[Feature][T106]ZXW P56U09 code

Only Configure: Yes
Affected branch: master
Affected module: unknow
Is it affected on both ZXIC and MTK: only ZXIC
Self-test: No
Doc Update: No

Change-Id: I3cbd8b420271eb20c2b40ebe5c78f83059cd42f3
diff --git a/ap/lib/libssl/openssl-1.1.1o/ssl/statem/statem_lib.c b/ap/lib/libssl/openssl-1.1.1o/ssl/statem/statem_lib.c
new file mode 100644
index 0000000..695caab
--- /dev/null
+++ b/ap/lib/libssl/openssl-1.1.1o/ssl/statem/statem_lib.c
@@ -0,0 +1,2441 @@
+/*
+ * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright (c) 2002, Oracle and/or its affiliates. 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 <limits.h>
+#include <string.h>
+#include <stdio.h>
+#include "../ssl_local.h"
+#include "statem_local.h"
+#include "internal/cryptlib.h"
+#include <openssl/buffer.h>
+#include <openssl/objects.h>
+#include <openssl/evp.h>
+#include <openssl/x509.h>
+
+/*
+ * Map error codes to TLS/SSL alart types.
+ */
+typedef struct x509err2alert_st {
+    int x509err;
+    int alert;
+} X509ERR2ALERT;
+
+/* Fixed value used in the ServerHello random field to identify an HRR */
+const unsigned char hrrrandom[] = {
+    0xcf, 0x21, 0xad, 0x74, 0xe5, 0x9a, 0x61, 0x11, 0xbe, 0x1d, 0x8c, 0x02,
+    0x1e, 0x65, 0xb8, 0x91, 0xc2, 0xa2, 0x11, 0x16, 0x7a, 0xbb, 0x8c, 0x5e,
+    0x07, 0x9e, 0x09, 0xe2, 0xc8, 0xa8, 0x33, 0x9c
+};
+
+/*
+ * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
+ * SSL3_RT_CHANGE_CIPHER_SPEC)
+ */
+int ssl3_do_write(SSL *s, int type)
+{
+    int ret;
+    size_t written = 0;
+
+    ret = ssl3_write_bytes(s, type, &s->init_buf->data[s->init_off],
+                           s->init_num, &written);
+    if (ret < 0)
+        return -1;
+    if (type == SSL3_RT_HANDSHAKE)
+        /*
+         * should not be done for 'Hello Request's, but in that case we'll
+         * ignore the result anyway
+         * TLS1.3 KeyUpdate and NewSessionTicket do not need to be added
+         */
+        if (!SSL_IS_TLS13(s) || (s->statem.hand_state != TLS_ST_SW_SESSION_TICKET
+                                 && s->statem.hand_state != TLS_ST_CW_KEY_UPDATE
+                                 && s->statem.hand_state != TLS_ST_SW_KEY_UPDATE))
+            if (!ssl3_finish_mac(s,
+                                 (unsigned char *)&s->init_buf->data[s->init_off],
+                                 written))
+                return -1;
+    if (written == s->init_num) {
+        if (s->msg_callback)
+            s->msg_callback(1, s->version, type, s->init_buf->data,
+                            (size_t)(s->init_off + s->init_num), s,
+                            s->msg_callback_arg);
+        return 1;
+    }
+    s->init_off += written;
+    s->init_num -= written;
+    return 0;
+}
+
+int tls_close_construct_packet(SSL *s, WPACKET *pkt, int htype)
+{
+    size_t msglen;
+
+    if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt))
+            || !WPACKET_get_length(pkt, &msglen)
+            || msglen > INT_MAX)
+        return 0;
+    s->init_num = (int)msglen;
+    s->init_off = 0;
+
+    return 1;
+}
+
+int tls_setup_handshake(SSL *s)
+{
+    if (!ssl3_init_finished_mac(s)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    /* Reset any extension flags */
+    memset(s->ext.extflags, 0, sizeof(s->ext.extflags));
+
+    if (s->server) {
+        STACK_OF(SSL_CIPHER) *ciphers = SSL_get_ciphers(s);
+        int i, ver_min, ver_max, ok = 0;
+
+        /*
+         * Sanity check that the maximum version we accept has ciphers
+         * enabled. For clients we do this check during construction of the
+         * ClientHello.
+         */
+        if (ssl_get_min_max_version(s, &ver_min, &ver_max, NULL) != 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_SETUP_HANDSHAKE,
+                     ERR_R_INTERNAL_ERROR);
+            return 0;
+        }
+        for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
+            const SSL_CIPHER *c = sk_SSL_CIPHER_value(ciphers, i);
+
+            if (SSL_IS_DTLS(s)) {
+                if (DTLS_VERSION_GE(ver_max, c->min_dtls) &&
+                        DTLS_VERSION_LE(ver_max, c->max_dtls))
+                    ok = 1;
+            } else if (ver_max >= c->min_tls && ver_max <= c->max_tls) {
+                ok = 1;
+            }
+            if (ok)
+                break;
+        }
+        if (!ok) {
+            SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_SETUP_HANDSHAKE,
+                     SSL_R_NO_CIPHERS_AVAILABLE);
+            ERR_add_error_data(1, "No ciphers enabled for max supported "
+                                  "SSL/TLS version");
+            return 0;
+        }
+        if (SSL_IS_FIRST_HANDSHAKE(s)) {
+            /* N.B. s->session_ctx == s->ctx here */
+            tsan_counter(&s->session_ctx->stats.sess_accept);
+        } else {
+            /* N.B. s->ctx may not equal s->session_ctx */
+            tsan_counter(&s->ctx->stats.sess_accept_renegotiate);
+
+            s->s3->tmp.cert_request = 0;
+        }
+    } else {
+        if (SSL_IS_FIRST_HANDSHAKE(s))
+            tsan_counter(&s->session_ctx->stats.sess_connect);
+        else
+            tsan_counter(&s->session_ctx->stats.sess_connect_renegotiate);
+
+        /* mark client_random uninitialized */
+        memset(s->s3->client_random, 0, sizeof(s->s3->client_random));
+        s->hit = 0;
+
+        s->s3->tmp.cert_req = 0;
+
+        if (SSL_IS_DTLS(s))
+            s->statem.use_timer = 1;
+    }
+
+    return 1;
+}
+
+/*
+ * Size of the to-be-signed TLS13 data, without the hash size itself:
+ * 64 bytes of value 32, 33 context bytes, 1 byte separator
+ */
+#define TLS13_TBS_START_SIZE            64
+#define TLS13_TBS_PREAMBLE_SIZE         (TLS13_TBS_START_SIZE + 33 + 1)
+
+static int get_cert_verify_tbs_data(SSL *s, unsigned char *tls13tbs,
+                                    void **hdata, size_t *hdatalen)
+{
+#ifdef CHARSET_EBCDIC
+    static const char servercontext[] = { 0x54, 0x4c, 0x53, 0x20, 0x31, 0x2e,
+     0x33, 0x2c, 0x20, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x43, 0x65,
+     0x72, 0x74, 0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x56, 0x65, 0x72,
+     0x69, 0x66, 0x79, 0x00 };
+    static const char clientcontext[] = { 0x54, 0x4c, 0x53, 0x20, 0x31, 0x2e,
+     0x33, 0x2c, 0x20, 0x63, 0x6c, 0x69, 0x65, 0x6e, 0x74, 0x20, 0x43, 0x65,
+     0x72, 0x74, 0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x56, 0x65, 0x72,
+     0x69, 0x66, 0x79, 0x00 };
+#else
+    static const char servercontext[] = "TLS 1.3, server CertificateVerify";
+    static const char clientcontext[] = "TLS 1.3, client CertificateVerify";
+#endif
+    if (SSL_IS_TLS13(s)) {
+        size_t hashlen;
+
+        /* Set the first 64 bytes of to-be-signed data to octet 32 */
+        memset(tls13tbs, 32, TLS13_TBS_START_SIZE);
+        /* This copies the 33 bytes of context plus the 0 separator byte */
+        if (s->statem.hand_state == TLS_ST_CR_CERT_VRFY
+                 || s->statem.hand_state == TLS_ST_SW_CERT_VRFY)
+            strcpy((char *)tls13tbs + TLS13_TBS_START_SIZE, servercontext);
+        else
+            strcpy((char *)tls13tbs + TLS13_TBS_START_SIZE, clientcontext);
+
+        /*
+         * If we're currently reading then we need to use the saved handshake
+         * hash value. We can't use the current handshake hash state because
+         * that includes the CertVerify itself.
+         */
+        if (s->statem.hand_state == TLS_ST_CR_CERT_VRFY
+                || s->statem.hand_state == TLS_ST_SR_CERT_VRFY) {
+            memcpy(tls13tbs + TLS13_TBS_PREAMBLE_SIZE, s->cert_verify_hash,
+                   s->cert_verify_hash_len);
+            hashlen = s->cert_verify_hash_len;
+        } else if (!ssl_handshake_hash(s, tls13tbs + TLS13_TBS_PREAMBLE_SIZE,
+                                       EVP_MAX_MD_SIZE, &hashlen)) {
+            /* SSLfatal() already called */
+            return 0;
+        }
+
+        *hdata = tls13tbs;
+        *hdatalen = TLS13_TBS_PREAMBLE_SIZE + hashlen;
+    } else {
+        size_t retlen;
+        long retlen_l;
+
+        retlen = retlen_l = BIO_get_mem_data(s->s3->handshake_buffer, hdata);
+        if (retlen_l <= 0) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_GET_CERT_VERIFY_TBS_DATA,
+                     ERR_R_INTERNAL_ERROR);
+            return 0;
+        }
+        *hdatalen = retlen;
+    }
+
+    return 1;
+}
+
+int tls_construct_cert_verify(SSL *s, WPACKET *pkt)
+{
+    EVP_PKEY *pkey = NULL;
+    const EVP_MD *md = NULL;
+    EVP_MD_CTX *mctx = NULL;
+    EVP_PKEY_CTX *pctx = NULL;
+    size_t hdatalen = 0, siglen = 0;
+    void *hdata;
+    unsigned char *sig = NULL;
+    unsigned char tls13tbs[TLS13_TBS_PREAMBLE_SIZE + EVP_MAX_MD_SIZE];
+    const SIGALG_LOOKUP *lu = s->s3->tmp.sigalg;
+
+    if (lu == NULL || s->s3->tmp.cert == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_VERIFY,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+    pkey = s->s3->tmp.cert->privatekey;
+
+    if (pkey == NULL || !tls1_lookup_md(lu, &md)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_VERIFY,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    mctx = EVP_MD_CTX_new();
+    if (mctx == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_VERIFY,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    /* Get the data to be signed */
+    if (!get_cert_verify_tbs_data(s, tls13tbs, &hdata, &hdatalen)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    if (SSL_USE_SIGALGS(s) && !WPACKET_put_bytes_u16(pkt, lu->sigalg)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_VERIFY,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+    siglen = EVP_PKEY_size(pkey);
+    sig = OPENSSL_malloc(siglen);
+    if (sig == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_VERIFY,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    if (EVP_DigestSignInit(mctx, &pctx, md, NULL, pkey) <= 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_VERIFY,
+                 ERR_R_EVP_LIB);
+        goto err;
+    }
+
+    if (lu->sig == EVP_PKEY_RSA_PSS) {
+        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_CONSTRUCT_CERT_VERIFY,
+                     ERR_R_EVP_LIB);
+            goto err;
+        }
+    }
+    if (s->version == SSL3_VERSION) {
+        if (EVP_DigestSignUpdate(mctx, hdata, hdatalen) <= 0
+            || !EVP_MD_CTX_ctrl(mctx, EVP_CTRL_SSL3_MASTER_SECRET,
+                                (int)s->session->master_key_length,
+                                s->session->master_key)
+            || EVP_DigestSignFinal(mctx, sig, &siglen) <= 0) {
+
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_VERIFY,
+                     ERR_R_EVP_LIB);
+            goto err;
+        }
+    } else if (EVP_DigestSign(mctx, sig, &siglen, hdata, hdatalen) <= 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_VERIFY,
+                 ERR_R_EVP_LIB);
+        goto err;
+    }
+
+#ifndef OPENSSL_NO_GOST
+    {
+        int pktype = lu->sig;
+
+        if (pktype == NID_id_GostR3410_2001
+            || pktype == NID_id_GostR3410_2012_256
+            || pktype == NID_id_GostR3410_2012_512)
+            BUF_reverse(sig, NULL, siglen);
+    }
+#endif
+
+    if (!WPACKET_sub_memcpy_u16(pkt, sig, siglen)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_VERIFY,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    /* Digest cached records and discard handshake buffer */
+    if (!ssl3_digest_cached_records(s, 0)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+    OPENSSL_free(sig);
+    EVP_MD_CTX_free(mctx);
+    return 1;
+ err:
+    OPENSSL_free(sig);
+    EVP_MD_CTX_free(mctx);
+    return 0;
+}
+
+MSG_PROCESS_RETURN tls_process_cert_verify(SSL *s, PACKET *pkt)
+{
+    EVP_PKEY *pkey = NULL;
+    const unsigned char *data;
+#ifndef OPENSSL_NO_GOST
+    unsigned char *gost_data = NULL;
+#endif
+    MSG_PROCESS_RETURN ret = MSG_PROCESS_ERROR;
+    int j;
+    unsigned int len;
+    X509 *peer;
+    const EVP_MD *md = NULL;
+    size_t hdatalen = 0;
+    void *hdata;
+    unsigned char tls13tbs[TLS13_TBS_PREAMBLE_SIZE + EVP_MAX_MD_SIZE];
+    EVP_MD_CTX *mctx = EVP_MD_CTX_new();
+    EVP_PKEY_CTX *pctx = NULL;
+
+    if (mctx == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+
+    peer = s->session->peer;
+    pkey = X509_get0_pubkey(peer);
+    if (pkey == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                 ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    if (ssl_cert_lookup_by_pkey(pkey, NULL) == NULL) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                 SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE);
+        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_CERT_VERIFY,
+                     SSL_R_BAD_PACKET);
+            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_CERT_VERIFY,
+                     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_CERT_VERIFY,
+                 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
+
+    /* Check for broken implementations of GOST ciphersuites */
+    /*
+     * If key is GOST and len is exactly 64 or 128, it is signature without
+     * length field (CryptoPro implementations at least till TLS 1.2)
+     */
+#ifndef OPENSSL_NO_GOST
+    if (!SSL_USE_SIGALGS(s)
+        && ((PACKET_remaining(pkt) == 64
+             && (EVP_PKEY_id(pkey) == NID_id_GostR3410_2001
+                 || EVP_PKEY_id(pkey) == NID_id_GostR3410_2012_256))
+            || (PACKET_remaining(pkt) == 128
+                && EVP_PKEY_id(pkey) == NID_id_GostR3410_2012_512))) {
+        len = PACKET_remaining(pkt);
+    } else
+#endif
+    if (!PACKET_get_net_2(pkt, &len)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    j = EVP_PKEY_size(pkey);
+    if (((int)len > j) || ((int)PACKET_remaining(pkt) > j)
+        || (PACKET_remaining(pkt) == 0)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                 SSL_R_WRONG_SIGNATURE_SIZE);
+        goto err;
+    }
+    if (!PACKET_get_bytes(pkt, &data, len)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    if (!get_cert_verify_tbs_data(s, tls13tbs, &hdata, &hdatalen)) {
+        /* SSLfatal() already called */
+        goto err;
+    }
+
+#ifdef SSL_DEBUG
+    fprintf(stderr, "Using client verify alg %s\n",
+            md == NULL ? "n/a" : EVP_MD_name(md));
+#endif
+    if (EVP_DigestVerifyInit(mctx, &pctx, md, NULL, pkey) <= 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                 ERR_R_EVP_LIB);
+        goto err;
+    }
+#ifndef OPENSSL_NO_GOST
+    {
+        int pktype = EVP_PKEY_id(pkey);
+        if (pktype == NID_id_GostR3410_2001
+            || pktype == NID_id_GostR3410_2012_256
+            || pktype == NID_id_GostR3410_2012_512) {
+            if ((gost_data = OPENSSL_malloc(len)) == NULL) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                         SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
+                goto err;
+            }
+            BUF_reverse(gost_data, data, len);
+            data = gost_data;
+        }
+    }
+#endif
+
+    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_CERT_VERIFY,
+                     ERR_R_EVP_LIB);
+            goto err;
+        }
+    }
+    if (s->version == SSL3_VERSION) {
+        if (EVP_DigestVerifyUpdate(mctx, hdata, hdatalen) <= 0
+                || !EVP_MD_CTX_ctrl(mctx, EVP_CTRL_SSL3_MASTER_SECRET,
+                                    (int)s->session->master_key_length,
+                                    s->session->master_key)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                     ERR_R_EVP_LIB);
+            goto err;
+        }
+        if (EVP_DigestVerifyFinal(mctx, data, len) <= 0) {
+            SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                     SSL_R_BAD_SIGNATURE);
+            goto err;
+        }
+    } else {
+        j = EVP_DigestVerify(mctx, data, len, hdata, hdatalen);
+        if (j <= 0) {
+            SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_CERT_VERIFY,
+                     SSL_R_BAD_SIGNATURE);
+            goto err;
+        }
+    }
+
+    /*
+     * In TLSv1.3 on the client side we make sure we prepare the client
+     * certificate after the CertVerify instead of when we get the
+     * CertificateRequest. This is because in TLSv1.3 the CertificateRequest
+     * comes *before* the Certificate message. In TLSv1.2 it comes after. We
+     * want to make sure that SSL_get_peer_certificate() will return the actual
+     * server certificate from the client_cert_cb callback.
+     */
+    if (!s->server && SSL_IS_TLS13(s) && s->s3->tmp.cert_req == 1)
+        ret = MSG_PROCESS_CONTINUE_PROCESSING;
+    else
+        ret = MSG_PROCESS_CONTINUE_READING;
+ err:
+    BIO_free(s->s3->handshake_buffer);
+    s->s3->handshake_buffer = NULL;
+    EVP_MD_CTX_free(mctx);
+#ifndef OPENSSL_NO_GOST
+    OPENSSL_free(gost_data);
+#endif
+    return ret;
+}
+
+int tls_construct_finished(SSL *s, WPACKET *pkt)
+{
+    size_t finish_md_len;
+    const char *sender;
+    size_t slen;
+
+    /* This is a real handshake so make sure we clean it up at the end */
+    if (!s->server && s->post_handshake_auth != SSL_PHA_REQUESTED)
+        s->statem.cleanuphand = 1;
+
+    /*
+     * We only change the keys if we didn't already do this when we sent the
+     * client certificate
+     */
+    if (SSL_IS_TLS13(s)
+            && !s->server
+            && s->s3->tmp.cert_req == 0
+            && (!s->method->ssl3_enc->change_cipher_state(s,
+                    SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_WRITE))) {;
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    if (s->server) {
+        sender = s->method->ssl3_enc->server_finished_label;
+        slen = s->method->ssl3_enc->server_finished_label_len;
+    } else {
+        sender = s->method->ssl3_enc->client_finished_label;
+        slen = s->method->ssl3_enc->client_finished_label_len;
+    }
+
+    finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
+                                                          sender, slen,
+                                                          s->s3->tmp.finish_md);
+    if (finish_md_len == 0) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    s->s3->tmp.finish_md_len = finish_md_len;
+
+    if (!WPACKET_memcpy(pkt, s->s3->tmp.finish_md, finish_md_len)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_FINISHED,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    /*
+     * Log the master secret, if logging is enabled. We don't log it for
+     * TLSv1.3: there's a different key schedule for that.
+     */
+    if (!SSL_IS_TLS13(s) && !ssl_log_secret(s, MASTER_SECRET_LABEL,
+                                            s->session->master_key,
+                                            s->session->master_key_length)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    /*
+     * Copy the finished so we can use it for renegotiation checks
+     */
+    if (!ossl_assert(finish_md_len <= EVP_MAX_MD_SIZE)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_FINISHED,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+    if (!s->server) {
+        memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md,
+               finish_md_len);
+        s->s3->previous_client_finished_len = finish_md_len;
+    } else {
+        memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md,
+               finish_md_len);
+        s->s3->previous_server_finished_len = finish_md_len;
+    }
+
+    return 1;
+}
+
+int tls_construct_key_update(SSL *s, WPACKET *pkt)
+{
+    if (!WPACKET_put_bytes_u8(pkt, s->key_update)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_KEY_UPDATE,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    s->key_update = SSL_KEY_UPDATE_NONE;
+    return 1;
+}
+
+MSG_PROCESS_RETURN tls_process_key_update(SSL *s, PACKET *pkt)
+{
+    unsigned int updatetype;
+
+    /*
+     * A KeyUpdate 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_KEY_UPDATE,
+                 SSL_R_NOT_ON_RECORD_BOUNDARY);
+        return MSG_PROCESS_ERROR;
+    }
+
+    if (!PACKET_get_1(pkt, &updatetype)
+            || PACKET_remaining(pkt) != 0) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_UPDATE,
+                 SSL_R_BAD_KEY_UPDATE);
+        return MSG_PROCESS_ERROR;
+    }
+
+    /*
+     * There are only two defined key update types. Fail if we get a value we
+     * didn't recognise.
+     */
+    if (updatetype != SSL_KEY_UPDATE_NOT_REQUESTED
+            && updatetype != SSL_KEY_UPDATE_REQUESTED) {
+        SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_KEY_UPDATE,
+                 SSL_R_BAD_KEY_UPDATE);
+        return MSG_PROCESS_ERROR;
+    }
+
+    /*
+     * If we get a request for us to update our sending keys too then, we need
+     * to additionally send a KeyUpdate message. However that message should
+     * not also request an update (otherwise we get into an infinite loop).
+     */
+    if (updatetype == SSL_KEY_UPDATE_REQUESTED)
+        s->key_update = SSL_KEY_UPDATE_NOT_REQUESTED;
+
+    if (!tls13_update_key(s, 0)) {
+        /* SSLfatal() already called */
+        return MSG_PROCESS_ERROR;
+    }
+
+    return MSG_PROCESS_FINISHED_READING;
+}
+
+/*
+ * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
+ * to far.
+ */
+int ssl3_take_mac(SSL *s)
+{
+    const char *sender;
+    size_t slen;
+
+    if (!s->server) {
+        sender = s->method->ssl3_enc->server_finished_label;
+        slen = s->method->ssl3_enc->server_finished_label_len;
+    } else {
+        sender = s->method->ssl3_enc->client_finished_label;
+        slen = s->method->ssl3_enc->client_finished_label_len;
+    }
+
+    s->s3->tmp.peer_finish_md_len =
+        s->method->ssl3_enc->final_finish_mac(s, sender, slen,
+                                              s->s3->tmp.peer_finish_md);
+
+    if (s->s3->tmp.peer_finish_md_len == 0) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    return 1;
+}
+
+MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt)
+{
+    size_t remain;
+
+    remain = PACKET_remaining(pkt);
+    /*
+     * 'Change Cipher Spec' is just a single byte, which should already have
+     * been consumed by ssl_get_message() so there should be no bytes left,
+     * unless we're using DTLS1_BAD_VER, which has an extra 2 bytes
+     */
+    if (SSL_IS_DTLS(s)) {
+        if ((s->version == DTLS1_BAD_VER
+             && remain != DTLS1_CCS_HEADER_LENGTH + 1)
+            || (s->version != DTLS1_BAD_VER
+                && remain != DTLS1_CCS_HEADER_LENGTH - 1)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR,
+                     SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
+                    SSL_R_BAD_CHANGE_CIPHER_SPEC);
+            return MSG_PROCESS_ERROR;
+        }
+    } else {
+        if (remain != 0) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR,
+                     SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
+                     SSL_R_BAD_CHANGE_CIPHER_SPEC);
+            return MSG_PROCESS_ERROR;
+        }
+    }
+
+    /* Check we have a cipher to change to */
+    if (s->s3->tmp.new_cipher == NULL) {
+        SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
+                 SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY);
+        return MSG_PROCESS_ERROR;
+    }
+
+    s->s3->change_cipher_spec = 1;
+    if (!ssl3_do_change_cipher_spec(s)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
+                 ERR_R_INTERNAL_ERROR);
+        return MSG_PROCESS_ERROR;
+    }
+
+    if (SSL_IS_DTLS(s)) {
+        dtls1_reset_seq_numbers(s, SSL3_CC_READ);
+
+        if (s->version == DTLS1_BAD_VER)
+            s->d1->handshake_read_seq++;
+
+#ifndef OPENSSL_NO_SCTP
+        /*
+         * Remember that a CCS has been received, so that an old key of
+         * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
+         * SCTP is used
+         */
+        BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
+#endif
+    }
+
+    return MSG_PROCESS_CONTINUE_READING;
+}
+
+MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt)
+{
+    size_t md_len;
+
+
+    /* This is a real handshake so make sure we clean it up at the end */
+    if (s->server) {
+        /*
+        * To get this far we must have read encrypted data from the client. We
+        * no longer tolerate unencrypted alerts. This value is ignored if less
+        * than TLSv1.3
+        */
+        s->statem.enc_read_state = ENC_READ_STATE_VALID;
+        if (s->post_handshake_auth != SSL_PHA_REQUESTED)
+            s->statem.cleanuphand = 1;
+        if (SSL_IS_TLS13(s) && !tls13_save_handshake_digest_for_pha(s)) {
+                /* SSLfatal() already called */
+                return MSG_PROCESS_ERROR;
+        }
+    }
+
+    /*
+     * In TLSv1.3 a Finished message signals a key change so the end of the
+     * message must be on a record boundary.
+     */
+    if (SSL_IS_TLS13(s) && RECORD_LAYER_processed_read_pending(&s->rlayer)) {
+        SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_TLS_PROCESS_FINISHED,
+                 SSL_R_NOT_ON_RECORD_BOUNDARY);
+        return MSG_PROCESS_ERROR;
+    }
+
+    /* If this occurs, we have missed a message */
+    if (!SSL_IS_TLS13(s) && !s->s3->change_cipher_spec) {
+        SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_TLS_PROCESS_FINISHED,
+                 SSL_R_GOT_A_FIN_BEFORE_A_CCS);
+        return MSG_PROCESS_ERROR;
+    }
+    s->s3->change_cipher_spec = 0;
+
+    md_len = s->s3->tmp.peer_finish_md_len;
+
+    if (md_len != PACKET_remaining(pkt)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_FINISHED,
+                 SSL_R_BAD_DIGEST_LENGTH);
+        return MSG_PROCESS_ERROR;
+    }
+
+    if (CRYPTO_memcmp(PACKET_data(pkt), s->s3->tmp.peer_finish_md,
+                      md_len) != 0) {
+        SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_FINISHED,
+                 SSL_R_DIGEST_CHECK_FAILED);
+        return MSG_PROCESS_ERROR;
+    }
+
+    /*
+     * Copy the finished so we can use it for renegotiation checks
+     */
+    if (!ossl_assert(md_len <= EVP_MAX_MD_SIZE)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_FINISHED,
+                 ERR_R_INTERNAL_ERROR);
+        return MSG_PROCESS_ERROR;
+    }
+    if (s->server) {
+        memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md,
+               md_len);
+        s->s3->previous_client_finished_len = md_len;
+    } else {
+        memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md,
+               md_len);
+        s->s3->previous_server_finished_len = md_len;
+    }
+
+    /*
+     * In TLS1.3 we also have to change cipher state and do any final processing
+     * of the initial server flight (if we are a client)
+     */
+    if (SSL_IS_TLS13(s)) {
+        if (s->server) {
+            if (s->post_handshake_auth != SSL_PHA_REQUESTED &&
+                    !s->method->ssl3_enc->change_cipher_state(s,
+                    SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_SERVER_READ)) {
+                /* SSLfatal() already called */
+                return MSG_PROCESS_ERROR;
+            }
+        } else {
+            /* TLS 1.3 gets the secret size from the handshake md */
+            size_t dummy;
+            if (!s->method->ssl3_enc->generate_master_secret(s,
+                    s->master_secret, s->handshake_secret, 0,
+                    &dummy)) {
+                /* SSLfatal() already called */
+                return MSG_PROCESS_ERROR;
+            }
+            if (!s->method->ssl3_enc->change_cipher_state(s,
+                    SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_CLIENT_READ)) {
+                /* SSLfatal() already called */
+                return MSG_PROCESS_ERROR;
+            }
+            if (!tls_process_initial_server_flight(s)) {
+                /* SSLfatal() already called */
+                return MSG_PROCESS_ERROR;
+            }
+        }
+    }
+
+    return MSG_PROCESS_FINISHED_READING;
+}
+
+int tls_construct_change_cipher_spec(SSL *s, WPACKET *pkt)
+{
+    if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_TLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    return 1;
+}
+
+/* Add a certificate to the WPACKET */
+static int ssl_add_cert_to_wpacket(SSL *s, WPACKET *pkt, X509 *x, int chain)
+{
+    int len;
+    unsigned char *outbytes;
+
+    len = i2d_X509(x, NULL);
+    if (len < 0) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_ADD_CERT_TO_WPACKET,
+                 ERR_R_BUF_LIB);
+        return 0;
+    }
+    if (!WPACKET_sub_allocate_bytes_u24(pkt, len, &outbytes)
+            || i2d_X509(x, &outbytes) != len) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_ADD_CERT_TO_WPACKET,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    if (SSL_IS_TLS13(s)
+            && !tls_construct_extensions(s, pkt, SSL_EXT_TLS1_3_CERTIFICATE, x,
+                                         chain)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    return 1;
+}
+
+/* Add certificate chain to provided WPACKET */
+static int ssl_add_cert_chain(SSL *s, WPACKET *pkt, CERT_PKEY *cpk)
+{
+    int i, chain_count;
+    X509 *x;
+    STACK_OF(X509) *extra_certs;
+    STACK_OF(X509) *chain = NULL;
+    X509_STORE *chain_store;
+
+    if (cpk == NULL || cpk->x509 == NULL)
+        return 1;
+
+    x = cpk->x509;
+
+    /*
+     * If we have a certificate specific chain use it, else use parent ctx.
+     */
+    if (cpk->chain != NULL)
+        extra_certs = cpk->chain;
+    else
+        extra_certs = s->ctx->extra_certs;
+
+    if ((s->mode & SSL_MODE_NO_AUTO_CHAIN) || extra_certs)
+        chain_store = NULL;
+    else if (s->cert->chain_store)
+        chain_store = s->cert->chain_store;
+    else
+        chain_store = s->ctx->cert_store;
+
+    if (chain_store != NULL) {
+        X509_STORE_CTX *xs_ctx = X509_STORE_CTX_new();
+
+        if (xs_ctx == NULL) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_ADD_CERT_CHAIN,
+                     ERR_R_MALLOC_FAILURE);
+            return 0;
+        }
+        if (!X509_STORE_CTX_init(xs_ctx, chain_store, x, NULL)) {
+            X509_STORE_CTX_free(xs_ctx);
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_ADD_CERT_CHAIN,
+                     ERR_R_X509_LIB);
+            return 0;
+        }
+        /*
+         * It is valid for the chain not to be complete (because normally we
+         * don't include the root cert in the chain). Therefore we deliberately
+         * ignore the error return from this call. We're not actually verifying
+         * the cert - we're just building as much of the chain as we can
+         */
+        (void)X509_verify_cert(xs_ctx);
+        /* Don't leave errors in the queue */
+        ERR_clear_error();
+        chain = X509_STORE_CTX_get0_chain(xs_ctx);
+        i = ssl_security_cert_chain(s, chain, NULL, 0);
+        if (i != 1) {
+#if 0
+            /* Dummy error calls so mkerr generates them */
+            SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, SSL_R_EE_KEY_TOO_SMALL);
+            SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, SSL_R_CA_KEY_TOO_SMALL);
+            SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, SSL_R_CA_MD_TOO_WEAK);
+#endif
+            X509_STORE_CTX_free(xs_ctx);
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_ADD_CERT_CHAIN, i);
+            return 0;
+        }
+        chain_count = sk_X509_num(chain);
+        for (i = 0; i < chain_count; i++) {
+            x = sk_X509_value(chain, i);
+
+            if (!ssl_add_cert_to_wpacket(s, pkt, x, i)) {
+                /* SSLfatal() already called */
+                X509_STORE_CTX_free(xs_ctx);
+                return 0;
+            }
+        }
+        X509_STORE_CTX_free(xs_ctx);
+    } else {
+        i = ssl_security_cert_chain(s, extra_certs, x, 0);
+        if (i != 1) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_ADD_CERT_CHAIN, i);
+            return 0;
+        }
+        if (!ssl_add_cert_to_wpacket(s, pkt, x, 0)) {
+            /* SSLfatal() already called */
+            return 0;
+        }
+        for (i = 0; i < sk_X509_num(extra_certs); i++) {
+            x = sk_X509_value(extra_certs, i);
+            if (!ssl_add_cert_to_wpacket(s, pkt, x, i + 1)) {
+                /* SSLfatal() already called */
+                return 0;
+            }
+        }
+    }
+    return 1;
+}
+
+unsigned long ssl3_output_cert_chain(SSL *s, WPACKET *pkt, CERT_PKEY *cpk)
+{
+    if (!WPACKET_start_sub_packet_u24(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_OUTPUT_CERT_CHAIN,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    if (!ssl_add_cert_chain(s, pkt, cpk))
+        return 0;
+
+    if (!WPACKET_close(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_OUTPUT_CERT_CHAIN,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    return 1;
+}
+
+/*
+ * Tidy up after the end of a handshake. In the case of SCTP this may result
+ * in NBIO events. If |clearbufs| is set then init_buf and the wbio buffer is
+ * freed up as well.
+ */
+WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst, int clearbufs, int stop)
+{
+    void (*cb) (const SSL *ssl, int type, int val) = NULL;
+    int cleanuphand = s->statem.cleanuphand;
+
+    if (clearbufs) {
+        if (!SSL_IS_DTLS(s)
+#ifndef OPENSSL_NO_SCTP
+            /*
+             * RFC6083: SCTP provides a reliable and in-sequence transport service for DTLS
+             * messages that require it. Therefore, DTLS procedures for retransmissions
+             * MUST NOT be used.
+             * Hence the init_buf can be cleared when DTLS over SCTP as transport is used.
+             */
+            || BIO_dgram_is_sctp(SSL_get_wbio(s))
+#endif
+            ) {
+            /*
+             * We don't do this in DTLS over UDP because we may still need the init_buf
+             * in case there are any unexpected retransmits
+             */
+            BUF_MEM_free(s->init_buf);
+            s->init_buf = NULL;
+        }
+
+        if (!ssl_free_wbio_buffer(s)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_FINISH_HANDSHAKE,
+                     ERR_R_INTERNAL_ERROR);
+            return WORK_ERROR;
+        }
+        s->init_num = 0;
+    }
+
+    if (SSL_IS_TLS13(s) && !s->server
+            && s->post_handshake_auth == SSL_PHA_REQUESTED)
+        s->post_handshake_auth = SSL_PHA_EXT_SENT;
+
+    /*
+     * Only set if there was a Finished message and this isn't after a TLSv1.3
+     * post handshake exchange
+     */
+    if (cleanuphand) {
+        /* skipped if we just sent a HelloRequest */
+        s->renegotiate = 0;
+        s->new_session = 0;
+        s->statem.cleanuphand = 0;
+        s->ext.ticket_expected = 0;
+
+        ssl3_cleanup_key_block(s);
+
+        if (s->server) {
+            /*
+             * In TLSv1.3 we update the cache as part of constructing the
+             * NewSessionTicket
+             */
+            if (!SSL_IS_TLS13(s))
+                ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
+
+            /* N.B. s->ctx may not equal s->session_ctx */
+            tsan_counter(&s->ctx->stats.sess_accept_good);
+            s->handshake_func = ossl_statem_accept;
+        } else {
+            if (SSL_IS_TLS13(s)) {
+                /*
+                 * We encourage applications to only use TLSv1.3 tickets once,
+                 * so we remove this one from the cache.
+                 */
+                if ((s->session_ctx->session_cache_mode
+                     & SSL_SESS_CACHE_CLIENT) != 0)
+                    SSL_CTX_remove_session(s->session_ctx, s->session);
+            } else {
+                /*
+                 * In TLSv1.3 we update the cache as part of processing the
+                 * NewSessionTicket
+                 */
+                ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
+            }
+            if (s->hit)
+                tsan_counter(&s->session_ctx->stats.sess_hit);
+
+            s->handshake_func = ossl_statem_connect;
+            tsan_counter(&s->session_ctx->stats.sess_connect_good);
+        }
+
+        if (SSL_IS_DTLS(s)) {
+            /* done with handshaking */
+            s->d1->handshake_read_seq = 0;
+            s->d1->handshake_write_seq = 0;
+            s->d1->next_handshake_write_seq = 0;
+            dtls1_clear_received_buffer(s);
+        }
+    }
+
+    if (s->info_callback != NULL)
+        cb = s->info_callback;
+    else if (s->ctx->info_callback != NULL)
+        cb = s->ctx->info_callback;
+
+    /* The callback may expect us to not be in init at handshake done */
+    ossl_statem_set_in_init(s, 0);
+
+    if (cb != NULL) {
+        if (cleanuphand
+                || !SSL_IS_TLS13(s)
+                || SSL_IS_FIRST_HANDSHAKE(s))
+            cb(s, SSL_CB_HANDSHAKE_DONE, 1);
+    }
+
+    if (!stop) {
+        /* If we've got more work to do we go back into init */
+        ossl_statem_set_in_init(s, 1);
+        return WORK_FINISHED_CONTINUE;
+    }
+
+    return WORK_FINISHED_STOP;
+}
+
+int tls_get_message_header(SSL *s, int *mt)
+{
+    /* s->init_num < SSL3_HM_HEADER_LENGTH */
+    int skip_message, i, recvd_type;
+    unsigned char *p;
+    size_t l, readbytes;
+
+    p = (unsigned char *)s->init_buf->data;
+
+    do {
+        while (s->init_num < SSL3_HM_HEADER_LENGTH) {
+            i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
+                                          &p[s->init_num],
+                                          SSL3_HM_HEADER_LENGTH - s->init_num,
+                                          0, &readbytes);
+            if (i <= 0) {
+                s->rwstate = SSL_READING;
+                return 0;
+            }
+            if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
+                /*
+                 * A ChangeCipherSpec must be a single byte and may not occur
+                 * in the middle of a handshake message.
+                 */
+                if (s->init_num != 0 || readbytes != 1 || p[0] != SSL3_MT_CCS) {
+                    SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
+                             SSL_F_TLS_GET_MESSAGE_HEADER,
+                             SSL_R_BAD_CHANGE_CIPHER_SPEC);
+                    return 0;
+                }
+                if (s->statem.hand_state == TLS_ST_BEFORE
+                        && (s->s3->flags & TLS1_FLAGS_STATELESS) != 0) {
+                    /*
+                     * We are stateless and we received a CCS. Probably this is
+                     * from a client between the first and second ClientHellos.
+                     * We should ignore this, but return an error because we do
+                     * not return success until we see the second ClientHello
+                     * with a valid cookie.
+                     */
+                    return 0;
+                }
+                s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
+                s->init_num = readbytes - 1;
+                s->init_msg = s->init_buf->data;
+                s->s3->tmp.message_size = readbytes;
+                return 1;
+            } else if (recvd_type != SSL3_RT_HANDSHAKE) {
+                SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
+                         SSL_F_TLS_GET_MESSAGE_HEADER,
+                         SSL_R_CCS_RECEIVED_EARLY);
+                return 0;
+            }
+            s->init_num += readbytes;
+        }
+
+        skip_message = 0;
+        if (!s->server)
+            if (s->statem.hand_state != TLS_ST_OK
+                    && p[0] == SSL3_MT_HELLO_REQUEST)
+                /*
+                 * The server may always send 'Hello Request' messages --
+                 * we are doing a handshake anyway now, so ignore them if
+                 * their format is correct. Does not count for 'Finished'
+                 * MAC.
+                 */
+                if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
+                    s->init_num = 0;
+                    skip_message = 1;
+
+                    if (s->msg_callback)
+                        s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
+                                        p, SSL3_HM_HEADER_LENGTH, s,
+                                        s->msg_callback_arg);
+                }
+    } while (skip_message);
+    /* s->init_num == SSL3_HM_HEADER_LENGTH */
+
+    *mt = *p;
+    s->s3->tmp.message_type = *(p++);
+
+    if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
+        /*
+         * Only happens with SSLv3+ in an SSLv2 backward compatible
+         * ClientHello
+         *
+         * Total message size is the remaining record bytes to read
+         * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
+         */
+        l = RECORD_LAYER_get_rrec_length(&s->rlayer)
+            + SSL3_HM_HEADER_LENGTH;
+        s->s3->tmp.message_size = l;
+
+        s->init_msg = s->init_buf->data;
+        s->init_num = SSL3_HM_HEADER_LENGTH;
+    } else {
+        n2l3(p, l);
+        /* BUF_MEM_grow takes an 'int' parameter */
+        if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
+            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_GET_MESSAGE_HEADER,
+                     SSL_R_EXCESSIVE_MESSAGE_SIZE);
+            return 0;
+        }
+        s->s3->tmp.message_size = l;
+
+        s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
+        s->init_num = 0;
+    }
+
+    return 1;
+}
+
+int tls_get_message_body(SSL *s, size_t *len)
+{
+    size_t n, readbytes;
+    unsigned char *p;
+    int i;
+
+    if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
+        /* We've already read everything in */
+        *len = (unsigned long)s->init_num;
+        return 1;
+    }
+
+    p = s->init_msg;
+    n = s->s3->tmp.message_size - s->init_num;
+    while (n > 0) {
+        i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
+                                      &p[s->init_num], n, 0, &readbytes);
+        if (i <= 0) {
+            s->rwstate = SSL_READING;
+            *len = 0;
+            return 0;
+        }
+        s->init_num += readbytes;
+        n -= readbytes;
+    }
+
+    /*
+     * If receiving Finished, record MAC of prior handshake messages for
+     * Finished verification.
+     */
+    if (*(s->init_buf->data) == SSL3_MT_FINISHED && !ssl3_take_mac(s)) {
+        /* SSLfatal() already called */
+        *len = 0;
+        return 0;
+    }
+
+    /* Feed this message into MAC computation. */
+    if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
+        if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
+                             s->init_num)) {
+            /* SSLfatal() already called */
+            *len = 0;
+            return 0;
+        }
+        if (s->msg_callback)
+            s->msg_callback(0, SSL2_VERSION, 0, s->init_buf->data,
+                            (size_t)s->init_num, s, s->msg_callback_arg);
+    } else {
+        /*
+         * We defer feeding in the HRR until later. We'll do it as part of
+         * processing the message
+         * The TLsv1.3 handshake transcript stops at the ClientFinished
+         * message.
+         */
+#define SERVER_HELLO_RANDOM_OFFSET  (SSL3_HM_HEADER_LENGTH + 2)
+        /* KeyUpdate and NewSessionTicket do not need to be added */
+        if (!SSL_IS_TLS13(s) || (s->s3->tmp.message_type != SSL3_MT_NEWSESSION_TICKET
+                                 && s->s3->tmp.message_type != SSL3_MT_KEY_UPDATE)) {
+            if (s->s3->tmp.message_type != SSL3_MT_SERVER_HELLO
+                    || s->init_num < SERVER_HELLO_RANDOM_OFFSET + SSL3_RANDOM_SIZE
+                    || memcmp(hrrrandom,
+                              s->init_buf->data + SERVER_HELLO_RANDOM_OFFSET,
+                              SSL3_RANDOM_SIZE) != 0) {
+                if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
+                                     s->init_num + SSL3_HM_HEADER_LENGTH)) {
+                    /* SSLfatal() already called */
+                    *len = 0;
+                    return 0;
+                }
+            }
+        }
+        if (s->msg_callback)
+            s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
+                            (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
+                            s->msg_callback_arg);
+    }
+
+    *len = s->init_num;
+    return 1;
+}
+
+static const X509ERR2ALERT x509table[] = {
+    {X509_V_ERR_APPLICATION_VERIFICATION, SSL_AD_HANDSHAKE_FAILURE},
+    {X509_V_ERR_CA_KEY_TOO_SMALL, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_EC_KEY_EXPLICIT_PARAMS, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_CA_MD_TOO_WEAK, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_CERT_CHAIN_TOO_LONG, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_CERT_HAS_EXPIRED, SSL_AD_CERTIFICATE_EXPIRED},
+    {X509_V_ERR_CERT_NOT_YET_VALID, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_CERT_REJECTED, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_CERT_REVOKED, SSL_AD_CERTIFICATE_REVOKED},
+    {X509_V_ERR_CERT_SIGNATURE_FAILURE, SSL_AD_DECRYPT_ERROR},
+    {X509_V_ERR_CERT_UNTRUSTED, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_CRL_HAS_EXPIRED, SSL_AD_CERTIFICATE_EXPIRED},
+    {X509_V_ERR_CRL_NOT_YET_VALID, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_CRL_SIGNATURE_FAILURE, SSL_AD_DECRYPT_ERROR},
+    {X509_V_ERR_DANE_NO_MATCH, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_EE_KEY_TOO_SMALL, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_EMAIL_MISMATCH, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_HOSTNAME_MISMATCH, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_INVALID_CA, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_INVALID_CALL, SSL_AD_INTERNAL_ERROR},
+    {X509_V_ERR_INVALID_PURPOSE, SSL_AD_UNSUPPORTED_CERTIFICATE},
+    {X509_V_ERR_IP_ADDRESS_MISMATCH, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_OUT_OF_MEM, SSL_AD_INTERNAL_ERROR},
+    {X509_V_ERR_PATH_LENGTH_EXCEEDED, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_STORE_LOOKUP, SSL_AD_INTERNAL_ERROR},
+    {X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE, SSL_AD_BAD_CERTIFICATE},
+    {X509_V_ERR_UNABLE_TO_GET_CRL, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE, SSL_AD_UNKNOWN_CA},
+    {X509_V_ERR_UNSPECIFIED, SSL_AD_INTERNAL_ERROR},
+
+    /* Last entry; return this if we don't find the value above. */
+    {X509_V_OK, SSL_AD_CERTIFICATE_UNKNOWN}
+};
+
+int ssl_x509err2alert(int x509err)
+{
+    const X509ERR2ALERT *tp;
+
+    for (tp = x509table; tp->x509err != X509_V_OK; ++tp)
+        if (tp->x509err == x509err)
+            break;
+    return tp->alert;
+}
+
+int ssl_allow_compression(SSL *s)
+{
+    if (s->options & SSL_OP_NO_COMPRESSION)
+        return 0;
+    return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);
+}
+
+static int version_cmp(const SSL *s, int a, int b)
+{
+    int dtls = SSL_IS_DTLS(s);
+
+    if (a == b)
+        return 0;
+    if (!dtls)
+        return a < b ? -1 : 1;
+    return DTLS_VERSION_LT(a, b) ? -1 : 1;
+}
+
+typedef struct {
+    int version;
+    const SSL_METHOD *(*cmeth) (void);
+    const SSL_METHOD *(*smeth) (void);
+} version_info;
+
+#if TLS_MAX_VERSION != TLS1_3_VERSION
+# error Code needs update for TLS_method() support beyond TLS1_3_VERSION.
+#endif
+
+/* Must be in order high to low */
+static const version_info tls_version_table[] = {
+#ifndef OPENSSL_NO_TLS1_3
+    {TLS1_3_VERSION, tlsv1_3_client_method, tlsv1_3_server_method},
+#else
+    {TLS1_3_VERSION, NULL, NULL},
+#endif
+#ifndef OPENSSL_NO_TLS1_2
+    {TLS1_2_VERSION, tlsv1_2_client_method, tlsv1_2_server_method},
+#else
+    {TLS1_2_VERSION, NULL, NULL},
+#endif
+#ifndef OPENSSL_NO_TLS1_1
+    {TLS1_1_VERSION, tlsv1_1_client_method, tlsv1_1_server_method},
+#else
+    {TLS1_1_VERSION, NULL, NULL},
+#endif
+#ifndef OPENSSL_NO_TLS1
+    {TLS1_VERSION, tlsv1_client_method, tlsv1_server_method},
+#else
+    {TLS1_VERSION, NULL, NULL},
+#endif
+#ifndef OPENSSL_NO_SSL3
+    {SSL3_VERSION, sslv3_client_method, sslv3_server_method},
+#else
+    {SSL3_VERSION, NULL, NULL},
+#endif
+    {0, NULL, NULL},
+};
+
+#if DTLS_MAX_VERSION != DTLS1_2_VERSION
+# error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
+#endif
+
+/* Must be in order high to low */
+static const version_info dtls_version_table[] = {
+#ifndef OPENSSL_NO_DTLS1_2
+    {DTLS1_2_VERSION, dtlsv1_2_client_method, dtlsv1_2_server_method},
+#else
+    {DTLS1_2_VERSION, NULL, NULL},
+#endif
+#ifndef OPENSSL_NO_DTLS1
+    {DTLS1_VERSION, dtlsv1_client_method, dtlsv1_server_method},
+    {DTLS1_BAD_VER, dtls_bad_ver_client_method, NULL},
+#else
+    {DTLS1_VERSION, NULL, NULL},
+    {DTLS1_BAD_VER, NULL, NULL},
+#endif
+    {0, NULL, NULL},
+};
+
+/*
+ * ssl_method_error - Check whether an SSL_METHOD is enabled.
+ *
+ * @s: The SSL handle for the candidate method
+ * @method: the intended method.
+ *
+ * Returns 0 on success, or an SSL error reason on failure.
+ */
+static int ssl_method_error(const SSL *s, const SSL_METHOD *method)
+{
+    int version = method->version;
+
+    if ((s->min_proto_version != 0 &&
+         version_cmp(s, version, s->min_proto_version) < 0) ||
+        ssl_security(s, SSL_SECOP_VERSION, 0, version, NULL) == 0)
+        return SSL_R_VERSION_TOO_LOW;
+
+    if (s->max_proto_version != 0 &&
+        version_cmp(s, version, s->max_proto_version) > 0)
+        return SSL_R_VERSION_TOO_HIGH;
+
+    if ((s->options & method->mask) != 0)
+        return SSL_R_UNSUPPORTED_PROTOCOL;
+    if ((method->flags & SSL_METHOD_NO_SUITEB) != 0 && tls1_suiteb(s))
+        return SSL_R_AT_LEAST_TLS_1_2_NEEDED_IN_SUITEB_MODE;
+
+    return 0;
+}
+
+/*
+ * Only called by servers. Returns 1 if the server has a TLSv1.3 capable
+ * certificate type, or has PSK or a certificate callback configured, or has
+ * a servername callback configured. Otherwise returns 0.
+ */
+static int is_tls13_capable(const SSL *s)
+{
+    int i;
+#ifndef OPENSSL_NO_EC
+    int curve;
+    EC_KEY *eckey;
+#endif
+
+    if (!ossl_assert(s->ctx != NULL) || !ossl_assert(s->session_ctx != NULL))
+        return 0;
+
+    /*
+     * A servername callback can change the available certs, so if a servername
+     * cb is set then we just assume TLSv1.3 will be ok
+     */
+    if (s->ctx->ext.servername_cb != NULL
+            || s->session_ctx->ext.servername_cb != NULL)
+        return 1;
+
+#ifndef OPENSSL_NO_PSK
+    if (s->psk_server_callback != NULL)
+        return 1;
+#endif
+
+    if (s->psk_find_session_cb != NULL || s->cert->cert_cb != NULL)
+        return 1;
+
+    for (i = 0; i < SSL_PKEY_NUM; i++) {
+        /* Skip over certs disallowed for TLSv1.3 */
+        switch (i) {
+        case SSL_PKEY_DSA_SIGN:
+        case SSL_PKEY_GOST01:
+        case SSL_PKEY_GOST12_256:
+        case SSL_PKEY_GOST12_512:
+            continue;
+        default:
+            break;
+        }
+        if (!ssl_has_cert(s, i))
+            continue;
+#ifndef OPENSSL_NO_EC
+        if (i != SSL_PKEY_ECC)
+            return 1;
+        /*
+         * Prior to TLSv1.3 sig algs allowed any curve to be used. TLSv1.3 is
+         * more restrictive so check that our sig algs are consistent with this
+         * EC cert. See section 4.2.3 of RFC8446.
+         */
+        eckey = EVP_PKEY_get0_EC_KEY(s->cert->pkeys[SSL_PKEY_ECC].privatekey);
+        if (eckey == NULL)
+            continue;
+        curve = EC_GROUP_get_curve_name(EC_KEY_get0_group(eckey));
+        if (tls_check_sigalg_curve(s, curve))
+            return 1;
+#else
+        return 1;
+#endif
+    }
+
+    return 0;
+}
+
+/*
+ * ssl_version_supported - Check that the specified `version` is supported by
+ * `SSL *` instance
+ *
+ * @s: The SSL handle for the candidate method
+ * @version: Protocol version to test against
+ *
+ * Returns 1 when supported, otherwise 0
+ */
+int ssl_version_supported(const SSL *s, int version, const SSL_METHOD **meth)
+{
+    const version_info *vent;
+    const version_info *table;
+
+    switch (s->method->version) {
+    default:
+        /* Version should match method version for non-ANY method */
+        return version_cmp(s, version, s->version) == 0;
+    case TLS_ANY_VERSION:
+        table = tls_version_table;
+        break;
+    case DTLS_ANY_VERSION:
+        table = dtls_version_table;
+        break;
+    }
+
+    for (vent = table;
+         vent->version != 0 && version_cmp(s, version, vent->version) <= 0;
+         ++vent) {
+        if (vent->cmeth != NULL
+                && version_cmp(s, version, vent->version) == 0
+                && ssl_method_error(s, vent->cmeth()) == 0
+                && (!s->server
+                    || version != TLS1_3_VERSION
+                    || is_tls13_capable(s))) {
+            if (meth != NULL)
+                *meth = vent->cmeth();
+            return 1;
+        }
+    }
+    return 0;
+}
+
+/*
+ * ssl_check_version_downgrade - In response to RFC7507 SCSV version
+ * fallback indication from a client check whether we're using the highest
+ * supported protocol version.
+ *
+ * @s server SSL handle.
+ *
+ * Returns 1 when using the highest enabled version, 0 otherwise.
+ */
+int ssl_check_version_downgrade(SSL *s)
+{
+    const version_info *vent;
+    const version_info *table;
+
+    /*
+     * Check that the current protocol is the highest enabled version
+     * (according to s->ctx->method, as version negotiation may have changed
+     * s->method).
+     */
+    if (s->version == s->ctx->method->version)
+        return 1;
+
+    /*
+     * Apparently we're using a version-flexible SSL_METHOD (not at its
+     * highest protocol version).
+     */
+    if (s->ctx->method->version == TLS_method()->version)
+        table = tls_version_table;
+    else if (s->ctx->method->version == DTLS_method()->version)
+        table = dtls_version_table;
+    else {
+        /* Unexpected state; fail closed. */
+        return 0;
+    }
+
+    for (vent = table; vent->version != 0; ++vent) {
+        if (vent->smeth != NULL && ssl_method_error(s, vent->smeth()) == 0)
+            return s->version == vent->version;
+    }
+    return 0;
+}
+
+/*
+ * ssl_set_version_bound - set an upper or lower bound on the supported (D)TLS
+ * protocols, provided the initial (D)TLS method is version-flexible.  This
+ * function sanity-checks the proposed value and makes sure the method is
+ * version-flexible, then sets the limit if all is well.
+ *
+ * @method_version: The version of the current SSL_METHOD.
+ * @version: the intended limit.
+ * @bound: pointer to limit to be updated.
+ *
+ * Returns 1 on success, 0 on failure.
+ */
+int ssl_set_version_bound(int method_version, int version, int *bound)
+{
+    int valid_tls;
+    int valid_dtls;
+
+    if (version == 0) {
+        *bound = version;
+        return 1;
+    }
+
+    valid_tls = version >= SSL3_VERSION && version <= TLS_MAX_VERSION;
+    valid_dtls =
+        DTLS_VERSION_LE(version, DTLS_MAX_VERSION) &&
+        DTLS_VERSION_GE(version, DTLS1_BAD_VER);
+
+    if (!valid_tls && !valid_dtls)
+        return 0;
+
+    /*-
+     * Restrict TLS methods to TLS protocol versions.
+     * Restrict DTLS methods to DTLS protocol versions.
+     * Note, DTLS version numbers are decreasing, use comparison macros.
+     *
+     * Note that for both lower-bounds we use explicit versions, not
+     * (D)TLS_MIN_VERSION.  This is because we don't want to break user
+     * configurations.  If the MIN (supported) version ever rises, the user's
+     * "floor" remains valid even if no longer available.  We don't expect the
+     * MAX ceiling to ever get lower, so making that variable makes sense.
+     *
+     * We ignore attempts to set bounds on version-inflexible methods,
+     * returning success.
+     */
+    switch (method_version) {
+    default:
+        break;
+
+    case TLS_ANY_VERSION:
+        if (valid_tls)
+            *bound = version;
+        break;
+
+    case DTLS_ANY_VERSION:
+        if (valid_dtls)
+            *bound = version;
+        break;
+    }
+    return 1;
+}
+
+static void check_for_downgrade(SSL *s, int vers, DOWNGRADE *dgrd)
+{
+    if (vers == TLS1_2_VERSION
+            && ssl_version_supported(s, TLS1_3_VERSION, NULL)) {
+        *dgrd = DOWNGRADE_TO_1_2;
+    } else if (!SSL_IS_DTLS(s)
+            && vers < TLS1_2_VERSION
+               /*
+                * We need to ensure that a server that disables TLSv1.2
+                * (creating a hole between TLSv1.3 and TLSv1.1) can still
+                * complete handshakes with clients that support TLSv1.2 and
+                * below. Therefore we do not enable the sentinel if TLSv1.3 is
+                * enabled and TLSv1.2 is not.
+                */
+            && ssl_version_supported(s, TLS1_2_VERSION, NULL)) {
+        *dgrd = DOWNGRADE_TO_1_1;
+    } else {
+        *dgrd = DOWNGRADE_NONE;
+    }
+}
+
+/*
+ * ssl_choose_server_version - Choose server (D)TLS version.  Called when the
+ * client HELLO is received to select the final server protocol version and
+ * the version specific method.
+ *
+ * @s: server SSL handle.
+ *
+ * Returns 0 on success or an SSL error reason number on failure.
+ */
+int ssl_choose_server_version(SSL *s, CLIENTHELLO_MSG *hello, DOWNGRADE *dgrd)
+{
+    /*-
+     * With version-flexible methods we have an initial state with:
+     *
+     *   s->method->version == (D)TLS_ANY_VERSION,
+     *   s->version == (D)TLS_MAX_VERSION.
+     *
+     * So we detect version-flexible methods via the method version, not the
+     * handle version.
+     */
+    int server_version = s->method->version;
+    int client_version = hello->legacy_version;
+    const version_info *vent;
+    const version_info *table;
+    int disabled = 0;
+    RAW_EXTENSION *suppversions;
+
+    s->client_version = client_version;
+
+    switch (server_version) {
+    default:
+        if (!SSL_IS_TLS13(s)) {
+            if (version_cmp(s, client_version, s->version) < 0)
+                return SSL_R_WRONG_SSL_VERSION;
+            *dgrd = DOWNGRADE_NONE;
+            /*
+             * If this SSL handle is not from a version flexible method we don't
+             * (and never did) check min/max FIPS or Suite B constraints.  Hope
+             * that's OK.  It is up to the caller to not choose fixed protocol
+             * versions they don't want.  If not, then easy to fix, just return
+             * ssl_method_error(s, s->method)
+             */
+            return 0;
+        }
+        /*
+         * Fall through if we are TLSv1.3 already (this means we must be after
+         * a HelloRetryRequest
+         */
+        /* fall thru */
+    case TLS_ANY_VERSION:
+        table = tls_version_table;
+        break;
+    case DTLS_ANY_VERSION:
+        table = dtls_version_table;
+        break;
+    }
+
+    suppversions = &hello->pre_proc_exts[TLSEXT_IDX_supported_versions];
+
+    /* If we did an HRR then supported versions is mandatory */
+    if (!suppversions->present && s->hello_retry_request != SSL_HRR_NONE)
+        return SSL_R_UNSUPPORTED_PROTOCOL;
+
+    if (suppversions->present && !SSL_IS_DTLS(s)) {
+        unsigned int candidate_vers = 0;
+        unsigned int best_vers = 0;
+        const SSL_METHOD *best_method = NULL;
+        PACKET versionslist;
+
+        suppversions->parsed = 1;
+
+        if (!PACKET_as_length_prefixed_1(&suppversions->data, &versionslist)) {
+            /* Trailing or invalid data? */
+            return SSL_R_LENGTH_MISMATCH;
+        }
+
+        /*
+         * The TLSv1.3 spec says the client MUST set this to TLS1_2_VERSION.
+         * The spec only requires servers to check that it isn't SSLv3:
+         * "Any endpoint receiving a Hello message with
+         * ClientHello.legacy_version or ServerHello.legacy_version set to
+         * 0x0300 MUST abort the handshake with a "protocol_version" alert."
+         * We are slightly stricter and require that it isn't SSLv3 or lower.
+         * We tolerate TLSv1 and TLSv1.1.
+         */
+        if (client_version <= SSL3_VERSION)
+            return SSL_R_BAD_LEGACY_VERSION;
+
+        while (PACKET_get_net_2(&versionslist, &candidate_vers)) {
+            if (version_cmp(s, candidate_vers, best_vers) <= 0)
+                continue;
+            if (ssl_version_supported(s, candidate_vers, &best_method))
+                best_vers = candidate_vers;
+        }
+        if (PACKET_remaining(&versionslist) != 0) {
+            /* Trailing data? */
+            return SSL_R_LENGTH_MISMATCH;
+        }
+
+        if (best_vers > 0) {
+            if (s->hello_retry_request != SSL_HRR_NONE) {
+                /*
+                 * This is after a HelloRetryRequest so we better check that we
+                 * negotiated TLSv1.3
+                 */
+                if (best_vers != TLS1_3_VERSION)
+                    return SSL_R_UNSUPPORTED_PROTOCOL;
+                return 0;
+            }
+            check_for_downgrade(s, best_vers, dgrd);
+            s->version = best_vers;
+            s->method = best_method;
+            return 0;
+        }
+        return SSL_R_UNSUPPORTED_PROTOCOL;
+    }
+
+    /*
+     * If the supported versions extension isn't present, then the highest
+     * version we can negotiate is TLSv1.2
+     */
+    if (version_cmp(s, client_version, TLS1_3_VERSION) >= 0)
+        client_version = TLS1_2_VERSION;
+
+    /*
+     * No supported versions extension, so we just use the version supplied in
+     * the ClientHello.
+     */
+    for (vent = table; vent->version != 0; ++vent) {
+        const SSL_METHOD *method;
+
+        if (vent->smeth == NULL ||
+            version_cmp(s, client_version, vent->version) < 0)
+            continue;
+        method = vent->smeth();
+        if (ssl_method_error(s, method) == 0) {
+            check_for_downgrade(s, vent->version, dgrd);
+            s->version = vent->version;
+            s->method = method;
+            return 0;
+        }
+        disabled = 1;
+    }
+    return disabled ? SSL_R_UNSUPPORTED_PROTOCOL : SSL_R_VERSION_TOO_LOW;
+}
+
+/*
+ * ssl_choose_client_version - Choose client (D)TLS version.  Called when the
+ * server HELLO is received to select the final client protocol version and
+ * the version specific method.
+ *
+ * @s: client SSL handle.
+ * @version: The proposed version from the server's HELLO.
+ * @extensions: The extensions received
+ *
+ * Returns 1 on success or 0 on error.
+ */
+int ssl_choose_client_version(SSL *s, int version, RAW_EXTENSION *extensions)
+{
+    const version_info *vent;
+    const version_info *table;
+    int ret, ver_min, ver_max, real_max, origv;
+
+    origv = s->version;
+    s->version = version;
+
+    /* This will overwrite s->version if the extension is present */
+    if (!tls_parse_extension(s, TLSEXT_IDX_supported_versions,
+                             SSL_EXT_TLS1_2_SERVER_HELLO
+                             | SSL_EXT_TLS1_3_SERVER_HELLO, extensions,
+                             NULL, 0)) {
+        s->version = origv;
+        return 0;
+    }
+
+    if (s->hello_retry_request != SSL_HRR_NONE
+            && s->version != TLS1_3_VERSION) {
+        s->version = origv;
+        SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_SSL_CHOOSE_CLIENT_VERSION,
+                 SSL_R_WRONG_SSL_VERSION);
+        return 0;
+    }
+
+    switch (s->method->version) {
+    default:
+        if (s->version != s->method->version) {
+            s->version = origv;
+            SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
+                     SSL_F_SSL_CHOOSE_CLIENT_VERSION,
+                     SSL_R_WRONG_SSL_VERSION);
+            return 0;
+        }
+        /*
+         * If this SSL handle is not from a version flexible method we don't
+         * (and never did) check min/max, FIPS or Suite B constraints.  Hope
+         * that's OK.  It is up to the caller to not choose fixed protocol
+         * versions they don't want.  If not, then easy to fix, just return
+         * ssl_method_error(s, s->method)
+         */
+        return 1;
+    case TLS_ANY_VERSION:
+        table = tls_version_table;
+        break;
+    case DTLS_ANY_VERSION:
+        table = dtls_version_table;
+        break;
+    }
+
+    ret = ssl_get_min_max_version(s, &ver_min, &ver_max, &real_max);
+    if (ret != 0) {
+        s->version = origv;
+        SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
+                 SSL_F_SSL_CHOOSE_CLIENT_VERSION, ret);
+        return 0;
+    }
+    if (SSL_IS_DTLS(s) ? DTLS_VERSION_LT(s->version, ver_min)
+                       : s->version < ver_min) {
+        s->version = origv;
+        SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
+                 SSL_F_SSL_CHOOSE_CLIENT_VERSION, SSL_R_UNSUPPORTED_PROTOCOL);
+        return 0;
+    } else if (SSL_IS_DTLS(s) ? DTLS_VERSION_GT(s->version, ver_max)
+                              : s->version > ver_max) {
+        s->version = origv;
+        SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
+                 SSL_F_SSL_CHOOSE_CLIENT_VERSION, SSL_R_UNSUPPORTED_PROTOCOL);
+        return 0;
+    }
+
+    if ((s->mode & SSL_MODE_SEND_FALLBACK_SCSV) == 0)
+        real_max = ver_max;
+
+    /* Check for downgrades */
+    if (s->version == TLS1_2_VERSION && real_max > s->version) {
+        if (memcmp(tls12downgrade,
+                   s->s3->server_random + SSL3_RANDOM_SIZE
+                                        - sizeof(tls12downgrade),
+                   sizeof(tls12downgrade)) == 0) {
+            s->version = origv;
+            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+                     SSL_F_SSL_CHOOSE_CLIENT_VERSION,
+                     SSL_R_INAPPROPRIATE_FALLBACK);
+            return 0;
+        }
+    } else if (!SSL_IS_DTLS(s)
+               && s->version < TLS1_2_VERSION
+               && real_max > s->version) {
+        if (memcmp(tls11downgrade,
+                   s->s3->server_random + SSL3_RANDOM_SIZE
+                                        - sizeof(tls11downgrade),
+                   sizeof(tls11downgrade)) == 0) {
+            s->version = origv;
+            SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
+                     SSL_F_SSL_CHOOSE_CLIENT_VERSION,
+                     SSL_R_INAPPROPRIATE_FALLBACK);
+            return 0;
+        }
+    }
+
+    for (vent = table; vent->version != 0; ++vent) {
+        if (vent->cmeth == NULL || s->version != vent->version)
+            continue;
+
+        s->method = vent->cmeth();
+        return 1;
+    }
+
+    s->version = origv;
+    SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_SSL_CHOOSE_CLIENT_VERSION,
+             SSL_R_UNSUPPORTED_PROTOCOL);
+    return 0;
+}
+
+/*
+ * ssl_get_min_max_version - get minimum and maximum protocol version
+ * @s: The SSL connection
+ * @min_version: The minimum supported version
+ * @max_version: The maximum supported version
+ * @real_max:    The highest version below the lowest compile time version hole
+ *               where that hole lies above at least one run-time enabled
+ *               protocol.
+ *
+ * Work out what version we should be using for the initial ClientHello if the
+ * version is initially (D)TLS_ANY_VERSION.  We apply any explicit SSL_OP_NO_xxx
+ * options, the MinProtocol and MaxProtocol configuration commands, any Suite B
+ * constraints and any floor imposed by the security level here,
+ * so we don't advertise the wrong protocol version to only reject the outcome later.
+ *
+ * Computing the right floor matters.  If, e.g., TLS 1.0 and 1.2 are enabled,
+ * TLS 1.1 is disabled, but the security level, Suite-B  and/or MinProtocol
+ * only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1.
+ *
+ * Returns 0 on success or an SSL error reason number on failure.  On failure
+ * min_version and max_version will also be set to 0.
+ */
+int ssl_get_min_max_version(const SSL *s, int *min_version, int *max_version,
+                            int *real_max)
+{
+    int version, tmp_real_max;
+    int hole;
+    const SSL_METHOD *single = NULL;
+    const SSL_METHOD *method;
+    const version_info *table;
+    const version_info *vent;
+
+    switch (s->method->version) {
+    default:
+        /*
+         * If this SSL handle is not from a version flexible method we don't
+         * (and never did) check min/max FIPS or Suite B constraints.  Hope
+         * that's OK.  It is up to the caller to not choose fixed protocol
+         * versions they don't want.  If not, then easy to fix, just return
+         * ssl_method_error(s, s->method)
+         */
+        *min_version = *max_version = s->version;
+        /*
+         * Providing a real_max only makes sense where we're using a version
+         * flexible method.
+         */
+        if (!ossl_assert(real_max == NULL))
+            return ERR_R_INTERNAL_ERROR;
+        return 0;
+    case TLS_ANY_VERSION:
+        table = tls_version_table;
+        break;
+    case DTLS_ANY_VERSION:
+        table = dtls_version_table;
+        break;
+    }
+
+    /*
+     * SSL_OP_NO_X disables all protocols above X *if* there are some protocols
+     * below X enabled. This is required in order to maintain the "version
+     * capability" vector contiguous. Any versions with a NULL client method
+     * (protocol version client is disabled at compile-time) is also a "hole".
+     *
+     * Our initial state is hole == 1, version == 0.  That is, versions above
+     * the first version in the method table are disabled (a "hole" above
+     * the valid protocol entries) and we don't have a selected version yet.
+     *
+     * Whenever "hole == 1", and we hit an enabled method, its version becomes
+     * the selected version, and the method becomes a candidate "single"
+     * method.  We're no longer in a hole, so "hole" becomes 0.
+     *
+     * If "hole == 0" and we hit an enabled method, then "single" is cleared,
+     * as we support a contiguous range of at least two methods.  If we hit
+     * a disabled method, then hole becomes true again, but nothing else
+     * changes yet, because all the remaining methods may be disabled too.
+     * If we again hit an enabled method after the new hole, it becomes
+     * selected, as we start from scratch.
+     */
+    *min_version = version = 0;
+    hole = 1;
+    if (real_max != NULL)
+        *real_max = 0;
+    tmp_real_max = 0;
+    for (vent = table; vent->version != 0; ++vent) {
+        /*
+         * A table entry with a NULL client method is still a hole in the
+         * "version capability" vector.
+         */
+        if (vent->cmeth == NULL) {
+            hole = 1;
+            tmp_real_max = 0;
+            continue;
+        }
+        method = vent->cmeth();
+
+        if (hole == 1 && tmp_real_max == 0)
+            tmp_real_max = vent->version;
+
+        if (ssl_method_error(s, method) != 0) {
+            hole = 1;
+        } else if (!hole) {
+            single = NULL;
+            *min_version = method->version;
+        } else {
+            if (real_max != NULL && tmp_real_max != 0)
+                *real_max = tmp_real_max;
+            version = (single = method)->version;
+            *min_version = version;
+            hole = 0;
+        }
+    }
+
+    *max_version = version;
+
+    /* Fail if everything is disabled */
+    if (version == 0)
+        return SSL_R_NO_PROTOCOLS_AVAILABLE;
+
+    return 0;
+}
+
+/*
+ * ssl_set_client_hello_version - Work out what version we should be using for
+ * the initial ClientHello.legacy_version field.
+ *
+ * @s: client SSL handle.
+ *
+ * Returns 0 on success or an SSL error reason number on failure.
+ */
+int ssl_set_client_hello_version(SSL *s)
+{
+    int ver_min, ver_max, ret;
+
+    /*
+     * In a renegotiation we always send the same client_version that we sent
+     * last time, regardless of which version we eventually negotiated.
+     */
+    if (!SSL_IS_FIRST_HANDSHAKE(s))
+        return 0;
+
+    ret = ssl_get_min_max_version(s, &ver_min, &ver_max, NULL);
+
+    if (ret != 0)
+        return ret;
+
+    s->version = ver_max;
+
+    /* TLS1.3 always uses TLS1.2 in the legacy_version field */
+    if (!SSL_IS_DTLS(s) && ver_max > TLS1_2_VERSION)
+        ver_max = TLS1_2_VERSION;
+
+    s->client_version = ver_max;
+    return 0;
+}
+
+/*
+ * Checks a list of |groups| to determine if the |group_id| is in it. If it is
+ * and |checkallow| is 1 then additionally check if the group is allowed to be
+ * used. Returns 1 if the group is in the list (and allowed if |checkallow| is
+ * 1) or 0 otherwise.
+ */
+#ifndef OPENSSL_NO_EC
+int check_in_list(SSL *s, uint16_t group_id, const uint16_t *groups,
+                  size_t num_groups, int checkallow)
+{
+    size_t i;
+
+    if (groups == NULL || num_groups == 0)
+        return 0;
+
+    for (i = 0; i < num_groups; i++) {
+        uint16_t group = groups[i];
+
+        if (group_id == group
+                && (!checkallow
+                    || tls_curve_allowed(s, group, SSL_SECOP_CURVE_CHECK))) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+#endif
+
+/* Replace ClientHello1 in the transcript hash with a synthetic message */
+int create_synthetic_message_hash(SSL *s, const unsigned char *hashval,
+                                  size_t hashlen, const unsigned char *hrr,
+                                  size_t hrrlen)
+{
+    unsigned char hashvaltmp[EVP_MAX_MD_SIZE];
+    unsigned char msghdr[SSL3_HM_HEADER_LENGTH];
+
+    memset(msghdr, 0, sizeof(msghdr));
+
+    if (hashval == NULL) {
+        hashval = hashvaltmp;
+        hashlen = 0;
+        /* Get the hash of the initial ClientHello */
+        if (!ssl3_digest_cached_records(s, 0)
+                || !ssl_handshake_hash(s, hashvaltmp, sizeof(hashvaltmp),
+                                       &hashlen)) {
+            /* SSLfatal() already called */
+            return 0;
+        }
+    }
+
+    /* Reinitialise the transcript hash */
+    if (!ssl3_init_finished_mac(s)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    /* Inject the synthetic message_hash message */
+    msghdr[0] = SSL3_MT_MESSAGE_HASH;
+    msghdr[SSL3_HM_HEADER_LENGTH - 1] = (unsigned char)hashlen;
+    if (!ssl3_finish_mac(s, msghdr, SSL3_HM_HEADER_LENGTH)
+            || !ssl3_finish_mac(s, hashval, hashlen)) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    /*
+     * Now re-inject the HRR and current message if appropriate (we just deleted
+     * it when we reinitialised the transcript hash above). Only necessary after
+     * receiving a ClientHello2 with a cookie.
+     */
+    if (hrr != NULL
+            && (!ssl3_finish_mac(s, hrr, hrrlen)
+                || !ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
+                                    s->s3->tmp.message_size
+                                    + SSL3_HM_HEADER_LENGTH))) {
+        /* SSLfatal() already called */
+        return 0;
+    }
+
+    return 1;
+}
+
+static int ca_dn_cmp(const X509_NAME *const *a, const X509_NAME *const *b)
+{
+    return X509_NAME_cmp(*a, *b);
+}
+
+int parse_ca_names(SSL *s, PACKET *pkt)
+{
+    STACK_OF(X509_NAME) *ca_sk = sk_X509_NAME_new(ca_dn_cmp);
+    X509_NAME *xn = NULL;
+    PACKET cadns;
+
+    if (ca_sk == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_PARSE_CA_NAMES,
+                 ERR_R_MALLOC_FAILURE);
+        goto err;
+    }
+    /* get the CA RDNs */
+    if (!PACKET_get_length_prefixed_2(pkt, &cadns)) {
+        SSLfatal(s, SSL_AD_DECODE_ERROR,SSL_F_PARSE_CA_NAMES,
+                 SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
+
+    while (PACKET_remaining(&cadns)) {
+        const unsigned char *namestart, *namebytes;
+        unsigned int name_len;
+
+        if (!PACKET_get_net_2(&cadns, &name_len)
+            || !PACKET_get_bytes(&cadns, &namebytes, name_len)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_PARSE_CA_NAMES,
+                     SSL_R_LENGTH_MISMATCH);
+            goto err;
+        }
+
+        namestart = namebytes;
+        if ((xn = d2i_X509_NAME(NULL, &namebytes, name_len)) == NULL) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_PARSE_CA_NAMES,
+                     ERR_R_ASN1_LIB);
+            goto err;
+        }
+        if (namebytes != (namestart + name_len)) {
+            SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_PARSE_CA_NAMES,
+                     SSL_R_CA_DN_LENGTH_MISMATCH);
+            goto err;
+        }
+
+        if (!sk_X509_NAME_push(ca_sk, xn)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_PARSE_CA_NAMES,
+                     ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+        xn = NULL;
+    }
+
+    sk_X509_NAME_pop_free(s->s3->tmp.peer_ca_names, X509_NAME_free);
+    s->s3->tmp.peer_ca_names = ca_sk;
+
+    return 1;
+
+ err:
+    sk_X509_NAME_pop_free(ca_sk, X509_NAME_free);
+    X509_NAME_free(xn);
+    return 0;
+}
+
+const STACK_OF(X509_NAME) *get_ca_names(SSL *s)
+{
+    const STACK_OF(X509_NAME) *ca_sk = NULL;;
+
+    if (s->server) {
+        ca_sk = SSL_get_client_CA_list(s);
+        if (ca_sk != NULL && sk_X509_NAME_num(ca_sk) == 0)
+            ca_sk = NULL;
+    }
+
+    if (ca_sk == NULL)
+        ca_sk = SSL_get0_CA_list(s);
+
+    return ca_sk;
+}
+
+int construct_ca_names(SSL *s, const STACK_OF(X509_NAME) *ca_sk, WPACKET *pkt)
+{
+    /* Start sub-packet for client CA list */
+    if (!WPACKET_start_sub_packet_u16(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_CA_NAMES,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    if (ca_sk != NULL) {
+        int i;
+
+        for (i = 0; i < sk_X509_NAME_num(ca_sk); i++) {
+            unsigned char *namebytes;
+            X509_NAME *name = sk_X509_NAME_value(ca_sk, i);
+            int namelen;
+
+            if (name == NULL
+                    || (namelen = i2d_X509_NAME(name, NULL)) < 0
+                    || !WPACKET_sub_allocate_bytes_u16(pkt, namelen,
+                                                       &namebytes)
+                    || i2d_X509_NAME(name, &namebytes) != namelen) {
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_CA_NAMES,
+                         ERR_R_INTERNAL_ERROR);
+                return 0;
+            }
+        }
+    }
+
+    if (!WPACKET_close(pkt)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_CA_NAMES,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    return 1;
+}
+
+/* Create a buffer containing data to be signed for server key exchange */
+size_t construct_key_exchange_tbs(SSL *s, unsigned char **ptbs,
+                                  const void *param, size_t paramlen)
+{
+    size_t tbslen = 2 * SSL3_RANDOM_SIZE + paramlen;
+    unsigned char *tbs = OPENSSL_malloc(tbslen);
+
+    if (tbs == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_KEY_EXCHANGE_TBS,
+                 ERR_R_MALLOC_FAILURE);
+        return 0;
+    }
+    memcpy(tbs, s->s3->client_random, SSL3_RANDOM_SIZE);
+    memcpy(tbs + SSL3_RANDOM_SIZE, s->s3->server_random, SSL3_RANDOM_SIZE);
+
+    memcpy(tbs + SSL3_RANDOM_SIZE * 2, param, paramlen);
+
+    *ptbs = tbs;
+    return tbslen;
+}
+
+/*
+ * Saves the current handshake digest for Post-Handshake Auth,
+ * Done after ClientFinished is processed, done exactly once
+ */
+int tls13_save_handshake_digest_for_pha(SSL *s)
+{
+    if (s->pha_dgst == NULL) {
+        if (!ssl3_digest_cached_records(s, 1))
+            /* SSLfatal() already called */
+            return 0;
+
+        s->pha_dgst = EVP_MD_CTX_new();
+        if (s->pha_dgst == NULL) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS13_SAVE_HANDSHAKE_DIGEST_FOR_PHA,
+                     ERR_R_INTERNAL_ERROR);
+            return 0;
+        }
+        if (!EVP_MD_CTX_copy_ex(s->pha_dgst,
+                                s->s3->handshake_dgst)) {
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                     SSL_F_TLS13_SAVE_HANDSHAKE_DIGEST_FOR_PHA,
+                     ERR_R_INTERNAL_ERROR);
+            EVP_MD_CTX_free(s->pha_dgst);
+            s->pha_dgst = NULL;
+            return 0;
+        }
+    }
+    return 1;
+}
+
+/*
+ * Restores the Post-Handshake Auth handshake digest
+ * Done just before sending/processing the Cert Request
+ */
+int tls13_restore_handshake_digest_for_pha(SSL *s)
+{
+    if (s->pha_dgst == NULL) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_TLS13_RESTORE_HANDSHAKE_DIGEST_FOR_PHA,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+    if (!EVP_MD_CTX_copy_ex(s->s3->handshake_dgst,
+                            s->pha_dgst)) {
+        SSLfatal(s, SSL_AD_INTERNAL_ERROR,
+                 SSL_F_TLS13_RESTORE_HANDSHAKE_DIGEST_FOR_PHA,
+                 ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+    return 1;
+}