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-rw-r--r--openssl-1.1.0h/ssl/statem/statem.c860
1 files changed, 860 insertions, 0 deletions
diff --git a/openssl-1.1.0h/ssl/statem/statem.c b/openssl-1.1.0h/ssl/statem/statem.c
new file mode 100644
index 0000000..b91ec0a
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+++ b/openssl-1.1.0h/ssl/statem/statem.c
@@ -0,0 +1,860 @@
+/*
+ * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <openssl/rand.h>
+#include "../ssl_locl.h"
+#include "statem_locl.h"
+
+/*
+ * This file implements the SSL/TLS/DTLS state machines.
+ *
+ * There are two primary state machines:
+ *
+ * 1) Message flow state machine
+ * 2) Handshake state machine
+ *
+ * The Message flow state machine controls the reading and sending of messages
+ * including handling of non-blocking IO events, flushing of the underlying
+ * write BIO, handling unexpected messages, etc. It is itself broken into two
+ * separate sub-state machines which control reading and writing respectively.
+ *
+ * The Handshake state machine keeps track of the current SSL/TLS handshake
+ * state. Transitions of the handshake state are the result of events that
+ * occur within the Message flow state machine.
+ *
+ * Overall it looks like this:
+ *
+ * --------------------------------------------- -------------------
+ * | | | |
+ * | Message flow state machine | | |
+ * | | | |
+ * | -------------------- -------------------- | Transition | Handshake state |
+ * | | MSG_FLOW_READING | | MSG_FLOW_WRITING | | Event | machine |
+ * | | sub-state | | sub-state | |----------->| |
+ * | | machine for | | machine for | | | |
+ * | | reading messages | | writing messages | | | |
+ * | -------------------- -------------------- | | |
+ * | | | |
+ * --------------------------------------------- -------------------
+ *
+ */
+
+/* Sub state machine return values */
+typedef enum {
+ /* Something bad happened or NBIO */
+ SUB_STATE_ERROR,
+ /* Sub state finished go to the next sub state */
+ SUB_STATE_FINISHED,
+ /* Sub state finished and handshake was completed */
+ SUB_STATE_END_HANDSHAKE
+} SUB_STATE_RETURN;
+
+static int state_machine(SSL *s, int server);
+static void init_read_state_machine(SSL *s);
+static SUB_STATE_RETURN read_state_machine(SSL *s);
+static void init_write_state_machine(SSL *s);
+static SUB_STATE_RETURN write_state_machine(SSL *s);
+
+OSSL_HANDSHAKE_STATE SSL_get_state(const SSL *ssl)
+{
+ return ssl->statem.hand_state;
+}
+
+int SSL_in_init(SSL *s)
+{
+ return s->statem.in_init;
+}
+
+int SSL_is_init_finished(SSL *s)
+{
+ return !(s->statem.in_init) && (s->statem.hand_state == TLS_ST_OK);
+}
+
+int SSL_in_before(SSL *s)
+{
+ /*
+ * Historically being "in before" meant before anything had happened. In the
+ * current code though we remain in the "before" state for a while after we
+ * have started the handshake process (e.g. as a server waiting for the
+ * first message to arrive). There "in before" is taken to mean "in before"
+ * and not started any handshake process yet.
+ */
+ return (s->statem.hand_state == TLS_ST_BEFORE)
+ && (s->statem.state == MSG_FLOW_UNINITED);
+}
+
+/*
+ * Clear the state machine state and reset back to MSG_FLOW_UNINITED
+ */
+void ossl_statem_clear(SSL *s)
+{
+ s->statem.state = MSG_FLOW_UNINITED;
+ s->statem.hand_state = TLS_ST_BEFORE;
+ s->statem.in_init = 1;
+ s->statem.no_cert_verify = 0;
+}
+
+/*
+ * Set the state machine up ready for a renegotiation handshake
+ */
+void ossl_statem_set_renegotiate(SSL *s)
+{
+ s->statem.state = MSG_FLOW_RENEGOTIATE;
+ s->statem.in_init = 1;
+}
+
+/*
+ * Put the state machine into an error state. This is a permanent error for
+ * the current connection.
+ */
+void ossl_statem_set_error(SSL *s)
+{
+ s->statem.state = MSG_FLOW_ERROR;
+}
+
+/*
+ * Discover whether the current connection is in the error state.
+ *
+ * Valid return values are:
+ * 1: Yes
+ * 0: No
+ */
+int ossl_statem_in_error(const SSL *s)
+{
+ if (s->statem.state == MSG_FLOW_ERROR)
+ return 1;
+
+ return 0;
+}
+
+void ossl_statem_set_in_init(SSL *s, int init)
+{
+ s->statem.in_init = init;
+}
+
+int ossl_statem_get_in_handshake(SSL *s)
+{
+ return s->statem.in_handshake;
+}
+
+void ossl_statem_set_in_handshake(SSL *s, int inhand)
+{
+ if (inhand)
+ s->statem.in_handshake++;
+ else
+ s->statem.in_handshake--;
+}
+
+void ossl_statem_set_hello_verify_done(SSL *s)
+{
+ s->statem.state = MSG_FLOW_UNINITED;
+ s->statem.in_init = 1;
+ /*
+ * This will get reset (briefly) back to TLS_ST_BEFORE when we enter
+ * state_machine() because |state| is MSG_FLOW_UNINITED, but until then any
+ * calls to SSL_in_before() will return false. Also calls to
+ * SSL_state_string() and SSL_state_string_long() will return something
+ * sensible.
+ */
+ s->statem.hand_state = TLS_ST_SR_CLNT_HELLO;
+}
+
+int ossl_statem_connect(SSL *s)
+{
+ return state_machine(s, 0);
+}
+
+int ossl_statem_accept(SSL *s)
+{
+ return state_machine(s, 1);
+}
+
+typedef void (*info_cb) (const SSL *, int, int);
+
+static info_cb get_callback(SSL *s)
+{
+ if (s->info_callback != NULL)
+ return s->info_callback;
+ else if (s->ctx->info_callback != NULL)
+ return s->ctx->info_callback;
+
+ return NULL;
+}
+
+/*
+ * The main message flow state machine. We start in the MSG_FLOW_UNINITED or
+ * MSG_FLOW_RENEGOTIATE state and finish in MSG_FLOW_FINISHED. Valid states and
+ * transitions are as follows:
+ *
+ * MSG_FLOW_UNINITED MSG_FLOW_RENEGOTIATE
+ * | |
+ * +-----------------------+
+ * v
+ * MSG_FLOW_WRITING <---> MSG_FLOW_READING
+ * |
+ * V
+ * MSG_FLOW_FINISHED
+ * |
+ * V
+ * [SUCCESS]
+ *
+ * We may exit at any point due to an error or NBIO event. If an NBIO event
+ * occurs then we restart at the point we left off when we are recalled.
+ * MSG_FLOW_WRITING and MSG_FLOW_READING have sub-state machines associated with them.
+ *
+ * In addition to the above there is also the MSG_FLOW_ERROR state. We can move
+ * into that state at any point in the event that an irrecoverable error occurs.
+ *
+ * Valid return values are:
+ * 1: Success
+ * <=0: NBIO or error
+ */
+static int state_machine(SSL *s, int server)
+{
+ BUF_MEM *buf = NULL;
+ unsigned long Time = (unsigned long)time(NULL);
+ void (*cb) (const SSL *ssl, int type, int val) = NULL;
+ OSSL_STATEM *st = &s->statem;
+ int ret = -1;
+ int ssret;
+
+ if (st->state == MSG_FLOW_ERROR) {
+ /* Shouldn't have been called if we're already in the error state */
+ return -1;
+ }
+
+ RAND_add(&Time, sizeof(Time), 0);
+ ERR_clear_error();
+ clear_sys_error();
+
+ cb = get_callback(s);
+
+ st->in_handshake++;
+ if (!SSL_in_init(s) || SSL_in_before(s)) {
+ if (!SSL_clear(s))
+ return -1;
+ }
+#ifndef OPENSSL_NO_SCTP
+ if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
+ /*
+ * Notify SCTP BIO socket to enter handshake mode and prevent stream
+ * identifier other than 0.
+ */
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
+ st->in_handshake, NULL);
+ }
+#endif
+
+#ifndef OPENSSL_NO_HEARTBEATS
+ /*
+ * If we're awaiting a HeartbeatResponse, pretend we already got and
+ * don't await it anymore, because Heartbeats don't make sense during
+ * handshakes anyway.
+ */
+ if (s->tlsext_hb_pending) {
+ if (SSL_IS_DTLS(s))
+ dtls1_stop_timer(s);
+ s->tlsext_hb_pending = 0;
+ s->tlsext_hb_seq++;
+ }
+#endif
+
+ /* Initialise state machine */
+
+ if (st->state == MSG_FLOW_RENEGOTIATE) {
+ s->renegotiate = 1;
+ if (!server)
+ s->ctx->stats.sess_connect_renegotiate++;
+ }
+
+ if (st->state == MSG_FLOW_UNINITED || st->state == MSG_FLOW_RENEGOTIATE) {
+ if (st->state == MSG_FLOW_UNINITED) {
+ st->hand_state = TLS_ST_BEFORE;
+ }
+
+ s->server = server;
+ if (cb != NULL)
+ cb(s, SSL_CB_HANDSHAKE_START, 1);
+
+ if (SSL_IS_DTLS(s)) {
+ if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
+ (server || (s->version & 0xff00) != (DTLS1_BAD_VER & 0xff00))) {
+ SSLerr(SSL_F_STATE_MACHINE, ERR_R_INTERNAL_ERROR);
+ goto end;
+ }
+ } else {
+ if ((s->version >> 8) != SSL3_VERSION_MAJOR) {
+ SSLerr(SSL_F_STATE_MACHINE, ERR_R_INTERNAL_ERROR);
+ goto end;
+ }
+ }
+
+ if (!ssl_security(s, SSL_SECOP_VERSION, 0, s->version, NULL)) {
+ SSLerr(SSL_F_STATE_MACHINE, SSL_R_VERSION_TOO_LOW);
+ goto end;
+ }
+
+ if (s->init_buf == NULL) {
+ if ((buf = BUF_MEM_new()) == NULL) {
+ goto end;
+ }
+ if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
+ goto end;
+ }
+ s->init_buf = buf;
+ buf = NULL;
+ }
+
+ if (!ssl3_setup_buffers(s)) {
+ goto end;
+ }
+ s->init_num = 0;
+
+ /*
+ * Should have been reset by tls_process_finished, too.
+ */
+ s->s3->change_cipher_spec = 0;
+
+ /*
+ * Ok, we now need to push on a buffering BIO ...but not with
+ * SCTP
+ */
+#ifndef OPENSSL_NO_SCTP
+ if (!SSL_IS_DTLS(s) || !BIO_dgram_is_sctp(SSL_get_wbio(s)))
+#endif
+ if (!ssl_init_wbio_buffer(s)) {
+ goto end;
+ }
+
+ if (!server || st->state != MSG_FLOW_RENEGOTIATE) {
+ if (!ssl3_init_finished_mac(s)) {
+ ossl_statem_set_error(s);
+ goto end;
+ }
+ }
+
+ if (server) {
+ if (st->state != MSG_FLOW_RENEGOTIATE) {
+ s->ctx->stats.sess_accept++;
+ } else if ((s->options & SSL_OP_NO_RENEGOTIATION)) {
+ /*
+ * Shouldn't happen? The record layer should have prevented this
+ */
+ SSLerr(SSL_F_STATE_MACHINE, ERR_R_INTERNAL_ERROR);
+ ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+ ossl_statem_set_error(s);
+ goto end;
+ } else if (!s->s3->send_connection_binding &&
+ !(s->options &
+ SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
+ /*
+ * Server attempting to renegotiate with client that doesn't
+ * support secure renegotiation.
+ */
+ SSLerr(SSL_F_STATE_MACHINE,
+ SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
+ ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
+ ossl_statem_set_error(s);
+ goto end;
+ } else {
+ /*
+ * st->state == MSG_FLOW_RENEGOTIATE, we will just send a
+ * HelloRequest
+ */
+ s->ctx->stats.sess_accept_renegotiate++;
+ }
+
+ s->s3->tmp.cert_request = 0;
+ } else {
+ s->ctx->stats.sess_connect++;
+
+ /* mark client_random uninitialized */
+ memset(s->s3->client_random, 0, sizeof(s->s3->client_random));
+ s->hit = 0;
+
+ s->s3->tmp.cert_req = 0;
+
+ if (SSL_IS_DTLS(s)) {
+ st->use_timer = 1;
+ }
+ }
+
+ st->state = MSG_FLOW_WRITING;
+ init_write_state_machine(s);
+ st->read_state_first_init = 1;
+ }
+
+ while (st->state != MSG_FLOW_FINISHED) {
+ if (st->state == MSG_FLOW_READING) {
+ ssret = read_state_machine(s);
+ if (ssret == SUB_STATE_FINISHED) {
+ st->state = MSG_FLOW_WRITING;
+ init_write_state_machine(s);
+ } else {
+ /* NBIO or error */
+ goto end;
+ }
+ } else if (st->state == MSG_FLOW_WRITING) {
+ ssret = write_state_machine(s);
+ if (ssret == SUB_STATE_FINISHED) {
+ st->state = MSG_FLOW_READING;
+ init_read_state_machine(s);
+ } else if (ssret == SUB_STATE_END_HANDSHAKE) {
+ st->state = MSG_FLOW_FINISHED;
+ } else {
+ /* NBIO or error */
+ goto end;
+ }
+ } else {
+ /* Error */
+ ossl_statem_set_error(s);
+ goto end;
+ }
+ }
+
+ st->state = MSG_FLOW_UNINITED;
+ ret = 1;
+
+ end:
+ st->in_handshake--;
+
+#ifndef OPENSSL_NO_SCTP
+ if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
+ /*
+ * Notify SCTP BIO socket to leave handshake mode and allow stream
+ * identifier other than 0.
+ */
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
+ st->in_handshake, NULL);
+ }
+#endif
+
+ BUF_MEM_free(buf);
+ if (cb != NULL) {
+ if (server)
+ cb(s, SSL_CB_ACCEPT_EXIT, ret);
+ else
+ cb(s, SSL_CB_CONNECT_EXIT, ret);
+ }
+ return ret;
+}
+
+/*
+ * Initialise the MSG_FLOW_READING sub-state machine
+ */
+static void init_read_state_machine(SSL *s)
+{
+ OSSL_STATEM *st = &s->statem;
+
+ st->read_state = READ_STATE_HEADER;
+}
+
+static int grow_init_buf(SSL *s, size_t size) {
+
+ size_t msg_offset = (char *)s->init_msg - s->init_buf->data;
+
+ if (!BUF_MEM_grow_clean(s->init_buf, (int)size))
+ return 0;
+
+ if (size < msg_offset)
+ return 0;
+
+ s->init_msg = s->init_buf->data + msg_offset;
+
+ return 1;
+}
+
+/*
+ * This function implements the sub-state machine when the message flow is in
+ * MSG_FLOW_READING. The valid sub-states and transitions are:
+ *
+ * READ_STATE_HEADER <--+<-------------+
+ * | | |
+ * v | |
+ * READ_STATE_BODY -----+-->READ_STATE_POST_PROCESS
+ * | |
+ * +----------------------------+
+ * v
+ * [SUB_STATE_FINISHED]
+ *
+ * READ_STATE_HEADER has the responsibility for reading in the message header
+ * and transitioning the state of the handshake state machine.
+ *
+ * READ_STATE_BODY reads in the rest of the message and then subsequently
+ * processes it.
+ *
+ * READ_STATE_POST_PROCESS is an optional step that may occur if some post
+ * processing activity performed on the message may block.
+ *
+ * Any of the above states could result in an NBIO event occurring in which case
+ * control returns to the calling application. When this function is recalled we
+ * will resume in the same state where we left off.
+ */
+static SUB_STATE_RETURN read_state_machine(SSL *s)
+{
+ OSSL_STATEM *st = &s->statem;
+ int ret, mt;
+ unsigned long len = 0;
+ int (*transition) (SSL *s, int mt);
+ PACKET pkt;
+ MSG_PROCESS_RETURN(*process_message) (SSL *s, PACKET *pkt);
+ WORK_STATE(*post_process_message) (SSL *s, WORK_STATE wst);
+ unsigned long (*max_message_size) (SSL *s);
+ void (*cb) (const SSL *ssl, int type, int val) = NULL;
+
+ cb = get_callback(s);
+
+ if (s->server) {
+ transition = ossl_statem_server_read_transition;
+ process_message = ossl_statem_server_process_message;
+ max_message_size = ossl_statem_server_max_message_size;
+ post_process_message = ossl_statem_server_post_process_message;
+ } else {
+ transition = ossl_statem_client_read_transition;
+ process_message = ossl_statem_client_process_message;
+ max_message_size = ossl_statem_client_max_message_size;
+ post_process_message = ossl_statem_client_post_process_message;
+ }
+
+ if (st->read_state_first_init) {
+ s->first_packet = 1;
+ st->read_state_first_init = 0;
+ }
+
+ while (1) {
+ switch (st->read_state) {
+ case READ_STATE_HEADER:
+ /* Get the state the peer wants to move to */
+ if (SSL_IS_DTLS(s)) {
+ /*
+ * In DTLS we get the whole message in one go - header and body
+ */
+ ret = dtls_get_message(s, &mt, &len);
+ } else {
+ ret = tls_get_message_header(s, &mt);
+ }
+
+ if (ret == 0) {
+ /* Could be non-blocking IO */
+ return SUB_STATE_ERROR;
+ }
+
+ if (cb != NULL) {
+ /* Notify callback of an impending state change */
+ if (s->server)
+ cb(s, SSL_CB_ACCEPT_LOOP, 1);
+ else
+ cb(s, SSL_CB_CONNECT_LOOP, 1);
+ }
+ /*
+ * Validate that we are allowed to move to the new state and move
+ * to that state if so
+ */
+ if (!transition(s, mt)) {
+ ossl_statem_set_error(s);
+ return SUB_STATE_ERROR;
+ }
+
+ if (s->s3->tmp.message_size > max_message_size(s)) {
+ ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
+ SSLerr(SSL_F_READ_STATE_MACHINE, SSL_R_EXCESSIVE_MESSAGE_SIZE);
+ return SUB_STATE_ERROR;
+ }
+
+ /* dtls_get_message already did this */
+ if (!SSL_IS_DTLS(s)
+ && s->s3->tmp.message_size > 0
+ && !grow_init_buf(s, s->s3->tmp.message_size
+ + SSL3_HM_HEADER_LENGTH)) {
+ ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+ SSLerr(SSL_F_READ_STATE_MACHINE, ERR_R_BUF_LIB);
+ return SUB_STATE_ERROR;
+ }
+
+ st->read_state = READ_STATE_BODY;
+ /* Fall through */
+
+ case READ_STATE_BODY:
+ if (!SSL_IS_DTLS(s)) {
+ /* We already got this above for DTLS */
+ ret = tls_get_message_body(s, &len);
+ if (ret == 0) {
+ /* Could be non-blocking IO */
+ return SUB_STATE_ERROR;
+ }
+ }
+
+ s->first_packet = 0;
+ if (!PACKET_buf_init(&pkt, s->init_msg, len)) {
+ ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+ SSLerr(SSL_F_READ_STATE_MACHINE, ERR_R_INTERNAL_ERROR);
+ return SUB_STATE_ERROR;
+ }
+ ret = process_message(s, &pkt);
+
+ /* Discard the packet data */
+ s->init_num = 0;
+
+ switch (ret) {
+ case MSG_PROCESS_ERROR:
+ return SUB_STATE_ERROR;
+
+ case MSG_PROCESS_FINISHED_READING:
+ if (SSL_IS_DTLS(s)) {
+ dtls1_stop_timer(s);
+ }
+ return SUB_STATE_FINISHED;
+
+ case MSG_PROCESS_CONTINUE_PROCESSING:
+ st->read_state = READ_STATE_POST_PROCESS;
+ st->read_state_work = WORK_MORE_A;
+ break;
+
+ default:
+ st->read_state = READ_STATE_HEADER;
+ break;
+ }
+ break;
+
+ case READ_STATE_POST_PROCESS:
+ st->read_state_work = post_process_message(s, st->read_state_work);
+ switch (st->read_state_work) {
+ default:
+ return SUB_STATE_ERROR;
+
+ case WORK_FINISHED_CONTINUE:
+ st->read_state = READ_STATE_HEADER;
+ break;
+
+ case WORK_FINISHED_STOP:
+ if (SSL_IS_DTLS(s)) {
+ dtls1_stop_timer(s);
+ }
+ return SUB_STATE_FINISHED;
+ }
+ break;
+
+ default:
+ /* Shouldn't happen */
+ ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+ SSLerr(SSL_F_READ_STATE_MACHINE, ERR_R_INTERNAL_ERROR);
+ ossl_statem_set_error(s);
+ return SUB_STATE_ERROR;
+ }
+ }
+}
+
+/*
+ * Send a previously constructed message to the peer.
+ */
+static int statem_do_write(SSL *s)
+{
+ OSSL_STATEM *st = &s->statem;
+
+ if (st->hand_state == TLS_ST_CW_CHANGE
+ || st->hand_state == TLS_ST_SW_CHANGE) {
+ if (SSL_IS_DTLS(s))
+ return dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
+ else
+ return ssl3_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
+ } else {
+ return ssl_do_write(s);
+ }
+}
+
+/*
+ * Initialise the MSG_FLOW_WRITING sub-state machine
+ */
+static void init_write_state_machine(SSL *s)
+{
+ OSSL_STATEM *st = &s->statem;
+
+ st->write_state = WRITE_STATE_TRANSITION;
+}
+
+/*
+ * This function implements the sub-state machine when the message flow is in
+ * MSG_FLOW_WRITING. The valid sub-states and transitions are:
+ *
+ * +-> WRITE_STATE_TRANSITION ------> [SUB_STATE_FINISHED]
+ * | |
+ * | v
+ * | WRITE_STATE_PRE_WORK -----> [SUB_STATE_END_HANDSHAKE]
+ * | |
+ * | v
+ * | WRITE_STATE_SEND
+ * | |
+ * | v
+ * | WRITE_STATE_POST_WORK
+ * | |
+ * +-------------+
+ *
+ * WRITE_STATE_TRANSITION transitions the state of the handshake state machine
+
+ * WRITE_STATE_PRE_WORK performs any work necessary to prepare the later
+ * sending of the message. This could result in an NBIO event occurring in
+ * which case control returns to the calling application. When this function
+ * is recalled we will resume in the same state where we left off.
+ *
+ * WRITE_STATE_SEND sends the message and performs any work to be done after
+ * sending.
+ *
+ * WRITE_STATE_POST_WORK performs any work necessary after the sending of the
+ * message has been completed. As for WRITE_STATE_PRE_WORK this could also
+ * result in an NBIO event.
+ */
+static SUB_STATE_RETURN write_state_machine(SSL *s)
+{
+ OSSL_STATEM *st = &s->statem;
+ int ret;
+ WRITE_TRAN(*transition) (SSL *s);
+ WORK_STATE(*pre_work) (SSL *s, WORK_STATE wst);
+ WORK_STATE(*post_work) (SSL *s, WORK_STATE wst);
+ int (*construct_message) (SSL *s);
+ void (*cb) (const SSL *ssl, int type, int val) = NULL;
+
+ cb = get_callback(s);
+
+ if (s->server) {
+ transition = ossl_statem_server_write_transition;
+ pre_work = ossl_statem_server_pre_work;
+ post_work = ossl_statem_server_post_work;
+ construct_message = ossl_statem_server_construct_message;
+ } else {
+ transition = ossl_statem_client_write_transition;
+ pre_work = ossl_statem_client_pre_work;
+ post_work = ossl_statem_client_post_work;
+ construct_message = ossl_statem_client_construct_message;
+ }
+
+ while (1) {
+ switch (st->write_state) {
+ case WRITE_STATE_TRANSITION:
+ if (cb != NULL) {
+ /* Notify callback of an impending state change */
+ if (s->server)
+ cb(s, SSL_CB_ACCEPT_LOOP, 1);
+ else
+ cb(s, SSL_CB_CONNECT_LOOP, 1);
+ }
+ switch (transition(s)) {
+ case WRITE_TRAN_CONTINUE:
+ st->write_state = WRITE_STATE_PRE_WORK;
+ st->write_state_work = WORK_MORE_A;
+ break;
+
+ case WRITE_TRAN_FINISHED:
+ return SUB_STATE_FINISHED;
+ break;
+
+ default:
+ return SUB_STATE_ERROR;
+ }
+ break;
+
+ case WRITE_STATE_PRE_WORK:
+ switch (st->write_state_work = pre_work(s, st->write_state_work)) {
+ default:
+ return SUB_STATE_ERROR;
+
+ case WORK_FINISHED_CONTINUE:
+ st->write_state = WRITE_STATE_SEND;
+ break;
+
+ case WORK_FINISHED_STOP:
+ return SUB_STATE_END_HANDSHAKE;
+ }
+ if (construct_message(s) == 0)
+ return SUB_STATE_ERROR;
+
+ /* Fall through */
+
+ case WRITE_STATE_SEND:
+ if (SSL_IS_DTLS(s) && st->use_timer) {
+ dtls1_start_timer(s);
+ }
+ ret = statem_do_write(s);
+ if (ret <= 0) {
+ return SUB_STATE_ERROR;
+ }
+ st->write_state = WRITE_STATE_POST_WORK;
+ st->write_state_work = WORK_MORE_A;
+ /* Fall through */
+
+ case WRITE_STATE_POST_WORK:
+ switch (st->write_state_work = post_work(s, st->write_state_work)) {
+ default:
+ return SUB_STATE_ERROR;
+
+ case WORK_FINISHED_CONTINUE:
+ st->write_state = WRITE_STATE_TRANSITION;
+ break;
+
+ case WORK_FINISHED_STOP:
+ return SUB_STATE_END_HANDSHAKE;
+ }
+ break;
+
+ default:
+ return SUB_STATE_ERROR;
+ }
+ }
+}
+
+/*
+ * Flush the write BIO
+ */
+int statem_flush(SSL *s)
+{
+ s->rwstate = SSL_WRITING;
+ if (BIO_flush(s->wbio) <= 0) {
+ return 0;
+ }
+ s->rwstate = SSL_NOTHING;
+
+ return 1;
+}
+
+/*
+ * Called by the record layer to determine whether application data is
+ * allowed to be sent in the current handshake state or not.
+ *
+ * Return values are:
+ * 1: Yes (application data allowed)
+ * 0: No (application data not allowed)
+ */
+int ossl_statem_app_data_allowed(SSL *s)
+{
+ OSSL_STATEM *st = &s->statem;
+
+ if (st->state == MSG_FLOW_UNINITED || st->state == MSG_FLOW_RENEGOTIATE)
+ return 0;
+
+ if (!s->s3->in_read_app_data || (s->s3->total_renegotiations == 0))
+ return 0;
+
+ if (s->server) {
+ /*
+ * If we're a server and we haven't got as far as writing our
+ * ServerHello yet then we allow app data
+ */
+ if (st->hand_state == TLS_ST_BEFORE
+ || st->hand_state == TLS_ST_SR_CLNT_HELLO)
+ return 1;
+ } else {
+ /*
+ * If we're a client and we haven't read the ServerHello yet then we
+ * allow app data
+ */
+ if (st->hand_state == TLS_ST_CW_CLNT_HELLO)
+ return 1;
+ }
+
+ return 0;
+}