2 * Copyright 2015-2022 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 #if defined(__TANDEM) && defined(_SPT_MODEL_)
11 # include <spthread.h>
12 # include <spt_extensions.h> /* timeval */
15 #include "internal/cryptlib.h"
16 #include <openssl/rand.h>
17 #include "../ssl_local.h"
18 #include "statem_local.h"
22 * This file implements the SSL/TLS/DTLS state machines.
24 * There are two primary state machines:
26 * 1) Message flow state machine
27 * 2) Handshake state machine
29 * The Message flow state machine controls the reading and sending of messages
30 * including handling of non-blocking IO events, flushing of the underlying
31 * write BIO, handling unexpected messages, etc. It is itself broken into two
32 * separate sub-state machines which control reading and writing respectively.
34 * The Handshake state machine keeps track of the current SSL/TLS handshake
35 * state. Transitions of the handshake state are the result of events that
36 * occur within the Message flow state machine.
38 * Overall it looks like this:
40 * --------------------------------------------- -------------------
42 * | Message flow state machine | | |
44 * | -------------------- -------------------- | Transition | Handshake state |
45 * | | MSG_FLOW_READING | | MSG_FLOW_WRITING | | Event | machine |
46 * | | sub-state | | sub-state | |----------->| |
47 * | | machine for | | machine for | | | |
48 * | | reading messages | | writing messages | | | |
49 * | -------------------- -------------------- | | |
51 * --------------------------------------------- -------------------
55 /* Sub state machine return values */
57 /* Something bad happened or NBIO */
59 /* Sub state finished go to the next sub state */
61 /* Sub state finished and handshake was completed */
62 SUB_STATE_END_HANDSHAKE
65 static int state_machine(SSL_CONNECTION *s, int server);
66 static void init_read_state_machine(SSL_CONNECTION *s);
67 static SUB_STATE_RETURN read_state_machine(SSL_CONNECTION *s);
68 static void init_write_state_machine(SSL_CONNECTION *s);
69 static SUB_STATE_RETURN write_state_machine(SSL_CONNECTION *s);
71 OSSL_HANDSHAKE_STATE SSL_get_state(const SSL *ssl)
73 const SSL_CONNECTION *sc = SSL_CONNECTION_FROM_CONST_SSL(ssl);
78 return sc->statem.hand_state;
81 int SSL_in_init(const SSL *s)
83 const SSL_CONNECTION *sc = SSL_CONNECTION_FROM_CONST_SSL(s);
88 return sc->statem.in_init;
91 int SSL_is_init_finished(const SSL *s)
93 const SSL_CONNECTION *sc = SSL_CONNECTION_FROM_CONST_SSL(s);
98 return !(sc->statem.in_init) && (sc->statem.hand_state == TLS_ST_OK);
101 int SSL_in_before(const SSL *s)
103 const SSL_CONNECTION *sc = SSL_CONNECTION_FROM_CONST_SSL(s);
109 * Historically being "in before" meant before anything had happened. In the
110 * current code though we remain in the "before" state for a while after we
111 * have started the handshake process (e.g. as a server waiting for the
112 * first message to arrive). There "in before" is taken to mean "in before"
113 * and not started any handshake process yet.
115 return (sc->statem.hand_state == TLS_ST_BEFORE)
116 && (sc->statem.state == MSG_FLOW_UNINITED);
119 OSSL_HANDSHAKE_STATE ossl_statem_get_state(SSL_CONNECTION *s)
121 return s != NULL ? s->statem.hand_state : TLS_ST_BEFORE;
125 * Clear the state machine state and reset back to MSG_FLOW_UNINITED
127 void ossl_statem_clear(SSL_CONNECTION *s)
129 s->statem.state = MSG_FLOW_UNINITED;
130 s->statem.hand_state = TLS_ST_BEFORE;
131 ossl_statem_set_in_init(s, 1);
132 s->statem.no_cert_verify = 0;
136 * Set the state machine up ready for a renegotiation handshake
138 void ossl_statem_set_renegotiate(SSL_CONNECTION *s)
140 ossl_statem_set_in_init(s, 1);
141 s->statem.request_state = TLS_ST_SW_HELLO_REQ;
144 void ossl_statem_send_fatal(SSL_CONNECTION *s, int al)
146 /* We shouldn't call SSLfatal() twice. Once is enough */
147 if (s->statem.in_init && s->statem.state == MSG_FLOW_ERROR)
149 ossl_statem_set_in_init(s, 1);
150 s->statem.state = MSG_FLOW_ERROR;
151 if (al != SSL_AD_NO_ALERT)
152 ssl3_send_alert(s, SSL3_AL_FATAL, al);
156 * Error reporting building block that's used instead of ERR_set_error().
157 * In addition to what ERR_set_error() does, this puts the state machine
158 * into an error state and sends an alert if appropriate.
159 * This is a permanent error for the current connection.
161 void ossl_statem_fatal(SSL_CONNECTION *s, int al, int reason,
162 const char *fmt, ...)
167 ERR_vset_error(ERR_LIB_SSL, reason, fmt, args);
170 ossl_statem_send_fatal(s, al);
174 * This macro should only be called if we are already expecting to be in
175 * a fatal error state. We verify that we are, and set it if not (this would
178 #define check_fatal(s) \
180 if (!ossl_assert((s)->statem.in_init \
181 && (s)->statem.state == MSG_FLOW_ERROR)) \
182 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_MISSING_FATAL); \
186 * Discover whether the current connection is in the error state.
188 * Valid return values are:
192 int ossl_statem_in_error(const SSL_CONNECTION *s)
194 if (s->statem.state == MSG_FLOW_ERROR)
200 void ossl_statem_set_in_init(SSL_CONNECTION *s, int init)
202 s->statem.in_init = init;
203 if (s->rlayer.rrlmethod != NULL && s->rlayer.rrlmethod->set_in_init != NULL)
204 s->rlayer.rrlmethod->set_in_init(s->rlayer.rrl, init);
207 int ossl_statem_get_in_handshake(SSL_CONNECTION *s)
209 return s->statem.in_handshake;
212 void ossl_statem_set_in_handshake(SSL_CONNECTION *s, int inhand)
215 s->statem.in_handshake++;
217 s->statem.in_handshake--;
220 /* Are we in a sensible state to skip over unreadable early data? */
221 int ossl_statem_skip_early_data(SSL_CONNECTION *s)
223 if (s->ext.early_data != SSL_EARLY_DATA_REJECTED)
227 || s->statem.hand_state != TLS_ST_EARLY_DATA
228 || s->hello_retry_request == SSL_HRR_COMPLETE)
235 * Called when we are in SSL_read*(), SSL_write*(), or SSL_accept()
236 * /SSL_connect()/SSL_do_handshake(). Used to test whether we are in an early
237 * data state and whether we should attempt to move the handshake on if so.
238 * |sending| is 1 if we are attempting to send data (SSL_write*()), 0 if we are
239 * attempting to read data (SSL_read*()), or -1 if we are in SSL_do_handshake()
242 void ossl_statem_check_finish_init(SSL_CONNECTION *s, int sending)
245 if (s->statem.hand_state == TLS_ST_PENDING_EARLY_DATA_END
246 || s->statem.hand_state == TLS_ST_EARLY_DATA) {
247 ossl_statem_set_in_init(s, 1);
248 if (s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) {
250 * SSL_connect() or SSL_do_handshake() has been called directly.
251 * We don't allow any more writing of early data.
253 s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
256 } else if (!s->server) {
257 if ((sending && (s->statem.hand_state == TLS_ST_PENDING_EARLY_DATA_END
258 || s->statem.hand_state == TLS_ST_EARLY_DATA)
259 && s->early_data_state != SSL_EARLY_DATA_WRITING)
260 || (!sending && s->statem.hand_state == TLS_ST_EARLY_DATA)) {
261 ossl_statem_set_in_init(s, 1);
263 * SSL_write() has been called directly. We don't allow any more
264 * writing of early data.
266 if (sending && s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY)
267 s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
270 if (s->early_data_state == SSL_EARLY_DATA_FINISHED_READING
271 && s->statem.hand_state == TLS_ST_EARLY_DATA)
272 ossl_statem_set_in_init(s, 1);
276 void ossl_statem_set_hello_verify_done(SSL_CONNECTION *s)
278 s->statem.state = MSG_FLOW_UNINITED;
279 ossl_statem_set_in_init(s, 1);
281 * This will get reset (briefly) back to TLS_ST_BEFORE when we enter
282 * state_machine() because |state| is MSG_FLOW_UNINITED, but until then any
283 * calls to SSL_in_before() will return false. Also calls to
284 * SSL_state_string() and SSL_state_string_long() will return something
287 s->statem.hand_state = TLS_ST_SR_CLNT_HELLO;
290 int ossl_statem_connect(SSL *s)
292 SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL(s);
297 return state_machine(sc, 0);
300 int ossl_statem_accept(SSL *s)
302 SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL(s);
307 return state_machine(sc, 1);
310 typedef void (*info_cb) (const SSL *, int, int);
312 static info_cb get_callback(SSL_CONNECTION *s)
314 SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
316 if (s->info_callback != NULL)
317 return s->info_callback;
318 else if (sctx->info_callback != NULL)
319 return sctx->info_callback;
325 * The main message flow state machine. We start in the MSG_FLOW_UNINITED or
326 * MSG_FLOW_FINISHED state and finish in MSG_FLOW_FINISHED. Valid states and
327 * transitions are as follows:
329 * MSG_FLOW_UNINITED MSG_FLOW_FINISHED
331 * +-----------------------+
333 * MSG_FLOW_WRITING <---> MSG_FLOW_READING
341 * We may exit at any point due to an error or NBIO event. If an NBIO event
342 * occurs then we restart at the point we left off when we are recalled.
343 * MSG_FLOW_WRITING and MSG_FLOW_READING have sub-state machines associated with them.
345 * In addition to the above there is also the MSG_FLOW_ERROR state. We can move
346 * into that state at any point in the event that an irrecoverable error occurs.
348 * Valid return values are:
352 static int state_machine(SSL_CONNECTION *s, int server)
355 void (*cb) (const SSL *ssl, int type, int val) = NULL;
356 OSSL_STATEM *st = &s->statem;
359 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
361 if (st->state == MSG_FLOW_ERROR) {
362 /* Shouldn't have been called if we're already in the error state */
369 cb = get_callback(s);
372 if (!SSL_in_init(ssl) || SSL_in_before(ssl)) {
374 * If we are stateless then we already called SSL_clear() - don't do
375 * it again and clear the STATELESS flag itself.
377 if ((s->s3.flags & TLS1_FLAGS_STATELESS) == 0 && !SSL_clear(ssl))
380 #ifndef OPENSSL_NO_SCTP
381 if (SSL_CONNECTION_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(ssl))) {
383 * Notify SCTP BIO socket to enter handshake mode and prevent stream
384 * identifier other than 0.
386 BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
387 st->in_handshake, NULL);
391 /* Initialise state machine */
392 if (st->state == MSG_FLOW_UNINITED
393 || st->state == MSG_FLOW_FINISHED) {
394 if (st->state == MSG_FLOW_UNINITED) {
395 st->hand_state = TLS_ST_BEFORE;
396 st->request_state = TLS_ST_BEFORE;
401 if (SSL_IS_FIRST_HANDSHAKE(s) || !SSL_CONNECTION_IS_TLS13(s))
402 cb(ssl, SSL_CB_HANDSHAKE_START, 1);
406 * Fatal errors in this block don't send an alert because we have
407 * failed to even initialise properly. Sending an alert is probably
411 if (SSL_CONNECTION_IS_DTLS(s)) {
412 if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
413 (server || (s->version & 0xff00) != (DTLS1_BAD_VER & 0xff00))) {
414 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
418 if ((s->version >> 8) != SSL3_VERSION_MAJOR) {
419 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
424 if (!ssl_security(s, SSL_SECOP_VERSION, 0, s->version, NULL)) {
425 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
429 if (s->init_buf == NULL) {
430 if ((buf = BUF_MEM_new()) == NULL) {
431 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
434 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
435 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
445 * Should have been reset by tls_process_finished, too.
447 s->s3.change_cipher_spec = 0;
450 * Ok, we now need to push on a buffering BIO ...but not with
453 #ifndef OPENSSL_NO_SCTP
454 if (!SSL_CONNECTION_IS_DTLS(s) || !BIO_dgram_is_sctp(SSL_get_wbio(ssl)))
456 if (!ssl_init_wbio_buffer(s)) {
457 SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR);
461 if ((SSL_in_before(ssl))
463 if (!tls_setup_handshake(s)) {
464 /* SSLfatal() already called */
468 if (SSL_IS_FIRST_HANDSHAKE(s))
469 st->read_state_first_init = 1;
472 st->state = MSG_FLOW_WRITING;
473 init_write_state_machine(s);
476 while (st->state != MSG_FLOW_FINISHED) {
477 if (st->state == MSG_FLOW_READING) {
478 ssret = read_state_machine(s);
479 if (ssret == SUB_STATE_FINISHED) {
480 st->state = MSG_FLOW_WRITING;
481 init_write_state_machine(s);
486 } else if (st->state == MSG_FLOW_WRITING) {
487 ssret = write_state_machine(s);
488 if (ssret == SUB_STATE_FINISHED) {
489 st->state = MSG_FLOW_READING;
490 init_read_state_machine(s);
491 } else if (ssret == SUB_STATE_END_HANDSHAKE) {
492 st->state = MSG_FLOW_FINISHED;
500 ERR_raise(ERR_LIB_SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
510 #ifndef OPENSSL_NO_SCTP
511 if (SSL_CONNECTION_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(ssl))) {
513 * Notify SCTP BIO socket to leave handshake mode and allow stream
514 * identifier other than 0.
516 BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
517 st->in_handshake, NULL);
524 cb(ssl, SSL_CB_ACCEPT_EXIT, ret);
526 cb(ssl, SSL_CB_CONNECT_EXIT, ret);
532 * Initialise the MSG_FLOW_READING sub-state machine
534 static void init_read_state_machine(SSL_CONNECTION *s)
536 OSSL_STATEM *st = &s->statem;
538 st->read_state = READ_STATE_HEADER;
541 static int grow_init_buf(SSL_CONNECTION *s, size_t size) {
543 size_t msg_offset = (char *)s->init_msg - s->init_buf->data;
545 if (!BUF_MEM_grow_clean(s->init_buf, (int)size))
548 if (size < msg_offset)
551 s->init_msg = s->init_buf->data + msg_offset;
557 * This function implements the sub-state machine when the message flow is in
558 * MSG_FLOW_READING. The valid sub-states and transitions are:
560 * READ_STATE_HEADER <--+<-------------+
563 * READ_STATE_BODY -----+-->READ_STATE_POST_PROCESS
565 * +----------------------------+
567 * [SUB_STATE_FINISHED]
569 * READ_STATE_HEADER has the responsibility for reading in the message header
570 * and transitioning the state of the handshake state machine.
572 * READ_STATE_BODY reads in the rest of the message and then subsequently
575 * READ_STATE_POST_PROCESS is an optional step that may occur if some post
576 * processing activity performed on the message may block.
578 * Any of the above states could result in an NBIO event occurring in which case
579 * control returns to the calling application. When this function is recalled we
580 * will resume in the same state where we left off.
582 static SUB_STATE_RETURN read_state_machine(SSL_CONNECTION *s)
584 OSSL_STATEM *st = &s->statem;
587 int (*transition) (SSL_CONNECTION *s, int mt);
589 MSG_PROCESS_RETURN(*process_message) (SSL_CONNECTION *s, PACKET *pkt);
590 WORK_STATE(*post_process_message) (SSL_CONNECTION *s, WORK_STATE wst);
591 size_t (*max_message_size) (SSL_CONNECTION *s);
592 void (*cb) (const SSL *ssl, int type, int val) = NULL;
593 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
595 cb = get_callback(s);
598 transition = ossl_statem_server_read_transition;
599 process_message = ossl_statem_server_process_message;
600 max_message_size = ossl_statem_server_max_message_size;
601 post_process_message = ossl_statem_server_post_process_message;
603 transition = ossl_statem_client_read_transition;
604 process_message = ossl_statem_client_process_message;
605 max_message_size = ossl_statem_client_max_message_size;
606 post_process_message = ossl_statem_client_post_process_message;
609 if (st->read_state_first_init) {
611 st->read_state_first_init = 0;
615 switch (st->read_state) {
616 case READ_STATE_HEADER:
617 /* Get the state the peer wants to move to */
618 if (SSL_CONNECTION_IS_DTLS(s)) {
620 * In DTLS we get the whole message in one go - header and body
622 ret = dtls_get_message(s, &mt);
624 ret = tls_get_message_header(s, &mt);
628 /* Could be non-blocking IO */
629 return SUB_STATE_ERROR;
633 /* Notify callback of an impending state change */
635 cb(ssl, SSL_CB_ACCEPT_LOOP, 1);
637 cb(ssl, SSL_CB_CONNECT_LOOP, 1);
640 * Validate that we are allowed to move to the new state and move
641 * to that state if so
643 if (!transition(s, mt))
644 return SUB_STATE_ERROR;
646 if (s->s3.tmp.message_size > max_message_size(s)) {
647 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
648 SSL_R_EXCESSIVE_MESSAGE_SIZE);
649 return SUB_STATE_ERROR;
652 /* dtls_get_message already did this */
653 if (!SSL_CONNECTION_IS_DTLS(s)
654 && s->s3.tmp.message_size > 0
655 && !grow_init_buf(s, s->s3.tmp.message_size
656 + SSL3_HM_HEADER_LENGTH)) {
657 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_BUF_LIB);
658 return SUB_STATE_ERROR;
661 st->read_state = READ_STATE_BODY;
664 case READ_STATE_BODY:
665 if (SSL_CONNECTION_IS_DTLS(s)) {
667 * Actually we already have the body, but we give DTLS the
668 * opportunity to do any further processing.
670 ret = dtls_get_message_body(s, &len);
672 ret = tls_get_message_body(s, &len);
675 /* Could be non-blocking IO */
676 return SUB_STATE_ERROR;
680 if (!PACKET_buf_init(&pkt, s->init_msg, len)) {
681 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
682 return SUB_STATE_ERROR;
684 ret = process_message(s, &pkt);
686 /* Discard the packet data */
690 case MSG_PROCESS_ERROR:
692 return SUB_STATE_ERROR;
694 case MSG_PROCESS_FINISHED_READING:
695 if (SSL_CONNECTION_IS_DTLS(s)) {
698 return SUB_STATE_FINISHED;
700 case MSG_PROCESS_CONTINUE_PROCESSING:
701 st->read_state = READ_STATE_POST_PROCESS;
702 st->read_state_work = WORK_MORE_A;
706 st->read_state = READ_STATE_HEADER;
711 case READ_STATE_POST_PROCESS:
712 st->read_state_work = post_process_message(s, st->read_state_work);
713 switch (st->read_state_work) {
720 return SUB_STATE_ERROR;
722 case WORK_FINISHED_CONTINUE:
723 st->read_state = READ_STATE_HEADER;
726 case WORK_FINISHED_STOP:
727 if (SSL_CONNECTION_IS_DTLS(s)) {
730 return SUB_STATE_FINISHED;
735 /* Shouldn't happen */
736 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
737 return SUB_STATE_ERROR;
743 * Send a previously constructed message to the peer.
745 static int statem_do_write(SSL_CONNECTION *s)
747 OSSL_STATEM *st = &s->statem;
749 if (st->hand_state == TLS_ST_CW_CHANGE
750 || st->hand_state == TLS_ST_SW_CHANGE) {
751 if (SSL_CONNECTION_IS_DTLS(s))
752 return dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
754 return ssl3_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
756 return ssl_do_write(s);
761 * Initialise the MSG_FLOW_WRITING sub-state machine
763 static void init_write_state_machine(SSL_CONNECTION *s)
765 OSSL_STATEM *st = &s->statem;
767 st->write_state = WRITE_STATE_TRANSITION;
771 * This function implements the sub-state machine when the message flow is in
772 * MSG_FLOW_WRITING. The valid sub-states and transitions are:
774 * +-> WRITE_STATE_TRANSITION ------> [SUB_STATE_FINISHED]
777 * | WRITE_STATE_PRE_WORK -----> [SUB_STATE_END_HANDSHAKE]
783 * | WRITE_STATE_POST_WORK
787 * WRITE_STATE_TRANSITION transitions the state of the handshake state machine
789 * WRITE_STATE_PRE_WORK performs any work necessary to prepare the later
790 * sending of the message. This could result in an NBIO event occurring in
791 * which case control returns to the calling application. When this function
792 * is recalled we will resume in the same state where we left off.
794 * WRITE_STATE_SEND sends the message and performs any work to be done after
797 * WRITE_STATE_POST_WORK performs any work necessary after the sending of the
798 * message has been completed. As for WRITE_STATE_PRE_WORK this could also
799 * result in an NBIO event.
801 static SUB_STATE_RETURN write_state_machine(SSL_CONNECTION *s)
803 OSSL_STATEM *st = &s->statem;
805 WRITE_TRAN(*transition) (SSL_CONNECTION *s);
806 WORK_STATE(*pre_work) (SSL_CONNECTION *s, WORK_STATE wst);
807 WORK_STATE(*post_work) (SSL_CONNECTION *s, WORK_STATE wst);
808 int (*get_construct_message_f) (SSL_CONNECTION *s,
809 CON_FUNC_RETURN (**confunc) (SSL_CONNECTION *s,
812 void (*cb) (const SSL *ssl, int type, int val) = NULL;
813 CON_FUNC_RETURN (*confunc) (SSL_CONNECTION *s, WPACKET *pkt);
816 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
818 cb = get_callback(s);
821 transition = ossl_statem_server_write_transition;
822 pre_work = ossl_statem_server_pre_work;
823 post_work = ossl_statem_server_post_work;
824 get_construct_message_f = ossl_statem_server_construct_message;
826 transition = ossl_statem_client_write_transition;
827 pre_work = ossl_statem_client_pre_work;
828 post_work = ossl_statem_client_post_work;
829 get_construct_message_f = ossl_statem_client_construct_message;
833 switch (st->write_state) {
834 case WRITE_STATE_TRANSITION:
836 /* Notify callback of an impending state change */
838 cb(ssl, SSL_CB_ACCEPT_LOOP, 1);
840 cb(ssl, SSL_CB_CONNECT_LOOP, 1);
842 switch (transition(s)) {
843 case WRITE_TRAN_CONTINUE:
844 st->write_state = WRITE_STATE_PRE_WORK;
845 st->write_state_work = WORK_MORE_A;
848 case WRITE_TRAN_FINISHED:
849 return SUB_STATE_FINISHED;
852 case WRITE_TRAN_ERROR:
854 return SUB_STATE_ERROR;
858 case WRITE_STATE_PRE_WORK:
859 switch (st->write_state_work = pre_work(s, st->write_state_work)) {
866 return SUB_STATE_ERROR;
868 case WORK_FINISHED_CONTINUE:
869 st->write_state = WRITE_STATE_SEND;
872 case WORK_FINISHED_STOP:
873 return SUB_STATE_END_HANDSHAKE;
875 if (!get_construct_message_f(s, &confunc, &mt)) {
876 /* SSLfatal() already called */
877 return SUB_STATE_ERROR;
879 if (mt == SSL3_MT_DUMMY) {
880 /* Skip construction and sending. This isn't a "real" state */
881 st->write_state = WRITE_STATE_POST_WORK;
882 st->write_state_work = WORK_MORE_A;
885 if (!WPACKET_init(&pkt, s->init_buf)
886 || !ssl_set_handshake_header(s, &pkt, mt)) {
887 WPACKET_cleanup(&pkt);
888 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
889 return SUB_STATE_ERROR;
891 if (confunc != NULL) {
892 CON_FUNC_RETURN tmpret;
894 tmpret = confunc(s, &pkt);
895 if (tmpret == CON_FUNC_ERROR) {
896 WPACKET_cleanup(&pkt);
898 return SUB_STATE_ERROR;
899 } else if (tmpret == CON_FUNC_DONT_SEND) {
901 * The construction function decided not to construct the
902 * message after all and continue. Skip sending.
904 WPACKET_cleanup(&pkt);
905 st->write_state = WRITE_STATE_POST_WORK;
906 st->write_state_work = WORK_MORE_A;
910 if (!ssl_close_construct_packet(s, &pkt, mt)
911 || !WPACKET_finish(&pkt)) {
912 WPACKET_cleanup(&pkt);
913 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
914 return SUB_STATE_ERROR;
919 case WRITE_STATE_SEND:
920 if (SSL_CONNECTION_IS_DTLS(s) && st->use_timer) {
921 dtls1_start_timer(s);
923 ret = statem_do_write(s);
925 return SUB_STATE_ERROR;
927 st->write_state = WRITE_STATE_POST_WORK;
928 st->write_state_work = WORK_MORE_A;
931 case WRITE_STATE_POST_WORK:
932 switch (st->write_state_work = post_work(s, st->write_state_work)) {
939 return SUB_STATE_ERROR;
941 case WORK_FINISHED_CONTINUE:
942 st->write_state = WRITE_STATE_TRANSITION;
945 case WORK_FINISHED_STOP:
946 return SUB_STATE_END_HANDSHAKE;
951 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
952 return SUB_STATE_ERROR;
958 * Flush the write BIO
960 int statem_flush(SSL_CONNECTION *s)
962 s->rwstate = SSL_WRITING;
963 if (BIO_flush(s->wbio) <= 0) {
966 s->rwstate = SSL_NOTHING;
972 * Called by the record layer to determine whether application data is
973 * allowed to be received in the current handshake state or not.
976 * 1: Yes (application data allowed)
977 * 0: No (application data not allowed)
979 int ossl_statem_app_data_allowed(SSL_CONNECTION *s)
981 OSSL_STATEM *st = &s->statem;
983 if (st->state == MSG_FLOW_UNINITED)
986 if (!s->s3.in_read_app_data || (s->s3.total_renegotiations == 0))
991 * If we're a server and we haven't got as far as writing our
992 * ServerHello yet then we allow app data
994 if (st->hand_state == TLS_ST_BEFORE
995 || st->hand_state == TLS_ST_SR_CLNT_HELLO)
999 * If we're a client and we haven't read the ServerHello yet then we
1002 if (st->hand_state == TLS_ST_CW_CLNT_HELLO)
1010 * This function returns 1 if TLS exporter is ready to export keying
1011 * material, or 0 if otherwise.
1013 int ossl_statem_export_allowed(SSL_CONNECTION *s)
1015 return s->s3.previous_server_finished_len != 0
1016 && s->statem.hand_state != TLS_ST_SW_FINISHED;
1020 * Return 1 if early TLS exporter is ready to export keying material,
1021 * or 0 if otherwise.
1023 int ossl_statem_export_early_allowed(SSL_CONNECTION *s)
1026 * The early exporter secret is only present on the server if we
1027 * have accepted early_data. It is present on the client as long
1028 * as we have sent early_data.
1030 return s->ext.early_data == SSL_EARLY_DATA_ACCEPTED
1031 || (!s->server && s->ext.early_data != SSL_EARLY_DATA_NOT_SENT);