More state machine reorg

Move some function definitions around within the state machine to make sure
they are in the correct files. Also create a statem_locl.h header for stuff
entirely local to the state machine code and move various definitions into
it.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

7 files changed, 1530 insertions, 1381 deletions

diff --git a/ssl/statem/statem.c b/ssl/statem/statem.c
index 7e4f524ddc..f0b3260829 100644
--- a/ssl/statem/statem.c
+++ b/ssl/statem/statem.c
@@ -58,6 +58,7 @@
 
 #include <openssl/rand.h>
 #include "../ssl_locl.h"
+#include "statem_locl.h"
 
 /*
  * This file implements the SSL/TLS/DTLS state machines.
@@ -83,7 +84,7 @@
  * | Message flow state machine                |            |                 |
  * |                                           |            |                 |
  * | -------------------- -------------------- | Transition | Handshake state |
- * | | MSG_FLOW_READING    | | MSG_FLOW_WRITING    | | Event      | machine         |
+ * | | MSG_FLOW_READING | | MSG_FLOW_WRITING | | Event      | machine         |
  * | | sub-state        | | sub-state        | |----------->|                 |
  * | | machine for      | | machine for      | |            |                 |
  * | | reading messages | | writing messages | |            |                 |
@@ -108,27 +109,6 @@ 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)
 {
@@ -818,7 +798,7 @@ static enum SUB_STATE_RETURN write_state_machine(SSL *s)
 /*
  * Flush the write BIO
  */
-static int statem_flush(SSL *s)
+int statem_flush(SSL *s)
 {
     s->rwstate = SSL_WRITING;
     if (BIO_flush(s->wbio) <= 0) {
@@ -867,7 +847,6 @@ int statem_app_data_allowed(SSL *s)
     return 0;
 }
 
-
 #ifndef OPENSSL_NO_SCTP
 /*
  * Set flag used by SCTP to determine whether we are in the read sock state
@@ -890,1352 +869,3 @@ 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 */
-