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
);
442 if (!ssl3_setup_buffers(s
)) {
443 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
449 * Should have been reset by tls_process_finished, too.
451 s
->s3
.change_cipher_spec
= 0;
454 * Ok, we now need to push on a buffering BIO ...but not with
457 #ifndef OPENSSL_NO_SCTP
458 if (!SSL_CONNECTION_IS_DTLS(s
) || !BIO_dgram_is_sctp(SSL_get_wbio(ssl
)))
460 if (!ssl_init_wbio_buffer(s
)) {
461 SSLfatal(s
, SSL_AD_NO_ALERT
, ERR_R_INTERNAL_ERROR
);
465 if ((SSL_in_before(ssl
))
467 if (!tls_setup_handshake(s
)) {
468 /* SSLfatal() already called */
472 if (SSL_IS_FIRST_HANDSHAKE(s
))
473 st
->read_state_first_init
= 1;
476 st
->state
= MSG_FLOW_WRITING
;
477 init_write_state_machine(s
);
480 while (st
->state
!= MSG_FLOW_FINISHED
) {
481 if (st
->state
== MSG_FLOW_READING
) {
482 ssret
= read_state_machine(s
);
483 if (ssret
== SUB_STATE_FINISHED
) {
484 st
->state
= MSG_FLOW_WRITING
;
485 init_write_state_machine(s
);
490 } else if (st
->state
== MSG_FLOW_WRITING
) {
491 ssret
= write_state_machine(s
);
492 if (ssret
== SUB_STATE_FINISHED
) {
493 st
->state
= MSG_FLOW_READING
;
494 init_read_state_machine(s
);
495 } else if (ssret
== SUB_STATE_END_HANDSHAKE
) {
496 st
->state
= MSG_FLOW_FINISHED
;
504 ERR_raise(ERR_LIB_SSL
, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED
);
514 #ifndef OPENSSL_NO_SCTP
515 if (SSL_CONNECTION_IS_DTLS(s
) && BIO_dgram_is_sctp(SSL_get_wbio(ssl
))) {
517 * Notify SCTP BIO socket to leave handshake mode and allow stream
518 * identifier other than 0.
520 BIO_ctrl(SSL_get_wbio(ssl
), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE
,
521 st
->in_handshake
, NULL
);
528 cb(ssl
, SSL_CB_ACCEPT_EXIT
, ret
);
530 cb(ssl
, SSL_CB_CONNECT_EXIT
, ret
);
536 * Initialise the MSG_FLOW_READING sub-state machine
538 static void init_read_state_machine(SSL_CONNECTION
*s
)
540 OSSL_STATEM
*st
= &s
->statem
;
542 st
->read_state
= READ_STATE_HEADER
;
545 static int grow_init_buf(SSL_CONNECTION
*s
, size_t size
) {
547 size_t msg_offset
= (char *)s
->init_msg
- s
->init_buf
->data
;
549 if (!BUF_MEM_grow_clean(s
->init_buf
, (int)size
))
552 if (size
< msg_offset
)
555 s
->init_msg
= s
->init_buf
->data
+ msg_offset
;
561 * This function implements the sub-state machine when the message flow is in
562 * MSG_FLOW_READING. The valid sub-states and transitions are:
564 * READ_STATE_HEADER <--+<-------------+
567 * READ_STATE_BODY -----+-->READ_STATE_POST_PROCESS
569 * +----------------------------+
571 * [SUB_STATE_FINISHED]
573 * READ_STATE_HEADER has the responsibility for reading in the message header
574 * and transitioning the state of the handshake state machine.
576 * READ_STATE_BODY reads in the rest of the message and then subsequently
579 * READ_STATE_POST_PROCESS is an optional step that may occur if some post
580 * processing activity performed on the message may block.
582 * Any of the above states could result in an NBIO event occurring in which case
583 * control returns to the calling application. When this function is recalled we
584 * will resume in the same state where we left off.
586 static SUB_STATE_RETURN
read_state_machine(SSL_CONNECTION
*s
)
588 OSSL_STATEM
*st
= &s
->statem
;
591 int (*transition
) (SSL_CONNECTION
*s
, int mt
);
593 MSG_PROCESS_RETURN(*process_message
) (SSL_CONNECTION
*s
, PACKET
*pkt
);
594 WORK_STATE(*post_process_message
) (SSL_CONNECTION
*s
, WORK_STATE wst
);
595 size_t (*max_message_size
) (SSL_CONNECTION
*s
);
596 void (*cb
) (const SSL
*ssl
, int type
, int val
) = NULL
;
597 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
599 cb
= get_callback(s
);
602 transition
= ossl_statem_server_read_transition
;
603 process_message
= ossl_statem_server_process_message
;
604 max_message_size
= ossl_statem_server_max_message_size
;
605 post_process_message
= ossl_statem_server_post_process_message
;
607 transition
= ossl_statem_client_read_transition
;
608 process_message
= ossl_statem_client_process_message
;
609 max_message_size
= ossl_statem_client_max_message_size
;
610 post_process_message
= ossl_statem_client_post_process_message
;
613 if (st
->read_state_first_init
) {
615 st
->read_state_first_init
= 0;
619 switch (st
->read_state
) {
620 case READ_STATE_HEADER
:
621 /* Get the state the peer wants to move to */
622 if (SSL_CONNECTION_IS_DTLS(s
)) {
624 * In DTLS we get the whole message in one go - header and body
626 ret
= dtls_get_message(s
, &mt
);
628 ret
= tls_get_message_header(s
, &mt
);
632 /* Could be non-blocking IO */
633 return SUB_STATE_ERROR
;
637 /* Notify callback of an impending state change */
639 cb(ssl
, SSL_CB_ACCEPT_LOOP
, 1);
641 cb(ssl
, SSL_CB_CONNECT_LOOP
, 1);
644 * Validate that we are allowed to move to the new state and move
645 * to that state if so
647 if (!transition(s
, mt
))
648 return SUB_STATE_ERROR
;
650 if (s
->s3
.tmp
.message_size
> max_message_size(s
)) {
651 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
,
652 SSL_R_EXCESSIVE_MESSAGE_SIZE
);
653 return SUB_STATE_ERROR
;
656 /* dtls_get_message already did this */
657 if (!SSL_CONNECTION_IS_DTLS(s
)
658 && s
->s3
.tmp
.message_size
> 0
659 && !grow_init_buf(s
, s
->s3
.tmp
.message_size
660 + SSL3_HM_HEADER_LENGTH
)) {
661 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_BUF_LIB
);
662 return SUB_STATE_ERROR
;
665 st
->read_state
= READ_STATE_BODY
;
668 case READ_STATE_BODY
:
669 if (SSL_CONNECTION_IS_DTLS(s
)) {
671 * Actually we already have the body, but we give DTLS the
672 * opportunity to do any further processing.
674 ret
= dtls_get_message_body(s
, &len
);
676 ret
= tls_get_message_body(s
, &len
);
679 /* Could be non-blocking IO */
680 return SUB_STATE_ERROR
;
684 if (!PACKET_buf_init(&pkt
, s
->init_msg
, len
)) {
685 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
686 return SUB_STATE_ERROR
;
688 ret
= process_message(s
, &pkt
);
690 /* Discard the packet data */
694 case MSG_PROCESS_ERROR
:
696 return SUB_STATE_ERROR
;
698 case MSG_PROCESS_FINISHED_READING
:
699 if (SSL_CONNECTION_IS_DTLS(s
)) {
702 return SUB_STATE_FINISHED
;
704 case MSG_PROCESS_CONTINUE_PROCESSING
:
705 st
->read_state
= READ_STATE_POST_PROCESS
;
706 st
->read_state_work
= WORK_MORE_A
;
710 st
->read_state
= READ_STATE_HEADER
;
715 case READ_STATE_POST_PROCESS
:
716 st
->read_state_work
= post_process_message(s
, st
->read_state_work
);
717 switch (st
->read_state_work
) {
724 return SUB_STATE_ERROR
;
726 case WORK_FINISHED_CONTINUE
:
727 st
->read_state
= READ_STATE_HEADER
;
730 case WORK_FINISHED_STOP
:
731 if (SSL_CONNECTION_IS_DTLS(s
)) {
734 return SUB_STATE_FINISHED
;
739 /* Shouldn't happen */
740 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
741 return SUB_STATE_ERROR
;
747 * Send a previously constructed message to the peer.
749 static int statem_do_write(SSL_CONNECTION
*s
)
751 OSSL_STATEM
*st
= &s
->statem
;
753 if (st
->hand_state
== TLS_ST_CW_CHANGE
754 || st
->hand_state
== TLS_ST_SW_CHANGE
) {
755 if (SSL_CONNECTION_IS_DTLS(s
))
756 return dtls1_do_write(s
, SSL3_RT_CHANGE_CIPHER_SPEC
);
758 return ssl3_do_write(s
, SSL3_RT_CHANGE_CIPHER_SPEC
);
760 return ssl_do_write(s
);
765 * Initialise the MSG_FLOW_WRITING sub-state machine
767 static void init_write_state_machine(SSL_CONNECTION
*s
)
769 OSSL_STATEM
*st
= &s
->statem
;
771 st
->write_state
= WRITE_STATE_TRANSITION
;
775 * This function implements the sub-state machine when the message flow is in
776 * MSG_FLOW_WRITING. The valid sub-states and transitions are:
778 * +-> WRITE_STATE_TRANSITION ------> [SUB_STATE_FINISHED]
781 * | WRITE_STATE_PRE_WORK -----> [SUB_STATE_END_HANDSHAKE]
787 * | WRITE_STATE_POST_WORK
791 * WRITE_STATE_TRANSITION transitions the state of the handshake state machine
793 * WRITE_STATE_PRE_WORK performs any work necessary to prepare the later
794 * sending of the message. This could result in an NBIO event occurring in
795 * which case control returns to the calling application. When this function
796 * is recalled we will resume in the same state where we left off.
798 * WRITE_STATE_SEND sends the message and performs any work to be done after
801 * WRITE_STATE_POST_WORK performs any work necessary after the sending of the
802 * message has been completed. As for WRITE_STATE_PRE_WORK this could also
803 * result in an NBIO event.
805 static SUB_STATE_RETURN
write_state_machine(SSL_CONNECTION
*s
)
807 OSSL_STATEM
*st
= &s
->statem
;
809 WRITE_TRAN(*transition
) (SSL_CONNECTION
*s
);
810 WORK_STATE(*pre_work
) (SSL_CONNECTION
*s
, WORK_STATE wst
);
811 WORK_STATE(*post_work
) (SSL_CONNECTION
*s
, WORK_STATE wst
);
812 int (*get_construct_message_f
) (SSL_CONNECTION
*s
,
813 CON_FUNC_RETURN (**confunc
) (SSL_CONNECTION
*s
,
816 void (*cb
) (const SSL
*ssl
, int type
, int val
) = NULL
;
817 CON_FUNC_RETURN (*confunc
) (SSL_CONNECTION
*s
, WPACKET
*pkt
);
820 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
822 cb
= get_callback(s
);
825 transition
= ossl_statem_server_write_transition
;
826 pre_work
= ossl_statem_server_pre_work
;
827 post_work
= ossl_statem_server_post_work
;
828 get_construct_message_f
= ossl_statem_server_construct_message
;
830 transition
= ossl_statem_client_write_transition
;
831 pre_work
= ossl_statem_client_pre_work
;
832 post_work
= ossl_statem_client_post_work
;
833 get_construct_message_f
= ossl_statem_client_construct_message
;
837 switch (st
->write_state
) {
838 case WRITE_STATE_TRANSITION
:
840 /* Notify callback of an impending state change */
842 cb(ssl
, SSL_CB_ACCEPT_LOOP
, 1);
844 cb(ssl
, SSL_CB_CONNECT_LOOP
, 1);
846 switch (transition(s
)) {
847 case WRITE_TRAN_CONTINUE
:
848 st
->write_state
= WRITE_STATE_PRE_WORK
;
849 st
->write_state_work
= WORK_MORE_A
;
852 case WRITE_TRAN_FINISHED
:
853 return SUB_STATE_FINISHED
;
856 case WRITE_TRAN_ERROR
:
858 return SUB_STATE_ERROR
;
862 case WRITE_STATE_PRE_WORK
:
863 switch (st
->write_state_work
= pre_work(s
, st
->write_state_work
)) {
870 return SUB_STATE_ERROR
;
872 case WORK_FINISHED_CONTINUE
:
873 st
->write_state
= WRITE_STATE_SEND
;
876 case WORK_FINISHED_STOP
:
877 return SUB_STATE_END_HANDSHAKE
;
879 if (!get_construct_message_f(s
, &confunc
, &mt
)) {
880 /* SSLfatal() already called */
881 return SUB_STATE_ERROR
;
883 if (mt
== SSL3_MT_DUMMY
) {
884 /* Skip construction and sending. This isn't a "real" state */
885 st
->write_state
= WRITE_STATE_POST_WORK
;
886 st
->write_state_work
= WORK_MORE_A
;
889 if (!WPACKET_init(&pkt
, s
->init_buf
)
890 || !ssl_set_handshake_header(s
, &pkt
, mt
)) {
891 WPACKET_cleanup(&pkt
);
892 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
893 return SUB_STATE_ERROR
;
895 if (confunc
!= NULL
) {
896 CON_FUNC_RETURN tmpret
;
898 tmpret
= confunc(s
, &pkt
);
899 if (tmpret
== CON_FUNC_ERROR
) {
900 WPACKET_cleanup(&pkt
);
902 return SUB_STATE_ERROR
;
903 } else if (tmpret
== CON_FUNC_DONT_SEND
) {
905 * The construction function decided not to construct the
906 * message after all and continue. Skip sending.
908 WPACKET_cleanup(&pkt
);
909 st
->write_state
= WRITE_STATE_POST_WORK
;
910 st
->write_state_work
= WORK_MORE_A
;
914 if (!ssl_close_construct_packet(s
, &pkt
, mt
)
915 || !WPACKET_finish(&pkt
)) {
916 WPACKET_cleanup(&pkt
);
917 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
918 return SUB_STATE_ERROR
;
923 case WRITE_STATE_SEND
:
924 if (SSL_CONNECTION_IS_DTLS(s
) && st
->use_timer
) {
925 dtls1_start_timer(s
);
927 ret
= statem_do_write(s
);
929 return SUB_STATE_ERROR
;
931 st
->write_state
= WRITE_STATE_POST_WORK
;
932 st
->write_state_work
= WORK_MORE_A
;
935 case WRITE_STATE_POST_WORK
:
936 switch (st
->write_state_work
= post_work(s
, st
->write_state_work
)) {
943 return SUB_STATE_ERROR
;
945 case WORK_FINISHED_CONTINUE
:
946 st
->write_state
= WRITE_STATE_TRANSITION
;
949 case WORK_FINISHED_STOP
:
950 return SUB_STATE_END_HANDSHAKE
;
955 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
956 return SUB_STATE_ERROR
;
962 * Flush the write BIO
964 int statem_flush(SSL_CONNECTION
*s
)
966 s
->rwstate
= SSL_WRITING
;
967 if (BIO_flush(s
->wbio
) <= 0) {
970 s
->rwstate
= SSL_NOTHING
;
976 * Called by the record layer to determine whether application data is
977 * allowed to be received in the current handshake state or not.
980 * 1: Yes (application data allowed)
981 * 0: No (application data not allowed)
983 int ossl_statem_app_data_allowed(SSL_CONNECTION
*s
)
985 OSSL_STATEM
*st
= &s
->statem
;
987 if (st
->state
== MSG_FLOW_UNINITED
)
990 if (!s
->s3
.in_read_app_data
|| (s
->s3
.total_renegotiations
== 0))
995 * If we're a server and we haven't got as far as writing our
996 * ServerHello yet then we allow app data
998 if (st
->hand_state
== TLS_ST_BEFORE
999 || st
->hand_state
== TLS_ST_SR_CLNT_HELLO
)
1003 * If we're a client and we haven't read the ServerHello yet then we
1006 if (st
->hand_state
== TLS_ST_CW_CLNT_HELLO
)
1014 * This function returns 1 if TLS exporter is ready to export keying
1015 * material, or 0 if otherwise.
1017 int ossl_statem_export_allowed(SSL_CONNECTION
*s
)
1019 return s
->s3
.previous_server_finished_len
!= 0
1020 && s
->statem
.hand_state
!= TLS_ST_SW_FINISHED
;
1024 * Return 1 if early TLS exporter is ready to export keying material,
1025 * or 0 if otherwise.
1027 int ossl_statem_export_early_allowed(SSL_CONNECTION
*s
)
1030 * The early exporter secret is only present on the server if we
1031 * have accepted early_data. It is present on the client as long
1032 * as we have sent early_data.
1034 return s
->ext
.early_data
== SSL_EARLY_DATA_ACCEPTED
1035 || (!s
->server
&& s
->ext
.early_data
!= SSL_EARLY_DATA_NOT_SENT
);