs(struct tls13_buffer *buf, CBS *cbs); 111 int tls13_buffer_finish(struct tls13_buffer *buf, uint8_t **out, 112 size_t *out_len); 113 114 /* 115 * Secrets. 116 */ 117 struct tls13_secret { 118 uint8_t *data; 119 size_t len; 120 }; 121 122 /* RFC 8446 Section 7.1 Page 92 */ 123 struct tls13_secrets { 124 const EVP_MD *digest; 125 int resumption; 126 int init_done; 127 int early_done; 128 int handshake_done; 129 int schedule_done; 130 int insecure; /* Set by tests */ 131 struct tls13_secret zeros; 132 struct tls13_secret empty_hash; 133 struct tls13_secret extracted_early; 134 struct tls13_secret binder_key; 135 struct tls13_secret client_early_traffic; 136 struct tls13_secret early_exporter_master; 137 struct tls13_secret derived_early; 138 struct tls13_secret extracted_handshake; 139 struct tls13_secret client_handshake_traffic; 140 struct tls13_secret server_handshake_traffic; 141 struct tls13_secret derived_handshake; 142 struct tls13_secret extracted_master; 143 struct tls13_secret client_application_traffic; 144 struct tls13_secret server_application_traffic; 145 struct tls13_secret exporter_master; 146 struct tls13_secret resumption_master; 147 }; 148 149 int tls13_secret_init(struct tls13_secret *secret, size_t len); 150 void tls13_secret_cleanup(struct tls13_secret *secret); 151 struct tls13_secrets *tls13_secrets_create(const EVP_MD *digest, 152 int resumption); 153 void tls13_secrets_destroy(struct tls13_secrets *secrets); 154 155 int tls13_hkdf_expand_label(struct tls13_secret *out, const EVP_MD *digest, 156 const struct tls13_secret *secret, const char *label, 157 const struct tls13_secret *context); 158 int tls13_hkdf_expand_label_with_length(struct tls13_secret *out, 159 const EVP_MD *digest, const struct tls13_secret *secret, 160 const uint8_t *label, size_t label_len, const struct tls13_secret *context); 161 162 int tls13_derive_secret(struct tls13_secret *out, const EVP_MD *digest, 163 const struct tls13_secret *secret, const char *label, 164 const struct tls13_secret *context); 165 int tls13_derive_secret_with_label_length(struct tls13_secret *out, 166 const EVP_MD *digest, const struct tls13_secret *secret, 167 const uint8_t *label, size_t label_len, const struct tls13_secret *context); 168 169 int tls13_derive_early_secrets(struct tls13_secrets *secrets, uint8_t *psk, 170 size_t psk_len, const struct tls13_secret *context); 171 int tls13_derive_handshake_secrets(struct tls13_secrets *secrets, 172 const uint8_t *ecdhe, size_t ecdhe_len, const struct tls13_secret *context); 173 int tls13_derive_application_secrets(struct tls13_secrets *secrets, 174 const struct tls13_secret *context); 175 int tls13_update_client_traffic_secret(struct tls13_secrets *secrets); 176 int tls13_update_server_traffic_secret(struct tls13_secrets *secrets); 177 178 /* 179 * Key shares. 180 */ 181 struct tls13_key_share; 182 183 struct tls13_key_share *tls13_key_share_new(uint16_t group_id); 184 struct tls13_key_share *tls13_key_share_new_nid(int nid); 185 void tls13_key_share_free(struct tls13_key_share *ks); 186 187 uint16_t tls13_key_share_group(struct tls13_key_share *ks); 188 int tls13_key_share_peer_pkey(struct tls13_key_share *ks, EVP_PKEY *pkey); 189 int tls13_key_share_generate(struct tls13_key_share *ks); 190 int tls13_key_share_public(struct tls13_key_share *ks, CBB *cbb); 191 int tls13_key_share_peer_public(struct tls13_key_share *ks, uint16_t group, 192 CBS *cbs); 193 int tls13_key_share_derive(struct tls13_key_share *ks, uint8_t **shared_key, 194 size_t *shared_key_len); 195 196 /* 197 * Record Layer. 198 */ 199 struct tls13_record_layer; 200 201 struct tls13_record_layer_callbacks { 202 tls13_read_cb wire_read; 203 tls13_write_cb wire_write; 204 tls13_flush_cb wire_flush; 205 tls13_alert_cb alert_recv; 206 tls13_alert_cb alert_sent; 207 tls13_phh_recv_cb phh_recv; 208 tls13_phh_sent_cb phh_sent; 209 }; 210 211 struct tls13_record_layer *tls13_record_layer_new( 212 const struct tls13_record_layer_callbacks *callbacks, void *cb_arg); 213 void tls13_record_layer_free(struct tls13_record_layer *rl); 214 void tls13_record_layer_allow_ccs(struct tls13_record_layer *rl, int allow); 215 void tls13_record_layer_allow_legacy_alerts(struct tls13_record_layer *rl, int allow); 216 void tls13_record_layer_rcontent(struct tls13_record_layer *rl, CBS *cbs); 217 void tls13_record_layer_set_aead(struct tls13_record_layer *rl, 218 const EVP_AEAD *aead); 219 void tls13_record_layer_set_hash(struct tls13_record_layer *rl, 220 const EVP_MD *hash); 221 void tls13_record_layer_set_legacy_version(struct tls13_record_layer *rl, 222 uint16_t version); 223 void tls13_record_layer_set_retry_after_phh(struct tls13_record_layer *rl, int retry); 224 void tls13_record_layer_handshake_completed(struct tls13_record_layer *rl); 225 int tls13_record_layer_set_read_traffic_key(struct tls13_record_layer *rl, 226 struct tls13_secret *read_key); 227 int tls13_record_layer_set_write_traffic_key(struct tls13_record_layer *rl, 228 struct tls13_secret *write_key); 229 ssize_t tls13_record_layer_send_pending(struct tls13_record_layer *rl); 230 ssize_t tls13_record_layer_phh(struct tls13_record_layer *rl, CBS *cbs); 231 ssize_t tls13_record_layer_flush(struct tls13_record_layer *rl); 232 233 ssize_t tls13_read_handshake_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n); 234 ssize_t tls13_write_handshake_data(struct tls13_record_layer *rl, const uint8_t *buf, 235 size_t n); 236 ssize_t tls13_pending_application_data(struct tls13_record_layer *rl); 237 ssize_t tls13_peek_application_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n); 238 ssize_t tls13_read_application_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n); 239 ssize_t tls13_write_application_data(struct tls13_record_layer *rl, const uint8_t *buf, 240 size_t n); 241 242 ssize_t tls13_send_alert(struct tls13_record_layer *rl, uint8_t alert_desc); 243 ssize_t tls13_send_dummy_ccs(struct tls13_record_layer *rl); 244 245 /* 246 * Handshake Messages. 247 */ 248 struct tls13_handshake_msg; 249 250 struct tls13_handshake_msg *tls13_handshake_msg_new(void); 251 void tls13_handshake_msg_free(struct tls13_handshake_msg *msg); 252 void tls13_handshake_msg_data(struct tls13_handshake_msg *msg, CBS *cbs); 253 int tls13_handshake_msg_set_buffer(struct tls13_handshake_msg *msg, CBS *cbs); 254 uint8_t tls13_handshake_msg_type(struct tls13_handshake_msg *msg); 255 int tls13_handshake_msg_content(struct tls13_handshake_msg *msg, CBS *cbs); 256 int tls13_handshake_msg_start(struct tls13_handshake_msg *msg, CBB *body, 257 uint8_t msg_type); 258 int tls13_handshake_msg_finish(struct tls13_handshake_msg *msg); 259 int tls13_handshake_msg_recv(struct tls13_handshake_msg *msg, 260 struct tls13_record_layer *rl); 261 int tls13_handshake_msg_send(struct tls13_handshake_msg *msg, 262 struct tls13_record_layer *rl); 263 264 struct tls13_handshake_stage { 265 uint8_t hs_type; 266 uint8_t message_number; 267 }; 268 269 struct ssl_handshake_tls13_st; 270 271 struct tls13_error { 272 int code; 273 int subcode; 274 int errnum; 275 const char *file; 276 int line; 277 char *msg; 278 }; 279 280 struct tls13_ctx { 281 struct tls13_error error; 282 283 SSL *ssl; 284 struct ssl_handshake_st *hs; 285 uint8_t mode; 286 struct tls13_handshake_stage handshake_stage; 287 int handshake_started; 288 int handshake_completed; 289 int need_flush; 290 int middlebox_compat; 291 int send_dummy_ccs; 292 int send_dummy_ccs_after; 293 294 int close_notify_sent; 295 int close_notify_recv; 296 297 const EVP_AEAD *aead; 298 const EVP_MD *hash; 299 300 struct tls13_record_layer *rl; 301 struct tls13_handshake_msg *hs_msg; 302 uint8_t key_update_request; 303 uint8_t alert; 304 int phh_count; 305 time_t phh_last_seen; 306 307 tls13_handshake_message_cb handshake_message_sent_cb; 308 tls13_handshake_message_cb handshake_message_recv_cb; 309 tls13_info_cb info_cb; 310 tls13_ocsp_status_cb ocsp_status_recv_cb; 311 }; 312 #ifndef TLS13_PHH_LIMIT_TIME 313 #define TLS13_PHH_LIMIT_TIME 3600 314 #endif 315 #ifndef TLS13_PHH_LIMIT 316 #define TLS13_PHH_LIMIT 100 317 #endif 318 319 struct tls13_ctx *tls13_ctx_new(int mode); 320 void tls13_ctx_free(struct tls13_ctx *ctx); 321 322 const EVP_AEAD *tls13_cipher_aead(const SSL_CIPHER *cipher); 323 const EVP_MD *tls13_cipher_hash(const SSL_CIPHER *cipher); 324 325 /* 326 * Legacy interfaces. 327 */ 328 int tls13_use_legacy_client(struct tls13_ctx *ctx); 329 int tls13_use_legacy_server(struct tls13_ctx *ctx); 330 int tls13_legacy_accept(SSL *ssl); 331 int tls13_legacy_connect(SSL *ssl); 332 int tls13_legacy_return_code(SSL *ssl, ssize_t ret); 333 ssize_t tls13_legacy_wire_read_cb(void *buf, size_t n, void *arg); 334 ssize_t tls13_legacy_wire_write_cb(const void *buf, size_t n, void *arg); 335 ssize_t tls13_legacy_wire_flush_cb(void *arg); 336 int tls13_legacy_pending(const SSL *ssl); 337 int tls13_legacy_read_bytes(SSL *ssl, int type, unsigned char *buf, int len, 338 int peek); 339 int tls13_legacy_write_bytes(SSL *ssl, int type, const void *buf, int len); 340 int tls13_legacy_shutdown(SSL *ssl); 341 int tls13_legacy_servername_process(struct tls13_ctx *ctx, uint8_t *alert); 342 343 /* 344 * Message Types - RFC 8446, Section B.3. 345 * 346 * Values listed as "_RESERVED" were used in previous versions of TLS and are 347 * listed here for completeness. TLS 1.3 implementations MUST NOT send them but 348 * might receive them from older TLS implementations. 349 */ 350 #define TLS13_MT_HELLO_REQUEST_RESERVED 0 351 #define TLS13_MT_CLIENT_HELLO 1 352 #define TLS13_MT_SERVER_HELLO 2 353 #define TLS13_MT_HELLO_VERIFY_REQUEST_RESERVED 3 354 #define TLS13_MT_NEW_SESSION_TICKET 4 355 #define TLS13_MT_END_OF_EARLY_DATA 5 356 #define TLS13_MT_HELLO_RETRY_REQUEST_RESERVED 6 357 #define TLS13_MT_ENCRYPTED_EXTENSIONS 8 358 #define TLS13_MT_CERTIFICATE 11 359 #define TLS13_MT_SERVER_KEY_EXCHANGE_RESERVED 12 360 #define TLS13_MT_CERTIFICATE_REQUEST 13 361 #define TLS13_MT_SERVER_HELLO_DONE_RESERVED 14 362 #define TLS13_MT_CERTIFICATE_VERIFY 15 363 #define TLS13_MT_CLIENT_KEY_EXCHANGE_RESERVED 16 364 #define TLS13_MT_FINISHED 20 365 #define TLS13_MT_CERTIFICATE_URL_RESERVED 21 366 #define TLS13_MT_CERTIFICATE_STATUS_RESERVED 22 367 #define TLS13_MT_SUPPLEMENTAL_DATA_RESERVED 23 368 #define TLS13_MT_KEY_UPDATE 24 369 #define TLS13_MT_MESSAGE_HASH 254 370 371 int tls13_handshake_msg_record(struct tls13_ctx *ctx); 372 int tls13_handshake_perform(struct tls13_ctx *ctx); 373 374 int tls13_client_init(struct tls13_ctx *ctx); 375 int tls13_server_init(struct tls13_ctx *ctx); 376 int tls13_client_connect(struct tls13_ctx *ctx); 377 int tls13_server_accept(struct tls13_ctx *ctx); 378 379 int tls13_client_hello_send(struct tls13_ctx *ctx, CBB *cbb); 380 int tls13_client_hello_sent(struct tls13_ctx *ctx); 381 int tls13_client_hello_recv(struct tls13_ctx *ctx, CBS *cbs); 382 int tls13_client_hello_retry_send(struct tls13_ctx *ctx, CBB *cbb); 383 int tls13_client_hello_retry_recv(struct tls13_ctx *ctx, CBS *cbs); 384 int tls13_client_end_of_early_data_send(struct tls13_ctx *ctx, CBB *cbb); 385 int tls13_client_end_of_early_data_recv(struct tls13_ctx *ctx, CBS *cbs); 386 int tls13_client_certificate_send(struct tls13_ctx *ctx, CBB *cbb); 387 int tls13_client_certificate_recv(struct tls13_ctx *ctx, CBS *cbs); 388 int tls13_client_certificate_verify_send(struct tls13_ctx *ctx, CBB *cbb); 389 int tls13_client_certificate_verify_recv(struct tls13_ctx *ctx, CBS *cbs); 390 int tls13_client_finished_recv(struct tls13_ctx *ctx, CBS *cbs); 391 int tls13_client_finished_send(struct tls13_ctx *ctx, CBB *cbb); 392 int tls13_client_finished_sent(struct tls13_ctx *ctx); 393 int tls13_server_hello_recv(struct tls13_ctx *ctx, CBS *cbs); 394 int tls13_server_hello_send(struct tls13_ctx *ctx, CBB *cbb); 395 int tls13_server_hello_sent(struct tls13_ctx *ctx); 396 int tls13_server_hello_retry_request_recv(struct tls13_ctx *ctx, CBS *cbs); 397 int tls13_server_hello_retry_request_send(struct tls13_ctx *ctx, CBB *cbb); 398 int tls13_server_hello_retry_request_sent(struct tls13_ctx *ctx); 399 int tls13_server_encrypted_extensions_recv(struct tls13_ctx *ctx, CBS *cbs); 400 int tls13_server_encrypted_extensions_send(struct tls13_ctx *ctx, CBB *cbb); 401 int tls13_server_certificate_recv(struct tls13_ctx *ctx, CBS *cbs); 402 int tls13_server_certificate_send(struct tls13_ctx *ctx, CBB *cbb); 403 int tls13_server_certificate_request_recv(struct tls13_ctx *ctx, CBS *cbs); 404 int tls13_server_certificate_request_send(struct tls13_ctx *ctx, CBB *cbb); 405 int tls13_server_certificate_verify_send(struct tls13_ctx *ctx, CBB *cbb); 406 int tls13_server_certificate_verify_recv(struct tls13_ctx *ctx, CBS *cbs); 407 int tls13_server_finished_recv(struct tls13_ctx *ctx, CBS *cbs); 408 int tls13_server_finished_send(struct tls13_ctx *ctx, CBB *cbb); 409 int tls13_server_finished_sent(struct tls13_ctx *ctx); 410 411 void tls13_error_clear(struct tls13_error *error); 412 int tls13_cert_add(struct tls13_ctx *ctx, CBB *cbb, X509 *cert, 413 int(*build_extensions)(SSL *s, uint16_t msg_type, CBB *cbb)); 414 415 int tls13_synthetic_handshake_message(struct tls13_ctx *ctx); 416 int tls13_clienthello_hash_init(struct tls13_ctx *ctx); 417 void tls13_clienthello_hash_clear(struct ssl_handshake_tls13_st *hs); 418 int tls13_clienthello_hash_update_bytes(struct tls13_ctx *ctx, void *data, 419 size_t len); 420 int tls13_clienthello_hash_update(struct tls13_ctx *ctx, CBS *cbs); 421 int tls13_clienthello_hash_finalize(struct tls13_ctx *ctx); 422 int tls13_clienthello_hash_validate(struct tls13_ctx *ctx); 423 424 int tls13_error_set(struct tls13_error *error, int code, int subcode, 425 const char *file, int line, const char *fmt, ...); 426 int tls13_error_setx(struct tls13_error *error, int code, int subcode, 427 const char *file, int line, const char *fmt, ...); 428 429 #define tls13_set_error(ctx, code, subcode, fmt, ...) \ 430 tls13_error_set(&(ctx)->error, (code), (subcode), __FILE__, __LINE__, \ 431 (fmt), __VA_ARGS__) 432 #define tls13_set_errorx(ctx, code, subcode, fmt, ...) \ 433 tls13_error_setx(&(ctx)->error, (code), (subcode), __FILE__, __LINE__, \ 434 (fmt), __VA_ARGS__) 435 436 int tls13_exporter(struct tls13_ctx *ctx, const uint8_t *label, size_t label_len, 437 const uint8_t *context_value, size_t context_value_len, uint8_t *out, 438 size_t out_len); 439 440 extern const uint8_t tls13_downgrade_12[8]; 441 extern const uint8_t tls13_downgrade_11[8]; 442 extern const uint8_t tls13_hello_retry_request_hash[32]; 443 extern const uint8_t tls13_cert_verify_pad[64]; 444 extern const uint8_t tls13_cert_client_verify_context[]; 445 extern const uint8_t tls13_cert_server_verify_context[]; 446 447 __END_HIDDEN_DECLS 448 449 #endif 450