xref: /openbsd-src/lib/libssl/tls13_internal.h (revision 4e1ee0786f11cc571bd0be17d38e46f635c719fc)
1 /* $OpenBSD: tls13_internal.h,v 1.95 2021/10/23 13:12:14 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 #include "tls_internal.h"
28 
29 __BEGIN_HIDDEN_DECLS
30 
31 #define TLS13_HS_CLIENT			1
32 #define TLS13_HS_SERVER			2
33 
34 #define TLS13_IO_SUCCESS		 1
35 #define TLS13_IO_EOF			 0
36 #define TLS13_IO_FAILURE		-1
37 #define TLS13_IO_ALERT			-2
38 #define TLS13_IO_WANT_POLLIN		-3
39 #define TLS13_IO_WANT_POLLOUT		-4
40 #define TLS13_IO_WANT_RETRY		-5 /* Retry the previous call immediately. */
41 #define TLS13_IO_USE_LEGACY		-6
42 #define TLS13_IO_RECORD_VERSION		-7
43 #define TLS13_IO_RECORD_OVERFLOW	-8
44 
45 #define TLS13_ERR_VERIFY_FAILED		16
46 #define TLS13_ERR_HRR_FAILED		17
47 #define TLS13_ERR_TRAILING_DATA		18
48 #define TLS13_ERR_NO_SHARED_CIPHER	19
49 #define TLS13_ERR_NO_CERTIFICATE	20
50 #define TLS13_ERR_NO_PEER_CERTIFICATE	21
51 
52 #define TLS13_ALERT_LEVEL_WARNING			1
53 #define TLS13_ALERT_LEVEL_FATAL				2
54 
55 #define TLS13_ALERT_CLOSE_NOTIFY			0
56 #define TLS13_ALERT_UNEXPECTED_MESSAGE			10
57 #define TLS13_ALERT_BAD_RECORD_MAC			20
58 #define TLS13_ALERT_RECORD_OVERFLOW			22
59 #define TLS13_ALERT_HANDSHAKE_FAILURE			40
60 #define TLS13_ALERT_BAD_CERTIFICATE			42
61 #define TLS13_ALERT_UNSUPPORTED_CERTIFICATE		43
62 #define TLS13_ALERT_CERTIFICATE_REVOKED			44
63 #define TLS13_ALERT_CERTIFICATE_EXPIRED			45
64 #define TLS13_ALERT_CERTIFICATE_UNKNOWN			46
65 #define TLS13_ALERT_ILLEGAL_PARAMETER			47
66 #define TLS13_ALERT_UNKNOWN_CA				48
67 #define TLS13_ALERT_ACCESS_DENIED			49
68 #define TLS13_ALERT_DECODE_ERROR			50
69 #define TLS13_ALERT_DECRYPT_ERROR			51
70 #define TLS13_ALERT_PROTOCOL_VERSION			70
71 #define TLS13_ALERT_INSUFFICIENT_SECURITY		71
72 #define TLS13_ALERT_INTERNAL_ERROR			80
73 #define TLS13_ALERT_INAPPROPRIATE_FALLBACK		86
74 #define TLS13_ALERT_USER_CANCELED			90
75 #define TLS13_ALERT_MISSING_EXTENSION			109
76 #define TLS13_ALERT_UNSUPPORTED_EXTENSION		110
77 #define TLS13_ALERT_UNRECOGNIZED_NAME			112
78 #define TLS13_ALERT_BAD_CERTIFICATE_STATUS_RESPONSE	113
79 #define TLS13_ALERT_UNKNOWN_PSK_IDENTITY		115
80 #define TLS13_ALERT_CERTIFICATE_REQUIRED		116
81 #define TLS13_ALERT_NO_APPLICATION_PROTOCOL		120
82 
83 #define TLS13_INFO_HANDSHAKE_STARTED			SSL_CB_HANDSHAKE_START
84 #define TLS13_INFO_HANDSHAKE_COMPLETED			SSL_CB_HANDSHAKE_DONE
85 #define TLS13_INFO_ACCEPT_LOOP				SSL_CB_ACCEPT_LOOP
86 #define TLS13_INFO_CONNECT_LOOP				SSL_CB_CONNECT_LOOP
87 #define TLS13_INFO_ACCEPT_EXIT				SSL_CB_ACCEPT_EXIT
88 #define TLS13_INFO_CONNECT_EXIT				SSL_CB_CONNECT_EXIT
89 
90 typedef void (*tls13_alert_cb)(uint8_t _alert_desc, void *_cb_arg);
91 typedef ssize_t (*tls13_phh_recv_cb)(void *_cb_arg, CBS *_cbs);
92 typedef void (*tls13_phh_sent_cb)(void *_cb_arg);
93 typedef void (*tls13_handshake_message_cb)(void *_cb_arg);
94 typedef void (*tls13_info_cb)(void *_cb_arg, int _state, int _ret);
95 typedef int (*tls13_ocsp_status_cb)(void *_cb_arg);
96 
97 /*
98  * Secrets.
99  */
100 struct tls13_secret {
101 	uint8_t *data;
102 	size_t len;
103 };
104 
105 /* RFC 8446 Section 7.1  Page 92 */
106 struct tls13_secrets {
107 	const EVP_MD *digest;
108 	int resumption;
109 	int init_done;
110 	int early_done;
111 	int handshake_done;
112 	int schedule_done;
113 	int insecure; /* Set by tests */
114 	struct tls13_secret zeros;
115 	struct tls13_secret empty_hash;
116 	struct tls13_secret extracted_early;
117 	struct tls13_secret binder_key;
118 	struct tls13_secret client_early_traffic;
119 	struct tls13_secret early_exporter_master;
120 	struct tls13_secret derived_early;
121 	struct tls13_secret extracted_handshake;
122 	struct tls13_secret client_handshake_traffic;
123 	struct tls13_secret server_handshake_traffic;
124 	struct tls13_secret derived_handshake;
125 	struct tls13_secret extracted_master;
126 	struct tls13_secret client_application_traffic;
127 	struct tls13_secret server_application_traffic;
128 	struct tls13_secret exporter_master;
129 	struct tls13_secret resumption_master;
130 };
131 
132 int tls13_secret_init(struct tls13_secret *secret, size_t len);
133 void tls13_secret_cleanup(struct tls13_secret *secret);
134 struct tls13_secrets *tls13_secrets_create(const EVP_MD *digest,
135     int resumption);
136 void tls13_secrets_destroy(struct tls13_secrets *secrets);
137 
138 int tls13_hkdf_expand_label(struct tls13_secret *out, const EVP_MD *digest,
139     const struct tls13_secret *secret, const char *label,
140     const struct tls13_secret *context);
141 int tls13_hkdf_expand_label_with_length(struct tls13_secret *out,
142     const EVP_MD *digest, const struct tls13_secret *secret,
143     const uint8_t *label, size_t label_len, const struct tls13_secret *context);
144 
145 int tls13_derive_secret(struct tls13_secret *out, const EVP_MD *digest,
146     const struct tls13_secret *secret, const char *label,
147     const struct tls13_secret *context);
148 int tls13_derive_secret_with_label_length(struct tls13_secret *out,
149     const EVP_MD *digest, const struct tls13_secret *secret,
150     const uint8_t *label, size_t label_len, const struct tls13_secret *context);
151 
152 int tls13_derive_early_secrets(struct tls13_secrets *secrets, uint8_t *psk,
153     size_t psk_len, const struct tls13_secret *context);
154 int tls13_derive_handshake_secrets(struct tls13_secrets *secrets,
155     const uint8_t *ecdhe, size_t ecdhe_len, const struct tls13_secret *context);
156 int tls13_derive_application_secrets(struct tls13_secrets *secrets,
157     const struct tls13_secret *context);
158 int tls13_update_client_traffic_secret(struct tls13_secrets *secrets);
159 int tls13_update_server_traffic_secret(struct tls13_secrets *secrets);
160 
161 /*
162  * Key shares.
163  */
164 struct tls13_key_share;
165 
166 struct tls13_key_share *tls13_key_share_new(uint16_t group_id);
167 struct tls13_key_share *tls13_key_share_new_nid(int nid);
168 void tls13_key_share_free(struct tls13_key_share *ks);
169 
170 uint16_t tls13_key_share_group(struct tls13_key_share *ks);
171 int tls13_key_share_peer_pkey(struct tls13_key_share *ks, EVP_PKEY *pkey);
172 int tls13_key_share_generate(struct tls13_key_share *ks);
173 int tls13_key_share_public(struct tls13_key_share *ks, CBB *cbb);
174 int tls13_key_share_peer_public(struct tls13_key_share *ks, uint16_t group,
175     CBS *cbs);
176 int tls13_key_share_derive(struct tls13_key_share *ks, uint8_t **shared_key,
177     size_t *shared_key_len);
178 
179 /*
180  * Record Layer.
181  */
182 struct tls13_record_layer;
183 
184 struct tls13_record_layer_callbacks {
185 	tls_read_cb wire_read;
186 	tls_write_cb wire_write;
187 	tls_flush_cb wire_flush;
188 	tls13_alert_cb alert_recv;
189 	tls13_alert_cb alert_sent;
190 	tls13_phh_recv_cb phh_recv;
191 	tls13_phh_sent_cb phh_sent;
192 };
193 
194 struct tls13_record_layer *tls13_record_layer_new(
195     const struct tls13_record_layer_callbacks *callbacks, void *cb_arg);
196 void tls13_record_layer_free(struct tls13_record_layer *rl);
197 void tls13_record_layer_allow_ccs(struct tls13_record_layer *rl, int allow);
198 void tls13_record_layer_allow_legacy_alerts(struct tls13_record_layer *rl, int allow);
199 void tls13_record_layer_rcontent(struct tls13_record_layer *rl, CBS *cbs);
200 void tls13_record_layer_set_aead(struct tls13_record_layer *rl,
201     const EVP_AEAD *aead);
202 void tls13_record_layer_set_hash(struct tls13_record_layer *rl,
203     const EVP_MD *hash);
204 void tls13_record_layer_set_legacy_version(struct tls13_record_layer *rl,
205     uint16_t version);
206 void tls13_record_layer_set_retry_after_phh(struct tls13_record_layer *rl, int retry);
207 void tls13_record_layer_handshake_completed(struct tls13_record_layer *rl);
208 int tls13_record_layer_set_read_traffic_key(struct tls13_record_layer *rl,
209     struct tls13_secret *read_key);
210 int tls13_record_layer_set_write_traffic_key(struct tls13_record_layer *rl,
211     struct tls13_secret *write_key);
212 ssize_t tls13_record_layer_send_pending(struct tls13_record_layer *rl);
213 ssize_t tls13_record_layer_phh(struct tls13_record_layer *rl, CBS *cbs);
214 ssize_t tls13_record_layer_flush(struct tls13_record_layer *rl);
215 
216 ssize_t tls13_read_handshake_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
217 ssize_t tls13_write_handshake_data(struct tls13_record_layer *rl, const uint8_t *buf,
218     size_t n);
219 ssize_t tls13_pending_application_data(struct tls13_record_layer *rl);
220 ssize_t tls13_peek_application_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
221 ssize_t tls13_read_application_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
222 ssize_t tls13_write_application_data(struct tls13_record_layer *rl, const uint8_t *buf,
223     size_t n);
224 
225 ssize_t tls13_send_alert(struct tls13_record_layer *rl, uint8_t alert_desc);
226 ssize_t tls13_send_dummy_ccs(struct tls13_record_layer *rl);
227 
228 /*
229  * Handshake Messages.
230  */
231 struct tls13_handshake_msg;
232 
233 struct tls13_handshake_msg *tls13_handshake_msg_new(void);
234 void tls13_handshake_msg_free(struct tls13_handshake_msg *msg);
235 void tls13_handshake_msg_data(struct tls13_handshake_msg *msg, CBS *cbs);
236 int tls13_handshake_msg_set_buffer(struct tls13_handshake_msg *msg, CBS *cbs);
237 uint8_t tls13_handshake_msg_type(struct tls13_handshake_msg *msg);
238 int tls13_handshake_msg_content(struct tls13_handshake_msg *msg, CBS *cbs);
239 int tls13_handshake_msg_start(struct tls13_handshake_msg *msg, CBB *body,
240     uint8_t msg_type);
241 int tls13_handshake_msg_finish(struct tls13_handshake_msg *msg);
242 int tls13_handshake_msg_recv(struct tls13_handshake_msg *msg,
243     struct tls13_record_layer *rl);
244 int tls13_handshake_msg_send(struct tls13_handshake_msg *msg,
245     struct tls13_record_layer *rl);
246 
247 struct tls13_handshake_stage {
248 	uint8_t	hs_type;
249 	uint8_t	message_number;
250 };
251 
252 struct ssl_handshake_tls13_st;
253 
254 struct tls13_error {
255 	int code;
256 	int subcode;
257 	int errnum;
258 	const char *file;
259 	int line;
260 	char *msg;
261 };
262 
263 struct tls13_ctx {
264 	struct tls13_error error;
265 
266 	SSL *ssl;
267 	struct ssl_handshake_st *hs;
268 	uint8_t	mode;
269 	struct tls13_handshake_stage handshake_stage;
270 	int handshake_started;
271 	int handshake_completed;
272 	int need_flush;
273 	int middlebox_compat;
274 	int send_dummy_ccs;
275 	int send_dummy_ccs_after;
276 
277 	int close_notify_sent;
278 	int close_notify_recv;
279 
280 	const EVP_AEAD *aead;
281 	const EVP_MD *hash;
282 
283 	struct tls13_record_layer *rl;
284 	struct tls13_handshake_msg *hs_msg;
285 	uint8_t key_update_request;
286 	uint8_t alert;
287 	int phh_count;
288 	time_t phh_last_seen;
289 
290 	tls13_handshake_message_cb handshake_message_sent_cb;
291 	tls13_handshake_message_cb handshake_message_recv_cb;
292 	tls13_info_cb info_cb;
293 	tls13_ocsp_status_cb ocsp_status_recv_cb;
294 };
295 #ifndef TLS13_PHH_LIMIT_TIME
296 #define TLS13_PHH_LIMIT_TIME 3600
297 #endif
298 #ifndef TLS13_PHH_LIMIT
299 #define TLS13_PHH_LIMIT 100
300 #endif
301 
302 struct tls13_ctx *tls13_ctx_new(int mode);
303 void tls13_ctx_free(struct tls13_ctx *ctx);
304 
305 const EVP_AEAD *tls13_cipher_aead(const SSL_CIPHER *cipher);
306 const EVP_MD *tls13_cipher_hash(const SSL_CIPHER *cipher);
307 
308 /*
309  * Legacy interfaces.
310  */
311 int tls13_use_legacy_client(struct tls13_ctx *ctx);
312 int tls13_use_legacy_server(struct tls13_ctx *ctx);
313 int tls13_legacy_accept(SSL *ssl);
314 int tls13_legacy_connect(SSL *ssl);
315 int tls13_legacy_return_code(SSL *ssl, ssize_t ret);
316 ssize_t tls13_legacy_wire_read_cb(void *buf, size_t n, void *arg);
317 ssize_t tls13_legacy_wire_write_cb(const void *buf, size_t n, void *arg);
318 ssize_t tls13_legacy_wire_flush_cb(void *arg);
319 int tls13_legacy_pending(const SSL *ssl);
320 int tls13_legacy_read_bytes(SSL *ssl, int type, unsigned char *buf, int len,
321     int peek);
322 int tls13_legacy_write_bytes(SSL *ssl, int type, const void *buf, int len);
323 int tls13_legacy_shutdown(SSL *ssl);
324 int tls13_legacy_servername_process(struct tls13_ctx *ctx, uint8_t *alert);
325 
326 /*
327  * Message Types - RFC 8446, Section B.3.
328  *
329  * Values listed as "_RESERVED" were used in previous versions of TLS and are
330  * listed here for completeness.  TLS 1.3 implementations MUST NOT send them but
331  * might receive them from older TLS implementations.
332  */
333 #define	TLS13_MT_HELLO_REQUEST_RESERVED		0
334 #define	TLS13_MT_CLIENT_HELLO			1
335 #define	TLS13_MT_SERVER_HELLO			2
336 #define	TLS13_MT_HELLO_VERIFY_REQUEST_RESERVED	3
337 #define	TLS13_MT_NEW_SESSION_TICKET		4
338 #define	TLS13_MT_END_OF_EARLY_DATA		5
339 #define	TLS13_MT_HELLO_RETRY_REQUEST_RESERVED	6
340 #define	TLS13_MT_ENCRYPTED_EXTENSIONS		8
341 #define	TLS13_MT_CERTIFICATE			11
342 #define	TLS13_MT_SERVER_KEY_EXCHANGE_RESERVED	12
343 #define	TLS13_MT_CERTIFICATE_REQUEST		13
344 #define	TLS13_MT_SERVER_HELLO_DONE_RESERVED	14
345 #define	TLS13_MT_CERTIFICATE_VERIFY		15
346 #define	TLS13_MT_CLIENT_KEY_EXCHANGE_RESERVED	16
347 #define	TLS13_MT_FINISHED			20
348 #define	TLS13_MT_CERTIFICATE_URL_RESERVED	21
349 #define	TLS13_MT_CERTIFICATE_STATUS_RESERVED	22
350 #define	TLS13_MT_SUPPLEMENTAL_DATA_RESERVED	23
351 #define	TLS13_MT_KEY_UPDATE			24
352 #define	TLS13_MT_MESSAGE_HASH			254
353 
354 int tls13_handshake_msg_record(struct tls13_ctx *ctx);
355 int tls13_handshake_perform(struct tls13_ctx *ctx);
356 
357 int tls13_client_init(struct tls13_ctx *ctx);
358 int tls13_server_init(struct tls13_ctx *ctx);
359 int tls13_client_connect(struct tls13_ctx *ctx);
360 int tls13_server_accept(struct tls13_ctx *ctx);
361 
362 int tls13_client_hello_send(struct tls13_ctx *ctx, CBB *cbb);
363 int tls13_client_hello_sent(struct tls13_ctx *ctx);
364 int tls13_client_hello_recv(struct tls13_ctx *ctx, CBS *cbs);
365 int tls13_client_hello_retry_send(struct tls13_ctx *ctx, CBB *cbb);
366 int tls13_client_hello_retry_recv(struct tls13_ctx *ctx, CBS *cbs);
367 int tls13_client_end_of_early_data_send(struct tls13_ctx *ctx, CBB *cbb);
368 int tls13_client_end_of_early_data_recv(struct tls13_ctx *ctx, CBS *cbs);
369 int tls13_client_certificate_send(struct tls13_ctx *ctx, CBB *cbb);
370 int tls13_client_certificate_recv(struct tls13_ctx *ctx, CBS *cbs);
371 int tls13_client_certificate_verify_send(struct tls13_ctx *ctx, CBB *cbb);
372 int tls13_client_certificate_verify_recv(struct tls13_ctx *ctx, CBS *cbs);
373 int tls13_client_finished_recv(struct tls13_ctx *ctx, CBS *cbs);
374 int tls13_client_finished_send(struct tls13_ctx *ctx, CBB *cbb);
375 int tls13_client_finished_sent(struct tls13_ctx *ctx);
376 int tls13_server_hello_recv(struct tls13_ctx *ctx, CBS *cbs);
377 int tls13_server_hello_send(struct tls13_ctx *ctx, CBB *cbb);
378 int tls13_server_hello_sent(struct tls13_ctx *ctx);
379 int tls13_server_hello_retry_request_recv(struct tls13_ctx *ctx, CBS *cbs);
380 int tls13_server_hello_retry_request_send(struct tls13_ctx *ctx, CBB *cbb);
381 int tls13_server_hello_retry_request_sent(struct tls13_ctx *ctx);
382 int tls13_server_encrypted_extensions_recv(struct tls13_ctx *ctx, CBS *cbs);
383 int tls13_server_encrypted_extensions_send(struct tls13_ctx *ctx, CBB *cbb);
384 int tls13_server_certificate_recv(struct tls13_ctx *ctx, CBS *cbs);
385 int tls13_server_certificate_send(struct tls13_ctx *ctx, CBB *cbb);
386 int tls13_server_certificate_request_recv(struct tls13_ctx *ctx, CBS *cbs);
387 int tls13_server_certificate_request_send(struct tls13_ctx *ctx, CBB *cbb);
388 int tls13_server_certificate_verify_send(struct tls13_ctx *ctx, CBB *cbb);
389 int tls13_server_certificate_verify_recv(struct tls13_ctx *ctx, CBS *cbs);
390 int tls13_server_finished_recv(struct tls13_ctx *ctx, CBS *cbs);
391 int tls13_server_finished_send(struct tls13_ctx *ctx, CBB *cbb);
392 int tls13_server_finished_sent(struct tls13_ctx *ctx);
393 
394 void tls13_error_clear(struct tls13_error *error);
395 int tls13_cert_add(struct tls13_ctx *ctx, CBB *cbb, X509 *cert,
396     int(*build_extensions)(SSL *s, uint16_t msg_type, CBB *cbb));
397 
398 int tls13_synthetic_handshake_message(struct tls13_ctx *ctx);
399 int tls13_clienthello_hash_init(struct tls13_ctx *ctx);
400 void tls13_clienthello_hash_clear(struct ssl_handshake_tls13_st *hs);
401 int tls13_clienthello_hash_update_bytes(struct tls13_ctx *ctx, void *data,
402     size_t len);
403 int tls13_clienthello_hash_update(struct tls13_ctx *ctx, CBS *cbs);
404 int tls13_clienthello_hash_finalize(struct tls13_ctx *ctx);
405 int tls13_clienthello_hash_validate(struct tls13_ctx *ctx);
406 
407 int tls13_error_set(struct tls13_error *error, int code, int subcode,
408     const char *file, int line, const char *fmt, ...);
409 int tls13_error_setx(struct tls13_error *error, int code, int subcode,
410     const char *file, int line, const char *fmt, ...);
411 
412 #define tls13_set_error(ctx, code, subcode, fmt, ...) \
413 	tls13_error_set(&(ctx)->error, (code), (subcode), __FILE__, __LINE__, \
414 	    (fmt), __VA_ARGS__)
415 #define tls13_set_errorx(ctx, code, subcode, fmt, ...) \
416 	tls13_error_setx(&(ctx)->error, (code), (subcode), __FILE__, __LINE__, \
417 	    (fmt), __VA_ARGS__)
418 
419 int tls13_exporter(struct tls13_ctx *ctx, const uint8_t *label, size_t label_len,
420     const uint8_t *context_value, size_t context_value_len, uint8_t *out,
421     size_t out_len);
422 
423 extern const uint8_t tls13_downgrade_12[8];
424 extern const uint8_t tls13_downgrade_11[8];
425 extern const uint8_t tls13_hello_retry_request_hash[32];
426 extern const uint8_t tls13_cert_verify_pad[64];
427 extern const uint8_t tls13_cert_client_verify_context[];
428 extern const uint8_t tls13_cert_server_verify_context[];
429 
430 __END_HIDDEN_DECLS
431 
432 #endif
433