Process incoming NewSessionTicket messages on the client side
[openssl.git] / ssl / statem / statem_clnt.c
index bef2583c323e3fda918024259a93abce055124e1..45177ece207fd8c6d5bf6f33e8fa3f4674517d3f 100644 (file)
 #include <openssl/bn.h>
 #include <openssl/engine.h>
 
+static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt);
+
 static ossl_inline int cert_req_allowed(SSL *s);
 static int key_exchange_expected(SSL *s);
 static int ca_dn_cmp(const X509_NAME *const *a, const X509_NAME *const *b);
 static int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
-                                    unsigned char *p);
-
+                                    WPACKET *pkt);
 
 /*
  * Is a CertificateRequest message allowed at the moment or not?
@@ -77,8 +78,8 @@ static ossl_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))
-            || (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aSRP | SSL_aPSK)))
+         && (s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL))
+        || (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aSRP | SSL_aPSK)))
         return 0;
 
     return 1;
@@ -107,22 +108,120 @@ static int key_exchange_expected(SSL *s)
     return 0;
 }
 
+/*
+ * ossl_statem_client_read_transition() encapsulates the logic for the allowed
+ * handshake state transitions when a TLS1.3 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 for success (transition allowed) and  0 on error
+ * (transition not allowed)
+ */
+static int ossl_statem_client13_read_transition(SSL *s, int mt)
+{
+    OSSL_STATEM *st = &s->statem;
+
+    /*
+     * TODO(TLS1.3): This is still based on the TLSv1.2 state machine. Over time
+     * we will update this to look more like real TLSv1.3
+     */
+
+    /*
+     * Note: There is no case for TLS_ST_CW_CLNT_HELLO, because we haven't
+     * yet negotiated TLSv1.3 at that point so that is handled by
+     * ossl_statem_client_read_transition()
+     */
+
+    switch (st->hand_state) {
+    default:
+        break;
+
+    case TLS_ST_CR_SRVR_HELLO:
+        if (mt == SSL3_MT_ENCRYPTED_EXTENSIONS) {
+            st->hand_state = TLS_ST_CR_ENCRYPTED_EXTENSIONS;
+            return 1;
+        }
+        break;
+
+    case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
+        if (s->hit) {
+            if (mt == SSL3_MT_FINISHED) {
+                st->hand_state = TLS_ST_CR_FINISHED;
+                return 1;
+            }
+        } else {
+            if (mt == SSL3_MT_CERTIFICATE_REQUEST) {
+                st->hand_state = TLS_ST_CR_CERT_REQ;
+                return 1;
+            }
+            if (mt == SSL3_MT_CERTIFICATE) {
+                st->hand_state = TLS_ST_CR_CERT;
+                return 1;
+            }
+        }
+        break;
+
+    case TLS_ST_CR_CERT_REQ:
+        if (mt == SSL3_MT_CERTIFICATE) {
+            st->hand_state = TLS_ST_CR_CERT;
+            return 1;
+        }
+        break;
+
+    case TLS_ST_CR_CERT:
+        if (mt == SSL3_MT_CERTIFICATE_VERIFY) {
+            st->hand_state = TLS_ST_CR_CERT_VRFY;
+            return 1;
+        }
+        break;
+
+    case TLS_ST_CR_CERT_VRFY:
+        if (mt == SSL3_MT_FINISHED) {
+            st->hand_state = TLS_ST_CR_FINISHED;
+            return 1;
+        }
+        break;
+
+    case TLS_ST_OK:
+        if (mt == SSL3_MT_NEWSESSION_TICKET) {
+            st->hand_state = TLS_ST_CR_SESSION_TICKET;
+            return 1;
+        }
+        break;
+    }
+
+    /* No valid transition found */
+    return 0;
+}
+
 /*
  * ossl_statem_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)
+ * Return values are 1 for success (transition allowed) and  0 on error
+ * (transition not allowed)
  */
 int ossl_statem_client_read_transition(SSL *s, int mt)
 {
     OSSL_STATEM *st = &s->statem;
     int ske_expected;
 
-    switch(st->hand_state) {
+    /*
+     * Note that after a ClientHello we don't know what version we are going
+     * to negotiate yet, so we don't take this branch until later
+     */
+    if (SSL_IS_TLS13(s)) {
+        if (!ossl_statem_client13_read_transition(s, mt))
+            goto err;
+        return 1;
+    }
+
+    switch (st->hand_state) {
+    default:
+        break;
+
     case TLS_ST_CW_CLNT_HELLO:
         if (mt == SSL3_MT_SERVER_HELLO) {
             st->hand_state = TLS_ST_CR_SRVR_HELLO;
@@ -139,7 +238,7 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
 
     case TLS_ST_CR_SRVR_HELLO:
         if (s->hit) {
-            if (s->tlsext_ticket_expected) {
+            if (s->ext.ticket_expected) {
                 if (mt == SSL3_MT_NEWSESSION_TICKET) {
                     st->hand_state = TLS_ST_CR_SESSION_TICKET;
                     return 1;
@@ -153,9 +252,9 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
                 st->hand_state = DTLS_ST_CR_HELLO_VERIFY_REQUEST;
                 return 1;
             } else if (s->version >= TLS1_VERSION
-                    && s->tls_session_secret_cb != NULL
-                    && s->session->tlsext_tick != NULL
-                    && mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+                       && s->ext.session_secret_cb != NULL
+                       && s->session->ext.tick != NULL
+                       && mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
                 /*
                  * Normally, we can tell if the server is resuming the session
                  * from the session ID. EAP-FAST (RFC 4851), however, relies on
@@ -166,7 +265,7 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
                 st->hand_state = TLS_ST_CR_CHANGE;
                 return 1;
             } else if (!(s->s3->tmp.new_cipher->algorithm_auth
-                        & (SSL_aNULL | SSL_aSRP | SSL_aPSK))) {
+                         & (SSL_aNULL | SSL_aSRP | SSL_aPSK))) {
                 if (mt == SSL3_MT_CERTIFICATE) {
                     st->hand_state = TLS_ST_CR_CERT;
                     return 1;
@@ -175,19 +274,19 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
                 ske_expected = key_exchange_expected(s);
                 /* SKE is optional for some PSK ciphersuites */
                 if (ske_expected
-                        || ((s->s3->tmp.new_cipher->algorithm_mkey & SSL_PSK)
-                            && mt == SSL3_MT_SERVER_KEY_EXCHANGE)) {
+                    || ((s->s3->tmp.new_cipher->algorithm_mkey & SSL_PSK)
+                        && mt == SSL3_MT_SERVER_KEY_EXCHANGE)) {
                     if (mt == SSL3_MT_SERVER_KEY_EXCHANGE) {
                         st->hand_state = TLS_ST_CR_KEY_EXCH;
                         return 1;
                     }
                 } else if (mt == SSL3_MT_CERTIFICATE_REQUEST
-                            && cert_req_allowed(s)) {
-                        st->hand_state = TLS_ST_CR_CERT_REQ;
-                        return 1;
+                           && 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;
+                    st->hand_state = TLS_ST_CR_SRVR_DONE;
+                    return 1;
                 }
             }
         }
@@ -196,9 +295,9 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
     case TLS_ST_CR_CERT:
         /*
          * The CertificateStatus message is optional even if
-         * |tlsext_status_expected| is set
+         * |ext.status_expected| is set
          */
-        if (s->tlsext_status_expected && mt == SSL3_MT_CERTIFICATE_STATUS) {
+        if (s->ext.status_expected && mt == SSL3_MT_CERTIFICATE_STATUS) {
             st->hand_state = TLS_ST_CR_CERT_STATUS;
             return 1;
         }
@@ -207,9 +306,8 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
     case TLS_ST_CR_CERT_STATUS:
         ske_expected = key_exchange_expected(s);
         /* SKE is optional for some PSK ciphersuites */
-        if (ske_expected
-                || ((s->s3->tmp.new_cipher->algorithm_mkey & SSL_PSK)
-                    && mt == SSL3_MT_SERVER_KEY_EXCHANGE)) {
+        if (ske_expected || ((s->s3->tmp.new_cipher->algorithm_mkey & SSL_PSK)
+                             && mt == SSL3_MT_SERVER_KEY_EXCHANGE)) {
             if (mt == SSL3_MT_SERVER_KEY_EXCHANGE) {
                 st->hand_state = TLS_ST_CR_KEY_EXCH;
                 return 1;
@@ -236,7 +334,7 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
         break;
 
     case TLS_ST_CW_FINISHED:
-        if (s->tlsext_ticket_expected) {
+        if (s->ext.ticket_expected) {
             if (mt == SSL3_MT_NEWSESSION_TICKET) {
                 st->hand_state = TLS_ST_CR_SESSION_TICKET;
                 return 1;
@@ -261,7 +359,11 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
         }
         break;
 
-    default:
+    case TLS_ST_OK:
+        if (mt == SSL3_MT_HELLO_REQUEST) {
+            st->hand_state = TLS_ST_CR_HELLO_REQ;
+            return 1;
+        }
         break;
     }
 
@@ -273,106 +375,189 @@ int ossl_statem_client_read_transition(SSL *s, int mt)
 }
 
 /*
- * client_write_transition() works out what handshake state to move to next
- * when the client is writing messages to be sent to the server.
+ * ossl_statem_client13_write_transition() works out what handshake state to
+ * move to next when the TLSv1.3 client is writing messages to be sent to the
+ * server.
+ */
+static WRITE_TRAN ossl_statem_client13_write_transition(SSL *s)
+{
+    OSSL_STATEM *st = &s->statem;
+
+    /*
+     * TODO(TLS1.3): This is still based on the TLSv1.2 state machine. Over time
+     * we will update this to look more like real TLSv1.3
+     */
+
+    /*
+     * Note: There are no cases for TLS_ST_BEFORE or TLS_ST_CW_CLNT_HELLO,
+     * because we haven't negotiated TLSv1.3 yet at that point. They are
+     * handled by ossl_statem_client_write_transition().
+     */
+    switch (st->hand_state) {
+    default:
+        /* Shouldn't happen */
+        return WRITE_TRAN_ERROR;
+
+    case TLS_ST_CR_FINISHED:
+        st->hand_state = (s->s3->tmp.cert_req != 0) ? TLS_ST_CW_CERT
+                                                    : TLS_ST_CW_FINISHED;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CW_CERT:
+        /* If a non-empty Certificate we also send CertificateVerify */
+        st->hand_state = (s->s3->tmp.cert_req == 1) ? TLS_ST_CW_CERT_VRFY
+                                                    : TLS_ST_CW_FINISHED;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CW_CERT_VRFY:
+        st->hand_state = TLS_ST_CW_FINISHED;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CR_SESSION_TICKET:
+    case TLS_ST_CW_FINISHED:
+        st->hand_state = TLS_ST_OK;
+        ossl_statem_set_in_init(s, 0);
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_OK:
+        /* Just go straight to trying to read from the server */
+        return WRITE_TRAN_FINISHED;
+    }
+}
+
+/*
+ * ossl_statem_client_write_transition() works out what handshake state to
+ * move to next when the client is writing messages to be sent to the server.
  */
 WRITE_TRAN ossl_statem_client_write_transition(SSL *s)
 {
     OSSL_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;
+    /*
+     * Note that immediately before/after a ClientHello we don't know what
+     * version we are going to negotiate yet, so we don't take this branch until
+     * later
+     */
+    if (SSL_IS_TLS13(s))
+        return ossl_statem_client13_write_transition(s);
+
+    switch (st->hand_state) {
+    default:
+        /* Shouldn't happen */
+        return WRITE_TRAN_ERROR;
 
-        case TLS_ST_CW_CLNT_HELLO:
+    case TLS_ST_OK:
+        if (!s->renegotiate) {
             /*
-             * No transition at the end of writing because we don't know what
-             * we will be sent
+             * We haven't requested a renegotiation ourselves so we must have
+             * received a message from the server. Better read it.
              */
             return WRITE_TRAN_FINISHED;
+        }
+        /* Renegotiation - fall through */
+    case TLS_ST_BEFORE:
+        st->hand_state = TLS_ST_CW_CLNT_HELLO;
+        return WRITE_TRAN_CONTINUE;
 
-        case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
-            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 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 DTLS_ST_CR_HELLO_VERIFY_REQUEST:
+        st->hand_state = TLS_ST_CW_CLNT_HELLO;
+        return WRITE_TRAN_CONTINUE;
 
-        case TLS_ST_CW_CERT:
+    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;
+        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:
+        st->hand_state = TLS_ST_CW_KEY_EXCH;
+        return WRITE_TRAN_CONTINUE;
 
-        case TLS_ST_CW_CERT_VRFY:
+    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;
-            return WRITE_TRAN_CONTINUE;
+        }
+        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:
+    case TLS_ST_CW_CHANGE:
 #if defined(OPENSSL_NO_NEXTPROTONEG)
-            st->hand_state = TLS_ST_CW_FINISHED;
+        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;
+        if (!SSL_IS_DTLS(s) && s->s3->npn_seen)
+            st->hand_state = TLS_ST_CW_NEXT_PROTO;
+        else
+            st->hand_state = TLS_ST_CW_FINISHED;
 #endif
-            return WRITE_TRAN_CONTINUE;
+        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;
+    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;
-                ossl_statem_set_in_init(s, 0);
-                return WRITE_TRAN_CONTINUE;
-            } else {
-                return WRITE_TRAN_FINISHED;
-            }
+    case TLS_ST_CW_FINISHED:
+        if (s->hit) {
+            st->hand_state = TLS_ST_OK;
+            ossl_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;
-                ossl_statem_set_in_init(s, 0);
-                return WRITE_TRAN_CONTINUE;
-            }
+    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;
+            ossl_statem_set_in_init(s, 0);
+            return WRITE_TRAN_CONTINUE;
+        }
 
-        default:
-            /* Shouldn't happen */
-            return WRITE_TRAN_ERROR;
+    case TLS_ST_CR_HELLO_REQ:
+        /*
+         * If we can renegotiate now then do so, otherwise wait for a more
+         * convenient time.
+         */
+        if (ssl3_renegotiate_check(s, 1)) {
+            if (!tls_setup_handshake(s)) {
+                ossl_statem_set_error(s);
+                return WRITE_TRAN_ERROR;
+            }
+            st->hand_state = TLS_ST_CW_CLNT_HELLO;
+            return WRITE_TRAN_CONTINUE;
+        }
+        st->hand_state = TLS_ST_OK;
+        ossl_statem_set_in_init(s, 0);
+        return WRITE_TRAN_CONTINUE;
     }
 }
 
@@ -384,7 +569,11 @@ WORK_STATE ossl_statem_client_pre_work(SSL *s, WORK_STATE wst)
 {
     OSSL_STATEM *st = &s->statem;
 
-    switch(st->hand_state) {
+    switch (st->hand_state) {
+    default:
+        /* No pre work to be done */
+        break;
+
     case TLS_ST_CW_CLNT_HELLO:
         s->shutdown = 0;
         if (SSL_IS_DTLS(s)) {
@@ -410,14 +599,10 @@ WORK_STATE ossl_statem_client_pre_work(SSL *s, WORK_STATE wst)
                 return dtls_wait_for_dry(s);
 #endif
         }
-        return WORK_FINISHED_CONTINUE;
+        break;
 
     case TLS_ST_OK:
-        return tls_finish_handshake(s, wst);
-
-    default:
-        /* No pre work to be done */
-        break;
+        return tls_finish_handshake(s, wst, 1);
     }
 
     return WORK_FINISHED_CONTINUE;
@@ -426,6 +611,8 @@ WORK_STATE ossl_statem_client_pre_work(SSL *s, WORK_STATE wst)
 /*
  * Perform any work that needs to be done after sending a message from the
  * client to the server.
+    case TLS_ST_SR_CERT_VRFY:
+        return SSL3_RT_MAX_PLAIN_LENGTH;
  */
 WORK_STATE ossl_statem_client_post_work(SSL *s, WORK_STATE wst)
 {
@@ -433,7 +620,11 @@ WORK_STATE ossl_statem_client_post_work(SSL *s, WORK_STATE wst)
 
     s->init_num = 0;
 
-    switch(st->hand_state) {
+    switch (st->hand_state) {
+    default:
+        /* No post work to be done */
+        break;
+
     case TLS_ST_CW_CLNT_HELLO:
         if (wst == WORK_MORE_A && statem_flush(s) != 1)
             return WORK_MORE_A;
@@ -495,10 +686,12 @@ WORK_STATE ossl_statem_client_post_work(SSL *s, WORK_STATE wst)
 #endif
         if (statem_flush(s) != 1)
             return WORK_MORE_B;
-        break;
 
-    default:
-        /* No post work to be done */
+        if (SSL_IS_TLS13(s)) {
+            if (!s->method->ssl3_enc->change_cipher_state(s,
+                        SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_CLIENT_WRITE))
+            return WORK_ERROR;
+        }
         break;
     }
 
@@ -506,103 +699,122 @@ WORK_STATE ossl_statem_client_post_work(SSL *s, WORK_STATE wst)
 }
 
 /*
- * Construct a message to be sent from the client to the server.
+ * Get the message construction function and message type for sending from the
+ * client
  *
  * Valid return values are:
  *   1: Success
  *   0: Error
  */
-int ossl_statem_client_construct_message(SSL *s)
+int ossl_statem_client_construct_message(SSL *s, WPACKET *pkt,
+                                         confunc_f *confunc, int *mt)
 {
     OSSL_STATEM *st = &s->statem;
 
-    switch(st->hand_state) {
+    switch (st->hand_state) {
+    default:
+        /* Shouldn't happen */
+        return 0;
+
+    case TLS_ST_CW_CHANGE:
+        if (SSL_IS_DTLS(s))
+            *confunc = dtls_construct_change_cipher_spec;
+        else
+            *confunc = tls_construct_change_cipher_spec;
+        *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
+        break;
+
     case TLS_ST_CW_CLNT_HELLO:
-        return tls_construct_client_hello(s);
+        *confunc = tls_construct_client_hello;
+        *mt = SSL3_MT_CLIENT_HELLO;
+        break;
 
     case TLS_ST_CW_CERT:
-        return tls_construct_client_certificate(s);
+        *confunc = tls_construct_client_certificate;
+        *mt = SSL3_MT_CERTIFICATE;
+        break;
 
     case TLS_ST_CW_KEY_EXCH:
-        return tls_construct_client_key_exchange(s);
+        *confunc = tls_construct_client_key_exchange;
+        *mt = SSL3_MT_CLIENT_KEY_EXCHANGE;
+        break;
 
     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);
+        *confunc = tls_construct_cert_verify;
+        *mt = SSL3_MT_CERTIFICATE_VERIFY;
+        break;
 
 #if !defined(OPENSSL_NO_NEXTPROTONEG)
     case TLS_ST_CW_NEXT_PROTO:
-        return tls_construct_next_proto(s);
+        *confunc = tls_construct_next_proto;
+        *mt = SSL3_MT_NEXT_PROTO;
+        break;
 #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 */
+        *confunc = tls_construct_finished;
+        *mt = SSL3_MT_FINISHED;
         break;
     }
 
-    return 0;
+    return 1;
 }
 
 /*
  * Returns the maximum allowed length for the current message that we are
  * reading. Excludes the message header.
  */
-unsigned long ossl_statem_client_max_message_size(SSL *s)
+size_t ossl_statem_client_max_message_size(SSL *s)
 {
     OSSL_STATEM *st = &s->statem;
 
-    switch(st->hand_state) {
-        case TLS_ST_CR_SRVR_HELLO:
-            return SERVER_HELLO_MAX_LENGTH;
+    switch (st->hand_state) {
+    default:
+        /* Shouldn't happen */
+        return 0;
+
+    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 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:
+        return s->max_cert_list;
 
-        case TLS_ST_CR_CERT_STATUS:
-            return SSL3_RT_MAX_PLAIN_LENGTH;
+    case TLS_ST_CR_CERT_VRFY:
+        return SSL3_RT_MAX_PLAIN_LENGTH;
 
-        case TLS_ST_CR_KEY_EXCH:
-            return SERVER_KEY_EXCH_MAX_LENGTH;
+    case TLS_ST_CR_CERT_STATUS:
+        return SSL3_RT_MAX_PLAIN_LENGTH;
 
-        case TLS_ST_CR_CERT_REQ:
-            /* Set to s->max_cert_list for compatibility with previous releases.
-             * In practice these messages can get quite long if servers are
-             * configured to provide a long list of acceptable CAs
-             */
-            return s->max_cert_list;
+    case TLS_ST_CR_KEY_EXCH:
+        return SERVER_KEY_EXCH_MAX_LENGTH;
+
+    case TLS_ST_CR_CERT_REQ:
+        /*
+         * Set to s->max_cert_list for compatibility with previous releases. In
+         * practice these messages can get quite long if servers are configured
+         * to provide a long list of acceptable CAs
+         */
+        return s->max_cert_list;
 
-        case TLS_ST_CR_SRVR_DONE:
-            return SERVER_HELLO_DONE_MAX_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_CHANGE:
+        if (s->version == DTLS1_BAD_VER)
+            return 3;
+        return CCS_MAX_LENGTH;
 
-        case TLS_ST_CR_SESSION_TICKET:
-            return SSL3_RT_MAX_PLAIN_LENGTH;
+    case TLS_ST_CR_SESSION_TICKET:
+        return SSL3_RT_MAX_PLAIN_LENGTH;
 
-        case TLS_ST_CR_FINISHED:
-            return FINISHED_MAX_LENGTH;
+    case TLS_ST_CR_FINISHED:
+        return FINISHED_MAX_LENGTH;
 
-        default:
-            /* Shouldn't happen */
-            break;
+    case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
+        return ENCRYPTED_EXTENSIONS_MAX_LENGTH;
     }
-
-    return 0;
 }
 
 /*
@@ -612,43 +824,50 @@ MSG_PROCESS_RETURN ossl_statem_client_process_message(SSL *s, PACKET *pkt)
 {
     OSSL_STATEM *st = &s->statem;
 
-    switch(st->hand_state) {
-        case TLS_ST_CR_SRVR_HELLO:
-            return tls_process_server_hello(s, pkt);
+    switch (st->hand_state) {
+    default:
+        /* Shouldn't happen */
+        return MSG_PROCESS_ERROR;
+
+    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 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_VRFY:
+        return tls_process_cert_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_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_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_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_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_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_SESSION_TICKET:
-            return tls_process_new_session_ticket(s, pkt);
+    case TLS_ST_CR_FINISHED:
+        return tls_process_finished(s, pkt);
 
-        case TLS_ST_CR_FINISHED:
-            return tls_process_finished(s, pkt);
+    case TLS_ST_CR_HELLO_REQ:
+        return tls_process_hello_req(s, pkt);
 
-        default:
-            /* Shouldn't happen */
-            break;
+    case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
+        return tls_process_encrypted_extensions(s, pkt);
     }
-
-    return MSG_PROCESS_ERROR;
 }
 
 /*
@@ -659,9 +878,13 @@ WORK_STATE ossl_statem_client_post_process_message(SSL *s, WORK_STATE wst)
 {
     OSSL_STATEM *st = &s->statem;
 
-    switch(st->hand_state) {
-    case TLS_ST_CR_CERT_REQ:
-        return tls_prepare_client_certificate(s, wst);
+    switch (st->hand_state) {
+    default:
+        /* Shouldn't happen */
+        return WORK_ERROR;
+
+    case TLS_ST_CR_CERT_REQ:
+        return tls_prepare_client_certificate(s, wst);
 
 #ifndef OPENSSL_NO_SCTP
     case TLS_ST_CR_SRVR_DONE:
@@ -677,51 +900,48 @@ WORK_STATE ossl_statem_client_post_process_message(SSL *s, WORK_STATE wst)
         ossl_statem_set_sctp_read_sock(s, 0);
         return WORK_FINISHED_STOP;
 #endif
-
-    default:
-        break;
     }
-
-    /* Shouldn't happen */
-    return WORK_ERROR;
 }
 
-int tls_construct_client_hello(SSL *s)
+int tls_construct_client_hello(SSL *s, WPACKET *pkt)
 {
-    unsigned char *buf;
-    unsigned char *p, *d;
-    int i;
-    int protverr;
-    unsigned long l;
-    int al = 0;
+    unsigned char *p;
+    size_t sess_id_len;
+    int i, protverr;
+    int al = SSL_AD_HANDSHAKE_FAILURE;
 #ifndef OPENSSL_NO_COMP
-    int j;
     SSL_COMP *comp;
 #endif
     SSL_SESSION *sess = s->session;
 
-    buf = (unsigned char *)s->init_buf->data;
+    if (!WPACKET_set_max_size(pkt, SSL3_RT_MAX_PLAIN_LENGTH)) {
+        /* Should not happen */
+        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
 
     /* Work out what SSL/TLS/DTLS version to use */
     protverr = ssl_set_client_hello_version(s);
     if (protverr != 0) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, protverr);
-        goto err;
+        return 0;
     }
 
-    if ((sess == NULL) ||
-        !ssl_version_supported(s, sess->ssl_version) ||
+    if ((sess == NULL) || !ssl_version_supported(s, sess->ssl_version) ||
         /*
          * In the case of EAP-FAST, we can have a pre-shared
          * "ticket" without a session ID.
          */
-        (!sess->session_id_length && !sess->tlsext_tick) ||
+        (!sess->session_id_length && !sess->ext.tick) ||
         (sess->not_resumable)) {
         if (!ssl_get_new_session(s, 0))
-            goto err;
+            return 0;
     }
     /* else use the pre-loaded session */
 
+    /* This is a real handshake so make sure we clean it up at the end */
+    s->statem.cleanuphand = 1;
+
     p = s->s3->client_random;
 
     /*
@@ -740,12 +960,8 @@ int tls_construct_client_hello(SSL *s)
     } else
         i = 1;
 
-    if (i && ssl_fill_hello_random(s, 0, p,
-                                   sizeof(s->s3->client_random)) <= 0)
-        goto err;
-
-    /* Do the message type and length last */
-    d = p = ssl_handshake_start(s);
+    if (i && ssl_fill_hello_random(s, 0, p, sizeof(s->s3->client_random)) <= 0)
+        return 0;
 
     /*-
      * version indicates the negotiated version: for example from
@@ -776,110 +992,94 @@ int tls_construct_client_hello(SSL *s)
      * TLS 1.0 and renegotiating with TLS 1.2. We do this by using
      * client_version in client hello and not resetting it to
      * the negotiated version.
+     *
+     * For TLS 1.3 we always set the ClientHello version to 1.2 and rely on the
+     * supported_versions extension for the real supported versions.
      */
-    *(p++) = s->client_version >> 8;
-    *(p++) = s->client_version & 0xff;
-
-    /* Random stuff */
-    memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
-    p += SSL3_RANDOM_SIZE;
+    if (!WPACKET_put_bytes_u16(pkt, s->client_version)
+            || !WPACKET_memcpy(pkt, s->s3->client_random, SSL3_RANDOM_SIZE)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
 
     /* Session ID */
     if (s->new_session)
-        i = 0;
+        sess_id_len = 0;
     else
-        i = s->session->session_id_length;
-    *(p++) = i;
-    if (i != 0) {
-        if (i > (int)sizeof(s->session->session_id)) {
-            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
-            goto err;
-        }
-        memcpy(p, s->session->session_id, i);
-        p += i;
+        sess_id_len = s->session->session_id_length;
+    if (sess_id_len > sizeof(s->session->session_id)
+            || !WPACKET_start_sub_packet_u8(pkt)
+            || (sess_id_len != 0 && !WPACKET_memcpy(pkt, s->session->session_id,
+                                                    sess_id_len))
+            || !WPACKET_close(pkt)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+        return 0;
     }
 
     /* cookie stuff for DTLS */
     if (SSL_IS_DTLS(s)) {
-        if (s->d1->cookie_len > sizeof(s->d1->cookie)) {
+        if (s->d1->cookie_len > sizeof(s->d1->cookie)
+                || !WPACKET_sub_memcpy_u8(pkt, s->d1->cookie,
+                                          s->d1->cookie_len)) {
             SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
-            goto err;
+            return 0;
         }
-        *(p++) = s->d1->cookie_len;
-        memcpy(p, s->d1->cookie, s->d1->cookie_len);
-        p += s->d1->cookie_len;
     }
 
     /* Ciphers supported */
-    i = ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), &(p[2]));
-    if (i == 0) {
-        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, SSL_R_NO_CIPHERS_AVAILABLE);
-        goto err;
+    if (!WPACKET_start_sub_packet_u16(pkt)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+    /* ssl_cipher_list_to_bytes() raises SSLerr if appropriate */
+    if (!ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), pkt))
+        return 0;
+    if (!WPACKET_close(pkt)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+        return 0;
     }
-#ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
-    /*
-     * Some servers hang if client hello > 256 bytes as hack workaround
-     * chop number of supported ciphers to keep it well below this if we
-     * use TLS v1.2
-     */
-    if (TLS1_get_version(s) >= TLS1_2_VERSION
-        && i > OPENSSL_MAX_TLS1_2_CIPHER_LENGTH)
-        i = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
-#endif
-    s2n(i, p);
-    p += i;
 
     /* COMPRESSION */
-#ifdef OPENSSL_NO_COMP
-    *(p++) = 1;
-#else
-
-    if (!ssl_allow_compression(s) || !s->ctx->comp_methods)
-        j = 0;
-    else
-        j = sk_SSL_COMP_num(s->ctx->comp_methods);
-    *(p++) = 1 + j;
-    for (i = 0; i < j; i++) {
-        comp = sk_SSL_COMP_value(s->ctx->comp_methods, i);
-        *(p++) = comp->id;
+    if (!WPACKET_start_sub_packet_u8(pkt)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+        return 0;
     }
-#endif
-    *(p++) = 0;             /* Add the NULL method */
-
-    /* TLS extensions */
-    if (ssl_prepare_clienthello_tlsext(s) <= 0) {
-        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, SSL_R_CLIENTHELLO_TLSEXT);
-        goto err;
+#ifndef OPENSSL_NO_COMP
+    if (ssl_allow_compression(s) && s->ctx->comp_methods) {
+        int compnum = sk_SSL_COMP_num(s->ctx->comp_methods);
+        for (i = 0; i < compnum; i++) {
+            comp = sk_SSL_COMP_value(s->ctx->comp_methods, i);
+            if (!WPACKET_put_bytes_u8(pkt, comp->id)) {
+                SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+                return 0;
+            }
+        }
     }
-    if ((p =
-         ssl_add_clienthello_tlsext(s, p, buf + SSL3_RT_MAX_PLAIN_LENGTH,
-                                    &al)) == NULL) {
-        ssl3_send_alert(s, SSL3_AL_FATAL, al);
+#endif
+    /* Add the NULL method */
+    if (!WPACKET_put_bytes_u8(pkt, 0) || !WPACKET_close(pkt)) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
-        goto err;
+        return 0;
     }
 
-    l = p - d;
-    if (!ssl_set_handshake_header(s, SSL3_MT_CLIENT_HELLO, l)) {
-        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
+    /* TLS extensions */
+    if (!tls_construct_extensions(s, pkt, EXT_CLIENT_HELLO, NULL, 0, &al)) {
+        ssl3_send_alert(s, SSL3_AL_FATAL, al);
         SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
-        goto err;
+        return 0;
     }
 
     return 1;
- err:
-    ossl_statem_set_error(s);
-    return 0;
 }
 
 MSG_PROCESS_RETURN dtls_process_hello_verify(SSL *s, PACKET *pkt)
 {
     int al;
-    unsigned int cookie_len;
+    size_t cookie_len;
     PACKET cookiepkt;
 
     if (!PACKET_forward(pkt, 2)
-            || !PACKET_get_length_prefixed_1(pkt, &cookiepkt)) {
+        || !PACKET_get_length_prefixed_1(pkt, &cookiepkt)) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_DTLS_PROCESS_HELLO_VERIFY, SSL_R_LENGTH_MISMATCH);
         goto f_err;
@@ -910,13 +1110,15 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
 {
     STACK_OF(SSL_CIPHER) *sk;
     const SSL_CIPHER *c;
-    PACKET session_id;
+    PACKET session_id, extpkt;
     size_t session_id_len;
     const unsigned char *cipherchars;
     int i, al = SSL_AD_INTERNAL_ERROR;
     unsigned int compression;
     unsigned int sversion;
+    unsigned int context;
     int protverr;
+    RAW_EXTENSION *extensions = NULL;
 #ifndef OPENSSL_NO_COMP
     SSL_COMP *comp;
 #endif
@@ -945,17 +1147,23 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
     s->hit = 0;
 
     /* Get the session-id. */
-    if (!PACKET_get_length_prefixed_1(pkt, &session_id)) {
-        al = SSL_AD_DECODE_ERROR;
-        SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
-        goto f_err;
-    }
-    session_id_len = PACKET_remaining(&session_id);
-    if (session_id_len > sizeof s->session->session_id
-        || session_id_len > SSL3_SESSION_ID_SIZE) {
-        al = SSL_AD_ILLEGAL_PARAMETER;
-        SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_SSL3_SESSION_ID_TOO_LONG);
-        goto f_err;
+    if (!SSL_IS_TLS13(s)) {
+        if (!PACKET_get_length_prefixed_1(pkt, &session_id)) {
+            al = SSL_AD_DECODE_ERROR;
+            SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
+            goto f_err;
+        }
+        session_id_len = PACKET_remaining(&session_id);
+        if (session_id_len > sizeof s->session->session_id
+            || session_id_len > SSL3_SESSION_ID_SIZE) {
+            al = SSL_AD_ILLEGAL_PARAMETER;
+            SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO,
+                   SSL_R_SSL3_SESSION_ID_TOO_LONG);
+            goto f_err;
+        }
+    } else {
+        PACKET_null_init(&session_id);
+        session_id_len = 0;
     }
 
     if (!PACKET_get_bytes(pkt, &cipherchars, TLS_CIPHER_LEN)) {
@@ -976,14 +1184,21 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
      * we can resume, and later peek at the next handshake message to see if the
      * server wants to resume.
      */
-    if (s->version >= TLS1_VERSION && s->tls_session_secret_cb &&
-        s->session->tlsext_tick) {
+    if (s->version >= TLS1_VERSION && !SSL_IS_TLS13(s)
+            && s->ext.session_secret_cb != NULL && s->session->ext.tick) {
         const SSL_CIPHER *pref_cipher = NULL;
-        s->session->master_key_length = sizeof(s->session->master_key);
-        if (s->tls_session_secret_cb(s, s->session->master_key,
-                                     &s->session->master_key_length,
+        /*
+         * s->session->master_key_length is a size_t, but this is an int for
+         * backwards compat reasons
+         */
+        int master_key_length;
+        master_key_length = sizeof(s->session->master_key);
+        if (s->ext.session_secret_cb(s, s->session->master_key,
+                                     &master_key_length,
                                      NULL, &pref_cipher,
-                                     s->tls_session_secret_cb_arg)) {
+                                     s->ext.session_secret_cb_arg)
+                 && master_key_length > 0) {
+            s->session->master_key_length = master_key_length;
             s->session->cipher = pref_cipher ?
                 pref_cipher : ssl_get_cipher_by_char(s, cipherchars);
         } else {
@@ -1023,8 +1238,9 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
         s->session->ssl_version = s->version;
         s->session->session_id_length = session_id_len;
         /* session_id_len could be 0 */
-        memcpy(s->session->session_id, PACKET_data(&session_id),
-               session_id_len);
+        if (session_id_len > 0)
+            memcpy(s->session->session_id, PACKET_data(&session_id),
+                   session_id_len);
     }
 
     /* Session version and negotiated protocol version should match */
@@ -1084,11 +1300,16 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
     s->s3->tmp.new_cipher = c;
     /* lets get the compression algorithm */
     /* COMPRESSION */
-    if (!PACKET_get_1(pkt, &compression)) {
-        SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
-        al = SSL_AD_DECODE_ERROR;
-        goto f_err;
+    if (!SSL_IS_TLS13(s)) {
+        if (!PACKET_get_1(pkt, &compression)) {
+            SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
+            al = SSL_AD_DECODE_ERROR;
+            goto f_err;
+        }
+    } else {
+        compression = 0;
     }
+
 #ifdef OPENSSL_NO_COMP
     if (compression != 0) {
         al = SSL_AD_ILLEGAL_PARAMETER;
@@ -1132,18 +1353,20 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
 #endif
 
     /* TLS extensions */
-    if (!ssl_parse_serverhello_tlsext(s, pkt)) {
-        SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_PARSE_TLSEXT);
-        goto err;
-    }
-
-    if (PACKET_remaining(pkt) != 0) {
-        /* wrong packet length */
+    if (PACKET_remaining(pkt) == 0) {
+        PACKET_null_init(&extpkt);
+    } else if (!PACKET_as_length_prefixed_2(pkt, &extpkt)) {
         al = SSL_AD_DECODE_ERROR;
-        SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_BAD_PACKET_LENGTH);
+        SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_BAD_LENGTH);
         goto f_err;
     }
 
+    context = SSL_IS_TLS13(s) ? EXT_TLS1_3_SERVER_HELLO
+                              : EXT_TLS1_2_SERVER_HELLO;
+    if (!tls_collect_extensions(s, &extpkt, context, &extensions, &al)
+            || !tls_parse_all_extensions(s, context, extensions, NULL, 0, &al))
+        goto f_err;
+
 #ifndef OPENSSL_NO_SCTP
     if (SSL_IS_DTLS(s) && s->hit) {
         unsigned char sctpauthkey[64];
@@ -1157,11 +1380,10 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
                sizeof(DTLS1_SCTP_AUTH_LABEL));
 
         if (SSL_export_keying_material(s, sctpauthkey,
-                                   sizeof(sctpauthkey),
-                                   labelbuffer,
-                                   sizeof(labelbuffer), NULL, 0,
-                                   0) <= 0)
-            goto err;
+                                       sizeof(sctpauthkey),
+                                       labelbuffer,
+                                       sizeof(labelbuffer), NULL, 0, 0) <= 0)
+            goto f_err;
 
         BIO_ctrl(SSL_get_wbio(s),
                  BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
@@ -1169,11 +1391,27 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
     }
 #endif
 
+    /*
+     * In TLSv1.3 we have some post-processing to change cipher state, otherwise
+     * we're done with this message
+     */
+    if (SSL_IS_TLS13(s)
+            && (!s->method->ssl3_enc->setup_key_block(s)
+                || !s->method->ssl3_enc->change_cipher_state(s,
+                    SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_WRITE)
+                || !s->method->ssl3_enc->change_cipher_state(s,
+                    SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_READ))) {
+        al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_CANNOT_CHANGE_CIPHER);
+        goto f_err;
+    }
+
+    OPENSSL_free(extensions);
     return MSG_PROCESS_CONTINUE_READING;
  f_err:
     ssl3_send_alert(s, SSL3_AL_FATAL, al);
- err:
     ossl_statem_set_error(s);
+    OPENSSL_free(extensions);
     return MSG_PROCESS_ERROR;
 }
 
@@ -1185,21 +1423,25 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
     const unsigned char *certstart, *certbytes;
     STACK_OF(X509) *sk = NULL;
     EVP_PKEY *pkey = NULL;
+    size_t chainidx;
+    unsigned int context = 0;
 
     if ((sk = sk_X509_new_null()) == NULL) {
         SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, ERR_R_MALLOC_FAILURE);
         goto err;
     }
 
-    if (!PACKET_get_net_3(pkt, &cert_list_len)
+    if ((SSL_IS_TLS13(s) && !PACKET_get_1(pkt, &context))
+            || context != 0
+            || !PACKET_get_net_3(pkt, &cert_list_len)
             || PACKET_remaining(pkt) != cert_list_len) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, SSL_R_LENGTH_MISMATCH);
         goto f_err;
     }
-    while (PACKET_remaining(pkt)) {
+    for (chainidx = 0; PACKET_remaining(pkt); chainidx++) {
         if (!PACKET_get_net_3(pkt, &cert_len)
-                || !PACKET_get_bytes(pkt, &certbytes, cert_len)) {
+            || !PACKET_get_bytes(pkt, &certbytes, cert_len)) {
             al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
                    SSL_R_CERT_LENGTH_MISMATCH);
@@ -1219,6 +1461,26 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
                    SSL_R_CERT_LENGTH_MISMATCH);
             goto f_err;
         }
+
+        if (SSL_IS_TLS13(s)) {
+            RAW_EXTENSION *rawexts = NULL;
+            PACKET extensions;
+
+            if (!PACKET_get_length_prefixed_2(pkt, &extensions)) {
+                al = SSL_AD_DECODE_ERROR;
+                SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, SSL_R_BAD_LENGTH);
+                goto f_err;
+            }
+            if (!tls_collect_extensions(s, &extensions, EXT_TLS1_3_CERTIFICATE,
+                                        &rawexts, &al)
+                    || !tls_parse_all_extensions(s, EXT_TLS1_3_CERTIFICATE,
+                                                 rawexts, x, chainidx, &al)) {
+                OPENSSL_free(rawexts);
+                goto f_err;
+            }
+            OPENSSL_free(rawexts);
+        }
+
         if (!sk_X509_push(sk, x)) {
             SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, ERR_R_MALLOC_FAILURE);
             goto err;
@@ -1227,7 +1489,21 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
     }
 
     i = ssl_verify_cert_chain(s, sk);
-    if ((s->verify_mode & SSL_VERIFY_PEER) && i <= 0) {
+    /*
+     * The documented interface is that SSL_VERIFY_PEER should be set in order
+     * for client side verification of the server certificate to take place.
+     * However, historically the code has only checked that *any* flag is set
+     * to cause server verification to take place. Use of the other flags makes
+     * no sense in client mode. An attempt to clean up the semantics was
+     * reverted because at least one application *only* set
+     * SSL_VERIFY_FAIL_IF_NO_PEER_CERT. Prior to the clean up this still caused
+     * server verification to take place, after the clean up it silently did
+     * nothing. SSL_CTX_set_verify()/SSL_set_verify() cannot validate the flags
+     * sent to them because they are void functions. Therefore, we now use the
+     * (less clean) historic behaviour of performing validation if any flag is
+     * set. The *documented* interface remains the same.
+     */
+    if (s->verify_mode != SSL_VERIFY_NONE && i <= 0) {
         al = ssl_verify_alarm_type(s->verify_result);
         SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
                SSL_R_CERTIFICATE_VERIFY_FAILED);
@@ -1272,9 +1548,9 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
 
     exp_idx = ssl_cipher_get_cert_index(s->s3->tmp.new_cipher);
     if (exp_idx >= 0 && i != exp_idx
-            && (exp_idx != SSL_PKEY_GOST_EC ||
-                (i != SSL_PKEY_GOST12_512 && i != SSL_PKEY_GOST12_256
-                 && i != SSL_PKEY_GOST01))) {
+        && (exp_idx != SSL_PKEY_GOST_EC ||
+            (i != SSL_PKEY_GOST12_512 && i != SSL_PKEY_GOST12_256
+             && i != SSL_PKEY_GOST01))) {
         x = NULL;
         al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
@@ -1287,8 +1563,18 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
     X509_up_ref(x);
     s->session->peer = x;
     s->session->verify_result = s->verify_result;
-
     x = NULL;
+
+    /* Save the current hash state for when we receive the CertificateVerify */
+    if (SSL_IS_TLS13(s)
+            && !ssl_handshake_hash(s, s->cert_verify_hash,
+                                   sizeof(s->cert_verify_hash),
+                                   &s->cert_verify_hash_len)) {
+        al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, ERR_R_INTERNAL_ERROR);
+        goto f_err;
+    }
+
     ret = MSG_PROCESS_CONTINUE_READING;
     goto done;
 
@@ -1302,287 +1588,347 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
     return ret;
 }
 
-MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
+static int tls_process_ske_psk_preamble(SSL *s, PACKET *pkt, int *al)
 {
-    EVP_MD_CTX *md_ctx;
-    int al, j;
-    long alg_k, alg_a;
-    EVP_PKEY *pkey = NULL;
-    const EVP_MD *md = NULL;
-#ifndef OPENSSL_NO_RSA
-    RSA *rsa = NULL;
-#endif
-#ifndef OPENSSL_NO_EC
-    EVP_PKEY_CTX *pctx = NULL;
+#ifndef OPENSSL_NO_PSK
+    PACKET psk_identity_hint;
+
+    /* PSK ciphersuites are preceded by an identity hint */
+
+    if (!PACKET_get_length_prefixed_2(pkt, &psk_identity_hint)) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE, SSL_R_LENGTH_MISMATCH);
+        return 0;
+    }
+
+    /*
+     * Store PSK identity hint for later use, hint is used in
+     * tls_construct_client_key_exchange.  Assume that the maximum length of
+     * a PSK identity hint can be as long as the maximum length of a PSK
+     * identity.
+     */
+    if (PACKET_remaining(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN) {
+        *al = SSL_AD_HANDSHAKE_FAILURE;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE, SSL_R_DATA_LENGTH_TOO_LONG);
+        return 0;
+    }
+
+    if (PACKET_remaining(&psk_identity_hint) == 0) {
+        OPENSSL_free(s->session->psk_identity_hint);
+        s->session->psk_identity_hint = NULL;
+    } else if (!PACKET_strndup(&psk_identity_hint,
+                               &s->session->psk_identity_hint)) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        return 0;
+    }
+
+    return 1;
+#else
+    SSLerr(SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE, ERR_R_INTERNAL_ERROR);
+    *al = SSL_AD_INTERNAL_ERROR;
+    return 0;
 #endif
-    PACKET save_param_start, signature;
+}
 
-    md_ctx = EVP_MD_CTX_new();
-    if (md_ctx == NULL) {
-        al = SSL_AD_INTERNAL_ERROR;
-        SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
-        goto f_err;
+static int tls_process_ske_srp(SSL *s, PACKET *pkt, EVP_PKEY **pkey, int *al)
+{
+#ifndef OPENSSL_NO_SRP
+    PACKET prime, generator, salt, server_pub;
+
+    if (!PACKET_get_length_prefixed_2(pkt, &prime)
+        || !PACKET_get_length_prefixed_2(pkt, &generator)
+        || !PACKET_get_length_prefixed_1(pkt, &salt)
+        || !PACKET_get_length_prefixed_2(pkt, &server_pub)) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_SRP, SSL_R_LENGTH_MISMATCH);
+        return 0;
     }
 
-    alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
+    /* TODO(size_t): Convert BN_bin2bn() calls */
+    if ((s->srp_ctx.N =
+         BN_bin2bn(PACKET_data(&prime),
+                   (int)PACKET_remaining(&prime), NULL)) == NULL
+        || (s->srp_ctx.g =
+            BN_bin2bn(PACKET_data(&generator),
+                      (int)PACKET_remaining(&generator), NULL)) == NULL
+        || (s->srp_ctx.s =
+            BN_bin2bn(PACKET_data(&salt),
+                      (int)PACKET_remaining(&salt), NULL)) == NULL
+        || (s->srp_ctx.B =
+            BN_bin2bn(PACKET_data(&server_pub),
+                      (int)PACKET_remaining(&server_pub), NULL)) == NULL) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_SRP, ERR_R_BN_LIB);
+        return 0;
+    }
 
-    save_param_start = *pkt;
+    if (!srp_verify_server_param(s, al)) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_SRP, SSL_R_BAD_SRP_PARAMETERS);
+        return 0;
+    }
 
-#if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
-    EVP_PKEY_free(s->s3->peer_tmp);
-    s->s3->peer_tmp = NULL;
+    /* We must check if there is a certificate */
+    if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aRSA | SSL_aDSS))
+        *pkey = X509_get0_pubkey(s->session->peer);
+
+    return 1;
+#else
+    SSLerr(SSL_F_TLS_PROCESS_SKE_SRP, ERR_R_INTERNAL_ERROR);
+    *al = SSL_AD_INTERNAL_ERROR;
+    return 0;
 #endif
+}
 
-    alg_a = s->s3->tmp.new_cipher->algorithm_auth;
+static int tls_process_ske_dhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey, int *al)
+{
+#ifndef OPENSSL_NO_DH
+    PACKET prime, generator, pub_key;
+    EVP_PKEY *peer_tmp = NULL;
 
-    al = SSL_AD_DECODE_ERROR;
+    DH *dh = NULL;
+    BIGNUM *p = NULL, *g = NULL, *bnpub_key = NULL;
 
-#ifndef OPENSSL_NO_PSK
-    /* PSK ciphersuites are preceded by an identity hint */
-    if (alg_k & SSL_PSK) {
-        PACKET psk_identity_hint;
-        if (!PACKET_get_length_prefixed_2(pkt, &psk_identity_hint)) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
-            goto f_err;
-        }
+    int check_bits = 0;
 
-        /*
-         * Store PSK identity hint for later use, hint is used in
-         * ssl3_send_client_key_exchange.  Assume that the maximum length of
-         * a PSK identity hint can be as long as the maximum length of a PSK
-         * identity.
-         */
-        if (PACKET_remaining(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN) {
-            al = SSL_AD_HANDSHAKE_FAILURE;
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_DATA_LENGTH_TOO_LONG);
-            goto f_err;
-        }
+    if (!PACKET_get_length_prefixed_2(pkt, &prime)
+        || !PACKET_get_length_prefixed_2(pkt, &generator)
+        || !PACKET_get_length_prefixed_2(pkt, &pub_key)) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, SSL_R_LENGTH_MISMATCH);
+        return 0;
+    }
 
-        if (PACKET_remaining(&psk_identity_hint) == 0) {
-            OPENSSL_free(s->session->psk_identity_hint);
-            s->session->psk_identity_hint = NULL;
-        } else if (!PACKET_strndup(&psk_identity_hint,
-                            &s->session->psk_identity_hint)) {
-            al = SSL_AD_INTERNAL_ERROR;
-            goto f_err;
-        }
+    peer_tmp = EVP_PKEY_new();
+    dh = DH_new();
+
+    if (peer_tmp == NULL || dh == NULL) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, ERR_R_MALLOC_FAILURE);
+        goto err;
     }
 
-    /* Nothing else to do for plain PSK or RSAPSK */
-    if (alg_k & (SSL_kPSK | SSL_kRSAPSK)) {
-    } else
-#endif                          /* !OPENSSL_NO_PSK */
-    /*
-     * Dummy "if" to ensure sane C code in the event of various OPENSSL_NO_*
-     * options
-     */
-    if (0) {
+    /* TODO(size_t): Convert these calls */
+    p = BN_bin2bn(PACKET_data(&prime), (int)PACKET_remaining(&prime), NULL);
+    g = BN_bin2bn(PACKET_data(&generator), (int)PACKET_remaining(&generator),
+                  NULL);
+    bnpub_key = BN_bin2bn(PACKET_data(&pub_key),
+                          (int)PACKET_remaining(&pub_key), NULL);
+    if (p == NULL || g == NULL || bnpub_key == NULL) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, ERR_R_BN_LIB);
+        goto err;
     }
-#ifndef OPENSSL_NO_SRP
-    else if (alg_k & SSL_kSRP) {
-        PACKET prime, generator, salt, server_pub;
-        if (!PACKET_get_length_prefixed_2(pkt, &prime)
-            || !PACKET_get_length_prefixed_2(pkt, &generator)
-            || !PACKET_get_length_prefixed_1(pkt, &salt)
-            || !PACKET_get_length_prefixed_2(pkt, &server_pub)) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
-            goto f_err;
-        }
 
-        if ((s->srp_ctx.N =
-             BN_bin2bn(PACKET_data(&prime),
-                       PACKET_remaining(&prime), NULL)) == NULL
-            || (s->srp_ctx.g =
-                BN_bin2bn(PACKET_data(&generator),
-                          PACKET_remaining(&generator), NULL)) == NULL
-            || (s->srp_ctx.s =
-                BN_bin2bn(PACKET_data(&salt),
-                          PACKET_remaining(&salt), NULL)) == NULL
-            || (s->srp_ctx.B =
-                BN_bin2bn(PACKET_data(&server_pub),
-                          PACKET_remaining(&server_pub), NULL)) == NULL) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_BN_LIB);
-            goto err;
-        }
+    /* test non-zero pupkey */
+    if (BN_is_zero(bnpub_key)) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, SSL_R_BAD_DH_VALUE);
+        goto err;
+    }
 
-        if (!srp_verify_server_param(s, &al)) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_BAD_SRP_PARAMETERS);
-            goto f_err;
-        }
+    if (!DH_set0_pqg(dh, p, NULL, g)) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, ERR_R_BN_LIB);
+        goto err;
+    }
+    p = g = NULL;
 
-/* We must check if there is a certificate */
-        if (alg_a & (SSL_aRSA|SSL_aDSS))
-            pkey = X509_get0_pubkey(s->session->peer);
+    if (DH_check_params(dh, &check_bits) == 0 || check_bits != 0) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, SSL_R_BAD_DH_VALUE);
+        goto err;
     }
-#endif                          /* !OPENSSL_NO_SRP */
-#ifndef OPENSSL_NO_DH
-    else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
-        PACKET prime, generator, pub_key;
-        EVP_PKEY *peer_tmp = NULL;
 
-        DH *dh = NULL;
-        BIGNUM *p = NULL, *g = NULL, *bnpub_key = NULL;
+    if (!DH_set0_key(dh, bnpub_key, NULL)) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, ERR_R_BN_LIB);
+        goto err;
+    }
+    bnpub_key = NULL;
 
-        if (!PACKET_get_length_prefixed_2(pkt, &prime)
-            || !PACKET_get_length_prefixed_2(pkt, &generator)
-            || !PACKET_get_length_prefixed_2(pkt, &pub_key)) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
-            goto f_err;
-        }
+    if (!ssl_security(s, SSL_SECOP_TMP_DH, DH_security_bits(dh), 0, dh)) {
+        *al = SSL_AD_HANDSHAKE_FAILURE;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, SSL_R_DH_KEY_TOO_SMALL);
+        goto err;
+    }
 
-        peer_tmp = EVP_PKEY_new();
-        dh = DH_new();
+    if (EVP_PKEY_assign_DH(peer_tmp, dh) == 0) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, ERR_R_EVP_LIB);
+        goto err;
+    }
 
-        if (peer_tmp == NULL || dh == NULL) {
-            al = SSL_AD_INTERNAL_ERROR;
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
-            goto dherr;
-        }
+    s->s3->peer_tmp = peer_tmp;
 
-        p = BN_bin2bn(PACKET_data(&prime), PACKET_remaining(&prime), NULL);
-        g = BN_bin2bn(PACKET_data(&generator), PACKET_remaining(&generator),
-                      NULL);
-        bnpub_key = BN_bin2bn(PACKET_data(&pub_key), PACKET_remaining(&pub_key),
-                              NULL);
-        if (p == NULL || g == NULL || bnpub_key == NULL) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_BN_LIB);
-            goto dherr;
-        }
+    /*
+     * FIXME: This makes assumptions about which ciphersuites come with
+     * public keys. We should have a less ad-hoc way of doing this
+     */
+    if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aRSA | SSL_aDSS))
+        *pkey = X509_get0_pubkey(s->session->peer);
+    /* else anonymous DH, so no certificate or pkey. */
 
-        if (BN_is_zero(p) || BN_is_zero(g) || BN_is_zero(bnpub_key)) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_BAD_DH_VALUE);
-            goto dherr;
-        }
+    return 1;
 
-        if (!DH_set0_pqg(dh, p, NULL, g)) {
-            al = SSL_AD_INTERNAL_ERROR;
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_BN_LIB);
-            goto dherr;
-        }
-        p = g = NULL;
+ err:
+    BN_free(p);
+    BN_free(g);
+    BN_free(bnpub_key);
+    DH_free(dh);
+    EVP_PKEY_free(peer_tmp);
 
-        if (!DH_set0_key(dh, bnpub_key, NULL)) {
-            al = SSL_AD_INTERNAL_ERROR;
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_BN_LIB);
-            goto dherr;
-        }
-        bnpub_key = NULL;
+    return 0;
+#else
+    SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, ERR_R_INTERNAL_ERROR);
+    *al = SSL_AD_INTERNAL_ERROR;
+    return 0;
+#endif
+}
 
-        if (!ssl_security(s, SSL_SECOP_TMP_DH, DH_security_bits(dh), 0, dh)) {
-            al = SSL_AD_HANDSHAKE_FAILURE;
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_DH_KEY_TOO_SMALL);
-            goto dherr;
-        }
+static int tls_process_ske_ecdhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey, int *al)
+{
+#ifndef OPENSSL_NO_EC
+    PACKET encoded_pt;
+    const unsigned char *ecparams;
+    int curve_nid;
+    unsigned int curve_flags;
+    EVP_PKEY_CTX *pctx = NULL;
 
-        if (EVP_PKEY_assign_DH(peer_tmp, dh) == 0) {
-            al = SSL_AD_INTERNAL_ERROR;
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_EVP_LIB);
-            goto dherr;
-        }
+    /*
+     * Extract elliptic curve parameters and the server's ephemeral ECDH
+     * public key. For now we only support named (not generic) curves and
+     * ECParameters in this case is just three bytes.
+     */
+    if (!PACKET_get_bytes(pkt, &ecparams, 3)) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, SSL_R_LENGTH_TOO_SHORT);
+        return 0;
+    }
+    /*
+     * Check curve is one of our preferences, if not server has sent an
+     * invalid curve. ECParameters is 3 bytes.
+     */
+    if (!tls1_check_curve(s, ecparams, 3)) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, SSL_R_WRONG_CURVE);
+        return 0;
+    }
 
-        s->s3->peer_tmp = peer_tmp;
+    curve_nid = tls1_ec_curve_id2nid(*(ecparams + 2), &curve_flags);
 
-        goto dhend;
- dherr:
-        BN_free(p);
-        BN_free(g);
-        BN_free(bnpub_key);
-        DH_free(dh);
-        EVP_PKEY_free(peer_tmp);
-        goto f_err;
- dhend:
-        /*
-         * FIXME: This makes assumptions about which ciphersuites come with
-         * public keys. We should have a less ad-hoc way of doing this
-         */
-        if (alg_a & (SSL_aRSA|SSL_aDSS))
-            pkey = X509_get0_pubkey(s->session->peer);
-        /* else anonymous DH, so no certificate or pkey. */
+    if (curve_nid == 0) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE,
+               SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
+        return 0;
     }
-#endif                          /* !OPENSSL_NO_DH */
 
-#ifndef OPENSSL_NO_EC
-    else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
-        PACKET encoded_pt;
-        const unsigned char *ecparams;
-        int curve_nid;
+    if ((curve_flags & TLS_CURVE_TYPE) == TLS_CURVE_CUSTOM) {
+        EVP_PKEY *key = EVP_PKEY_new();
 
-        /*
-         * Extract elliptic curve parameters and the server's ephemeral ECDH
-         * public key. For now we only support named (not generic) curves and
-         * ECParameters in this case is just three bytes.
-         */
-        if (!PACKET_get_bytes(pkt, &ecparams, 3)) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
-            goto f_err;
+        if (key == NULL || !EVP_PKEY_set_type(key, curve_nid)) {
+            *al = SSL_AD_INTERNAL_ERROR;
+            SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, ERR_R_EVP_LIB);
+            EVP_PKEY_free(key);
+            return 0;
         }
-        /*
-         * Check curve is one of our preferences, if not server has sent an
-         * invalid curve. ECParameters is 3 bytes.
-         */
-        if (!tls1_check_curve(s, ecparams, 3)) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_WRONG_CURVE);
-            goto f_err;
-        }
-
-        curve_nid = tls1_ec_curve_id2nid(*(ecparams + 2));
-        if (curve_nid  == 0) {
-            al = SSL_AD_INTERNAL_ERROR;
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE,
-                   SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
-            goto f_err;
-        }
-
+        s->s3->peer_tmp = key;
+    } else {
         /* Set up EVP_PKEY with named curve as parameters */
         pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL);
         if (pctx == NULL
             || EVP_PKEY_paramgen_init(pctx) <= 0
             || EVP_PKEY_CTX_set_ec_paramgen_curve_nid(pctx, curve_nid) <= 0
             || EVP_PKEY_paramgen(pctx, &s->s3->peer_tmp) <= 0) {
-            al = SSL_AD_INTERNAL_ERROR;
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_EVP_LIB);
-            goto f_err;
+            *al = SSL_AD_INTERNAL_ERROR;
+            SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, ERR_R_EVP_LIB);
+            EVP_PKEY_CTX_free(pctx);
+            return 0;
         }
         EVP_PKEY_CTX_free(pctx);
         pctx = NULL;
+    }
 
-        if (!PACKET_get_length_prefixed_1(pkt, &encoded_pt)) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
-            goto f_err;
-        }
+    if (!PACKET_get_length_prefixed_1(pkt, &encoded_pt)) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, SSL_R_LENGTH_MISMATCH);
+        return 0;
+    }
 
-        if (EC_KEY_oct2key(EVP_PKEY_get0_EC_KEY(s->s3->peer_tmp),
-                           PACKET_data(&encoded_pt),
-                           PACKET_remaining(&encoded_pt), NULL) == 0) {
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_BAD_ECPOINT);
-            goto f_err;
-        }
+    if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
+                                        PACKET_data(&encoded_pt),
+                                        PACKET_remaining(&encoded_pt))) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, SSL_R_BAD_ECPOINT);
+        return 0;
+    }
 
-        /*
-         * The ECC/TLS specification does not mention the use of DSA to sign
-         * ECParameters in the server key exchange message. We do support RSA
-         * and ECDSA.
-         */
-        if (0) ;
-# ifndef OPENSSL_NO_RSA
-        else if (alg_a & SSL_aRSA)
-            pkey = X509_get0_pubkey(s->session->peer);
-# endif
-# ifndef OPENSSL_NO_EC
-        else if (alg_a & SSL_aECDSA)
-            pkey = X509_get0_pubkey(s->session->peer);
-# endif
-        /* else anonymous ECDH, so no certificate or pkey. */
+    /*
+     * The ECC/TLS specification does not mention the use of DSA to sign
+     * ECParameters in the server key exchange message. We do support RSA
+     * and ECDSA.
+     */
+    if (s->s3->tmp.new_cipher->algorithm_auth & SSL_aECDSA)
+        *pkey = X509_get0_pubkey(s->session->peer);
+    else if (s->s3->tmp.new_cipher->algorithm_auth & SSL_aRSA)
+        *pkey = X509_get0_pubkey(s->session->peer);
+    /* else anonymous ECDH, so no certificate or pkey. */
+
+    return 1;
+#else
+    SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, ERR_R_INTERNAL_ERROR);
+    *al = SSL_AD_INTERNAL_ERROR;
+    return 0;
+#endif
+}
+
+MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
+{
+    int al = -1, ispss = 0;
+    long alg_k;
+    EVP_PKEY *pkey = NULL;
+    EVP_MD_CTX *md_ctx = NULL;
+    EVP_PKEY_CTX *pctx = NULL;
+    PACKET save_param_start, signature;
+
+    alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
+
+    save_param_start = *pkt;
+
+#if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
+    EVP_PKEY_free(s->s3->peer_tmp);
+    s->s3->peer_tmp = NULL;
+#endif
+
+    if (alg_k & SSL_PSK) {
+        if (!tls_process_ske_psk_preamble(s, pkt, &al))
+            goto err;
+    }
+
+    /* Nothing else to do for plain PSK or RSAPSK */
+    if (alg_k & (SSL_kPSK | SSL_kRSAPSK)) {
+    } else if (alg_k & SSL_kSRP) {
+        if (!tls_process_ske_srp(s, pkt, &pkey, &al))
+            goto err;
+    } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
+        if (!tls_process_ske_dhe(s, pkt, &pkey, &al))
+            goto err;
+    } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
+        if (!tls_process_ske_ecdhe(s, pkt, &pkey, &al))
+            goto err;
     } else if (alg_k) {
         al = SSL_AD_UNEXPECTED_MESSAGE;
         SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_UNEXPECTED_MESSAGE);
-        goto f_err;
+        goto err;
     }
-#endif                          /* !OPENSSL_NO_EC */
 
     /* if it was signed, check the signature */
     if (pkey != NULL) {
         PACKET params;
+        int maxsig;
+        const EVP_MD *md = NULL;
+
         /*
          * |pkt| now points to the beginning of the signature, so the difference
          * equals the length of the parameters.
@@ -1592,22 +1938,27 @@ MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
                                    PACKET_remaining(pkt))) {
             al = SSL_AD_INTERNAL_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
-            goto f_err;
+            goto err;
         }
 
         if (SSL_USE_SIGALGS(s)) {
-            const unsigned char *sigalgs;
+            unsigned int sigalg;
             int rv;
-            if (!PACKET_get_bytes(pkt, &sigalgs, 2)) {
+
+            if (!PACKET_get_net_2(pkt, &sigalg)) {
+                al = SSL_AD_DECODE_ERROR;
                 SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
-                goto f_err;
+                goto err;
             }
-            rv = tls12_check_peer_sigalg(&md, s, sigalgs, pkey);
-            if (rv == -1)
+            rv = tls12_check_peer_sigalg(&md, s, sigalg, pkey);
+            if (rv == -1) {
+                al = SSL_AD_INTERNAL_ERROR;
+                goto err;
+            } else if (rv == 0) {
+                al = SSL_AD_DECODE_ERROR;
                 goto err;
-            else if (rv == 0) {
-                goto f_err;
             }
+            ispss = SIGID_IS_PSS(sigalg);
 #ifdef SSL_DEBUG
             fprintf(stderr, "USING TLSv1.2 HASH %s\n", EVP_MD_name(md));
 #endif
@@ -1619,69 +1970,96 @@ MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
 
         if (!PACKET_get_length_prefixed_2(pkt, &signature)
             || PACKET_remaining(pkt) != 0) {
+            al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
-            goto f_err;
+            goto err;
         }
-        j = EVP_PKEY_size(pkey);
-        if (j < 0) {
+        maxsig = EVP_PKEY_size(pkey);
+        if (maxsig < 0) {
+            al = SSL_AD_INTERNAL_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
-            goto f_err;
+            goto err;
         }
 
         /*
          * Check signature length
          */
-        if (PACKET_remaining(&signature) > (size_t)j) {
+        if (PACKET_remaining(&signature) > (size_t)maxsig) {
             /* wrong packet length */
-            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_WRONG_SIGNATURE_LENGTH);
-            goto f_err;
+            al = SSL_AD_DECODE_ERROR;
+            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                   SSL_R_WRONG_SIGNATURE_LENGTH);
+            goto err;
         }
-        if (EVP_VerifyInit_ex(md_ctx, md, NULL) <= 0
-                || EVP_VerifyUpdate(md_ctx, &(s->s3->client_random[0]),
-                                    SSL3_RANDOM_SIZE) <= 0
-                || EVP_VerifyUpdate(md_ctx, &(s->s3->server_random[0]),
-                                    SSL3_RANDOM_SIZE) <= 0
-                || EVP_VerifyUpdate(md_ctx, PACKET_data(&params),
-                                    PACKET_remaining(&params)) <= 0) {
+
+        md_ctx = EVP_MD_CTX_new();
+        if (md_ctx == NULL) {
+            al = SSL_AD_INTERNAL_ERROR;
+            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+
+        if (EVP_DigestVerifyInit(md_ctx, &pctx, md, NULL, pkey) <= 0) {
             al = SSL_AD_INTERNAL_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_EVP_LIB);
-            goto f_err;
+            goto err;
+        }
+        if (ispss) {
+            if (EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) <= 0
+                       /* -1 here means set saltlen to the digest len */
+                    || EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1) <= 0) {
+                al = SSL_AD_INTERNAL_ERROR;
+                SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_EVP_LIB);
+                goto err;
+            }
         }
-        if (EVP_VerifyFinal(md_ctx, PACKET_data(&signature),
-                            PACKET_remaining(&signature), pkey) <= 0) {
+        if (EVP_DigestVerifyUpdate(md_ctx, &(s->s3->client_random[0]),
+                                   SSL3_RANDOM_SIZE) <= 0
+                || EVP_DigestVerifyUpdate(md_ctx, &(s->s3->server_random[0]),
+                                          SSL3_RANDOM_SIZE) <= 0
+                || EVP_DigestVerifyUpdate(md_ctx, PACKET_data(&params),
+                                          PACKET_remaining(&params)) <= 0) {
+            al = SSL_AD_INTERNAL_ERROR;
+            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_EVP_LIB);
+            goto err;
+        }
+        if (EVP_DigestVerifyFinal(md_ctx, PACKET_data(&signature),
+                                  PACKET_remaining(&signature)) <= 0) {
             /* bad signature */
             al = SSL_AD_DECRYPT_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_BAD_SIGNATURE);
-            goto f_err;
+            goto err;
         }
+        EVP_MD_CTX_free(md_ctx);
+        md_ctx = NULL;
     } else {
         /* aNULL, aSRP or PSK do not need public keys */
-        if (!(alg_a & (SSL_aNULL | SSL_aSRP)) && !(alg_k & SSL_PSK)) {
+        if (!(s->s3->tmp.new_cipher->algorithm_auth & (SSL_aNULL | SSL_aSRP))
+            && !(alg_k & SSL_PSK)) {
             /* Might be wrong key type, check it */
-            if (ssl3_check_cert_and_algorithm(s))
+            if (ssl3_check_cert_and_algorithm(s)) {
                 /* Otherwise this shouldn't happen */
+                al = SSL_AD_INTERNAL_ERROR;
                 SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
+            } else {
+                al = SSL_AD_DECODE_ERROR;
+            }
             goto err;
         }
         /* still data left over */
         if (PACKET_remaining(pkt) != 0) {
+            al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_EXTRA_DATA_IN_MESSAGE);
-            goto f_err;
+            goto err;
         }
     }
-    EVP_MD_CTX_free(md_ctx);
+
     return MSG_PROCESS_CONTINUE_READING;
- f_err:
-    ssl3_send_alert(s, SSL3_AL_FATAL, al);
  err:
-#ifndef OPENSSL_NO_RSA
-    RSA_free(rsa);
-#endif
-#ifndef OPENSSL_NO_EC
-    EVP_PKEY_CTX_free(pctx);
-#endif
-    EVP_MD_CTX_free(md_ctx);
+    if (al != -1)
+        ssl3_send_alert(s, SSL3_AL_FATAL, al);
     ossl_statem_set_error(s);
+    EVP_MD_CTX_free(md_ctx);
     return MSG_PROCESS_ERROR;
 }
 
@@ -1701,7 +2079,7 @@ MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
 
     /* get the certificate types */
     if (!PACKET_get_1(pkt, &ctype_num)
-            || !PACKET_get_bytes(pkt, &data, ctype_num)) {
+        || !PACKET_get_bytes(pkt, &data, ctype_num)) {
         ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
         SSLerr(SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST, SSL_R_LENGTH_MISMATCH);
         goto err;
@@ -1716,15 +2094,16 @@ MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
             goto err;
         }
         memcpy(s->cert->ctypes, data, ctype_num);
-        s->cert->ctype_num = (size_t)ctype_num;
+        s->cert->ctype_num = ctype_num;
         ctype_num = SSL3_CT_NUMBER;
     }
     for (i = 0; i < ctype_num; i++)
         s->s3->tmp.ctype[i] = data[i];
 
     if (SSL_USE_SIGALGS(s)) {
-        if (!PACKET_get_net_2(pkt, &list_len)
-                || !PACKET_get_bytes(pkt, &data, list_len)) {
+        PACKET sigalgs;
+
+        if (!PACKET_get_length_prefixed_2(pkt, &sigalgs)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
             SSLerr(SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
                    SSL_R_LENGTH_MISMATCH);
@@ -1736,7 +2115,7 @@ MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
             s->s3->tmp.md[i] = NULL;
             s->s3->tmp.valid_flags[i] = 0;
         }
-        if ((list_len & 1) || !tls1_save_sigalgs(s, data, list_len)) {
+        if (!tls1_save_sigalgs(s, &sigalgs)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
             SSLerr(SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
                    SSL_R_SIGNATURE_ALGORITHMS_ERROR);
@@ -1753,7 +2132,7 @@ MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
 
     /* get the CA RDNs */
     if (!PACKET_get_net_2(pkt, &list_len)
-            || PACKET_remaining(pkt) != list_len) {
+        || PACKET_remaining(pkt) != list_len) {
         ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
         SSLerr(SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST, SSL_R_LENGTH_MISMATCH);
         goto err;
@@ -1761,7 +2140,7 @@ MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
 
     while (PACKET_remaining(pkt)) {
         if (!PACKET_get_net_2(pkt, &name_len)
-                || !PACKET_get_bytes(pkt, &namebytes, name_len)) {
+            || !PACKET_get_bytes(pkt, &namebytes, name_len)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
             SSLerr(SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
                    SSL_R_LENGTH_MISMATCH);
@@ -1816,20 +2195,30 @@ MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
 {
     int al;
     unsigned int ticklen;
-    unsigned long ticket_lifetime_hint;
+    unsigned long ticket_lifetime_hint, add_age;
+    unsigned int sess_len;
+    RAW_EXTENSION *exts = NULL;
 
     if (!PACKET_get_net_4(pkt, &ticket_lifetime_hint)
-            || !PACKET_get_net_2(pkt, &ticklen)
-            || PACKET_remaining(pkt) != ticklen) {
+        || (SSL_IS_TLS13(s) && !PACKET_get_net_4(pkt, &add_age))
+        || !PACKET_get_net_2(pkt, &ticklen)
+        || (!SSL_IS_TLS13(s) && PACKET_remaining(pkt) != ticklen)
+        || (SSL_IS_TLS13(s) && (ticklen == 0
+                                || PACKET_remaining(pkt) < ticklen))) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_NEW_SESSION_TICKET, SSL_R_LENGTH_MISMATCH);
         goto f_err;
     }
 
-    /* Server is allowed to change its mind and send an empty ticket. */
+    /*
+     * Server is allowed to change its mind (in <=TLSv1.2) and send an empty
+     * ticket. We already checked this TLSv1.3 case above, so it should never
+     * be 0 here in that instance
+     */
     if (ticklen == 0)
         return MSG_PROCESS_CONTINUE_READING;
 
+    /* TODO(TLS1.3): Is this a suitable test for TLS1.3? */
     if (s->session->session_id_length > 0) {
         int i = s->session_ctx->session_cache_mode;
         SSL_SESSION *new_sess;
@@ -1839,16 +2228,9 @@ MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
          */
         if (i & SSL_SESS_CACHE_CLIENT) {
             /*
-             * Remove the old session from the cache
+             * Remove the old session from the cache. We carry on if this fails
              */
-            if (i & SSL_SESS_CACHE_NO_INTERNAL_STORE) {
-                if (s->session_ctx->remove_session_cb != NULL)
-                    s->session_ctx->remove_session_cb(s->session_ctx,
-                                                      s->session);
-            } else {
-                /* We carry on if this fails */
-                SSL_CTX_remove_session(s->session_ctx, s->session);
-            }
+            SSL_CTX_remove_session(s->session_ctx, s->session);
         }
 
         if ((new_sess = ssl_session_dup(s->session, 0)) == 0) {
@@ -1861,22 +2243,38 @@ MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
         s->session = new_sess;
     }
 
-    OPENSSL_free(s->session->tlsext_tick);
-    s->session->tlsext_ticklen = 0;
+    OPENSSL_free(s->session->ext.tick);
+    s->session->ext.tick = NULL;
+    s->session->ext.ticklen = 0;
 
-    s->session->tlsext_tick = OPENSSL_malloc(ticklen);
-    if (s->session->tlsext_tick == NULL) {
+    s->session->ext.tick = OPENSSL_malloc(ticklen);
+    if (s->session->ext.tick == NULL) {
         SSLerr(SSL_F_TLS_PROCESS_NEW_SESSION_TICKET, ERR_R_MALLOC_FAILURE);
         goto err;
     }
-    if (!PACKET_copy_bytes(pkt, s->session->tlsext_tick, ticklen)) {
+    if (!PACKET_copy_bytes(pkt, s->session->ext.tick, ticklen)) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_NEW_SESSION_TICKET, SSL_R_LENGTH_MISMATCH);
         goto f_err;
     }
 
-    s->session->tlsext_tick_lifetime_hint = ticket_lifetime_hint;
-    s->session->tlsext_ticklen = ticklen;
+    s->session->ext.tick_lifetime_hint = ticket_lifetime_hint;
+    s->session->ext.ticklen = ticklen;
+
+    if (SSL_IS_TLS13(s)) {
+        PACKET extpkt;
+
+        if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
+                || !tls_collect_extensions(s, &extpkt,
+                                           EXT_TLS1_3_NEW_SESSION_TICKET,
+                                           &exts, &al)
+                || !tls_parse_all_extensions(s, EXT_TLS1_3_NEW_SESSION_TICKET,
+                                             exts, NULL, 0, &al)) {
+            SSLerr(SSL_F_TLS_PROCESS_NEW_SESSION_TICKET, SSL_R_BAD_EXTENSION);
+            goto f_err;
+        }
+    }
+
     /*
      * There are two ways to detect a resumed ticket session. One is to set
      * an appropriate session ID and then the server must return a match in
@@ -1888,12 +2286,24 @@ MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
      * elsewhere in OpenSSL. The session ID is set to the SHA256 (or SHA1 is
      * SHA256 is disabled) hash of the ticket.
      */
-    if (!EVP_Digest(s->session->tlsext_tick, ticklen,
-                    s->session->session_id, &s->session->session_id_length,
+    /*
+     * TODO(size_t): we use sess_len here because EVP_Digest expects an int
+     * but s->session->session_id_length is a size_t
+     */
+    if (!EVP_Digest(s->session->ext.tick, ticklen,
+                    s->session->session_id, &sess_len,
                     EVP_sha256(), NULL)) {
         SSLerr(SSL_F_TLS_PROCESS_NEW_SESSION_TICKET, ERR_R_EVP_LIB);
         goto err;
     }
+    s->session->session_id_length = sess_len;
+
+    /* This is a standalone message in TLSv1.3, so there is no more to read */
+    if (SSL_IS_TLS13(s)) {
+        ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
+        return MSG_PROCESS_FINISHED_READING;
+    }
+
     return MSG_PROCESS_CONTINUE_READING;
  f_err:
     ssl3_send_alert(s, SSL3_AL_FATAL, al);
@@ -1902,118 +2312,152 @@ MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
     return MSG_PROCESS_ERROR;
 }
 
-MSG_PROCESS_RETURN tls_process_cert_status(SSL *s, PACKET *pkt)
+/*
+ * In TLSv1.3 this is called from the extensions code, otherwise it is used to
+ * parse a separate message. Returns 1 on success or 0 on failure. On failure
+ * |*al| is populated with a suitable alert code.
+ */
+int tls_process_cert_status_body(SSL *s, PACKET *pkt, int *al)
 {
-    int al;
-    unsigned long resplen;
+    size_t resplen;
     unsigned int type;
 
-    if (!PACKET_get_1(pkt, &type)
-            || type != TLSEXT_STATUSTYPE_ocsp) {
-        al = SSL_AD_DECODE_ERROR;
-        SSLerr(SSL_F_TLS_PROCESS_CERT_STATUS, SSL_R_UNSUPPORTED_STATUS_TYPE);
-        goto f_err;
+    if (!PACKET_get_1(pkt, &type)
+        || type != TLSEXT_STATUSTYPE_ocsp) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
+               SSL_R_UNSUPPORTED_STATUS_TYPE);
+        return 0;
     }
-    if (!PACKET_get_net_3(pkt, &resplen)
-            || PACKET_remaining(pkt) != resplen) {
-        al = SSL_AD_DECODE_ERROR;
-        SSLerr(SSL_F_TLS_PROCESS_CERT_STATUS, SSL_R_LENGTH_MISMATCH);
-        goto f_err;
+    if (!PACKET_get_net_3_len(pkt, &resplen)
+        || PACKET_remaining(pkt) != resplen) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_CERT_STATUS_BODY, SSL_R_LENGTH_MISMATCH);
+        return 0;
     }
-    s->tlsext_ocsp_resp = OPENSSL_malloc(resplen);
-    if (s->tlsext_ocsp_resp == NULL) {
-        al = SSL_AD_INTERNAL_ERROR;
-        SSLerr(SSL_F_TLS_PROCESS_CERT_STATUS, ERR_R_MALLOC_FAILURE);
-        goto f_err;
+    s->ext.ocsp.resp = OPENSSL_malloc(resplen);
+    if (s->ext.ocsp.resp == NULL) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_CERT_STATUS_BODY, ERR_R_MALLOC_FAILURE);
+        return 0;
     }
-    if (!PACKET_copy_bytes(pkt, s->tlsext_ocsp_resp, resplen)) {
-        al = SSL_AD_DECODE_ERROR;
-        SSLerr(SSL_F_TLS_PROCESS_CERT_STATUS, SSL_R_LENGTH_MISMATCH);
-        goto f_err;
+    if (!PACKET_copy_bytes(pkt, s->ext.ocsp.resp, resplen)) {
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_CERT_STATUS_BODY, SSL_R_LENGTH_MISMATCH);
+        return 0;
     }
-    s->tlsext_ocsp_resplen = resplen;
-    return MSG_PROCESS_CONTINUE_READING;
- f_err:
-    ssl3_send_alert(s, SSL3_AL_FATAL, al);
-    ossl_statem_set_error(s);
-    return MSG_PROCESS_ERROR;
+    s->ext.ocsp.resp_len = resplen;
+
+    return 1;
 }
 
-MSG_PROCESS_RETURN tls_process_server_done(SSL *s, PACKET *pkt)
+
+MSG_PROCESS_RETURN tls_process_cert_status(SSL *s, PACKET *pkt)
 {
-    if (PACKET_remaining(pkt) > 0) {
-        /* should contain no data */
-        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
-        SSLerr(SSL_F_TLS_PROCESS_SERVER_DONE, SSL_R_LENGTH_MISMATCH);
+    int al;
+
+    if (!tls_process_cert_status_body(s, pkt, &al)) {
+        ssl3_send_alert(s, SSL3_AL_FATAL, al);
         ossl_statem_set_error(s);
         return MSG_PROCESS_ERROR;
     }
 
-#ifndef OPENSSL_NO_SRP
-    if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
-        if (SRP_Calc_A_param(s) <= 0) {
-            SSLerr(SSL_F_TLS_PROCESS_SERVER_DONE, SSL_R_SRP_A_CALC);
-            ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
-            ossl_statem_set_error(s);
-            return MSG_PROCESS_ERROR;
-        }
-    }
-#endif
+    return MSG_PROCESS_CONTINUE_READING;
+}
 
+/*
+ * Perform miscellaneous checks and processing after we have received the
+ * server's initial flight. In TLS1.3 this is after the Server Finished message.
+ * In <=TLS1.2 this is after the ServerDone message. Returns 1 on success or 0
+ * on failure.
+ */
+int tls_process_initial_server_flight(SSL *s, int *al)
+{
     /*
      * at this point we check that we have the required stuff from
      * the server
      */
     if (!ssl3_check_cert_and_algorithm(s)) {
-        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
-        ossl_statem_set_error(s);
-        return MSG_PROCESS_ERROR;
+        *al = SSL_AD_HANDSHAKE_FAILURE;
+        return 0;
     }
 
     /*
-     * Call the ocsp status callback if needed. The |tlsext_ocsp_resp| and
-     * |tlsext_ocsp_resplen| values will be set if we actually received a status
+     * Call the ocsp status callback if needed. The |ext.ocsp.resp| and
+     * |ext.ocsp.resp_len| values will be set if we actually received a status
      * message, or NULL and -1 otherwise
      */
-    if (s->tlsext_status_type != -1 && s->ctx->tlsext_status_cb != NULL) {
-        int ret;
-        ret = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
+    if (s->ext.status_type != TLSEXT_STATUSTYPE_nothing
+            && s->ctx->ext.status_cb != NULL) {
+        int ret = s->ctx->ext.status_cb(s, s->ctx->ext.status_arg);
+
         if (ret == 0) {
-            ssl3_send_alert(s, SSL3_AL_FATAL,
-                            SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE);
-            SSLerr(SSL_F_TLS_PROCESS_SERVER_DONE,
+            *al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
+            SSLerr(SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
                    SSL_R_INVALID_STATUS_RESPONSE);
-            return MSG_PROCESS_ERROR;
+            return 0;
         }
         if (ret < 0) {
-            ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
-            SSLerr(SSL_F_TLS_PROCESS_SERVER_DONE, ERR_R_MALLOC_FAILURE);
-            return MSG_PROCESS_ERROR;
+            *al = SSL_AD_INTERNAL_ERROR;
+            SSLerr(SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
+                   ERR_R_MALLOC_FAILURE);
+            return 0;
         }
     }
-
 #ifndef OPENSSL_NO_CT
     if (s->ct_validation_callback != NULL) {
         /* Note we validate the SCTs whether or not we abort on error */
         if (!ssl_validate_ct(s) && (s->verify_mode & SSL_VERIFY_PEER)) {
-            ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
-            return MSG_PROCESS_ERROR;
+            *al = SSL_AD_HANDSHAKE_FAILURE;
+            return 0;
+        }
+    }
+#endif
+
+    return 1;
+}
+
+MSG_PROCESS_RETURN tls_process_server_done(SSL *s, PACKET *pkt)
+{
+    int al = SSL_AD_INTERNAL_ERROR;
+
+    if (PACKET_remaining(pkt) > 0) {
+        /* should contain no data */
+        al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_SERVER_DONE, SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+#ifndef OPENSSL_NO_SRP
+    if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
+        if (SRP_Calc_A_param(s) <= 0) {
+            SSLerr(SSL_F_TLS_PROCESS_SERVER_DONE, SSL_R_SRP_A_CALC);
+            goto err;
         }
     }
 #endif
 
+    /*
+     * Error queue messages are generated directly by this function
+     */
+    if (!tls_process_initial_server_flight(s, &al))
+        goto err;
+
 #ifndef OPENSSL_NO_SCTP
     /* Only applies to renegotiation */
     if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))
-            && s->renegotiate != 0)
+        && s->renegotiate != 0)
         return MSG_PROCESS_CONTINUE_PROCESSING;
     else
 #endif
         return MSG_PROCESS_FINISHED_READING;
+
+ err:
+    ssl3_send_alert(s, SSL3_AL_FATAL, al);
+    ossl_statem_set_error(s);
+    return MSG_PROCESS_ERROR;
 }
 
-static int tls_construct_cke_psk_preamble(SSL *s, unsigned char **p,
-                                          size_t *pskhdrlen, int *al)
+static int tls_construct_cke_psk_preamble(SSL *s, WPACKET *pkt, int *al)
 {
 #ifndef OPENSSL_NO_PSK
     int ret = 0;
@@ -2074,10 +2518,12 @@ static int tls_construct_cke_psk_preamble(SSL *s, unsigned char **p,
     OPENSSL_free(s->session->psk_identity);
     s->session->psk_identity = tmpidentity;
     tmpidentity = NULL;
-    s2n(identitylen, *p);
-    memcpy(*p, identity, identitylen);
-    *pskhdrlen = 2 + identitylen;
-    *p += identitylen;
+
+    if (!WPACKET_sub_memcpy_u16(pkt, identity, identitylen))  {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE, ERR_R_INTERNAL_ERROR);
+        *al = SSL_AD_INTERNAL_ERROR;
+        goto err;
+    }
 
     ret = 1;
 
@@ -2095,10 +2541,10 @@ static int tls_construct_cke_psk_preamble(SSL *s, unsigned char **p,
 #endif
 }
 
-static int tls_construct_cke_rsa(SSL *s, unsigned char **p, int *len, int *al)
+static int tls_construct_cke_rsa(SSL *s, WPACKET *pkt, int *al)
 {
 #ifndef OPENSSL_NO_RSA
-    unsigned char *q;
+    unsigned char *encdata = NULL;
     EVP_PKEY *pkey = NULL;
     EVP_PKEY_CTX *pctx = NULL;
     size_t enclen;
@@ -2129,25 +2575,27 @@ static int tls_construct_cke_rsa(SSL *s, unsigned char **p, int *len, int *al)
 
     pms[0] = s->client_version >> 8;
     pms[1] = s->client_version & 0xff;
-    if (RAND_bytes(pms + 2, pmslen - 2) <= 0) {
+    /* TODO(size_t): Convert this function */
+    if (RAND_bytes(pms + 2, (int)(pmslen - 2)) <= 0) {
         goto err;
     }
 
-    q = *p;
     /* Fix buf for TLS and beyond */
-    if (s->version > SSL3_VERSION)
-        *p += 2;
+    if (s->version > SSL3_VERSION && !WPACKET_start_sub_packet_u16(pkt)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
     pctx = EVP_PKEY_CTX_new(pkey, NULL);
     if (pctx == NULL || EVP_PKEY_encrypt_init(pctx) <= 0
         || EVP_PKEY_encrypt(pctx, NULL, &enclen, pms, pmslen) <= 0) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_EVP_LIB);
         goto err;
     }
-    if (EVP_PKEY_encrypt(pctx, *p, &enclen, pms, pmslen) <= 0) {
+    if (!WPACKET_allocate_bytes(pkt, enclen, &encdata)
+            || EVP_PKEY_encrypt(pctx, encdata, &enclen, pms, pmslen) <= 0) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, SSL_R_BAD_RSA_ENCRYPT);
         goto err;
     }
-    *len = enclen;
     EVP_PKEY_CTX_free(pctx);
     pctx = NULL;
 # ifdef PKCS1_CHECK
@@ -2158,14 +2606,18 @@ static int tls_construct_cke_rsa(SSL *s, unsigned char **p, int *len, int *al)
 # endif
 
     /* Fix buf for TLS and beyond */
-    if (s->version > SSL3_VERSION) {
-        s2n(*len, q);
-        *len += 2;
+    if (s->version > SSL3_VERSION && !WPACKET_close(pkt)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_RSA, ERR_R_INTERNAL_ERROR);
+        goto err;
     }
 
     s->s3->tmp.pms = pms;
     s->s3->tmp.pmslen = pmslen;
 
+    /* Log the premaster secret, if logging is enabled. */
+    if (!ssl_log_rsa_client_key_exchange(s, encdata, enclen, pms, pmslen))
+        goto err;
+
     return 1;
  err:
     OPENSSL_clear_free(pms, pmslen);
@@ -2179,92 +2631,87 @@ static int tls_construct_cke_rsa(SSL *s, unsigned char **p, int *len, int *al)
 #endif
 }
 
-static int tls_construct_cke_dhe(SSL *s, unsigned char **p, int *len, int *al)
+static int tls_construct_cke_dhe(SSL *s, WPACKET *pkt, int *al)
 {
 #ifndef OPENSSL_NO_DH
     DH *dh_clnt = NULL;
     const BIGNUM *pub_key;
     EVP_PKEY *ckey = NULL, *skey = NULL;
+    unsigned char *keybytes = NULL;
 
     skey = s->s3->peer_tmp;
-    if (skey == NULL) {
-        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_DHE, ERR_R_INTERNAL_ERROR);
-        return 0;
-    }
-    ckey = ssl_generate_pkey(skey, NID_undef);
+    if (skey == NULL)
+        goto err;
+
+    ckey = ssl_generate_pkey(skey);
+    if (ckey == NULL)
+        goto err;
+
     dh_clnt = EVP_PKEY_get0_DH(ckey);
 
-    if (dh_clnt == NULL || ssl_derive(s, ckey, skey) == 0) {
-        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_DHE, ERR_R_INTERNAL_ERROR);
-        EVP_PKEY_free(ckey);
-        return 0;
-    }
+    if (dh_clnt == NULL || ssl_derive(s, ckey, skey, 0) == 0)
+        goto err;
 
     /* send off the data */
     DH_get0_key(dh_clnt, &pub_key, NULL);
-    *len = BN_num_bytes(pub_key);
-    s2n(*len, *p);
-    BN_bn2bin(pub_key, *p);
-    *len += 2;
+    if (!WPACKET_sub_allocate_bytes_u16(pkt, BN_num_bytes(pub_key), &keybytes))
+        goto err;
+
+    BN_bn2bin(pub_key, keybytes);
     EVP_PKEY_free(ckey);
 
     return 1;
-#else
+ err:
+    EVP_PKEY_free(ckey);
+#endif
     SSLerr(SSL_F_TLS_CONSTRUCT_CKE_DHE, ERR_R_INTERNAL_ERROR);
     *al = SSL_AD_INTERNAL_ERROR;
     return 0;
-#endif
 }
 
-static int tls_construct_cke_ecdhe(SSL *s, unsigned char **p, int *len, int *al)
+static int tls_construct_cke_ecdhe(SSL *s, WPACKET *pkt, int *al)
 {
 #ifndef OPENSSL_NO_EC
     unsigned char *encodedPoint = NULL;
-    int encoded_pt_len = 0;
+    size_t encoded_pt_len = 0;
     EVP_PKEY *ckey = NULL, *skey = NULL;
+    int ret = 0;
 
     skey = s->s3->peer_tmp;
-    if ((skey == NULL) || EVP_PKEY_get0_EC_KEY(skey) == NULL) {
+    if (skey == NULL) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_INTERNAL_ERROR);
         return 0;
     }
 
-    ckey = ssl_generate_pkey(skey, NID_undef);
+    ckey = ssl_generate_pkey(skey);
+    if (ckey == NULL) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
 
-    if (ssl_derive(s, ckey, skey) == 0) {
+    if (ssl_derive(s, ckey, skey, 0) == 0) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_EVP_LIB);
         goto err;
     }
 
     /* Generate encoding of client key */
-    encoded_pt_len = EC_KEY_key2buf(EVP_PKEY_get0_EC_KEY(ckey),
-                                    POINT_CONVERSION_UNCOMPRESSED,
-                                    &encodedPoint, NULL);
+    encoded_pt_len = EVP_PKEY_get1_tls_encodedpoint(ckey, &encodedPoint);
 
     if (encoded_pt_len == 0) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_EC_LIB);
         goto err;
     }
 
-    EVP_PKEY_free(ckey);
-    ckey = NULL;
-
-    *len = encoded_pt_len;
-
-    /* length of encoded point */
-    **p = *len;
-    *p += 1;
-    /* copy the point */
-    memcpy(*p, encodedPoint, *len);
-    /* increment len to account for length field */
-    *len += 1;
-
-    OPENSSL_free(encodedPoint);
+    if (!WPACKET_sub_memcpy_u8(pkt, encodedPoint, encoded_pt_len)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
 
-    return 1;
+    ret = 1;
  err:
+    OPENSSL_free(encodedPoint);
     EVP_PKEY_free(ckey);
-    return 0;
+    return ret;
 #else
     SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_INTERNAL_ERROR);
     *al = SSL_AD_INTERNAL_ERROR;
@@ -2272,7 +2719,7 @@ static int tls_construct_cke_ecdhe(SSL *s, unsigned char **p, int *len, int *al)
 #endif
 }
 
-static int tls_construct_cke_gost(SSL *s, unsigned char **p, int *len, int *al)
+static int tls_construct_cke_gost(SSL *s, WPACKET *pkt, int *al)
 {
 #ifndef OPENSSL_NO_GOST
     /* GOST key exchange message creation */
@@ -2318,41 +2765,30 @@ static int tls_construct_cke_gost(SSL *s, unsigned char **p, int *len, int *al)
     if (pms == NULL) {
         *al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_GOST, ERR_R_MALLOC_FAILURE);
-        return 0;
+        goto err;
     }
 
     if (EVP_PKEY_encrypt_init(pkey_ctx) <= 0
-            /* Generate session key */
-            || RAND_bytes(pms, pmslen) <= 0) {
+        /* Generate session key
+         * TODO(size_t): Convert this function
+         */
+        || RAND_bytes(pms, (int)pmslen) <= 0) {
         *al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_GOST, ERR_R_INTERNAL_ERROR);
         goto err;
     };
-    /*
-     * If we have client certificate, use its secret as peer key
-     */
-    if (s->s3->tmp.cert_req && s->cert->key->privatekey) {
-        if (EVP_PKEY_derive_set_peer
-            (pkey_ctx, s->cert->key->privatekey) <= 0) {
-            /*
-             * If there was an error - just ignore it. Ephemeral key
-             * * would be used
-             */
-            ERR_clear_error();
-        }
-    }
     /*
      * Compute shared IV and store it in algorithm-specific context
      * data
      */
     ukm_hash = EVP_MD_CTX_new();
     if (ukm_hash == NULL
-            || EVP_DigestInit(ukm_hash, EVP_get_digestbynid(dgst_nid)) <= 0
-            || EVP_DigestUpdate(ukm_hash, s->s3->client_random,
-                                SSL3_RANDOM_SIZE) <= 0
-            || EVP_DigestUpdate(ukm_hash, s->s3->server_random,
-                                SSL3_RANDOM_SIZE) <= 0
-            || EVP_DigestFinal_ex(ukm_hash, shared_ukm, &md_len) <= 0) {
+        || EVP_DigestInit(ukm_hash, EVP_get_digestbynid(dgst_nid)) <= 0
+        || EVP_DigestUpdate(ukm_hash, s->s3->client_random,
+                            SSL3_RANDOM_SIZE) <= 0
+        || EVP_DigestUpdate(ukm_hash, s->s3->server_random,
+                            SSL3_RANDOM_SIZE) <= 0
+        || EVP_DigestFinal_ex(ukm_hash, shared_ukm, &md_len) <= 0) {
         *al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_GOST, ERR_R_INTERNAL_ERROR);
         goto err;
@@ -2369,28 +2805,21 @@ static int tls_construct_cke_gost(SSL *s, unsigned char **p, int *len, int *al)
     /*
      * Encapsulate it into sequence
      */
-    *((*p)++) = V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED;
     msglen = 255;
     if (EVP_PKEY_encrypt(pkey_ctx, tmp, &msglen, pms, pmslen) <= 0) {
         *al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_GOST, SSL_R_LIBRARY_BUG);
         goto err;
     }
-    if (msglen >= 0x80) {
-        *((*p)++) = 0x81;
-        *((*p)++) = msglen & 0xff;
-        *len = msglen + 3;
-    } else {
-        *((*p)++) = msglen & 0xff;
-        *len = msglen + 2;
-    }
-    memcpy(*p, tmp, msglen);
-    /* Check if pubkey from client certificate was used */
-    if (EVP_PKEY_CTX_ctrl(pkey_ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 2,
-                          NULL) > 0) {
-        /* Set flag "skip certificate verify" */
-        s->s3->flags |= TLS1_FLAGS_SKIP_CERT_VERIFY;
+
+    if (!WPACKET_put_bytes_u8(pkt, V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)
+            || (msglen >= 0x80 && !WPACKET_put_bytes_u8(pkt, 0x81))
+            || !WPACKET_sub_memcpy_u8(pkt, tmp, msglen)) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_CONSTRUCT_CKE_GOST, ERR_R_INTERNAL_ERROR);
+        goto err;
     }
+
     EVP_PKEY_CTX_free(pkey_ctx);
     s->s3->tmp.pms = pms;
     s->s3->tmp.pmslen = pmslen;
@@ -2408,19 +2837,19 @@ static int tls_construct_cke_gost(SSL *s, unsigned char **p, int *len, int *al)
 #endif
 }
 
-static int tls_construct_cke_srp(SSL *s, unsigned char **p, int *len, int *al)
+static int tls_construct_cke_srp(SSL *s, WPACKET *pkt, int *al)
 {
-#ifndef OPENSSL_NO_SRT
-    if (s->srp_ctx.A != NULL) {
-        /* send off the data */
-        *len = BN_num_bytes(s->srp_ctx.A);
-        s2n(*len, *p);
-        BN_bn2bin(s->srp_ctx.A, *p);
-        *len += 2;
-    } else {
+#ifndef OPENSSL_NO_SRP
+    unsigned char *abytes = NULL;
+
+    if (s->srp_ctx.A == NULL
+            || !WPACKET_sub_allocate_bytes_u16(pkt, BN_num_bytes(s->srp_ctx.A),
+                                               &abytes)) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_SRP, ERR_R_INTERNAL_ERROR);
         return 0;
     }
+    BN_bn2bin(s->srp_ctx.A, abytes);
+
     OPENSSL_free(s->session->srp_username);
     s->session->srp_username = OPENSSL_strdup(s->srp_ctx.login);
     if (s->session->srp_username == NULL) {
@@ -2436,48 +2865,33 @@ static int tls_construct_cke_srp(SSL *s, unsigned char **p, int *len, int *al)
 #endif
 }
 
-int tls_construct_client_key_exchange(SSL *s)
+int tls_construct_client_key_exchange(SSL *s, WPACKET *pkt)
 {
-    unsigned char *p;
-    int len;
-    size_t pskhdrlen = 0;
     unsigned long alg_k;
     int al = -1;
 
     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 
-    p = ssl_handshake_start(s);
-
     if ((alg_k & SSL_PSK)
-            && !tls_construct_cke_psk_preamble(s, &p, &pskhdrlen, &al))
+        && !tls_construct_cke_psk_preamble(s, pkt, &al))
         goto err;
 
-    if (alg_k & SSL_kPSK) {
-        len = 0;
-    } else if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {
-        if (!tls_construct_cke_rsa(s, &p, &len, &al))
+    if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {
+        if (!tls_construct_cke_rsa(s, pkt, &al))
             goto err;
     } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
-        if (!tls_construct_cke_dhe(s, &p, &len, &al))
+        if (!tls_construct_cke_dhe(s, pkt, &al))
             goto err;
     } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
-        if (!tls_construct_cke_ecdhe(s, &p, &len, &al))
+        if (!tls_construct_cke_ecdhe(s, pkt, &al))
             goto err;
     } else if (alg_k & SSL_kGOST) {
-        if (!tls_construct_cke_gost(s, &p, &len, &al))
+        if (!tls_construct_cke_gost(s, pkt, &al))
             goto err;
     } else if (alg_k & SSL_kSRP) {
-        if (!tls_construct_cke_srp(s, &p, &len, &al))
+        if (!tls_construct_cke_srp(s, pkt, &al))
             goto err;
-    } else {
-        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
-        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
-        goto err;
-    }
-
-    len += pskhdrlen;
-
-    if (!ssl_set_handshake_header(s, SSL3_MT_CLIENT_KEY_EXCHANGE, len)) {
+    } else if (!(alg_k & SSL_kPSK)) {
         ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
         SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
         goto err;
@@ -2493,7 +2907,6 @@ int tls_construct_client_key_exchange(SSL *s)
     OPENSSL_clear_free(s->s3->tmp.psk, s->s3->tmp.psklen);
     s->s3->tmp.psk = NULL;
 #endif
-    ossl_statem_set_error(s);
     return 0;
 }
 
@@ -2546,8 +2959,8 @@ int tls_client_key_exchange_post_work(SSL *s)
                sizeof(DTLS1_SCTP_AUTH_LABEL));
 
         if (SSL_export_keying_material(s, sctpauthkey,
-                                   sizeof(sctpauthkey), labelbuffer,
-                                   sizeof(labelbuffer), NULL, 0, 0) <= 0)
+                                       sizeof(sctpauthkey), labelbuffer,
+                                       sizeof(labelbuffer), NULL, 0, 0) <= 0)
             goto err;
 
         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
@@ -2562,79 +2975,6 @@ int tls_client_key_exchange_post_work(SSL *s)
     return 0;
 }
 
-int tls_construct_client_verify(SSL *s)
-{
-    unsigned char *p;
-    EVP_PKEY *pkey;
-    const EVP_MD *md = s->s3->tmp.md[s->cert->key - s->cert->pkeys];
-    EVP_MD_CTX *mctx;
-    unsigned u = 0;
-    unsigned long n = 0;
-    long hdatalen = 0;
-    void *hdata;
-
-    mctx = EVP_MD_CTX_new();
-    if (mctx == NULL) {
-        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_VERIFY, ERR_R_MALLOC_FAILURE);
-        goto err;
-    }
-
-    p = ssl_handshake_start(s);
-    pkey = s->cert->key->privatekey;
-
-    hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
-    if (hdatalen <= 0) {
-        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_VERIFY, ERR_R_INTERNAL_ERROR);
-        goto err;
-    }
-    if (SSL_USE_SIGALGS(s)) {
-        if (!tls12_get_sigandhash(p, pkey, md)) {
-            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_VERIFY, ERR_R_INTERNAL_ERROR);
-            goto err;
-        }
-        p += 2;
-        n = 2;
-    }
-#ifdef SSL_DEBUG
-    fprintf(stderr, "Using client alg %s\n", EVP_MD_name(md));
-#endif
-    if (!EVP_SignInit_ex(mctx, md, NULL)
-        || !EVP_SignUpdate(mctx, hdata, hdatalen)
-        || (s->version == SSL3_VERSION
-            && !EVP_MD_CTX_ctrl(mctx, EVP_CTRL_SSL3_MASTER_SECRET,
-                                s->session->master_key_length,
-                                s->session->master_key))
-        || !EVP_SignFinal(mctx, p + 2, &u, pkey)) {
-        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_VERIFY, ERR_R_EVP_LIB);
-        goto err;
-    }
-#ifndef OPENSSL_NO_GOST
-    {
-        int pktype = EVP_PKEY_id(pkey);
-        if (pktype == NID_id_GostR3410_2001
-            || pktype == NID_id_GostR3410_2012_256
-            || pktype == NID_id_GostR3410_2012_512)
-            BUF_reverse(p + 2, NULL, u);
-    }
-#endif
-
-    s2n(u, p);
-    n += u + 2;
-    /* Digest cached records and discard handshake buffer */
-    if (!ssl3_digest_cached_records(s, 0))
-        goto err;
-    if (!ssl_set_handshake_header(s, SSL3_MT_CERTIFICATE_VERIFY, n)) {
-        SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_VERIFY, ERR_R_INTERNAL_ERROR);
-        goto err;
-    }
-
-    EVP_MD_CTX_free(mctx);
-    return 1;
- err:
-    EVP_MD_CTX_free(mctx);
-    return 0;
-}
-
 /*
  * Check a certificate can be used for client authentication. Currently check
  * cert exists, if we have a suitable digest for TLS 1.2 if static DH client
@@ -2732,14 +3072,21 @@ WORK_STATE tls_prepare_client_certificate(SSL *s, WORK_STATE wst)
     return WORK_ERROR;
 }
 
-int tls_construct_client_certificate(SSL *s)
+int tls_construct_client_certificate(SSL *s, WPACKET *pkt)
 {
-    if (!ssl3_output_cert_chain(s,
-                                (s->s3->tmp.cert_req ==
-                                 2) ? NULL : s->cert->key)) {
+    int al = SSL_AD_INTERNAL_ERROR;
+
+    /*
+     * TODO(TLS1.3): For now we must put an empty context. Needs to be filled in
+     * later
+     */
+    if ((SSL_IS_TLS13(s) && !WPACKET_put_bytes_u8(pkt, 0))
+            || !ssl3_output_cert_chain(s, pkt,
+                               (s->s3->tmp.cert_req == 2) ? NULL
+                                                          : s->cert->key,
+                                &al)) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
-        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
-        ossl_statem_set_error(s);
+        ssl3_send_alert(s, SSL3_AL_FATAL, al);
         return 0;
     }
 
@@ -2822,27 +3169,81 @@ int ssl3_check_cert_and_algorithm(SSL *s)
 }
 
 #ifndef OPENSSL_NO_NEXTPROTONEG
-int tls_construct_next_proto(SSL *s)
+int tls_construct_next_proto(SSL *s, WPACKET *pkt)
 {
-    unsigned int len, padding_len;
-    unsigned char *d;
+    size_t len, padding_len;
+    unsigned char *padding = NULL;
 
-    len = s->next_proto_negotiated_len;
+    len = s->ext.npn_len;
     padding_len = 32 - ((len + 2) % 32);
-    d = (unsigned char *)s->init_buf->data;
-    d[4] = len;
-    memcpy(d + 5, s->next_proto_negotiated, len);
-    d[5 + len] = padding_len;
-    memset(d + 6 + len, 0, padding_len);
-    *(d++) = SSL3_MT_NEXT_PROTO;
-    l2n3(2 + len + padding_len, d);
-    s->init_num = 4 + 2 + len + padding_len;
-    s->init_off = 0;
+
+    if (!WPACKET_sub_memcpy_u8(pkt, s->ext.npn, len)
+            || !WPACKET_sub_allocate_bytes_u8(pkt, padding_len, &padding)) {
+        SSLerr(SSL_F_TLS_CONSTRUCT_NEXT_PROTO, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    memset(padding, 0, padding_len);
 
     return 1;
+ err:
+    ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+    return 0;
 }
 #endif
 
+MSG_PROCESS_RETURN tls_process_hello_req(SSL *s, PACKET *pkt)
+{
+    if (PACKET_remaining(pkt) > 0) {
+        /* should contain no data */
+        SSLerr(SSL_F_TLS_PROCESS_HELLO_REQ, SSL_R_LENGTH_MISMATCH);
+        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
+        ossl_statem_set_error(s);
+        return MSG_PROCESS_ERROR;
+    }
+
+    /*
+     * This is a historical discrepancy maintained for compatibility
+     * reasons. If a TLS client receives a HelloRequest it will attempt
+     * an abbreviated handshake. However if a DTLS client receives a
+     * HelloRequest it will do a full handshake.
+     */
+    if (SSL_IS_DTLS(s))
+        SSL_renegotiate(s);
+    else
+        SSL_renegotiate_abbreviated(s);
+
+    return MSG_PROCESS_FINISHED_READING;
+}
+
+static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt)
+{
+    int al = SSL_AD_INTERNAL_ERROR;
+    PACKET extensions;
+    RAW_EXTENSION *rawexts = NULL;
+
+    if (!PACKET_as_length_prefixed_2(pkt, &extensions)) {
+        al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_ENCRYPTED_EXTENSIONS, SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    if (!tls_collect_extensions(s, &extensions, EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
+                                &rawexts, &al)
+            || !tls_parse_all_extensions(s, EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
+                                         rawexts, NULL, 0, &al))
+        goto err;
+
+    OPENSSL_free(rawexts);
+    return MSG_PROCESS_CONTINUE_READING;
+
+ err:
+    ssl3_send_alert(s, SSL3_AL_FATAL, al);
+    ossl_statem_set_error(s);
+    OPENSSL_free(rawexts);
+    return MSG_PROCESS_ERROR;
+}
+
 int ssl_do_client_cert_cb(SSL *s, X509 **px509, EVP_PKEY **ppkey)
 {
     int i = 0;
@@ -2860,48 +3261,79 @@ int ssl_do_client_cert_cb(SSL *s, X509 **px509, EVP_PKEY **ppkey)
     return i;
 }
 
-int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
-                             unsigned char *p)
+int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, WPACKET *pkt)
 {
-    int i, j = 0;
-    const SSL_CIPHER *c;
-    unsigned char *q;
+    int i;
+    size_t totlen = 0, len, maxlen;
     int empty_reneg_info_scsv = !s->renegotiate;
     /* Set disabled masks for this session */
     ssl_set_client_disabled(s);
 
     if (sk == NULL)
         return (0);
-    q = p;
 
-    for (i = 0; i < sk_SSL_CIPHER_num(sk); i++) {
+#ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
+# if OPENSSL_MAX_TLS1_2_CIPHER_LENGTH < 6
+#  error Max cipher length too short
+# endif
+    /*
+     * Some servers hang if client hello > 256 bytes as hack workaround
+     * chop number of supported ciphers to keep it well below this if we
+     * use TLS v1.2
+     */
+    if (TLS1_get_version(s) >= TLS1_2_VERSION)
+        maxlen = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
+    else
+#endif
+        /* Maximum length that can be stored in 2 bytes. Length must be even */
+        maxlen = 0xfffe;
+
+    if (empty_reneg_info_scsv)
+        maxlen -= 2;
+    if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV)
+        maxlen -= 2;
+
+    for (i = 0; i < sk_SSL_CIPHER_num(sk) && totlen < maxlen; i++) {
+        const SSL_CIPHER *c;
+
         c = sk_SSL_CIPHER_value(sk, i);
         /* Skip disabled ciphers */
         if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED))
             continue;
-        j = s->method->put_cipher_by_char(c, p);
-        p += j;
+
+        if (!s->method->put_cipher_by_char(c, pkt, &len)) {
+            SSLerr(SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
+            return 0;
+        }
+
+        totlen += len;
     }
-    /*
-     * If p == q, no ciphers; caller indicates an error. Otherwise, add
-     * applicable SCSVs.
-     */
-    if (p != q) {
+
+    if (totlen == 0) {
+        SSLerr(SSL_F_SSL_CIPHER_LIST_TO_BYTES, SSL_R_NO_CIPHERS_AVAILABLE);
+        return 0;
+    }
+
+    if (totlen != 0) {
         if (empty_reneg_info_scsv) {
             static SSL_CIPHER scsv = {
                 0, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
             };
-            j = s->method->put_cipher_by_char(&scsv, p);
-            p += j;
+            if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
+                SSLerr(SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
+                return 0;
+            }
         }
         if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV) {
             static SSL_CIPHER scsv = {
                 0, NULL, SSL3_CK_FALLBACK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
             };
-            j = s->method->put_cipher_by_char(&scsv, p);
-            p += j;
+            if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
+                SSLerr(SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
+                return 0;
+            }
         }
     }
 
-    return (p - q);
+    return 1;
 }