2 * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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_locl.h"
13 #include "statem_locl.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(SSL *s)
73 return s->statem.in_init;
76 int SSL_is_init_finished(SSL *s)
78 return !(s->statem.in_init) && (s->statem.hand_state == TLS_ST_OK);
81 int SSL_in_before(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;
115 * Put the state machine into an error state and send an alert if appropriate.
116 * This is a permanent error for the current connection.
118 void ossl_statem_fatal(SSL *s, int al, int func, int reason, const char *file,
121 /* We shouldn't call SSLfatal() twice. Once is enough */
122 assert(s->statem.state != MSG_FLOW_ERROR);
123 s->statem.in_init = 1;
124 s->statem.state = MSG_FLOW_ERROR;
125 ERR_put_error(ERR_LIB_SSL, func, reason, file, line);
126 if (al != SSL_AD_NO_ALERT && !s->statem.invalid_enc_write_ctx)
127 ssl3_send_alert(s, SSL3_AL_FATAL, al);
131 * This macro should only be called if we are already expecting to be in
132 * a fatal error state. We verify that we are, and set it if not (this would
135 #define check_fatal(s, f) \
137 if (!ossl_assert((s)->statem.in_init \
138 && (s)->statem.state == MSG_FLOW_ERROR)) \
139 SSLfatal(s, SSL_AD_INTERNAL_ERROR, (f), \
140 SSL_R_MISSING_FATAL); \
144 * Discover whether the current connection is in the error state.
146 * Valid return values are:
150 int ossl_statem_in_error(const SSL *s)
152 if (s->statem.state == MSG_FLOW_ERROR)
158 void ossl_statem_set_in_init(SSL *s, int init)
160 s->statem.in_init = init;
163 int ossl_statem_get_in_handshake(SSL *s)
165 return s->statem.in_handshake;
168 void ossl_statem_set_in_handshake(SSL *s, int inhand)
171 s->statem.in_handshake++;
173 s->statem.in_handshake--;
176 /* Are we in a sensible state to skip over unreadable early data? */
177 int ossl_statem_skip_early_data(SSL *s)
179 if (s->ext.early_data != SSL_EARLY_DATA_REJECTED)
182 if (!s->server || s->statem.hand_state != TLS_ST_EARLY_DATA)
189 * Called when we are in SSL_read*(), SSL_write*(), or SSL_accept()
190 * /SSL_connect()/SSL_do_handshake(). Used to test whether we are in an early
191 * data state and whether we should attempt to move the handshake on if so.
192 * |sending| is 1 if we are attempting to send data (SSL_write*()), 0 if we are
193 * attempting to read data (SSL_read*()), or -1 if we are in SSL_do_handshake()
196 void ossl_statem_check_finish_init(SSL *s, int sending)
199 if (s->statem.hand_state == TLS_ST_PENDING_EARLY_DATA_END
200 || s->statem.hand_state == TLS_ST_EARLY_DATA) {
201 ossl_statem_set_in_init(s, 1);
202 if (s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) {
204 * SSL_connect() or SSL_do_handshake() has been called directly.
205 * We don't allow any more writing of early data.
207 s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
210 } else if (!s->server) {
211 if ((sending && (s->statem.hand_state == TLS_ST_PENDING_EARLY_DATA_END
212 || s->statem.hand_state == TLS_ST_EARLY_DATA)
213 && s->early_data_state != SSL_EARLY_DATA_WRITING)
214 || (!sending && s->statem.hand_state == TLS_ST_EARLY_DATA)) {
215 ossl_statem_set_in_init(s, 1);
217 * SSL_write() has been called directly. We don't allow any more
218 * writing of early data.
220 if (sending && s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY)
221 s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
224 if (s->early_data_state == SSL_EARLY_DATA_FINISHED_READING
225 && s->statem.hand_state == TLS_ST_EARLY_DATA)
226 ossl_statem_set_in_init(s, 1);
230 void ossl_statem_set_hello_verify_done(SSL *s)
232 s->statem.state = MSG_FLOW_UNINITED;
233 s->statem.in_init = 1;
235 * This will get reset (briefly) back to TLS_ST_BEFORE when we enter
236 * state_machine() because |state| is MSG_FLOW_UNINITED, but until then any
237 * calls to SSL_in_before() will return false. Also calls to
238 * SSL_state_string() and SSL_state_string_long() will return something
241 s->statem.hand_state = TLS_ST_SR_CLNT_HELLO;
244 int ossl_statem_connect(SSL *s)
246 return state_machine(s, 0);
249 int ossl_statem_accept(SSL *s)
251 return state_machine(s, 1);
254 typedef void (*info_cb) (const SSL *, int, int);
256 static info_cb get_callback(SSL *s)
258 if (s->info_callback != NULL)
259 return s->info_callback;
260 else if (s->ctx->info_callback != NULL)
261 return s->ctx->info_callback;
267 * The main message flow state machine. We start in the MSG_FLOW_UNINITED or
268 * MSG_FLOW_FINISHED state and finish in MSG_FLOW_FINISHED. Valid states and
269 * transitions are as follows:
271 * MSG_FLOW_UNINITED MSG_FLOW_FINISHED
273 * +-----------------------+
275 * MSG_FLOW_WRITING <---> MSG_FLOW_READING
283 * We may exit at any point due to an error or NBIO event. If an NBIO event
284 * occurs then we restart at the point we left off when we are recalled.
285 * MSG_FLOW_WRITING and MSG_FLOW_READING have sub-state machines associated with them.
287 * In addition to the above there is also the MSG_FLOW_ERROR state. We can move
288 * into that state at any point in the event that an irrecoverable error occurs.
290 * Valid return values are:
294 static int state_machine(SSL *s, int server)
297 void (*cb) (const SSL *ssl, int type, int val) = NULL;
298 OSSL_STATEM *st = &s->statem;
302 if (st->state == MSG_FLOW_ERROR) {
303 /* Shouldn't have been called if we're already in the error state */
310 cb = get_callback(s);
313 if (!SSL_in_init(s) || SSL_in_before(s)) {
315 * If we are stateless then we already called SSL_clear() - don't do
316 * it again and clear the STATELESS flag itself.
318 if ((s->s3->flags & TLS1_FLAGS_STATELESS) == 0 && !SSL_clear(s))
321 #ifndef OPENSSL_NO_SCTP
322 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
324 * Notify SCTP BIO socket to enter handshake mode and prevent stream
325 * identifier other than 0.
327 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
328 st->in_handshake, NULL);
332 /* Initialise state machine */
333 if (st->state == MSG_FLOW_UNINITED
334 || st->state == MSG_FLOW_FINISHED) {
335 if (st->state == MSG_FLOW_UNINITED) {
336 st->hand_state = TLS_ST_BEFORE;
337 st->request_state = TLS_ST_BEFORE;
342 cb(s, SSL_CB_HANDSHAKE_START, 1);
345 * Fatal errors in this block don't send an alert because we have
346 * failed to even initialise properly. Sending an alert is probably
350 if (SSL_IS_DTLS(s)) {
351 if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
352 (server || (s->version & 0xff00) != (DTLS1_BAD_VER & 0xff00))) {
353 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE,
354 ERR_R_INTERNAL_ERROR);
358 if ((s->version >> 8) != SSL3_VERSION_MAJOR) {
359 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE,
360 ERR_R_INTERNAL_ERROR);
365 if (!ssl_security(s, SSL_SECOP_VERSION, 0, s->version, NULL)) {
366 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE,
367 ERR_R_INTERNAL_ERROR);
371 if (s->init_buf == NULL) {
372 if ((buf = BUF_MEM_new()) == NULL) {
373 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE,
374 ERR_R_INTERNAL_ERROR);
377 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
378 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE,
379 ERR_R_INTERNAL_ERROR);
386 if (!ssl3_setup_buffers(s)) {
387 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE,
388 ERR_R_INTERNAL_ERROR);
394 * Should have been reset by tls_process_finished, too.
396 s->s3->change_cipher_spec = 0;
399 * Ok, we now need to push on a buffering BIO ...but not with
402 #ifndef OPENSSL_NO_SCTP
403 if (!SSL_IS_DTLS(s) || !BIO_dgram_is_sctp(SSL_get_wbio(s)))
405 if (!ssl_init_wbio_buffer(s)) {
406 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE,
407 ERR_R_INTERNAL_ERROR);
411 if ((SSL_in_before(s))
413 if (!tls_setup_handshake(s)) {
414 /* SSLfatal() already called */
418 if (SSL_IS_FIRST_HANDSHAKE(s))
419 st->read_state_first_init = 1;
422 st->state = MSG_FLOW_WRITING;
423 init_write_state_machine(s);
426 while (st->state != MSG_FLOW_FINISHED) {
427 if (st->state == MSG_FLOW_READING) {
428 ssret = read_state_machine(s);
429 if (ssret == SUB_STATE_FINISHED) {
430 st->state = MSG_FLOW_WRITING;
431 init_write_state_machine(s);
436 } else if (st->state == MSG_FLOW_WRITING) {
437 ssret = write_state_machine(s);
438 if (ssret == SUB_STATE_FINISHED) {
439 st->state = MSG_FLOW_READING;
440 init_read_state_machine(s);
441 } else if (ssret == SUB_STATE_END_HANDSHAKE) {
442 st->state = MSG_FLOW_FINISHED;
449 check_fatal(s, SSL_F_STATE_MACHINE);
450 SSLerr(SSL_F_STATE_MACHINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
460 #ifndef OPENSSL_NO_SCTP
461 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
463 * Notify SCTP BIO socket to leave handshake mode and allow stream
464 * identifier other than 0.
466 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
467 st->in_handshake, NULL);
474 cb(s, SSL_CB_ACCEPT_EXIT, ret);
476 cb(s, SSL_CB_CONNECT_EXIT, ret);
482 * Initialise the MSG_FLOW_READING sub-state machine
484 static void init_read_state_machine(SSL *s)
486 OSSL_STATEM *st = &s->statem;
488 st->read_state = READ_STATE_HEADER;
491 static int grow_init_buf(SSL *s, size_t size) {
493 size_t msg_offset = (char *)s->init_msg - s->init_buf->data;
495 if (!BUF_MEM_grow_clean(s->init_buf, (int)size))
498 if (size < msg_offset)
501 s->init_msg = s->init_buf->data + msg_offset;
507 * This function implements the sub-state machine when the message flow is in
508 * MSG_FLOW_READING. The valid sub-states and transitions are:
510 * READ_STATE_HEADER <--+<-------------+
513 * READ_STATE_BODY -----+-->READ_STATE_POST_PROCESS
515 * +----------------------------+
517 * [SUB_STATE_FINISHED]
519 * READ_STATE_HEADER has the responsibility for reading in the message header
520 * and transitioning the state of the handshake state machine.
522 * READ_STATE_BODY reads in the rest of the message and then subsequently
525 * READ_STATE_POST_PROCESS is an optional step that may occur if some post
526 * processing activity performed on the message may block.
528 * Any of the above states could result in an NBIO event occurring in which case
529 * control returns to the calling application. When this function is recalled we
530 * will resume in the same state where we left off.
532 static SUB_STATE_RETURN read_state_machine(SSL *s)
534 OSSL_STATEM *st = &s->statem;
537 int (*transition) (SSL *s, int mt);
539 MSG_PROCESS_RETURN(*process_message) (SSL *s, PACKET *pkt);
540 WORK_STATE(*post_process_message) (SSL *s, WORK_STATE wst);
541 size_t (*max_message_size) (SSL *s);
542 void (*cb) (const SSL *ssl, int type, int val) = NULL;
544 cb = get_callback(s);
547 transition = ossl_statem_server_read_transition;
548 process_message = ossl_statem_server_process_message;
549 max_message_size = ossl_statem_server_max_message_size;
550 post_process_message = ossl_statem_server_post_process_message;
552 transition = ossl_statem_client_read_transition;
553 process_message = ossl_statem_client_process_message;
554 max_message_size = ossl_statem_client_max_message_size;
555 post_process_message = ossl_statem_client_post_process_message;
558 if (st->read_state_first_init) {
560 st->read_state_first_init = 0;
564 switch (st->read_state) {
565 case READ_STATE_HEADER:
566 /* Get the state the peer wants to move to */
567 if (SSL_IS_DTLS(s)) {
569 * In DTLS we get the whole message in one go - header and body
571 ret = dtls_get_message(s, &mt, &len);
573 ret = tls_get_message_header(s, &mt);
577 /* Could be non-blocking IO */
578 return SUB_STATE_ERROR;
582 /* Notify callback of an impending state change */
584 cb(s, SSL_CB_ACCEPT_LOOP, 1);
586 cb(s, SSL_CB_CONNECT_LOOP, 1);
589 * Validate that we are allowed to move to the new state and move
590 * to that state if so
592 if (!transition(s, mt)) {
593 check_fatal(s, SSL_F_READ_STATE_MACHINE);
594 return SUB_STATE_ERROR;
597 if (s->s3->tmp.message_size > max_message_size(s)) {
598 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_READ_STATE_MACHINE,
599 SSL_R_EXCESSIVE_MESSAGE_SIZE);
600 return SUB_STATE_ERROR;
603 /* dtls_get_message already did this */
605 && s->s3->tmp.message_size > 0
606 && !grow_init_buf(s, s->s3->tmp.message_size
607 + SSL3_HM_HEADER_LENGTH)) {
608 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_READ_STATE_MACHINE,
610 return SUB_STATE_ERROR;
613 st->read_state = READ_STATE_BODY;
616 case READ_STATE_BODY:
617 if (!SSL_IS_DTLS(s)) {
618 /* We already got this above for DTLS */
619 ret = tls_get_message_body(s, &len);
621 /* Could be non-blocking IO */
622 return SUB_STATE_ERROR;
627 if (!PACKET_buf_init(&pkt, s->init_msg, len)) {
628 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_READ_STATE_MACHINE,
629 ERR_R_INTERNAL_ERROR);
630 return SUB_STATE_ERROR;
632 ret = process_message(s, &pkt);
634 /* Discard the packet data */
638 case MSG_PROCESS_ERROR:
639 check_fatal(s, SSL_F_READ_STATE_MACHINE);
640 return SUB_STATE_ERROR;
642 case MSG_PROCESS_FINISHED_READING:
643 if (SSL_IS_DTLS(s)) {
646 return SUB_STATE_FINISHED;
648 case MSG_PROCESS_CONTINUE_PROCESSING:
649 st->read_state = READ_STATE_POST_PROCESS;
650 st->read_state_work = WORK_MORE_A;
654 st->read_state = READ_STATE_HEADER;
659 case READ_STATE_POST_PROCESS:
660 st->read_state_work = post_process_message(s, st->read_state_work);
661 switch (st->read_state_work) {
663 check_fatal(s, SSL_F_READ_STATE_MACHINE);
668 return SUB_STATE_ERROR;
670 case WORK_FINISHED_CONTINUE:
671 st->read_state = READ_STATE_HEADER;
674 case WORK_FINISHED_STOP:
675 if (SSL_IS_DTLS(s)) {
678 return SUB_STATE_FINISHED;
683 /* Shouldn't happen */
684 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_READ_STATE_MACHINE,
685 ERR_R_INTERNAL_ERROR);
686 return SUB_STATE_ERROR;
692 * Send a previously constructed message to the peer.
694 static int statem_do_write(SSL *s)
696 OSSL_STATEM *st = &s->statem;
698 if (st->hand_state == TLS_ST_CW_CHANGE
699 || st->hand_state == TLS_ST_SW_CHANGE) {
701 return dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
703 return ssl3_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
705 return ssl_do_write(s);
710 * Initialise the MSG_FLOW_WRITING sub-state machine
712 static void init_write_state_machine(SSL *s)
714 OSSL_STATEM *st = &s->statem;
716 st->write_state = WRITE_STATE_TRANSITION;
720 * This function implements the sub-state machine when the message flow is in
721 * MSG_FLOW_WRITING. The valid sub-states and transitions are:
723 * +-> WRITE_STATE_TRANSITION ------> [SUB_STATE_FINISHED]
726 * | WRITE_STATE_PRE_WORK -----> [SUB_STATE_END_HANDSHAKE]
732 * | WRITE_STATE_POST_WORK
736 * WRITE_STATE_TRANSITION transitions the state of the handshake state machine
738 * WRITE_STATE_PRE_WORK performs any work necessary to prepare the later
739 * sending of the message. This could result in an NBIO event occurring in
740 * which case control returns to the calling application. When this function
741 * is recalled we will resume in the same state where we left off.
743 * WRITE_STATE_SEND sends the message and performs any work to be done after
746 * WRITE_STATE_POST_WORK performs any work necessary after the sending of the
747 * message has been completed. As for WRITE_STATE_PRE_WORK this could also
748 * result in an NBIO event.
750 static SUB_STATE_RETURN write_state_machine(SSL *s)
752 OSSL_STATEM *st = &s->statem;
754 WRITE_TRAN(*transition) (SSL *s);
755 WORK_STATE(*pre_work) (SSL *s, WORK_STATE wst);
756 WORK_STATE(*post_work) (SSL *s, WORK_STATE wst);
757 int (*get_construct_message_f) (SSL *s, WPACKET *pkt,
758 int (**confunc) (SSL *s, WPACKET *pkt),
760 void (*cb) (const SSL *ssl, int type, int val) = NULL;
761 int (*confunc) (SSL *s, WPACKET *pkt);
765 cb = get_callback(s);
768 transition = ossl_statem_server_write_transition;
769 pre_work = ossl_statem_server_pre_work;
770 post_work = ossl_statem_server_post_work;
771 get_construct_message_f = ossl_statem_server_construct_message;
773 transition = ossl_statem_client_write_transition;
774 pre_work = ossl_statem_client_pre_work;
775 post_work = ossl_statem_client_post_work;
776 get_construct_message_f = ossl_statem_client_construct_message;
780 switch (st->write_state) {
781 case WRITE_STATE_TRANSITION:
783 /* Notify callback of an impending state change */
785 cb(s, SSL_CB_ACCEPT_LOOP, 1);
787 cb(s, SSL_CB_CONNECT_LOOP, 1);
789 switch (transition(s)) {
790 case WRITE_TRAN_CONTINUE:
791 st->write_state = WRITE_STATE_PRE_WORK;
792 st->write_state_work = WORK_MORE_A;
795 case WRITE_TRAN_FINISHED:
796 return SUB_STATE_FINISHED;
799 case WRITE_TRAN_ERROR:
800 check_fatal(s, SSL_F_WRITE_STATE_MACHINE);
801 return SUB_STATE_ERROR;
805 case WRITE_STATE_PRE_WORK:
806 switch (st->write_state_work = pre_work(s, st->write_state_work)) {
808 check_fatal(s, SSL_F_WRITE_STATE_MACHINE);
813 return SUB_STATE_ERROR;
815 case WORK_FINISHED_CONTINUE:
816 st->write_state = WRITE_STATE_SEND;
819 case WORK_FINISHED_STOP:
820 return SUB_STATE_END_HANDSHAKE;
822 if (!get_construct_message_f(s, &pkt, &confunc, &mt)) {
823 /* SSLfatal() already called */
824 return SUB_STATE_ERROR;
826 if (mt == SSL3_MT_DUMMY) {
827 /* Skip construction and sending. This isn't a "real" state */
828 st->write_state = WRITE_STATE_POST_WORK;
829 st->write_state_work = WORK_MORE_A;
832 if (!WPACKET_init(&pkt, s->init_buf)
833 || !ssl_set_handshake_header(s, &pkt, mt)) {
834 WPACKET_cleanup(&pkt);
835 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_WRITE_STATE_MACHINE,
836 ERR_R_INTERNAL_ERROR);
837 return SUB_STATE_ERROR;
839 if (confunc != NULL && !confunc(s, &pkt)) {
840 WPACKET_cleanup(&pkt);
841 check_fatal(s, SSL_F_WRITE_STATE_MACHINE);
842 return SUB_STATE_ERROR;
844 if (!ssl_close_construct_packet(s, &pkt, mt)
845 || !WPACKET_finish(&pkt)) {
846 WPACKET_cleanup(&pkt);
847 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_WRITE_STATE_MACHINE,
848 ERR_R_INTERNAL_ERROR);
849 return SUB_STATE_ERROR;
854 case WRITE_STATE_SEND:
855 if (SSL_IS_DTLS(s) && st->use_timer) {
856 dtls1_start_timer(s);
858 ret = statem_do_write(s);
860 return SUB_STATE_ERROR;
862 st->write_state = WRITE_STATE_POST_WORK;
863 st->write_state_work = WORK_MORE_A;
866 case WRITE_STATE_POST_WORK:
867 switch (st->write_state_work = post_work(s, st->write_state_work)) {
869 check_fatal(s, SSL_F_WRITE_STATE_MACHINE);
874 return SUB_STATE_ERROR;
876 case WORK_FINISHED_CONTINUE:
877 st->write_state = WRITE_STATE_TRANSITION;
880 case WORK_FINISHED_STOP:
881 return SUB_STATE_END_HANDSHAKE;
886 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_WRITE_STATE_MACHINE,
887 ERR_R_INTERNAL_ERROR);
888 return SUB_STATE_ERROR;
894 * Flush the write BIO
896 int statem_flush(SSL *s)
898 s->rwstate = SSL_WRITING;
899 if (BIO_flush(s->wbio) <= 0) {
902 s->rwstate = SSL_NOTHING;
908 * Called by the record layer to determine whether application data is
909 * allowed to be received in the current handshake state or not.
912 * 1: Yes (application data allowed)
913 * 0: No (application data not allowed)
915 int ossl_statem_app_data_allowed(SSL *s)
917 OSSL_STATEM *st = &s->statem;
919 if (st->state == MSG_FLOW_UNINITED)
922 if (!s->s3->in_read_app_data || (s->s3->total_renegotiations == 0))
927 * If we're a server and we haven't got as far as writing our
928 * ServerHello yet then we allow app data
930 if (st->hand_state == TLS_ST_BEFORE
931 || st->hand_state == TLS_ST_SR_CLNT_HELLO)
935 * If we're a client and we haven't read the ServerHello yet then we
938 if (st->hand_state == TLS_ST_CW_CLNT_HELLO)
946 * This function returns 1 if TLS exporter is ready to export keying
947 * material, or 0 if otherwise.
949 int ossl_statem_export_allowed(SSL *s)
951 return s->s3->previous_server_finished_len != 0
952 && s->statem.hand_state != TLS_ST_SW_FINISHED;
956 * Return 1 if early TLS exporter is ready to export keying material,
959 int ossl_statem_export_early_allowed(SSL *s)
962 * The early exporter secret is only present on the server if we
963 * have accepted early_data. It is present on the client as long
964 * as we have sent early_data.
966 return s->ext.early_data == SSL_EARLY_DATA_ACCEPTED
967 || (!s->server && s->ext.early_data != SSL_EARLY_DATA_NOT_SENT);