Split TLS server functions

Split the TLS server ssl3_get_* and ssl3_send_* functions into two ready
for the migration to the new state machine code.

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

1 files changed, 1077 insertions, 899 deletions

diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index 376ab7150d..98e831c58e 100644
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -169,7 +169,6 @@ static STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s,
                                                       STACK_OF(SSL_CIPHER) **skp,
                                                       int sslv2format, int *al);
 
-
 #ifndef OPENSSL_NO_SRP
 static int ssl_check_srp_ext_ClientHello(SSL *s, int *al)
 {
@@ -350,37 +349,29 @@ int ssl3_accept(SSL *s)
             ret = ssl3_get_client_hello(s);
             if (ret <= 0)
                 goto end;
+
+            s->state = SSL3_ST_SW_SRVR_HELLO_A;
+            s->init_num = 0;
+            break;
+
 #ifndef OPENSSL_NO_SRP
-            s->state = SSL3_ST_SR_CLNT_HELLO_D;
         case SSL3_ST_SR_CLNT_HELLO_D:
             {
-                int al;
-                if ((ret = ssl_check_srp_ext_ClientHello(s, &al)) < 0) {
-                    /*
-                     * callback indicates firther work to be done
-                     */
-                    s->rwstate = SSL_X509_LOOKUP;
+                enum WORK_STATE wst_ret;
+
+                wst_ret = tls_post_process_client_hello(s, WORK_MORE_B);
+                if (wst_ret == WORK_MORE_B)
                     goto end;
-                }
-                if (ret != SSL_ERROR_NONE) {
-                    ssl3_send_alert(s, SSL3_AL_FATAL, al);
-                    /*
-                     * This is not really an error but the only means to for
-                     * a client to detect whether srp is supported.
-                     */
-                    if (al != TLS1_AD_UNKNOWN_PSK_IDENTITY)
-                        SSLerr(SSL_F_SSL3_ACCEPT, SSL_R_CLIENTHELLO_TLSEXT);
+                if (wst_ret == WORK_ERROR) {
                     ret = -1;
-                    s->state = SSL_ST_ERR;
                     goto end;
                 }
             }
-#endif
 
-            s->renegotiate = 2;
             s->state = SSL3_ST_SW_SRVR_HELLO_A;
             s->init_num = 0;
             break;
+#endif
 
         case SSL3_ST_SW_SRVR_HELLO_A:
         case SSL3_ST_SW_SRVR_HELLO_B:
@@ -569,7 +560,7 @@ int ssl3_accept(SSL *s)
             ret = ssl3_get_client_key_exchange(s);
             if (ret <= 0)
                 goto end;
-            if (ret == 2) {
+            if (s->no_cert_verify) {
                 /*
                  * For the ECDH ciphersuites when the client sends its ECDH
                  * pub key in a certificate, the CertificateVerify message is
@@ -825,8 +816,7 @@ int ssl3_send_hello_request(SSL *s)
 {
 
     if (s->state == SSL3_ST_SW_HELLO_REQ_A) {
-        if (!ssl_set_handshake_header(s, SSL3_MT_HELLO_REQUEST, 0)) {
-            SSLerr(SSL_F_SSL3_SEND_HELLO_REQUEST, ERR_R_INTERNAL_ERROR);
+        if (tls_construct_hello_request(s) == 0) {
             return -1;
         }
         s->state = SSL3_ST_SW_HELLO_REQ_B;
@@ -836,21 +826,22 @@ int ssl3_send_hello_request(SSL *s)
     return ssl_do_write(s);
 }
 
+int tls_construct_hello_request(SSL *s)
+{
+    if (!ssl_set_handshake_header(s, SSL3_MT_HELLO_REQUEST, 0)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_HELLO_REQUEST, ERR_R_INTERNAL_ERROR);
+        statem_set_error(s);
+        return 0;
+    }
+
+    return 1;
+}
+
 int ssl3_get_client_hello(SSL *s)
 {
-    int i, ok, al = SSL_AD_INTERNAL_ERROR, ret = -1;
-    unsigned int j, complen = 0;
+    int ok;
     long n;
-    unsigned long id;
-    SSL_CIPHER *c;
-#ifndef OPENSSL_NO_COMP
-    SSL_COMP *comp = NULL;
-#endif
-    STACK_OF(SSL_CIPHER) *ciphers = NULL;
-    int protverr = 1;
-    /* |cookie| will only be initialized for DTLS. */
-    PACKET pkt, session_id, cipher_suites, compression, extensions, cookie;
-    int is_v2_record;
+    enum WORK_STATE wst_ret;
 
     if (s->state == SSL3_ST_SR_CLNT_HELLO_C && !s->first_packet)
         goto retry_cert;
@@ -874,8 +865,38 @@ int ssl3_get_client_hello(SSL *s)
     if (!ok)
         return ((int)n);
     s->first_packet = 0;
+
+    if (tls_process_client_hello(s, n) == 0)
+        return -1;
+
+ retry_cert:
+    wst_ret = tls_post_process_client_hello(s, WORK_MORE_A);
+    if (wst_ret == WORK_MORE_A || wst_ret == WORK_ERROR)
+        return -1;
+    if (wst_ret == WORK_MORE_B) {
+        s->state = SSL3_ST_SR_CLNT_HELLO_D;
+        return -1;
+    }
+    return n;
+}
+
+enum MSG_PROCESS_RETURN tls_process_client_hello(SSL *s, long n)
+{
+    int i, al = SSL_AD_INTERNAL_ERROR;
+    unsigned int j, complen = 0;
+    unsigned long id;
+    SSL_CIPHER *c;
+#ifndef OPENSSL_NO_COMP
+    SSL_COMP *comp = NULL;
+#endif
+    STACK_OF(SSL_CIPHER) *ciphers = NULL;
+    int protverr = 1;
+    /* |cookie| will only be initialized for DTLS. */
+    PACKET pkt, session_id, cipher_suites, compression, extensions, cookie;
+    int is_v2_record;
+
     if (!PACKET_buf_init(&pkt, s->init_msg, n)) {
-        SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+        SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
         al = SSL_AD_INTERNAL_ERROR;
         goto f_err;
     }
@@ -909,25 +930,25 @@ int ssl3_get_client_hello(SSL *s)
              * layer in order to have determined that this is a SSLv2 record
              * in the first place
              */
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
             goto err;
         }
 
         if (!PACKET_get_net_2(&pkt, &version)) {
             /* No protocol version supplied! */
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
             goto err;
         }
         if (version == 0x0002) {
             /* This is real SSLv2. We don't support it. */
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
             goto err;
         } else if ((version & 0xff00) == (SSL3_VERSION_MAJOR << 8)) {
             /* SSLv3/TLS */
             s->client_version = version;
         } else {
             /* No idea what protocol this is */
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
             goto err;
         }
     } else {
@@ -937,7 +958,7 @@ int ssl3_get_client_hello(SSL *s)
          */
         if(!PACKET_get_net_2(&pkt, (unsigned int *)&s->client_version)) {
             al = SSL_AD_DECODE_ERROR;
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_LENGTH_TOO_SHORT);
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_LENGTH_TOO_SHORT);
             goto f_err;
         }
     }
@@ -998,7 +1019,7 @@ int ssl3_get_client_hello(SSL *s)
     }
 
     if (protverr) {
-        SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
+        SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
         if ((!s->enc_write_ctx && !s->write_hash)) {
             /*
              * similar to ssl3_get_record, send alert using remote version
@@ -1023,7 +1044,8 @@ int ssl3_get_client_hello(SSL *s)
         if (!PACKET_get_net_2(&pkt, &cipher_len)
                 || !PACKET_get_net_2(&pkt, &session_id_len)
                 || !PACKET_get_net_2(&pkt, &challenge_len)) {
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_RECORD_LENGTH_MISMATCH);
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO,
+                   SSL_R_RECORD_LENGTH_MISMATCH);
             al = SSL_AD_DECODE_ERROR;
             goto f_err;
         }
@@ -1135,7 +1157,7 @@ int ssl3_get_client_hello(SSL *s)
     }
 
     if (SSL_IS_DTLS(s)) {
-	/* Empty cookie was already handled above by returning early. */
+        /* Empty cookie was already handled above by returning early. */
         if (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) {
             if (s->ctx->app_verify_cookie_cb != NULL) {
                 if (s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookie),
@@ -1153,8 +1175,7 @@ int ssl3_get_client_hello(SSL *s)
                 SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_COOKIE_MISMATCH);
                 goto f_err;
             }
-            /* Set to -2 so if successful we return 2 */
-            ret = -2;
+            s->d1->cookie_verified = 1;
         }
         if (s->method->version == DTLS_ANY_VERSION) {
             /* Select version to use */
@@ -1278,7 +1299,7 @@ int ssl3_get_client_hello(SSL *s)
                                                                (s));
             if (pref_cipher == NULL) {
                 al = SSL_AD_HANDSHAKE_FAILURE;
-                SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_NO_SHARED_CIPHER);
+                SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_NO_SHARED_CIPHER);
                 goto f_err;
             }
 
@@ -1304,7 +1325,7 @@ int ssl3_get_client_hello(SSL *s)
         /* Perform sanity checks on resumed compression algorithm */
         /* Can't disable compression */
         if (!ssl_allow_compression(s)) {
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO,
                    SSL_R_INCONSISTENT_COMPRESSION);
             goto f_err;
         }
@@ -1317,7 +1338,7 @@ int ssl3_get_client_hello(SSL *s)
             }
         }
         if (s->s3->tmp.new_compression == NULL) {
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO,
                    SSL_R_INVALID_COMPRESSION_ALGORITHM);
             goto f_err;
         }
@@ -1328,7 +1349,7 @@ int ssl3_get_client_hello(SSL *s)
         }
         if (k >= complen) {
             al = SSL_AD_ILLEGAL_PARAMETER;
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO,
                    SSL_R_REQUIRED_COMPRESSSION_ALGORITHM_MISSING);
             goto f_err;
         }
@@ -1363,7 +1384,7 @@ int ssl3_get_client_hello(SSL *s)
      * using compression.
      */
     if (s->session->compress_meth != 0) {
-        SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_INCONSISTENT_COMPRESSION);
+        SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_INCONSISTENT_COMPRESSION);
         goto f_err;
     }
 #endif
@@ -1382,89 +1403,140 @@ int ssl3_get_client_hello(SSL *s)
         s->session->ciphers = ciphers;
         if (ciphers == NULL) {
             al = SSL_AD_INTERNAL_ERROR;
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
             goto f_err;
         }
         ciphers = NULL;
         if (!tls1_set_server_sigalgs(s)) {
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_CLIENTHELLO_TLSEXT);
+            SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_CLIENTHELLO_TLSEXT);
             goto err;
         }
-        /* Let cert callback update server certificates if required */
- retry_cert:
-        if (s->cert->cert_cb) {
-            int rv = s->cert->cert_cb(s, s->cert->cert_cb_arg);
-            if (rv == 0) {
-                al = SSL_AD_INTERNAL_ERROR;
-                SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_CERT_CB_ERROR);
-                goto f_err;
+    }
+
+    sk_SSL_CIPHER_free(ciphers);
+    return MSG_PROCESS_CONTINUE_PROCESSING;
+ f_err:
+    ssl3_send_alert(s, SSL3_AL_FATAL, al);
+ err:
+    statem_set_error(s);
+
+    sk_SSL_CIPHER_free(ciphers);
+    return MSG_PROCESS_ERROR;
+
+}
+
+enum WORK_STATE tls_post_process_client_hello(SSL *s, enum WORK_STATE wst)
+{
+    int al;
+    SSL_CIPHER *cipher;
+
+    if (wst == WORK_MORE_A) {
+        if (!s->hit) {
+            /* Let cert callback update server certificates if required */
+            if (s->cert->cert_cb) {
+                int rv = s->cert->cert_cb(s, s->cert->cert_cb_arg);
+                if (rv == 0) {
+                    al = SSL_AD_INTERNAL_ERROR;
+                    SSLerr(SSL_F_TLS_POST_PROCESS_CLIENT_HELLO, SSL_R_CERT_CB_ERROR);
+                    goto f_err;
+                }
+                if (rv < 0) {
+                    s->rwstate = SSL_X509_LOOKUP;
+                    return WORK_MORE_A;
+                }
+                s->rwstate = SSL_NOTHING;
             }
-            if (rv < 0) {
-                s->rwstate = SSL_X509_LOOKUP;
-                return -1;
+            cipher = ssl3_choose_cipher(s, s->session->ciphers, SSL_get_ciphers(s));
+
+            if (cipher == NULL) {
+                al = SSL_AD_HANDSHAKE_FAILURE;
+                SSLerr(SSL_F_TLS_POST_PROCESS_CLIENT_HELLO, SSL_R_NO_SHARED_CIPHER);
+                goto f_err;
             }
-            s->rwstate = SSL_NOTHING;
+            s->s3->tmp.new_cipher = cipher;
+            /* check whether we should disable session resumption */
+            if (s->not_resumable_session_cb != NULL)
+                s->session->not_resumable = s->not_resumable_session_cb(s,
+                    ((cipher->algorithm_mkey & (SSL_kDHE | SSL_kECDHE)) != 0));
+            if (s->session->not_resumable)
+                /* do not send a session ticket */
+                s->tlsext_ticket_expected = 0;
+        } else {
+            /* Session-id reuse */
+            s->s3->tmp.new_cipher = s->session->cipher;
         }
-        c = ssl3_choose_cipher(s, s->session->ciphers, SSL_get_ciphers(s));
 
-        if (c == NULL) {
-            al = SSL_AD_HANDSHAKE_FAILURE;
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_NO_SHARED_CIPHER);
-            goto f_err;
+        if (!SSL_USE_SIGALGS(s) || !(s->verify_mode & SSL_VERIFY_PEER)) {
+            if (!ssl3_digest_cached_records(s, 0))
+                goto f_err;
         }
-        s->s3->tmp.new_cipher = c;
-        /* check whether we should disable session resumption */
-        if (s->not_resumable_session_cb != NULL)
-            s->session->not_resumable = s->not_resumable_session_cb(s,
-                                                                    ((c->algorithm_mkey & (SSL_kDHE | SSL_kECDHE))
-                                                                     != 0));
-        if (s->session->not_resumable)
-            /* do not send a session ticket */
-            s->tlsext_ticket_expected = 0;
-    } else {
-        /* Session-id reuse */
-        s->s3->tmp.new_cipher = s->session->cipher;
-    }
 
-    if (!SSL_USE_SIGALGS(s) || !(s->verify_mode & SSL_VERIFY_PEER)) {
-        if (!ssl3_digest_cached_records(s, 0))
-            goto f_err;
-    }
+        /*-
+         * we now have the following setup.
+         * client_random
+         * cipher_list          - our prefered list of ciphers
+         * ciphers              - the clients prefered list of ciphers
+         * compression          - basically ignored right now
+         * ssl version is set   - sslv3
+         * s->session           - The ssl session has been setup.
+         * s->hit               - session reuse flag
+         * s->s3->tmp.new_cipher- the new cipher to use.
+         */
 
-    /*-
-     * we now have the following setup.
-     * client_random
-     * cipher_list          - our prefered list of ciphers
-     * ciphers              - the clients prefered list of ciphers
-     * compression          - basically ignored right now
-     * ssl version is set   - sslv3
-     * s->session           - The ssl session has been setup.
-     * s->hit               - session reuse flag
-     * s->s3->tmp.new_cipher- the new cipher to use.
-     */
+        /* Handles TLS extensions that we couldn't check earlier */
+        if (s->version >= SSL3_VERSION) {
+            if (ssl_check_clienthello_tlsext_late(s) <= 0) {
+                SSLerr(SSL_F_TLS_POST_PROCESS_CLIENT_HELLO, SSL_R_CLIENTHELLO_TLSEXT);
+                goto f_err;
+            }
+        }
 
-    /* Handles TLS extensions that we couldn't check earlier */
-    if (s->version >= SSL3_VERSION) {
-        if (ssl_check_clienthello_tlsext_late(s) <= 0) {
-            SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_CLIENTHELLO_TLSEXT);
-            goto err;
+        wst = WORK_MORE_B;
+    }
+#ifndef OPENSSL_NO_SRP
+    if (wst == WORK_MORE_B) {
+        int ret;
+        if ((ret = ssl_check_srp_ext_ClientHello(s, &al)) < 0) {
+            /*
+             * callback indicates further work to be done
+             */
+            s->rwstate = SSL_X509_LOOKUP;
+            return WORK_MORE_B;
+        }
+        if (ret != SSL_ERROR_NONE) {
+            /*
+             * This is not really an error but the only means to for
+             * a client to detect whether srp is supported.
+             */
+            if (al != TLS1_AD_UNKNOWN_PSK_IDENTITY)
+                SSLerr(SSL_F_TLS_POST_PROCESS_CLIENT_HELLO,
+                           SSL_R_CLIENTHELLO_TLSEXT);
+            goto f_err;
         }
     }
+#endif
+    s->renegotiate = 2;
 
-    if (ret < 0)
-        ret = -ret;
-    if (0) {
+    return WORK_FINISHED_STOP;
  f_err:
-        ssl3_send_alert(s, SSL3_AL_FATAL, al);
- err:
-        s->state = SSL_ST_ERR;
+    ssl3_send_alert(s, SSL3_AL_FATAL, al);
+    statem_set_error(s);
+    return WORK_ERROR;
+}
+
+int ssl3_send_server_hello(SSL *s)
+{
+    if (s->state == SSL3_ST_SW_SRVR_HELLO_A) {
+        if (tls_construct_server_hello(s) != 1)
+            return -1;
+        s->state = SSL3_ST_SW_SRVR_HELLO_B;
     }
 
-    sk_SSL_CIPHER_free(ciphers);
-    return ret < 0 ? -1 : ret;
+    /* SSL3_ST_SW_SRVR_HELLO_B */
+    return ssl_do_write(s);
 }
 
-int ssl3_send_server_hello(SSL *s)
+int tls_construct_server_hello(SSL *s)
 {
     unsigned char *buf;
     unsigned char *p, *d;
@@ -1472,102 +1544,97 @@ int ssl3_send_server_hello(SSL *s)
     int al = 0;
     unsigned long l;
 
-    if (s->state == SSL3_ST_SW_SRVR_HELLO_A) {
-        buf = (unsigned char *)s->init_buf->data;
+    buf = (unsigned char *)s->init_buf->data;
 
-        /* Do the message type and length last */
-        d = p = ssl_handshake_start(s);
+    /* Do the message type and length last */
+    d = p = ssl_handshake_start(s);
 
-        *(p++) = s->version >> 8;
-        *(p++) = s->version & 0xff;
+    *(p++) = s->version >> 8;
+    *(p++) = s->version & 0xff;
 
-        /*
-         * Random stuff. Filling of the server_random takes place in
-         * ssl3_get_client_hello()
-         */
-        memcpy(p, s->s3->server_random, SSL3_RANDOM_SIZE);
-        p += SSL3_RANDOM_SIZE;
+    /*
+     * Random stuff. Filling of the server_random takes place in
+     * tls_process_client_hello()
+     */
+    memcpy(p, s->s3->server_random, SSL3_RANDOM_SIZE);
+    p += SSL3_RANDOM_SIZE;
 
-        /*-
-         * There are several cases for the session ID to send
-         * back in the server hello:
-         * - For session reuse from the session cache,
-         *   we send back the old session ID.
-         * - If stateless session reuse (using a session ticket)
-         *   is successful, we send back the client's "session ID"
-         *   (which doesn't actually identify the session).
-         * - If it is a new session, we send back the new
-         *   session ID.
-         * - However, if we want the new session to be single-use,
-         *   we send back a 0-length session ID.
-         * s->hit is non-zero in either case of session reuse,
-         * so the following won't overwrite an ID that we're supposed
-         * to send back.
-         */
-        if (s->session->not_resumable ||
-            (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)
-             && !s->hit))
-            s->session->session_id_length = 0;
-
-        sl = s->session->session_id_length;
-        if (sl > (int)sizeof(s->session->session_id)) {
-            SSLerr(SSL_F_SSL3_SEND_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
-            s->state = SSL_ST_ERR;
-            return -1;
-        }
-        *(p++) = sl;
-        memcpy(p, s->session->session_id, sl);
-        p += sl;
+    /*-
+     * There are several cases for the session ID to send
+     * back in the server hello:
+     * - For session reuse from the session cache,
+     *   we send back the old session ID.
+     * - If stateless session reuse (using a session ticket)
+     *   is successful, we send back the client's "session ID"
+     *   (which doesn't actually identify the session).
+     * - If it is a new session, we send back the new
+     *   session ID.
+     * - However, if we want the new session to be single-use,
+     *   we send back a 0-length session ID.
+     * s->hit is non-zero in either case of session reuse,
+     * so the following won't overwrite an ID that we're supposed
+     * to send back.
+     */
+    if (s->session->not_resumable ||
+        (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)
+         && !s->hit))
+        s->session->session_id_length = 0;
+
+    sl = s->session->session_id_length;
+    if (sl > (int)sizeof(s->session->session_id)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
+        statem_set_error(s);
+        return 0;
+    }
+    *(p++) = sl;
+    memcpy(p, s->session->session_id, sl);
+    p += sl;
 
-        /* put the cipher */
-        i = ssl3_put_cipher_by_char(s->s3->tmp.new_cipher, p);
-        p += i;
+    /* put the cipher */
+    i = ssl3_put_cipher_by_char(s->s3->tmp.new_cipher, p);
+    p += i;
 
-        /* put the compression method */
+    /* put the compression method */
 #ifdef OPENSSL_NO_COMP
-        *(p++) = 0;
+    *(p++) = 0;
 #else
-        if (s->s3->tmp.new_compression == NULL)
-            *(p++) = 0;
-        else
-            *(p++) = s->s3->tmp.new_compression->id;
+    if (s->s3->tmp.new_compression == NULL)
+        *(p++) = 0;
+    else
+        *(p++) = s->s3->tmp.new_compression->id;
 #endif
 
-        if (ssl_prepare_serverhello_tlsext(s) <= 0) {
-            SSLerr(SSL_F_SSL3_SEND_SERVER_HELLO, SSL_R_SERVERHELLO_TLSEXT);
-            s->state = SSL_ST_ERR;
-            return -1;
-        }
-        if ((p =
-             ssl_add_serverhello_tlsext(s, p, buf + SSL3_RT_MAX_PLAIN_LENGTH,
-                                        &al)) == NULL) {
-            ssl3_send_alert(s, SSL3_AL_FATAL, al);
-            SSLerr(SSL_F_SSL3_SEND_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
-            s->state = SSL_ST_ERR;
-            return -1;
-        }
+    if (ssl_prepare_serverhello_tlsext(s) <= 0) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_HELLO, SSL_R_SERVERHELLO_TLSEXT);
+        statem_set_error(s);
+        return 0;
+    }
+    if ((p =
+         ssl_add_serverhello_tlsext(s, p, buf + SSL3_RT_MAX_PLAIN_LENGTH,
+                                    &al)) == NULL) {
+        ssl3_send_alert(s, SSL3_AL_FATAL, al);
+        SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
+        statem_set_error(s);
+        return 0;
+    }
 
-        /* do the header */
-        l = (p - d);
-        if (!ssl_set_handshake_header(s, SSL3_MT_SERVER_HELLO, l)) {
-            SSLerr(SSL_F_SSL3_SEND_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
-            return -1;
-        }
-        s->state = SSL3_ST_SW_SRVR_HELLO_B;
+    /* do the header */
+    l = (p - d);
+    if (!ssl_set_handshake_header(s, SSL3_MT_SERVER_HELLO, l)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
+        statem_set_error(s);
+        return 0;
     }
 
-    /* SSL3_ST_SW_SRVR_HELLO_B */
-    return ssl_do_write(s);
+    return 1;
 }
 
 int ssl3_send_server_done(SSL *s)
 {
 
     if (s->state == SSL3_ST_SW_SRVR_DONE_A) {
-        if (!ssl_set_handshake_header(s, SSL3_MT_SERVER_DONE, 0)) {
-            SSLerr(SSL_F_SSL3_SEND_SERVER_DONE, ERR_R_INTERNAL_ERROR);
+        if (tls_construct_server_done(s) == 0)
             return -1;
-        }
         s->state = SSL3_ST_SW_SRVR_DONE_B;
     }
 
@@ -1575,8 +1642,36 @@ int ssl3_send_server_done(SSL *s)
     return ssl_do_write(s);
 }
 
+int tls_construct_server_done(SSL *s)
+{
+    if (!ssl_set_handshake_header(s, SSL3_MT_SERVER_DONE, 0)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_DONE, ERR_R_INTERNAL_ERROR);
+        statem_set_error(s);
+        return 0;
+    }
+
+    if (!s->s3->tmp.cert_request) {
+        if (!ssl3_digest_cached_records(s, 0)) {
+            statem_set_error(s);
+        }
+    }
+
+    return 1;
+}
+
 int ssl3_send_server_key_exchange(SSL *s)
 {
+    if (s->state == SSL3_ST_SW_KEY_EXCH_A) {
+        if (tls_construct_server_key_exchange(s) == 0)
+            return -1;
+    }
+
+    s->state = SSL3_ST_SW_KEY_EXCH_B;
+    return ssl_do_write(s);
+}
+
+int tls_construct_server_key_exchange(SSL *s)
+{
 #ifndef OPENSSL_NO_RSA
     unsigned char *q;
     int j, num;
@@ -1607,431 +1702,429 @@ int ssl3_send_server_key_exchange(SSL *s)
     EVP_MD_CTX md_ctx;
 
     EVP_MD_CTX_init(&md_ctx);
-    if (s->state == SSL3_ST_SW_KEY_EXCH_A) {
-        type = s->s3->tmp.new_cipher->algorithm_mkey;
-        cert = s->cert;
 
-        buf = s->init_buf;
+    type = s->s3->tmp.new_cipher->algorithm_mkey;
+    cert = s->cert;
+
+    buf = s->init_buf;
 
-        r[0] = r[1] = r[2] = r[3] = NULL;
-        n = 0;
+    r[0] = r[1] = r[2] = r[3] = NULL;
+    n = 0;
 #ifndef OPENSSL_NO_PSK
-        if (type & SSL_PSK) {
-            /*
-             * reserve size for record length and PSK identity hint
-             */
-            n += 2;
-            if (s->cert->psk_identity_hint)
-                n += strlen(s->cert->psk_identity_hint);
-        }
-        /* Plain PSK or RSAPSK nothing to do */
-        if (type & (SSL_kPSK | SSL_kRSAPSK)) {
-        } else
+    if (type & SSL_PSK) {
+        /*
+         * reserve size for record length and PSK identity hint
+         */
+        n += 2;
+        if (s->cert->psk_identity_hint)
+            n += strlen(s->cert->psk_identity_hint);
+    }
+    /* Plain PSK or RSAPSK nothing to do */
+    if (type & (SSL_kPSK | SSL_kRSAPSK)) {
+    } else
 #endif                          /* !OPENSSL_NO_PSK */
 #ifndef OPENSSL_NO_RSA
-        if (type & SSL_kRSA) {
-            rsa = cert->rsa_tmp;
-            if ((rsa == NULL) && (s->cert->rsa_tmp_cb != NULL)) {
-                rsa = s->cert->rsa_tmp_cb(s,
-                                          SSL_C_IS_EXPORT(s->s3->
-                                                          tmp.new_cipher),
-                                          SSL_C_EXPORT_PKEYLENGTH(s->s3->
-                                                                  tmp.new_cipher));
-                if (rsa == NULL) {
-                    al = SSL_AD_HANDSHAKE_FAILURE;
-                    SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
-                           SSL_R_ERROR_GENERATING_TMP_RSA_KEY);
-                    goto f_err;
-                }
-                RSA_up_ref(rsa);
-                cert->rsa_tmp = rsa;
-            }
+    if (type & SSL_kRSA) {
+        rsa = cert->rsa_tmp;
+        if ((rsa == NULL) && (s->cert->rsa_tmp_cb != NULL)) {
+            rsa = s->cert->rsa_tmp_cb(s,
+                                      SSL_C_IS_EXPORT(s->s3->
+                                                      tmp.new_cipher),
+                                      SSL_C_EXPORT_PKEYLENGTH(s->s3->
+                                                              tmp.new_cipher));
             if (rsa == NULL) {
                 al = SSL_AD_HANDSHAKE_FAILURE;
-                SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
-                       SSL_R_MISSING_TMP_RSA_KEY);
+                SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
+                       SSL_R_ERROR_GENERATING_TMP_RSA_KEY);
                 goto f_err;
             }
-            r[0] = rsa->n;
-            r[1] = rsa->e;
-            s->s3->tmp.use_rsa_tmp = 1;
-        } else
+            RSA_up_ref(rsa);
+            cert->rsa_tmp = rsa;
+        }
+        if (rsa == NULL) {
+            al = SSL_AD_HANDSHAKE_FAILURE;
+            SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
+                   SSL_R_MISSING_TMP_RSA_KEY);
+            goto f_err;
+        }
+        r[0] = rsa->n;
+        r[1] = rsa->e;
+        s->s3->tmp.use_rsa_tmp = 1;
+    } else
 #endif
 #ifndef OPENSSL_NO_DH
-        if (type & (SSL_kDHE | SSL_kDHEPSK)) {
-            if (s->cert->dh_tmp_auto) {
-                dhp = ssl_get_auto_dh(s);
-                if (dhp == NULL) {
-                    al = SSL_AD_INTERNAL_ERROR;
-                    SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
-                           ERR_R_INTERNAL_ERROR);
-                    goto f_err;
-                }
-            } else
-                dhp = cert->dh_tmp;
-            if ((dhp == NULL) && (s->cert->dh_tmp_cb != NULL))
-                dhp = s->cert->dh_tmp_cb(s,
-                                         SSL_C_IS_EXPORT(s->s3->
-                                                         tmp.new_cipher),
-                                         SSL_C_EXPORT_PKEYLENGTH(s->s3->
-                                                                 tmp.new_cipher));
+    if (type & (SSL_kDHE | SSL_kDHEPSK)) {
+        if (s->cert->dh_tmp_auto) {
+            dhp = ssl_get_auto_dh(s);
             if (dhp == NULL) {
-                al = SSL_AD_HANDSHAKE_FAILURE;
-                SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
-                       SSL_R_MISSING_TMP_DH_KEY);
-                goto f_err;
-            }
-            if (!ssl_security(s, SSL_SECOP_TMP_DH,
-                              DH_security_bits(dhp), 0, dhp)) {
-                al = SSL_AD_HANDSHAKE_FAILURE;
-                SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
-                       SSL_R_DH_KEY_TOO_SMALL);
-                goto f_err;
-            }
-            if (s->s3->tmp.dh != NULL) {
-                SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
+                al = SSL_AD_INTERNAL_ERROR;
+                SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                        ERR_R_INTERNAL_ERROR);
-                goto err;
+                goto f_err;
             }
+        } else
+            dhp = cert->dh_tmp;
+        if ((dhp == NULL) && (s->cert->dh_tmp_cb != NULL))
+            dhp = s->cert->dh_tmp_cb(s,
+                                     SSL_C_IS_EXPORT(s->s3->
+                                                     tmp.new_cipher),
+                                     SSL_C_EXPORT_PKEYLENGTH(s->s3->
+                                                             tmp.new_cipher));
+        if (dhp == NULL) {
+            al = SSL_AD_HANDSHAKE_FAILURE;
+            SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
+                   SSL_R_MISSING_TMP_DH_KEY);
+            goto f_err;
+        }
+        if (!ssl_security(s, SSL_SECOP_TMP_DH,
+                          DH_security_bits(dhp), 0, dhp)) {
+            al = SSL_AD_HANDSHAKE_FAILURE;
+            SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
+                   SSL_R_DH_KEY_TOO_SMALL);
+            goto f_err;
+        }
+        if (s->s3->tmp.dh != NULL) {
+            SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
+                   ERR_R_INTERNAL_ERROR);
+            goto err;
+        }
 
-            if (s->cert->dh_tmp_auto)
-                dh = dhp;
-            else if ((dh = DHparams_dup(dhp)) == NULL) {
-                SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE, ERR_R_DH_LIB);
+        if (s->cert->dh_tmp_auto)
+            dh = dhp;
+        else if ((dh = DHparams_dup(dhp)) == NULL) {
+            SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE, ERR_R_DH_LIB);
+            goto err;
+        }
+
+        s->s3->tmp.dh = dh;
+        if ((dhp->pub_key == NULL ||
+             dhp->priv_key == NULL ||
+             (s->options & SSL_OP_SINGLE_DH_USE))) {
+            if (!DH_generate_key(dh)) {
+                SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE, ERR_R_DH_LIB);
                 goto err;
             }
-
-            s->s3->tmp.dh = dh;
-            if ((dhp->pub_key == NULL ||
-                 dhp->priv_key == NULL ||
-                 (s->options & SSL_OP_SINGLE_DH_USE))) {
-                if (!DH_generate_key(dh)) {
-                    SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE, ERR_R_DH_LIB);
-                    goto err;
-                }
-            } else {
-                dh->pub_key = BN_dup(dhp->pub_key);
-                dh->priv_key = BN_dup(dhp->priv_key);
-                if ((dh->pub_key == NULL) || (dh->priv_key == NULL)) {
-                    SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE, ERR_R_DH_LIB);
-                    goto err;
-                }
+        } else {
+            dh->pub_key = BN_dup(dhp->pub_key);
+            dh->priv_key = BN_dup(dhp->priv_key);
+            if ((dh->pub_key == NULL) || (dh->priv_key == NULL)) {
+                SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE, ERR_R_DH_LIB);
+                goto err;
             }
-            r[0] = dh->p;
-            r[1] = dh->g;
-            r[2] = dh->pub_key;
-        } else
+        }
+        r[0] = dh->p;
+        r[1] = dh->g;
+        r[2] = dh->pub_key;
+    } else
 #endif
 #ifndef OPENSSL_NO_EC
-        if (type & (SSL_kECDHE | SSL_kECDHEPSK)) {
-            const EC_GROUP *group;
-
-            ecdhp = cert->ecdh_tmp;
-            if (s->cert->ecdh_tmp_auto) {
-                /* Get NID of appropriate shared curve */
-                int nid = tls1_shared_curve(s, -2);
-                if (nid != NID_undef)
-                    ecdhp = EC_KEY_new_by_curve_name(nid);
-            } else if ((ecdhp == NULL) && s->cert->ecdh_tmp_cb) {
-                ecdhp = s->cert->ecdh_tmp_cb(s,
-                                             SSL_C_IS_EXPORT(s->s3->
-                                                             tmp.new_cipher),
-                                             SSL_C_EXPORT_PKEYLENGTH(s->
-                                                                     s3->tmp.new_cipher));
-            }
-            if (ecdhp == NULL) {
-                al = SSL_AD_HANDSHAKE_FAILURE;
-                SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
-                       SSL_R_MISSING_TMP_ECDH_KEY);
-                goto f_err;
-            }
+    if (type & (SSL_kECDHE | SSL_kECDHEPSK)) {
+        const EC_GROUP *group;
 
-            if (s->s3->tmp.ecdh != NULL) {
-                SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
-                       ERR_R_INTERNAL_ERROR);
-                goto err;
-            }
+        ecdhp = cert->ecdh_tmp;
+        if (s->cert->ecdh_tmp_auto) {
+            /* Get NID of appropriate shared curve */
+            int nid = tls1_shared_curve(s, -2);
+            if (nid != NID_undef)
+                ecdhp = EC_KEY_new_by_curve_name(nid);
+        } else if ((ecdhp == NULL) && s->cert->ecdh_tmp_cb) {
+            ecdhp = s-