2 * Copyright 2015-2020 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include "internal/cryptlib.h"
11 #include <openssl/rand.h>
12 #include "../ssl_local.h"
13 #include "statem_local.h"
17 * This file implements the SSL/TLS/DTLS state machines.
19 * There are two primary state machines:
21 * 1) Message flow state machine
22 * 2) Handshake state machine
24 * The Message flow state machine controls the reading and sending of messages
25 * including handling of non-blocking IO events, flushing of the underlying
26 * write BIO, handling unexpected messages, etc. It is itself broken into two
27 * separate sub-state machines which control reading and writing respectively.
29 * The Handshake state machine keeps track of the current SSL/TLS handshake
30 * state. Transitions of the handshake state are the result of events that
31 * occur within the Message flow state machine.
33 * Overall it looks like this:
35 * --------------------------------------------- -------------------
37 * | Message flow state machine | | |
39 * | -------------------- -------------------- | Transition | Handshake state |
40 * | | MSG_FLOW_READING | | MSG_FLOW_WRITING | | Event | machine |
41 * | | sub-state | | sub-state | |----------->| |
42 * | | machine for | | machine for | | | |
43 * | | reading messages | | writing messages | | | |
44 * | -------------------- -------------------- | | |
46 * --------------------------------------------- -------------------
50 /* Sub state machine return values */
52 /* Something bad happened or NBIO */
54 /* Sub state finished go to the next sub state */
56 /* Sub state finished and handshake was completed */
57 SUB_STATE_END_HANDSHAKE
60 static int state_machine(SSL *s, int server);
61 static void init_read_state_machine(SSL *s);
62 static SUB_STATE_RETURN read_state_machine(SSL *s);
63 static void init_write_state_machine(SSL *s);
64 static SUB_STATE_RETURN write_state_machine(SSL *s);
66 OSSL_HANDSHAKE_STATE SSL_get_state(const SSL *ssl)
68 return ssl->statem.hand_state;
71 int SSL_in_init(const SSL *s)
73 return s->statem.in_init;
76 int SSL_is_init_finished(const SSL *s)
78 return !(s->statem.in_init) && (s->statem.hand_state == TLS_ST_OK);
81 int SSL_in_before(const SSL *s)
84 * Historically being "in before" meant before anything had happened. In the
85 * current code though we remain in the "before" state for a while after we
86 * have started the handshake process (e.g. as a server waiting for the
87 * first message to arrive). There "in before" is taken to mean "in before"
88 * and not started any handshake process yet.
90 return (s->statem.hand_state == TLS_ST_BEFORE)
91 && (s->statem.state == MSG_FLOW_UNINITED);
95 * Clear the state machine state and reset back to MSG_FLOW_UNINITED
97 void ossl_statem_clear(SSL *s)
99 s->statem.state = MSG_FLOW_UNINITED;
100 s->statem.hand_state = TLS_ST_BEFORE;
101 s->statem.in_init = 1;
102 s->statem.no_cert_verify = 0;
106 * Set the state machine up ready for a renegotiation handshake
108 void ossl_statem_set_renegotiate(SSL *s)
110 s->statem.in_init = 1;
111 s->statem.request_state = TLS_ST_SW_HELLO_REQ;
114 void ossl_statem_send_fatal(SSL *s, int al)
116 /* We shouldn't call SSLfatal() twice. Once is enough */
117 if (s->statem.in_init && s->statem.state == MSG_FLOW_ERROR)
119 s->statem.in_init = 1;
120 s->statem.state = MSG_FLOW_ERROR;
121 if (al != SSL_AD_NO_ALERT
122 && s->statem.enc_write_state != ENC_WRITE_STATE_INVALID)
123 ssl3_send_alert(s, SSL3_AL_FATAL, al);
127 * Error reporting building block that's used instead of ERR_set_error().
128 * In addition to what ERR_set_error() does, this puts the state machine
129 * into an error state and sends an alert if appropriate.
130 * This is a permanent error for the current connection.
132 void ossl_statem_fatal(SSL *s, int al, int reason, const char *fmt, ...)
137 ERR_vset_error(ERR_LIB_SSL, reason, fmt, args);
140 ossl_statem_send_fatal(s, al);
144 * This macro should only be called if we are already expecting to be in
145 * a fatal error state. We verify that we are, and set it if not (this would
148 #define check_fatal(s) \
150 if (!ossl_assert((s)->statem.in_init \
151 && (s)->statem.state == MSG_FLOW_ERROR)) \
152 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_MISSING_FATAL); \
156 * Discover whether the current connection is in the error state.
158 * Valid return values are:
162 int ossl_statem_in_error(const SSL *s)
164 if (s->statem.state == MSG_FLOW_ERROR)
170 void ossl_statem_set_in_init(SSL *s, int init)
172 s->statem.in_init = init;
175 int ossl_statem_get_in_handshake(SSL *s)
177 return s->statem.in_handshake;
180 void ossl_statem_set_in_handshake(SSL *s, int inhand)
183 s->statem.in_handshake++;
185 s->statem.in_handshake--;
188 /* Are we in a sensible state to skip over unreadable early data? */
189 int ossl_statem_skip_early_data(SSL *s)
191 if (s->ext.early_data != SSL_EARLY_DATA_REJECTED)
195 || s->statem.hand_state != TLS_ST_EARLY_DATA
196 || s->hello_retry_request == SSL_HRR_COMPLETE)
203 * Called when we are in SSL_read*(), SSL_write*(), or SSL_accept()
204 * /SSL_connect()/SSL_do_handshake(). Used to test whether we are in an early
205 * data state and whether we should attempt to move the handshake on if so.
206 * |sending| is 1 if we are attempting to send data (SSL_write*()), 0 if we are
207 * attempting to read data (SSL_read*()), or -1 if we are in SSL_do_handshake()
210 void ossl_statem_check_finish_init(SSL *s, int sending)
213 if (s->statem.hand_state == TLS_ST_PENDING_EARLY_DATA_END
214 || s->statem.hand_state == TLS_ST_EARLY_DATA) {
215 ossl_statem_set_in_init(s, 1);
216 if (s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) {
218 * SSL_connect() or SSL_do_handshake() has been called directly.
219 * We don't allow any more writing of early data.
221 s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
224 } else if (!s->server) {
225 if ((sending && (s->statem.hand_state == TLS_ST_PENDING_EARLY_DATA_END
226 || s->statem.hand_state == TLS_ST_EARLY_DATA)
227 && s->early_data_state != SSL_EARLY_DATA_WRITING)
228 || (!sending && s->statem.hand_state == TLS_ST_EARLY_DATA)) {
229 ossl_statem_set_in_init(s, 1);
231 * SSL_write() has been called directly. We don't allow any more
232 * writing of early data.
234 if (sending && s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY)
235 s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
238 if (s->early_data_state == SSL_EARLY_DATA_FINISHED_READING
239 && s->statem.hand_state == TLS_ST_EARLY_DATA)
240 ossl_statem_set_in_init(s, 1);
244 void ossl_statem_set_hello_verify_done(SSL *s)
246 s->statem.state = MSG_FLOW_UNINITED;
247 s->statem.in_init = 1;
249 * This will get reset (briefly) back to TLS_ST_BEFORE when we enter
250 * state_machine() because |state| is MSG_FLOW_UNINITED, but until then any
251 * calls to SSL_in_before() will return false. Also calls to
252 * SSL_state_string() and SSL_state_string_long() will return something
255 s->statem.hand_state = TLS_ST_SR_CLNT_HELLO;
258 int ossl_statem_connect(SSL *s)
260 return state_machine(s, 0);
263 int ossl_statem_accept(SSL *s)
265 return state_machine(s, 1);
268 typedef void (*info_cb) (const SSL *, int, int);
270 static info_cb get_callback(SSL *s)
272 if (s->info_callback != NULL)
273 return s->info_callback;
274 else if (s->ctx->info_callback != NULL)
275 return s->ctx->info_callback;
281 * The main message flow state machine. We start in the MSG_FLOW_UNINITED or
282 * MSG_FLOW_FINISHED state and finish in MSG_FLOW_FINISHED. Valid states and
283 * transitions are as follows:
285 * MSG_FLOW_UNINITED MSG_FLOW_FINISHED
287 * +-----------------------+
289 * MSG_FLOW_WRITING <---> MSG_FLOW_READING
297 * We may exit at any point due to an error or NBIO event. If an NBIO event
298 * occurs then we restart at the point we left off when we are recalled.
299 * MSG_FLOW_WRITING and MSG_FLOW_READING have sub-state machines associated with them.
301 * In addition to the above there is also the MSG_FLOW_ERROR state. We can move
302 * into that state at any point in the event that an irrecoverable error occurs.
304 * Valid return values are:
308 static int state_machine(SSL *s, int server)
311 void (*cb) (const SSL *ssl, int type, int val) = NULL;
312 OSSL_STATEM *st = &s->statem;
316 if (st->state == MSG_FLOW_ERROR) {
317 /* Shouldn't have been called if we're already in the error state */
324 cb = get_callback(s);
327 if (!SSL_in_init(s) || SSL_in_before(s)) {
329 * If we are stateless then we already called SSL_clear() - don't do
330 * it again and clear the STATELESS flag itself.
332 if ((s->s3.flags & TLS1_FLAGS_STATELESS) == 0 && !SSL_clear(s))
335 #ifndef OPENSSL_NO_SCTP
336 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
338 * Notify SCTP BIO socket to enter handshake mode and prevent stream
339 * identifier other than 0.
341 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
342 st->in_handshake, NULL);
346 /* Initialise state machine */
347 if (st->state == MSG_FLOW_UNINITED
348 || st->state == MSG_FLOW_FINISHED) {
349 if (st->state == MSG_FLOW_UNINITED) {
350 st->hand_state = TLS_ST_BEFORE;
351 st->request_state = TLS_ST_BEFORE;
356 if (SSL_IS_FIRST_HANDSHAKE(s) || !SSL_IS_TLS13(s))
357 cb(s, SSL_CB_HANDSHAKE_START, 1);
361 * Fatal errors in this block don't send an alert because we have
362 * failed to even initialise properly. Sending an alert is probably
366 if (SSL_IS_DTLS(s)) {
367 if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
368 (server || (s->version & 0xff00) != (DTLS1_BAD_VER & 0xff00))) {
369 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
373 if ((s->version >> 8) != SSL3_VERSION_MAJOR) {
374 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
379 if (!ssl_security(s, SSL_SECOP_VERSION, 0, s->version, NULL)) {
380 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
384 if (s->init_buf == NULL) {
385 if ((buf = BUF_MEM_new()) == NULL) {
386 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
389 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
390 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
397 if (!ssl3_setup_buffers(s)) {
398 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
404 * Should have been reset by tls_process_finished, too.
406 s->s3.change_cipher_spec = 0;
409 * Ok, we now need to push on a buffering BIO ...but not with
412 #ifndef OPENSSL_NO_SCTP
413 if (!SSL_IS_DTLS(s) || !BIO_dgram_is_sctp(SSL_get_wbio(s)))
415 if (!ssl_init_wbio_buffer(s)) {
416 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
420 if ((SSL_in_before(s))
422 if (!tls_setup_handshake(s)) {
423 /* SSLfatal() already called */
427 if (SSL_IS_FIRST_HANDSHAKE(s))
428 st->read_state_first_init = 1;
431 st->state = MSG_FLOW_WRITING;
432 init_write_state_machine(s);
435 while (st->state != MSG_FLOW_FINISHED) {
436 if (st->state == MSG_FLOW_READING) {
437 ssret = read_state_machine(s);
438 if (ssret == SUB_STATE_FINISHED) {
439 st->state = MSG_FLOW_WRITING;
440 init_write_state_machine(s);
445 } else if (st->state == MSG_FLOW_WRITING) {
446 ssret = write_state_machine(s);
447 if (ssret == SUB_STATE_FINISHED) {
448 st->state = MSG_FLOW_READING;
449 init_read_state_machine(s);
450 } else if (ssret == SUB_STATE_END_HANDSHAKE) {
451 st->state = MSG_FLOW_FINISHED;
459 ERR_raise(ERR_LIB_SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
469 #ifndef OPENSSL_NO_SCTP
470 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
472 * Notify SCTP BIO socket to leave handshake mode and allow stream
473 * identifier other than 0.
475 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
476 st->in_handshake, NULL);
483 cb(s, SSL_CB_ACCEPT_EXIT, ret);
485 cb(s, SSL_CB_CONNECT_EXIT, ret);
491 * Initialise the MSG_FLOW_READING sub-state machine
493 static void init_read_state_machine(SSL *s)
495 OSSL_STATEM *st = &s->statem;
497 st->read_state = READ_STATE_HEADER;
500 static int grow_init_buf(SSL *s, size_t size) {
502 size_t msg_offset = (char *)s->init_msg - s->init_buf->data;
504 if (!BUF_MEM_grow_clean(s->init_buf, (int)size))
507 if (size < msg_offset)
510 s->init_msg = s->init_buf->data + msg_offset;
516 * This function implements the sub-state machine when the message flow is in
517 * MSG_FLOW_READING. The valid sub-states and transitions are:
519 * READ_STATE_HEADER <--+<-------------+
522 * READ_STATE_BODY -----+-->READ_STATE_POST_PROCESS
524 * +----------------------------+
526 * [SUB_STATE_FINISHED]
528 * READ_STATE_HEADER has the responsibility for reading in the message header
529 * and transitioning the state of the handshake state machine.
531 * READ_STATE_BODY reads in the rest of the message and then subsequently
534 * READ_STATE_POST_PROCESS is an optional step that may occur if some post
535 * processing activity performed on the message may block.
537 * Any of the above states could result in an NBIO event occurring in which case
538 * control returns to the calling application. When this function is recalled we
539 * will resume in the same state where we left off.
541 static SUB_STATE_RETURN read_state_machine(SSL *s)
543 OSSL_STATEM *st = &s->statem;
546 int (*transition) (SSL *s, int mt);
548 MSG_PROCESS_RETURN(*process_message) (SSL *s, PACKET *pkt);
549 WORK_STATE(*post_process_message) (SSL *s, WORK_STATE wst);
550 size_t (*max_message_size) (SSL *s);
551 void (*cb) (const SSL *ssl, int type, int val) = NULL;
553 cb = get_callback(s);
556 transition = ossl_statem_server_read_transition;
557 process_message = ossl_statem_server_process_message;
558 max_message_size = ossl_statem_server_max_message_size;
559 post_process_message = ossl_statem_server_post_process_message;
561 transition = ossl_statem_client_read_transition;
562 process_message = ossl_statem_client_process_message;
563 max_message_size = ossl_statem_client_max_message_size;
564 post_process_message = ossl_statem_client_post_process_message;
567 if (st->read_state_first_init) {
569 st->read_state_first_init = 0;
573 switch (st->read_state) {
574 case READ_STATE_HEADER:
575 /* Get the state the peer wants to move to */
576 if (SSL_IS_DTLS(s)) {
578 * In DTLS we get the whole message in one go - header and body
580 ret = dtls_get_message(s, &mt, &len);
582 ret = tls_get_message_header(s, &mt);
586 /* Could be non-blocking IO */
587 return SUB_STATE_ERROR;
591 /* Notify callback of an impending state change */
593 cb(s, SSL_CB_ACCEPT_LOOP, 1);
595 cb(s, SSL_CB_CONNECT_LOOP, 1);
598 * Validate that we are allowed to move to the new state and move
599 * to that state if so
601 if (!transition(s, mt))
602 return SUB_STATE_ERROR;
604 if (s->s3.tmp.message_size > max_message_size(s)) {
605 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
606 SSL_R_EXCESSIVE_MESSAGE_SIZE);
607 return SUB_STATE_ERROR;
610 /* dtls_get_message already did this */
612 && s->s3.tmp.message_size > 0
613 && !grow_init_buf(s, s->s3.tmp.message_size
614 + SSL3_HM_HEADER_LENGTH)) {
615 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_BUF_LIB);
616 return SUB_STATE_ERROR;
619 st->read_state = READ_STATE_BODY;
622 case READ_STATE_BODY:
623 if (!SSL_IS_DTLS(s)) {
624 /* We already got this above for DTLS */
625 ret = tls_get_message_body(s, &len);
627 /* Could be non-blocking IO */
628 return SUB_STATE_ERROR;
633 if (!PACKET_buf_init(&pkt, s->init_msg, len)) {
634 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
635 return SUB_STATE_ERROR;
637 ret = process_message(s, &pkt);
639 /* Discard the packet data */
643 case MSG_PROCESS_ERROR:
645 return SUB_STATE_ERROR;
647 case MSG_PROCESS_FINISHED_READING:
648 if (SSL_IS_DTLS(s)) {
651 return SUB_STATE_FINISHED;
653 case MSG_PROCESS_CONTINUE_PROCESSING:
654 st->read_state = READ_STATE_POST_PROCESS;
655 st->read_state_work = WORK_MORE_A;
659 st->read_state = READ_STATE_HEADER;
664 case READ_STATE_POST_PROCESS:
665 st->read_state_work = post_process_message(s, st->read_state_work);
666 switch (st->read_state_work) {
673 return SUB_STATE_ERROR;
675 case WORK_FINISHED_CONTINUE:
676 st->read_state = READ_STATE_HEADER;
679 case WORK_FINISHED_STOP:
680 if (SSL_IS_DTLS(s)) {
683 return SUB_STATE_FINISHED;
688 /* Shouldn't happen */
689 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
690 return SUB_STATE_ERROR;
696 * Send a previously constructed message to the peer.
698 static int statem_do_write(SSL *s)
700 OSSL_STATEM *st = &s->statem;
702 if (st->hand_state == TLS_ST_CW_CHANGE
703 || st->hand_state == TLS_ST_SW_CHANGE) {
705 return dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
707 return ssl3_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
709 return ssl_do_write(s);
714 * Initialise the MSG_FLOW_WRITING sub-state machine
716 static void init_write_state_machine(SSL *s)
718 OSSL_STATEM *st = &s->statem;
720 st->write_state = WRITE_STATE_TRANSITION;
724 * This function implements the sub-state machine when the message flow is in
725 * MSG_FLOW_WRITING. The valid sub-states and transitions are:
727 * +-> WRITE_STATE_TRANSITION ------> [SUB_STATE_FINISHED]
730 * | WRITE_STATE_PRE_WORK -----> [SUB_STATE_END_HANDSHAKE]
736 * | WRITE_STATE_POST_WORK
740 * WRITE_STATE_TRANSITION transitions the state of the handshake state machine
742 * WRITE_STATE_PRE_WORK performs any work necessary to prepare the later
743 * sending of the message. This could result in an NBIO event occurring in
744 * which case control returns to the calling application. When this function
745 * is recalled we will resume in the same state where we left off.
747 * WRITE_STATE_SEND sends the message and performs any work to be done after
750 * WRITE_STATE_POST_WORK performs any work necessary after the sending of the
751 * message has been completed. As for WRITE_STATE_PRE_WORK this could also
752 * result in an NBIO event.
754 static SUB_STATE_RETURN write_state_machine(SSL *s)
756 OSSL_STATEM *st = &s->statem;
758 WRITE_TRAN(*transition) (SSL *s);
759 WORK_STATE(*pre_work) (SSL *s, WORK_STATE wst);
760 WORK_STATE(*post_work) (SSL *s, WORK_STATE wst);
761 int (*get_construct_message_f) (SSL *s, WPACKET *pkt,
762 int (**confunc) (SSL *s, WPACKET *pkt),
764 void (*cb) (const SSL *ssl, int type, int val) = NULL;
765 int (*confunc) (SSL *s, WPACKET *pkt);
769 cb = get_callback(s);
772 transition = ossl_statem_server_write_transition;
773 pre_work = ossl_statem_server_pre_work;
774 post_work = ossl_statem_server_post_work;
775 get_construct_message_f = ossl_statem_server_construct_message;
777 transition = ossl_statem_client_write_transition;
778 pre_work = ossl_statem_client_pre_work;
779 post_work = ossl_statem_client_post_work;
780 get_construct_message_f = ossl_statem_client_construct_message;
784 switch (st->write_state) {
785 case WRITE_STATE_TRANSITION:
787 /* Notify callback of an impending state change */
789 cb(s, SSL_CB_ACCEPT_LOOP, 1);
791 cb(s, SSL_CB_CONNECT_LOOP, 1);
793 switch (transition(s)) {
794 case WRITE_TRAN_CONTINUE:
795 st->write_state = WRITE_STATE_PRE_WORK;
796 st->write_state_work = WORK_MORE_A;
799 case WRITE_TRAN_FINISHED:
800 return SUB_STATE_FINISHED;
803 case WRITE_TRAN_ERROR:
805 return SUB_STATE_ERROR;
809 case WRITE_STATE_PRE_WORK:
810 switch (st->write_state_work = pre_work(s, st->write_state_work)) {
817 return SUB_STATE_ERROR;
819 case WORK_FINISHED_CONTINUE:
820 st->write_state = WRITE_STATE_SEND;
823 case WORK_FINISHED_STOP:
824 return SUB_STATE_END_HANDSHAKE;
826 if (!get_construct_message_f(s, &pkt, &confunc, &mt)) {
827 /* SSLfatal() already called */
828 return SUB_STATE_ERROR;
830 if (mt == SSL3_MT_DUMMY) {
831 /* Skip construction and sending. This isn't a "real" state */
832 st->write_state = WRITE_STATE_POST_WORK;
833 st->write_state_work = WORK_MORE_A;
836 if (!WPACKET_init(&pkt, s->init_buf)
837 || !ssl_set_handshake_header(s, &pkt, mt)) {
838 WPACKET_cleanup(&pkt);
839 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
840 return SUB_STATE_ERROR;
842 if (confunc != NULL && !confunc(s, &pkt)) {
843 WPACKET_cleanup(&pkt);
845 return SUB_STATE_ERROR;
847 if (!ssl_close_construct_packet(s, &pkt, mt)
848 || !WPACKET_finish(&pkt)) {
849 WPACKET_cleanup(&pkt);
850 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
851 return SUB_STATE_ERROR;
856 case WRITE_STATE_SEND:
857 if (SSL_IS_DTLS(s) && st->use_timer) {
858 dtls1_start_timer(s);
860 ret = statem_do_write(s);
862 return SUB_STATE_ERROR;
864 st->write_state = WRITE_STATE_POST_WORK;
865 st->write_state_work = WORK_MORE_A;
868 case WRITE_STATE_POST_WORK:
869 switch (st->write_state_work = post_work(s, st->write_state_work)) {
876 return SUB_STATE_ERROR;
878 case WORK_FINISHED_CONTINUE:
879 st->write_state = WRITE_STATE_TRANSITION;
882 case WORK_FINISHED_STOP:
883 return SUB_STATE_END_HANDSHAKE;
888 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
889 return SUB_STATE_ERROR;
895 * Flush the write BIO
897 int statem_flush(SSL *s)
899 s->rwstate = SSL_WRITING;
900 if (BIO_flush(s->wbio) <= 0) {
903 s->rwstate = SSL_NOTHING;
909 * Called by the record layer to determine whether application data is
910 * allowed to be received in the current handshake state or not.
913 * 1: Yes (application data allowed)
914 * 0: No (application data not allowed)
916 int ossl_statem_app_data_allowed(SSL *s)
918 OSSL_STATEM *st = &s->statem;
920 if (st->state == MSG_FLOW_UNINITED)
923 if (!s->s3.in_read_app_data || (s->s3.total_renegotiations == 0))
928 * If we're a server and we haven't got as far as writing our
929 * ServerHello yet then we allow app data
931 if (st->hand_state == TLS_ST_BEFORE
932 || st->hand_state == TLS_ST_SR_CLNT_HELLO)
936 * If we're a client and we haven't read the ServerHello yet then we
939 if (st->hand_state == TLS_ST_CW_CLNT_HELLO)
947 * This function returns 1 if TLS exporter is ready to export keying
948 * material, or 0 if otherwise.
950 int ossl_statem_export_allowed(SSL *s)
952 return s->s3.previous_server_finished_len != 0
953 && s->statem.hand_state != TLS_ST_SW_FINISHED;
957 * Return 1 if early TLS exporter is ready to export keying material,
960 int ossl_statem_export_early_allowed(SSL *s)
963 * The early exporter secret is only present on the server if we
964 * have accepted early_data. It is present on the client as long
965 * as we have sent early_data.
967 return s->ext.early_data == SSL_EARLY_DATA_ACCEPTED
968 || (!s->server && s->ext.early_data != SSL_EARLY_DATA_NOT_SENT);