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;
133 s
->statem
.ignore_fatal
= 0;
137 * Set the state machine up ready for a renegotiation handshake
139 void ossl_statem_set_renegotiate(SSL_CONNECTION
*s
)
141 ossl_statem_set_in_init(s
, 1);
142 s
->statem
.request_state
= TLS_ST_SW_HELLO_REQ
;
145 void ossl_statem_send_fatal(SSL_CONNECTION
*s
, int al
)
148 * Some public APIs may call internal functions that fatal error,
149 * which doesn't make sense outside the state machine. Those APIs
150 * that can handle a failure set this flag to avoid errors sending
151 * alerts. Example: getting a wire-formatted certificate for
154 if (s
->statem
.ignore_fatal
)
156 /* We shouldn't call SSLfatal() twice. Once is enough */
157 if (s
->statem
.in_init
&& s
->statem
.state
== MSG_FLOW_ERROR
)
159 ossl_statem_set_in_init(s
, 1);
160 s
->statem
.state
= MSG_FLOW_ERROR
;
161 if (al
!= SSL_AD_NO_ALERT
)
162 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
166 * Error reporting building block that's used instead of ERR_set_error().
167 * In addition to what ERR_set_error() does, this puts the state machine
168 * into an error state and sends an alert if appropriate.
169 * This is a permanent error for the current connection.
171 void ossl_statem_fatal(SSL_CONNECTION
*s
, int al
, int reason
,
172 const char *fmt
, ...)
177 ERR_vset_error(ERR_LIB_SSL
, reason
, fmt
, args
);
180 ossl_statem_send_fatal(s
, al
);
184 * This macro should only be called if we are already expecting to be in
185 * a fatal error state. We verify that we are, and set it if not (this would
188 #define check_fatal(s) \
190 if (!ossl_assert((s)->statem.in_init \
191 && (s)->statem.state == MSG_FLOW_ERROR)) \
192 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_MISSING_FATAL); \
196 * Discover whether the current connection is in the error state.
198 * Valid return values are:
202 int ossl_statem_in_error(const SSL_CONNECTION
*s
)
204 if (s
->statem
.state
== MSG_FLOW_ERROR
)
210 void ossl_statem_set_in_init(SSL_CONNECTION
*s
, int init
)
212 s
->statem
.in_init
= init
;
213 if (s
->rlayer
.rrlmethod
!= NULL
&& s
->rlayer
.rrlmethod
->set_in_init
!= NULL
)
214 s
->rlayer
.rrlmethod
->set_in_init(s
->rlayer
.rrl
, init
);
217 int ossl_statem_get_in_handshake(SSL_CONNECTION
*s
)
219 return s
->statem
.in_handshake
;
222 void ossl_statem_set_in_handshake(SSL_CONNECTION
*s
, int inhand
)
225 s
->statem
.in_handshake
++;
227 s
->statem
.in_handshake
--;
230 /* Are we in a sensible state to skip over unreadable early data? */
231 int ossl_statem_skip_early_data(SSL_CONNECTION
*s
)
233 if (s
->ext
.early_data
!= SSL_EARLY_DATA_REJECTED
)
237 || s
->statem
.hand_state
!= TLS_ST_EARLY_DATA
238 || s
->hello_retry_request
== SSL_HRR_COMPLETE
)
245 * Called when we are in SSL_read*(), SSL_write*(), or SSL_accept()
246 * /SSL_connect()/SSL_do_handshake(). Used to test whether we are in an early
247 * data state and whether we should attempt to move the handshake on if so.
248 * |sending| is 1 if we are attempting to send data (SSL_write*()), 0 if we are
249 * attempting to read data (SSL_read*()), or -1 if we are in SSL_do_handshake()
252 void ossl_statem_check_finish_init(SSL_CONNECTION
*s
, int sending
)
255 if (s
->statem
.hand_state
== TLS_ST_PENDING_EARLY_DATA_END
256 || s
->statem
.hand_state
== TLS_ST_EARLY_DATA
) {
257 ossl_statem_set_in_init(s
, 1);
258 if (s
->early_data_state
== SSL_EARLY_DATA_WRITE_RETRY
) {
260 * SSL_connect() or SSL_do_handshake() has been called directly.
261 * We don't allow any more writing of early data.
263 s
->early_data_state
= SSL_EARLY_DATA_FINISHED_WRITING
;
266 } else if (!s
->server
) {
267 if ((sending
&& (s
->statem
.hand_state
== TLS_ST_PENDING_EARLY_DATA_END
268 || s
->statem
.hand_state
== TLS_ST_EARLY_DATA
)
269 && s
->early_data_state
!= SSL_EARLY_DATA_WRITING
)
270 || (!sending
&& s
->statem
.hand_state
== TLS_ST_EARLY_DATA
)) {
271 ossl_statem_set_in_init(s
, 1);
273 * SSL_write() has been called directly. We don't allow any more
274 * writing of early data.
276 if (sending
&& s
->early_data_state
== SSL_EARLY_DATA_WRITE_RETRY
)
277 s
->early_data_state
= SSL_EARLY_DATA_FINISHED_WRITING
;
280 if (s
->early_data_state
== SSL_EARLY_DATA_FINISHED_READING
281 && s
->statem
.hand_state
== TLS_ST_EARLY_DATA
)
282 ossl_statem_set_in_init(s
, 1);
286 void ossl_statem_set_hello_verify_done(SSL_CONNECTION
*s
)
288 s
->statem
.state
= MSG_FLOW_UNINITED
;
289 ossl_statem_set_in_init(s
, 1);
291 * This will get reset (briefly) back to TLS_ST_BEFORE when we enter
292 * state_machine() because |state| is MSG_FLOW_UNINITED, but until then any
293 * calls to SSL_in_before() will return false. Also calls to
294 * SSL_state_string() and SSL_state_string_long() will return something
297 s
->statem
.hand_state
= TLS_ST_SR_CLNT_HELLO
;
300 int ossl_statem_connect(SSL
*s
)
302 SSL_CONNECTION
*sc
= SSL_CONNECTION_FROM_SSL(s
);
307 return state_machine(sc
, 0);
310 int ossl_statem_accept(SSL
*s
)
312 SSL_CONNECTION
*sc
= SSL_CONNECTION_FROM_SSL(s
);
317 return state_machine(sc
, 1);
320 typedef void (*info_cb
) (const SSL
*, int, int);
322 static info_cb
get_callback(SSL_CONNECTION
*s
)
324 SSL_CTX
*sctx
= SSL_CONNECTION_GET_CTX(s
);
326 if (s
->info_callback
!= NULL
)
327 return s
->info_callback
;
328 else if (sctx
->info_callback
!= NULL
)
329 return sctx
->info_callback
;
335 * The main message flow state machine. We start in the MSG_FLOW_UNINITED or
336 * MSG_FLOW_FINISHED state and finish in MSG_FLOW_FINISHED. Valid states and
337 * transitions are as follows:
339 * MSG_FLOW_UNINITED MSG_FLOW_FINISHED
341 * +-----------------------+
343 * MSG_FLOW_WRITING <---> MSG_FLOW_READING
351 * We may exit at any point due to an error or NBIO event. If an NBIO event
352 * occurs then we restart at the point we left off when we are recalled.
353 * MSG_FLOW_WRITING and MSG_FLOW_READING have sub-state machines associated with them.
355 * In addition to the above there is also the MSG_FLOW_ERROR state. We can move
356 * into that state at any point in the event that an irrecoverable error occurs.
358 * Valid return values are:
362 static int state_machine(SSL_CONNECTION
*s
, int server
)
365 void (*cb
) (const SSL
*ssl
, int type
, int val
) = NULL
;
366 OSSL_STATEM
*st
= &s
->statem
;
369 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
371 if (st
->state
== MSG_FLOW_ERROR
) {
372 /* Shouldn't have been called if we're already in the error state */
379 cb
= get_callback(s
);
382 if (!SSL_in_init(ssl
) || SSL_in_before(ssl
)) {
384 * If we are stateless then we already called SSL_clear() - don't do
385 * it again and clear the STATELESS flag itself.
387 if ((s
->s3
.flags
& TLS1_FLAGS_STATELESS
) == 0 && !SSL_clear(ssl
))
390 #ifndef OPENSSL_NO_SCTP
391 if (SSL_CONNECTION_IS_DTLS(s
) && BIO_dgram_is_sctp(SSL_get_wbio(ssl
))) {
393 * Notify SCTP BIO socket to enter handshake mode and prevent stream
394 * identifier other than 0.
396 BIO_ctrl(SSL_get_wbio(ssl
), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE
,
397 st
->in_handshake
, NULL
);
401 /* Initialise state machine */
402 if (st
->state
== MSG_FLOW_UNINITED
403 || st
->state
== MSG_FLOW_FINISHED
) {
404 if (st
->state
== MSG_FLOW_UNINITED
) {
405 st
->hand_state
= TLS_ST_BEFORE
;
406 st
->request_state
= TLS_ST_BEFORE
;
411 if (SSL_IS_FIRST_HANDSHAKE(s
) || !SSL_CONNECTION_IS_TLS13(s
))
412 cb(ssl
, SSL_CB_HANDSHAKE_START
, 1);
416 * Fatal errors in this block don't send an alert because we have
417 * failed to even initialise properly. Sending an alert is probably
421 if (SSL_CONNECTION_IS_DTLS(s
)) {
422 if ((s
->version
& 0xff00) != (DTLS1_VERSION
& 0xff00) &&
423 (server
|| (s
->version
& 0xff00) != (DTLS1_BAD_VER
& 0xff00))) {
424 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
428 if ((s
->version
>> 8) != SSL3_VERSION_MAJOR
) {
429 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
434 if (!ssl_security(s
, SSL_SECOP_VERSION
, 0, s
->version
, NULL
)) {
435 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
439 if (s
->init_buf
== NULL
) {
440 if ((buf
= BUF_MEM_new()) == NULL
) {
441 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
444 if (!BUF_MEM_grow(buf
, SSL3_RT_MAX_PLAIN_LENGTH
)) {
445 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
452 if (!ssl3_setup_buffers(s
)) {
453 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
459 * Should have been reset by tls_process_finished, too.
461 s
->s3
.change_cipher_spec
= 0;
464 * Ok, we now need to push on a buffering BIO ...but not with
467 #ifndef OPENSSL_NO_SCTP
468 if (!SSL_CONNECTION_IS_DTLS(s
) || !BIO_dgram_is_sctp(SSL_get_wbio(ssl
)))
470 if (!ssl_init_wbio_buffer(s
)) {
471 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
475 if ((SSL_in_before(ssl
))
477 if (!tls_setup_handshake(s
)) {
478 /* SSLfatal() already called */
482 if (SSL_IS_FIRST_HANDSHAKE(s
))
483 st
->read_state_first_init
= 1;
486 st
->state
= MSG_FLOW_WRITING
;
487 init_write_state_machine(s
);
490 while (st
->state
!= MSG_FLOW_FINISHED
) {
491 if (st
->state
== MSG_FLOW_READING
) {
492 ssret
= read_state_machine(s
);
493 if (ssret
== SUB_STATE_FINISHED
) {
494 st
->state
= MSG_FLOW_WRITING
;
495 init_write_state_machine(s
);
500 } else if (st
->state
== MSG_FLOW_WRITING
) {
501 ssret
= write_state_machine(s
);
502 if (ssret
== SUB_STATE_FINISHED
) {
503 st
->state
= MSG_FLOW_READING
;
504 init_read_state_machine(s
);
505 } else if (ssret
== SUB_STATE_END_HANDSHAKE
) {
506 st
->state
= MSG_FLOW_FINISHED
;
514 ERR_raise(ERR_LIB_SSL
, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED
);
524 #ifndef OPENSSL_NO_SCTP
525 if (SSL_CONNECTION_IS_DTLS(s
) && BIO_dgram_is_sctp(SSL_get_wbio(ssl
))) {
527 * Notify SCTP BIO socket to leave handshake mode and allow stream
528 * identifier other than 0.
530 BIO_ctrl(SSL_get_wbio(ssl
), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE
,
531 st
->in_handshake
, NULL
);
538 cb(ssl
, SSL_CB_ACCEPT_EXIT
, ret
);
540 cb(ssl
, SSL_CB_CONNECT_EXIT
, ret
);
546 * Initialise the MSG_FLOW_READING sub-state machine
548 static void init_read_state_machine(SSL_CONNECTION
*s
)
550 OSSL_STATEM
*st
= &s
->statem
;
552 st
->read_state
= READ_STATE_HEADER
;
555 static int grow_init_buf(SSL_CONNECTION
*s
, size_t size
) {
557 size_t msg_offset
= (char *)s
->init_msg
- s
->init_buf
->data
;
559 if (!BUF_MEM_grow_clean(s
->init_buf
, (int)size
))
562 if (size
< msg_offset
)
565 s
->init_msg
= s
->init_buf
->data
+ msg_offset
;
571 * This function implements the sub-state machine when the message flow is in
572 * MSG_FLOW_READING. The valid sub-states and transitions are:
574 * READ_STATE_HEADER <--+<-------------+
577 * READ_STATE_BODY -----+-->READ_STATE_POST_PROCESS
579 * +----------------------------+
581 * [SUB_STATE_FINISHED]
583 * READ_STATE_HEADER has the responsibility for reading in the message header
584 * and transitioning the state of the handshake state machine.
586 * READ_STATE_BODY reads in the rest of the message and then subsequently
589 * READ_STATE_POST_PROCESS is an optional step that may occur if some post
590 * processing activity performed on the message may block.
592 * Any of the above states could result in an NBIO event occurring in which case
593 * control returns to the calling application. When this function is recalled we
594 * will resume in the same state where we left off.
596 static SUB_STATE_RETURN
read_state_machine(SSL_CONNECTION
*s
)
598 OSSL_STATEM
*st
= &s
->statem
;
601 int (*transition
) (SSL_CONNECTION
*s
, int mt
);
603 MSG_PROCESS_RETURN(*process_message
) (SSL_CONNECTION
*s
, PACKET
*pkt
);
604 WORK_STATE(*post_process_message
) (SSL_CONNECTION
*s
, WORK_STATE wst
);
605 size_t (*max_message_size
) (SSL_CONNECTION
*s
);
606 void (*cb
) (const SSL
*ssl
, int type
, int val
) = NULL
;
607 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
609 cb
= get_callback(s
);
612 transition
= ossl_statem_server_read_transition
;
613 process_message
= ossl_statem_server_process_message
;
614 max_message_size
= ossl_statem_server_max_message_size
;
615 post_process_message
= ossl_statem_server_post_process_message
;
617 transition
= ossl_statem_client_read_transition
;
618 process_message
= ossl_statem_client_process_message
;
619 max_message_size
= ossl_statem_client_max_message_size
;
620 post_process_message
= ossl_statem_client_post_process_message
;
623 if (st
->read_state_first_init
) {
625 st
->read_state_first_init
= 0;
629 switch (st
->read_state
) {
630 case READ_STATE_HEADER
:
631 /* Get the state the peer wants to move to */
632 if (SSL_CONNECTION_IS_DTLS(s
)) {
634 * In DTLS we get the whole message in one go - header and body
636 ret
= dtls_get_message(s
, &mt
);
638 ret
= tls_get_message_header(s
, &mt
);
642 /* Could be non-blocking IO */
643 return SUB_STATE_ERROR
;
647 /* Notify callback of an impending state change */
649 cb(ssl
, SSL_CB_ACCEPT_LOOP
, 1);
651 cb(ssl
, SSL_CB_CONNECT_LOOP
, 1);
654 * Validate that we are allowed to move to the new state and move
655 * to that state if so
657 if (!transition(s
, mt
))
658 return SUB_STATE_ERROR
;
660 if (s
->s3
.tmp
.message_size
> max_message_size(s
)) {
661 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
,
662 SSL_R_EXCESSIVE_MESSAGE_SIZE
);
663 return SUB_STATE_ERROR
;
666 /* dtls_get_message already did this */
667 if (!SSL_CONNECTION_IS_DTLS(s
)
668 && s
->s3
.tmp
.message_size
> 0
669 && !grow_init_buf(s
, s
->s3
.tmp
.message_size
670 + SSL3_HM_HEADER_LENGTH
)) {
671 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_BUF_LIB
);
672 return SUB_STATE_ERROR
;
675 st
->read_state
= READ_STATE_BODY
;
678 case READ_STATE_BODY
:
679 if (SSL_CONNECTION_IS_DTLS(s
)) {
681 * Actually we already have the body, but we give DTLS the
682 * opportunity to do any further processing.
684 ret
= dtls_get_message_body(s
, &len
);
686 ret
= tls_get_message_body(s
, &len
);
689 /* Could be non-blocking IO */
690 return SUB_STATE_ERROR
;
694 if (!PACKET_buf_init(&pkt
, s
->init_msg
, len
)) {
695 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
696 return SUB_STATE_ERROR
;
698 ret
= process_message(s
, &pkt
);
700 /* Discard the packet data */
704 case MSG_PROCESS_ERROR
:
706 return SUB_STATE_ERROR
;
708 case MSG_PROCESS_FINISHED_READING
:
709 if (SSL_CONNECTION_IS_DTLS(s
)) {
712 return SUB_STATE_FINISHED
;
714 case MSG_PROCESS_CONTINUE_PROCESSING
:
715 st
->read_state
= READ_STATE_POST_PROCESS
;
716 st
->read_state_work
= WORK_MORE_A
;
720 st
->read_state
= READ_STATE_HEADER
;
725 case READ_STATE_POST_PROCESS
:
726 st
->read_state_work
= post_process_message(s
, st
->read_state_work
);
727 switch (st
->read_state_work
) {
734 return SUB_STATE_ERROR
;
736 case WORK_FINISHED_CONTINUE
:
737 st
->read_state
= READ_STATE_HEADER
;
740 case WORK_FINISHED_STOP
:
741 if (SSL_CONNECTION_IS_DTLS(s
)) {
744 return SUB_STATE_FINISHED
;
749 /* Shouldn't happen */
750 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
751 return SUB_STATE_ERROR
;
757 * Send a previously constructed message to the peer.
759 static int statem_do_write(SSL_CONNECTION
*s
)
761 OSSL_STATEM
*st
= &s
->statem
;
763 if (st
->hand_state
== TLS_ST_CW_CHANGE
764 || st
->hand_state
== TLS_ST_SW_CHANGE
) {
765 if (SSL_CONNECTION_IS_DTLS(s
))
766 return dtls1_do_write(s
, SSL3_RT_CHANGE_CIPHER_SPEC
);
768 return ssl3_do_write(s
, SSL3_RT_CHANGE_CIPHER_SPEC
);
770 return ssl_do_write(s
);
775 * Initialise the MSG_FLOW_WRITING sub-state machine
777 static void init_write_state_machine(SSL_CONNECTION
*s
)
779 OSSL_STATEM
*st
= &s
->statem
;
781 st
->write_state
= WRITE_STATE_TRANSITION
;
785 * This function implements the sub-state machine when the message flow is in
786 * MSG_FLOW_WRITING. The valid sub-states and transitions are:
788 * +-> WRITE_STATE_TRANSITION ------> [SUB_STATE_FINISHED]
791 * | WRITE_STATE_PRE_WORK -----> [SUB_STATE_END_HANDSHAKE]
797 * | WRITE_STATE_POST_WORK
801 * WRITE_STATE_TRANSITION transitions the state of the handshake state machine
803 * WRITE_STATE_PRE_WORK performs any work necessary to prepare the later
804 * sending of the message. This could result in an NBIO event occurring in
805 * which case control returns to the calling application. When this function
806 * is recalled we will resume in the same state where we left off.
808 * WRITE_STATE_SEND sends the message and performs any work to be done after
811 * WRITE_STATE_POST_WORK performs any work necessary after the sending of the
812 * message has been completed. As for WRITE_STATE_PRE_WORK this could also
813 * result in an NBIO event.
815 static SUB_STATE_RETURN
write_state_machine(SSL_CONNECTION
*s
)
817 OSSL_STATEM
*st
= &s
->statem
;
819 WRITE_TRAN(*transition
) (SSL_CONNECTION
*s
);
820 WORK_STATE(*pre_work
) (SSL_CONNECTION
*s
, WORK_STATE wst
);
821 WORK_STATE(*post_work
) (SSL_CONNECTION
*s
, WORK_STATE wst
);
822 int (*get_construct_message_f
) (SSL_CONNECTION
*s
,
823 CON_FUNC_RETURN (**confunc
) (SSL_CONNECTION
*s
,
826 void (*cb
) (const SSL
*ssl
, int type
, int val
) = NULL
;
827 CON_FUNC_RETURN (*confunc
) (SSL_CONNECTION
*s
, WPACKET
*pkt
);
830 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
832 cb
= get_callback(s
);
835 transition
= ossl_statem_server_write_transition
;
836 pre_work
= ossl_statem_server_pre_work
;
837 post_work
= ossl_statem_server_post_work
;
838 get_construct_message_f
= ossl_statem_server_construct_message
;
840 transition
= ossl_statem_client_write_transition
;
841 pre_work
= ossl_statem_client_pre_work
;
842 post_work
= ossl_statem_client_post_work
;
843 get_construct_message_f
= ossl_statem_client_construct_message
;
847 switch (st
->write_state
) {
848 case WRITE_STATE_TRANSITION
:
850 /* Notify callback of an impending state change */
852 cb(ssl
, SSL_CB_ACCEPT_LOOP
, 1);
854 cb(ssl
, SSL_CB_CONNECT_LOOP
, 1);
856 switch (transition(s
)) {
857 case WRITE_TRAN_CONTINUE
:
858 st
->write_state
= WRITE_STATE_PRE_WORK
;
859 st
->write_state_work
= WORK_MORE_A
;
862 case WRITE_TRAN_FINISHED
:
863 return SUB_STATE_FINISHED
;
866 case WRITE_TRAN_ERROR
:
868 return SUB_STATE_ERROR
;
872 case WRITE_STATE_PRE_WORK
:
873 switch (st
->write_state_work
= pre_work(s
, st
->write_state_work
)) {
880 return SUB_STATE_ERROR
;
882 case WORK_FINISHED_CONTINUE
:
883 st
->write_state
= WRITE_STATE_SEND
;
886 case WORK_FINISHED_STOP
:
887 return SUB_STATE_END_HANDSHAKE
;
889 if (!get_construct_message_f(s
, &confunc
, &mt
)) {
890 /* SSLfatal() already called */
891 return SUB_STATE_ERROR
;
893 if (mt
== SSL3_MT_DUMMY
) {
894 /* Skip construction and sending. This isn't a "real" state */
895 st
->write_state
= WRITE_STATE_POST_WORK
;
896 st
->write_state_work
= WORK_MORE_A
;
899 if (!WPACKET_init(&pkt
, s
->init_buf
)
900 || !ssl_set_handshake_header(s
, &pkt
, mt
)) {
901 WPACKET_cleanup(&pkt
);
902 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
903 return SUB_STATE_ERROR
;
905 if (confunc
!= NULL
) {
906 CON_FUNC_RETURN tmpret
;
908 tmpret
= confunc(s
, &pkt
);
909 if (tmpret
== CON_FUNC_ERROR
) {
910 WPACKET_cleanup(&pkt
);
912 return SUB_STATE_ERROR
;
913 } else if (tmpret
== CON_FUNC_DONT_SEND
) {
915 * The construction function decided not to construct the
916 * message after all and continue. Skip sending.
918 WPACKET_cleanup(&pkt
);
919 st
->write_state
= WRITE_STATE_POST_WORK
;
920 st
->write_state_work
= WORK_MORE_A
;
924 if (!ssl_close_construct_packet(s
, &pkt
, mt
)
925 || !WPACKET_finish(&pkt
)) {
926 WPACKET_cleanup(&pkt
);
927 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
928 return SUB_STATE_ERROR
;
933 case WRITE_STATE_SEND
:
934 if (SSL_CONNECTION_IS_DTLS(s
) && st
->use_timer
) {
935 dtls1_start_timer(s
);
937 ret
= statem_do_write(s
);
939 return SUB_STATE_ERROR
;
941 st
->write_state
= WRITE_STATE_POST_WORK
;
942 st
->write_state_work
= WORK_MORE_A
;
945 case WRITE_STATE_POST_WORK
:
946 switch (st
->write_state_work
= post_work(s
, st
->write_state_work
)) {
953 return SUB_STATE_ERROR
;
955 case WORK_FINISHED_CONTINUE
:
956 st
->write_state
= WRITE_STATE_TRANSITION
;
959 case WORK_FINISHED_STOP
:
960 return SUB_STATE_END_HANDSHAKE
;
965 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
966 return SUB_STATE_ERROR
;
972 * Flush the write BIO
974 int statem_flush(SSL_CONNECTION
*s
)
976 s
->rwstate
= SSL_WRITING
;
977 if (BIO_flush(s
->wbio
) <= 0) {
980 s
->rwstate
= SSL_NOTHING
;
986 * Called by the record layer to determine whether application data is
987 * allowed to be received in the current handshake state or not.
990 * 1: Yes (application data allowed)
991 * 0: No (application data not allowed)
993 int ossl_statem_app_data_allowed(SSL_CONNECTION
*s
)
995 OSSL_STATEM
*st
= &s
->statem
;
997 if (st
->state
== MSG_FLOW_UNINITED
)
1000 if (!s
->s3
.in_read_app_data
|| (s
->s3
.total_renegotiations
== 0))
1005 * If we're a server and we haven't got as far as writing our
1006 * ServerHello yet then we allow app data
1008 if (st
->hand_state
== TLS_ST_BEFORE
1009 || st
->hand_state
== TLS_ST_SR_CLNT_HELLO
)
1013 * If we're a client and we haven't read the ServerHello yet then we
1016 if (st
->hand_state
== TLS_ST_CW_CLNT_HELLO
)
1024 * This function returns 1 if TLS exporter is ready to export keying
1025 * material, or 0 if otherwise.
1027 int ossl_statem_export_allowed(SSL_CONNECTION
*s
)
1029 return s
->s3
.previous_server_finished_len
!= 0
1030 && s
->statem
.hand_state
!= TLS_ST_SW_FINISHED
;
1034 * Return 1 if early TLS exporter is ready to export keying material,
1035 * or 0 if otherwise.
1037 int ossl_statem_export_early_allowed(SSL_CONNECTION
*s
)
1040 * The early exporter secret is only present on the server if we
1041 * have accepted early_data. It is present on the client as long
1042 * as we have sent early_data.
1044 return s
->ext
.early_data
== SSL_EARLY_DATA_ACCEPTED
1045 || (!s
->server
&& s
->ext
.early_data
!= SSL_EARLY_DATA_NOT_SENT
);