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>

1 files changed, 0 insertions, 2251 deletions

diff --git a/ssl/statem.c b/ssl/statem.c
deleted file mode 100644
index 81af75c4d5..0000000000
--- a/ssl/statem.c
+++ /dev/null
@@ -1,2251 +0,0 @@
-/* ssl/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 ssl3_connect(SSL *s) {
-    return state_machine(s, 0);
-}
-
-int dtls1_connect(SSL *s)
-{
-    return state_machine(s, 0);
-}
-
-int ssl3_accept(SSL *s)
-{
-    return state_machine(s, 1);
-}
-
-int dtls1_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;
-                    re