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
);
120 * Clear the state machine state and reset back to MSG_FLOW_UNINITED
122 void ossl_statem_clear(SSL_CONNECTION
*s
)
124 s
->statem
.state
= MSG_FLOW_UNINITED
;
125 s
->statem
.hand_state
= TLS_ST_BEFORE
;
126 ossl_statem_set_in_init(s
, 1);
127 s
->statem
.no_cert_verify
= 0;
131 * Set the state machine up ready for a renegotiation handshake
133 void ossl_statem_set_renegotiate(SSL_CONNECTION
*s
)
135 ossl_statem_set_in_init(s
, 1);
136 s
->statem
.request_state
= TLS_ST_SW_HELLO_REQ
;
139 void ossl_statem_send_fatal(SSL_CONNECTION
*s
, int al
)
141 /* We shouldn't call SSLfatal() twice. Once is enough */
142 if (s
->statem
.in_init
&& s
->statem
.state
== MSG_FLOW_ERROR
)
144 ossl_statem_set_in_init(s
, 1);
145 s
->statem
.state
= MSG_FLOW_ERROR
;
146 if (al
!= SSL_AD_NO_ALERT
147 && s
->statem
.enc_write_state
!= ENC_WRITE_STATE_INVALID
)
148 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
152 * Error reporting building block that's used instead of ERR_set_error().
153 * In addition to what ERR_set_error() does, this puts the state machine
154 * into an error state and sends an alert if appropriate.
155 * This is a permanent error for the current connection.
157 void ossl_statem_fatal(SSL_CONNECTION
*s
, int al
, int reason
,
158 const char *fmt
, ...)
163 ERR_vset_error(ERR_LIB_SSL
, reason
, fmt
, args
);
166 ossl_statem_send_fatal(s
, al
);
170 * This macro should only be called if we are already expecting to be in
171 * a fatal error state. We verify that we are, and set it if not (this would
174 #define check_fatal(s) \
176 if (!ossl_assert((s)->statem.in_init \
177 && (s)->statem.state == MSG_FLOW_ERROR)) \
178 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_MISSING_FATAL); \
182 * Discover whether the current connection is in the error state.
184 * Valid return values are:
188 int ossl_statem_in_error(const SSL_CONNECTION
*s
)
190 if (s
->statem
.state
== MSG_FLOW_ERROR
)
196 void ossl_statem_set_in_init(SSL_CONNECTION
*s
, int init
)
198 s
->statem
.in_init
= init
;
199 if (s
->rlayer
.rrlmethod
!= NULL
&& s
->rlayer
.rrlmethod
->set_in_init
!= NULL
)
200 s
->rlayer
.rrlmethod
->set_in_init(s
->rlayer
.rrl
, init
);
203 int ossl_statem_get_in_handshake(SSL_CONNECTION
*s
)
205 return s
->statem
.in_handshake
;
208 void ossl_statem_set_in_handshake(SSL_CONNECTION
*s
, int inhand
)
211 s
->statem
.in_handshake
++;
213 s
->statem
.in_handshake
--;
216 /* Are we in a sensible state to skip over unreadable early data? */
217 int ossl_statem_skip_early_data(SSL_CONNECTION
*s
)
219 if (s
->ext
.early_data
!= SSL_EARLY_DATA_REJECTED
)
223 || s
->statem
.hand_state
!= TLS_ST_EARLY_DATA
224 || s
->hello_retry_request
== SSL_HRR_COMPLETE
)
231 * Called when we are in SSL_read*(), SSL_write*(), or SSL_accept()
232 * /SSL_connect()/SSL_do_handshake(). Used to test whether we are in an early
233 * data state and whether we should attempt to move the handshake on if so.
234 * |sending| is 1 if we are attempting to send data (SSL_write*()), 0 if we are
235 * attempting to read data (SSL_read*()), or -1 if we are in SSL_do_handshake()
238 void ossl_statem_check_finish_init(SSL_CONNECTION
*s
, int sending
)
241 if (s
->statem
.hand_state
== TLS_ST_PENDING_EARLY_DATA_END
242 || s
->statem
.hand_state
== TLS_ST_EARLY_DATA
) {
243 ossl_statem_set_in_init(s
, 1);
244 if (s
->early_data_state
== SSL_EARLY_DATA_WRITE_RETRY
) {
246 * SSL_connect() or SSL_do_handshake() has been called directly.
247 * We don't allow any more writing of early data.
249 s
->early_data_state
= SSL_EARLY_DATA_FINISHED_WRITING
;
252 } else if (!s
->server
) {
253 if ((sending
&& (s
->statem
.hand_state
== TLS_ST_PENDING_EARLY_DATA_END
254 || s
->statem
.hand_state
== TLS_ST_EARLY_DATA
)
255 && s
->early_data_state
!= SSL_EARLY_DATA_WRITING
)
256 || (!sending
&& s
->statem
.hand_state
== TLS_ST_EARLY_DATA
)) {
257 ossl_statem_set_in_init(s
, 1);
259 * SSL_write() has been called directly. We don't allow any more
260 * writing of early data.
262 if (sending
&& s
->early_data_state
== SSL_EARLY_DATA_WRITE_RETRY
)
263 s
->early_data_state
= SSL_EARLY_DATA_FINISHED_WRITING
;
266 if (s
->early_data_state
== SSL_EARLY_DATA_FINISHED_READING
267 && s
->statem
.hand_state
== TLS_ST_EARLY_DATA
)
268 ossl_statem_set_in_init(s
, 1);
272 void ossl_statem_set_hello_verify_done(SSL_CONNECTION
*s
)
274 s
->statem
.state
= MSG_FLOW_UNINITED
;
275 ossl_statem_set_in_init(s
, 1);
277 * This will get reset (briefly) back to TLS_ST_BEFORE when we enter
278 * state_machine() because |state| is MSG_FLOW_UNINITED, but until then any
279 * calls to SSL_in_before() will return false. Also calls to
280 * SSL_state_string() and SSL_state_string_long() will return something
283 s
->statem
.hand_state
= TLS_ST_SR_CLNT_HELLO
;
286 int ossl_statem_connect(SSL
*s
)
288 SSL_CONNECTION
*sc
= SSL_CONNECTION_FROM_SSL(s
);
293 return state_machine(sc
, 0);
296 int ossl_statem_accept(SSL
*s
)
298 SSL_CONNECTION
*sc
= SSL_CONNECTION_FROM_SSL(s
);
303 return state_machine(sc
, 1);
306 typedef void (*info_cb
) (const SSL
*, int, int);
308 static info_cb
get_callback(SSL_CONNECTION
*s
)
310 SSL_CTX
*sctx
= SSL_CONNECTION_GET_CTX(s
);
312 if (s
->info_callback
!= NULL
)
313 return s
->info_callback
;
314 else if (sctx
->info_callback
!= NULL
)
315 return sctx
->info_callback
;
321 * The main message flow state machine. We start in the MSG_FLOW_UNINITED or
322 * MSG_FLOW_FINISHED state and finish in MSG_FLOW_FINISHED. Valid states and
323 * transitions are as follows:
325 * MSG_FLOW_UNINITED MSG_FLOW_FINISHED
327 * +-----------------------+
329 * MSG_FLOW_WRITING <---> MSG_FLOW_READING
337 * We may exit at any point due to an error or NBIO event. If an NBIO event
338 * occurs then we restart at the point we left off when we are recalled.
339 * MSG_FLOW_WRITING and MSG_FLOW_READING have sub-state machines associated with them.
341 * In addition to the above there is also the MSG_FLOW_ERROR state. We can move
342 * into that state at any point in the event that an irrecoverable error occurs.
344 * Valid return values are:
348 static int state_machine(SSL_CONNECTION
*s
, int server
)
351 void (*cb
) (const SSL
*ssl
, int type
, int val
) = NULL
;
352 OSSL_STATEM
*st
= &s
->statem
;
355 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
357 if (st
->state
== MSG_FLOW_ERROR
) {
358 /* Shouldn't have been called if we're already in the error state */
365 cb
= get_callback(s
);
368 if (!SSL_in_init(ssl
) || SSL_in_before(ssl
)) {
370 * If we are stateless then we already called SSL_clear() - don't do
371 * it again and clear the STATELESS flag itself.
373 if ((s
->s3
.flags
& TLS1_FLAGS_STATELESS
) == 0 && !SSL_clear(ssl
))
376 #ifndef OPENSSL_NO_SCTP
377 if (SSL_CONNECTION_IS_DTLS(s
) && BIO_dgram_is_sctp(SSL_get_wbio(ssl
))) {
379 * Notify SCTP BIO socket to enter handshake mode and prevent stream
380 * identifier other than 0.
382 BIO_ctrl(SSL_get_wbio(ssl
), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE
,
383 st
->in_handshake
, NULL
);
387 /* Initialise state machine */
388 if (st
->state
== MSG_FLOW_UNINITED
389 || st
->state
== MSG_FLOW_FINISHED
) {
390 if (st
->state
== MSG_FLOW_UNINITED
) {
391 st
->hand_state
= TLS_ST_BEFORE
;
392 st
->request_state
= TLS_ST_BEFORE
;
397 if (SSL_IS_FIRST_HANDSHAKE(s
) || !SSL_CONNECTION_IS_TLS13(s
))
398 cb(ssl
, SSL_CB_HANDSHAKE_START
, 1);
402 * Fatal errors in this block don't send an alert because we have
403 * failed to even initialise properly. Sending an alert is probably
407 if (SSL_CONNECTION_IS_DTLS(s
)) {
408 if ((s
->version
& 0xff00) != (DTLS1_VERSION
& 0xff00) &&
409 (server
|| (s
->version
& 0xff00) != (DTLS1_BAD_VER
& 0xff00))) {
410 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
414 if ((s
->version
>> 8) != SSL3_VERSION_MAJOR
) {
415 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
420 if (!ssl_security(s
, SSL_SECOP_VERSION
, 0, s
->version
, NULL
)) {
421 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
425 if (s
->init_buf
== NULL
) {
426 if ((buf
= BUF_MEM_new()) == NULL
) {
427 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
430 if (!BUF_MEM_grow(buf
, SSL3_RT_MAX_PLAIN_LENGTH
)) {
431 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
438 if (!ssl3_setup_buffers(s
)) {
439 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
);