1 /* $OpenBSD: tls13_internal.h,v 1.86 2020/07/30 16:23:17 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 
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 	tls13_read_cb wire_read;
186 	tls13_write_cb wire_write;
187 	tls13_alert_cb alert_recv;
188 	tls13_alert_cb alert_sent;
189 	tls13_phh_recv_cb phh_recv;
190 	tls13_phh_sent_cb phh_sent;
191 };
192 
193 struct tls13_record_layer *tls13_record_layer_new(
194     const struct tls13_record_layer_callbacks *callbacks, void *cb_arg);
195 void tls13_record_layer_free(struct tls13_record_layer *rl);
196 void tls13_record_layer_allow_ccs(struct tls13_record_layer *rl, int allow);
197 void tls13_record_layer_allow_legacy_alerts(struct tls13_record_layer *rl, int allow);
198 void tls13_record_layer_rbuf(struct tls13_record_layer *rl, CBS *cbs);
199 void tls13_record_layer_set_aead(struct tls13_record_layer *rl,
200     const EVP_AEAD *aead);
201 void tls13_record_layer_set_hash(struct tls13_record_layer *rl,
202     const EVP_MD *hash);
203 void tls13_record_layer_set_legacy_version(struct tls13_record_layer *rl,
204     uint16_t version);
205 void tls13_record_layer_set_retry_after_phh(struct tls13_record_layer *rl, int retry);
206 void tls13_record_layer_handshake_completed(struct tls13_record_layer *rl);
207 int tls13_record_layer_set_read_traffic_key(struct tls13_record_layer *rl,
208     struct tls13_secret *read_key);
209 int tls13_record_layer_set_write_traffic_key(struct tls13_record_layer *rl,
210     struct tls13_secret *write_key);
211 ssize_t tls13_record_layer_send_pending(struct tls13_record_layer *rl);
212 ssize_t tls13_record_layer_phh(struct tls13_record_layer *rl, CBS *cbs);
213 
214 ssize_t tls13_read_handshake_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
215 ssize_t tls13_write_handshake_data(struct tls13_record_layer *rl, const uint8_t *buf,
216     size_t n);
217 ssize_t tls13_pending_application_data(struct tls13_record_layer *rl);
218 ssize_t tls13_peek_application_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
219 ssize_t tls13_read_application_data(struct tls13_record_layer *rl, uint8_t *buf, size_t n);
220 ssize_t tls13_write_application_data(struct tls13_record_layer *rl, const uint8_t *buf,
221     size_t n);
222 
223 ssize_t tls13_send_alert(struct tls13_record_layer *rl, uint8_t alert_desc);
224 ssize_t tls13_send_dummy_ccs(struct tls13_record_layer *rl);
225 
226 /*
227  * Handshake Messages.
228  */
229 struct tls13_handshake_msg;
230 
231 struct tls13_handshake_msg *tls13_handshake_msg_new(void);
232 void tls13_handshake_msg_free(struct tls13_handshake_msg *msg);
233 void tls13_handshake_msg_data(struct tls13_handshake_msg *msg, CBS *cbs);
234 int tls13_handshake_msg_set_buffer(struct tls13_handshake_msg *msg, CBS *cbs);
235 uint8_t tls13_handshake_msg_type(struct tls13_handshake_msg *msg);
236 int tls13_handshake_msg_content(struct tls13_handshake_msg *msg, CBS *cbs);
237 int tls13_handshake_msg_start(struct tls13_handshake_msg *msg, CBB *body,
238     uint8_t msg_type);
239 int tls13_handshake_msg_finish(struct tls13_handshake_msg *msg);
240 int tls13_handshake_msg_recv(struct tls13_handshake_msg *msg,
241     struct tls13_record_layer *rl);
242 int tls13_handshake_msg_send(struct tls13_handshake_msg *msg,
243     struct tls13_record_layer *rl);
244 
245 struct tls13_handshake_stage {
246 	uint8_t	hs_type;
247 	uint8_t	message_number;
248 };
249 
250 struct ssl_handshake_tls13_st;
251 
252 struct tls13_error {
253 	int code;
254 	int subcode;
255 	int errnum;
256 	const char *file;
257 	int line;
258 	char *msg;
259 };
260 
261 struct tls13_ctx {
262 	struct tls13_error error;
263 
264 	SSL *ssl;
265 	struct ssl_handshake_tls13_st *hs;
266 	uint8_t	mode;
267 	struct tls13_handshake_stage handshake_stage;
268 	int handshake_started;
269 	int handshake_completed;
270 	int middlebox_compat;
271 	int send_dummy_ccs;
272 	int send_dummy_ccs_after;
273 
274 	int close_notify_sent;
275 	int close_notify_recv;
276 
277 	const EVP_AEAD *aead;
278 	const EVP_MD *hash;
279 
280 	struct tls13_record_layer *rl;
281 	struct tls13_handshake_msg *hs_msg;
282 	uint8_t key_update_request;
283 	uint8_t alert;
284 	int phh_count;
285 	time_t phh_last_seen;
286 
287 	tls13_handshake_message_cb handshake_message_sent_cb;
288 	tls13_handshake_message_cb handshake_message_recv_cb;
289 	tls13_info_cb info_cb;
290 	tls13_ocsp_status_cb ocsp_status_recv_cb;
291 };
292 #ifndef TLS13_PHH_LIMIT_TIME
293 #define TLS13_PHH_LIMIT_TIME 3600
294 #endif
295 #ifndef TLS13_PHH_LIMIT
296 #define TLS13_PHH_LIMIT 100
297 #endif
298 
299 struct tls13_ctx *tls13_ctx_new(int mode);
300 void tls13_ctx_free(struct tls13_ctx *ctx);
301 
302 const EVP_AEAD *tls13_cipher_aead(const SSL_CIPHER *cipher);
303 const EVP_MD *tls13_cipher_hash(const SSL_CIPHER *cipher);
304 
305 /*
306  * Legacy interfaces.
307  */
308 int tls13_use_legacy_client(struct tls13_ctx *ctx);
309 int tls13_use_legacy_server(struct tls13_ctx *ctx);
310 int tls13_legacy_accept(SSL *ssl);
311 int tls13_legacy_connect(SSL *ssl);
312 int tls13_legacy_return_code(SSL *ssl, ssize_t ret);
313 ssize_t tls13_legacy_wire_read_cb(void *buf, size_t n, void *arg);
314 ssize_t tls13_legacy_wire_write_cb(const void *buf, size_t n, void *arg);
315 int tls13_legacy_pending(const SSL *ssl);
316 int tls13_legacy_read_bytes(SSL *ssl, int type, unsigned char *buf, int len,
317     int peek);
318 int tls13_legacy_write_bytes(SSL *ssl, int type, const void *buf, int len);
319 int tls13_legacy_shutdown(SSL *ssl);
320 int tls13_legacy_servername_process(struct tls13_ctx *ctx, uint8_t *alert);
321 
322 /*
323  * Message Types - RFC 8446, Section B.3.
324  *
325  * Values listed as "_RESERVED" were used in previous versions of TLS and are
326  * listed here for completeness.  TLS 1.3 implementations MUST NOT send them but
327  * might receive them from older TLS implementations.
328  */
329 #define	TLS13_MT_HELLO_REQUEST_RESERVED		0
330 #define	TLS13_MT_CLIENT_HELLO			1
331 #define	TLS13_MT_SERVER_HELLO			2
332 #define	TLS13_MT_HELLO_VERIFY_REQUEST_RESERVED	3
333 #define	TLS13_MT_NEW_SESSION_TICKET		4
334 #define	TLS13_MT_END_OF_EARLY_DATA		5
335 #define	TLS13_MT_HELLO_RETRY_REQUEST_RESERVED	6
336 #define	TLS13_MT_ENCRYPTED_EXTENSIONS		8
337 #define	TLS13_MT_CERTIFICATE			11
338 #define	TLS13_MT_SERVER_KEY_EXCHANGE_RESERVED	12
339 #define	TLS13_MT_CERTIFICATE_REQUEST		13
340 #define	TLS13_MT_SERVER_HELLO_DONE_RESERVED	14
341 #define	TLS13_MT_CERTIFICATE_VERIFY		15
342 #define	TLS13_MT_CLIENT_KEY_EXCHANGE_RESERVED	16
343 #define	TLS13_MT_FINISHED			20
344 #define	TLS13_MT_CERTIFICATE_URL_RESERVED	21
345 #define	TLS13_MT_CERTIFICATE_STATUS_RESERVED	22
346 #define	TLS13_MT_SUPPLEMENTAL_DATA_RESERVED	23
347 #define	TLS13_MT_KEY_UPDATE			24
348 #define	TLS13_MT_MESSAGE_HASH			254
349 
350 int tls13_handshake_msg_record(struct tls13_ctx *ctx);
351 int tls13_handshake_perform(struct tls13_ctx *ctx);
352 
353 int tls13_client_init(struct tls13_ctx *ctx);
354 int tls13_server_init(struct tls13_ctx *ctx);
355 int tls13_client_connect(struct tls13_ctx *ctx);
356 int tls13_server_accept(struct tls13_ctx *ctx);
357 
358 int tls13_client_hello_send(struct tls13_ctx *ctx, CBB *cbb);
359 int tls13_client_hello_sent(struct tls13_ctx *ctx);
360 int tls13_client_hello_recv(struct tls13_ctx *ctx, CBS *cbs);
361 int tls13_client_hello_retry_send(struct tls13_ctx *ctx, CBB *cbb);
362 int tls13_client_hello_retry_recv(struct tls13_ctx *ctx, CBS *cbs);
363 int tls13_client_end_of_early_data_send(struct tls13_ctx *ctx, CBB *cbb);
364 int tls13_client_end_of_early_data_recv(struct tls13_ctx *ctx, CBS *cbs);
365 int tls13_client_certificate_send(struct tls13_ctx *ctx, CBB *cbb);
366 int tls13_client_certificate_recv(struct tls13_ctx *ctx, CBS *cbs);
367 int tls13_client_certificate_verify_send(struct tls13_ctx *ctx, CBB *cbb);
368 int tls13_client_certificate_verify_recv(struct tls13_ctx *ctx, CBS *cbs);
369 int tls13_client_finished_recv(struct tls13_ctx *ctx, CBS *cbs);
370 int tls13_client_finished_send(struct tls13_ctx *ctx, CBB *cbb);
371 int tls13_client_finished_sent(struct tls13_ctx *ctx);
372 int tls13_server_hello_recv(struct tls13_ctx *ctx, CBS *cbs);
373 int tls13_server_hello_send(struct tls13_ctx *ctx, CBB *cbb);
374 int tls13_server_hello_sent(struct tls13_ctx *ctx);
375 int tls13_server_hello_retry_request_recv(struct tls13_ctx *ctx, CBS *cbs);
376 int tls13_server_hello_retry_request_send(struct tls13_ctx *ctx, CBB *cbb);
377 int tls13_server_hello_retry_request_sent(struct tls13_ctx *ctx);
378 int tls13_server_encrypted_extensions_recv(struct tls13_ctx *ctx, CBS *cbs);
379 int tls13_server_encrypted_extensions_send(struct tls13_ctx *ctx, CBB *cbb);
380 int tls13_server_certificate_recv(struct tls13_ctx *ctx, CBS *cbs);
381 int tls13_server_certificate_send(struct tls13_ctx *ctx, CBB *cbb);
382 int tls13_server_certificate_request_recv(struct tls13_ctx *ctx, CBS *cbs);
383 int tls13_server_certificate_request_send(struct tls13_ctx *ctx, CBB *cbb);
384 int tls13_server_certificate_verify_send(struct tls13_ctx *ctx, CBB *cbb);
385 int tls13_server_certificate_verify_recv(struct tls13_ctx *ctx, CBS *cbs);
386 int tls13_server_finished_recv(struct tls13_ctx *ctx, CBS *cbs);
387 int tls13_server_finished_send(struct tls13_ctx *ctx, CBB *cbb);
388 int tls13_server_finished_sent(struct tls13_ctx *ctx);
389 
390 void tls13_error_clear(struct tls13_error *error);
391 int tls13_cert_add(struct tls13_ctx *ctx, CBB *cbb, X509 *cert,
392     int(*build_extensions)(SSL *s, uint16_t msg_type, CBB *cbb));
393 
394 int tls13_synthetic_handshake_message(struct tls13_ctx *ctx);
395 int tls13_clienthello_hash_init(struct tls13_ctx *ctx);
396 void tls13_clienthello_hash_clear(struct ssl_handshake_tls13_st *hs);
397 int tls13_clienthello_hash_update_bytes(struct tls13_ctx *ctx, void *data,
398     size_t len);
399 int tls13_clienthello_hash_update(struct tls13_ctx *ctx, CBS *cbs);
400 int tls13_clienthello_hash_finalize(struct tls13_ctx *ctx);
401 int tls13_clienthello_hash_validate(struct tls13_ctx *ctx);
402 
403 int tls13_error_set(struct tls13_error *error, int code, int subcode,
404     const char *file, int line, const char *fmt, ...);
405 int tls13_error_setx(struct tls13_error *error, int code, int subcode,
406     const char *file, int line, const char *fmt, ...);
407 
408 #define tls13_set_error(ctx, code, subcode, fmt, ...) \
409 	tls13_error_set(&(ctx)->error, (code), (subcode), __FILE__, __LINE__, \
410 	    (fmt), __VA_ARGS__)
411 #define tls13_set_errorx(ctx, code, subcode, fmt, ...) \
412 	tls13_error_setx(&(ctx)->error, (code), (subcode), __FILE__, __LINE__, \
413 	    (fmt), __VA_ARGS__)
414 
415 extern const uint8_t tls13_downgrade_12[8];
416 extern const uint8_t tls13_downgrade_11[8];
417 extern const uint8_t tls13_hello_retry_request_hash[32];
418 extern const uint8_t tls13_cert_verify_pad[64];
419 extern const uint8_t tls13_cert_client_verify_context[];
420 extern const uint8_t tls13_cert_server_verify_context[];
421 
422 __END_HIDDEN_DECLS
423 
424 #endif
425