1 /* $OpenBSD: tls13_internal.h,v 1.86.4.1 2021/02/03 07:06:14 tb 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 
85 typedef void (*tls13_alert_cb)(uint8_t _alert_desc, void *_cb_arg);
86 typedef ssize_t (*tls13_phh_recv_cb)(void *_cb_arg, CBS *_cbs);
87 typedef void (*tls13_phh_sent_cb)(void *_cb_arg);
88 typedef ssize_t (*tls13_read_cb)(void *_buf, size_t _buflen, void *_cb_arg);
89 typedef ssize_t (*tls13_write_cb)(const void *_buf, size_t _buflen,
90     void *_cb_arg);
91 typedef void (*tls13_handshake_message_cb)(void *_cb_arg);
92 typedef void (*tls13_info_cb)(void *_cb_arg, int _state, int _ret);
93 typedef int (*tls13_ocsp_status_cb)(void *_cb_arg);
94 
95 /*
96  * Buffers.
97  */
98 struct tls13_buffer;
99 
100 struct tls13_buffer *tls13_buffer_new(size_t init_size);
101 int tls13_buffer_set_data(struct tls13_buffer *buf, CBS *data);
102 void tls13_buffer_free(struct tls13_buffer *buf);
103 ssize_t tls13_buffer_extend(struct tls13_buffer *buf, size_t len,
104     tls13_read_cb read_cb, void *cb_arg);
105 void tls13_buffer_cbs(struct tls13_buffer *buf, CBS *cbs);
106 int tls13_buffer_finish(struct tls13_buffer *buf, uint8_t **out,
107     size_t *out_len);
108 
109 /*
110  * Secrets.
111  */
112 struct tls13_secret {
113 	uint8_t *data;
114 	size_t len;
115 };
116 
117 /* RFC 8446 Section 7.1  Page 92 */
118 struct tls13_secrets {
119 	const EVP_MD *digest;
120 	int resumption;
121 	int init_done;
122 	int early_done;
123 	int handshake_done;
124 	int schedule_done;
125 	int insecure; /* Set by tests */
126 	struct tls13_secret zeros;
127 	struct tls13_secret empty_hash;
128 	struct tls13_secret extracted_early;
129 	struct tls13_secret binder_key;
130 	struct tls13_secret client_early_traffic;
131 	struct tls13_secret early_exporter_master;
132 	struct tls13_secret derived_early;
133 	struct tls13_secret extracted_handshake;
134 	struct tls13_secret client_handshake_traffic;
135 	struct tls13_secret server_handshake_traffic;
136 	struct tls13_secret derived_handshake;
137 	struct tls13_secret extracted_master;
138 	struct tls13_secret client_application_traffic;
139 	struct tls13_secret server_application_traffic;
140 	struct tls13_secret exporter_master;
141 	struct tls13_secret resumption_master;
142 };
143 
144 struct tls13_secrets *tls13_secrets_create(const EVP_MD *digest,
145     int resumption);
146 void tls13_secrets_destroy(struct tls13_secrets *secrets);
147 
148 int tls13_hkdf_expand_label(struct tls13_secret *out, const EVP_MD *digest,
149     const struct tls13_secret *secret, const char *label,
150     const struct tls13_secret *context);
151 int tls13_hkdf_expand_label_with_length(struct tls13_secret *out,
152     const EVP_MD *digest, const struct tls13_secret *secret,
153     const uint8_t *label, size_t label_len, const struct tls13_secret *context);
154 
155 int tls13_derive_secret(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_derive_secret_with_label_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_early_secrets(struct tls13_secrets *secrets, uint8_t *psk,
163     size_t psk_len, const struct tls13_secret *context);
164 int tls13_derive_handshake_secrets(struct tls13_secrets *secrets,
165     const uint8_t *ecdhe, size_t ecdhe_len, const struct tls13_secret *context);
166 int tls13_derive_application_secrets(struct tls13_secrets *secrets,
167     const struct tls13_secret *context);
168 int tls13_update_client_traffic_secret(struct tls13_secrets *secrets);
169 int tls13_update_server_traffic_secret(struct tls13_secrets *secrets);
170 
171 /*
172  * Key shares.
173  */
174 struct tls13_key_share;
175 
176 struct tls13_key_share *tls13_key_share_new(uint16_t group_id);
177 struct tls13_key_share *tls13_key_share_new_nid(int nid);
178 void tls13_key_share_free(struct tls13_key_share *ks);
179 
180 uint16_t tls13_key_share_group(struct tls13_key_share *ks);
181 int tls13_key_share_peer_pkey(struct tls13_key_share *ks, EVP_PKEY *pkey);
182 int tls13_key_share_generate(struct tls13_key_share *ks);
183 int tls13_key_share_public(struct tls13_key_share *ks, CBB *cbb);
184 int tls13_key_share_peer_public(struct tls13_key_share *ks, uint16_t group,
185     CBS *cbs);
186 int tls13_key_share_derive(struct tls13_key_share *ks, uint8_t **shared_key,
187     size_t *shared_key_len);
188 
189 /*
190  * Record Layer.
191  */
192 struct tls13_record_layer;
193 
194 struct tls13_record_layer_callbacks {
195 	tls13_read_cb wire_read;
196 	tls13_write_cb wire_write;
197 	tls13_alert_cb alert_recv;
198 	tls13_alert_cb alert_sent;
199 	tls13_phh_recv_cb phh_recv;
200 	tls13_phh_sent_cb phh_sent;
201 };
202 
203 struct tls13_record_layer *tls13_record_layer_new(
204     const struct tls13_record_layer_callbacks *callbacks, void *cb_arg);
205 void tls13_record_layer_free(struct tls13_record_layer *rl);
206 void tls13_record_layer_allow_ccs(struct tls13_record_layer *rl, int allow);
207 void tls13_record_layer_allow_legacy_alerts(struct tls13_record_layer *rl, int allow);
208 void tls13_record_layer_rbuf(struct tls13_record_layer *rl, CBS *cbs);
209 void tls13_record_layer_set_aead(struct tls13_record_layer *rl,
210     const EVP_AEAD *aead);
211 void tls13_record_layer_set_hash(struct tls13_record_layer *rl,
212     const EVP_MD *hash);
213 void tls13_record_layer_set_legacy_version(struct tls13_record_layer *rl,
214     uint16_t version);
215 void tls13_record_layer_set_retry_after_phh(struct tls13_record_layer *rl, int retry);
216 void tls13_record_layer_handshake_completed(struct tls13_record_layer *rl);
217 int tls13_record_layer_set_read_traffic_key(struct tls13_record_layer *rl,
218     struct tls13_secret *read_key);
219 int tls13_record_layer_set_write_traffic_key(struct tls13_record_layer *rl,
220     struct tls13_secret *write_key);
221 ssize_t tls13_record_layer_send_pending(struct tls13_record_layer *rl);
222 ssize_t tls13_record_layer_phh(struct tls13_record_layer *rl, CBS *cbs);
223 
224 ssize_t tls13_read_handshake_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
225 ssize_t tls13_write_handshake_data(struct tls13_record_layer *rl, const uint8_t *buf,
226     size_t n);
227 ssize_t tls13_pending_application_data(struct tls13_record_layer *rl);
228 ssize_t tls13_peek_application_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
229 ssize_t tls13_read_application_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
230 ssize_t tls13_write_application_data(struct tls13_record_layer *rl, const uint8_t *buf,
231     size_t n);
232 
233 ssize_t tls13_send_alert(struct tls13_record_layer *rl, uint8_t alert_desc);
234 ssize_t tls13_send_dummy_ccs(struct tls13_record_layer *rl);
235 
236 /*
237  * Handshake Messages.
238  */
239 struct tls13_handshake_msg;
240 
241 struct tls13_handshake_msg *tls13_handshake_msg_new(void);
242 void tls13_handshake_msg_free(struct tls13_handshake_msg *msg);
243 void tls13_handshake_msg_data(struct tls13_handshake_msg *msg, CBS *cbs);
244 int tls13_handshake_msg_set_buffer(struct tls13_handshake_msg *msg, CBS *cbs);
245 uint8_t tls13_handshake_msg_type(struct tls13_handshake_msg *msg);
246 int tls13_handshake_msg_content(struct tls13_handshake_msg *msg, CBS *cbs);
247 int tls13_handshake_msg_start(struct tls13_handshake_msg *msg, CBB *body,
248     uint8_t msg_type);
249 int tls13_handshake_msg_finish(struct tls13_handshake_msg *msg);
250 int tls13_handshake_msg_recv(struct tls13_handshake_msg *msg,
251     struct tls13_record_layer *rl);
252 int tls13_handshake_msg_send(struct tls13_handshake_msg *msg,
253     struct tls13_record_layer *rl);
254 
255 struct tls13_handshake_stage {
256 	uint8_t	hs_type;
257 	uint8_t	message_number;
258 };
259 
260 struct ssl_handshake_tls13_st;
261 
262 struct tls13_error {
263 	int code;
264 	int subcode;
265 	int errnum;
266 	const char *file;
267 	int line;
268 	char *msg;
269 };
270 
271 struct tls13_ctx {
272 	struct tls13_error error;
273 
274 	SSL *ssl;
275 	struct ssl_handshake_tls13_st *hs;
276 	uint8_t	mode;
277 	struct tls13_handshake_stage handshake_stage;
278 	int handshake_started;
279 	int handshake_completed;
280 	int middlebox_compat;
281 	int send_dummy_ccs;
282 	int send_dummy_ccs_after;
283 
284 	int close_notify_sent;
285 	int close_notify_recv;
286 
287 	const EVP_AEAD *aead;
288 	const EVP_MD *hash;
289 
290 	struct tls13_record_layer *rl;
291 	struct tls13_handshake_msg *hs_msg;
292 	uint8_t key_update_request;
293 	uint8_t alert;
294 	int phh_count;
295 	time_t phh_last_seen;
296 
297 	tls13_handshake_message_cb handshake_message_sent_cb;
298 	tls13_handshake_message_cb handshake_message_recv_cb;
299 	tls13_info_cb info_cb;
300 	tls13_ocsp_status_cb ocsp_status_recv_cb;
301 };
302 #ifndef TLS13_PHH_LIMIT_TIME
303 #define TLS13_PHH_LIMIT_TIME 3600
304 #endif
305 #ifndef TLS13_PHH_LIMIT
306 #define TLS13_PHH_LIMIT 100
307 #endif
308 
309 struct tls13_ctx *tls13_ctx_new(int mode);
310 void tls13_ctx_free(struct tls13_ctx *ctx);
311 
312 const EVP_AEAD *tls13_cipher_aead(const SSL_CIPHER *cipher);
313 const EVP_MD *tls13_cipher_hash(const SSL_CIPHER *cipher);
314 
315 /*
316  * Legacy interfaces.
317  */
318 int tls13_use_legacy_client(struct tls13_ctx *ctx);
319 int tls13_use_legacy_server(struct tls13_ctx *ctx);
320 int tls13_legacy_accept(SSL *ssl);
321 int tls13_legacy_connect(SSL *ssl);
322 int tls13_legacy_return_code(SSL *ssl, ssize_t ret);
323 ssize_t tls13_legacy_wire_read_cb(void *buf, size_t n, void *arg);
324 ssize_t tls13_legacy_wire_write_cb(const void *buf, size_t n, void *arg);
325 int tls13_legacy_pending(const SSL *ssl);
326 int tls13_legacy_read_bytes(SSL *ssl, int type, unsigned char *buf, int len,
327     int peek);
328 int tls13_legacy_write_bytes(SSL *ssl, int type, const void *buf, int len);
329 int tls13_legacy_shutdown(SSL *ssl);
330 int tls13_legacy_servername_process(struct tls13_ctx *ctx, uint8_t *alert);
331 
332 /*
333  * Message Types - RFC 8446, Section B.3.
334  *
335  * Values listed as "_RESERVED" were used in previous versions of TLS and are
336  * listed here for completeness.  TLS 1.3 implementations MUST NOT send them but
337  * might receive them from older TLS implementations.
338  */
339 #define	TLS13_MT_HELLO_REQUEST_RESERVED		0
340 #define	TLS13_MT_CLIENT_HELLO			1
341 #define	TLS13_MT_SERVER_HELLO			2
342 #define	TLS13_MT_HELLO_VERIFY_REQUEST_RESERVED	3
343 #define	TLS13_MT_NEW_SESSION_TICKET		4
344 #define	TLS13_MT_END_OF_EARLY_DATA		5
345 #define	TLS13_MT_HELLO_RETRY_REQUEST_RESERVED	6
346 #define	TLS13_MT_ENCRYPTED_EXTENSIONS		8
347 #define	TLS13_MT_CERTIFICATE			11
348 #define	TLS13_MT_SERVER_KEY_EXCHANGE_RESERVED	12
349 #define	TLS13_MT_CERTIFICATE_REQUEST		13
350 #define	TLS13_MT_SERVER_HELLO_DONE_RESERVED	14
351 #define	TLS13_MT_CERTIFICATE_VERIFY		15
352 #define	TLS13_MT_CLIENT_KEY_EXCHANGE_RESERVED	16
353 #define	TLS13_MT_FINISHED			20
354 #define	TLS13_MT_CERTIFICATE_URL_RESERVED	21
355 #define	TLS13_MT_CERTIFICATE_STATUS_RESERVED	22
356 #define	TLS13_MT_SUPPLEMENTAL_DATA_RESERVED	23
357 #define	TLS13_MT_KEY_UPDATE			24
358 #define	TLS13_MT_MESSAGE_HASH			254
359 
360 int tls13_handshake_msg_record(struct tls13_ctx *ctx);
361 int tls13_handshake_perform(struct tls13_ctx *ctx);
362 
363 int tls13_client_init(struct tls13_ctx *ctx);
364 int tls13_server_init(struct tls13_ctx *ctx);
365 int tls13_client_connect(struct tls13_ctx *ctx);
366 int tls13_server_accept(struct tls13_ctx *ctx);
367 
368 int tls13_client_hello_send(struct tls13_ctx *ctx, CBB *cbb);
369 int tls13_client_hello_sent(struct tls13_ctx *ctx);
370 int tls13_client_hello_recv(struct tls13_ctx *ctx, CBS *cbs);
371 int tls13_client_hello_retry_send(struct tls13_ctx *ctx, CBB *cbb);
372 int tls13_client_hello_retry_recv(struct tls13_ctx *ctx, CBS *cbs);
373 int tls13_client_end_of_early_data_send(struct tls13_ctx *ctx, CBB *cbb);
374 int tls13_client_end_of_early_data_recv(struct tls13_ctx *ctx, CBS *cbs);
375 int tls13_client_certificate_send(struct tls13_ctx *ctx, CBB *cbb);
376 int tls13_client_certificate_recv(struct tls13_ctx *ctx, CBS *cbs);
377 int tls13_client_certificate_verify_send(struct tls13_ctx *ctx, CBB *cbb);
378 int tls13_client_certificate_verify_recv(struct tls13_ctx *ctx, CBS *cbs);
379 int tls13_client_finished_recv(struct tls13_ctx *ctx, CBS *cbs);
380 int tls13_client_finished_send(struct tls13_ctx *ctx, CBB *cbb);
381 int tls13_client_finished_sent(struct tls13_ctx *ctx);
382 int tls13_server_hello_recv(struct tls13_ctx *ctx, CBS *cbs);
383 int tls13_server_hello_send(struct tls13_ctx *ctx, CBB *cbb);
384 int tls13_server_hello_sent(struct tls13_ctx *ctx);
385 int tls13_server_hello_retry_request_recv(struct tls13_ctx *ctx, CBS *cbs);
386 int tls13_server_hello_retry_request_send(struct tls13_ctx *ctx, CBB *cbb);
387 int tls13_server_hello_retry_request_sent(struct tls13_ctx *ctx);
388 int tls13_server_encrypted_extensions_recv(struct tls13_ctx *ctx, CBS *cbs);
389 int tls13_server_encrypted_extensions_send(struct tls13_ctx *ctx, CBB *cbb);
390 int tls13_server_certificate_recv(struct tls13_ctx *ctx, CBS *cbs);
391 int tls13_server_certificate_send(struct tls13_ctx *ctx, CBB *cbb);
392 int tls13_server_certificate_request_recv(struct tls13_ctx *ctx, CBS *cbs);
393 int tls13_server_certificate_request_send(struct tls13_ctx *ctx, CBB *cbb);
394 int tls13_server_certificate_verify_send(struct tls13_ctx *ctx, CBB *cbb);
395 int tls13_server_certificate_verify_recv(struct tls13_ctx *ctx, CBS *cbs);
396 int tls13_server_finished_recv(struct tls13_ctx *ctx, CBS *cbs);
397 int tls13_server_finished_send(struct tls13_ctx *ctx, CBB *cbb);
398 int tls13_server_finished_sent(struct tls13_ctx *ctx);
399 
400 void tls13_error_clear(struct tls13_error *error);
401 int tls13_cert_add(struct tls13_ctx *ctx, CBB *cbb, X509 *cert,
402     int(*build_extensions)(SSL *s, uint16_t msg_type, CBB *cbb));
403 
404 int tls13_synthetic_handshake_message(struct tls13_ctx *ctx);
405 int tls13_clienthello_hash_init(struct tls13_ctx *ctx);
406 void tls13_clienthello_hash_clear(struct ssl_handshake_tls13_st *hs);
407 int tls13_clienthello_hash_update_bytes(struct tls13_ctx *ctx, void *data,
408     size_t len);
409 int tls13_clienthello_hash_update(struct tls13_ctx *ctx, CBS *cbs);
410 int tls13_clienthello_hash_finalize(struct tls13_ctx *ctx);
411 int tls13_clienthello_hash_validate(struct tls13_ctx *ctx);
412 
413 int tls13_error_set(struct tls13_error *error, int code, int subcode,
414     const char *file, int line, const char *fmt, ...);
415 int tls13_error_setx(struct tls13_error *error, int code, int subcode,
416     const char *file, int line, const char *fmt, ...);
417 
418 #define tls13_set_error(ctx, code, subcode, fmt, ...) \
419 	tls13_error_set(&(ctx)->error, (code), (subcode), __FILE__, __LINE__, \
420 	    (fmt), __VA_ARGS__)
421 #define tls13_set_errorx(ctx, code, subcode, fmt, ...) \
422 	tls13_error_setx(&(ctx)->error, (code), (subcode), __FILE__, __LINE__, \
423 	    (fmt), __VA_ARGS__)
424 
425 int tls13_exporter(struct tls13_ctx *ctx, const uint8_t *label, size_t label_len,
426     const uint8_t *context_value, size_t context_value_len, uint8_t *out,
427     size_t out_len);
428 
429 extern const uint8_t tls13_downgrade_12[8];
430 extern const uint8_t tls13_downgrade_11[8];
431 extern const uint8_t tls13_hello_retry_request_hash[32];
432 extern const uint8_t tls13_cert_verify_pad[64];
433 extern const uint8_t tls13_cert_client_verify_context[];
434 extern const uint8_t tls13_cert_server_verify_context[];
435 
436 __END_HIDDEN_DECLS
437 
438 #endif
439