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authorcvs2svn <admin@example.com>2022-05-04 18:02:08 +0000
committercvs2svn <admin@example.com>2022-05-04 18:02:08 +0000
commit3c94dc45dfb15483d76c47a128ec352cc0b655ac (patch)
treea7cfb4512c784e9518f1b1c2f4009295b8766ef4 /src/lib/libssl/tls13_lib.c
parentf32cca700e59c0fd1ddd8f1fd4b35a5401be28fe (diff)
downloadopenbsd-tb_20220504.tar.gz
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This commit was manufactured by cvs2git to create tag 'tb_20220504'.tb_20220504
Diffstat (limited to '')
-rw-r--r--src/lib/libssl/tls13_lib.c644
1 files changed, 0 insertions, 644 deletions
diff --git a/src/lib/libssl/tls13_lib.c b/src/lib/libssl/tls13_lib.c
deleted file mode 100644
index 20d3a38412..0000000000
--- a/src/lib/libssl/tls13_lib.c
+++ /dev/null
@@ -1,644 +0,0 @@
1/* $OpenBSD: tls13_lib.c,v 1.63 2022/02/05 14:54:10 jsing Exp $ */
2/*
3 * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
4 * Copyright (c) 2019 Bob Beck <beck@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <stddef.h>
20
21#include <openssl/evp.h>
22
23#include "ssl_locl.h"
24#include "ssl_tlsext.h"
25#include "tls13_internal.h"
26
27/*
28 * Downgrade sentinels - RFC 8446 section 4.1.3, magic values which must be set
29 * by the server in server random if it is willing to downgrade but supports
30 * TLSv1.3
31 */
32const uint8_t tls13_downgrade_12[8] = {
33 0x44, 0x4f, 0x57, 0x4e, 0x47, 0x52, 0x44, 0x01,
34};
35const uint8_t tls13_downgrade_11[8] = {
36 0x44, 0x4f, 0x57, 0x4e, 0x47, 0x52, 0x44, 0x00,
37};
38
39/*
40 * HelloRetryRequest hash - RFC 8446 section 4.1.3.
41 */
42const uint8_t tls13_hello_retry_request_hash[32] = {
43 0xcf, 0x21, 0xad, 0x74, 0xe5, 0x9a, 0x61, 0x11,
44 0xbe, 0x1d, 0x8c, 0x02, 0x1e, 0x65, 0xb8, 0x91,
45 0xc2, 0xa2, 0x11, 0x16, 0x7a, 0xbb, 0x8c, 0x5e,
46 0x07, 0x9e, 0x09, 0xe2, 0xc8, 0xa8, 0x33, 0x9c,
47};
48
49/*
50 * Certificate Verify padding - RFC 8446 section 4.4.3.
51 */
52const uint8_t tls13_cert_verify_pad[64] = {
53 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
54 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
55 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
56 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
57 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
58 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
59 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
60 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
61};
62
63const uint8_t tls13_cert_client_verify_context[] =
64 "TLS 1.3, client CertificateVerify";
65const uint8_t tls13_cert_server_verify_context[] =
66 "TLS 1.3, server CertificateVerify";
67
68const EVP_AEAD *
69tls13_cipher_aead(const SSL_CIPHER *cipher)
70{
71 if (cipher == NULL)
72 return NULL;
73 if (cipher->algorithm_ssl != SSL_TLSV1_3)
74 return NULL;
75
76 switch (cipher->algorithm_enc) {
77 case SSL_AES128GCM:
78 return EVP_aead_aes_128_gcm();
79 case SSL_AES256GCM:
80 return EVP_aead_aes_256_gcm();
81 case SSL_CHACHA20POLY1305:
82 return EVP_aead_chacha20_poly1305();
83 }
84
85 return NULL;
86}
87
88const EVP_MD *
89tls13_cipher_hash(const SSL_CIPHER *cipher)
90{
91 if (cipher == NULL)
92 return NULL;
93 if (cipher->algorithm_ssl != SSL_TLSV1_3)
94 return NULL;
95
96 switch (cipher->algorithm2) {
97 case SSL_HANDSHAKE_MAC_SHA256:
98 return EVP_sha256();
99 case SSL_HANDSHAKE_MAC_SHA384:
100 return EVP_sha384();
101 }
102
103 return NULL;
104}
105
106static void
107tls13_alert_received_cb(uint8_t alert_desc, void *arg)
108{
109 struct tls13_ctx *ctx = arg;
110
111 if (alert_desc == TLS13_ALERT_CLOSE_NOTIFY) {
112 ctx->close_notify_recv = 1;
113 ctx->ssl->internal->shutdown |= SSL_RECEIVED_SHUTDOWN;
114 ctx->ssl->s3->warn_alert = alert_desc;
115 return;
116 }
117
118 if (alert_desc == TLS13_ALERT_USER_CANCELED) {
119 /*
120 * We treat this as advisory, since a close_notify alert
121 * SHOULD follow this alert (RFC 8446 section 6.1).
122 */
123 return;
124 }
125
126 /* All other alerts are treated as fatal in TLSv1.3. */
127 ctx->ssl->s3->fatal_alert = alert_desc;
128
129 SSLerror(ctx->ssl, SSL_AD_REASON_OFFSET + alert_desc);
130 ERR_asprintf_error_data("SSL alert number %d", alert_desc);
131
132 SSL_CTX_remove_session(ctx->ssl->ctx, ctx->ssl->session);
133}
134
135static void
136tls13_alert_sent_cb(uint8_t alert_desc, void *arg)
137{
138 struct tls13_ctx *ctx = arg;
139
140 if (alert_desc == TLS13_ALERT_CLOSE_NOTIFY) {
141 ctx->close_notify_sent = 1;
142 return;
143 }
144
145 if (alert_desc == TLS13_ALERT_USER_CANCELED) {
146 return;
147 }
148
149 /* All other alerts are treated as fatal in TLSv1.3. */
150 if (ctx->error.code == 0)
151 SSLerror(ctx->ssl, SSL_AD_REASON_OFFSET + alert_desc);
152}
153
154static void
155tls13_legacy_handshake_message_recv_cb(void *arg)
156{
157 struct tls13_ctx *ctx = arg;
158 SSL *s = ctx->ssl;
159 CBS cbs;
160
161 if (s->internal->msg_callback == NULL)
162 return;
163
164 tls13_handshake_msg_data(ctx->hs_msg, &cbs);
165 ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE, CBS_data(&cbs), CBS_len(&cbs));
166}
167
168static void
169tls13_legacy_handshake_message_sent_cb(void *arg)
170{
171 struct tls13_ctx *ctx = arg;
172 SSL *s = ctx->ssl;
173 CBS cbs;
174
175 if (s->internal->msg_callback == NULL)
176 return;
177
178 tls13_handshake_msg_data(ctx->hs_msg, &cbs);
179 ssl_msg_callback(s, 1, SSL3_RT_HANDSHAKE, CBS_data(&cbs), CBS_len(&cbs));
180}
181
182static void
183tls13_legacy_info_cb(void *arg, int state, int ret)
184{
185 struct tls13_ctx *ctx = arg;
186 SSL *s = ctx->ssl;
187
188 ssl_info_callback(s, state, ret);
189}
190
191static int
192tls13_legacy_ocsp_status_recv_cb(void *arg)
193{
194 struct tls13_ctx *ctx = arg;
195 SSL *s = ctx->ssl;
196 int ret;
197
198 if (s->ctx->internal->tlsext_status_cb == NULL)
199 return 1;
200
201 ret = s->ctx->internal->tlsext_status_cb(s,
202 s->ctx->internal->tlsext_status_arg);
203 if (ret < 0) {
204 ctx->alert = TLS13_ALERT_INTERNAL_ERROR;
205 SSLerror(s, ERR_R_MALLOC_FAILURE);
206 return 0;
207 }
208 if (ret == 0) {
209 ctx->alert = TLS13_ALERT_BAD_CERTIFICATE_STATUS_RESPONSE;
210 SSLerror(s, SSL_R_INVALID_STATUS_RESPONSE);
211 return 0;
212 }
213
214 return 1;
215}
216
217static int
218tls13_phh_update_local_traffic_secret(struct tls13_ctx *ctx)
219{
220 struct tls13_secrets *secrets = ctx->hs->tls13.secrets;
221
222 if (ctx->mode == TLS13_HS_CLIENT)
223 return (tls13_update_client_traffic_secret(secrets) &&
224 tls13_record_layer_set_write_traffic_key(ctx->rl,
225 &secrets->client_application_traffic));
226 return (tls13_update_server_traffic_secret(secrets) &&
227 tls13_record_layer_set_read_traffic_key(ctx->rl,
228 &secrets->server_application_traffic));
229}
230
231static int
232tls13_phh_update_peer_traffic_secret(struct tls13_ctx *ctx)
233{
234 struct tls13_secrets *secrets = ctx->hs->tls13.secrets;
235
236 if (ctx->mode == TLS13_HS_CLIENT)
237 return (tls13_update_server_traffic_secret(secrets) &&
238 tls13_record_layer_set_read_traffic_key(ctx->rl,
239 &secrets->server_application_traffic));
240 return (tls13_update_client_traffic_secret(secrets) &&
241 tls13_record_layer_set_write_traffic_key(ctx->rl,
242 &secrets->client_application_traffic));
243}
244
245/*
246 * XXX arbitrarily chosen limit of 100 post handshake handshake
247 * messages in an hour - to avoid a hostile peer from constantly
248 * requesting certificates or key renegotiaitons, etc.
249 */
250static int
251tls13_phh_limit_check(struct tls13_ctx *ctx)
252{
253 time_t now = time(NULL);
254
255 if (ctx->phh_last_seen > now - TLS13_PHH_LIMIT_TIME) {
256 if (ctx->phh_count > TLS13_PHH_LIMIT)
257 return 0;
258 } else
259 ctx->phh_count = 0;
260 ctx->phh_count++;
261 ctx->phh_last_seen = now;
262 return 1;
263}
264
265static ssize_t
266tls13_key_update_recv(struct tls13_ctx *ctx, CBS *cbs)
267{
268 struct tls13_handshake_msg *hs_msg = NULL;
269 CBB cbb_hs;
270 CBS cbs_hs;
271 uint8_t alert = TLS13_ALERT_INTERNAL_ERROR;
272 uint8_t key_update_request;
273 ssize_t ret;
274
275 if (!CBS_get_u8(cbs, &key_update_request)) {
276 alert = TLS13_ALERT_DECODE_ERROR;
277 goto err;
278 }
279 if (CBS_len(cbs) != 0) {
280 alert = TLS13_ALERT_DECODE_ERROR;
281 goto err;
282 }
283 if (key_update_request > 1) {
284 alert = TLS13_ALERT_ILLEGAL_PARAMETER;
285 goto err;
286 }
287
288 if (!tls13_phh_update_peer_traffic_secret(ctx))
289 goto err;
290
291 if (key_update_request == 0)
292 return TLS13_IO_SUCCESS;
293
294 /* key_update_request == 1 */
295 if ((hs_msg = tls13_handshake_msg_new()) == NULL)
296 goto err;
297 if (!tls13_handshake_msg_start(hs_msg, &cbb_hs, TLS13_MT_KEY_UPDATE))
298 goto err;
299 if (!CBB_add_u8(&cbb_hs, 0))
300 goto err;
301 if (!tls13_handshake_msg_finish(hs_msg))
302 goto err;
303
304 ctx->key_update_request = 1;
305 tls13_handshake_msg_data(hs_msg, &cbs_hs);
306 ret = tls13_record_layer_phh(ctx->rl, &cbs_hs);
307
308 tls13_handshake_msg_free(hs_msg);
309 hs_msg = NULL;
310
311 return ret;
312
313 err:
314 tls13_handshake_msg_free(hs_msg);
315
316 return tls13_send_alert(ctx->rl, alert);
317}
318
319static void
320tls13_phh_done_cb(void *cb_arg)
321{
322 struct tls13_ctx *ctx = cb_arg;
323
324 if (ctx->key_update_request) {
325 tls13_phh_update_local_traffic_secret(ctx);
326 ctx->key_update_request = 0;
327 }
328}
329
330static ssize_t
331tls13_phh_received_cb(void *cb_arg, CBS *cbs)
332{
333 ssize_t ret = TLS13_IO_FAILURE;
334 struct tls13_ctx *ctx = cb_arg;
335 CBS phh_cbs;
336
337 if (!tls13_phh_limit_check(ctx))
338 return tls13_send_alert(ctx->rl, TLS13_ALERT_UNEXPECTED_MESSAGE);
339
340 if ((ctx->hs_msg == NULL) &&
341 ((ctx->hs_msg = tls13_handshake_msg_new()) == NULL))
342 return TLS13_IO_FAILURE;
343
344 if (!tls13_handshake_msg_set_buffer(ctx->hs_msg, cbs))
345 return TLS13_IO_FAILURE;
346
347 if ((ret = tls13_handshake_msg_recv(ctx->hs_msg, ctx->rl))
348 != TLS13_IO_SUCCESS)
349 return ret;
350
351 if (!tls13_handshake_msg_content(ctx->hs_msg, &phh_cbs))
352 return TLS13_IO_FAILURE;
353
354 switch(tls13_handshake_msg_type(ctx->hs_msg)) {
355 case TLS13_MT_KEY_UPDATE:
356 ret = tls13_key_update_recv(ctx, &phh_cbs);
357 break;
358 case TLS13_MT_NEW_SESSION_TICKET:
359 /* XXX do nothing for now and ignore this */
360 break;
361 case TLS13_MT_CERTIFICATE_REQUEST:
362 /* XXX add support if we choose to advertise this */
363 /* FALLTHROUGH */
364 default:
365 ret = TLS13_IO_FAILURE; /* XXX send alert */
366 break;
367 }
368
369 tls13_handshake_msg_free(ctx->hs_msg);
370 ctx->hs_msg = NULL;
371 return ret;
372}
373
374static const struct tls13_record_layer_callbacks rl_callbacks = {
375 .wire_read = tls13_legacy_wire_read_cb,
376 .wire_write = tls13_legacy_wire_write_cb,
377 .wire_flush = tls13_legacy_wire_flush_cb,
378 .alert_recv = tls13_alert_received_cb,
379 .alert_sent = tls13_alert_sent_cb,
380 .phh_recv = tls13_phh_received_cb,
381 .phh_sent = tls13_phh_done_cb,
382};
383
384struct tls13_ctx *
385tls13_ctx_new(int mode)
386{
387 struct tls13_ctx *ctx = NULL;
388
389 if ((ctx = calloc(sizeof(struct tls13_ctx), 1)) == NULL)
390 goto err;
391
392 ctx->mode = mode;
393
394 if ((ctx->rl = tls13_record_layer_new(&rl_callbacks, ctx)) == NULL)
395 goto err;
396
397 ctx->handshake_message_sent_cb = tls13_legacy_handshake_message_sent_cb;
398 ctx->handshake_message_recv_cb = tls13_legacy_handshake_message_recv_cb;
399 ctx->info_cb = tls13_legacy_info_cb;
400 ctx->ocsp_status_recv_cb = tls13_legacy_ocsp_status_recv_cb;
401
402 ctx->middlebox_compat = 1;
403
404 return ctx;
405
406 err:
407 tls13_ctx_free(ctx);
408
409 return NULL;
410}
411
412void
413tls13_ctx_free(struct tls13_ctx *ctx)
414{
415 if (ctx == NULL)
416 return;
417
418 tls13_error_clear(&ctx->error);
419 tls13_record_layer_free(ctx->rl);
420 tls13_handshake_msg_free(ctx->hs_msg);
421
422 freezero(ctx, sizeof(struct tls13_ctx));
423}
424
425int
426tls13_cert_add(struct tls13_ctx *ctx, CBB *cbb, X509 *cert,
427 int (*build_extensions)(SSL *s, uint16_t msg_type, CBB *cbb))
428{
429 CBB cert_data, cert_exts;
430 uint8_t *data;
431 int cert_len;
432
433 if ((cert_len = i2d_X509(cert, NULL)) < 0)
434 return 0;
435
436 if (!CBB_add_u24_length_prefixed(cbb, &cert_data))
437 return 0;
438 if (!CBB_add_space(&cert_data, &data, cert_len))
439 return 0;
440 if (i2d_X509(cert, &data) != cert_len)
441 return 0;
442 if (build_extensions != NULL) {
443 if (!build_extensions(ctx->ssl, SSL_TLSEXT_MSG_CT, cbb))
444 return 0;
445 } else {
446 if (!CBB_add_u16_length_prefixed(cbb, &cert_exts))
447 return 0;
448 }
449 if (!CBB_flush(cbb))
450 return 0;
451
452 return 1;
453}
454
455int
456tls13_synthetic_handshake_message(struct tls13_ctx *ctx)
457{
458 struct tls13_handshake_msg *hm = NULL;
459 unsigned char buf[EVP_MAX_MD_SIZE];
460 size_t hash_len;
461 CBB cbb;
462 CBS cbs;
463 SSL *s = ctx->ssl;
464 int ret = 0;
465
466 /*
467 * Replace ClientHello with synthetic handshake message - see
468 * RFC 8446 section 4.4.1.
469 */
470 if (!tls1_transcript_hash_init(s))
471 goto err;
472 if (!tls1_transcript_hash_value(s, buf, sizeof(buf), &hash_len))
473 goto err;
474
475 if ((hm = tls13_handshake_msg_new()) == NULL)
476 goto err;
477 if (!tls13_handshake_msg_start(hm, &cbb, TLS13_MT_MESSAGE_HASH))
478 goto err;
479 if (!CBB_add_bytes(&cbb, buf, hash_len))
480 goto err;
481 if (!tls13_handshake_msg_finish(hm))
482 goto err;
483
484 tls13_handshake_msg_data(hm, &cbs);
485
486 tls1_transcript_reset(ctx->ssl);
487 if (!tls1_transcript_record(ctx->ssl, CBS_data(&cbs), CBS_len(&cbs)))
488 goto err;
489
490 ret = 1;
491
492 err:
493 tls13_handshake_msg_free(hm);
494
495 return ret;
496}
497
498int
499tls13_clienthello_hash_init(struct tls13_ctx *ctx)
500{
501 if (ctx->hs->tls13.clienthello_md_ctx != NULL)
502 return 0;
503 if ((ctx->hs->tls13.clienthello_md_ctx = EVP_MD_CTX_new()) == NULL)
504 return 0;
505 if (!EVP_DigestInit_ex(ctx->hs->tls13.clienthello_md_ctx,
506 EVP_sha256(), NULL))
507 return 0;
508
509 if ((ctx->hs->tls13.clienthello_hash == NULL) &&
510 (ctx->hs->tls13.clienthello_hash = calloc(1, EVP_MAX_MD_SIZE)) ==
511 NULL)
512 return 0;
513
514 return 1;
515}
516
517void
518tls13_clienthello_hash_clear(struct ssl_handshake_tls13_st *hs) /* XXX */
519{
520 EVP_MD_CTX_free(hs->clienthello_md_ctx);
521 hs->clienthello_md_ctx = NULL;
522 freezero(hs->clienthello_hash, EVP_MAX_MD_SIZE);
523 hs->clienthello_hash = NULL;
524}
525
526int
527tls13_clienthello_hash_update_bytes(struct tls13_ctx *ctx, void *data,
528 size_t len)
529{
530 return EVP_DigestUpdate(ctx->hs->tls13.clienthello_md_ctx, data, len);
531}
532
533int
534tls13_clienthello_hash_update(struct tls13_ctx *ctx, CBS *cbs)
535{
536 return tls13_clienthello_hash_update_bytes(ctx, (void *)CBS_data(cbs),
537 CBS_len(cbs));
538}
539
540int
541tls13_clienthello_hash_finalize(struct tls13_ctx *ctx)
542{
543 if (!EVP_DigestFinal_ex(ctx->hs->tls13.clienthello_md_ctx,
544 ctx->hs->tls13.clienthello_hash,
545 &ctx->hs->tls13.clienthello_hash_len))
546 return 0;
547 EVP_MD_CTX_free(ctx->hs->tls13.clienthello_md_ctx);
548 ctx->hs->tls13.clienthello_md_ctx = NULL;
549 return 1;
550}
551
552int
553tls13_clienthello_hash_validate(struct tls13_ctx *ctx)
554{
555 unsigned char new_ch_hash[EVP_MAX_MD_SIZE];
556 unsigned int new_ch_hash_len;
557
558 if (ctx->hs->tls13.clienthello_hash == NULL)
559 return 0;
560
561 if (!EVP_DigestFinal_ex(ctx->hs->tls13.clienthello_md_ctx,
562 new_ch_hash, &new_ch_hash_len))
563 return 0;
564 EVP_MD_CTX_free(ctx->hs->tls13.clienthello_md_ctx);
565 ctx->hs->tls13.clienthello_md_ctx = NULL;
566
567 if (ctx->hs->tls13.clienthello_hash_len != new_ch_hash_len)
568 return 0;
569 if (memcmp(ctx->hs->tls13.clienthello_hash, new_ch_hash,
570 new_ch_hash_len) != 0)
571 return 0;
572
573 return 1;
574}
575
576int
577tls13_exporter(struct tls13_ctx *ctx, const uint8_t *label, size_t label_len,
578 const uint8_t *context_value, size_t context_value_len, uint8_t *out,
579 size_t out_len)
580{
581 struct tls13_secret context, export_out, export_secret;
582 struct tls13_secrets *secrets = ctx->hs->tls13.secrets;
583 EVP_MD_CTX *md_ctx = NULL;
584 unsigned int md_out_len;
585 int md_len;
586 int ret = 0;
587
588 /*
589 * RFC 8446 Section 7.5.
590 */
591
592 memset(&context, 0, sizeof(context));
593 memset(&export_secret, 0, sizeof(export_secret));
594
595 export_out.data = out;
596 export_out.len = out_len;
597
598 if (!ctx->handshake_completed)
599 return 0;
600
601 md_len = EVP_MD_size(secrets->digest);
602 if (md_len <= 0 || md_len > EVP_MAX_MD_SIZE)
603 goto err;
604
605 if (!tls13_secret_init(&export_secret, md_len))
606 goto err;
607 if (!tls13_secret_init(&context, md_len))
608 goto err;
609
610 /* In TLSv1.3 no context is equivalent to an empty context. */
611 if (context_value == NULL) {
612 context_value = "";
613 context_value_len = 0;
614 }
615
616 if ((md_ctx = EVP_MD_CTX_new()) == NULL)
617 goto err;
618 if (!EVP_DigestInit_ex(md_ctx, secrets->digest, NULL))
619 goto err;
620 if (!EVP_DigestUpdate(md_ctx, context_value, context_value_len))
621 goto err;
622 if (!EVP_DigestFinal_ex(md_ctx, context.data, &md_out_len))
623 goto err;
624 if (md_len != md_out_len)
625 goto err;
626
627 if (!tls13_derive_secret_with_label_length(&export_secret,
628 secrets->digest, &secrets->exporter_master, label, label_len,
629 &secrets->empty_hash))
630 goto err;
631
632 if (!tls13_hkdf_expand_label(&export_out, secrets->digest,
633 &export_secret, "exporter", &context))
634 goto err;
635
636 ret = 1;
637
638 err:
639 EVP_MD_CTX_free(md_ctx);
640 tls13_secret_cleanup(&context);
641 tls13_secret_cleanup(&export_secret);
642
643 return ret;
644}