Reorganise state machine files
Pull out the state machine into a separate sub directory. Also moved some
functions which were nothing to do with the state machine but were in state
machine files. Pulled all the SSL_METHOD definitions into one place...most
of those files had very little left in them any more.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
diff --git a/ssl/statem/statem.c b/ssl/statem/statem.c
new file mode 100644
index 0000000..7e4f524
--- /dev/null
+++ b/ssl/statem/statem.c
@@ -0,0 +1,2241 @@
+/* ssl/statem/statem.c */
+/*
+ * Written by Matt Caswell for the OpenSSL project.
+ */
+/* ====================================================================
+ * Copyright (c) 1998-2015 The OpenSSL Project. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ * software must display the following acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+#include <openssl/rand.h>
+#include "../ssl_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 */
+enum SUB_STATE_RETURN {
+ /* 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
+};
+
+static int state_machine(SSL *s, int server);
+static void init_read_state_machine(SSL *s);
+static enum SUB_STATE_RETURN read_state_machine(SSL *s);
+static void init_write_state_machine(SSL *s);
+static enum SUB_STATE_RETURN write_state_machine(SSL *s);
+static inline int cert_req_allowed(SSL *s);
+static inline int key_exchange_skip_allowed(SSL *s);
+static int client_read_transition(SSL *s, int mt);
+static enum WRITE_TRAN client_write_transition(SSL *s);
+static enum WORK_STATE client_pre_work(SSL *s, enum WORK_STATE wst);
+static enum WORK_STATE client_post_work(SSL *s, enum WORK_STATE wst);
+static int client_construct_message(SSL *s);
+static unsigned long client_max_message_size(SSL *s);
+static enum MSG_PROCESS_RETURN client_process_message(SSL *s, PACKET *pkt);
+static enum WORK_STATE client_post_process_message(SSL *s, enum WORK_STATE wst);
+static int server_read_transition(SSL *s, int mt);
+static inline int send_server_key_exchange(SSL *s);
+static inline int send_certificate_request(SSL *s);
+static enum WRITE_TRAN server_write_transition(SSL *s);
+static enum WORK_STATE server_pre_work(SSL *s, enum WORK_STATE wst);
+static enum WORK_STATE server_post_work(SSL *s, enum WORK_STATE wst);
+static int server_construct_message(SSL *s);
+static unsigned long server_max_message_size(SSL *s);
+static enum MSG_PROCESS_RETURN server_process_message(SSL *s, PACKET *pkt);
+static enum WORK_STATE server_post_process_message(SSL *s, enum WORK_STATE wst);
+
+
+enum HANDSHAKE_STATE SSL_state(const SSL *ssl)
+{
+ return ssl->statem.hand_state;
+}
+
+void SSL_set_state(SSL *ssl, enum HANDSHAKE_STATE state)
+{
+ /*
+ * This function seems like a really bad idea. Should we remove it
+ * completely?
+ */
+ ssl->statem.hand_state = 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 statem_clear(SSL *s)
+{
+ s->statem.state = MSG_FLOW_UNINITED;
+ s->statem.hand_state = TLS_ST_BEFORE;
+ s->statem.in_init = 1;
+}
+
+/*
+ * Set the state machine up ready for a renegotiation handshake
+ */
+void 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 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 statem_in_error(const SSL *s)
+{
+ if (s->statem.state == MSG_FLOW_ERROR)
+ return 1;
+
+ return 0;
+}
+
+void statem_set_in_init(SSL *s, int init)
+{
+ s->statem.in_init = init;
+}
+
+int statem_connect(SSL *s) {
+ return state_machine(s, 0);
+}
+
+int statem_accept(SSL *s)
+{
+ return state_machine(s, 1);
+}
+
+/*
+ * 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;
+ 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();
+
+ if (s->info_callback != NULL)
+ cb = s->info_callback;
+ else if (s->ctx->info_callback != NULL)
+ cb = s->ctx->info_callback;
+
+ s->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)) {
+ /*
+ * Notify SCTP BIO socket to enter handshake mode and prevent stream
+ * identifier other than 0. Will be ignored if no SCTP is used.
+ */
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
+ s->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
+ && s->version != TLS_ANY_VERSION) {
+ SSLerr(SSL_F_STATE_MACHINE, ERR_R_INTERNAL_ERROR);
+ goto end;
+ }
+ }
+
+ if (!SSL_IS_DTLS(s)) {
+ if (s->version != TLS_ANY_VERSION &&
+ !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;
+
+ if (!server || st->state != MSG_FLOW_RENEGOTIATE) {
+ /*
+ * 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, server ? 1 : 0)) {
+ goto end;
+ }
+
+ ssl3_init_finished_mac(s);
+ }
+
+ if (server) {
+ if (st->state != MSG_FLOW_RENEGOTIATE) {
+ s->ctx->stats.sess_accept++;
+ } 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);
+ statem_set_error(s);
+ goto end;
+ } else {
+ /*
+ * s->state == SSL_ST_RENEGOTIATE, we will just send a
+ * HelloRequest
+ */
+ s->ctx->stats.sess_accept_renegotiate++;
+ }
+ } 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_request = 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 */
+ statem_set_error(s);
+ goto end;
+ }
+ }
+
+ st->state = MSG_FLOW_UNINITED;
+ ret = 1;
+
+ end:
+ s->in_handshake--;
+
+#ifndef OPENSSL_NO_SCTP
+ if (SSL_IS_DTLS(s)) {
+ /*
+ * Notify SCTP BIO socket to leave handshake mode and allow stream
+ * identifier other than 0. Will be ignored if no SCTP is used.
+ */
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
+ s->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)
+{
+ STATEM *st = &s->statem;
+
+ st->read_state = READ_STATE_HEADER;
+}
+
+/*
+ * 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 occuring 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 enum SUB_STATE_RETURN read_state_machine(SSL *s) {
+ STATEM *st = &s->statem;
+ int ret, mt;
+ unsigned long len;
+ int (*transition)(SSL *s, int mt);
+ PACKET pkt;
+ enum MSG_PROCESS_RETURN (*process_message)(SSL *s, PACKET *pkt);
+ enum WORK_STATE (*post_process_message)(SSL *s, enum WORK_STATE wst);
+ unsigned long (*max_message_size)(SSL *s);
+ void (*cb) (const SSL *ssl, int type, int val) = NULL;
+
+ if (s->info_callback != NULL)
+ cb = s->info_callback;
+ else if (s->ctx->info_callback != NULL)
+ cb = s->ctx->info_callback;
+
+ if(s->server) {
+ transition = server_read_transition;
+ process_message = server_process_message;
+ max_message_size = server_max_message_size;
+ post_process_message = server_post_process_message;
+ } else {
+ transition = client_read_transition;
+ process_message = client_process_message;
+ max_message_size = client_max_message_size;
+ post_process_message = 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:
+ s->init_num = 0;
+ /* 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)) {
+ ssl3_send_alert(s, SSL3_AL_FATAL, SSL3_AD_UNEXPECTED_MESSAGE);
+ SSLerr(SSL_F_READ_STATE_MACHINE, SSL_R_UNEXPECTED_MESSAGE);
+ 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;
+ }
+
+ 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);
+ if (ret == MSG_PROCESS_ERROR) {
+ return SUB_STATE_ERROR;
+ }
+
+ if (ret == MSG_PROCESS_FINISHED_READING) {
+ if (SSL_IS_DTLS(s)) {
+ dtls1_stop_timer(s);
+ }
+ return SUB_STATE_FINISHED;
+ }
+
+ if (ret == MSG_PROCESS_CONTINUE_PROCESSING) {
+ st->read_state = READ_STATE_POST_PROCESS;
+ st->read_state_work = WORK_MORE_A;
+ } else {
+ st->read_state = READ_STATE_HEADER;
+ }
+ 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);
+ statem_set_error(s);
+ return SUB_STATE_ERROR;
+ }
+ }
+}
+
+/*
+ * Send a previously constructed message to the peer.
+ */
+static int statem_do_write(SSL *s)
+{
+ 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)
+{
+ 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 occuring 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 enum SUB_STATE_RETURN write_state_machine(SSL *s)
+{
+ STATEM *st = &s->statem;
+ int ret;
+ enum WRITE_TRAN (*transition)(SSL *s);
+ enum WORK_STATE (*pre_work)(SSL *s, enum WORK_STATE wst);
+ enum WORK_STATE (*post_work)(SSL *s, enum WORK_STATE wst);
+ int (*construct_message)(SSL *s);
+ void (*cb) (const SSL *ssl, int type, int val) = NULL;
+
+ if (s->info_callback != NULL)
+ cb = s->info_callback;
+ else if (s->ctx->info_callback != NULL)
+ cb = s->ctx->info_callback;
+
+ if(s->server) {
+ transition = server_write_transition;
+ pre_work = server_pre_work;
+ post_work = server_post_work;
+ construct_message = server_construct_message;
+ } else {
+ transition = client_write_transition;
+ pre_work = client_pre_work;
+ post_work = client_post_work;
+ construct_message = 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
+ */
+static 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 statem_app_data_allowed(SSL *s)
+{
+ 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;
+}
+
+
+#ifndef OPENSSL_NO_SCTP
+/*
+ * Set flag used by SCTP to determine whether we are in the read sock state
+ */
+void statem_set_sctp_read_sock(SSL *s, int read_sock)
+{
+ s->statem.in_sctp_read_sock = read_sock;
+}
+
+/*
+ * Called by the record layer to determine whether we are in the read sock
+ * state or not.
+ *
+ * Return values are:
+ * 1: Yes (we are in the read sock state)
+ * 0: No (we are not in the read sock state)
+ */
+int statem_in_sctp_read_sock(SSL *s)
+{
+ return s->statem.in_sctp_read_sock;
+}
+#endif
+
+/*
+ * Is a CertificateRequest message allowed at the moment or not?
+ *
+ * Return values are:
+ * 1: Yes
+ * 0: No
+ */
+static inline int cert_req_allowed(SSL *s)
+{
+ /* TLS does not like anon-DH with client cert */
+ if (s->version > SSL3_VERSION
+ && (s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL))
+ return 0;
+
+ return 1;
+}
+
+/*
+ * Are we allowed to skip the ServerKeyExchange message?
+ *
+ * Return values are:
+ * 1: Yes
+ * 0: No
+ */
+static inline int key_exchange_skip_allowed(SSL *s)
+{
+ long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
+
+ /*
+ * Can't skip server key exchange if this is an ephemeral
+ * ciphersuite.
+ */
+ if (alg_k & (SSL_kDHE | SSL_kECDHE)) {
+ return 0;
+ }
+
+ return 1;
+}
+
+/*
+ * client_read_transition() encapsulates the logic for the allowed handshake
+ * state transitions when the client is reading messages from the server. The
+ * message type that the server has sent is provided in |mt|. The current state
+ * is in |s->statem.hand_state|.
+ *
+ * Return values are:
+ * 1: Success (transition allowed)
+ * 0: Error (transition not allowed)
+ */
+static int client_read_transition(SSL *s, int mt)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_CW_CLNT_HELLO:
+ if (mt == SSL3_MT_SERVER_HELLO) {
+ st->hand_state = TLS_ST_CR_SRVR_HELLO;
+ return 1;
+ }
+
+ if (SSL_IS_DTLS(s)) {
+ if (mt == DTLS1_MT_HELLO_VERIFY_REQUEST) {
+ st->hand_state = DTLS_ST_CR_HELLO_VERIFY_REQUEST;
+ return 1;
+ }
+ }
+ break;
+
+ case TLS_ST_CR_SRVR_HELLO:
+ if (s->hit) {
+ if (s->tlsext_ticket_expected) {
+ if (mt == SSL3_MT_NEWSESSION_TICKET) {
+ st->hand_state = TLS_ST_CR_SESSION_TICKET;
+ return 1;
+ }
+ } else if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+ st->hand_state = TLS_ST_CR_CHANGE;
+ return 1;
+ }
+ } else {
+ if (SSL_IS_DTLS(s) && mt == DTLS1_MT_HELLO_VERIFY_REQUEST) {
+ st->hand_state = DTLS_ST_CR_HELLO_VERIFY_REQUEST;
+ return 1;
+ } else if (!(s->s3->tmp.new_cipher->algorithm_auth
+ & (SSL_aNULL | SSL_aSRP | SSL_aPSK))) {
+ if (mt == SSL3_MT_CERTIFICATE) {
+ st->hand_state = TLS_ST_CR_CERT;
+ return 1;
+ }
+ } else {
+ if (mt == SSL3_MT_SERVER_KEY_EXCHANGE) {
+ st->hand_state = TLS_ST_CR_KEY_EXCH;
+ return 1;
+ } else if (key_exchange_skip_allowed(s)) {
+ if (mt == SSL3_MT_CERTIFICATE_REQUEST
+ && cert_req_allowed(s)) {
+ st->hand_state = TLS_ST_CR_CERT_REQ;
+ return 1;
+ } else if (mt == SSL3_MT_SERVER_DONE) {
+ st->hand_state = TLS_ST_CR_SRVR_DONE;
+ return 1;
+ }
+ }
+ }
+ }
+ break;
+
+ case TLS_ST_CR_CERT:
+ if (s->tlsext_status_expected) {
+ if (mt == SSL3_MT_CERTIFICATE_STATUS) {
+ st->hand_state = TLS_ST_CR_CERT_STATUS;
+ return 1;
+ }
+ } else {
+ if (mt == SSL3_MT_SERVER_KEY_EXCHANGE) {
+ st->hand_state = TLS_ST_CR_KEY_EXCH;
+ return 1;
+ } else if (key_exchange_skip_allowed(s)) {
+ if (mt == SSL3_MT_CERTIFICATE_REQUEST && cert_req_allowed(s)) {
+ st->hand_state = TLS_ST_CR_CERT_REQ;
+ return 1;
+ } else if (mt == SSL3_MT_SERVER_DONE) {
+ st->hand_state = TLS_ST_CR_SRVR_DONE;
+ return 1;
+ }
+ }
+ }
+ break;
+
+ case TLS_ST_CR_CERT_STATUS:
+ if (mt == SSL3_MT_SERVER_KEY_EXCHANGE) {
+ st->hand_state = TLS_ST_CR_KEY_EXCH;
+ return 1;
+ } else if (key_exchange_skip_allowed(s)) {
+ if (mt == SSL3_MT_CERTIFICATE_REQUEST && cert_req_allowed(s)) {
+ st->hand_state = TLS_ST_CR_CERT_REQ;
+ return 1;
+ } else if (mt == SSL3_MT_SERVER_DONE) {
+ st->hand_state = TLS_ST_CR_SRVR_DONE;
+ return 1;
+ }
+ }
+ break;
+
+ case TLS_ST_CR_KEY_EXCH:
+ if (mt == SSL3_MT_CERTIFICATE_REQUEST && cert_req_allowed(s)) {
+ st->hand_state = TLS_ST_CR_CERT_REQ;
+ return 1;
+ } else if (mt == SSL3_MT_SERVER_DONE) {
+ st->hand_state = TLS_ST_CR_SRVR_DONE;
+ return 1;
+ }
+ break;
+
+ case TLS_ST_CR_CERT_REQ:
+ if (mt == SSL3_MT_SERVER_DONE) {
+ st->hand_state = TLS_ST_CR_SRVR_DONE;
+ return 1;
+ }
+ break;
+
+ case TLS_ST_CW_FINISHED:
+ if (mt == SSL3_MT_NEWSESSION_TICKET && s->tlsext_ticket_expected) {
+ st->hand_state = TLS_ST_CR_SESSION_TICKET;
+ return 1;
+ } else if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+ st->hand_state = TLS_ST_CR_CHANGE;
+ return 1;
+ }
+ break;
+
+ case TLS_ST_CR_SESSION_TICKET:
+ if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+ st->hand_state = TLS_ST_CR_CHANGE;
+ return 1;
+ }
+ break;
+
+ case TLS_ST_CR_CHANGE:
+ if (mt == SSL3_MT_FINISHED) {
+ st->hand_state = TLS_ST_CR_FINISHED;
+ return 1;
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ /* No valid transition found */
+ return 0;
+}
+
+/*
+ * client_write_transition() works out what handshake state to move to next
+ * when the client is writing messages to be sent to the server.
+ */
+static enum WRITE_TRAN client_write_transition(SSL *s)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_OK:
+ /* Renegotiation - fall through */
+ case TLS_ST_BEFORE:
+ st->hand_state = TLS_ST_CW_CLNT_HELLO;
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_CW_CLNT_HELLO:
+ /*
+ * No transition at the end of writing because we don't know what
+ * we will be sent
+ */
+ return WRITE_TRAN_FINISHED;
+
+ case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
+ st->hand_state = TLS_ST_CW_CLNT_HELLO;
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_CR_SRVR_DONE:
+ if (s->s3->tmp.cert_req)
+ st->hand_state = TLS_ST_CW_CERT;
+ else
+ st->hand_state = TLS_ST_CW_KEY_EXCH;
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_CW_CERT:
+ st->hand_state = TLS_ST_CW_KEY_EXCH;
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_CW_KEY_EXCH:
+ /*
+ * For TLS, cert_req is set to 2, so a cert chain of nothing is
+ * sent, but no verify packet is sent
+ */
+ /*
+ * XXX: For now, we do not support client authentication in ECDH
+ * cipher suites with ECDH (rather than ECDSA) certificates. We
+ * need to skip the certificate verify message when client's
+ * ECDH public key is sent inside the client certificate.
+ */
+ if (s->s3->tmp.cert_req == 1) {
+ st->hand_state = TLS_ST_CW_CERT_VRFY;
+ } else {
+ st->hand_state = TLS_ST_CW_CHANGE;
+ }
+ if (s->s3->flags & TLS1_FLAGS_SKIP_CERT_VERIFY) {
+ st->hand_state = TLS_ST_CW_CHANGE;
+ }
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_CW_CERT_VRFY:
+ st->hand_state = TLS_ST_CW_CHANGE;
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_CW_CHANGE:
+#if defined(OPENSSL_NO_NEXTPROTONEG)
+ st->hand_state = TLS_ST_CW_FINISHED;
+#else
+ if (!SSL_IS_DTLS(s) && s->s3->next_proto_neg_seen)
+ st->hand_state = TLS_ST_CW_NEXT_PROTO;
+ else
+ st->hand_state = TLS_ST_CW_FINISHED;
+#endif
+ return WRITE_TRAN_CONTINUE;
+
+#if !defined(OPENSSL_NO_NEXTPROTONEG)
+ case TLS_ST_CW_NEXT_PROTO:
+ st->hand_state = TLS_ST_CW_FINISHED;
+ return WRITE_TRAN_CONTINUE;
+#endif
+
+ case TLS_ST_CW_FINISHED:
+ if (s->hit) {
+ st->hand_state = TLS_ST_OK;
+ statem_set_in_init(s, 0);
+ return WRITE_TRAN_CONTINUE;
+ } else {
+ return WRITE_TRAN_FINISHED;
+ }
+
+ case TLS_ST_CR_FINISHED:
+ if (s->hit) {
+ st->hand_state = TLS_ST_CW_CHANGE;
+ return WRITE_TRAN_CONTINUE;
+ } else {
+ st->hand_state = TLS_ST_OK;
+ statem_set_in_init(s, 0);
+ return WRITE_TRAN_CONTINUE;
+ }
+
+ default:
+ /* Shouldn't happen */
+ return WRITE_TRAN_ERROR;
+ }
+}
+
+/*
+ * Perform any pre work that needs to be done prior to sending a message from
+ * the client to the server.
+ */
+static enum WORK_STATE client_pre_work(SSL *s, enum WORK_STATE wst)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_CW_CLNT_HELLO:
+ s->shutdown = 0;
+ if (SSL_IS_DTLS(s)) {
+ /* every DTLS ClientHello resets Finished MAC */
+ ssl3_init_finished_mac(s);
+ }
+ break;
+
+ case TLS_ST_CW_CERT:
+ return tls_prepare_client_certificate(s, wst);
+
+ case TLS_ST_CW_CHANGE:
+ if (SSL_IS_DTLS(s)) {
+ if (s->hit) {
+ /*
+ * We're into the last flight so we don't retransmit these
+ * messages unless we need to.
+ */
+ st->use_timer = 0;
+ }
+#ifndef OPENSSL_NO_SCTP
+ if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
+ return dtls_wait_for_dry(s);
+#endif
+ }
+ return WORK_FINISHED_CONTINUE;
+
+ case TLS_ST_OK:
+ return tls_finish_handshake(s, wst);
+
+ default:
+ /* No pre work to be done */
+ break;
+ }
+
+ return WORK_FINISHED_CONTINUE;
+}
+
+/*
+ * Perform any work that needs to be done after sending a message from the
+ * client to the server.
+ */
+static enum WORK_STATE client_post_work(SSL *s, enum WORK_STATE wst)
+{
+ STATEM *st = &s->statem;
+
+ s->init_num = 0;
+
+ switch(st->hand_state) {
+ case TLS_ST_CW_CLNT_HELLO:
+ if (SSL_IS_DTLS(s) && s->d1->cookie_len > 0 && statem_flush(s) != 1)
+ return WORK_MORE_A;
+#ifndef OPENSSL_NO_SCTP
+ /* Disable buffering for SCTP */
+ if (!SSL_IS_DTLS(s) || !BIO_dgram_is_sctp(SSL_get_wbio(s))) {
+#endif
+ /*
+ * turn on buffering for the next lot of output
+ */
+ if (s->bbio != s->wbio)
+ s->wbio = BIO_push(s->bbio, s->wbio);
+#ifndef OPENSSL_NO_SCTP
+ }
+#endif
+ if (SSL_IS_DTLS(s)) {
+ /* Treat the next message as the first packet */
+ s->first_packet = 1;
+ }
+ break;
+
+ case TLS_ST_CW_KEY_EXCH:
+ if (tls_client_key_exchange_post_work(s) == 0)
+ return WORK_ERROR;
+ break;
+
+ case TLS_ST_CW_CHANGE:
+ s->session->cipher = s->s3->tmp.new_cipher;
+#ifdef OPENSSL_NO_COMP
+ s->session->compress_meth = 0;
+#else
+ if (s->s3->tmp.new_compression == NULL)
+ s->session->compress_meth = 0;
+ else
+ s->session->compress_meth = s->s3->tmp.new_compression->id;
+#endif
+ if (!s->method->ssl3_enc->setup_key_block(s))
+ return WORK_ERROR;
+
+ if (!s->method->ssl3_enc->change_cipher_state(s,
+ SSL3_CHANGE_CIPHER_CLIENT_WRITE))
+ return WORK_ERROR;
+
+ if (SSL_IS_DTLS(s)) {
+#ifndef OPENSSL_NO_SCTP
+ if (s->hit) {
+ /*
+ * Change to new shared key of SCTP-Auth, will be ignored if
+ * no SCTP used.
+ */
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
+ 0, NULL);
+ }
+#endif
+
+ dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
+ }
+ break;
+
+ case TLS_ST_CW_FINISHED:
+#ifndef OPENSSL_NO_SCTP
+ if (wst == WORK_MORE_A && SSL_IS_DTLS(s) && s->hit == 0) {
+ /*
+ * Change to new shared key of SCTP-Auth, will be ignored if
+ * no SCTP used.
+ */
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
+ 0, NULL);
+ }
+#endif
+ if (statem_flush(s) != 1)
+ return WORK_MORE_B;
+
+ if (s->hit && tls_finish_handshake(s, WORK_MORE_A) != 1)
+ return WORK_ERROR;
+ break;
+
+ default:
+ /* No post work to be done */
+ break;
+ }
+
+ return WORK_FINISHED_CONTINUE;
+}
+
+/*
+ * Construct a message to be sent from the client to the server.
+ *
+ * Valid return values are:
+ * 1: Success
+ * 0: Error
+ */
+static int client_construct_message(SSL *s)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_CW_CLNT_HELLO:
+ return tls_construct_client_hello(s);
+
+ case TLS_ST_CW_CERT:
+ return tls_construct_client_certificate(s);
+
+ case TLS_ST_CW_KEY_EXCH:
+ return tls_construct_client_key_exchange(s);
+
+ case TLS_ST_CW_CERT_VRFY:
+ return tls_construct_client_verify(s);
+
+ case TLS_ST_CW_CHANGE:
+ if (SSL_IS_DTLS(s))
+ return dtls_construct_change_cipher_spec(s);
+ else
+ return tls_construct_change_cipher_spec(s);
+
+#if !defined(OPENSSL_NO_NEXTPROTONEG)
+ case TLS_ST_CW_NEXT_PROTO:
+ return tls_construct_next_proto(s);
+#endif
+ case TLS_ST_CW_FINISHED:
+ return tls_construct_finished(s,
+ s->method->
+ ssl3_enc->client_finished_label,
+ s->method->
+ ssl3_enc->client_finished_label_len);
+
+ default:
+ /* Shouldn't happen */
+ break;
+ }
+
+ return 0;
+}
+
+/* The spec allows for a longer length than this, but we limit it */
+#define HELLO_VERIFY_REQUEST_MAX_LENGTH 258
+#define SERVER_HELLO_MAX_LENGTH 20000
+#define SERVER_KEY_EXCH_MAX_LENGTH 102400
+#define SERVER_HELLO_DONE_MAX_LENGTH 0
+#define CCS_MAX_LENGTH 1
+/* Max should actually be 36 but we are generous */
+#define FINISHED_MAX_LENGTH 64
+
+/*
+ * Returns the maximum allowed length for the current message that we are
+ * reading. Excludes the message header.
+ */
+static unsigned long client_max_message_size(SSL *s)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_CR_SRVR_HELLO:
+ return SERVER_HELLO_MAX_LENGTH;
+
+ case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
+ return HELLO_VERIFY_REQUEST_MAX_LENGTH;
+
+ case TLS_ST_CR_CERT:
+ return s->max_cert_list;
+
+ case TLS_ST_CR_CERT_STATUS:
+ return SSL3_RT_MAX_PLAIN_LENGTH;
+
+ case TLS_ST_CR_KEY_EXCH:
+ return SERVER_KEY_EXCH_MAX_LENGTH;
+
+ case TLS_ST_CR_CERT_REQ:
+ return SSL3_RT_MAX_PLAIN_LENGTH;
+
+ case TLS_ST_CR_SRVR_DONE:
+ return SERVER_HELLO_DONE_MAX_LENGTH;
+
+ case TLS_ST_CR_CHANGE:
+ return CCS_MAX_LENGTH;
+
+ case TLS_ST_CR_SESSION_TICKET:
+ return SSL3_RT_MAX_PLAIN_LENGTH;
+
+ case TLS_ST_CR_FINISHED:
+ return FINISHED_MAX_LENGTH;
+
+ default:
+ /* Shouldn't happen */
+ break;
+ }
+
+ return 0;
+}
+
+/*
+ * Process a message that the client has been received from the server.
+ */
+static enum MSG_PROCESS_RETURN client_process_message(SSL *s, PACKET *pkt)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_CR_SRVR_HELLO:
+ return tls_process_server_hello(s, pkt);
+
+ case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
+ return dtls_process_hello_verify(s, pkt);
+
+ case TLS_ST_CR_CERT:
+ return tls_process_server_certificate(s, pkt);
+
+ case TLS_ST_CR_CERT_STATUS:
+ return tls_process_cert_status(s, pkt);
+
+ case TLS_ST_CR_KEY_EXCH:
+ return tls_process_key_exchange(s, pkt);
+
+ case TLS_ST_CR_CERT_REQ:
+ return tls_process_certificate_request(s, pkt);
+
+ case TLS_ST_CR_SRVR_DONE:
+ return tls_process_server_done(s, pkt);
+
+ case TLS_ST_CR_CHANGE:
+ return tls_process_change_cipher_spec(s, pkt);
+
+ case TLS_ST_CR_SESSION_TICKET:
+ return tls_process_new_session_ticket(s, pkt);
+
+ case TLS_ST_CR_FINISHED:
+ return tls_process_finished(s, pkt);
+
+ default:
+ /* Shouldn't happen */
+ break;
+ }
+
+ return MSG_PROCESS_ERROR;
+}
+
+/*
+ * Perform any further processing required following the receipt of a message
+ * from the server
+ */
+static enum WORK_STATE client_post_process_message(SSL *s, enum WORK_STATE wst)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+#ifndef OPENSSL_NO_SCTP
+ case TLS_ST_CR_SRVR_DONE:
+ /* We only get here if we are using SCTP and we are renegotiating */
+ if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
+ s->s3->in_read_app_data = 2;
+ s->rwstate = SSL_READING;
+ BIO_clear_retry_flags(SSL_get_rbio(s));
+ BIO_set_retry_read(SSL_get_rbio(s));
+ statem_set_sctp_read_sock(s, 1);
+ return WORK_MORE_A;
+ }
+ statem_set_sctp_read_sock(s, 0);
+ return WORK_FINISHED_STOP;
+#endif
+
+ case TLS_ST_CR_FINISHED:
+ if (!s->hit)
+ return tls_finish_handshake(s, wst);
+ else
+ return WORK_FINISHED_STOP;
+ default:
+ break;
+ }
+
+ /* Shouldn't happen */
+ return WORK_ERROR;
+}
+
+
+/*
+ * server_read_transition() encapsulates the logic for the allowed handshake
+ * state transitions when the server is reading messages from the client. The
+ * message type that the client has sent is provided in |mt|. The current state
+ * is in |s->statem.hand_state|.
+ *
+ * Valid return values are:
+ * 1: Success (transition allowed)
+ * 0: Error (transition not allowed)
+ */
+static int server_read_transition(SSL *s, int mt)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_BEFORE:
+ case DTLS_ST_SW_HELLO_VERIFY_REQUEST:
+ if (mt == SSL3_MT_CLIENT_HELLO) {
+ st->hand_state = TLS_ST_SR_CLNT_HELLO;
+ return 1;
+ }
+ break;
+
+ case TLS_ST_SW_SRVR_DONE:
+ /*
+ * If we get a CKE message after a ServerDone then either
+ * 1) We didn't request a Certificate
+ * OR
+ * 2) If we did request one then
+ * a) We allow no Certificate to be returned
+ * AND
+ * b) We are running SSL3 (in TLS1.0+ the client must return a 0
+ * list if we requested a certificate)
+ */
+ if (mt == SSL3_MT_CLIENT_KEY_EXCHANGE
+ && (!s->s3->tmp.cert_request
+ || (!((s->verify_mode & SSL_VERIFY_PEER) &&
+ (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))
+ && (s->version == SSL3_VERSION)))) {
+ st->hand_state = TLS_ST_SR_KEY_EXCH;
+ return 1;
+ } else if (s->s3->tmp.cert_request) {
+ if (mt == SSL3_MT_CERTIFICATE) {
+ st->hand_state = TLS_ST_SR_CERT;
+ return 1;
+ }
+ }
+ break;
+
+ case TLS_ST_SR_CERT:
+ if (mt == SSL3_MT_CLIENT_KEY_EXCHANGE) {
+ st->hand_state = TLS_ST_SR_KEY_EXCH;
+ return 1;
+ }
+ break;
+
+ case TLS_ST_SR_KEY_EXCH:
+ /*
+ * We should only process a CertificateVerify message if we have
+ * received a Certificate from the client. If so then |s->session->peer|
+ * will be non NULL. In some instances a CertificateVerify message is
+ * not required even if the peer has sent a Certificate (e.g. such as in
+ * the case of static DH). In that case |s->no_cert_verify| should be
+ * set.
+ */
+ if (s->session->peer == NULL || s->no_cert_verify) {
+ if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+ /*
+ * For the ECDH ciphersuites when the client sends its ECDH
+ * pub key in a certificate, the CertificateVerify message is
+ * not sent. Also for GOST ciphersuites when the client uses
+ * its key from the certificate for key exchange.
+ */
+ st->hand_state = TLS_ST_SR_CHANGE;
+ return 1;
+ }
+ } else {
+ if (mt == SSL3_MT_CERTIFICATE_VERIFY) {
+ st->hand_state = TLS_ST_SR_CERT_VRFY;
+ return 1;
+ }
+ }
+ break;
+
+ case TLS_ST_SR_CERT_VRFY:
+ if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+ st->hand_state = TLS_ST_SR_CHANGE;
+ return 1;
+ }
+ break;
+
+ case TLS_ST_SR_CHANGE:
+#ifndef OPENSSL_NO_NEXTPROTONEG
+ if (s->s3->next_proto_neg_seen) {
+ if (mt == SSL3_MT_NEXT_PROTO) {
+ st->hand_state = TLS_ST_SR_NEXT_PROTO;
+ return 1;
+ }
+ } else {
+#endif
+ if (mt == SSL3_MT_FINISHED) {
+ st->hand_state = TLS_ST_SR_FINISHED;
+ return 1;
+ }
+#ifndef OPENSSL_NO_NEXTPROTONEG
+ }
+#endif
+ break;
+
+#ifndef OPENSSL_NO_NEXTPROTONEG
+ case TLS_ST_SR_NEXT_PROTO:
+ if (mt == SSL3_MT_FINISHED) {
+ st->hand_state = TLS_ST_SR_FINISHED;
+ return 1;
+ }
+ break;
+#endif
+
+ case TLS_ST_SW_FINISHED:
+ if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+ st->hand_state = TLS_ST_SR_CHANGE;
+ return 1;
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ /* No valid transition found */
+ return 0;
+}
+
+/*
+ * Should we send a ServerKeyExchange message?
+ *
+ * Valid return values are:
+ * 1: Yes
+ * 0: No
+ */
+static inline int send_server_key_exchange(SSL *s)
+{
+ unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
+
+ /*
+ * only send a ServerKeyExchange if DH, fortezza or RSA but we have a
+ * sign only certificate PSK: may send PSK identity hints For
+ * ECC ciphersuites, we send a serverKeyExchange message only if
+ * the cipher suite is either ECDH-anon or ECDHE. In other cases,
+ * the server certificate contains the server's public key for
+ * key exchange.
+ */
+ if ( (alg_k & SSL_kDHE)
+ || (alg_k & SSL_kECDHE)
+ || ((alg_k & SSL_kRSA)
+ && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
+ || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
+ && EVP_PKEY_size(s->cert->pkeys
+ [SSL_PKEY_RSA_ENC].privatekey) *
+ 8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
+ )
+ )
+ )
+ /*
+ * PSK: send ServerKeyExchange if PSK identity hint if
+ * provided
+ */
+#ifndef OPENSSL_NO_PSK
+ /* Only send SKE if we have identity hint for plain PSK */
+ || ((alg_k & (SSL_kPSK | SSL_kRSAPSK))
+ && s->cert->psk_identity_hint)
+ /* For other PSK always send SKE */
+ || (alg_k & (SSL_PSK & (SSL_kDHEPSK | SSL_kECDHEPSK)))
+#endif
+#ifndef OPENSSL_NO_SRP
+ /* SRP: send ServerKeyExchange */
+ || (alg_k & SSL_kSRP)
+#endif
+ ) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * Should we send a CertificateRequest message?
+ *
+ * Valid return values are:
+ * 1: Yes
+ * 0: No
+ */
+static inline int send_certificate_request(SSL *s)
+{
+ if (
+ /* don't request cert unless asked for it: */
+ s->verify_mode & SSL_VERIFY_PEER
+ /*
+ * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
+ * during re-negotiation:
+ */
+ && ((s->session->peer == NULL) ||
+ !(s->verify_mode & SSL_VERIFY_CLIENT_ONCE))
+ /*
+ * never request cert in anonymous ciphersuites (see
+ * section "Certificate request" in SSL 3 drafts and in
+ * RFC 2246):
+ */
+ && (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
+ /*
+ * ... except when the application insists on
+ * verification (against the specs, but s3_clnt.c accepts
+ * this for SSL 3)
+ */
+ || (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))
+ /* don't request certificate for SRP auth */
+ && !(s->s3->tmp.new_cipher->algorithm_auth & SSL_aSRP)
+ /*
+ * With normal PSK Certificates and Certificate Requests
+ * are omitted
+ */
+ && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_PSK)) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * server_write_transition() works out what handshake state to move to next
+ * when the server is writing messages to be sent to the client.
+ */
+static enum WRITE_TRAN server_write_transition(SSL *s)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_BEFORE:
+ /* Just go straight to trying to read from the client */;
+ return WRITE_TRAN_FINISHED;
+
+ case TLS_ST_OK:
+ /* We must be trying to renegotiate */
+ st->hand_state = TLS_ST_SW_HELLO_REQ;
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_SW_HELLO_REQ:
+ st->hand_state = TLS_ST_OK;
+ statem_set_in_init(s, 0);
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_SR_CLNT_HELLO:
+ if (SSL_IS_DTLS(s) && !s->d1->cookie_verified
+ && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
+ st->hand_state = DTLS_ST_SW_HELLO_VERIFY_REQUEST;
+ else
+ st->hand_state = TLS_ST_SW_SRVR_HELLO;
+ return WRITE_TRAN_CONTINUE;
+
+ case DTLS_ST_SW_HELLO_VERIFY_REQUEST:
+ return WRITE_TRAN_FINISHED;
+
+ case TLS_ST_SW_SRVR_HELLO:
+ if (s->hit) {
+ if (s->tlsext_ticket_expected)
+ st->hand_state = TLS_ST_SW_SESSION_TICKET;
+ else
+ st->hand_state = TLS_ST_SW_CHANGE;
+ } else {
+ /* Check if it is anon DH or anon ECDH, */
+ /* normal PSK or SRP */
+ if (!(s->s3->tmp.new_cipher->algorithm_auth &
+ (SSL_aNULL | SSL_aSRP | SSL_aPSK))) {
+ st->hand_state = TLS_ST_SW_CERT;
+ } else if (send_server_key_exchange(s)) {
+ st->hand_state = TLS_ST_SW_KEY_EXCH;
+ } else if (send_certificate_request(s)) {
+ st->hand_state = TLS_ST_SW_CERT_REQ;
+ } else {
+ st->hand_state = TLS_ST_SW_SRVR_DONE;
+ }
+ }
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_SW_CERT:
+ if (s->tlsext_status_expected) {
+ st->hand_state = TLS_ST_SW_CERT_STATUS;
+ return WRITE_TRAN_CONTINUE;
+ }
+ /* Fall through */
+
+ case TLS_ST_SW_CERT_STATUS:
+ if (send_server_key_exchange(s)) {
+ st->hand_state = TLS_ST_SW_KEY_EXCH;
+ return WRITE_TRAN_CONTINUE;
+ }
+ /* Fall through */
+
+ case TLS_ST_SW_KEY_EXCH:
+ if (send_certificate_request(s)) {
+ st->hand_state = TLS_ST_SW_CERT_REQ;
+ return WRITE_TRAN_CONTINUE;
+ }
+ /* Fall through */
+
+ case TLS_ST_SW_CERT_REQ:
+ st->hand_state = TLS_ST_SW_SRVR_DONE;
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_SW_SRVR_DONE:
+ return WRITE_TRAN_FINISHED;
+
+ case TLS_ST_SR_FINISHED:
+ if (s->hit) {
+ st->hand_state = TLS_ST_OK;
+ statem_set_in_init(s, 0);
+ return WRITE_TRAN_CONTINUE;
+ } else if (s->tlsext_ticket_expected) {
+ st->hand_state = TLS_ST_SW_SESSION_TICKET;
+ } else {
+ st->hand_state = TLS_ST_SW_CHANGE;
+ }
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_SW_SESSION_TICKET:
+ st->hand_state = TLS_ST_SW_CHANGE;
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_SW_CHANGE:
+ st->hand_state = TLS_ST_SW_FINISHED;
+ return WRITE_TRAN_CONTINUE;
+
+ case TLS_ST_SW_FINISHED:
+ if (s->hit) {
+ return WRITE_TRAN_FINISHED;
+ }
+ st->hand_state = TLS_ST_OK;
+ statem_set_in_init(s, 0);
+ return WRITE_TRAN_CONTINUE;
+
+ default:
+ /* Shouldn't happen */
+ return WRITE_TRAN_ERROR;
+ }
+}
+
+/*
+ * Perform any pre work that needs to be done prior to sending a message from
+ * the server to the client.
+ */
+static enum WORK_STATE server_pre_work(SSL *s, enum WORK_STATE wst)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_SW_HELLO_REQ:
+ s->shutdown = 0;
+ if (SSL_IS_DTLS(s))
+ dtls1_clear_record_buffer(s);
+ break;
+
+ case DTLS_ST_SW_HELLO_VERIFY_REQUEST:
+ s->shutdown = 0;
+ if (SSL_IS_DTLS(s)) {
+ dtls1_clear_record_buffer(s);
+ /* We don't buffer this message so don't use the timer */
+ st->use_timer = 0;
+ }
+ break;
+
+ case TLS_ST_SW_SRVR_HELLO:
+ if (SSL_IS_DTLS(s)) {
+ /*
+ * Messages we write from now on should be bufferred and
+ * retransmitted if necessary, so we need to use the timer now
+ */
+ st->use_timer = 1;
+ }
+ break;
+
+ case TLS_ST_SW_SRVR_DONE:
+#ifndef OPENSSL_NO_SCTP
+ if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s)))
+ return dtls_wait_for_dry(s);
+#endif
+ return WORK_FINISHED_CONTINUE;
+
+ case TLS_ST_SW_SESSION_TICKET:
+ if (SSL_IS_DTLS(s)) {
+ /*
+ * We're into the last flight. We don't retransmit the last flight
+ * unless we need to, so we don't use the timer
+ */
+ st->use_timer = 0;
+ }
+ break;
+
+ case TLS_ST_SW_CHANGE:
+ s->session->cipher = s->s3->tmp.new_cipher;
+ if (!s->method->ssl3_enc->setup_key_block(s)) {
+ statem_set_error(s);
+ return WORK_ERROR;
+ }
+ if (SSL_IS_DTLS(s)) {
+ /*
+ * We're into the last flight. We don't retransmit the last flight
+ * unless we need to, so we don't use the timer. This might have
+ * already been set to 0 if we sent a NewSessionTicket message,
+ * but we'll set it again here in case we didn't.
+ */
+ st->use_timer = 0;
+ }
+ return WORK_FINISHED_CONTINUE;
+
+ case TLS_ST_OK:
+ return tls_finish_handshake(s, wst);
+
+ default:
+ /* No pre work to be done */
+ break;
+ }
+
+ return WORK_FINISHED_CONTINUE;
+}
+
+/*
+ * Perform any work that needs to be done after sending a message from the
+ * server to the client.
+ */
+static enum WORK_STATE server_post_work(SSL *s, enum WORK_STATE wst)
+{
+ STATEM *st = &s->statem;
+
+ s->init_num = 0;
+
+ switch(st->hand_state) {
+ case TLS_ST_SW_HELLO_REQ:
+ if (statem_flush(s) != 1)
+ return WORK_MORE_A;
+ ssl3_init_finished_mac(s);
+ break;
+
+ case DTLS_ST_SW_HELLO_VERIFY_REQUEST:
+ if (statem_flush(s) != 1)
+ return WORK_MORE_A;
+ /* HelloVerifyRequest resets Finished MAC */
+ if (s->version != DTLS1_BAD_VER)
+ ssl3_init_finished_mac(s);
+ /*
+ * The next message should be another ClientHello which we need to
+ * treat like it was the first packet
+ */
+ s->first_packet = 1;
+ break;
+
+ case TLS_ST_SW_SRVR_HELLO:
+#ifndef OPENSSL_NO_SCTP
+ if (SSL_IS_DTLS(s) && s->hit) {
+ unsigned char sctpauthkey[64];
+ char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
+
+ /*
+ * Add new shared key for SCTP-Auth, will be ignored if no
+ * SCTP used.
+ */
+ snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
+ DTLS1_SCTP_AUTH_LABEL);
+
+ if (SSL_export_keying_material(s, sctpauthkey,
+ sizeof(sctpauthkey), labelbuffer,
+ sizeof(labelbuffer), NULL, 0, 0) <= 0) {
+ statem_set_error(s);
+ return WORK_ERROR;
+ }
+
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
+ sizeof(sctpauthkey), sctpauthkey);
+ }
+#endif
+ break;
+
+ case TLS_ST_SW_CHANGE:
+#ifndef OPENSSL_NO_SCTP
+ if (SSL_IS_DTLS(s) && !s->hit) {
+ /*
+ * Change to new shared key of SCTP-Auth, will be ignored if
+ * no SCTP used.
+ */
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
+ 0, NULL);
+ }
+#endif
+ if (!s->method->ssl3_enc->change_cipher_state(s,
+ SSL3_CHANGE_CIPHER_SERVER_WRITE)) {
+ statem_set_error(s);
+ return WORK_ERROR;
+ }
+
+ if (SSL_IS_DTLS(s))
+ dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
+ break;
+
+ case TLS_ST_SW_SRVR_DONE:
+ if (statem_flush(s) != 1)
+ return WORK_MORE_A;
+ break;
+
+ case TLS_ST_SW_FINISHED:
+ if (statem_flush(s) != 1)
+ return WORK_MORE_A;
+#ifndef OPENSSL_NO_SCTP
+ if (SSL_IS_DTLS(s) && s->hit) {
+ /*
+ * Change to new shared key of SCTP-Auth, will be ignored if
+ * no SCTP used.
+ */
+ BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
+ 0, NULL);
+ }
+#endif
+ break;
+
+ default:
+ /* No post work to be done */
+ break;
+ }
+
+ return WORK_FINISHED_CONTINUE;
+}
+
+/*
+ * Construct a message to be sent from the server to the client.
+ *
+ * Valid return values are:
+ * 1: Success
+ * 0: Error
+ */
+static int server_construct_message(SSL *s)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case DTLS_ST_SW_HELLO_VERIFY_REQUEST:
+ return dtls_construct_hello_verify_request(s);
+
+ case TLS_ST_SW_HELLO_REQ:
+ return tls_construct_hello_request(s);
+
+ case TLS_ST_SW_SRVR_HELLO:
+ return tls_construct_server_hello(s);
+
+ case TLS_ST_SW_CERT:
+ return tls_construct_server_certificate(s);
+
+ case TLS_ST_SW_KEY_EXCH:
+ return tls_construct_server_key_exchange(s);
+
+ case TLS_ST_SW_CERT_REQ:
+ return tls_construct_certificate_request(s);
+
+ case TLS_ST_SW_SRVR_DONE:
+ return tls_construct_server_done(s);
+
+ case TLS_ST_SW_SESSION_TICKET:
+ return tls_construct_new_session_ticket(s);
+
+ case TLS_ST_SW_CERT_STATUS:
+ return tls_construct_cert_status(s);
+
+ case TLS_ST_SW_CHANGE:
+ if (SSL_IS_DTLS(s))
+ return dtls_construct_change_cipher_spec(s);
+ else
+ return tls_construct_change_cipher_spec(s);
+
+ case TLS_ST_SW_FINISHED:
+ return tls_construct_finished(s,
+ s->method->
+ ssl3_enc->server_finished_label,
+ s->method->
+ ssl3_enc->server_finished_label_len);
+
+ default:
+ /* Shouldn't happen */
+ break;
+ }
+
+ return 0;
+}
+
+#define CLIENT_KEY_EXCH_MAX_LENGTH 2048
+#define NEXT_PROTO_MAX_LENGTH 514
+
+/*
+ * Returns the maximum allowed length for the current message that we are
+ * reading. Excludes the message header.
+ */
+static unsigned long server_max_message_size(SSL *s)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_SR_CLNT_HELLO:
+ return SSL3_RT_MAX_PLAIN_LENGTH;
+
+ case TLS_ST_SR_CERT:
+ return s->max_cert_list;
+
+ case TLS_ST_SR_KEY_EXCH:
+ return CLIENT_KEY_EXCH_MAX_LENGTH;
+
+ case TLS_ST_SR_CERT_VRFY:
+ return SSL3_RT_MAX_PLAIN_LENGTH;
+
+#ifndef OPENSSL_NO_NEXTPROTONEG
+ case TLS_ST_SR_NEXT_PROTO:
+ return NEXT_PROTO_MAX_LENGTH;
+#endif
+
+ case TLS_ST_SR_CHANGE:
+ return CCS_MAX_LENGTH;
+
+ case TLS_ST_SR_FINISHED:
+ return FINISHED_MAX_LENGTH;
+
+ default:
+ /* Shouldn't happen */
+ break;
+ }
+
+ return 0;
+}
+
+/*
+ * Process a message that the server has received from the client.
+ */
+static enum MSG_PROCESS_RETURN server_process_message(SSL *s, PACKET *pkt)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_SR_CLNT_HELLO:
+ return tls_process_client_hello(s, pkt);
+
+ case TLS_ST_SR_CERT:
+ return tls_process_client_certificate(s, pkt);
+
+ case TLS_ST_SR_KEY_EXCH:
+ return tls_process_client_key_exchange(s, pkt);
+
+ case TLS_ST_SR_CERT_VRFY:
+ return tls_process_cert_verify(s, pkt);
+
+#ifndef OPENSSL_NO_NEXTPROTONEG
+ case TLS_ST_SR_NEXT_PROTO:
+ return tls_process_next_proto(s, pkt);
+#endif
+
+ case TLS_ST_SR_CHANGE:
+ return tls_process_change_cipher_spec(s, pkt);
+
+ case TLS_ST_SR_FINISHED:
+ return tls_process_finished(s, pkt);
+
+ default:
+ /* Shouldn't happen */
+ break;
+ }
+
+ return MSG_PROCESS_ERROR;
+}
+
+/*
+ * Perform any further processing required following the receipt of a message
+ * from the client
+ */
+static enum WORK_STATE server_post_process_message(SSL *s, enum WORK_STATE wst)
+{
+ STATEM *st = &s->statem;
+
+ switch(st->hand_state) {
+ case TLS_ST_SR_CLNT_HELLO:
+ return tls_post_process_client_hello(s, wst);
+
+ case TLS_ST_SR_KEY_EXCH:
+ return tls_post_process_client_key_exchange(s, wst);
+
+ case TLS_ST_SR_CERT_VRFY:
+#ifndef OPENSSL_NO_SCTP
+ if ( /* Is this SCTP? */
+ BIO_dgram_is_sctp(SSL_get_wbio(s))
+ /* Are we renegotiating? */
+ && s->renegotiate
+ && BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
+ s->s3->in_read_app_data = 2;
+ s->rwstate = SSL_READING;
+ BIO_clear_retry_flags(SSL_get_rbio(s));
+ BIO_set_retry_read(SSL_get_rbio(s));
+ statem_set_sctp_read_sock(s, 1);
+ return WORK_MORE_A;
+ } else {
+ statem_set_sctp_read_sock(s, 0);
+ }
+#endif
+ return WORK_FINISHED_CONTINUE;
+
+
+ case TLS_ST_SR_FINISHED:
+ if (s->hit)
+ return tls_finish_handshake(s, wst);
+ else
+ return WORK_FINISHED_STOP;
+ default:
+ break;
+ }
+
+ /* Shouldn't happen */
+ return WORK_ERROR;
+}
