zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/lib/libssl/openssl-1.1.1o/ssl/statem/statem_clnt.c b/ap/lib/libssl/openssl-1.1.1o/ssl/statem/statem_clnt.c
new file mode 100644
index 0000000..d19c44e
--- /dev/null
+++ b/ap/lib/libssl/openssl-1.1.1o/ssl/statem/statem_clnt.c
@@ -0,0 +1,3855 @@
+/*
+ * Copyright 1995-2022 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
+ * Copyright 2005 Nokia. All rights reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <stdio.h>
+#include <time.h>
+#include <assert.h>
+#include "../ssl_local.h"
+#include "statem_local.h"
+#include <openssl/buffer.h>
+#include <openssl/rand.h>
+#include <openssl/objects.h>
+#include <openssl/evp.h>
+#include <openssl/md5.h>
+#include <openssl/dh.h>
+#include <openssl/bn.h>
+#include <openssl/engine.h>
+#include <internal/cryptlib.h>
+
+static MSG_PROCESS_RETURN tls_process_as_hello_retry_request(SSL *s, PACKET *pkt);
+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 ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
+                                    WPACKET *pkt);
+
+/*
+ * Is a CertificateRequest message allowed at the moment or not?
+ *
+ *  Return values are:
+ *  1: Yes
+ *  0: No
+ */
+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)))
+        return 0;
+
+    return 1;
+}
+
+/*
+ * Should we expect the ServerKeyExchange message or not?
+ *
+ *  Return values are:
+ *  1: Yes
+ *  0: No
+ */
+static int key_exchange_expected(SSL *s)
+{
+    long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
+
+    /*
+     * Can't skip server key exchange if this is an ephemeral
+     * ciphersuite or for SRP
+     */
+    if (alg_k & (SSL_kDHE | SSL_kECDHE | SSL_kDHEPSK | SSL_kECDHEPSK
+                 | SSL_kSRP)) {
+        return 1;
+    }
+
+    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;
+
+    /*
+     * 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_CW_CLNT_HELLO:
+        /*
+         * This must a ClientHello following a HelloRetryRequest, so the only
+         * thing we can get now is a ServerHello.
+         */
+        if (mt == SSL3_MT_SERVER_HELLO) {
+            st->hand_state = TLS_ST_CR_SRVR_HELLO;
+            return 1;
+        }
+        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;
+        }
+        if (mt == SSL3_MT_KEY_UPDATE) {
+            st->hand_state = TLS_ST_CR_KEY_UPDATE;
+            return 1;
+        }
+        if (mt == SSL3_MT_CERTIFICATE_REQUEST) {
+#if DTLS_MAX_VERSION != DTLS1_2_VERSION
+# error TODO(DTLS1.3): Restore digest for PHA before adding message.
+#endif
+            if (!SSL_IS_DTLS(s) && s->post_handshake_auth == SSL_PHA_EXT_SENT) {
+                s->post_handshake_auth = SSL_PHA_REQUESTED;
+                /*
+                 * In TLS, this is called before the message is added to the
+                 * digest. In DTLS, this is expected to be called after adding
+                 * to the digest. Either move the digest restore, or add the
+                 * message here after the swap, or do it after the clientFinished?
+                 */
+                if (!tls13_restore_handshake_digest_for_pha(s)) {
+                    /* SSLfatal() already called */
+                    return 0;
+                }
+                st->hand_state = TLS_ST_CR_CERT_REQ;
+                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 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;
+
+    /*
+     * Note that after writing the first 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;
+            return 1;
+        }
+
+        if (SSL_IS_DTLS(s)) {
+            if (mt == DTLS1_MT_HELLO_VERIFY_REQUEST) {
+                st->hand_state = DTLS_ST_CR_HELLO_VERIFY_REQUEST;
+                return 1;
+            }
+        }
+        break;
+
+    case TLS_ST_EARLY_DATA:
+        /*
+         * We've not actually selected TLSv1.3 yet, but we have sent early
+         * data. The only thing allowed now is a ServerHello or a
+         * HelloRetryRequest.
+         */
+        if (mt == SSL3_MT_SERVER_HELLO) {
+            st->hand_state = TLS_ST_CR_SRVR_HELLO;
+            return 1;
+        }
+        break;
+
+    case TLS_ST_CR_SRVR_HELLO:
+        if (s->hit) {
+            if (s->ext.ticket_expected) {
+                if (mt == SSL3_MT_NEWSESSION_TICKET) {
+                    st->hand_state = TLS_ST_CR_SESSION_TICKET;
+                    return 1;
+                }
+            } else if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+                st->hand_state = TLS_ST_CR_CHANGE;
+                return 1;
+            }
+        } else {
+            if (SSL_IS_DTLS(s) && mt == DTLS1_MT_HELLO_VERIFY_REQUEST) {
+                st->hand_state = DTLS_ST_CR_HELLO_VERIFY_REQUEST;
+                return 1;
+            } else if (s->version >= TLS1_VERSION
+                       && 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
+                 * the next server message after the ServerHello to determine if
+                 * the server is resuming.
+                 */
+                s->hit = 1;
+                st->hand_state = TLS_ST_CR_CHANGE;
+                return 1;
+            } else if (!(s->s3->tmp.new_cipher->algorithm_auth
+                         & (SSL_aNULL | SSL_aSRP | SSL_aPSK))) {
+                if (mt == SSL3_MT_CERTIFICATE) {
+                    st->hand_state = TLS_ST_CR_CERT;
+                    return 1;
+                }
+            } else {
+                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 (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;
+                } else if (mt == SSL3_MT_SERVER_DONE) {
+                    st->hand_state = TLS_ST_CR_SRVR_DONE;
+                    return 1;
+                }
+            }
+        }
+        break;
+
+    case TLS_ST_CR_CERT:
+        /*
+         * The CertificateStatus message is optional even if
+         * |ext.status_expected| is set
+         */
+        if (s->ext.status_expected && mt == SSL3_MT_CERTIFICATE_STATUS) {
+            st->hand_state = TLS_ST_CR_CERT_STATUS;
+            return 1;
+        }
+        /* Fall through */
+
+    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 (mt == SSL3_MT_SERVER_KEY_EXCHANGE) {
+                st->hand_state = TLS_ST_CR_KEY_EXCH;
+                return 1;
+            }
+            goto err;
+        }
+        /* Fall through */
+
+    case TLS_ST_CR_KEY_EXCH:
+        if (mt == SSL3_MT_CERTIFICATE_REQUEST) {
+            if (cert_req_allowed(s)) {
+                st->hand_state = TLS_ST_CR_CERT_REQ;
+                return 1;
+            }
+            goto err;
+        }
+        /* Fall through */
+
+    case TLS_ST_CR_CERT_REQ:
+        if (mt == SSL3_MT_SERVER_DONE) {
+            st->hand_state = TLS_ST_CR_SRVR_DONE;
+            return 1;
+        }
+        break;
+
+    case TLS_ST_CW_FINISHED:
+        if (s->ext.ticket_expected) {
+            if (mt == SSL3_MT_NEWSESSION_TICKET) {
+                st->hand_state = TLS_ST_CR_SESSION_TICKET;
+                return 1;
+            }
+        } else if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+            st->hand_state = TLS_ST_CR_CHANGE;
+            return 1;
+        }
+        break;
+
+    case TLS_ST_CR_SESSION_TICKET:
+        if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+            st->hand_state = TLS_ST_CR_CHANGE;
+            return 1;
+        }
+        break;
+
+    case TLS_ST_CR_CHANGE:
+        if (mt == SSL3_MT_FINISHED) {
+            st->hand_state = TLS_ST_CR_FINISHED;
+            return 1;
+        }
+        break;
+
+    case TLS_ST_OK:
+        if (mt == SSL3_MT_HELLO_REQUEST) {
+            st->hand_state = TLS_ST_CR_HELLO_REQ;
+            return 1;
+        }
+        break;
+    }
+
+ err:
+    /* No valid transition found */
+    if (SSL_IS_DTLS(s) && mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+        BIO *rbio;
+
+        /*
+         * CCS messages don't have a message sequence number so this is probably
+         * because of an out-of-order CCS. We'll just drop it.
+         */
+        s->init_num = 0;
+        s->rwstate = SSL_READING;
+        rbio = SSL_get_rbio(s);
+        BIO_clear_retry_flags(rbio);
+        BIO_set_retry_read(rbio);
+        return 0;
+    }
+    SSLfatal(s, SSL3_AD_UNEXPECTED_MESSAGE,
+             SSL_F_OSSL_STATEM_CLIENT_READ_TRANSITION,
+             SSL_R_UNEXPECTED_MESSAGE);
+    return 0;
+}
+
+/*
+ * 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;
+
+    /*
+     * Note: There are no cases for TLS_ST_BEFORE 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 */
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_OSSL_STATEM_CLIENT13_WRITE_TRANSITION,
+                 ERR_R_INTERNAL_ERROR);
+        return WRITE_TRAN_ERROR;
+
+    case TLS_ST_CR_CERT_REQ:
+        if (s->post_handshake_auth == SSL_PHA_REQUESTED) {
+            st->hand_state = TLS_ST_CW_CERT;
+            return WRITE_TRAN_CONTINUE;
+        }
+        /*
+         * We should only get here if we received a CertificateRequest after
+         * we already sent close_notify
+         */
+        if (!ossl_assert((s->shutdown & SSL_SENT_SHUTDOWN) != 0)) {
+            /* Shouldn't happen - same as default case */
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_OSSL_STATEM_CLIENT13_WRITE_TRANSITION,
+                     ERR_R_INTERNAL_ERROR);
+            return WRITE_TRAN_ERROR;
+        }
+        st->hand_state = TLS_ST_OK;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CR_FINISHED:
+        if (s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY
+                || s->early_data_state == SSL_EARLY_DATA_FINISHED_WRITING)
+            st->hand_state = TLS_ST_PENDING_EARLY_DATA_END;
+        else if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0
+                 && s->hello_retry_request == SSL_HRR_NONE)
+            st->hand_state = TLS_ST_CW_CHANGE;
+        else
+            st->hand_state = (s->s3->tmp.cert_req != 0) ? TLS_ST_CW_CERT
+                                                        : TLS_ST_CW_FINISHED;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_PENDING_EARLY_DATA_END:
+        if (s->ext.early_data == SSL_EARLY_DATA_ACCEPTED) {
+            st->hand_state = TLS_ST_CW_END_OF_EARLY_DATA;
+            return WRITE_TRAN_CONTINUE;
+        }
+        /* Fall through */
+
+    case TLS_ST_CW_END_OF_EARLY_DATA:
+    case TLS_ST_CW_CHANGE:
+        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_KEY_UPDATE:
+    case TLS_ST_CW_KEY_UPDATE:
+    case TLS_ST_CR_SESSION_TICKET:
+    case TLS_ST_CW_FINISHED:
+        st->hand_state = TLS_ST_OK;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_OK:
+        if (s->key_update != SSL_KEY_UPDATE_NONE) {
+            st->hand_state = TLS_ST_CW_KEY_UPDATE;
+            return WRITE_TRAN_CONTINUE;
+        }
+
+        /* Try to read from the server instead */
+        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;
+
+    /*
+     * 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 */
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_OSSL_STATEM_CLIENT_WRITE_TRANSITION,
+                 ERR_R_INTERNAL_ERROR);
+        return WRITE_TRAN_ERROR;
+
+    case TLS_ST_OK:
+        if (!s->renegotiate) {
+            /*
+             * 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 thru */
+    case TLS_ST_BEFORE:
+        st->hand_state = TLS_ST_CW_CLNT_HELLO;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CW_CLNT_HELLO:
+        if (s->early_data_state == SSL_EARLY_DATA_CONNECTING) {
+            /*
+             * We are assuming this is a TLSv1.3 connection, although we haven't
+             * actually selected a version yet.
+             */
+            if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0)
+                st->hand_state = TLS_ST_CW_CHANGE;
+            else
+                st->hand_state = TLS_ST_EARLY_DATA;
+            return WRITE_TRAN_CONTINUE;
+        }
+        /*
+         * 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_HELLO:
+        /*
+         * We only get here in TLSv1.3. We just received an HRR, so issue a
+         * CCS unless middlebox compat mode is off, or we already issued one
+         * because we did early data.
+         */
+        if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0
+                && s->early_data_state != SSL_EARLY_DATA_FINISHED_WRITING)
+            st->hand_state = TLS_ST_CW_CHANGE;
+        else
+            st->hand_state = TLS_ST_CW_CLNT_HELLO;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_EARLY_DATA:
+        return WRITE_TRAN_FINISHED;
+
+    case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
+        st->hand_state = TLS_ST_CW_CLNT_HELLO;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CR_SRVR_DONE:
+        if (s->s3->tmp.cert_req)
+            st->hand_state = TLS_ST_CW_CERT;
+        else
+            st->hand_state = TLS_ST_CW_KEY_EXCH;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CW_CERT:
+        st->hand_state = TLS_ST_CW_KEY_EXCH;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CW_KEY_EXCH:
+        /*
+         * For TLS, cert_req is set to 2, so a cert chain of nothing is
+         * sent, but no verify packet is sent
+         */
+        /*
+         * XXX: For now, we do not support client authentication in ECDH
+         * cipher suites with ECDH (rather than ECDSA) certificates. We
+         * need to skip the certificate verify message when client's
+         * ECDH public key is sent inside the client certificate.
+         */
+        if (s->s3->tmp.cert_req == 1) {
+            st->hand_state = TLS_ST_CW_CERT_VRFY;
+        } else {
+            st->hand_state = TLS_ST_CW_CHANGE;
+        }
+        if (s->s3->flags & TLS1_FLAGS_SKIP_CERT_VERIFY) {
+            st->hand_state = TLS_ST_CW_CHANGE;
+        }
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CW_CERT_VRFY:
+        st->hand_state = TLS_ST_CW_CHANGE;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_CW_CHANGE:
+        if (s->hello_retry_request == SSL_HRR_PENDING) {
+            st->hand_state = TLS_ST_CW_CLNT_HELLO;
+        } else if (s->early_data_state == SSL_EARLY_DATA_CONNECTING) {
+            st->hand_state = TLS_ST_EARLY_DATA;
+        } else {
+#if defined(OPENSSL_NO_NEXTPROTONEG)
+            st->hand_state = TLS_ST_CW_FINISHED;
+#else
+            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;
+
+#if !defined(OPENSSL_NO_NEXTPROTONEG)
+    case TLS_ST_CW_NEXT_PROTO:
+        st->hand_state = TLS_ST_CW_FINISHED;
+        return WRITE_TRAN_CONTINUE;
+#endif
+
+    case TLS_ST_CW_FINISHED:
+        if (s->hit) {
+            st->hand_state = TLS_ST_OK;
+            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;
+            return WRITE_TRAN_CONTINUE;
+        }
+
+    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)) {
+                /* SSLfatal() already called */
+                return WRITE_TRAN_ERROR;
+            }
+            st->hand_state = TLS_ST_CW_CLNT_HELLO;
+            return WRITE_TRAN_CONTINUE;
+        }
+        st->hand_state = TLS_ST_OK;
+        return WRITE_TRAN_CONTINUE;
+    }
+}
+
+/*
+ * Perform any pre work that needs to be done prior to sending a message from
+ * the client to the server.
+ */
+WORK_STATE ossl_statem_client_pre_work(SSL *s, WORK_STATE wst)
+{
+    OSSL_STATEM *st = &s->statem;
+
+    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)) {
+            /* every DTLS ClientHello resets Finished MAC */
+            if (!ssl3_init_finished_mac(s)) {
+                /* SSLfatal() already called */
+                return WORK_ERROR;
+            }
+        }
+        break;
+
+    case TLS_ST_CW_CHANGE:
+        if (SSL_IS_DTLS(s)) {
+            if (s->hit) {
+                /*
+                 * We're into the last flight so we don't retransmit these
+                 * messages unless we need to.
+                 */
+                st->use_timer = 0;
+            }
+#ifndef OPENSSL_NO_SCTP
+            if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
+                /* Calls SSLfatal() as required */
+                return dtls_wait_for_dry(s);
+            }
+#endif
+        }
+        break;
+
+    case TLS_ST_PENDING_EARLY_DATA_END:
+        /*
+         * If we've been called by SSL_do_handshake()/SSL_write(), or we did not
+         * attempt to write early data before calling SSL_read() then we press
+         * on with the handshake. Otherwise we pause here.
+         */
+        if (s->early_data_state == SSL_EARLY_DATA_FINISHED_WRITING
+                || s->early_data_state == SSL_EARLY_DATA_NONE)
+            return WORK_FINISHED_CONTINUE;
+        /* Fall through */
+
+    case TLS_ST_EARLY_DATA:
+        return tls_finish_handshake(s, wst, 0, 1);
+
+    case TLS_ST_OK:
+        /* Calls SSLfatal() as required */
+        return tls_finish_handshake(s, wst, 1, 1);
+    }
+
+    return WORK_FINISHED_CONTINUE;
+}
+
+/*
+ * Perform any work that needs to be done after sending a message from the
+ * client to the server.
+ */
+WORK_STATE ossl_statem_client_post_work(SSL *s, WORK_STATE wst)
+{
+    OSSL_STATEM *st = &s->statem;
+
+    s->init_num = 0;
+
+    switch (st->hand_state) {
+    default:
+        /* No post work to be done */
+        break;
+
+    case TLS_ST_CW_CLNT_HELLO:
+        if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
+                && s->max_early_data > 0) {
+            /*
+             * We haven't selected TLSv1.3 yet so we don't call the change
+             * cipher state function associated with the SSL_METHOD. Instead
+             * we call tls13_change_cipher_state() directly.
+             */
+            if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) == 0) {
+                if (!tls13_change_cipher_state(s,
+                            SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
+                    /* SSLfatal() already called */
+                    return WORK_ERROR;
+                }
+            }
+            /* else we're in compat mode so we delay flushing until after CCS */
+        } else if (!statem_flush(s)) {
+            return WORK_MORE_A;
+        }
+
+        if (SSL_IS_DTLS(s)) {
+            /* Treat the next message as the first packet */
+            s->first_packet = 1;
+        }
+        break;
+
+    case TLS_ST_CW_END_OF_EARLY_DATA:
+        /*
+         * We set the enc_write_ctx back to NULL because we may end up writing
+         * in cleartext again if we get a HelloRetryRequest from the server.
+         */
+        EVP_CIPHER_CTX_free(s->enc_write_ctx);
+        s->enc_write_ctx = NULL;
+        break;
+
+    case TLS_ST_CW_KEY_EXCH:
+        if (tls_client_key_exchange_post_work(s) == 0) {
+            /* SSLfatal() already called */
+            return WORK_ERROR;
+        }
+        break;
+
+    case TLS_ST_CW_CHANGE:
+        if (SSL_IS_TLS13(s) || s->hello_retry_request == SSL_HRR_PENDING)
+            break;
+        if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
+                    && s->max_early_data > 0) {
+            /*
+             * We haven't selected TLSv1.3 yet so we don't call the change
+             * cipher state function associated with the SSL_METHOD. Instead
+             * we call tls13_change_cipher_state() directly.
+             */
+            if (!tls13_change_cipher_state(s,
+                        SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_CLIENT_WRITE))
+                return WORK_ERROR;
+            break;
+        }
+        s->session->cipher = s->s3->tmp.new_cipher;
+#ifdef OPENSSL_NO_COMP
+        s->session->compress_meth = 0;
+#else
+        if (s->s3->tmp.new_compression == NULL)
+            s->session->compress_meth = 0;
+        else
+            s->session->compress_meth = s->s3->tmp.new_compression->id;
+#endif
+        if (!s->method->ssl3_enc->setup_key_block(s)) {
+            /* SSLfatal() already called */
+            return WORK_ERROR;
+        }
+
+        if (!s->method->ssl3_enc->change_cipher_state(s,
+                                          SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
+            /* SSLfatal() already called */
+            return WORK_ERROR;
+        }
+
+        if (SSL_IS_DTLS(s)) {
+#ifndef OPENSSL_NO_SCTP
+            if (s->hit) {
+                /*
+                 * Change to new shared key of SCTP-Auth, will be ignored if
+                 * no SCTP used.
+                 */
+                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
+                         0, NULL);
+            }
+#endif
+
+            dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
+        }
+        break;
+
+    case TLS_ST_CW_FINISHED:
+#ifndef OPENSSL_NO_SCTP
+        if (wst == WORK_MORE_A && SSL_IS_DTLS(s) && s->hit == 0) {
+            /*
+             * Change to new shared key of SCTP-Auth, will be ignored if
+             * no SCTP used.
+             */
+            BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
+                     0, NULL);
+        }
+#endif
+        if (statem_flush(s) != 1)
+            return WORK_MORE_B;
+
+        if (SSL_IS_TLS13(s)) {
+            if (!tls13_save_handshake_digest_for_pha(s)) {
+                /* SSLfatal() already called */
+                return WORK_ERROR;
+            }
+            if (s->post_handshake_auth != SSL_PHA_REQUESTED) {
+                if (!s->method->ssl3_enc->change_cipher_state(s,
+                        SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
+                    /* SSLfatal() already called */
+                    return WORK_ERROR;
+                }
+            }
+        }
+        break;
+
+    case TLS_ST_CW_KEY_UPDATE:
+        if (statem_flush(s) != 1)
+            return WORK_MORE_A;
+        if (!tls13_update_key(s, 1)) {
+            /* SSLfatal() already called */
+            return WORK_ERROR;
+        }
+        break;
+    }
+
+    return WORK_FINISHED_CONTINUE;
+}
+
+/*
+ * 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, WPACKET *pkt,
+                                         confunc_f *confunc, int *mt)
+{
+    OSSL_STATEM *st = &s->statem;
+
+    switch (st->hand_state) {
+    default:
+        /* Shouldn't happen */
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_OSSL_STATEM_CLIENT_CONSTRUCT_MESSAGE,
+                 SSL_R_BAD_HANDSHAKE_STATE);
+        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:
+        *confunc = tls_construct_client_hello;
+        *mt = SSL3_MT_CLIENT_HELLO;
+        break;
+
+    case TLS_ST_CW_END_OF_EARLY_DATA:
+        *confunc = tls_construct_end_of_early_data;
+        *mt = SSL3_MT_END_OF_EARLY_DATA;
+        break;
+
+    case TLS_ST_PENDING_EARLY_DATA_END:
+        *confunc = NULL;
+        *mt = SSL3_MT_DUMMY;
+        break;
+
+    case TLS_ST_CW_CERT:
+        *confunc = tls_construct_client_certificate;
+        *mt = SSL3_MT_CERTIFICATE;
+        break;
+
+    case TLS_ST_CW_KEY_EXCH:
+        *confunc = tls_construct_client_key_exchange;
+        *mt = SSL3_MT_CLIENT_KEY_EXCHANGE;
+        break;
+
+    case TLS_ST_CW_CERT_VRFY:
+        *confunc = tls_construct_cert_verify;
+        *mt = SSL3_MT_CERTIFICATE_VERIFY;
+        break;
+
+#if !defined(OPENSSL_NO_NEXTPROTONEG)
+    case TLS_ST_CW_NEXT_PROTO:
+        *confunc = tls_construct_next_proto;
+        *mt = SSL3_MT_NEXT_PROTO;
+        break;
+#endif
+    case TLS_ST_CW_FINISHED:
+        *confunc = tls_construct_finished;
+        *mt = SSL3_MT_FINISHED;
+        break;
+
+    case TLS_ST_CW_KEY_UPDATE:
+        *confunc = tls_construct_key_update;
+        *mt = SSL3_MT_KEY_UPDATE;
+        break;
+    }
+
+    return 1;
+}
+
+/*
+ * Returns the maximum allowed length for the current message that we are
+ * reading. Excludes the message header.
+ */
+size_t ossl_statem_client_max_message_size(SSL *s)
+{
+    OSSL_STATEM *st = &s->statem;
+
+    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 TLS_ST_CR_CERT:
+        return s->max_cert_list;
+
+    case TLS_ST_CR_CERT_VRFY:
+        return SSL3_RT_MAX_PLAIN_LENGTH;
+
+    case TLS_ST_CR_CERT_STATUS:
+        return SSL3_RT_MAX_PLAIN_LENGTH;
+
+    case TLS_ST_CR_KEY_EXCH:
+        return SERVER_KEY_EXCH_MAX_LENGTH;
+
+    case TLS_ST_CR_CERT_REQ:
+        /*
+         * 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_CHANGE:
+        if (s->version == DTLS1_BAD_VER)
+            return 3;
+        return CCS_MAX_LENGTH;
+
+    case TLS_ST_CR_SESSION_TICKET:
+        return (SSL_IS_TLS13(s)) ? SESSION_TICKET_MAX_LENGTH_TLS13
+                                 : SESSION_TICKET_MAX_LENGTH_TLS12;
+
+    case TLS_ST_CR_FINISHED:
+        return FINISHED_MAX_LENGTH;
+
+    case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
+        return ENCRYPTED_EXTENSIONS_MAX_LENGTH;
+
+    case TLS_ST_CR_KEY_UPDATE:
+        return KEY_UPDATE_MAX_LENGTH;
+    }
+}
+
+/*
+ * Process a message that the client has been received from the server.
+ */
+MSG_PROCESS_RETURN ossl_statem_client_process_message(SSL *s, PACKET *pkt)
+{
+    OSSL_STATEM *st = &s->statem;
+
+    switch (st->hand_state) {
+    default:
+        /* Shouldn't happen */
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_OSSL_STATEM_CLIENT_PROCESS_MESSAGE,
+                 ERR_R_INTERNAL_ERROR);
+        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 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_STATUS:
+        return tls_process_cert_status(s, pkt);
+
+    case TLS_ST_CR_KEY_EXCH:
+        return tls_process_key_exchange(s, pkt);
+
+    case TLS_ST_CR_CERT_REQ:
+        return tls_process_certificate_request(s, pkt);
+
+    case TLS_ST_CR_SRVR_DONE:
+        return tls_process_server_done(s, pkt);
+
+    case TLS_ST_CR_CHANGE:
+        return tls_process_change_cipher_spec(s, pkt);
+
+    case TLS_ST_CR_SESSION_TICKET:
+        return tls_process_new_session_ticket(s, pkt);
+
+    case TLS_ST_CR_FINISHED:
+        return tls_process_finished(s, pkt);
+
+    case TLS_ST_CR_HELLO_REQ:
+        return tls_process_hello_req(s, pkt);
+
+    case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
+        return tls_process_encrypted_extensions(s, pkt);
+
+    case TLS_ST_CR_KEY_UPDATE:
+        return tls_process_key_update(s, pkt);
+    }
+}
+
+/*
+ * Perform any further processing required following the receipt of a message
+ * from the server
+ */
+WORK_STATE ossl_statem_client_post_process_message(SSL *s, WORK_STATE wst)
+{
+    OSSL_STATEM *st = &s->statem;
+
+    switch (st->hand_state) {
+    default:
+        /* Shouldn't happen */
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_OSSL_STATEM_CLIENT_POST_PROCESS_MESSAGE,
+                 ERR_R_INTERNAL_ERROR);
+        return WORK_ERROR;
+
+    case TLS_ST_CR_CERT_VRFY:
+    case TLS_ST_CR_CERT_REQ:
+        return tls_prepare_client_certificate(s, wst);
+    }
+}
+
+int tls_construct_client_hello(SSL *s, WPACKET *pkt)
+{
+    unsigned char *p;
+    size_t sess_id_len;
+    int i, protverr;
+#ifndef OPENSSL_NO_COMP
+    SSL_COMP *comp;
+#endif
+    SSL_SESSION *sess = s->session;
+    unsigned char *session_id;
+
+    /* Work out what SSL/TLS/DTLS version to use */
+    protverr = ssl_set_client_hello_version(s);
+    if (protverr != 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                 protverr);
+        return 0;
+    }
+
+    if (sess == NULL
+            || !ssl_version_supported(s, sess->ssl_version, NULL)
+            || !SSL_SESSION_is_resumable(sess)) {
+        if (s->hello_retry_request == SSL_HRR_NONE
+                && !ssl_get_new_session(s, 0)) {
+            /* SSLfatal() already called */
+            return 0;
+        }
+    }
+    /* else use the pre-loaded session */
+
+    p = s->s3->client_random;
+
+    /*
+     * for DTLS if client_random is initialized, reuse it, we are
+     * required to use same upon reply to HelloVerify
+     */
+    if (SSL_IS_DTLS(s)) {
+        size_t idx;
+        i = 1;
+        for (idx = 0; idx < sizeof(s->s3->client_random); idx++) {
+            if (p[idx]) {
+                i = 0;
+                break;
+            }
+        }
+    } else {
+        i = (s->hello_retry_request == SSL_HRR_NONE);
+    }
+
+    if (i && ssl_fill_hello_random(s, 0, p, sizeof(s->s3->client_random),
+                                   DOWNGRADE_NONE) <= 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    /*-
+     * version indicates the negotiated version: for example from
+     * an SSLv2/v3 compatible client hello). The client_version
+     * field is the maximum version we permit and it is also
+     * used in RSA encrypted premaster secrets. Some servers can
+     * choke if we initially report a higher version then
+     * renegotiate to a lower one in the premaster secret. This
+     * didn't happen with TLS 1.0 as most servers supported it
+     * but it can with TLS 1.1 or later if the server only supports
+     * 1.0.
+     *
+     * Possible scenario with previous logic:
+     *      1. Client hello indicates TLS 1.2
+     *      2. Server hello says TLS 1.0
+     *      3. RSA encrypted premaster secret uses 1.2.
+     *      4. Handshake proceeds using TLS 1.0.
+     *      5. Server sends hello request to renegotiate.
+     *      6. Client hello indicates TLS v1.0 as we now
+     *         know that is maximum server supports.
+     *      7. Server chokes on RSA encrypted premaster secret
+     *         containing version 1.0.
+     *
+     * For interoperability it should be OK to always use the
+     * maximum version we support in client hello and then rely
+     * on the checking of version to ensure the servers isn't
+     * being inconsistent: for example initially negotiating with
+     * 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.
+     */
+    if (!WPACKET_put_bytes_u16(pkt, s->client_version)
+            || !WPACKET_memcpy(pkt, s->s3->client_random, SSL3_RANDOM_SIZE)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    /* Session ID */
+    session_id = s->session->session_id;
+    if (s->new_session || s->session->ssl_version == TLS1_3_VERSION) {
+        if (s->version == TLS1_3_VERSION
+                && (s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0) {
+            sess_id_len = sizeof(s->tmp_session_id);
+            s->tmp_session_id_len = sess_id_len;
+            session_id = s->tmp_session_id;
+            if (s->hello_retry_request == SSL_HRR_NONE
+                    && RAND_bytes(s->tmp_session_id, sess_id_len) <= 0) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                         ERR_R_INTERNAL_ERROR);
+                return 0;
+            }
+        } else {
+            sess_id_len = 0;
+        }
+    } else {
+        assert(s->session->session_id_length <= sizeof(s->session->session_id));
+        sess_id_len = s->session->session_id_length;
+        if (s->version == TLS1_3_VERSION) {
+            s->tmp_session_id_len = sess_id_len;
+            memcpy(s->tmp_session_id, s->session->session_id, sess_id_len);
+        }
+    }
+    if (!WPACKET_start_sub_packet_u8(pkt)
+            || (sess_id_len != 0 && !WPACKET_memcpy(pkt, session_id,
+                                                    sess_id_len))
+            || !WPACKET_close(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 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)
+                || !WPACKET_sub_memcpy_u8(pkt, s->d1->cookie,
+                                          s->d1->cookie_len)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                     ERR_R_INTERNAL_ERROR);
+            return 0;
+        }
+    }
+
+    /* Ciphers supported */
+    if (!WPACKET_start_sub_packet_u16(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    if (!ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), pkt)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+    if (!WPACKET_close(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    /* COMPRESSION */
+    if (!WPACKET_start_sub_packet_u8(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+#ifndef OPENSSL_NO_COMP
+    if (ssl_allow_compression(s)
+            && s->ctx->comp_methods
+            && (SSL_IS_DTLS(s) || s->s3->tmp.max_ver < TLS1_3_VERSION)) {
+        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)) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                         ERR_R_INTERNAL_ERROR);
+                return 0;
+            }
+        }
+    }
+#endif
+    /* Add the NULL method */
+    if (!WPACKET_put_bytes_u8(pkt, 0) || !WPACKET_close(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    /* TLS extensions */
+    if (!tls_construct_extensions(s, pkt, SSL_EXT_CLIENT_HELLO, NULL, 0)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    return 1;
+}
+
+MSG_PROCESS_RETURN dtls_process_hello_verify(SSL *s, PACKET *pkt)
+{
+    size_t cookie_len;
+    PACKET cookiepkt;
+
+    if (!PACKET_forward(pkt, 2)
+        || !PACKET_get_length_prefixed_1(pkt, &cookiepkt)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS_PROCESS_HELLO_VERIFY,
+                 SSL_R_LENGTH_MISMATCH);
+        return MSG_PROCESS_ERROR;
+    }
+
+    cookie_len = PACKET_remaining(&cookiepkt);
+    if (cookie_len > sizeof(s->d1->cookie)) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_DTLS_PROCESS_HELLO_VERIFY,
+                 SSL_R_LENGTH_TOO_LONG);
+        return MSG_PROCESS_ERROR;
+    }
+
+    if (!PACKET_copy_bytes(&cookiepkt, s->d1->cookie, cookie_len)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS_PROCESS_HELLO_VERIFY,
+                 SSL_R_LENGTH_MISMATCH);
+        return MSG_PROCESS_ERROR;
+    }
+    s->d1->cookie_len = cookie_len;
+
+    return MSG_PROCESS_FINISHED_READING;
+}
+
+static int set_client_ciphersuite(SSL *s, const unsigned char *cipherchars)
+{
+    STACK_OF(SSL_CIPHER) *sk;
+    const SSL_CIPHER *c;
+    int i;
+
+    c = ssl_get_cipher_by_char(s, cipherchars, 0);
+    if (c == NULL) {
+        /* unknown cipher */
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
+                 SSL_R_UNKNOWN_CIPHER_RETURNED);
+        return 0;
+    }
+    /*
+     * If it is a disabled cipher we either didn't send it in client hello,
+     * or it's not allowed for the selected protocol. So we return an error.
+     */
+    if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_CHECK, 1)) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
+                 SSL_R_WRONG_CIPHER_RETURNED);
+        return 0;
+    }
+
+    sk = ssl_get_ciphers_by_id(s);
+    i = sk_SSL_CIPHER_find(sk, c);
+    if (i < 0) {
+        /* we did not say we would use this cipher */
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
+                 SSL_R_WRONG_CIPHER_RETURNED);
+        return 0;
+    }
+
+    if (SSL_IS_TLS13(s) && s->s3->tmp.new_cipher != NULL
+            && s->s3->tmp.new_cipher->id != c->id) {
+        /* ServerHello selected a different ciphersuite to that in the HRR */
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
+                 SSL_R_WRONG_CIPHER_RETURNED);
+        return 0;
+    }
+
+    /*
+     * Depending on the session caching (internal/external), the cipher
+     * and/or cipher_id values may not be set. Make sure that cipher_id is
+     * set and use it for comparison.
+     */
+    if (s->session->cipher != NULL)
+        s->session->cipher_id = s->session->cipher->id;
+    if (s->hit && (s->session->cipher_id != c->id)) {
+        if (SSL_IS_TLS13(s)) {
+            /*
+             * In TLSv1.3 it is valid for the server to select a different
+             * ciphersuite as long as the hash is the same.
+             */
+            if (ssl_md(c->algorithm2)
+                    != ssl_md(s->session->cipher->algorithm2)) {
+                SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+                         SSL_F_SET_CLIENT_CIPHERSUITE,
+                         SSL_R_CIPHERSUITE_DIGEST_HAS_CHANGED);
+                return 0;
+            }
+        } else {
+            /*
+             * Prior to TLSv1.3 resuming a session always meant using the same
+             * ciphersuite.
+             */
+            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
+                     SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
+            return 0;
+        }
+    }
+    s->s3->tmp.new_cipher = c;
+
+    return 1;
+}
+
+MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
+{
+    PACKET session_id, extpkt;
+    size_t session_id_len;
+    const unsigned char *cipherchars;
+    int hrr = 0;
+    unsigned int compression;
+    unsigned int sversion;
+    unsigned int context;
+    RAW_EXTENSION *extensions = NULL;
+#ifndef OPENSSL_NO_COMP
+    SSL_COMP *comp;
+#endif
+
+    if (!PACKET_get_net_2(pkt, &sversion)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    /* load the server random */
+    if (s->version == TLS1_3_VERSION
+            && sversion == TLS1_2_VERSION
+            && PACKET_remaining(pkt) >= SSL3_RANDOM_SIZE
+            && memcmp(hrrrandom, PACKET_data(pkt), SSL3_RANDOM_SIZE) == 0) {
+        if (s->hello_retry_request != SSL_HRR_NONE) {
+            SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
+                     SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_UNEXPECTED_MESSAGE);
+            goto err;
+        }
+        s->hello_retry_request = SSL_HRR_PENDING;
+        hrr = 1;
+        if (!PACKET_forward(pkt, SSL3_RANDOM_SIZE)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                     SSL_R_LENGTH_MISMATCH);
+            goto err;
+        }
+    } else {
+        if (!PACKET_copy_bytes(pkt, s->s3->server_random, SSL3_RANDOM_SIZE)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                     SSL_R_LENGTH_MISMATCH);
+            goto err;
+        }
+    }
+
+    /* Get the session-id. */
+    if (!PACKET_get_length_prefixed_1(pkt, &session_id)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+    session_id_len = PACKET_remaining(&session_id);
+    if (session_id_len > sizeof(s->session->session_id)
+        || session_id_len > SSL3_SESSION_ID_SIZE) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_SSL3_SESSION_ID_TOO_LONG);
+        goto err;
+    }
+
+    if (!PACKET_get_bytes(pkt, &cipherchars, TLS_CIPHER_LEN)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    if (!PACKET_get_1(pkt, &compression)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    /* TLS extensions */
+    if (PACKET_remaining(pkt) == 0 && !hrr) {
+        PACKET_null_init(&extpkt);
+    } else if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
+               || PACKET_remaining(pkt) != 0) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_BAD_LENGTH);
+        goto err;
+    }
+
+    if (!hrr) {
+        if (!tls_collect_extensions(s, &extpkt,
+                                    SSL_EXT_TLS1_2_SERVER_HELLO
+                                    | SSL_EXT_TLS1_3_SERVER_HELLO,
+                                    &extensions, NULL, 1)) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+
+        if (!ssl_choose_client_version(s, sversion, extensions)) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+    }
+
+    if (SSL_IS_TLS13(s) || hrr) {
+        if (compression != 0) {
+            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+                     SSL_F_TLS_PROCESS_SERVER_HELLO,
+                     SSL_R_INVALID_COMPRESSION_ALGORITHM);
+            goto err;
+        }
+
+        if (session_id_len != s->tmp_session_id_len
+                || memcmp(PACKET_data(&session_id), s->tmp_session_id,
+                          session_id_len) != 0) {
+            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+                     SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_INVALID_SESSION_ID);
+            goto err;
+        }
+    }
+
+    if (hrr) {
+        if (!set_client_ciphersuite(s, cipherchars)) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+
+        return tls_process_as_hello_retry_request(s, &extpkt);
+    }
+
+    /*
+     * Now we have chosen the version we need to check again that the extensions
+     * are appropriate for this version.
+     */
+    context = SSL_IS_TLS13(s) ? SSL_EXT_TLS1_3_SERVER_HELLO
+                              : SSL_EXT_TLS1_2_SERVER_HELLO;
+    if (!tls_validate_all_contexts(s, context, extensions)) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_BAD_EXTENSION);
+        goto err;
+    }
+
+    s->hit = 0;
+
+    if (SSL_IS_TLS13(s)) {
+        /*
+         * In TLSv1.3 a ServerHello message signals a key change so the end of
+         * the message must be on a record boundary.
+         */
+        if (RECORD_LAYER_processed_read_pending(&s->rlayer)) {
+            SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
+                     SSL_F_TLS_PROCESS_SERVER_HELLO,
+                     SSL_R_NOT_ON_RECORD_BOUNDARY);
+            goto err;
+        }
+
+        /* This will set s->hit if we are resuming */
+        if (!tls_parse_extension(s, TLSEXT_IDX_psk,
+                                 SSL_EXT_TLS1_3_SERVER_HELLO,
+                                 extensions, NULL, 0)) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+    } else {
+        /*
+         * Check if we can resume the session based on external pre-shared
+         * secret. EAP-FAST (RFC 4851) supports two types of session resumption.
+         * Resumption based on server-side state works with session IDs.
+         * Resumption based on pre-shared Protected Access Credentials (PACs)
+         * works by overriding the SessionTicket extension at the application
+         * layer, and does not send a session ID. (We do not know whether
+         * EAP-FAST servers would honour the session ID.) Therefore, the session
+         * ID alone is not a reliable indicator of session resumption, so we
+         * first check if 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->ext.session_secret_cb != NULL && s->session->ext.tick) {
+            const SSL_CIPHER *pref_cipher = NULL;
+            /*
+             * 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->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, 0);
+            } else {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_TLS_PROCESS_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
+                goto err;
+            }
+        }
+
+        if (session_id_len != 0
+                && session_id_len == s->session->session_id_length
+                && memcmp(PACKET_data(&session_id), s->session->session_id,
+                          session_id_len) == 0)
+            s->hit = 1;
+    }
+
+    if (s->hit) {
+        if (s->sid_ctx_length != s->session->sid_ctx_length
+                || memcmp(s->session->sid_ctx, s->sid_ctx, s->sid_ctx_length)) {
+            /* actually a client application bug */
+            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+                     SSL_F_TLS_PROCESS_SERVER_HELLO,
+                     SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
+            goto err;
+        }
+    } else {
+        /*
+         * If we were trying for session-id reuse but the server
+         * didn't resume, make a new SSL_SESSION.
+         * In the case of EAP-FAST and PAC, we do not send a session ID,
+         * so the PAC-based session secret is always preserved. It'll be
+         * overwritten if the server refuses resumption.
+         */
+        if (s->session->session_id_length > 0) {
+            tsan_counter(&s->session_ctx->stats.sess_miss);
+            if (!ssl_get_new_session(s, 0)) {
+                /* SSLfatal() already called */
+                goto err;
+            }
+        }
+
+        s->session->ssl_version = s->version;
+        /*
+         * In TLSv1.2 and below we save the session id we were sent so we can
+         * resume it later. In TLSv1.3 the session id we were sent is just an
+         * echo of what we originally sent in the ClientHello and should not be
+         * used for resumption.
+         */
+        if (!SSL_IS_TLS13(s)) {
+            s->session->session_id_length = session_id_len;
+            /* session_id_len could be 0 */
+            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 */
+    if (s->version != s->session->ssl_version) {
+        SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_SSL_SESSION_VERSION_MISMATCH);
+        goto err;
+    }
+    /*
+     * Now that we know the version, update the check to see if it's an allowed
+     * version.
+     */
+    s->s3->tmp.min_ver = s->version;
+    s->s3->tmp.max_ver = s->version;
+
+    if (!set_client_ciphersuite(s, cipherchars)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+#ifdef OPENSSL_NO_COMP
+    if (compression != 0) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
+        goto err;
+    }
+    /*
+     * If compression is disabled we'd better not try to resume a session
+     * using compression.
+     */
+    if (s->session->compress_meth != 0) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_INCONSISTENT_COMPRESSION);
+        goto err;
+    }
+#else
+    if (s->hit && compression != s->session->compress_meth) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_OLD_SESSION_COMPRESSION_ALGORITHM_NOT_RETURNED);
+        goto err;
+    }
+    if (compression == 0)
+        comp = NULL;
+    else if (!ssl_allow_compression(s)) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_COMPRESSION_DISABLED);
+        goto err;
+    } else {
+        comp = ssl3_comp_find(s->ctx->comp_methods, compression);
+    }
+
+    if (compression != 0 && comp == NULL) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                 SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
+        goto err;
+    } else {
+        s->s3->tmp.new_compression = comp;
+    }
+#endif
+
+    if (!tls_parse_all_extensions(s, context, extensions, NULL, 0, 1)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+#ifndef OPENSSL_NO_SCTP
+    if (SSL_IS_DTLS(s) && s->hit) {
+        unsigned char sctpauthkey[64];
+        char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
+        size_t labellen;
+
+        /*
+         * Add new shared key for SCTP-Auth, will be ignored if
+         * no SCTP used.
+         */
+        memcpy(labelbuffer, DTLS1_SCTP_AUTH_LABEL,
+               sizeof(DTLS1_SCTP_AUTH_LABEL));
+
+        /* Don't include the terminating zero. */
+        labellen = sizeof(labelbuffer) - 1;
+        if (s->mode & SSL_MODE_DTLS_SCTP_LABEL_LENGTH_BUG)
+            labellen += 1;
+
+        if (SSL_export_keying_material(s, sctpauthkey,
+                                       sizeof(sctpauthkey),
+                                       labelbuffer,
+                                       labellen, NULL, 0, 0) <= 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
+                     ERR_R_INTERNAL_ERROR);
+            goto err;
+        }
+
+        BIO_ctrl(SSL_get_wbio(s),
+                 BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
+                 sizeof(sctpauthkey), sctpauthkey);
+    }
+#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_READ))) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    OPENSSL_free(extensions);
+    return MSG_PROCESS_CONTINUE_READING;
+ err:
+    OPENSSL_free(extensions);
+    return MSG_PROCESS_ERROR;
+}
+
+static MSG_PROCESS_RETURN tls_process_as_hello_retry_request(SSL *s,
+                                                             PACKET *extpkt)
+{
+    RAW_EXTENSION *extensions = NULL;
+
+    /*
+     * If we were sending early_data then the enc_write_ctx is now invalid and
+     * should not be used.
+     */
+    EVP_CIPHER_CTX_free(s->enc_write_ctx);
+    s->enc_write_ctx = NULL;
+
+    if (!tls_collect_extensions(s, extpkt, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
+                                &extensions, NULL, 1)
+            || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
+                                         extensions, NULL, 0, 1)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    OPENSSL_free(extensions);
+    extensions = NULL;
+
+    if (s->ext.tls13_cookie_len == 0
+#if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
+        && s->s3->tmp.pkey != NULL
+#endif
+        ) {
+        /*
+         * We didn't receive a cookie or a new key_share so the next
+         * ClientHello will not change
+         */
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+                 SSL_F_TLS_PROCESS_AS_HELLO_RETRY_REQUEST,
+                 SSL_R_NO_CHANGE_FOLLOWING_HRR);
+        goto err;
+    }
+
+    /*
+     * Re-initialise the Transcript Hash. We're going to prepopulate it with
+     * a synthetic message_hash in place of ClientHello1.
+     */
+    if (!create_synthetic_message_hash(s, NULL, 0, NULL, 0)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    /*
+     * Add this message to the Transcript Hash. Normally this is done
+     * automatically prior to the message processing stage. However due to the
+     * need to create the synthetic message hash, we defer that step until now
+     * for HRR messages.
+     */
+    if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
+                                s->init_num + SSL3_HM_HEADER_LENGTH)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    return MSG_PROCESS_FINISHED_READING;
+ err:
+    OPENSSL_free(extensions);
+    return MSG_PROCESS_ERROR;
+}
+
+MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
+{
+    int i;
+    MSG_PROCESS_RETURN ret = MSG_PROCESS_ERROR;
+    unsigned long cert_list_len, cert_len;
+    X509 *x = NULL;
+    const unsigned char *certstart, *certbytes;
+    STACK_OF(X509) *sk = NULL;
+    EVP_PKEY *pkey = NULL;
+    size_t chainidx, certidx;
+    unsigned int context = 0;
+    const SSL_CERT_LOOKUP *clu;
+
+    if ((sk = sk_X509_new_null()) == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    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
+            || PACKET_remaining(pkt) == 0) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+    for (chainidx = 0; PACKET_remaining(pkt); chainidx++) {
+        if (!PACKET_get_net_3(pkt, &cert_len)
+            || !PACKET_get_bytes(pkt, &certbytes, cert_len)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR,
+                     SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                     SSL_R_CERT_LENGTH_MISMATCH);
+            goto err;
+        }
+
+        certstart = certbytes;
+        x = d2i_X509(NULL, (const unsigned char **)&certbytes, cert_len);
+        if (x == NULL) {
+            SSLfatal(s, SSL_AD_BAD_CERTIFICATE,
+                     SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, ERR_R_ASN1_LIB);
+            goto err;
+        }
+        if (certbytes != (certstart + cert_len)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR,
+                     SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                     SSL_R_CERT_LENGTH_MISMATCH);
+            goto err;
+        }
+
+        if (SSL_IS_TLS13(s)) {
+            RAW_EXTENSION *rawexts = NULL;
+            PACKET extensions;
+
+            if (!PACKET_get_length_prefixed_2(pkt, &extensions)) {
+                SSLfatal(s, SSL_AD_DECODE_ERROR,
+                         SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                         SSL_R_BAD_LENGTH);
+                goto err;
+            }
+            if (!tls_collect_extensions(s, &extensions,
+                                        SSL_EXT_TLS1_3_CERTIFICATE, &rawexts,
+                                        NULL, chainidx == 0)
+                || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE,
+                                             rawexts, x, chainidx,
+                                             PACKET_remaining(pkt) == 0)) {
+                OPENSSL_free(rawexts);
+                /* SSLfatal already called */
+                goto err;
+            }
+            OPENSSL_free(rawexts);
+        }
+
+        if (!sk_X509_push(sk, x)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                     ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+        x = NULL;
+    }
+
+    i = ssl_verify_cert_chain(s, sk);
+    /*
+     * 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) {
+        SSLfatal(s, ssl_x509err2alert(s->verify_result),
+                 SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                 SSL_R_CERTIFICATE_VERIFY_FAILED);
+        goto err;
+    }
+    ERR_clear_error();          /* but we keep s->verify_result */
+    if (i > 1) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
+                 SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, i);
+        goto err;
+    }
+
+    s->session->peer_chain = sk;
+    /*
+     * Inconsistency alert: cert_chain does include the peer's certificate,
+     * which we don't include in statem_srvr.c
+     */
+    x = sk_X509_value(sk, 0);
+    sk = NULL;
+
+    pkey = X509_get0_pubkey(x);
+
+    if (pkey == NULL || EVP_PKEY_missing_parameters(pkey)) {
+        x = NULL;
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                 SSL_R_UNABLE_TO_FIND_PUBLIC_KEY_PARAMETERS);
+        goto err;
+    }
+
+    if ((clu = ssl_cert_lookup_by_pkey(pkey, &certidx)) == NULL) {
+        x = NULL;
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+                 SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                 SSL_R_UNKNOWN_CERTIFICATE_TYPE);
+        goto err;
+    }
+    /*
+     * Check certificate type is consistent with ciphersuite. For TLS 1.3
+     * skip check since TLS 1.3 ciphersuites can be used with any certificate
+     * type.
+     */
+    if (!SSL_IS_TLS13(s)) {
+        if ((clu->amask & s->s3->tmp.new_cipher->algorithm_auth) == 0) {
+            x = NULL;
+            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+                     SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
+                     SSL_R_WRONG_CERTIFICATE_TYPE);
+            goto err;
+        }
+    }
+
+    X509_free(s->session->peer);
+    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)) {
+        /* SSLfatal() already called */;
+        goto err;
+    }
+
+    ret = MSG_PROCESS_CONTINUE_READING;
+
+ err:
+    X509_free(x);
+    sk_X509_pop_free(sk, X509_free);
+    return ret;
+}
+
+static int tls_process_ske_psk_preamble(SSL *s, PACKET *pkt)
+{
+#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)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, 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) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
+                 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)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    return 1;
+#else
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+static int tls_process_ske_srp(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
+{
+#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)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
+                 SSL_R_LENGTH_MISMATCH);
+        return 0;
+    }
+
+    /* 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) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
+                 ERR_R_BN_LIB);
+        return 0;
+    }
+
+    if (!srp_verify_server_param(s)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    /* 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
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+static int tls_process_ske_dhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
+{
+#ifndef OPENSSL_NO_DH
+    PACKET prime, generator, pub_key;
+    EVP_PKEY *peer_tmp = NULL;
+
+    DH *dh = NULL;
+    BIGNUM *p = NULL, *g = NULL, *bnpub_key = NULL;
+
+    int check_bits = 0;
+
+    if (!PACKET_get_length_prefixed_2(pkt, &prime)
+        || !PACKET_get_length_prefixed_2(pkt, &generator)
+        || !PACKET_get_length_prefixed_2(pkt, &pub_key)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
+                 SSL_R_LENGTH_MISMATCH);
+        return 0;
+    }
+
+    peer_tmp = EVP_PKEY_new();
+    dh = DH_new();
+
+    if (peer_tmp == NULL || dh == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    /* 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) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
+                 ERR_R_BN_LIB);
+        goto err;
+    }
+
+    /* test non-zero pubkey */
+    if (BN_is_zero(bnpub_key)) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_DHE,
+                 SSL_R_BAD_DH_VALUE);
+        goto err;
+    }
+
+    if (!DH_set0_pqg(dh, p, NULL, g)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
+                 ERR_R_BN_LIB);
+        goto err;
+    }
+    p = g = NULL;
+
+    if (DH_check_params(dh, &check_bits) == 0 || check_bits != 0) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_DHE,
+                 SSL_R_BAD_DH_VALUE);
+        goto err;
+    }
+
+    if (!DH_set0_key(dh, bnpub_key, NULL)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
+                 ERR_R_BN_LIB);
+        goto err;
+    }
+    bnpub_key = NULL;
+
+    if (EVP_PKEY_assign_DH(peer_tmp, dh) == 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
+                 ERR_R_EVP_LIB);
+        goto err;
+    }
+    dh = NULL;
+
+    if (!ssl_security(s, SSL_SECOP_TMP_DH, EVP_PKEY_security_bits(peer_tmp),
+                      0, peer_tmp)) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PROCESS_SKE_DHE,
+                 SSL_R_DH_KEY_TOO_SMALL);
+        goto err;
+    }
+
+    s->s3->peer_tmp = peer_tmp;
+
+    /*
+     * 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. */
+
+    return 1;
+
+ err:
+    BN_free(p);
+    BN_free(g);
+    BN_free(bnpub_key);
+    DH_free(dh);
+    EVP_PKEY_free(peer_tmp);
+
+    return 0;
+#else
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+static int tls_process_ske_ecdhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
+{
+#ifndef OPENSSL_NO_EC
+    PACKET encoded_pt;
+    unsigned int curve_type, curve_id;
+
+    /*
+     * Extract elliptic curve parameters and the server's ephemeral ECDH
+     * public key. We only support named (not generic) curves and
+     * ECParameters in this case is just three bytes.
+     */
+    if (!PACKET_get_1(pkt, &curve_type) || !PACKET_get_net_2(pkt, &curve_id)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
+                 SSL_R_LENGTH_TOO_SHORT);
+        return 0;
+    }
+    /*
+     * Check curve is named curve type and one of our preferences, if not
+     * server has sent an invalid curve.
+     */
+    if (curve_type != NAMED_CURVE_TYPE
+            || !tls1_check_group_id(s, curve_id, 1)) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_ECDHE,
+                 SSL_R_WRONG_CURVE);
+        return 0;
+    }
+
+    if ((s->s3->peer_tmp = ssl_generate_param_group(curve_id)) == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
+                 SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
+        return 0;
+    }
+
+    if (!PACKET_get_length_prefixed_1(pkt, &encoded_pt)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
+                 SSL_R_LENGTH_MISMATCH);
+        return 0;
+    }
+
+    if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
+                                        PACKET_data(&encoded_pt),
+                                        PACKET_remaining(&encoded_pt))) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, 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 (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
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
+{
+    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)) {
+            /* SSLfatal() already called */
+            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)) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+    } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
+        if (!tls_process_ske_dhe(s, pkt, &pkey)) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+    } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
+        if (!tls_process_ske_ecdhe(s, pkt, &pkey)) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+    } else if (alg_k) {
+        SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                 SSL_R_UNEXPECTED_MESSAGE);
+        goto err;
+    }
+
+    /* if it was signed, check the signature */
+    if (pkey != NULL) {
+        PACKET params;
+        int maxsig;
+        const EVP_MD *md = NULL;
+        unsigned char *tbs;
+        size_t tbslen;
+        int rv;
+
+        /*
+         * |pkt| now points to the beginning of the signature, so the difference
+         * equals the length of the parameters.
+         */
+        if (!PACKET_get_sub_packet(&save_param_start, &params,
+                                   PACKET_remaining(&save_param_start) -
+                                   PACKET_remaining(pkt))) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                     ERR_R_INTERNAL_ERROR);
+            goto err;
+        }
+
+        if (SSL_USE_SIGALGS(s)) {
+            unsigned int sigalg;
+
+            if (!PACKET_get_net_2(pkt, &sigalg)) {
+                SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                         SSL_R_LENGTH_TOO_SHORT);
+                goto err;
+            }
+            if (tls12_check_peer_sigalg(s, sigalg, pkey) <=0) {
+                /* SSLfatal() already called */
+                goto err;
+            }
+        } else if (!tls1_set_peer_legacy_sigalg(s, pkey)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                     ERR_R_INTERNAL_ERROR);
+            goto err;
+        }
+
+        if (!tls1_lookup_md(s->s3->tmp.peer_sigalg, &md)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                     ERR_R_INTERNAL_ERROR);
+            goto err;
+        }
+#ifdef SSL_DEBUG
+        if (SSL_USE_SIGALGS(s))
+            fprintf(stderr, "USING TLSv1.2 HASH %s\n",
+                    md == NULL ? "n/a" : EVP_MD_name(md));
+#endif
+
+        if (!PACKET_get_length_prefixed_2(pkt, &signature)
+            || PACKET_remaining(pkt) != 0) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                     SSL_R_LENGTH_MISMATCH);
+            goto err;
+        }
+        maxsig = EVP_PKEY_size(pkey);
+        if (maxsig < 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                     ERR_R_INTERNAL_ERROR);
+            goto err;
+        }
+
+        /*
+         * Check signature length
+         */
+        if (PACKET_remaining(&signature) > (size_t)maxsig) {
+            /* wrong packet length */
+            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                   SSL_R_WRONG_SIGNATURE_LENGTH);
+            goto err;
+        }
+
+        md_ctx = EVP_MD_CTX_new();
+        if (md_ctx == NULL) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                     ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+
+        if (EVP_DigestVerifyInit(md_ctx, &pctx, md, NULL, pkey) <= 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                     ERR_R_EVP_LIB);
+            goto err;
+        }
+        if (SSL_USE_PSS(s)) {
+            if (EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) <= 0
+                || EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx,
+                                                RSA_PSS_SALTLEN_DIGEST) <= 0) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_EVP_LIB);
+                goto err;
+            }
+        }
+        tbslen = construct_key_exchange_tbs(s, &tbs, PACKET_data(&params),
+                                            PACKET_remaining(&params));
+        if (tbslen == 0) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+
+        rv = EVP_DigestVerify(md_ctx, PACKET_data(&signature),
+                              PACKET_remaining(&signature), tbs, tbslen);
+        OPENSSL_free(tbs);
+        if (rv <= 0) {
+            SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                     SSL_R_BAD_SIGNATURE);
+            goto err;
+        }
+        EVP_MD_CTX_free(md_ctx);
+        md_ctx = NULL;
+    } else {
+        /* aNULL, aSRP or PSK do not need public keys */
+        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)) {
+                SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                         SSL_R_BAD_DATA);
+            }
+            /* else this shouldn't happen, SSLfatal() already called */
+            goto err;
+        }
+        /* still data left over */
+        if (PACKET_remaining(pkt) != 0) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
+                     SSL_R_EXTRA_DATA_IN_MESSAGE);
+            goto err;
+        }
+    }
+
+    return MSG_PROCESS_CONTINUE_READING;
+ err:
+    EVP_MD_CTX_free(md_ctx);
+    return MSG_PROCESS_ERROR;
+}
+
+MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
+{
+    size_t i;
+
+    /* Clear certificate validity flags */
+    for (i = 0; i < SSL_PKEY_NUM; i++)
+        s->s3->tmp.valid_flags[i] = 0;
+
+    if (SSL_IS_TLS13(s)) {
+        PACKET reqctx, extensions;
+        RAW_EXTENSION *rawexts = NULL;
+
+        if ((s->shutdown & SSL_SENT_SHUTDOWN) != 0) {
+            /*
+             * We already sent close_notify. This can only happen in TLSv1.3
+             * post-handshake messages. We can't reasonably respond to this, so
+             * we just ignore it
+             */
+            return MSG_PROCESS_FINISHED_READING;
+        }
+
+        /* Free and zero certificate types: it is not present in TLS 1.3 */
+        OPENSSL_free(s->s3->tmp.ctype);
+        s->s3->tmp.ctype = NULL;
+        s->s3->tmp.ctype_len = 0;
+        OPENSSL_free(s->pha_context);
+        s->pha_context = NULL;
+        s->pha_context_len = 0;
+
+        if (!PACKET_get_length_prefixed_1(pkt, &reqctx) ||
+            !PACKET_memdup(&reqctx, &s->pha_context, &s->pha_context_len)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR,
+                     SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
+                     SSL_R_LENGTH_MISMATCH);
+            return MSG_PROCESS_ERROR;
+        }
+
+        if (!PACKET_get_length_prefixed_2(pkt, &extensions)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR,
+                     SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
+                     SSL_R_BAD_LENGTH);
+            return MSG_PROCESS_ERROR;
+        }
+        if (!tls_collect_extensions(s, &extensions,
+                                    SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
+                                    &rawexts, NULL, 1)
+            || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
+                                         rawexts, NULL, 0, 1)) {
+            /* SSLfatal() already called */
+            OPENSSL_free(rawexts);
+            return MSG_PROCESS_ERROR;
+        }
+        OPENSSL_free(rawexts);
+        if (!tls1_process_sigalgs(s)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
+                     SSL_R_BAD_LENGTH);
+            return MSG_PROCESS_ERROR;
+        }
+    } else {
+        PACKET ctypes;
+
+        /* get the certificate types */
+        if (!PACKET_get_length_prefixed_1(pkt, &ctypes)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR,
+                     SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
+                     SSL_R_LENGTH_MISMATCH);
+            return MSG_PROCESS_ERROR;
+        }
+
+        if (!PACKET_memdup(&ctypes, &s->s3->tmp.ctype, &s->s3->tmp.ctype_len)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
+                     ERR_R_INTERNAL_ERROR);
+            return MSG_PROCESS_ERROR;
+        }
+
+        if (SSL_USE_SIGALGS(s)) {
+            PACKET sigalgs;
+
+            if (!PACKET_get_length_prefixed_2(pkt, &sigalgs)) {
+                SSLfatal(s, SSL_AD_DECODE_ERROR,
+                         SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
+                         SSL_R_LENGTH_MISMATCH);
+                return MSG_PROCESS_ERROR;
+            }
+
+            /*
+             * Despite this being for certificates, preserve compatibility
+             * with pre-TLS 1.3 and use the regular sigalgs field.
+             */
+            if (!tls1_save_sigalgs(s, &sigalgs, 0)) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
+                         SSL_R_SIGNATURE_ALGORITHMS_ERROR);
+                return MSG_PROCESS_ERROR;
+            }
+            if (!tls1_process_sigalgs(s)) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
+                         ERR_R_MALLOC_FAILURE);
+                return MSG_PROCESS_ERROR;
+            }
+        }
+
+        /* get the CA RDNs */
+        if (!parse_ca_names(s, pkt)) {
+            /* SSLfatal() already called */
+            return MSG_PROCESS_ERROR;
+        }
+    }
+
+    if (PACKET_remaining(pkt) != 0) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR,
+                 SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
+                 SSL_R_LENGTH_MISMATCH);
+        return MSG_PROCESS_ERROR;
+    }
+
+    /* we should setup a certificate to return.... */
+    s->s3->tmp.cert_req = 1;
+
+    /*
+     * In TLSv1.3 we don't prepare the client certificate yet. We wait until
+     * after the CertificateVerify message has been received. This is because
+     * in TLSv1.3 the CertificateRequest arrives before the Certificate message
+     * but in TLSv1.2 it is the other way around. We want to make sure that
+     * SSL_get_peer_certificate() returns something sensible in
+     * client_cert_cb.
+     */
+    if (SSL_IS_TLS13(s) && s->post_handshake_auth != SSL_PHA_REQUESTED)
+        return MSG_PROCESS_CONTINUE_READING;
+
+    return MSG_PROCESS_CONTINUE_PROCESSING;
+}
+
+MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
+{
+    unsigned int ticklen;
+    unsigned long ticket_lifetime_hint, age_add = 0;
+    unsigned int sess_len;
+    RAW_EXTENSION *exts = NULL;
+    PACKET nonce;
+
+    PACKET_null_init(&nonce);
+
+    if (!PACKET_get_net_4(pkt, &ticket_lifetime_hint)
+        || (SSL_IS_TLS13(s)
+            && (!PACKET_get_net_4(pkt, &age_add)
+                || !PACKET_get_length_prefixed_1(pkt, &nonce)))
+        || !PACKET_get_net_2(pkt, &ticklen)
+        || (SSL_IS_TLS13(s) ? (ticklen == 0 || PACKET_remaining(pkt) < ticklen)
+                            : PACKET_remaining(pkt) != ticklen)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    /*
+     * 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;
+
+    /*
+     * Sessions must be immutable once they go into the session cache. Otherwise
+     * we can get multi-thread problems. Therefore we don't "update" sessions,
+     * we replace them with a duplicate. In TLSv1.3 we need to do this every
+     * time a NewSessionTicket arrives because those messages arrive
+     * post-handshake and the session may have already gone into the session
+     * cache.
+     */
+    if (SSL_IS_TLS13(s) || s->session->session_id_length > 0) {
+        SSL_SESSION *new_sess;
+
+        /*
+         * We reused an existing session, so we need to replace it with a new
+         * one
+         */
+        if ((new_sess = ssl_session_dup(s->session, 0)) == 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
+                     ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+
+        if ((s->session_ctx->session_cache_mode & SSL_SESS_CACHE_CLIENT) != 0
+                && !SSL_IS_TLS13(s)) {
+            /*
+             * In TLSv1.2 and below the arrival of a new tickets signals that
+             * any old ticket we were using is now out of date, so we remove the
+             * old session from the cache. We carry on if this fails
+             */
+            SSL_CTX_remove_session(s->session_ctx, s->session);
+        }
+
+        SSL_SESSION_free(s->session);
+        s->session = new_sess;
+    }
+
+    /*
+     * Technically the cast to long here is not guaranteed by the C standard -
+     * but we use it elsewhere, so this should be ok.
+     */
+    s->session->time = (long)time(NULL);
+
+    OPENSSL_free(s->session->ext.tick);
+    s->session->ext.tick = NULL;
+    s->session->ext.ticklen = 0;
+
+    s->session->ext.tick = OPENSSL_malloc(ticklen);
+    if (s->session->ext.tick == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+    if (!PACKET_copy_bytes(pkt, s->session->ext.tick, ticklen)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    s->session->ext.tick_lifetime_hint = ticket_lifetime_hint;
+    s->session->ext.tick_age_add = age_add;
+    s->session->ext.ticklen = ticklen;
+
+    if (SSL_IS_TLS13(s)) {
+        PACKET extpkt;
+
+        if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
+                || PACKET_remaining(pkt) != 0) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR,
+                     SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
+                     SSL_R_LENGTH_MISMATCH);
+            goto err;
+        }
+
+        if (!tls_collect_extensions(s, &extpkt,
+                                    SSL_EXT_TLS1_3_NEW_SESSION_TICKET, &exts,
+                                    NULL, 1)
+                || !tls_parse_all_extensions(s,
+                                             SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
+                                             exts, NULL, 0, 1)) {
+            /* SSLfatal() already called */
+            goto 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
+     * ServerHello. This allows the normal client session ID matching to work
+     * and we know much earlier that the ticket has been accepted. The
+     * other way is to set zero length session ID when the ticket is
+     * presented and rely on the handshake to determine session resumption.
+     * We choose the former approach because this fits in with assumptions
+     * elsewhere in OpenSSL. The session ID is set to the SHA256 (or SHA1 is
+     * SHA256 is disabled) hash of the ticket.
+     */
+    /*
+     * 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)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
+                 ERR_R_EVP_LIB);
+        goto err;
+    }
+    s->session->session_id_length = sess_len;
+    s->session->not_resumable = 0;
+
+    /* This is a standalone message in TLSv1.3, so there is no more to read */
+    if (SSL_IS_TLS13(s)) {
+        const EVP_MD *md = ssl_handshake_md(s);
+        int hashleni = EVP_MD_size(md);
+        size_t hashlen;
+        static const unsigned char nonce_label[] = "resumption";
+
+        /* Ensure cast to size_t is safe */
+        if (!ossl_assert(hashleni >= 0)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
+                     ERR_R_INTERNAL_ERROR);
+            goto err;
+        }
+        hashlen = (size_t)hashleni;
+
+        if (!tls13_hkdf_expand(s, md, s->resumption_master_secret,
+                               nonce_label,
+                               sizeof(nonce_label) - 1,
+                               PACKET_data(&nonce),
+                               PACKET_remaining(&nonce),
+                               s->session->master_key,
+                               hashlen, 1)) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+        s->session->master_key_length = hashlen;
+
+        OPENSSL_free(exts);
+        ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
+        return MSG_PROCESS_FINISHED_READING;
+    }
+
+    return MSG_PROCESS_CONTINUE_READING;
+ err:
+    OPENSSL_free(exts);
+    return MSG_PROCESS_ERROR;
+}
+
+/*
+ * 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
+ */
+int tls_process_cert_status_body(SSL *s, PACKET *pkt)
+{
+    size_t resplen;
+    unsigned int type;
+
+    if (!PACKET_get_1(pkt, &type)
+        || type != TLSEXT_STATUSTYPE_ocsp) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
+                 SSL_R_UNSUPPORTED_STATUS_TYPE);
+        return 0;
+    }
+    if (!PACKET_get_net_3_len(pkt, &resplen)
+        || PACKET_remaining(pkt) != resplen) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
+                 SSL_R_LENGTH_MISMATCH);
+        return 0;
+    }
+    s->ext.ocsp.resp = OPENSSL_malloc(resplen);
+    if (s->ext.ocsp.resp == NULL) {
+        s->ext.ocsp.resp_len = 0;
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
+                 ERR_R_MALLOC_FAILURE);
+        return 0;
+    }
+    s->ext.ocsp.resp_len = resplen;
+    if (!PACKET_copy_bytes(pkt, s->ext.ocsp.resp, resplen)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
+                 SSL_R_LENGTH_MISMATCH);
+        return 0;
+    }
+
+    return 1;
+}
+
+
+MSG_PROCESS_RETURN tls_process_cert_status(SSL *s, PACKET *pkt)
+{
+    if (!tls_process_cert_status_body(s, pkt)) {
+        /* SSLfatal() already called */
+        return MSG_PROCESS_ERROR;
+    }
+
+    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)
+{
+    /*
+     * at this point we check that we have the required stuff from
+     * the server
+     */
+    if (!ssl3_check_cert_and_algorithm(s)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    /*
+     * 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->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) {
+            SSLfatal(s, SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE,
+                     SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
+                     SSL_R_INVALID_STATUS_RESPONSE);
+            return 0;
+        }
+        if (ret < 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
+                     SSL_R_OCSP_CALLBACK_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)) {
+            /* SSLfatal() already called */
+            return 0;
+        }
+    }
+#endif
+
+    return 1;
+}
+
+MSG_PROCESS_RETURN tls_process_server_done(SSL *s, PACKET *pkt)
+{
+    if (PACKET_remaining(pkt) > 0) {
+        /* should contain no data */
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_DONE,
+                 SSL_R_LENGTH_MISMATCH);
+        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) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_DONE,
+                     SSL_R_SRP_A_CALC);
+            return MSG_PROCESS_ERROR;
+        }
+    }
+#endif
+
+    if (!tls_process_initial_server_flight(s)) {
+        /* SSLfatal() already called */
+        return MSG_PROCESS_ERROR;
+    }
+
+    return MSG_PROCESS_FINISHED_READING;
+}
+
+static int tls_construct_cke_psk_preamble(SSL *s, WPACKET *pkt)
+{
+#ifndef OPENSSL_NO_PSK
+    int ret = 0;
+    /*
+     * The callback needs PSK_MAX_IDENTITY_LEN + 1 bytes to return a
+     * \0-terminated identity. The last byte is for us for simulating
+     * strnlen.
+     */
+    char identity[PSK_MAX_IDENTITY_LEN + 1];
+    size_t identitylen = 0;
+    unsigned char psk[PSK_MAX_PSK_LEN];
+    unsigned char *tmppsk = NULL;
+    char *tmpidentity = NULL;
+    size_t psklen = 0;
+
+    if (s->psk_client_callback == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
+                 SSL_R_PSK_NO_CLIENT_CB);
+        goto err;
+    }
+
+    memset(identity, 0, sizeof(identity));
+
+    psklen = s->psk_client_callback(s, s->session->psk_identity_hint,
+                                    identity, sizeof(identity) - 1,
+                                    psk, sizeof(psk));
+
+    if (psklen > PSK_MAX_PSK_LEN) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
+                 SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE, ERR_R_INTERNAL_ERROR);
+        psklen = PSK_MAX_PSK_LEN;   /* Avoid overrunning the array on cleanse */
+        goto err;
+    } else if (psklen == 0) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
+                 SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
+                 SSL_R_PSK_IDENTITY_NOT_FOUND);
+        goto err;
+    }
+
+    identitylen = strlen(identity);
+    if (identitylen > PSK_MAX_IDENTITY_LEN) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    tmppsk = OPENSSL_memdup(psk, psklen);
+    tmpidentity = OPENSSL_strdup(identity);
+    if (tmppsk == NULL || tmpidentity == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    OPENSSL_free(s->s3->tmp.psk);
+    s->s3->tmp.psk = tmppsk;
+    s->s3->tmp.psklen = psklen;
+    tmppsk = NULL;
+    OPENSSL_free(s->session->psk_identity);
+    s->session->psk_identity = tmpidentity;
+    tmpidentity = NULL;
+
+    if (!WPACKET_sub_memcpy_u16(pkt, identity, identitylen))  {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    ret = 1;
+
+ err:
+    OPENSSL_cleanse(psk, psklen);
+    OPENSSL_cleanse(identity, sizeof(identity));
+    OPENSSL_clear_free(tmppsk, psklen);
+    OPENSSL_clear_free(tmpidentity, identitylen);
+
+    return ret;
+#else
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+static int tls_construct_cke_rsa(SSL *s, WPACKET *pkt)
+{
+#ifndef OPENSSL_NO_RSA
+    unsigned char *encdata = NULL;
+    EVP_PKEY *pkey = NULL;
+    EVP_PKEY_CTX *pctx = NULL;
+    size_t enclen;
+    unsigned char *pms = NULL;
+    size_t pmslen = 0;
+
+    if (s->session->peer == NULL) {
+        /*
+         * We should always have a server certificate with SSL_kRSA.
+         */
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    pkey = X509_get0_pubkey(s->session->peer);
+    if (EVP_PKEY_get0_RSA(pkey) == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    pmslen = SSL_MAX_MASTER_KEY_LENGTH;
+    pms = OPENSSL_malloc(pmslen);
+    if (pms == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
+                 ERR_R_MALLOC_FAILURE);
+        return 0;
+    }
+
+    pms[0] = s->client_version >> 8;
+    pms[1] = s->client_version & 0xff;
+    /* TODO(size_t): Convert this function */
+    if (RAND_bytes(pms + 2, (int)(pmslen - 2)) <= 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    /* Fix buf for TLS and beyond */
+    if (s->version > SSL3_VERSION && !WPACKET_start_sub_packet_u16(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 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) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
+                 ERR_R_EVP_LIB);
+        goto err;
+    }
+    if (!WPACKET_allocate_bytes(pkt, enclen, &encdata)
+            || EVP_PKEY_encrypt(pctx, encdata, &enclen, pms, pmslen) <= 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
+                 SSL_R_BAD_RSA_ENCRYPT);
+        goto err;
+    }
+    EVP_PKEY_CTX_free(pctx);
+    pctx = NULL;
+
+    /* Fix buf for TLS and beyond */
+    if (s->version > SSL3_VERSION && !WPACKET_close(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    /* Log the premaster secret, if logging is enabled. */
+    if (!ssl_log_rsa_client_key_exchange(s, encdata, enclen, pms, pmslen)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    s->s3->tmp.pms = pms;
+    s->s3->tmp.pmslen = pmslen;
+
+    return 1;
+ err:
+    OPENSSL_clear_free(pms, pmslen);
+    EVP_PKEY_CTX_free(pctx);
+
+    return 0;
+#else
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+static int tls_construct_cke_dhe(SSL *s, WPACKET *pkt)
+{
+#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) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    ckey = ssl_generate_pkey(skey);
+    if (ckey == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    dh_clnt = EVP_PKEY_get0_DH(ckey);
+
+    if (dh_clnt == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    if (ssl_derive(s, ckey, skey, 0) == 0) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    /* send off the data */
+    DH_get0_key(dh_clnt, &pub_key, NULL);
+    if (!WPACKET_sub_allocate_bytes_u16(pkt, BN_num_bytes(pub_key),
+                                        &keybytes)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    BN_bn2bin(pub_key, keybytes);
+    EVP_PKEY_free(ckey);
+
+    return 1;
+ err:
+    EVP_PKEY_free(ckey);
+    return 0;
+#else
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+static int tls_construct_cke_ecdhe(SSL *s, WPACKET *pkt)
+{
+#ifndef OPENSSL_NO_EC
+    unsigned char *encodedPoint = NULL;
+    size_t encoded_pt_len = 0;
+    EVP_PKEY *ckey = NULL, *skey = NULL;
+    int ret = 0;
+
+    skey = s->s3->peer_tmp;
+    if (skey == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    ckey = ssl_generate_pkey(skey);
+    if (ckey == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    if (ssl_derive(s, ckey, skey, 0) == 0) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    /* Generate encoding of client key */
+    encoded_pt_len = EVP_PKEY_get1_tls_encodedpoint(ckey, &encodedPoint);
+
+    if (encoded_pt_len == 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
+                 ERR_R_EC_LIB);
+        goto err;
+    }
+
+    if (!WPACKET_sub_memcpy_u8(pkt, encodedPoint, encoded_pt_len)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    ret = 1;
+ err:
+    OPENSSL_free(encodedPoint);
+    EVP_PKEY_free(ckey);
+    return ret;
+#else
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+static int tls_construct_cke_gost(SSL *s, WPACKET *pkt)
+{
+#ifndef OPENSSL_NO_GOST
+    /* GOST key exchange message creation */
+    EVP_PKEY_CTX *pkey_ctx = NULL;
+    X509 *peer_cert;
+    size_t msglen;
+    unsigned int md_len;
+    unsigned char shared_ukm[32], tmp[256];
+    EVP_MD_CTX *ukm_hash = NULL;
+    int dgst_nid = NID_id_GostR3411_94;
+    unsigned char *pms = NULL;
+    size_t pmslen = 0;
+
+    if ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aGOST12) != 0)
+        dgst_nid = NID_id_GostR3411_2012_256;
+
+    /*
+     * Get server certificate PKEY and create ctx from it
+     */
+    peer_cert = s->session->peer;
+    if (!peer_cert) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_CONSTRUCT_CKE_GOST,
+               SSL_R_NO_GOST_CERTIFICATE_SENT_BY_PEER);
+        return 0;
+    }
+
+    pkey_ctx = EVP_PKEY_CTX_new(X509_get0_pubkey(peer_cert), NULL);
+    if (pkey_ctx == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
+                 ERR_R_MALLOC_FAILURE);
+        return 0;
+    }
+    /*
+     * If we have send a certificate, and certificate key
+     * parameters match those of server certificate, use
+     * certificate key for key exchange
+     */
+
+    /* Otherwise, generate ephemeral key pair */
+    pmslen = 32;
+    pms = OPENSSL_malloc(pmslen);
+    if (pms == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    if (EVP_PKEY_encrypt_init(pkey_ctx) <= 0
+        /* Generate session key
+         * TODO(size_t): Convert this function
+         */
+        || RAND_bytes(pms, (int)pmslen) <= 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    };
+    /*
+     * 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) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+    EVP_MD_CTX_free(ukm_hash);
+    ukm_hash = NULL;
+    if (EVP_PKEY_CTX_ctrl(pkey_ctx, -1, EVP_PKEY_OP_ENCRYPT,
+                          EVP_PKEY_CTRL_SET_IV, 8, shared_ukm) < 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
+                 SSL_R_LIBRARY_BUG);
+        goto err;
+    }
+    /* Make GOST keytransport blob message */
+    /*
+     * Encapsulate it into sequence
+     */
+    msglen = 255;
+    if (EVP_PKEY_encrypt(pkey_ctx, tmp, &msglen, pms, pmslen) <= 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
+                 SSL_R_LIBRARY_BUG);
+        goto err;
+    }
+
+    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)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 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;
+
+    return 1;
+ err:
+    EVP_PKEY_CTX_free(pkey_ctx);
+    OPENSSL_clear_free(pms, pmslen);
+    EVP_MD_CTX_free(ukm_hash);
+    return 0;
+#else
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+static int tls_construct_cke_srp(SSL *s, WPACKET *pkt)
+{
+#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)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, 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) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
+                 ERR_R_MALLOC_FAILURE);
+        return 0;
+    }
+
+    return 1;
+#else
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
+             ERR_R_INTERNAL_ERROR);
+    return 0;
+#endif
+}
+
+int tls_construct_client_key_exchange(SSL *s, WPACKET *pkt)
+{
+    unsigned long alg_k;
+
+    alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
+
+    /*
+     * All of the construct functions below call SSLfatal() if necessary so
+     * no need to do so here.
+     */
+    if ((alg_k & SSL_PSK)
+        && !tls_construct_cke_psk_preamble(s, pkt))
+        goto err;
+
+    if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {
+        if (!tls_construct_cke_rsa(s, pkt))
+            goto err;
+    } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
+        if (!tls_construct_cke_dhe(s, pkt))
+            goto err;
+    } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
+        if (!tls_construct_cke_ecdhe(s, pkt))
+            goto err;
+    } else if (alg_k & SSL_kGOST) {
+        if (!tls_construct_cke_gost(s, pkt))
+            goto err;
+    } else if (alg_k & SSL_kSRP) {
+        if (!tls_construct_cke_srp(s, pkt))
+            goto err;
+    } else if (!(alg_k & SSL_kPSK)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    return 1;
+ err:
+    OPENSSL_clear_free(s->s3->tmp.pms, s->s3->tmp.pmslen);
+    s->s3->tmp.pms = NULL;
+    s->s3->tmp.pmslen = 0;
+#ifndef OPENSSL_NO_PSK
+    OPENSSL_clear_free(s->s3->tmp.psk, s->s3->tmp.psklen);
+    s->s3->tmp.psk = NULL;
+    s->s3->tmp.psklen = 0;
+#endif
+    return 0;
+}
+
+int tls_client_key_exchange_post_work(SSL *s)
+{
+    unsigned char *pms = NULL;
+    size_t pmslen = 0;
+
+    pms = s->s3->tmp.pms;
+    pmslen = s->s3->tmp.pmslen;
+
+#ifndef OPENSSL_NO_SRP
+    /* Check for SRP */
+    if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
+        if (!srp_generate_client_master_secret(s)) {
+            /* SSLfatal() already called */
+            goto err;
+        }
+        return 1;
+    }
+#endif
+
+    if (pms == NULL && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK, ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+    if (!ssl_generate_master_secret(s, pms, pmslen, 1)) {
+        /* SSLfatal() already called */
+        /* ssl_generate_master_secret frees the pms even on error */
+        pms = NULL;
+        pmslen = 0;
+        goto err;
+    }
+    pms = NULL;
+    pmslen = 0;
+
+#ifndef OPENSSL_NO_SCTP
+    if (SSL_IS_DTLS(s)) {
+        unsigned char sctpauthkey[64];
+        char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
+        size_t labellen;
+
+        /*
+         * Add new shared key for SCTP-Auth, will be ignored if no SCTP
+         * used.
+         */
+        memcpy(labelbuffer, DTLS1_SCTP_AUTH_LABEL,
+               sizeof(DTLS1_SCTP_AUTH_LABEL));
+
+        /* Don't include the terminating zero. */
+        labellen = sizeof(labelbuffer) - 1;
+        if (s->mode & SSL_MODE_DTLS_SCTP_LABEL_LENGTH_BUG)
+            labellen += 1;
+
+        if (SSL_export_keying_material(s, sctpauthkey,
+                                       sizeof(sctpauthkey), labelbuffer,
+                                       labellen, NULL, 0, 0) <= 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK,
+                     ERR_R_INTERNAL_ERROR);
+            goto err;
+        }
+
+        BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
+                 sizeof(sctpauthkey), sctpauthkey);
+    }
+#endif
+
+    return 1;
+ err:
+    OPENSSL_clear_free(pms, pmslen);
+    s->s3->tmp.pms = NULL;
+    s->s3->tmp.pmslen = 0;
+    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
+ * certificates can be used and optionally checks suitability for Suite B.
+ */
+static int ssl3_check_client_certificate(SSL *s)
+{
+    /* If no suitable signature algorithm can't use certificate */
+    if (!tls_choose_sigalg(s, 0) || s->s3->tmp.sigalg == NULL)
+        return 0;
+    /*
+     * If strict mode check suitability of chain before using it. This also
+     * adjusts suite B digest if necessary.
+     */
+    if (s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT &&
+        !tls1_check_chain(s, NULL, NULL, NULL, -2))
+        return 0;
+    return 1;
+}
+
+WORK_STATE tls_prepare_client_certificate(SSL *s, WORK_STATE wst)
+{
+    X509 *x509 = NULL;
+    EVP_PKEY *pkey = NULL;
+    int i;
+
+    if (wst == WORK_MORE_A) {
+        /* Let cert callback update client certificates if required */
+        if (s->cert->cert_cb) {
+            i = s->cert->cert_cb(s, s->cert->cert_cb_arg);
+            if (i < 0) {
+                s->rwstate = SSL_X509_LOOKUP;
+                return WORK_MORE_A;
+            }
+            if (i == 0) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
+                         SSL_R_CALLBACK_FAILED);
+                return WORK_ERROR;
+            }
+            s->rwstate = SSL_NOTHING;
+        }
+        if (ssl3_check_client_certificate(s)) {
+            if (s->post_handshake_auth == SSL_PHA_REQUESTED) {
+                return WORK_FINISHED_STOP;
+            }
+            return WORK_FINISHED_CONTINUE;
+        }
+
+        /* Fall through to WORK_MORE_B */
+        wst = WORK_MORE_B;
+    }
+
+    /* We need to get a client cert */
+    if (wst == WORK_MORE_B) {
+        /*
+         * If we get an error, we need to ssl->rwstate=SSL_X509_LOOKUP;
+         * return(-1); We then get retied later
+         */
+        i = ssl_do_client_cert_cb(s, &x509, &pkey);
+        if (i < 0) {
+            s->rwstate = SSL_X509_LOOKUP;
+            return WORK_MORE_B;
+        }
+        s->rwstate = SSL_NOTHING;
+        if ((i == 1) && (pkey != NULL) && (x509 != NULL)) {
+            if (!SSL_use_certificate(s, x509) || !SSL_use_PrivateKey(s, pkey))
+                i = 0;
+        } else if (i == 1) {
+            i = 0;
+            SSLerr(SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
+                   SSL_R_BAD_DATA_RETURNED_BY_CALLBACK);
+        }
+
+        X509_free(x509);
+        EVP_PKEY_free(pkey);
+        if (i && !ssl3_check_client_certificate(s))
+            i = 0;
+        if (i == 0) {
+            if (s->version == SSL3_VERSION) {
+                s->s3->tmp.cert_req = 0;
+                ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_CERTIFICATE);
+                return WORK_FINISHED_CONTINUE;
+            } else {
+                s->s3->tmp.cert_req = 2;
+                if (!ssl3_digest_cached_records(s, 0)) {
+                    /* SSLfatal() already called */
+                    return WORK_ERROR;
+                }
+            }
+        }
+
+        if (s->post_handshake_auth == SSL_PHA_REQUESTED)
+            return WORK_FINISHED_STOP;
+        return WORK_FINISHED_CONTINUE;
+    }
+
+    /* Shouldn't ever get here */
+    SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
+             ERR_R_INTERNAL_ERROR);
+    return WORK_ERROR;
+}
+
+int tls_construct_client_certificate(SSL *s, WPACKET *pkt)
+{
+    if (SSL_IS_TLS13(s)) {
+        if (s->pha_context == NULL) {
+            /* no context available, add 0-length context */
+            if (!WPACKET_put_bytes_u8(pkt, 0)) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
+                return 0;
+            }
+        } else if (!WPACKET_sub_memcpy_u8(pkt, s->pha_context, s->pha_context_len)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
+            return 0;
+        }
+    }
+    if (!ssl3_output_cert_chain(s, pkt,
+                                (s->s3->tmp.cert_req == 2) ? NULL
+                                                           : s->cert->key)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    if (SSL_IS_TLS13(s)
+            && SSL_IS_FIRST_HANDSHAKE(s)
+            && (!s->method->ssl3_enc->change_cipher_state(s,
+                    SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_WRITE))) {
+        /*
+         * This is a fatal error, which leaves enc_write_ctx in an inconsistent
+         * state and thus ssl3_send_alert may crash.
+         */
+        SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE,
+                 SSL_R_CANNOT_CHANGE_CIPHER);
+        return 0;
+    }
+
+    return 1;
+}
+
+int ssl3_check_cert_and_algorithm(SSL *s)
+{
+    const SSL_CERT_LOOKUP *clu;
+    size_t idx;
+    long alg_k, alg_a;
+
+    alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
+    alg_a = s->s3->tmp.new_cipher->algorithm_auth;
+
+    /* we don't have a certificate */
+    if (!(alg_a & SSL_aCERT))
+        return 1;
+
+    /* This is the passed certificate */
+    clu = ssl_cert_lookup_by_pkey(X509_get0_pubkey(s->session->peer), &idx);
+
+    /* Check certificate is recognised and suitable for cipher */
+    if (clu == NULL || (alg_a & clu->amask) == 0) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
+                 SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
+                 SSL_R_MISSING_SIGNING_CERT);
+        return 0;
+    }
+
+#ifndef OPENSSL_NO_EC
+    if (clu->amask & SSL_aECDSA) {
+        if (ssl_check_srvr_ecc_cert_and_alg(s->session->peer, s))
+            return 1;
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
+                 SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM, SSL_R_BAD_ECC_CERT);
+        return 0;
+    }
+#endif
+#ifndef OPENSSL_NO_RSA
+    if (alg_k & (SSL_kRSA | SSL_kRSAPSK) && idx != SSL_PKEY_RSA) {
+        SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
+                 SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
+                 SSL_R_MISSING_RSA_ENCRYPTING_CERT);
+        return 0;
+    }
+#endif
+#ifndef OPENSSL_NO_DH
+    if ((alg_k & SSL_kDHE) && (s->s3->peer_tmp == NULL)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+#endif
+
+    return 1;
+}
+
+#ifndef OPENSSL_NO_NEXTPROTONEG
+int tls_construct_next_proto(SSL *s, WPACKET *pkt)
+{
+    size_t len, padding_len;
+    unsigned char *padding = NULL;
+
+    len = s->ext.npn_len;
+    padding_len = 32 - ((len + 2) % 32);
+
+    if (!WPACKET_sub_memcpy_u8(pkt, s->ext.npn, len)
+            || !WPACKET_sub_allocate_bytes_u8(pkt, padding_len, &padding)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_NEXT_PROTO,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    memset(padding, 0, padding_len);
+
+    return 1;
+}
+#endif
+
+MSG_PROCESS_RETURN tls_process_hello_req(SSL *s, PACKET *pkt)
+{
+    if (PACKET_remaining(pkt) > 0) {
+        /* should contain no data */
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_HELLO_REQ,
+                 SSL_R_LENGTH_MISMATCH);
+        return MSG_PROCESS_ERROR;
+    }
+
+    if ((s->options & SSL_OP_NO_RENEGOTIATION)) {
+        ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
+        return MSG_PROCESS_FINISHED_READING;
+    }
+
+    /*
+     * This is a historical discrepancy (not in the RFC) 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. Either behaviour is reasonable
+     * but doing one for TLS and another for DTLS is odd.
+     */
+    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)
+{
+    PACKET extensions;
+    RAW_EXTENSION *rawexts = NULL;
+
+    if (!PACKET_as_length_prefixed_2(pkt, &extensions)
+            || PACKET_remaining(pkt) != 0) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_ENCRYPTED_EXTENSIONS,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    if (!tls_collect_extensions(s, &extensions,
+                                SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, &rawexts,
+                                NULL, 1)
+            || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
+                                         rawexts, NULL, 0, 1)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    OPENSSL_free(rawexts);
+    return MSG_PROCESS_CONTINUE_READING;
+
+ err:
+    OPENSSL_free(rawexts);
+    return MSG_PROCESS_ERROR;
+}
+
+int ssl_do_client_cert_cb(SSL *s, X509 **px509, EVP_PKEY **ppkey)
+{
+    int i = 0;
+#ifndef OPENSSL_NO_ENGINE
+    if (s->ctx->client_cert_engine) {
+        i = ENGINE_load_ssl_client_cert(s->ctx->client_cert_engine, s,
+                                        SSL_get_client_CA_list(s),
+                                        px509, ppkey, NULL, NULL, NULL);
+        if (i != 0)
+            return i;
+    }
+#endif
+    if (s->ctx->client_cert_cb)
+        i = s->ctx->client_cert_cb(s, px509, ppkey);
+    return i;
+}
+
+int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, WPACKET *pkt)
+{
+    int i;
+    size_t totlen = 0, len, maxlen, maxverok = 0;
+    int empty_reneg_info_scsv = !s->renegotiate;
+
+    /* Set disabled masks for this session */
+    if (!ssl_set_client_disabled(s)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
+                 SSL_R_NO_PROTOCOLS_AVAILABLE);
+        return 0;
+    }
+
+    if (sk == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+#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, 0))
+            continue;
+
+        if (!s->method->put_cipher_by_char(c, pkt, &len)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
+                     ERR_R_INTERNAL_ERROR);
+            return 0;
+        }
+
+        /* Sanity check that the maximum version we offer has ciphers enabled */
+        if (!maxverok) {
+            if (SSL_IS_DTLS(s)) {
+                if (DTLS_VERSION_GE(c->max_dtls, s->s3->tmp.max_ver)
+                        && DTLS_VERSION_LE(c->min_dtls, s->s3->tmp.max_ver))
+                    maxverok = 1;
+            } else {
+                if (c->max_tls >= s->s3->tmp.max_ver
+                        && c->min_tls <= s->s3->tmp.max_ver)
+                    maxverok = 1;
+            }
+        }
+
+        totlen += len;
+    }
+
+    if (totlen == 0 || !maxverok) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
+                 SSL_R_NO_CIPHERS_AVAILABLE);
+
+        if (!maxverok)
+            ERR_add_error_data(1, "No ciphers enabled for max supported "
+                                  "SSL/TLS version");
+
+        return 0;
+    }
+
+    if (totlen != 0) {
+        if (empty_reneg_info_scsv) {
+            static SSL_CIPHER scsv = {
+                0, NULL, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
+            };
+            if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         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, NULL, SSL3_CK_FALLBACK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
+            };
+            if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
+                return 0;
+            }
+        }
+    }
+
+    return 1;
+}
+
+int tls_construct_end_of_early_data(SSL *s, WPACKET *pkt)
+{
+    if (s->early_data_state != SSL_EARLY_DATA_WRITE_RETRY
+            && s->early_data_state != SSL_EARLY_DATA_FINISHED_WRITING) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_TLS_CONSTRUCT_END_OF_EARLY_DATA,
+                 ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+        return 0;
+    }
+
+    s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
+    return 1;
+}