text: /*
   * Copyright 1995-2020 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 Apache License 2.0 (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 "../ssl_local.h"
  #include "statem_local.h"
  #include "internal/constant_time.h"
  #include "internal/cryptlib.h"
  #include <openssl/buffer.h>
  #include <openssl/rand.h>
  #include <openssl/objects.h>
  #include <openssl/evp.h>
  #include <openssl/x509.h>
  #include <openssl/dh.h>
  #include <openssl/bn.h>
  #include <openssl/md5.h>
  #include <openssl/trace.h>
  #include <openssl/core_names.h>
  #include <openssl/asn1t.h>
  
  DEFINE_STACK_OF(X509)
  DEFINE_STACK_OF(SSL_COMP)
  DEFINE_STACK_OF_CONST(SSL_CIPHER)
  
  #define TICKET_NONCE_SIZE       8
  
  typedef struct {
    ASN1_TYPE *kxBlob;
    ASN1_TYPE *opaqueBlob;
  } GOST_KX_MESSAGE;
  
  DECLARE_ASN1_FUNCTIONS(GOST_KX_MESSAGE)
  
  ASN1_SEQUENCE(GOST_KX_MESSAGE) = {
    ASN1_SIMPLE(GOST_KX_MESSAGE,  kxBlob, ASN1_ANY),
    ASN1_OPT(GOST_KX_MESSAGE, opaqueBlob, ASN1_ANY),
  } ASN1_SEQUENCE_END(GOST_KX_MESSAGE)
  
  IMPLEMENT_ASN1_FUNCTIONS(GOST_KX_MESSAGE)
  
  static int tls_construct_encrypted_extensions(SSL *s, WPACKET *pkt);
  
  /*
   * ossl_statem_server13_read_transition() encapsulates the logic for the allowed
   * handshake state transitions when a TLSv1.3 server is reading messages from
   * the client. The message type that the client has sent is provided in |mt|.
   * The current state is in |s->statem.hand_state|.
   *
   * Return values are 1 for success (transition allowed) and  0 on error
   * (transition not allowed)
   */
  static int ossl_statem_server13_read_transition(SSL *s, int mt)
  {
      OSSL_STATEM *st = &s->statem;
  
      /*
       * Note: There is no case for TLS_ST_BEFORE because at that stage we have
       * not negotiated TLSv1.3 yet, so that case is handled by
       * ossl_statem_server_read_transition()
       */
      switch (st->hand_state) {
      default:
          break;
  
      case TLS_ST_EARLY_DATA:
          if (s->hello_retry_request == SSL_HRR_PENDING) {
              if (mt == SSL3_MT_CLIENT_HELLO) {
                  st->hand_state = TLS_ST_SR_CLNT_HELLO;
                  return 1;
              }
              break;
          } else if (s->ext.early_data == SSL_EARLY_DATA_ACCEPTED) {
              if (mt == SSL3_MT_END_OF_EARLY_DATA) {
                  st->hand_state = TLS_ST_SR_END_OF_EARLY_DATA;
                  return 1;
              }
              break;
          }
          /* Fall through */
  
      case TLS_ST_SR_END_OF_EARLY_DATA:
      case TLS_ST_SW_FINISHED:
          if (s->s3.tmp.cert_request) {
              if (mt == SSL3_MT_CERTIFICATE) {
                  st->hand_state = TLS_ST_SR_CERT;
                  return 1;
              }
          } else {
              if (mt == SSL3_MT_FINISHED) {
                  st->hand_state = TLS_ST_SR_FINISHED;
                  return 1;
              }
          }
          break;
  
      case TLS_ST_SR_CERT:
          if (s->session->peer == NULL) {
              if (mt == SSL3_MT_FINISHED) {
                  st->hand_state = TLS_ST_SR_FINISHED;
                  return 1;
              }
          } else {
              if (mt == SSL3_MT_CERTIFICATE_VERIFY) {
                  st->hand_state = TLS_ST_SR_CERT_VRFY;
                  return 1;
              }
          }
          break;
  
      case TLS_ST_SR_CERT_VRFY:
          if (mt == SSL3_MT_FINISHED) {
              st->hand_state = TLS_ST_SR_FINISHED;
              return 1;
          }
          break;
  
      case TLS_ST_OK:
          /*
           * Its never ok to start processing handshake messages in the middle of
           * early data (i.e. before we've received the end of early data alert)
           */
          if (s->early_data_state == SSL_EARLY_DATA_READING)
              break;
  
          if (mt == SSL3_MT_CERTIFICATE
                  && s->post_handshake_auth == SSL_PHA_REQUESTED) {
              st->hand_state = TLS_ST_SR_CERT;
              return 1;
          }
  
          if (mt == SSL3_MT_KEY_UPDATE) {
              st->hand_state = TLS_ST_SR_KEY_UPDATE;
              return 1;
          }
          break;
      }
  
      /* No valid transition found */
      return 0;
  }
  
  /*
   * ossl_statem_server_read_transition() encapsulates the logic for the allowed
   * handshake state transitions when the server is reading messages from the
   * client. The message type that the client has sent is provided in |mt|. The
   * current state is in |s->statem.hand_state|.
   *
   * Return values are 1 for success (transition allowed) and  0 on error
   * (transition not allowed)
   */
  int ossl_statem_server_read_transition(SSL *s, int mt)
  {
      OSSL_STATEM *st = &s->statem;
  
      if (SSL_IS_TLS13(s)) {
          if (!ossl_statem_server13_read_transition(s, mt))
              goto err;
          return 1;
      }
  
      switch (st->hand_state) {
      default:
          break;
  
      case TLS_ST_BEFORE:
      case TLS_ST_OK:
      case DTLS_ST_SW_HELLO_VERIFY_REQUEST:
          if (mt == SSL3_MT_CLIENT_HELLO) {
              st->hand_state = TLS_ST_SR_CLNT_HELLO;
              return 1;
          }
          break;
  
      case TLS_ST_SW_SRVR_DONE:
          /*
           * If we get a CKE message after a ServerDone then either
           * 1) We didn't request a Certificate
           * OR
           * 2) If we did request one then
           *      a) We allow no Certificate to be returned
           *      AND
           *      b) We are running SSL3 (in TLS1.0+ the client must return a 0
           *         list if we requested a certificate)
           */
          if (mt == SSL3_MT_CLIENT_KEY_EXCHANGE) {
              if (s->s3.tmp.cert_request) {
                  if (s->version == SSL3_VERSION) {
                      if ((s->verify_mode & SSL_VERIFY_PEER)
                          && (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
                          /*
                           * This isn't an unexpected message as such - we're just
                           * not going to accept it because we require a client
                           * cert.
                           */
                          SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                                   SSL_F_OSSL_STATEM_SERVER_READ_TRANSITION,
                                   SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
                          return 0;
                      }
                      st->hand_state = TLS_ST_SR_KEY_EXCH;
                      return 1;
                  }
              } else {
                  st->hand_state = TLS_ST_SR_KEY_EXCH;
                  return 1;
              }
          } else if (s->s3.tmp.cert_request) {
              if (mt == SSL3_MT_CERTIFICATE) {
                  st->hand_state = TLS_ST_SR_CERT;
                  return 1;
              }
          }
          break;
  
      case TLS_ST_SR_CERT:
          if (mt == SSL3_MT_CLIENT_KEY_EXCHANGE) {
              st->hand_state = TLS_ST_SR_KEY_EXCH;
              return 1;
          }
          break;
  
      case TLS_ST_SR_KEY_EXCH:
          /*
           * We should only process a CertificateVerify message if we have
           * received a Certificate from the client. If so then |s->session->peer|
           * will be non NULL. In some instances a CertificateVerify message is
           * not required even if the peer has sent a Certificate (e.g. such as in
           * the case of static DH). In that case |st->no_cert_verify| should be
           * set.
           */
          if (s->session->peer == NULL || st->no_cert_verify) {
              if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
                  /*
                   * For the ECDH ciphersuites when the client sends its ECDH
                   * pub key in a certificate, the CertificateVerify message is
                   * not sent. Also for GOST ciphersuites when the client uses
                   * its key from the certificate for key exchange.
                   */
                  st->hand_state = TLS_ST_SR_CHANGE;
                  return 1;
              }
          } else {
              if (mt == SSL3_MT_CERTIFICATE_VERIFY) {
                  st->hand_state = TLS_ST_SR_CERT_VRFY;
                  return 1;
              }
          }
          break;
  
      case TLS_ST_SR_CERT_VRFY:
          if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
              st->hand_state = TLS_ST_SR_CHANGE;
              return 1;
          }
          break;
  
      case TLS_ST_SR_CHANGE:
  #ifndef OPENSSL_NO_NEXTPROTONEG
          if (s->s3.npn_seen) {
              if (mt == SSL3_MT_NEXT_PROTO) {
                  st->hand_state = TLS_ST_SR_NEXT_PROTO;
                  return 1;
              }
          } else {
  #endif
              if (mt == SSL3_MT_FINISHED) {
                  st->hand_state = TLS_ST_SR_FINISHED;
                  return 1;
              }
  #ifndef OPENSSL_NO_NEXTPROTONEG
          }
  #endif
          break;
  
  #ifndef OPENSSL_NO_NEXTPROTONEG
      case TLS_ST_SR_NEXT_PROTO:
          if (mt == SSL3_MT_FINISHED) {
              st->hand_state = TLS_ST_SR_FINISHED;
              return 1;
          }
          break;
  #endif
  
      case TLS_ST_SW_FINISHED:
          if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
              st->hand_state = TLS_ST_SR_CHANGE;
              return 1;
          }
          break;
      }
  
   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_SERVER_READ_TRANSITION,
               SSL_R_UNEXPECTED_MESSAGE);
      return 0;
  }
  
  /*
   * Should we send a ServerKeyExchange message?
   *
   * Valid return values are:
   *   1: Yes
   *   0: No
   */
  static int send_server_key_exchange(SSL *s)
  {
      unsigned long alg_k = s->s3.tmp.new_cipher->algorithm_mkey;
  
      /*
       * only send a ServerKeyExchange if DH or fortezza but we have a
       * sign only certificate PSK: may send PSK identity hints For
       * ECC ciphersuites, we send a serverKeyExchange message only if
       * the cipher suite is either ECDH-anon or ECDHE. In other cases,
       * the server certificate contains the server's public key for
       * key exchange.
       */
      if (alg_k & (SSL_kDHE | SSL_kECDHE)
          /*
           * PSK: send ServerKeyExchange if PSK identity hint if
           * provided
           */
  #ifndef OPENSSL_NO_PSK
          /* Only send SKE if we have identity hint for plain PSK */
          || ((alg_k & (SSL_kPSK | SSL_kRSAPSK))
              && s->cert->psk_identity_hint)
          /* For other PSK always send SKE */
          || (alg_k & (SSL_PSK & (SSL_kDHEPSK | SSL_kECDHEPSK)))
  #endif
  #ifndef OPENSSL_NO_SRP
          /* SRP: send ServerKeyExchange */
          || (alg_k & SSL_kSRP)
  #endif
          ) {
          return 1;
      }
  
      return 0;
  }
  
  /*
   * Should we send a CertificateRequest message?
   *
   * Valid return values are:
   *   1: Yes
   *   0: No
   */
  int send_certificate_request(SSL *s)
  {
      if (
             /* don't request cert unless asked for it: */
             s->verify_mode & SSL_VERIFY_PEER
             /*
              * don't request if post-handshake-only unless doing
              * post-handshake in TLSv1.3:
              */
             && (!SSL_IS_TLS13(s) || !(s->verify_mode & SSL_VERIFY_POST_HANDSHAKE)
                 || s->post_handshake_auth == SSL_PHA_REQUEST_PENDING)
             /*
              * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
              * a second time:
              */
             && (s->certreqs_sent < 1 ||
                 !(s->verify_mode & SSL_VERIFY_CLIENT_ONCE))
             /*
              * never request cert in anonymous ciphersuites (see
              * section "Certificate request" in SSL 3 drafts and in
              * RFC 2246):
              */
             && (!(s->s3.tmp.new_cipher->algorithm_auth & SSL_aNULL)
                 /*
                  * ... except when the application insists on
                  * verification (against the specs, but statem_clnt.c accepts
                  * this for SSL 3)
                  */
                 || (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))
             /* don't request certificate for SRP auth */
             && !(s->s3.tmp.new_cipher->algorithm_auth & SSL_aSRP)
             /*
              * With normal PSK Certificates and Certificate Requests
              * are omitted
              */
             && !(s->s3.tmp.new_cipher->algorithm_auth & SSL_aPSK)) {
          return 1;
      }
  
      return 0;
  }
  
  /*
   * ossl_statem_server13_write_transition() works out what handshake state to
   * move to next when a TLSv1.3 server is writing messages to be sent to the
   * client.
   */
  static WRITE_TRAN ossl_statem_server13_write_transition(SSL *s)
  {
      OSSL_STATEM *st = &s->statem;
  
      /*
       * No case for TLS_ST_BEFORE, because at that stage we have not negotiated
       * TLSv1.3 yet, so that is handled by ossl_statem_server_write_transition()
       */
  
      switch (st->hand_state) {
      default:
          /* Shouldn't happen */
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_OSSL_STATEM_SERVER13_WRITE_TRANSITION,
                   ERR_R_INTERNAL_ERROR);
          return WRITE_TRAN_ERROR;
  
      case TLS_ST_OK:
          if (s->key_update != SSL_KEY_UPDATE_NONE) {
              st->hand_state = TLS_ST_SW_KEY_UPDATE;
              return WRITE_TRAN_CONTINUE;
          }
          if (s->post_handshake_auth == SSL_PHA_REQUEST_PENDING) {
              st->hand_state = TLS_ST_SW_CERT_REQ;
              return WRITE_TRAN_CONTINUE;
          }
          if (s->ext.extra_tickets_expected > 0) {
              st->hand_state = TLS_ST_SW_SESSION_TICKET;
              return WRITE_TRAN_CONTINUE;
          }
          /* Try to read from the client instead */
          return WRITE_TRAN_FINISHED;
  
      case TLS_ST_SR_CLNT_HELLO:
          st->hand_state = TLS_ST_SW_SRVR_HELLO;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_SRVR_HELLO:
          if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0
                  && s->hello_retry_request != SSL_HRR_COMPLETE)
              st->hand_state = TLS_ST_SW_CHANGE;
          else if (s->hello_retry_request == SSL_HRR_PENDING)
              st->hand_state = TLS_ST_EARLY_DATA;
          else
              st->hand_state = TLS_ST_SW_ENCRYPTED_EXTENSIONS;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_CHANGE:
          if (s->hello_retry_request == SSL_HRR_PENDING)
              st->hand_state = TLS_ST_EARLY_DATA;
          else
              st->hand_state = TLS_ST_SW_ENCRYPTED_EXTENSIONS;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_ENCRYPTED_EXTENSIONS:
          if (s->hit)
              st->hand_state = TLS_ST_SW_FINISHED;
          else if (send_certificate_request(s))
              st->hand_state = TLS_ST_SW_CERT_REQ;
          else
              st->hand_state = TLS_ST_SW_CERT;
  
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_CERT_REQ:
          if (s->post_handshake_auth == SSL_PHA_REQUEST_PENDING) {
              s->post_handshake_auth = SSL_PHA_REQUESTED;
              st->hand_state = TLS_ST_OK;
          } else {
              st->hand_state = TLS_ST_SW_CERT;
          }
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_CERT:
          st->hand_state = TLS_ST_SW_CERT_VRFY;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_CERT_VRFY:
          st->hand_state = TLS_ST_SW_FINISHED;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_FINISHED:
          st->hand_state = TLS_ST_EARLY_DATA;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_EARLY_DATA:
          return WRITE_TRAN_FINISHED;
  
      case TLS_ST_SR_FINISHED:
          /*
           * Technically we have finished the handshake at this point, but we're
           * going to remain "in_init" for now and write out any session tickets
           * immediately.
           */
          if (s->post_handshake_auth == SSL_PHA_REQUESTED) {
              s->post_handshake_auth = SSL_PHA_EXT_RECEIVED;
          } else if (!s->ext.ticket_expected) {
              /*
               * If we're not going to renew the ticket then we just finish the
               * handshake at this point.
               */
              st->hand_state = TLS_ST_OK;
              return WRITE_TRAN_CONTINUE;
          }
          if (s->num_tickets > s->sent_tickets)
              st->hand_state = TLS_ST_SW_SESSION_TICKET;
          else
              st->hand_state = TLS_ST_OK;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SR_KEY_UPDATE:
      case TLS_ST_SW_KEY_UPDATE:
          st->hand_state = TLS_ST_OK;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_SESSION_TICKET:
          /* In a resumption we only ever send a maximum of one new ticket.
           * Following an initial handshake we send the number of tickets we have
           * been configured for.
           */
          if (!SSL_IS_FIRST_HANDSHAKE(s) && s->ext.extra_tickets_expected > 0) {
              return WRITE_TRAN_CONTINUE;
          } else if (s->hit || s->num_tickets <= s->sent_tickets) {
              /* We've written enough tickets out. */
              st->hand_state = TLS_ST_OK;
          }
          return WRITE_TRAN_CONTINUE;
      }
  }
  
  /*
   * ossl_statem_server_write_transition() works out what handshake state to move
   * to next when the server is writing messages to be sent to the client.
   */
  WRITE_TRAN ossl_statem_server_write_transition(SSL *s)
  {
      OSSL_STATEM *st = &s->statem;
  
      /*
       * Note that before the 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_server13_write_transition(s);
  
      switch (st->hand_state) {
      default:
          /* Shouldn't happen */
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_OSSL_STATEM_SERVER_WRITE_TRANSITION,
                   ERR_R_INTERNAL_ERROR);
          return WRITE_TRAN_ERROR;
  
      case TLS_ST_OK:
          if (st->request_state == TLS_ST_SW_HELLO_REQ) {
              /* We must be trying to renegotiate */
              st->hand_state = TLS_ST_SW_HELLO_REQ;
              st->request_state = TLS_ST_BEFORE;
              return WRITE_TRAN_CONTINUE;
          }
          /* Must be an incoming ClientHello */
          if (!tls_setup_handshake(s)) {
              /* SSLfatal() already called */
              return WRITE_TRAN_ERROR;
          }
          /* Fall through */
  
      case TLS_ST_BEFORE:
          /* Just go straight to trying to read from the client */
          return WRITE_TRAN_FINISHED;
  
      case TLS_ST_SW_HELLO_REQ:
          st->hand_state = TLS_ST_OK;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SR_CLNT_HELLO:
          if (SSL_IS_DTLS(s) && !s->d1->cookie_verified
              && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE)) {
              st->hand_state = DTLS_ST_SW_HELLO_VERIFY_REQUEST;
          } else if (s->renegotiate == 0 && !SSL_IS_FIRST_HANDSHAKE(s)) {
              /* We must have rejected the renegotiation */
              st->hand_state = TLS_ST_OK;
              return WRITE_TRAN_CONTINUE;
          } else {
              st->hand_state = TLS_ST_SW_SRVR_HELLO;
          }
          return WRITE_TRAN_CONTINUE;
  
      case DTLS_ST_SW_HELLO_VERIFY_REQUEST:
          return WRITE_TRAN_FINISHED;
  
      case TLS_ST_SW_SRVR_HELLO:
          if (s->hit) {
              if (s->ext.ticket_expected)
                  st->hand_state = TLS_ST_SW_SESSION_TICKET;
              else
                  st->hand_state = TLS_ST_SW_CHANGE;
          } else {
              /* Check if it is anon DH or anon ECDH, */
              /* normal PSK or SRP */
              if (!(s->s3.tmp.new_cipher->algorithm_auth &
                    (SSL_aNULL | SSL_aSRP | SSL_aPSK))) {
                  st->hand_state = TLS_ST_SW_CERT;
              } else if (send_server_key_exchange(s)) {
                  st->hand_state = TLS_ST_SW_KEY_EXCH;
              } else if (send_certificate_request(s)) {
                  st->hand_state = TLS_ST_SW_CERT_REQ;
              } else {
                  st->hand_state = TLS_ST_SW_SRVR_DONE;
              }
          }
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_CERT:
          if (s->ext.status_expected) {
              st->hand_state = TLS_ST_SW_CERT_STATUS;
              return WRITE_TRAN_CONTINUE;
          }
          /* Fall through */
  
      case TLS_ST_SW_CERT_STATUS:
          if (send_server_key_exchange(s)) {
              st->hand_state = TLS_ST_SW_KEY_EXCH;
              return WRITE_TRAN_CONTINUE;
          }
          /* Fall through */
  
      case TLS_ST_SW_KEY_EXCH:
          if (send_certificate_request(s)) {
              st->hand_state = TLS_ST_SW_CERT_REQ;
              return WRITE_TRAN_CONTINUE;
          }
          /* Fall through */
  
      case TLS_ST_SW_CERT_REQ:
          st->hand_state = TLS_ST_SW_SRVR_DONE;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_SRVR_DONE:
          return WRITE_TRAN_FINISHED;
  
      case TLS_ST_SR_FINISHED:
          if (s->hit) {
              st->hand_state = TLS_ST_OK;
              return WRITE_TRAN_CONTINUE;
          } else if (s->ext.ticket_expected) {
              st->hand_state = TLS_ST_SW_SESSION_TICKET;
          } else {
              st->hand_state = TLS_ST_SW_CHANGE;
          }
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_SESSION_TICKET:
          st->hand_state = TLS_ST_SW_CHANGE;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_CHANGE:
          st->hand_state = TLS_ST_SW_FINISHED;
          return WRITE_TRAN_CONTINUE;
  
      case TLS_ST_SW_FINISHED:
          if (s->hit) {
              return WRITE_TRAN_FINISHED;
          }
          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 server to the client.
   */
  WORK_STATE ossl_statem_server_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_SW_HELLO_REQ:
          s->shutdown = 0;
          if (SSL_IS_DTLS(s))
              dtls1_clear_sent_buffer(s);
          break;
  
      case DTLS_ST_SW_HELLO_VERIFY_REQUEST:
          s->shutdown = 0;
          if (SSL_IS_DTLS(s)) {
              dtls1_clear_sent_buffer(s);
              /* We don't buffer this message so don't use the timer */
              st->use_timer = 0;
          }
          break;
  
      case TLS_ST_SW_SRVR_HELLO:
          if (SSL_IS_DTLS(s)) {
              /*
               * Messages we write from now on should be buffered and
               * retransmitted if necessary, so we need to use the timer now
               */
              st->use_timer = 1;
          }
          break;
  
      case TLS_ST_SW_SRVR_DONE:
  #ifndef OPENSSL_NO_SCTP
          if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
              /* Calls SSLfatal() as required */
              return dtls_wait_for_dry(s);
          }
  #endif
          return WORK_FINISHED_CONTINUE;
  
      case TLS_ST_SW_SESSION_TICKET:
          if (SSL_IS_TLS13(s) && s->sent_tickets == 0
                  && s->ext.extra_tickets_expected == 0) {
              /*
               * Actually this is the end of the handshake, but we're going
               * straight into writing the session ticket out. So we finish off
               * the handshake, but keep the various buffers active.
               *
               * Calls SSLfatal as required.
               */
              return tls_finish_handshake(s, wst, 0, 0);
          }
          if (SSL_IS_DTLS(s)) {
              /*
               * We're into the last flight. We don't retransmit the last flight
               * unless we need to, so we don't use the timer
               */
              st->use_timer = 0;
          }
          break;
  
      case TLS_ST_SW_CHANGE:
          if (SSL_IS_TLS13(s))
              break;
          /* Writes to s->session are only safe for initial handshakes */
          if (s->session->cipher == NULL) {
              s->session->cipher = s->s3.tmp.new_cipher;
          } else if (s->session->cipher != s->s3.tmp.new_cipher) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_OSSL_STATEM_SERVER_PRE_WORK,
                       ERR_R_INTERNAL_ERROR);
              return WORK_ERROR;
          }
          if (!s->method->ssl3_enc->setup_key_block(s)) {
              /* SSLfatal() already called */
              return WORK_ERROR;
          }
          if (SSL_IS_DTLS(s)) {
              /*
               * We're into the last flight. We don't retransmit the last flight
               * unless we need to, so we don't use the timer. This might have
               * already been set to 0 if we sent a NewSessionTicket message,
               * but we'll set it again here in case we didn't.
               */
              st->use_timer = 0;
          }
          return WORK_FINISHED_CONTINUE;
  
      case TLS_ST_EARLY_DATA:
          if (s->early_data_state != SSL_EARLY_DATA_ACCEPTING
                  && (s->s3.flags & TLS1_FLAGS_STATELESS) == 0)
              return WORK_FINISHED_CONTINUE;
          /* Fall through */
  
      case TLS_ST_OK:
          /* Calls SSLfatal() as required */
          return tls_finish_handshake(s, wst, 1, 1);
      }
  
      return WORK_FINISHED_CONTINUE;
  }
  
  static ossl_inline int conn_is_closed(void)
  {
      switch (get_last_sys_error()) {
  #if defined(EPIPE)
      case EPIPE:
          return 1;
  #endif
  #if defined(ECONNRESET)
      case ECONNRESET:
          return 1;
  #endif
  #if defined(WSAECONNRESET)
      case WSAECONNRESET:
          return 1;
  #endif
      default:
          return 0;
      }
  }
  
  /*
   * Perform any work that needs to be done after sending a message from the
   * server to the client.
   */
  WORK_STATE ossl_statem_server_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_SW_HELLO_REQ:
          if (statem_flush(s) != 1)
              return WORK_MORE_A;
          if (!ssl3_init_finished_mac(s)) {
              /* SSLfatal() already called */
              return WORK_ERROR;
          }
          break;
  
      case DTLS_ST_SW_HELLO_VERIFY_REQUEST:
          if (statem_flush(s) != 1)
              return WORK_MORE_A;
          /* HelloVerifyRequest resets Finished MAC */
          if (s->version != DTLS1_BAD_VER && !ssl3_init_finished_mac(s)) {
              /* SSLfatal() already called */
              return WORK_ERROR;
          }
          /*
           * The next message should be another ClientHello which we need to
           * treat like it was the first packet
           */
          s->first_packet = 1;
          break;
  
      case TLS_ST_SW_SRVR_HELLO:
          if (SSL_IS_TLS13(s) && s->hello_retry_request == SSL_HRR_PENDING) {
              if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) == 0
                      && statem_flush(s) != 1)
                  return WORK_MORE_A;
              break;
          }
  #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_OSSL_STATEM_SERVER_POST_WORK,
                           ERR_R_INTERNAL_ERROR);
                  return WORK_ERROR;
              }
  
              BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
                       sizeof(sctpauthkey), sctpauthkey);
          }
  #endif
          if (!SSL_IS_TLS13(s)
                  || ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0
                      && s->hello_retry_request != SSL_HRR_COMPLETE))
              break;
          /* Fall through */
  
      case TLS_ST_SW_CHANGE:
          if (s->hello_retry_request == SSL_HRR_PENDING) {
              if (!statem_flush(s))
                  return WORK_MORE_A;
              break;
          }
  
          if (SSL_IS_TLS13(s)) {
              if (!s->method->ssl3_enc->setup_key_block(s)
                  || !s->method->ssl3_enc->change_cipher_state(s,
                          SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_SERVER_WRITE)) {
                  /* SSLfatal() already called */
                  return WORK_ERROR;
              }
  
              if (s->ext.early_data != SSL_EARLY_DATA_ACCEPTED
                  && !s->method->ssl3_enc->change_cipher_state(s,
                          SSL3_CC_HANDSHAKE |SSL3_CHANGE_CIPHER_SERVER_READ)) {
                  /* SSLfatal() already called */
                  return WORK_ERROR;
              }
              /*
               * We don't yet know whether the next record we are going to receive
               * is an unencrypted alert, an encrypted alert, or an encrypted
               * handshake message. We temporarily tolerate unencrypted alerts.
               */
              s->statem.enc_read_state = ENC_READ_STATE_ALLOW_PLAIN_ALERTS;
              break;
          }
  
  #ifndef OPENSSL_NO_SCTP
          if (SSL_IS_DTLS(s) && !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
          if (!s->method->ssl3_enc->change_cipher_state(s,
                                                        SSL3_CHANGE_CIPHER_SERVER_WRITE))
          {
              /* SSLfatal() already called */
              return WORK_ERROR;
          }
  
          if (SSL_IS_DTLS(s))
              dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
          break;
  
      case TLS_ST_SW_SRVR_DONE:
          if (statem_flush(s) != 1)
              return WORK_MORE_A;
          break;
  
      case TLS_ST_SW_FINISHED:
          if (statem_flush(s) != 1)
              return WORK_MORE_A;
  #ifndef OPENSSL_NO_SCTP
          if (SSL_IS_DTLS(s) && 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
          if (SSL_IS_TLS13(s)) {
              /* 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)
                  || !s->method->ssl3_enc->change_cipher_state(s,
                          SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_SERVER_WRITE))
              /* SSLfatal() already called */
              return WORK_ERROR;
          }
          break;
  
      case TLS_ST_SW_CERT_REQ:
          if (s->post_handshake_auth == SSL_PHA_REQUEST_PENDING) {
              if (statem_flush(s) != 1)
                  return WORK_MORE_A;
          }
          break;
  
      case TLS_ST_SW_KEY_UPDATE:
          if (statem_flush(s) != 1)
              return WORK_MORE_A;
          if (!tls13_update_key(s, 1)) {
              /* SSLfatal() already called */
              return WORK_ERROR;
          }
          break;
  
      case TLS_ST_SW_SESSION_TICKET:
          clear_sys_error();
          if (SSL_IS_TLS13(s) && statem_flush(s) != 1) {
              if (SSL_get_error(s, 0) == SSL_ERROR_SYSCALL
                      && conn_is_closed()) {
                  /*
                   * We ignore connection closed errors in TLSv1.3 when sending a
                   * NewSessionTicket and behave as if we were successful. This is
                   * so that we are still able to read data sent to us by a client
                   * that closes soon after the end of the handshake without
                   * waiting to read our post-handshake NewSessionTickets.
                   */
                  s->rwstate = SSL_NOTHING;
                  break;
              }
  
              return WORK_MORE_A;
          }
          break;
      }
  
      return WORK_FINISHED_CONTINUE;
  }
  
  /*
   * Get the message construction function and message type for sending from the
   * server
   *
   * Valid return values are:
   *   1: Success
   *   0: Error
   */
  int ossl_statem_server_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_SERVER_CONSTRUCT_MESSAGE,
                   SSL_R_BAD_HANDSHAKE_STATE);
          return 0;
  
      case TLS_ST_SW_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 DTLS_ST_SW_HELLO_VERIFY_REQUEST:
          *confunc = dtls_construct_hello_verify_request;
          *mt = DTLS1_MT_HELLO_VERIFY_REQUEST;
          break;
  
      case TLS_ST_SW_HELLO_REQ:
          /* No construction function needed */
          *confunc = NULL;
          *mt = SSL3_MT_HELLO_REQUEST;
          break;
  
      case TLS_ST_SW_SRVR_HELLO:
          *confunc = tls_construct_server_hello;
          *mt = SSL3_MT_SERVER_HELLO;
          break;
  
      case TLS_ST_SW_CERT:
          *confunc = tls_construct_server_certificate;
          *mt = SSL3_MT_CERTIFICATE;
          break;
  
      case TLS_ST_SW_CERT_VRFY:
          *confunc = tls_construct_cert_verify;
          *mt = SSL3_MT_CERTIFICATE_VERIFY;
          break;
  
  
      case TLS_ST_SW_KEY_EXCH:
          *confunc = tls_construct_server_key_exchange;
          *mt = SSL3_MT_SERVER_KEY_EXCHANGE;
          break;
  
      case TLS_ST_SW_CERT_REQ:
          *confunc = tls_construct_certificate_request;
          *mt = SSL3_MT_CERTIFICATE_REQUEST;
          break;
  
      case TLS_ST_SW_SRVR_DONE:
          *confunc = tls_construct_server_done;
          *mt = SSL3_MT_SERVER_DONE;
          break;
  
      case TLS_ST_SW_SESSION_TICKET:
          *confunc = tls_construct_new_session_ticket;
          *mt = SSL3_MT_NEWSESSION_TICKET;
          break;
  
      case TLS_ST_SW_CERT_STATUS:
          *confunc = tls_construct_cert_status;
          *mt = SSL3_MT_CERTIFICATE_STATUS;
          break;
  
      case TLS_ST_SW_FINISHED:
          *confunc = tls_construct_finished;
          *mt = SSL3_MT_FINISHED;
          break;
  
      case TLS_ST_EARLY_DATA:
          *confunc = NULL;
          *mt = SSL3_MT_DUMMY;
          break;
  
      case TLS_ST_SW_ENCRYPTED_EXTENSIONS:
          *confunc = tls_construct_encrypted_extensions;
          *mt = SSL3_MT_ENCRYPTED_EXTENSIONS;
          break;
  
      case TLS_ST_SW_KEY_UPDATE:
          *confunc = tls_construct_key_update;
          *mt = SSL3_MT_KEY_UPDATE;
          break;
      }
  
      return 1;
  }
  
  /*
   * Maximum size (excluding the Handshake header) of a ClientHello message,
   * calculated as follows:
   *
   *  2 + # client_version
   *  32 + # only valid length for random
   *  1 + # length of session_id
   *  32 + # maximum size for session_id
   *  2 + # length of cipher suites
   *  2^16-2 + # maximum length of cipher suites array
   *  1 + # length of compression_methods
   *  2^8-1 + # maximum length of compression methods
   *  2 + # length of extensions
   *  2^16-1 # maximum length of extensions
   */
  #define CLIENT_HELLO_MAX_LENGTH         131396
  
  #define CLIENT_KEY_EXCH_MAX_LENGTH      2048
  #define NEXT_PROTO_MAX_LENGTH           514
  
  /*
   * Returns the maximum allowed length for the current message that we are
   * reading. Excludes the message header.
   */
  size_t ossl_statem_server_max_message_size(SSL *s)
  {
      OSSL_STATEM *st = &s->statem;
  
      switch (st->hand_state) {
      default:
          /* Shouldn't happen */
          return 0;
  
      case TLS_ST_SR_CLNT_HELLO:
          return CLIENT_HELLO_MAX_LENGTH;
  
      case TLS_ST_SR_END_OF_EARLY_DATA:
          return END_OF_EARLY_DATA_MAX_LENGTH;
  
      case TLS_ST_SR_CERT:
          return s->max_cert_list;
  
      case TLS_ST_SR_KEY_EXCH:
          return CLIENT_KEY_EXCH_MAX_LENGTH;
  
      case TLS_ST_SR_CERT_VRFY:
          return SSL3_RT_MAX_PLAIN_LENGTH;
  
  #ifndef OPENSSL_NO_NEXTPROTONEG
      case TLS_ST_SR_NEXT_PROTO:
          return NEXT_PROTO_MAX_LENGTH;
  #endif
  
      case TLS_ST_SR_CHANGE:
          return CCS_MAX_LENGTH;
  
      case TLS_ST_SR_FINISHED:
          return FINISHED_MAX_LENGTH;
  
      case TLS_ST_SR_KEY_UPDATE:
          return KEY_UPDATE_MAX_LENGTH;
      }
  }
  
  /*
   * Process a message that the server has received from the client.
   */
  MSG_PROCESS_RETURN ossl_statem_server_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_SERVER_PROCESS_MESSAGE,
                   ERR_R_INTERNAL_ERROR);
          return MSG_PROCESS_ERROR;
  
      case TLS_ST_SR_CLNT_HELLO:
          return tls_process_client_hello(s, pkt);
  
      case TLS_ST_SR_END_OF_EARLY_DATA:
          return tls_process_end_of_early_data(s, pkt);
  
      case TLS_ST_SR_CERT:
          return tls_process_client_certificate(s, pkt);
  
      case TLS_ST_SR_KEY_EXCH:
          return tls_process_client_key_exchange(s, pkt);
  
      case TLS_ST_SR_CERT_VRFY:
          return tls_process_cert_verify(s, pkt);
  
  #ifndef OPENSSL_NO_NEXTPROTONEG
      case TLS_ST_SR_NEXT_PROTO:
          return tls_process_next_proto(s, pkt);
  #endif
  
      case TLS_ST_SR_CHANGE:
          return tls_process_change_cipher_spec(s, pkt);
  
      case TLS_ST_SR_FINISHED:
          return tls_process_finished(s, pkt);
  
      case TLS_ST_SR_KEY_UPDATE:
          return tls_process_key_update(s, pkt);
  
      }
  }
  
  /*
   * Perform any further processing required following the receipt of a message
   * from the client
   */
  WORK_STATE ossl_statem_server_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_SERVER_POST_PROCESS_MESSAGE,
                   ERR_R_INTERNAL_ERROR);
          return WORK_ERROR;
  
      case TLS_ST_SR_CLNT_HELLO:
          return tls_post_process_client_hello(s, wst);
  
      case TLS_ST_SR_KEY_EXCH:
          return tls_post_process_client_key_exchange(s, wst);
      }
  }
  
  #ifndef OPENSSL_NO_SRP
  /* Returns 1 on success, 0 for retryable error, -1 for fatal error */
  static int ssl_check_srp_ext_ClientHello(SSL *s)
  {
      int ret;
      int al = SSL_AD_UNRECOGNIZED_NAME;
  
      if ((s->s3.tmp.new_cipher->algorithm_mkey & SSL_kSRP) &&
          (s->srp_ctx.TLS_ext_srp_username_callback != NULL)) {
          if (s->srp_ctx.login == NULL) {
              /*
               * RFC 5054 says SHOULD reject, we do so if There is no srp
               * login name
               */
              SSLfatal(s, SSL_AD_UNKNOWN_PSK_IDENTITY,
                       SSL_F_SSL_CHECK_SRP_EXT_CLIENTHELLO,
                       SSL_R_PSK_IDENTITY_NOT_FOUND);
              return -1;
          } else {
              ret = SSL_srp_server_param_with_username(s, &al);
              if (ret < 0)
                  return 0;
              if (ret == SSL3_AL_FATAL) {
                  SSLfatal(s, al, SSL_F_SSL_CHECK_SRP_EXT_CLIENTHELLO,
                           al == SSL_AD_UNKNOWN_PSK_IDENTITY
                           ? SSL_R_PSK_IDENTITY_NOT_FOUND
                           : SSL_R_CLIENTHELLO_TLSEXT);
                  return -1;
              }
          }
      }
      return 1;
  }
  #endif
  
  int dtls_raw_hello_verify_request(WPACKET *pkt, unsigned char *cookie,
                                    size_t cookie_len)
  {
      /* Always use DTLS 1.0 version: see RFC 6347 */
      if (!WPACKET_put_bytes_u16(pkt, DTLS1_VERSION)
              || !WPACKET_sub_memcpy_u8(pkt, cookie, cookie_len))
          return 0;
  
      return 1;
  }
  
  int dtls_construct_hello_verify_request(SSL *s, WPACKET *pkt)
  {
      unsigned int cookie_leni;
      if (s->ctx->app_gen_cookie_cb == NULL ||
          s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
                                    &cookie_leni) == 0 ||
          cookie_leni > 255) {
          SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_DTLS_CONSTRUCT_HELLO_VERIFY_REQUEST,
                   SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
          return 0;
      }
      s->d1->cookie_len = cookie_leni;
  
      if (!dtls_raw_hello_verify_request(pkt, s->d1->cookie,
                                                s->d1->cookie_len)) {
          SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_DTLS_CONSTRUCT_HELLO_VERIFY_REQUEST,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      return 1;
  }
  
  #ifndef OPENSSL_NO_EC
  /*-
   * ssl_check_for_safari attempts to fingerprint Safari using OS X
   * SecureTransport using the TLS extension block in |hello|.
   * Safari, since 10.6, sends exactly these extensions, in this order:
   *   SNI,
   *   elliptic_curves
   *   ec_point_formats
   *   signature_algorithms (for TLSv1.2 only)
   *
   * We wish to fingerprint Safari because they broke ECDHE-ECDSA support in 10.8,
   * but they advertise support. So enabling ECDHE-ECDSA ciphers breaks them.
   * Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from
   * 10.8..10.8.3 (which don't work).
   */
  static void ssl_check_for_safari(SSL *s, const CLIENTHELLO_MSG *hello)
  {
      static const unsigned char kSafariExtensionsBlock[] = {
          0x00, 0x0a,             /* elliptic_curves extension */
          0x00, 0x08,             /* 8 bytes */
          0x00, 0x06,             /* 6 bytes of curve ids */
          0x00, 0x17,             /* P-256 */
          0x00, 0x18,             /* P-384 */
          0x00, 0x19,             /* P-521 */
  
          0x00, 0x0b,             /* ec_point_formats */
          0x00, 0x02,             /* 2 bytes */
          0x01,                   /* 1 point format */
          0x00,                   /* uncompressed */
          /* The following is only present in TLS 1.2 */
          0x00, 0x0d,             /* signature_algorithms */
          0x00, 0x0c,             /* 12 bytes */
          0x00, 0x0a,             /* 10 bytes */
          0x05, 0x01,             /* SHA-384/RSA */
          0x04, 0x01,             /* SHA-256/RSA */
          0x02, 0x01,             /* SHA-1/RSA */
          0x04, 0x03,             /* SHA-256/ECDSA */
          0x02, 0x03,             /* SHA-1/ECDSA */
      };
      /* Length of the common prefix (first two extensions). */
      static const size_t kSafariCommonExtensionsLength = 18;
      unsigned int type;
      PACKET sni, tmppkt;
      size_t ext_len;
  
      tmppkt = hello->extensions;
  
      if (!PACKET_forward(&tmppkt, 2)
          || !PACKET_get_net_2(&tmppkt, &type)
          || !PACKET_get_length_prefixed_2(&tmppkt, &sni)) {
          return;
      }
  
      if (type != TLSEXT_TYPE_server_name)
          return;
  
      ext_len = TLS1_get_client_version(s) >= TLS1_2_VERSION ?
          sizeof(kSafariExtensionsBlock) : kSafariCommonExtensionsLength;
  
      s->s3.is_probably_safari = PACKET_equal(&tmppkt, kSafariExtensionsBlock,
                                               ext_len);
  }
  #endif                          /* !OPENSSL_NO_EC */
  
  MSG_PROCESS_RETURN tls_process_client_hello(SSL *s, PACKET *pkt)
  {
      /* |cookie| will only be initialized for DTLS. */
      PACKET session_id, compression, extensions, cookie;
      static const unsigned char null_compression = 0;
      CLIENTHELLO_MSG *clienthello = NULL;
  
      /* Check if this is actually an unexpected renegotiation ClientHello */
      if (s->renegotiate == 0 && !SSL_IS_FIRST_HANDSHAKE(s)) {
          if (!ossl_assert(!SSL_IS_TLS13(s))) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
          if ((s->options & SSL_OP_NO_RENEGOTIATION) != 0
                  || (!s->s3.send_connection_binding
                      && (s->options
                          & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) == 0)) {
              ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
              return MSG_PROCESS_FINISHED_READING;
          }
          s->renegotiate = 1;
          s->new_session = 1;
      }
  
      clienthello = OPENSSL_zalloc(sizeof(*clienthello));
      if (clienthello == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                   ERR_R_INTERNAL_ERROR);
          goto err;
      }
  
      /*
       * First, parse the raw ClientHello data into the CLIENTHELLO_MSG structure.
       */
      clienthello->isv2 = RECORD_LAYER_is_sslv2_record(&s->rlayer);
      PACKET_null_init(&cookie);
  
      if (clienthello->isv2) {
          unsigned int mt;
  
          if (!SSL_IS_FIRST_HANDSHAKE(s)
                  || s->hello_retry_request != SSL_HRR_NONE) {
              SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
                       SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_UNEXPECTED_MESSAGE);
              goto err;
          }
  
          /*-
           * An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2
           * header is sent directly on the wire, not wrapped as a TLS
           * record. Our record layer just processes the message length and passes
           * the rest right through. Its format is:
           * Byte  Content
           * 0-1   msg_length - decoded by the record layer
           * 2     msg_type - s->init_msg points here
           * 3-4   version
           * 5-6   cipher_spec_length
           * 7-8   session_id_length
           * 9-10  challenge_length
           * ...   ...
           */
  
          if (!PACKET_get_1(pkt, &mt)
              || mt != SSL2_MT_CLIENT_HELLO) {
              /*
               * Should never happen. We should have tested this in the record
               * layer in order to have determined that this is a SSLv2 record
               * in the first place
               */
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
      }
  
      if (!PACKET_get_net_2(pkt, &clienthello->legacy_version)) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                   SSL_R_LENGTH_TOO_SHORT);
          goto err;
      }
  
      /* Parse the message and load client random. */
      if (clienthello->isv2) {
          /*
           * Handle an SSLv2 backwards compatible ClientHello
           * Note, this is only for SSLv3+ using the backward compatible format.
           * Real SSLv2 is not supported, and is rejected below.
           */
          unsigned int ciphersuite_len, session_id_len, challenge_len;
          PACKET challenge;
  
          if (!PACKET_get_net_2(pkt, &ciphersuite_len)
              || !PACKET_get_net_2(pkt, &session_id_len)
              || !PACKET_get_net_2(pkt, &challenge_len)) {
              SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                       SSL_R_RECORD_LENGTH_MISMATCH);
              goto err;
          }
  
          if (session_id_len > SSL_MAX_SSL_SESSION_ID_LENGTH) {
              SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
                       SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_LENGTH_MISMATCH);
              goto err;
          }
  
          if (!PACKET_get_sub_packet(pkt, &clienthello->ciphersuites,
                                     ciphersuite_len)
              || !PACKET_copy_bytes(pkt, clienthello->session_id, session_id_len)
              || !PACKET_get_sub_packet(pkt, &challenge, challenge_len)
              /* No extensions. */
              || PACKET_remaining(pkt) != 0) {
              SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                       SSL_R_RECORD_LENGTH_MISMATCH);
              goto err;
          }
          clienthello->session_id_len = session_id_len;
  
          /* Load the client random and compression list. We use SSL3_RANDOM_SIZE
           * here rather than sizeof(clienthello->random) because that is the limit
           * for SSLv3 and it is fixed. It won't change even if
           * sizeof(clienthello->random) does.
           */
          challenge_len = challenge_len > SSL3_RANDOM_SIZE
                          ? SSL3_RANDOM_SIZE : challenge_len;
          memset(clienthello->random, 0, SSL3_RANDOM_SIZE);
          if (!PACKET_copy_bytes(&challenge,
                                 clienthello->random + SSL3_RANDOM_SIZE -
                                 challenge_len, challenge_len)
              /* Advertise only null compression. */
              || !PACKET_buf_init(&compression, &null_compression, 1)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
  
          PACKET_null_init(&clienthello->extensions);
      } else {
          /* Regular ClientHello. */
          if (!PACKET_copy_bytes(pkt, clienthello->random, SSL3_RANDOM_SIZE)
              || !PACKET_get_length_prefixed_1(pkt, &session_id)
              || !PACKET_copy_all(&session_id, clienthello->session_id,
                      SSL_MAX_SSL_SESSION_ID_LENGTH,
                      &clienthello->session_id_len)) {
              SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                       SSL_R_LENGTH_MISMATCH);
              goto err;
          }
  
          if (SSL_IS_DTLS(s)) {
              if (!PACKET_get_length_prefixed_1(pkt, &cookie)) {
                  SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                           SSL_R_LENGTH_MISMATCH);
                  goto err;
              }
              if (!PACKET_copy_all(&cookie, clienthello->dtls_cookie,
                                   DTLS1_COOKIE_LENGTH,
                                   &clienthello->dtls_cookie_len)) {
                  SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                           SSL_F_TLS_PROCESS_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
                  goto err;
              }
              /*
               * If we require cookies and this ClientHello doesn't contain one,
               * just return since we do not want to allocate any memory yet.
               * So check cookie length...
               */
              if (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) {
                  if (clienthello->dtls_cookie_len == 0) {
                      OPENSSL_free(clienthello);
                      return MSG_PROCESS_FINISHED_READING;
                  }
              }
          }
  
          if (!PACKET_get_length_prefixed_2(pkt, &clienthello->ciphersuites)) {
              SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                       SSL_R_LENGTH_MISMATCH);
              goto err;
          }
  
          if (!PACKET_get_length_prefixed_1(pkt, &compression)) {
              SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                       SSL_R_LENGTH_MISMATCH);
              goto err;
          }
  
          /* Could be empty. */
          if (PACKET_remaining(pkt) == 0) {
              PACKET_null_init(&clienthello->extensions);
          } else {
              if (!PACKET_get_length_prefixed_2(pkt, &clienthello->extensions)
                      || PACKET_remaining(pkt) != 0) {
                  SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                           SSL_R_LENGTH_MISMATCH);
                  goto err;
              }
          }
      }
  
      if (!PACKET_copy_all(&compression, clienthello->compressions,
                           MAX_COMPRESSIONS_SIZE,
                           &clienthello->compressions_len)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CLIENT_HELLO,
                   ERR_R_INTERNAL_ERROR);
          goto err;
      }
  
      /* Preserve the raw extensions PACKET for later use */
      extensions = clienthello->extensions;
      if (!tls_collect_extensions(s, &extensions, SSL_EXT_CLIENT_HELLO,
                                  &clienthello->pre_proc_exts,
                                  &clienthello->pre_proc_exts_len, 1)) {
          /* SSLfatal already been called */
          goto err;
      }
      s->clienthello = clienthello;
  
      return MSG_PROCESS_CONTINUE_PROCESSING;
  
   err:
      if (clienthello != NULL)
          OPENSSL_free(clienthello->pre_proc_exts);
      OPENSSL_free(clienthello);
  
      return MSG_PROCESS_ERROR;
  }
  
  static int tls_early_post_process_client_hello(SSL *s)
  {
      unsigned int j;
      int i, al = SSL_AD_INTERNAL_ERROR;
      int protverr;
      size_t loop;
      unsigned long id;
  #ifndef OPENSSL_NO_COMP
      SSL_COMP *comp = NULL;
  #endif
      const SSL_CIPHER *c;
      STACK_OF(SSL_CIPHER) *ciphers = NULL;
      STACK_OF(SSL_CIPHER) *scsvs = NULL;
      CLIENTHELLO_MSG *clienthello = s->clienthello;
      DOWNGRADE dgrd = DOWNGRADE_NONE;
  
      /* Finished parsing the ClientHello, now we can start processing it */
      /* Give the ClientHello callback a crack at things */
      if (s->ctx->client_hello_cb != NULL) {
          /* A failure in the ClientHello callback terminates the connection. */
          switch (s->ctx->client_hello_cb(s, &al, s->ctx->client_hello_cb_arg)) {
          case SSL_CLIENT_HELLO_SUCCESS:
              break;
          case SSL_CLIENT_HELLO_RETRY:
              s->rwstate = SSL_CLIENT_HELLO_CB;
              return -1;
          case SSL_CLIENT_HELLO_ERROR:
          default:
              SSLfatal(s, al,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       SSL_R_CALLBACK_FAILED);
              goto err;
          }
      }
  
      /* Set up the client_random */
      memcpy(s->s3.client_random, clienthello->random, SSL3_RANDOM_SIZE);
  
      /* Choose the version */
  
      if (clienthello->isv2) {
          if (clienthello->legacy_version == SSL2_VERSION
                  || (clienthello->legacy_version & 0xff00)
                     != (SSL3_VERSION_MAJOR << 8)) {
              /*
               * This is real SSLv2 or something completely unknown. We don't
               * support it.
               */
              SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       SSL_R_UNKNOWN_PROTOCOL);
              goto err;
          }
          /* SSLv3/TLS */
          s->client_version = clienthello->legacy_version;
      }
      /*
       * Do SSL/TLS version negotiation if applicable. For DTLS we just check
       * versions are potentially compatible. Version negotiation comes later.
       */
      if (!SSL_IS_DTLS(s)) {
          protverr = ssl_choose_server_version(s, clienthello, &dgrd);
      } else if (s->method->version != DTLS_ANY_VERSION &&
                 DTLS_VERSION_LT((int)clienthello->legacy_version, s->version)) {
          protverr = SSL_R_VERSION_TOO_LOW;
      } else {
          protverr = 0;
      }
  
      if (protverr) {
          if (SSL_IS_FIRST_HANDSHAKE(s)) {
              /* like ssl3_get_record, send alert using remote version number */
              s->version = s->client_version = clienthello->legacy_version;
          }
          SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
                   SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO, protverr);
          goto err;
      }
  
      /* TLSv1.3 specifies that a ClientHello must end 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_EARLY_POST_PROCESS_CLIENT_HELLO,
                   SSL_R_NOT_ON_RECORD_BOUNDARY);
          goto err;
      }
  
      if (SSL_IS_DTLS(s)) {
          /* Empty cookie was already handled above by returning early. */
          if (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) {
              if (s->ctx->app_verify_cookie_cb != NULL) {
                  if (s->ctx->app_verify_cookie_cb(s, clienthello->dtls_cookie,
                          clienthello->dtls_cookie_len) == 0) {
                      SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                               SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                               SSL_R_COOKIE_MISMATCH);
                      goto err;
                      /* else cookie verification succeeded */
                  }
                  /* default verification */
              } else if (s->d1->cookie_len != clienthello->dtls_cookie_len
                      || memcmp(clienthello->dtls_cookie, s->d1->cookie,
                                s->d1->cookie_len) != 0) {
                  SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                           SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                           SSL_R_COOKIE_MISMATCH);
                  goto err;
              }
              s->d1->cookie_verified = 1;
          }
          if (s->method->version == DTLS_ANY_VERSION) {
              protverr = ssl_choose_server_version(s, clienthello, &dgrd);
              if (protverr != 0) {
                  s->version = s->client_version;
                  SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
                           SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO, protverr);
                  goto err;
              }
          }
      }
  
      s->hit = 0;
  
      if (!ssl_cache_cipherlist(s, &clienthello->ciphersuites,
                                clienthello->isv2) ||
          !bytes_to_cipher_list(s, &clienthello->ciphersuites, &ciphers, &scsvs,
                                clienthello->isv2, 1)) {
          /* SSLfatal() already called */
          goto err;
      }
  
      s->s3.send_connection_binding = 0;
      /* Check what signalling cipher-suite values were received. */
      if (scsvs != NULL) {
          for(i = 0; i < sk_SSL_CIPHER_num(scsvs); i++) {
              c = sk_SSL_CIPHER_value(scsvs, i);
              if (SSL_CIPHER_get_id(c) == SSL3_CK_SCSV) {
                  if (s->renegotiate) {
                      /* SCSV is fatal if renegotiating */
                      SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                               SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                               SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING);
                      goto err;
                  }
                  s->s3.send_connection_binding = 1;
              } else if (SSL_CIPHER_get_id(c) == SSL3_CK_FALLBACK_SCSV &&
                         !ssl_check_version_downgrade(s)) {
                  /*
                   * This SCSV indicates that the client previously tried
                   * a higher version.  We should fail if the current version
                   * is an unexpected downgrade, as that indicates that the first
                   * connection may have been tampered with in order to trigger
                   * an insecure downgrade.
                   */
                  SSLfatal(s, SSL_AD_INAPPROPRIATE_FALLBACK,
                           SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                           SSL_R_INAPPROPRIATE_FALLBACK);
                  goto err;
              }
          }
      }
  
      /* For TLSv1.3 we must select the ciphersuite *before* session resumption */
      if (SSL_IS_TLS13(s)) {
          const SSL_CIPHER *cipher =
              ssl3_choose_cipher(s, ciphers, SSL_get_ciphers(s));
  
          if (cipher == NULL) {
              SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       SSL_R_NO_SHARED_CIPHER);
              goto err;
          }
          if (s->hello_retry_request == SSL_HRR_PENDING
                  && (s->s3.tmp.new_cipher == NULL
                      || s->s3.tmp.new_cipher->id != cipher->id)) {
              /*
               * A previous HRR picked a different ciphersuite to the one we
               * just selected. Something must have changed.
               */
              SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       SSL_R_BAD_CIPHER);
              goto err;
          }
          s->s3.tmp.new_cipher = cipher;
      }
  
      /* We need to do this before getting the session */
      if (!tls_parse_extension(s, TLSEXT_IDX_extended_master_secret,
                               SSL_EXT_CLIENT_HELLO,
                               clienthello->pre_proc_exts, NULL, 0)) {
          /* SSLfatal() already called */
          goto err;
      }
  
      /*
       * We don't allow resumption in a backwards compatible ClientHello.
       * TODO(openssl-team): in TLS1.1+, session_id MUST be empty.
       *
       * Versions before 0.9.7 always allow clients to resume sessions in
       * renegotiation. 0.9.7 and later allow this by default, but optionally
       * ignore resumption requests with flag
       * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION (it's a new flag rather
       * than a change to default behavior so that applications relying on
       * this for security won't even compile against older library versions).
       * 1.0.1 and later also have a function SSL_renegotiate_abbreviated() to
       * request renegotiation but not a new session (s->new_session remains
       * unset): for servers, this essentially just means that the
       * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION setting will be
       * ignored.
       */
      if (clienthello->isv2 ||
          (s->new_session &&
           (s->options & SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION))) {
          if (!ssl_get_new_session(s, 1)) {
              /* SSLfatal() already called */
              goto err;
          }
      } else {
          i = ssl_get_prev_session(s, clienthello);
          if (i == 1) {
              /* previous session */
              s->hit = 1;
          } else if (i == -1) {
              /* SSLfatal() already called */
              goto err;
          } else {
              /* i == 0 */
              if (!ssl_get_new_session(s, 1)) {
                  /* SSLfatal() already called */
                  goto err;
              }
          }
      }
  
      if (SSL_IS_TLS13(s)) {
          memcpy(s->tmp_session_id, s->clienthello->session_id,
                 s->clienthello->session_id_len);
          s->tmp_session_id_len = s->clienthello->session_id_len;
      }
  
      /*
       * If it is a hit, check that the cipher is in the list. In TLSv1.3 we check
       * ciphersuite compatibility with the session as part of resumption.
       */
      if (!SSL_IS_TLS13(s) && s->hit) {
          j = 0;
          id = s->session->cipher->id;
  
          OSSL_TRACE_BEGIN(TLS_CIPHER) {
              BIO_printf(trc_out, "client sent %d ciphers\n",
                         sk_SSL_CIPHER_num(ciphers));
          }
          for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
              c = sk_SSL_CIPHER_value(ciphers, i);
              if (trc_out != NULL)
                  BIO_printf(trc_out, "client [%2d of %2d]:%s\n", i,
                             sk_SSL_CIPHER_num(ciphers), SSL_CIPHER_get_name(c));
              if (c->id == id) {
                  j = 1;
                  break;
              }
          }
          if (j == 0) {
              /*
               * we need to have the cipher in the cipher list if we are asked
               * to reuse it
               */
              SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       SSL_R_REQUIRED_CIPHER_MISSING);
              OSSL_TRACE_CANCEL(TLS_CIPHER);
              goto err;
          }
          OSSL_TRACE_END(TLS_CIPHER);
      }
  
      for (loop = 0; loop < clienthello->compressions_len; loop++) {
          if (clienthello->compressions[loop] == 0)
              break;
      }
  
      if (loop >= clienthello->compressions_len) {
          /* no compress */
          SSLfatal(s, SSL_AD_DECODE_ERROR,
                   SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                   SSL_R_NO_COMPRESSION_SPECIFIED);
          goto err;
      }
  
  #ifndef OPENSSL_NO_EC
      if (s->options & SSL_OP_SAFARI_ECDHE_ECDSA_BUG)
          ssl_check_for_safari(s, clienthello);
  #endif                          /* !OPENSSL_NO_EC */
  
      /* TLS extensions */
      if (!tls_parse_all_extensions(s, SSL_EXT_CLIENT_HELLO,
                                    clienthello->pre_proc_exts, NULL, 0, 1)) {
          /* SSLfatal() already called */
          goto err;
      }
  
      /*
       * Check if we want to use external pre-shared secret for this handshake
       * for not reused session only. We need to generate server_random before
       * calling tls_session_secret_cb in order to allow SessionTicket
       * processing to use it in key derivation.
       */
      {
          unsigned char *pos;
          pos = s->s3.server_random;
          if (ssl_fill_hello_random(s, 1, pos, SSL3_RANDOM_SIZE, dgrd) <= 0) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
      }
  
      if (!s->hit
              && s->version >= TLS1_VERSION
              && !SSL_IS_TLS13(s)
              && !SSL_IS_DTLS(s)
              && s->ext.session_secret_cb) {
          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, ciphers,
                                       &pref_cipher,
                                       s->ext.session_secret_cb_arg)
                  && master_key_length > 0) {
              s->session->master_key_length = master_key_length;
              s->hit = 1;
              s->peer_ciphers = ciphers;
              s->session->verify_result = X509_V_OK;
  
              ciphers = NULL;
  
              /* check if some cipher was preferred by call back */
              if (pref_cipher == NULL)
                  pref_cipher = ssl3_choose_cipher(s, s->peer_ciphers,
                                                   SSL_get_ciphers(s));
              if (pref_cipher == NULL) {
                  SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                           SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                           SSL_R_NO_SHARED_CIPHER);
                  goto err;
              }
  
              s->session->cipher = pref_cipher;
              sk_SSL_CIPHER_free(s->cipher_list);
              s->cipher_list = sk_SSL_CIPHER_dup(s->peer_ciphers);
              sk_SSL_CIPHER_free(s->cipher_list_by_id);
              s->cipher_list_by_id = sk_SSL_CIPHER_dup(s->peer_ciphers);
          }
      }
  
      /*
       * Worst case, we will use the NULL compression, but if we have other
       * options, we will now look for them.  We have complen-1 compression
       * algorithms from the client, starting at q.
       */
      s->s3.tmp.new_compression = NULL;
      if (SSL_IS_TLS13(s)) {
          /*
           * We already checked above that the NULL compression method appears in
           * the list. Now we check there aren't any others (which is illegal in
           * a TLSv1.3 ClientHello.
           */
          if (clienthello->compressions_len != 1) {
              SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       SSL_R_INVALID_COMPRESSION_ALGORITHM);
              goto err;
          }
      }
  #ifndef OPENSSL_NO_COMP
      /* This only happens if we have a cache hit */
      else if (s->session->compress_meth != 0) {
          int m, comp_id = s->session->compress_meth;
          unsigned int k;
          /* Perform sanity checks on resumed compression algorithm */
          /* Can't disable compression */
          if (!ssl_allow_compression(s)) {
              SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       SSL_R_INCONSISTENT_COMPRESSION);
              goto err;
          }
          /* Look for resumed compression method */
          for (m = 0; m < sk_SSL_COMP_num(s->ctx->comp_methods); m++) {
              comp = sk_SSL_COMP_value(s->ctx->comp_methods, m);
              if (comp_id == comp->id) {
                  s->s3.tmp.new_compression = comp;
                  break;
              }
          }
          if (s->s3.tmp.new_compression == NULL) {
              SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       SSL_R_INVALID_COMPRESSION_ALGORITHM);
              goto err;
          }
          /* Look for resumed method in compression list */
          for (k = 0; k < clienthello->compressions_len; k++) {
              if (clienthello->compressions[k] == comp_id)
                  break;
          }
          if (k >= clienthello->compressions_len) {
              SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       SSL_R_REQUIRED_COMPRESSION_ALGORITHM_MISSING);
              goto err;
          }
      } else if (s->hit) {
          comp = NULL;
      } else if (ssl_allow_compression(s) && s->ctx->comp_methods) {
          /* See if we have a match */
          int m, nn, v, done = 0;
          unsigned int o;
  
          nn = sk_SSL_COMP_num(s->ctx->comp_methods);
          for (m = 0; m < nn; m++) {
              comp = sk_SSL_COMP_value(s->ctx->comp_methods, m);
              v = comp->id;
              for (o = 0; o < clienthello->compressions_len; o++) {
                  if (v == clienthello->compressions[o]) {
                      done = 1;
                      break;
                  }
              }
              if (done)
                  break;
          }
          if (done)
              s->s3.tmp.new_compression = comp;
          else
              comp = NULL;
      }
  #else
      /*
       * 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_EARLY_POST_PROCESS_CLIENT_HELLO,
                   SSL_R_INCONSISTENT_COMPRESSION);
          goto err;
      }
  #endif
  
      /*
       * Given s->peer_ciphers and SSL_get_ciphers, we must pick a cipher
       */
  
      if (!s->hit || SSL_IS_TLS13(s)) {
          sk_SSL_CIPHER_free(s->peer_ciphers);
          s->peer_ciphers = ciphers;
          if (ciphers == NULL) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
          ciphers = NULL;
      }
  
      if (!s->hit) {
  #ifdef OPENSSL_NO_COMP
          s->session->compress_meth = 0;
  #else
          s->session->compress_meth = (comp == NULL) ? 0 : comp->id;
  #endif
          if (!tls1_set_server_sigalgs(s)) {
              /* SSLfatal() already called */
              goto err;
          }
      }
  
      sk_SSL_CIPHER_free(ciphers);
      sk_SSL_CIPHER_free(scsvs);
      OPENSSL_free(clienthello->pre_proc_exts);
      OPENSSL_free(s->clienthello);
      s->clienthello = NULL;
      return 1;
   err:
      sk_SSL_CIPHER_free(ciphers);
      sk_SSL_CIPHER_free(scsvs);
      OPENSSL_free(clienthello->pre_proc_exts);
      OPENSSL_free(s->clienthello);
      s->clienthello = NULL;
  
      return 0;
  }
  
  /*
   * Call the status request callback if needed. Upon success, returns 1.
   * Upon failure, returns 0.
   */
  static int tls_handle_status_request(SSL *s)
  {
      s->ext.status_expected = 0;
  
      /*
       * If status request then ask callback what to do. Note: this must be
       * called after servername callbacks in case the certificate has changed,
       * and must be called after the cipher has been chosen because this may
       * influence which certificate is sent
       */
      if (s->ext.status_type != TLSEXT_STATUSTYPE_nothing && s->ctx != NULL
              && s->ctx->ext.status_cb != NULL) {
          int ret;
  
          /* If no certificate can't return certificate status */
          if (s->s3.tmp.cert != NULL) {
              /*
               * Set current certificate to one we will use so SSL_get_certificate
               * et al can pick it up.
               */
              s->cert->key = s->s3.tmp.cert;
              ret = s->ctx->ext.status_cb(s, s->ctx->ext.status_arg);
              switch (ret) {
                  /* We don't want to send a status request response */
              case SSL_TLSEXT_ERR_NOACK:
                  s->ext.status_expected = 0;
                  break;
                  /* status request response should be sent */
              case SSL_TLSEXT_ERR_OK:
                  if (s->ext.ocsp.resp)
                      s->ext.status_expected = 1;
                  break;
                  /* something bad happened */
              case SSL_TLSEXT_ERR_ALERT_FATAL:
              default:
                  SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                           SSL_F_TLS_HANDLE_STATUS_REQUEST,
                           SSL_R_CLIENTHELLO_TLSEXT);
                  return 0;
              }
          }
      }
  
      return 1;
  }
  
  /*
   * Call the alpn_select callback if needed. Upon success, returns 1.
   * Upon failure, returns 0.
   */
  int tls_handle_alpn(SSL *s)
  {
      const unsigned char *selected = NULL;
      unsigned char selected_len = 0;
  
      if (s->ctx->ext.alpn_select_cb != NULL && s->s3.alpn_proposed != NULL) {
          int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len,
                                             s->s3.alpn_proposed,
                                             (unsigned int)s->s3.alpn_proposed_len,
                                             s->ctx->ext.alpn_select_cb_arg);
  
          if (r == SSL_TLSEXT_ERR_OK) {
              OPENSSL_free(s->s3.alpn_selected);
              s->s3.alpn_selected = OPENSSL_memdup(selected, selected_len);
              if (s->s3.alpn_selected == NULL) {
                  SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_HANDLE_ALPN,
                           ERR_R_INTERNAL_ERROR);
                  return 0;
              }
              s->s3.alpn_selected_len = selected_len;
  #ifndef OPENSSL_NO_NEXTPROTONEG
              /* ALPN takes precedence over NPN. */
              s->s3.npn_seen = 0;
  #endif
  
              /* Check ALPN is consistent with session */
              if (s->session->ext.alpn_selected == NULL
                          || selected_len != s->session->ext.alpn_selected_len
                          || memcmp(selected, s->session->ext.alpn_selected,
                                    selected_len) != 0) {
                  /* Not consistent so can't be used for early_data */
                  s->ext.early_data_ok = 0;
  
                  if (!s->hit) {
                      /*
                       * This is a new session and so alpn_selected should have
                       * been initialised to NULL. We should update it with the
                       * selected ALPN.
                       */
                      if (!ossl_assert(s->session->ext.alpn_selected == NULL)) {
                          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                                   SSL_F_TLS_HANDLE_ALPN,
                                   ERR_R_INTERNAL_ERROR);
                          return 0;
                      }
                      s->session->ext.alpn_selected = OPENSSL_memdup(selected,
                                                                     selected_len);
                      if (s->session->ext.alpn_selected == NULL) {
                          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                                   SSL_F_TLS_HANDLE_ALPN,
                                   ERR_R_INTERNAL_ERROR);
                          return 0;
                      }
                      s->session->ext.alpn_selected_len = selected_len;
                  }
              }
  
              return 1;
          } else if (r != SSL_TLSEXT_ERR_NOACK) {
              SSLfatal(s, SSL_AD_NO_APPLICATION_PROTOCOL, SSL_F_TLS_HANDLE_ALPN,
                       SSL_R_NO_APPLICATION_PROTOCOL);
              return 0;
          }
          /*
           * If r == SSL_TLSEXT_ERR_NOACK then behave as if no callback was
           * present.
           */
      }
  
      /* Check ALPN is consistent with session */
      if (s->session->ext.alpn_selected != NULL) {
          /* Not consistent so can't be used for early_data */
          s->ext.early_data_ok = 0;
      }
  
      return 1;
  }
  
  WORK_STATE tls_post_process_client_hello(SSL *s, WORK_STATE wst)
  {
      const SSL_CIPHER *cipher;
  
      if (wst == WORK_MORE_A) {
          int rv = tls_early_post_process_client_hello(s);
          if (rv == 0) {
              /* SSLfatal() was already called */
              goto err;
          }
          if (rv < 0)
              return WORK_MORE_A;
          wst = WORK_MORE_B;
      }
      if (wst == WORK_MORE_B) {
          if (!s->hit || SSL_IS_TLS13(s)) {
              /* Let cert callback update server certificates if required */
              if (!s->hit && s->cert->cert_cb != NULL) {
                  int rv = s->cert->cert_cb(s, s->cert->cert_cb_arg);
                  if (rv == 0) {
                      SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                               SSL_F_TLS_POST_PROCESS_CLIENT_HELLO,
                               SSL_R_CERT_CB_ERROR);
                      goto err;
                  }
                  if (rv < 0) {
                      s->rwstate = SSL_X509_LOOKUP;
                      return WORK_MORE_B;
                  }
                  s->rwstate = SSL_NOTHING;
              }
  
              /* In TLSv1.3 we selected the ciphersuite before resumption */
              if (!SSL_IS_TLS13(s)) {
                  cipher =
                      ssl3_choose_cipher(s, s->peer_ciphers, SSL_get_ciphers(s));
  
                  if (cipher == NULL) {
                      SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                               SSL_F_TLS_POST_PROCESS_CLIENT_HELLO,
                               SSL_R_NO_SHARED_CIPHER);
                      goto err;
                  }
                  s->s3.tmp.new_cipher = cipher;
              }
              if (!s->hit) {
                  if (!tls_choose_sigalg(s, 1)) {
                      /* SSLfatal already called */
                      goto err;
                  }
                  /* check whether we should disable session resumption */
                  if (s->not_resumable_session_cb != NULL)
                      s->session->not_resumable =
                          s->not_resumable_session_cb(s,
                              ((s->s3.tmp.new_cipher->algorithm_mkey
                                & (SSL_kDHE | SSL_kECDHE)) != 0));
                  if (s->session->not_resumable)
                      /* do not send a session ticket */
                      s->ext.ticket_expected = 0;
              }
          } else {
              /* Session-id reuse */
              s->s3.tmp.new_cipher = s->session->cipher;
          }
  
          /*-
           * we now have the following setup.
           * client_random
           * cipher_list          - our preferred list of ciphers
           * ciphers              - the clients preferred list of ciphers
           * compression          - basically ignored right now
           * ssl version is set   - sslv3
           * s->session           - The ssl session has been setup.
           * s->hit               - session reuse flag
           * s->s3.tmp.new_cipher - the new cipher to use.
           */
  
          /*
           * Call status_request callback if needed. Has to be done after the
           * certificate callbacks etc above.
           */
          if (!tls_handle_status_request(s)) {
              /* SSLfatal() already called */
              goto err;
          }
          /*
           * Call alpn_select callback if needed.  Has to be done after SNI and
           * cipher negotiation (HTTP/2 restricts permitted ciphers). In TLSv1.3
           * we already did this because cipher negotiation happens earlier, and
           * we must handle ALPN before we decide whether to accept early_data.
           */
          if (!SSL_IS_TLS13(s) && !tls_handle_alpn(s)) {
              /* SSLfatal() already called */
              goto err;
          }
  
          wst = WORK_MORE_C;
      }
  #ifndef OPENSSL_NO_SRP
      if (wst == WORK_MORE_C) {
          int ret;
          if ((ret = ssl_check_srp_ext_ClientHello(s)) == 0) {
              /*
               * callback indicates further work to be done
               */
              s->rwstate = SSL_X509_LOOKUP;
              return WORK_MORE_C;
          }
          if (ret < 0) {
              /* SSLfatal() already called */
              goto err;
          }
      }
  #endif
  
      return WORK_FINISHED_STOP;
   err:
      return WORK_ERROR;
  }
  
  int tls_construct_server_hello(SSL *s, WPACKET *pkt)
  {
      int compm;
      size_t sl, len;
      int version;
      unsigned char *session_id;
      int usetls13 = SSL_IS_TLS13(s) || s->hello_retry_request == SSL_HRR_PENDING;
  
      version = usetls13 ? TLS1_2_VERSION : s->version;
      if (!WPACKET_put_bytes_u16(pkt, version)
                 /*
                  * Random stuff. Filling of the server_random takes place in
                  * tls_process_client_hello()
                  */
              || !WPACKET_memcpy(pkt,
                                 s->hello_retry_request == SSL_HRR_PENDING
                                     ? hrrrandom : s->s3.server_random,
                                 SSL3_RANDOM_SIZE)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_SERVER_HELLO,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      /*-
       * There are several cases for the session ID to send
       * back in the server hello:
       * - For session reuse from the session cache,
       *   we send back the old session ID.
       * - If stateless session reuse (using a session ticket)
       *   is successful, we send back the client's "session ID"
       *   (which doesn't actually identify the session).
       * - If it is a new session, we send back the new
       *   session ID.
       * - However, if we want the new session to be single-use,
       *   we send back a 0-length session ID.
       * - In TLSv1.3 we echo back the session id sent to us by the client
       *   regardless
       * s->hit is non-zero in either case of session reuse,
       * so the following won't overwrite an ID that we're supposed
       * to send back.
       */
      if (s->session->not_resumable ||
          (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)
           && !s->hit))
          s->session->session_id_length = 0;
  
      if (usetls13) {
          sl = s->tmp_session_id_len;
          session_id = s->tmp_session_id;
      } else {
          sl = s->session->session_id_length;
          session_id = s->session->session_id;
      }
  
      if (sl > sizeof(s->session->session_id)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_SERVER_HELLO,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      /* set up the compression method */
  #ifdef OPENSSL_NO_COMP
      compm = 0;
  #else
      if (usetls13 || s->s3.tmp.new_compression == NULL)
          compm = 0;
      else
          compm = s->s3.tmp.new_compression->id;
  #endif
  
      if (!WPACKET_sub_memcpy_u8(pkt, session_id, sl)
              || !s->method->put_cipher_by_char(s->s3.tmp.new_cipher, pkt, &len)
              || !WPACKET_put_bytes_u8(pkt, compm)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_SERVER_HELLO,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      if (!tls_construct_extensions(s, pkt,
                                    s->hello_retry_request == SSL_HRR_PENDING
                                        ? SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
                                        : (SSL_IS_TLS13(s)
                                            ? SSL_EXT_TLS1_3_SERVER_HELLO
                                            : SSL_EXT_TLS1_2_SERVER_HELLO),
                                    NULL, 0)) {
          /* SSLfatal() already called */
          return 0;
      }
  
      if (s->hello_retry_request == SSL_HRR_PENDING) {
          /* Ditch the session. We'll create a new one next time around */
          SSL_SESSION_free(s->session);
          s->session = NULL;
          s->hit = 0;
  
          /*
           * 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 */
              return 0;
          }
      } else if (!(s->verify_mode & SSL_VERIFY_PEER)
                  && !ssl3_digest_cached_records(s, 0)) {
          /* SSLfatal() already called */;
          return 0;
      }
  
      return 1;
  }
  
  int tls_construct_server_done(SSL *s, WPACKET *pkt)
  {
      if (!s->s3.tmp.cert_request) {
          if (!ssl3_digest_cached_records(s, 0)) {
              /* SSLfatal() already called */
              return 0;
          }
      }
      return 1;
  }
  
  int tls_construct_server_key_exchange(SSL *s, WPACKET *pkt)
  {
  #ifndef OPENSSL_NO_DH
      EVP_PKEY *pkdh = NULL;
  #endif
  #ifndef OPENSSL_NO_EC
      unsigned char *encodedPoint = NULL;
      size_t encodedlen = 0;
      int curve_id = 0;
  #endif
      const SIGALG_LOOKUP *lu = s->s3.tmp.sigalg;
      int i;
      unsigned long type;
      const BIGNUM *r[4];
      EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
      EVP_PKEY_CTX *pctx = NULL;
      size_t paramlen, paramoffset;
  
      if (!WPACKET_get_total_written(pkt, &paramoffset)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
          goto err;
      }
  
      if (md_ctx == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      type = s->s3.tmp.new_cipher->algorithm_mkey;
  
      r[0] = r[1] = r[2] = r[3] = NULL;
  #ifndef OPENSSL_NO_PSK
      /* Plain PSK or RSAPSK nothing to do */
      if (type & (SSL_kPSK | SSL_kRSAPSK)) {
      } else
  #endif                          /* !OPENSSL_NO_PSK */
  #ifndef OPENSSL_NO_DH
      if (type & (SSL_kDHE | SSL_kDHEPSK)) {
          CERT *cert = s->cert;
  
          EVP_PKEY *pkdhp = NULL;
          DH *dh;
  
          if (s->cert->dh_tmp_auto) {
              DH *dhp = ssl_get_auto_dh(s);
              pkdh = EVP_PKEY_new();
              if (pkdh == NULL || dhp == NULL) {
                  DH_free(dhp);
                  SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                           SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                           ERR_R_INTERNAL_ERROR);
                  goto err;
              }
              EVP_PKEY_assign_DH(pkdh, dhp);
              pkdhp = pkdh;
          } else {
              pkdhp = cert->dh_tmp;
          }
          if ((pkdhp == NULL) && (s->cert->dh_tmp_cb != NULL)) {
              DH *dhp = s->cert->dh_tmp_cb(s, 0, 1024);
              pkdh = ssl_dh_to_pkey(dhp);
              if (pkdh == NULL) {
                  SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                           SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                           ERR_R_INTERNAL_ERROR);
                  goto err;
              }
              pkdhp = pkdh;
          }
          if (pkdhp == NULL) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       SSL_R_MISSING_TMP_DH_KEY);
              goto err;
          }
          if (!ssl_security(s, SSL_SECOP_TMP_DH,
                            EVP_PKEY_security_bits(pkdhp), 0, pkdhp)) {
              SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       SSL_R_DH_KEY_TOO_SMALL);
              goto err;
          }
          if (s->s3.tmp.pkey != NULL) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
  
          s->s3.tmp.pkey = ssl_generate_pkey(s, pkdhp);
          if (s->s3.tmp.pkey == NULL) {
              /* SSLfatal() already called */
              goto err;
          }
  
          dh = EVP_PKEY_get0_DH(s->s3.tmp.pkey);
          if (dh == NULL) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
  
          EVP_PKEY_free(pkdh);
          pkdh = NULL;
  
          DH_get0_pqg(dh, &r[0], NULL, &r[1]);
          DH_get0_key(dh, &r[2], NULL);
      } else
  #endif
  #ifndef OPENSSL_NO_EC
      if (type & (SSL_kECDHE | SSL_kECDHEPSK)) {
  
          if (s->s3.tmp.pkey != NULL) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
  
          /* Get NID of appropriate shared curve */
          curve_id = tls1_shared_group(s, -2);
          if (curve_id == 0) {
              SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       SSL_R_UNSUPPORTED_ELLIPTIC_CURVE);
              goto err;
          }
          s->s3.tmp.pkey = ssl_generate_pkey_group(s, curve_id);
          /* Generate a new key for this curve */
          if (s->s3.tmp.pkey == NULL) {
              /* SSLfatal() already called */
              goto err;
          }
  
          /*
           * TODO(3.0) Remove this when EVP_PKEY_get1_tls_encodedpoint()
           * knows how to get a key from an encoded point with the help of
           * a OSSL_SERIALIZER deserializer.  We know that EVP_PKEY_get0()
           * downgrades an EVP_PKEY to contain a legacy key.
           *
           * THIS IS TEMPORARY
           */
          EVP_PKEY_get0(s->s3.tmp.pkey);
          if (EVP_PKEY_id(s->s3.tmp.pkey) == EVP_PKEY_NONE) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, 0, ERR_R_EC_LIB);
              goto err;
          }
  
          /* Encode the public key. */
          encodedlen = EVP_PKEY_get1_tls_encodedpoint(s->s3.tmp.pkey,
                                                      &encodedPoint);
          if (encodedlen == 0) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE, ERR_R_EC_LIB);
              goto err;
          }
  
          /*
           * We'll generate the serverKeyExchange message explicitly so we
           * can set these to NULLs
           */
          r[0] = NULL;
          r[1] = NULL;
          r[2] = NULL;
          r[3] = NULL;
      } else
  #endif                          /* !OPENSSL_NO_EC */
  #ifndef OPENSSL_NO_SRP
      if (type & SSL_kSRP) {
          if ((s->srp_ctx.N == NULL) ||
              (s->srp_ctx.g == NULL) ||
              (s->srp_ctx.s == NULL) || (s->srp_ctx.B == NULL)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       SSL_R_MISSING_SRP_PARAM);
              goto err;
          }
          r[0] = s->srp_ctx.N;
          r[1] = s->srp_ctx.g;
          r[2] = s->srp_ctx.s;
          r[3] = s->srp_ctx.B;
      } else
  #endif
      {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                   SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
          goto err;
      }
  
      if (((s->s3.tmp.new_cipher->algorithm_auth & (SSL_aNULL | SSL_aSRP)) != 0)
          || ((s->s3.tmp.new_cipher->algorithm_mkey & SSL_PSK)) != 0) {
          lu = NULL;
      } else if (lu == NULL) {
          SSLfatal(s, SSL_AD_DECODE_ERROR,
                   SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
          goto err;
      }
  
  #ifndef OPENSSL_NO_PSK
      if (type & SSL_PSK) {
          size_t len = (s->cert->psk_identity_hint == NULL)
                          ? 0 : strlen(s->cert->psk_identity_hint);
  
          /*
           * It should not happen that len > PSK_MAX_IDENTITY_LEN - we already
           * checked this when we set the identity hint - but just in case
           */
          if (len > PSK_MAX_IDENTITY_LEN
                  || !WPACKET_sub_memcpy_u16(pkt, s->cert->psk_identity_hint,
                                             len)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
      }
  #endif
  
      for (i = 0; i < 4 && r[i] != NULL; i++) {
          unsigned char *binval;
          int res;
  
  #ifndef OPENSSL_NO_SRP
          if ((i == 2) && (type & SSL_kSRP)) {
              res = WPACKET_start_sub_packet_u8(pkt);
          } else
  #endif
              res = WPACKET_start_sub_packet_u16(pkt);
  
          if (!res) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
  
  #ifndef OPENSSL_NO_DH
          /*-
           * for interoperability with some versions of the Microsoft TLS
           * stack, we need to zero pad the DHE pub key to the same length
           * as the prime
           */
          if ((i == 2) && (type & (SSL_kDHE | SSL_kDHEPSK))) {
              size_t len = BN_num_bytes(r[0]) - BN_num_bytes(r[2]);
  
              if (len > 0) {
                  if (!WPACKET_allocate_bytes(pkt, len, &binval)) {
                      SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                               SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                               ERR_R_INTERNAL_ERROR);
                      goto err;
                  }
                  memset(binval, 0, len);
              }
          }
  #endif
          if (!WPACKET_allocate_bytes(pkt, BN_num_bytes(r[i]), &binval)
                  || !WPACKET_close(pkt)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
  
          BN_bn2bin(r[i], binval);
      }
  
  #ifndef OPENSSL_NO_EC
      if (type & (SSL_kECDHE | SSL_kECDHEPSK)) {
          /*
           * We only support named (not generic) curves. In this situation, the
           * ServerKeyExchange message has: [1 byte CurveType], [2 byte CurveName]
           * [1 byte length of encoded point], followed by the actual encoded
           * point itself
           */
          if (!WPACKET_put_bytes_u8(pkt, NAMED_CURVE_TYPE)
                  || !WPACKET_put_bytes_u8(pkt, 0)
                  || !WPACKET_put_bytes_u8(pkt, curve_id)
                  || !WPACKET_sub_memcpy_u8(pkt, encodedPoint, encodedlen)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
          OPENSSL_free(encodedPoint);
          encodedPoint = NULL;
      }
  #endif
  
      /* not anonymous */
      if (lu != NULL) {
          EVP_PKEY *pkey = s->s3.tmp.cert->privatekey;
          const EVP_MD *md;
          unsigned char *sigbytes1, *sigbytes2, *tbs;
          size_t siglen = 0, tbslen;
  
          if (pkey == NULL || !tls1_lookup_md(s->ctx, lu, &md)) {
              /* Should never happen */
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
          /* Get length of the parameters we have written above */
          if (!WPACKET_get_length(pkt, &paramlen)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
          /* send signature algorithm */
          if (SSL_USE_SIGALGS(s) && !WPACKET_put_bytes_u16(pkt, lu->sigalg)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
  
          if (EVP_DigestSignInit_ex(md_ctx, &pctx,
                                    md == NULL ? NULL : EVP_MD_name(md),
                                    s->ctx->propq, pkey, s->ctx->libctx) <= 0) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              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_SERVER_KEY_EXCHANGE,
                          ERR_R_EVP_LIB);
                  goto err;
              }
          }
          tbslen = construct_key_exchange_tbs(s, &tbs,
                                              s->init_buf->data + paramoffset,
                                              paramlen);
          if (tbslen == 0) {
              /* SSLfatal() already called */
              goto err;
          }
  
          if (EVP_DigestSign(md_ctx, NULL, &siglen, tbs, tbslen) <=0
                  || !WPACKET_sub_reserve_bytes_u16(pkt, siglen, &sigbytes1)
                  || EVP_DigestSign(md_ctx, sigbytes1, &siglen, tbs, tbslen) <= 0
                  || !WPACKET_sub_allocate_bytes_u16(pkt, siglen, &sigbytes2)
                  || sigbytes1 != sigbytes2) {
              OPENSSL_free(tbs);
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
          OPENSSL_free(tbs);
      }
  
      EVP_MD_CTX_free(md_ctx);
      return 1;
   err:
  #ifndef OPENSSL_NO_DH
      EVP_PKEY_free(pkdh);
  #endif
  #ifndef OPENSSL_NO_EC
      OPENSSL_free(encodedPoint);
  #endif
      EVP_MD_CTX_free(md_ctx);
      return 0;
  }
  
  int tls_construct_certificate_request(SSL *s, WPACKET *pkt)
  {
      if (SSL_IS_TLS13(s)) {
          /* Send random context when doing post-handshake auth */
          if (s->post_handshake_auth == SSL_PHA_REQUEST_PENDING) {
              OPENSSL_free(s->pha_context);
              s->pha_context_len = 32;
              if ((s->pha_context = OPENSSL_malloc(s->pha_context_len)) == NULL
                      || RAND_bytes_ex(s->ctx->libctx, s->pha_context,
                                       s->pha_context_len) <= 0
                      || !WPACKET_sub_memcpy_u8(pkt, s->pha_context, s->pha_context_len)) {
                  SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                           SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST,
                           ERR_R_INTERNAL_ERROR);
                  return 0;
              }
              /* reset the handshake hash back to just after the ClientFinished */
              if (!tls13_restore_handshake_digest_for_pha(s)) {
                  /* SSLfatal() already called */
                  return 0;
              }
          } else {
              if (!WPACKET_put_bytes_u8(pkt, 0)) {
                  SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                           SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST,
                           ERR_R_INTERNAL_ERROR);
                  return 0;
              }
          }
  
          if (!tls_construct_extensions(s, pkt,
                                        SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, NULL,
                                        0)) {
              /* SSLfatal() already called */
              return 0;
          }
          goto done;
      }
  
      /* get the list of acceptable cert types */
      if (!WPACKET_start_sub_packet_u8(pkt)
          || !ssl3_get_req_cert_type(s, pkt) || !WPACKET_close(pkt)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST, ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      if (SSL_USE_SIGALGS(s)) {
          const uint16_t *psigs;
          size_t nl = tls12_get_psigalgs(s, 1, &psigs);
  
          if (!WPACKET_start_sub_packet_u16(pkt)
                  || !WPACKET_set_flags(pkt, WPACKET_FLAGS_NON_ZERO_LENGTH)
                  || !tls12_copy_sigalgs(s, pkt, psigs, nl)
                  || !WPACKET_close(pkt)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_CERTIFICATE_REQUEST,
                       ERR_R_INTERNAL_ERROR);
              return 0;
          }
      }
  
      if (!construct_ca_names(s, get_ca_names(s), pkt)) {
          /* SSLfatal() already called */
          return 0;
      }
  
   done:
      s->certreqs_sent++;
      s->s3.tmp.cert_request = 1;
      return 1;
  }
  
  static int tls_process_cke_psk_preamble(SSL *s, PACKET *pkt)
  {
  #ifndef OPENSSL_NO_PSK
      unsigned char psk[PSK_MAX_PSK_LEN];
      size_t psklen;
      PACKET psk_identity;
  
      if (!PACKET_get_length_prefixed_2(pkt, &psk_identity)) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CKE_PSK_PREAMBLE,
                   SSL_R_LENGTH_MISMATCH);
          return 0;
      }
      if (PACKET_remaining(&psk_identity) > PSK_MAX_IDENTITY_LEN) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CKE_PSK_PREAMBLE,
                   SSL_R_DATA_LENGTH_TOO_LONG);
          return 0;
      }
      if (s->psk_server_callback == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_PSK_PREAMBLE,
                   SSL_R_PSK_NO_SERVER_CB);
          return 0;
      }
  
      if (!PACKET_strndup(&psk_identity, &s->session->psk_identity)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_PSK_PREAMBLE,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      psklen = s->psk_server_callback(s, s->session->psk_identity,
                                      psk, sizeof(psk));
  
      if (psklen > PSK_MAX_PSK_LEN) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_PSK_PREAMBLE,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      } else if (psklen == 0) {
          /*
           * PSK related to the given identity not found
           */
          SSLfatal(s, SSL_AD_UNKNOWN_PSK_IDENTITY,
                   SSL_F_TLS_PROCESS_CKE_PSK_PREAMBLE,
                   SSL_R_PSK_IDENTITY_NOT_FOUND);
          return 0;
      }
  
      OPENSSL_free(s->s3.tmp.psk);
      s->s3.tmp.psk = OPENSSL_memdup(psk, psklen);
      OPENSSL_cleanse(psk, psklen);
  
      if (s->s3.tmp.psk == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_TLS_PROCESS_CKE_PSK_PREAMBLE, ERR_R_MALLOC_FAILURE);
          return 0;
      }
  
      s->s3.tmp.psklen = psklen;
  
      return 1;
  #else
      /* Should never happen */
      SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_PSK_PREAMBLE,
               ERR_R_INTERNAL_ERROR);
      return 0;
  #endif
  }
  
  static int tls_process_cke_rsa(SSL *s, PACKET *pkt)
  {
  #ifndef OPENSSL_NO_RSA
      size_t outlen;
      PACKET enc_premaster;
      EVP_PKEY *rsa = NULL;
      unsigned char *rsa_decrypt = NULL;
      int ret = 0;
      EVP_PKEY_CTX *ctx = NULL;
      OSSL_PARAM params[3], *p = params;
  
      rsa = s->cert->pkeys[SSL_PKEY_RSA].privatekey;
      if (rsa == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_RSA,
                   SSL_R_MISSING_RSA_CERTIFICATE);
          return 0;
      }
  
      /* SSLv3 and pre-standard DTLS omit the length bytes. */
      if (s->version == SSL3_VERSION || s->version == DTLS1_BAD_VER) {
          enc_premaster = *pkt;
      } else {
          if (!PACKET_get_length_prefixed_2(pkt, &enc_premaster)
              || PACKET_remaining(pkt) != 0) {
              SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CKE_RSA,
                       SSL_R_LENGTH_MISMATCH);
              return 0;
          }
      }
  
      outlen = SSL_MAX_MASTER_KEY_LENGTH;
      rsa_decrypt = OPENSSL_malloc(outlen);
      if (rsa_decrypt == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_RSA,
                   ERR_R_MALLOC_FAILURE);
          return 0;
      }
  
      ctx = EVP_PKEY_CTX_new_from_pkey(s->ctx->libctx, rsa, s->ctx->propq);
      if (ctx == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_RSA,
                   ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      /*
       * We must not leak whether a decryption failure occurs because of
       * Bleichenbacher's attack on PKCS #1 v1.5 RSA padding (see RFC 2246,
       * section 7.4.7.1). We use the special padding type
       * RSA_PKCS1_WITH_TLS_PADDING to do that. It will automaticaly decrypt the
       * RSA, check the padding and check that the client version is as expected
       * in the premaster secret. If any of that fails then the function appears
       * to return successfully but with a random result. The call below could
       * still fail if the input is publicly invalid.
       * See https://tools.ietf.org/html/rfc5246#section-7.4.7.1
       */
      if (EVP_PKEY_decrypt_init(ctx) <= 0
              || EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_WITH_TLS_PADDING) <= 0) {
          SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_CKE_RSA,
                   SSL_R_DECRYPTION_FAILED);
          goto err;
      }
  
      *p++ = OSSL_PARAM_construct_uint(OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION,
                                       (unsigned int *)&s->client_version);
     if ((s->options & SSL_OP_TLS_ROLLBACK_BUG) != 0)
          *p++ = OSSL_PARAM_construct_uint(
              OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION,
              (unsigned int *)&s->version);
      *p++ = OSSL_PARAM_construct_end();
  
      if (!EVP_PKEY_CTX_set_params(ctx, params)
              || EVP_PKEY_decrypt(ctx, rsa_decrypt, &outlen,
                                  PACKET_data(&enc_premaster),
                                  PACKET_remaining(&enc_premaster)) <= 0) {
          SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_CKE_RSA,
                   SSL_R_DECRYPTION_FAILED);
          goto err;
      }
  
      /*
       * This test should never fail (otherwise we should have failed above) but
       * we double check anyway.
       */
      if (outlen != SSL_MAX_MASTER_KEY_LENGTH) {
          OPENSSL_cleanse(rsa_decrypt, SSL_MAX_MASTER_KEY_LENGTH);
          SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_CKE_RSA,
                   SSL_R_DECRYPTION_FAILED);
          goto err;
      }
  
      /* Also cleanses rsa_decrypt (on success or failure) */
      if (!ssl_generate_master_secret(s, rsa_decrypt,
                                      SSL_MAX_MASTER_KEY_LENGTH, 0)) {
          /* SSLfatal() already called */
          goto err;
      }
  
      ret = 1;
   err:
      OPENSSL_free(rsa_decrypt);
      EVP_PKEY_CTX_free(ctx);
      return ret;
  #else
      /* Should never happen */
      SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_RSA,
               ERR_R_INTERNAL_ERROR);
      return 0;
  #endif
  }
  
  static int tls_process_cke_dhe(SSL *s, PACKET *pkt)
  {
  #ifndef OPENSSL_NO_DH
      EVP_PKEY *skey = NULL;
      DH *cdh;
      unsigned int i;
      BIGNUM *pub_key;
      const unsigned char *data;
      EVP_PKEY *ckey = NULL;
      int ret = 0;
  
      if (!PACKET_get_net_2(pkt, &i) || PACKET_remaining(pkt) != i) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CKE_DHE,
                 SSL_R_DH_PUBLIC_VALUE_LENGTH_IS_WRONG);
          goto err;
      }
      skey = s->s3.tmp.pkey;
      if (skey == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_DHE,
                   SSL_R_MISSING_TMP_DH_KEY);
          goto err;
      }
  
      if (PACKET_remaining(pkt) == 0L) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CKE_DHE,
                   SSL_R_MISSING_TMP_DH_KEY);
          goto err;
      }
      if (!PACKET_get_bytes(pkt, &data, i)) {
          /* We already checked we have enough data */
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_DHE,
                   ERR_R_INTERNAL_ERROR);
          goto err;
      }
      ckey = EVP_PKEY_new();
      if (ckey == NULL || EVP_PKEY_copy_parameters(ckey, skey) == 0) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_DHE,
                   SSL_R_BN_LIB);
          goto err;
      }
  
      cdh = EVP_PKEY_get0_DH(ckey);
      pub_key = BN_bin2bn(data, i, NULL);
      if (pub_key == NULL || cdh == NULL || !DH_set0_key(cdh, pub_key, NULL)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_DHE,
                   ERR_R_INTERNAL_ERROR);
          BN_free(pub_key);
          goto err;
      }
  
      if (ssl_derive(s, skey, ckey, 1) == 0) {
          /* SSLfatal() already called */
          goto err;
      }
  
      ret = 1;
      EVP_PKEY_free(s->s3.tmp.pkey);
      s->s3.tmp.pkey = NULL;
   err:
      EVP_PKEY_free(ckey);
      return ret;
  #else
      /* Should never happen */
      SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_DHE,
               ERR_R_INTERNAL_ERROR);
      return 0;
  #endif
  }
  
  static int tls_process_cke_ecdhe(SSL *s, PACKET *pkt)
  {
  #ifndef OPENSSL_NO_EC
      EVP_PKEY *skey = s->s3.tmp.pkey;
      EVP_PKEY *ckey = NULL;
      int ret = 0;
  
      if (PACKET_remaining(pkt) == 0L) {
          /* We don't support ECDH client auth */
          SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PROCESS_CKE_ECDHE,
                   SSL_R_MISSING_TMP_ECDH_KEY);
          goto err;
      } else {
          unsigned int i;
          const unsigned char *data;
  
          /*
           * Get client's public key from encoded point in the
           * ClientKeyExchange message.
           */
  
          /* Get encoded point length */
          if (!PACKET_get_1(pkt, &i) || !PACKET_get_bytes(pkt, &data, i)
              || PACKET_remaining(pkt) != 0) {
              SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CKE_ECDHE,
                       SSL_R_LENGTH_MISMATCH);
              goto err;
          }
          if (skey == NULL) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_ECDHE,
                       SSL_R_MISSING_TMP_ECDH_KEY);
              goto err;
          }
  
          ckey = EVP_PKEY_new();
          if (ckey == NULL || EVP_PKEY_copy_parameters(ckey, skey) <= 0) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_ECDHE,
                       ERR_R_EVP_LIB);
              goto err;
          }
  
          /*
           * TODO(3.0) Remove this when EVP_PKEY_get1_tls_encodedpoint()
           * knows how to get a key from an encoded point with the help of
           * a OSSL_SERIALIZER deserializer.  We know that EVP_PKEY_get0()
           * downgrades an EVP_PKEY to contain a legacy key.
           *
           * THIS IS TEMPORARY
           */
          EVP_PKEY_get0(ckey);
          if (EVP_PKEY_id(ckey) == EVP_PKEY_NONE) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_ECDHE,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
  
          if (EVP_PKEY_set1_tls_encodedpoint(ckey, data, i) == 0) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_ECDHE,
                       ERR_R_EC_LIB);
              goto err;
          }
      }
  
      if (ssl_derive(s, skey, ckey, 1) == 0) {
          /* SSLfatal() already called */
          goto err;
      }
  
      ret = 1;
      EVP_PKEY_free(s->s3.tmp.pkey);
      s->s3.tmp.pkey = NULL;
   err:
      EVP_PKEY_free(ckey);
  
      return ret;
  #else
      /* Should never happen */
      SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_ECDHE,
               ERR_R_INTERNAL_ERROR);
      return 0;
  #endif
  }
  
  static int tls_process_cke_srp(SSL *s, PACKET *pkt)
  {
  #ifndef OPENSSL_NO_SRP
      unsigned int i;
      const unsigned char *data;
  
      if (!PACKET_get_net_2(pkt, &i)
          || !PACKET_get_bytes(pkt, &data, i)) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CKE_SRP,
                   SSL_R_BAD_SRP_A_LENGTH);
          return 0;
      }
      if ((s->srp_ctx.A = BN_bin2bn(data, i, NULL)) == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_SRP,
                   ERR_R_BN_LIB);
          return 0;
      }
      if (BN_ucmp(s->srp_ctx.A, s->srp_ctx.N) >= 0 || BN_is_zero(s->srp_ctx.A)) {
          SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_CKE_SRP,
                   SSL_R_BAD_SRP_PARAMETERS);
          return 0;
      }
      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_PROCESS_CKE_SRP,
                   ERR_R_MALLOC_FAILURE);
          return 0;
      }
  
      if (!srp_generate_server_master_secret(s)) {
          /* SSLfatal() already called */
          return 0;
      }
  
      return 1;
  #else
      /* Should never happen */
      SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_SRP,
               ERR_R_INTERNAL_ERROR);
      return 0;
  #endif
  }
  
  static int tls_process_cke_gost(SSL *s, PACKET *pkt)
  {
  #ifndef OPENSSL_NO_GOST
      EVP_PKEY_CTX *pkey_ctx;
      EVP_PKEY *client_pub_pkey = NULL, *pk = NULL;
      unsigned char premaster_secret[32];
      const unsigned char *start;
      size_t outlen = 32, inlen;
      unsigned long alg_a;
      GOST_KX_MESSAGE *pKX = NULL;
      const unsigned char *ptr;
      int ret = 0;
  
      /* Get our certificate private key */
      alg_a = s->s3.tmp.new_cipher->algorithm_auth;
      if (alg_a & SSL_aGOST12) {
          /*
           * New GOST ciphersuites have SSL_aGOST01 bit too
           */
          pk = s->cert->pkeys[SSL_PKEY_GOST12_512].privatekey;
          if (pk == NULL) {
              pk = s->cert->pkeys[SSL_PKEY_GOST12_256].privatekey;
          }
          if (pk == NULL) {
              pk = s->cert->pkeys[SSL_PKEY_GOST01].privatekey;
          }
      } else if (alg_a & SSL_aGOST01) {
          pk = s->cert->pkeys[SSL_PKEY_GOST01].privatekey;
      }
  
      pkey_ctx = EVP_PKEY_CTX_new_from_pkey(s->ctx->libctx, pk, s->ctx->propq);
      if (pkey_ctx == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_GOST,
                   ERR_R_MALLOC_FAILURE);
          return 0;
      }
      if (EVP_PKEY_decrypt_init(pkey_ctx) <= 0) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_GOST,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
      /*
       * If client certificate is present and is of the same type, maybe
       * use it for key exchange.  Don't mind errors from
       * EVP_PKEY_derive_set_peer, because it is completely valid to use a
       * client certificate for authorization only.
       */
      client_pub_pkey = X509_get0_pubkey(s->session->peer);
      if (client_pub_pkey) {
          if (EVP_PKEY_derive_set_peer(pkey_ctx, client_pub_pkey) <= 0)
              ERR_clear_error();
      }
  
      ptr = PACKET_data(pkt);
      /* Some implementations provide extra data in the opaqueBlob
       * We have nothing to do with this blob so we just skip it */
      pKX = d2i_GOST_KX_MESSAGE(NULL, &ptr, PACKET_remaining(pkt));
      if (pKX == NULL
         || pKX->kxBlob == NULL
         || ASN1_TYPE_get(pKX->kxBlob) != V_ASN1_SEQUENCE) {
           SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CKE_GOST,
                    SSL_R_DECRYPTION_FAILED);
           goto err;
      }
  
      if (!PACKET_forward(pkt, ptr - PACKET_data(pkt))) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_GOST,
                   SSL_R_DECRYPTION_FAILED);
          goto err;
      }
  
      if (PACKET_remaining(pkt) != 0) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_GOST,
                   SSL_R_DECRYPTION_FAILED);
          goto err;
      }
  
      inlen = pKX->kxBlob->value.sequence->length;
      start = pKX->kxBlob->value.sequence->data;
  
      if (EVP_PKEY_decrypt(pkey_ctx, premaster_secret, &outlen, start,
                           inlen) <= 0) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CKE_GOST,
                   SSL_R_DECRYPTION_FAILED);
          goto err;
      }
      /* Generate master secret */
      if (!ssl_generate_master_secret(s, premaster_secret,
                                      sizeof(premaster_secret), 0)) {
          /* SSLfatal() already called */
          goto err;
      }
      /* Check if pubkey from client certificate was used */
      if (EVP_PKEY_CTX_ctrl(pkey_ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 2,
                            NULL) > 0)
          s->statem.no_cert_verify = 1;
  
      ret = 1;
   err:
      EVP_PKEY_CTX_free(pkey_ctx);
      GOST_KX_MESSAGE_free(pKX);
      return ret;
  #else
      /* Should never happen */
      SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CKE_GOST,
               ERR_R_INTERNAL_ERROR);
      return 0;
  #endif
  }
  
  MSG_PROCESS_RETURN tls_process_client_key_exchange(SSL *s, PACKET *pkt)
  {
      unsigned long alg_k;
  
      alg_k = s->s3.tmp.new_cipher->algorithm_mkey;
  
      /* For PSK parse and retrieve identity, obtain PSK key */
      if ((alg_k & SSL_PSK) && !tls_process_cke_psk_preamble(s, pkt)) {
          /* SSLfatal() already called */
          goto err;
      }
  
      if (alg_k & SSL_kPSK) {
          /* Identity extracted earlier: should be nothing left */
          if (PACKET_remaining(pkt) != 0) {
              SSLfatal(s, SSL_AD_DECODE_ERROR,
                       SSL_F_TLS_PROCESS_CLIENT_KEY_EXCHANGE,
                       SSL_R_LENGTH_MISMATCH);
              goto err;
          }
          /* PSK handled by ssl_generate_master_secret */
          if (!ssl_generate_master_secret(s, NULL, 0, 0)) {
              /* SSLfatal() already called */
              goto err;
          }
      } else if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {
          if (!tls_process_cke_rsa(s, pkt)) {
              /* SSLfatal() already called */
              goto err;
          }
      } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
          if (!tls_process_cke_dhe(s, pkt)) {
              /* SSLfatal() already called */
              goto err;
          }
      } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
          if (!tls_process_cke_ecdhe(s, pkt)) {
              /* SSLfatal() already called */
              goto err;
          }
      } else if (alg_k & SSL_kSRP) {
          if (!tls_process_cke_srp(s, pkt)) {
              /* SSLfatal() already called */
              goto err;
          }
      } else if (alg_k & SSL_kGOST) {
          if (!tls_process_cke_gost(s, pkt)) {
              /* SSLfatal() already called */
              goto err;
          }
      } else {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_TLS_PROCESS_CLIENT_KEY_EXCHANGE,
                   SSL_R_UNKNOWN_CIPHER_TYPE);
          goto err;
      }
  
      return MSG_PROCESS_CONTINUE_PROCESSING;
   err:
  #ifndef OPENSSL_NO_PSK
      OPENSSL_clear_free(s->s3.tmp.psk, s->s3.tmp.psklen);
      s->s3.tmp.psk = NULL;
  #endif
      return MSG_PROCESS_ERROR;
  }
  
  WORK_STATE tls_post_process_client_key_exchange(SSL *s, WORK_STATE wst)
  {
  #ifndef OPENSSL_NO_SCTP
      if (wst == WORK_MORE_A) {
          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_POST_PROCESS_CLIENT_KEY_EXCHANGE,
                           ERR_R_INTERNAL_ERROR);
                  return WORK_ERROR;
              }
  
              BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
                       sizeof(sctpauthkey), sctpauthkey);
          }
      }
  #endif
  
      if (s->statem.no_cert_verify || !s->session->peer) {
          /*
           * No certificate verify or no peer certificate so we no longer need
           * the handshake_buffer
           */
          if (!ssl3_digest_cached_records(s, 0)) {
              /* SSLfatal() already called */
              return WORK_ERROR;
          }
          return WORK_FINISHED_CONTINUE;
      } else {
          if (!s->s3.handshake_buffer) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_POST_PROCESS_CLIENT_KEY_EXCHANGE,
                       ERR_R_INTERNAL_ERROR);
              return WORK_ERROR;
          }
          /*
           * For sigalgs freeze the handshake buffer. If we support
           * extms we've done this already so this is a no-op
           */
          if (!ssl3_digest_cached_records(s, 1)) {
              /* SSLfatal() already called */
              return WORK_ERROR;
          }
      }
  
      return WORK_FINISHED_CONTINUE;
  }
  
  MSG_PROCESS_RETURN tls_process_client_certificate(SSL *s, PACKET *pkt)
  {
      int i;
      MSG_PROCESS_RETURN ret = MSG_PROCESS_ERROR;
      X509 *x = NULL;
      unsigned long l;
      const unsigned char *certstart, *certbytes;
      STACK_OF(X509) *sk = NULL;
      PACKET spkt, context;
      size_t chainidx;
      SSL_SESSION *new_sess = NULL;
  
      /*
       * 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 ((sk = sk_X509_new_null()) == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                   ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      if (SSL_IS_TLS13(s) && (!PACKET_get_length_prefixed_1(pkt, &context)
                              || (s->pha_context == NULL && PACKET_remaining(&context) != 0)
                              || (s->pha_context != NULL &&
                                  !PACKET_equal(&context, s->pha_context, s->pha_context_len)))) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                   SSL_R_INVALID_CONTEXT);
          goto err;
      }
  
      if (!PACKET_get_length_prefixed_3(pkt, &spkt)
              || PACKET_remaining(pkt) != 0) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                   SSL_R_LENGTH_MISMATCH);
          goto err;
      }
  
      for (chainidx = 0; PACKET_remaining(&spkt) > 0; chainidx++) {
          if (!PACKET_get_net_3(&spkt, &l)
              || !PACKET_get_bytes(&spkt, &certbytes, l)) {
              SSLfatal(s, SSL_AD_DECODE_ERROR,
                       SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                       SSL_R_CERT_LENGTH_MISMATCH);
              goto err;
          }
  
          certstart = certbytes;
          x = d2i_X509(NULL, (const unsigned char **)&certbytes, l);
          if (x == NULL) {
              SSLfatal(s, SSL_AD_DECODE_ERROR,
                       SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE, ERR_R_ASN1_LIB);
              goto err;
          }
          if (certbytes != (certstart + l)) {
              SSLfatal(s, SSL_AD_DECODE_ERROR,
                       SSL_F_TLS_PROCESS_CLIENT_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(&spkt, &extensions)) {
                  SSLfatal(s, SSL_AD_DECODE_ERROR,
                           SSL_F_TLS_PROCESS_CLIENT_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(&spkt) == 0)) {
                  OPENSSL_free(rawexts);
                  goto err;
              }
              OPENSSL_free(rawexts);
          }
  
          if (!sk_X509_push(sk, x)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                       ERR_R_MALLOC_FAILURE);
              goto err;
          }
          x = NULL;
      }
  
      if (sk_X509_num(sk) <= 0) {
          /* TLS does not mind 0 certs returned */
          if (s->version == SSL3_VERSION) {
              SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                       SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                       SSL_R_NO_CERTIFICATES_RETURNED);
              goto err;
          }
          /* Fail for TLS only if we required a certificate */
          else if ((s->verify_mode & SSL_VERIFY_PEER) &&
                   (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
              SSLfatal(s, SSL_AD_CERTIFICATE_REQUIRED,
                       SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                       SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
              goto err;
          }
          /* No client certificate so digest cached records */
          if (s->s3.handshake_buffer && !ssl3_digest_cached_records(s, 0)) {
              /* SSLfatal() already called */
              goto err;
          }
      } else {
          EVP_PKEY *pkey;
          i = ssl_verify_cert_chain(s, sk);
          if (i <= 0) {
              SSLfatal(s, ssl_x509err2alert(s->verify_result),
                       SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                       SSL_R_CERTIFICATE_VERIFY_FAILED);
              goto err;
          }
          if (i > 1) {
              SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                       SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE, i);
              goto err;
          }
          pkey = X509_get0_pubkey(sk_X509_value(sk, 0));
          if (pkey == NULL) {
              SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
                       SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                       SSL_R_UNKNOWN_CERTIFICATE_TYPE);
              goto err;
          }
      }
  
      /*
       * 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. Here, we need to do this every time
       * a new certificate is received via post-handshake authentication, as the
       * session may have already gone into the session cache.
       */
  
      if (s->post_handshake_auth == SSL_PHA_REQUESTED) {
          if ((new_sess = ssl_session_dup(s->session, 0)) == 0) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_PROCESS_CLIENT_CERTIFICATE,
                       ERR_R_MALLOC_FAILURE);
              goto err;
          }
  
          SSL_SESSION_free(s->session);
          s->session = new_sess;
      }
  
      X509_free(s->session->peer);
      s->session->peer = sk_X509_shift(sk);
      s->session->verify_result = s->verify_result;
  
      sk_X509_pop_free(s->session->peer_chain, X509_free);
      s->session->peer_chain = sk;
  
      /*
       * Freeze the handshake buffer. For <TLS1.3 we do this after the CKE
       * message
       */
      if (SSL_IS_TLS13(s) && !ssl3_digest_cached_records(s, 1)) {
          /* SSLfatal() already called */
          goto err;
      }
  
      /*
       * Inconsistency alert: cert_chain does *not* include the peer's own
       * certificate, while we do include it in statem_clnt.c
       */
      sk = NULL;
  
      /* Save the current hash state for when we receive the CertificateVerify */
      if (SSL_IS_TLS13(s)) {
          if (!ssl_handshake_hash(s, s->cert_verify_hash,
                                  sizeof(s->cert_verify_hash),
                                  &s->cert_verify_hash_len)) {
              /* SSLfatal() already called */
              goto err;
          }
  
          /* Resend session tickets */
          s->sent_tickets = 0;
      }
  
      ret = MSG_PROCESS_CONTINUE_READING;
  
   err:
      X509_free(x);
      sk_X509_pop_free(sk, X509_free);
      return ret;
  }
  
  int tls_construct_server_certificate(SSL *s, WPACKET *pkt)
  {
      CERT_PKEY *cpk = s->s3.tmp.cert;
  
      if (cpk == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_TLS_CONSTRUCT_SERVER_CERTIFICATE, ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      /*
       * In TLSv1.3 the certificate chain is always preceded by a 0 length context
       * for the server Certificate message
       */
      if (SSL_IS_TLS13(s) && !WPACKET_put_bytes_u8(pkt, 0)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_TLS_CONSTRUCT_SERVER_CERTIFICATE, ERR_R_INTERNAL_ERROR);
          return 0;
      }
      if (!ssl3_output_cert_chain(s, pkt, cpk)) {
          /* SSLfatal() already called */
          return 0;
      }
  
      return 1;
  }
  
  static int create_ticket_prequel(SSL *s, WPACKET *pkt, uint32_t age_add,
                                   unsigned char *tick_nonce)
  {
      /*
       * Ticket lifetime hint: For TLSv1.2 this is advisory only and we leave this
       * unspecified for resumed session (for simplicity).
       * In TLSv1.3 we reset the "time" field above, and always specify the
       * timeout.
       */
      if (!WPACKET_put_bytes_u32(pkt,
                                 (s->hit && !SSL_IS_TLS13(s))
                                 ? 0 : s->session->timeout)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CREATE_TICKET_PREQUEL,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      if (SSL_IS_TLS13(s)) {
          if (!WPACKET_put_bytes_u32(pkt, age_add)
                  || !WPACKET_sub_memcpy_u8(pkt, tick_nonce, TICKET_NONCE_SIZE)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CREATE_TICKET_PREQUEL,
                       ERR_R_INTERNAL_ERROR);
              return 0;
          }
      }
  
      /* Start the sub-packet for the actual ticket data */
      if (!WPACKET_start_sub_packet_u16(pkt)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CREATE_TICKET_PREQUEL,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      return 1;
  }
  
  static int construct_stateless_ticket(SSL *s, WPACKET *pkt, uint32_t age_add,
                                        unsigned char *tick_nonce)
  {
      unsigned char *senc = NULL;
      EVP_CIPHER_CTX *ctx = NULL;
      SSL_HMAC *hctx = NULL;
      unsigned char *p, *encdata1, *encdata2, *macdata1, *macdata2;
      const unsigned char *const_p;
      int len, slen_full, slen, lenfinal;
      SSL_SESSION *sess;
      size_t hlen;
      SSL_CTX *tctx = s->session_ctx;
      unsigned char iv[EVP_MAX_IV_LENGTH];
      unsigned char key_name[TLSEXT_KEYNAME_LENGTH];
      int iv_len, ok = 0;
      size_t macoffset, macendoffset;
  
      /* get session encoding length */
      slen_full = i2d_SSL_SESSION(s->session, NULL);
      /*
       * Some length values are 16 bits, so forget it if session is too
       * long
       */
      if (slen_full == 0 || slen_full > 0xFF00) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                   ERR_R_INTERNAL_ERROR);
          goto err;
      }
      senc = OPENSSL_malloc(slen_full);
      if (senc == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_CONSTRUCT_STATELESS_TICKET, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      ctx = EVP_CIPHER_CTX_new();
      hctx = ssl_hmac_new(tctx);
      if (ctx == NULL || hctx == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                   ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      p = senc;
      if (!i2d_SSL_SESSION(s->session, &p)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                   ERR_R_INTERNAL_ERROR);
          goto err;
      }
  
      /*
       * create a fresh copy (not shared with other threads) to clean up
       */
      const_p = senc;
      sess = d2i_SSL_SESSION(NULL, &const_p, slen_full);
      if (sess == NULL) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                   ERR_R_INTERNAL_ERROR);
          goto err;
      }
  
      slen = i2d_SSL_SESSION(sess, NULL);
      if (slen == 0 || slen > slen_full) {
          /* shouldn't ever happen */
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                   ERR_R_INTERNAL_ERROR);
          SSL_SESSION_free(sess);
          goto err;
      }
      p = senc;
      if (!i2d_SSL_SESSION(sess, &p)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                   ERR_R_INTERNAL_ERROR);
          SSL_SESSION_free(sess);
          goto err;
      }
      SSL_SESSION_free(sess);
  
      /*
       * Initialize HMAC and cipher contexts. If callback present it does
       * all the work otherwise use generated values from parent ctx.
       */
  #ifndef OPENSSL_NO_DEPRECATED_3_0
      if (tctx->ext.ticket_key_evp_cb != NULL || tctx->ext.ticket_key_cb != NULL)
  #else
      if (tctx->ext.ticket_key_evp_cb != NULL)
  #endif
      {
          int ret = 0;
  
          if (tctx->ext.ticket_key_evp_cb != NULL)
              ret = tctx->ext.ticket_key_evp_cb(s, key_name, iv, ctx,
                                                ssl_hmac_get0_EVP_MAC_CTX(hctx),
                                                1);
  #ifndef OPENSSL_NO_DEPRECATED_3_0
          else if (tctx->ext.ticket_key_cb != NULL)
              /* if 0 is returned, write an empty ticket */
              ret = tctx->ext.ticket_key_cb(s, key_name, iv, ctx,
                                            ssl_hmac_get0_HMAC_CTX(hctx), 1);
  #endif
  
          if (ret == 0) {
  
              /* Put timeout and length */
              if (!WPACKET_put_bytes_u32(pkt, 0)
                      || !WPACKET_put_bytes_u16(pkt, 0)) {
                  SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                           SSL_F_CONSTRUCT_STATELESS_TICKET,
                           ERR_R_INTERNAL_ERROR);
                  goto err;
              }
              OPENSSL_free(senc);
              EVP_CIPHER_CTX_free(ctx);
              ssl_hmac_free(hctx);
              return 1;
          }
          if (ret < 0) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                       SSL_R_CALLBACK_FAILED);
              goto err;
          }
          iv_len = EVP_CIPHER_CTX_iv_length(ctx);
      } else {
          EVP_CIPHER *cipher = EVP_CIPHER_fetch(s->ctx->libctx, "AES-256-CBC",
                                                s->ctx->propq);
  
          if (cipher == NULL) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                       SSL_R_ALGORITHM_FETCH_FAILED);
              goto err;
          }
  
          iv_len = EVP_CIPHER_iv_length(cipher);
          if (RAND_bytes_ex(s->ctx->libctx, iv, iv_len) <= 0
                  || !EVP_EncryptInit_ex(ctx, cipher, NULL,
                                         tctx->ext.secure->tick_aes_key, iv)
                  || !ssl_hmac_init(hctx, tctx->ext.secure->tick_hmac_key,
                                    sizeof(tctx->ext.secure->tick_hmac_key),
                                    "SHA256")) {
              EVP_CIPHER_free(cipher);
              SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
          EVP_CIPHER_free(cipher);
          memcpy(key_name, tctx->ext.tick_key_name,
                 sizeof(tctx->ext.tick_key_name));
      }
  
      if (!create_ticket_prequel(s, pkt, age_add, tick_nonce)) {
          /* SSLfatal() already called */
          goto err;
      }
  
      if (!WPACKET_get_total_written(pkt, &macoffset)
                 /* Output key name */
              || !WPACKET_memcpy(pkt, key_name, sizeof(key_name))
                 /* output IV */
              || !WPACKET_memcpy(pkt, iv, iv_len)
              || !WPACKET_reserve_bytes(pkt, slen + EVP_MAX_BLOCK_LENGTH,
                                        &encdata1)
                 /* Encrypt session data */
              || !EVP_EncryptUpdate(ctx, encdata1, &len, senc, slen)
              || !WPACKET_allocate_bytes(pkt, len, &encdata2)
              || encdata1 != encdata2
              || !EVP_EncryptFinal(ctx, encdata1 + len, &lenfinal)
              || !WPACKET_allocate_bytes(pkt, lenfinal, &encdata2)
              || encdata1 + len != encdata2
              || len + lenfinal > slen + EVP_MAX_BLOCK_LENGTH
              || !WPACKET_get_total_written(pkt, &macendoffset)
              || !ssl_hmac_update(hctx,
                                  (unsigned char *)s->init_buf->data + macoffset,
                                  macendoffset - macoffset)
              || !WPACKET_reserve_bytes(pkt, EVP_MAX_MD_SIZE, &macdata1)
              || !ssl_hmac_final(hctx, macdata1, &hlen, EVP_MAX_MD_SIZE)
              || hlen > EVP_MAX_MD_SIZE
              || !WPACKET_allocate_bytes(pkt, hlen, &macdata2)
              || macdata1 != macdata2) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                   SSL_F_CONSTRUCT_STATELESS_TICKET, ERR_R_INTERNAL_ERROR);
          goto err;
      }
  
      /* Close the sub-packet created by create_ticket_prequel() */
      if (!WPACKET_close(pkt)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATELESS_TICKET,
                   ERR_R_INTERNAL_ERROR);
          goto err;
      }
  
      ok = 1;
   err:
      OPENSSL_free(senc);
      EVP_CIPHER_CTX_free(ctx);
      ssl_hmac_free(hctx);
      return ok;
  }
  
  static int construct_stateful_ticket(SSL *s, WPACKET *pkt, uint32_t age_add,
                                       unsigned char *tick_nonce)
  {
      if (!create_ticket_prequel(s, pkt, age_add, tick_nonce)) {
          /* SSLfatal() already called */
          return 0;
      }
  
      if (!WPACKET_memcpy(pkt, s->session->session_id,
                          s->session->session_id_length)
              || !WPACKET_close(pkt)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CONSTRUCT_STATEFUL_TICKET,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      return 1;
  }
  
  int tls_construct_new_session_ticket(SSL *s, WPACKET *pkt)
  {
      SSL_CTX *tctx = s->session_ctx;
      unsigned char tick_nonce[TICKET_NONCE_SIZE];
      union {
          unsigned char age_add_c[sizeof(uint32_t)];
          uint32_t age_add;
      } age_add_u;
  
      age_add_u.age_add = 0;
  
      if (SSL_IS_TLS13(s)) {
          size_t i, hashlen;
          uint64_t nonce;
          static const unsigned char nonce_label[] = "resumption";
          const EVP_MD *md = ssl_handshake_md(s);
          int hashleni = EVP_MD_size(md);
  
          /* Ensure cast to size_t is safe */
          if (!ossl_assert(hashleni >= 0)) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_NEW_SESSION_TICKET,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
          hashlen = (size_t)hashleni;
  
          /*
           * If we already sent one NewSessionTicket, or we resumed then
           * s->session may already be in a cache and so we must not modify it.
           * Instead we need to take a copy of it and modify that.
           */
          if (s->sent_tickets != 0 || s->hit) {
              SSL_SESSION *new_sess = ssl_session_dup(s->session, 0);
  
              if (new_sess == NULL) {
                  /* SSLfatal already called */
                  goto err;
              }
  
              SSL_SESSION_free(s->session);
              s->session = new_sess;
          }
  
          if (!ssl_generate_session_id(s, s->session)) {
              /* SSLfatal() already called */
              goto err;
          }
          if (RAND_bytes_ex(s->ctx->libctx, age_add_u.age_add_c,
                            sizeof(age_add_u)) <= 0) {
              SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                       SSL_F_TLS_CONSTRUCT_NEW_SESSION_TICKET,
                       ERR_R_INTERNAL_ERROR);
              goto err;
          }
          s->session->ext.tick_age_add = age_add_u.age_add;
  
          nonce = s->next_ticket_nonce;
          for (i = TICKET_NONCE_SIZE; i > 0; i--) {
              tick_nonce[i - 1] = (unsigned char)(nonce & 0xff);
              nonce >>= 8;
          }
  
          if (!tls13_hkdf_expand(s, md, s->resumption_master_secret,
                                 nonce_label,
                                 sizeof(nonce_label) - 1,
                                 tick_nonce,
                                 TICKET_NONCE_SIZE,
                                 s->session->master_key,
                                 hashlen, 1)) {
              /* SSLfatal() already called */
              goto err;
          }
          s->session->master_key_length = hashlen;
  
          s->session->time = (long)time(NULL);
          if (s->s3.alpn_selected != NULL) {
              OPENSSL_free(s->session->ext.alpn_selected);
              s->session->ext.alpn_selected =
                  OPENSSL_memdup(s->s3.alpn_selected, s->s3.alpn_selected_len);
              if (s->session->ext.alpn_selected == NULL) {
                  SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                           SSL_F_TLS_CONSTRUCT_NEW_SESSION_TICKET,
                           ERR_R_MALLOC_FAILURE);
                  goto err;
              }
              s->session->ext.alpn_selected_len = s->s3.alpn_selected_len;
          }
          s->session->ext.max_early_data = s->max_early_data;
      }
  
      if (tctx->generate_ticket_cb != NULL &&
          tctx->generate_ticket_cb(s, tctx->ticket_cb_data) == 0)
          goto err;
  
      /*
       * If we are using anti-replay protection then we behave as if
       * SSL_OP_NO_TICKET is set - we are caching tickets anyway so there
       * is no point in using full stateless tickets.
       */
      if (SSL_IS_TLS13(s)
              && ((s->options & SSL_OP_NO_TICKET) != 0
                  || (s->max_early_data > 0
                      && (s->options & SSL_OP_NO_ANTI_REPLAY) == 0))) {
          if (!construct_stateful_ticket(s, pkt, age_add_u.age_add, tick_nonce)) {
              /* SSLfatal() already called */
              goto err;
          }
      } else if (!construct_stateless_ticket(s, pkt, age_add_u.age_add,
                                             tick_nonce)) {
          /* SSLfatal() already called */
          goto err;
      }
  
      if (SSL_IS_TLS13(s)) {
          if (!tls_construct_extensions(s, pkt,
                                        SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
                                        NULL, 0)) {
              /* SSLfatal() already called */
              goto err;
          }
          /*
           * Increment both |sent_tickets| and |next_ticket_nonce|. |sent_tickets|
           * gets reset to 0 if we send more tickets following a post-handshake
           * auth, but |next_ticket_nonce| does not.  If we're sending extra
           * tickets, decrement the count of pending extra tickets.
           */
          s->sent_tickets++;
          s->next_ticket_nonce++;
          if (s->ext.extra_tickets_expected > 0)
              s->ext.extra_tickets_expected--;
          ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
      }
  
      return 1;
   err:
      return 0;
  }
  
  /*
   * In TLSv1.3 this is called from the extensions code, otherwise it is used to
   * create a separate message. Returns 1 on success or 0 on failure.
   */
  int tls_construct_cert_status_body(SSL *s, WPACKET *pkt)
  {
      if (!WPACKET_put_bytes_u8(pkt, s->ext.status_type)
              || !WPACKET_sub_memcpy_u24(pkt, s->ext.ocsp.resp,
                                         s->ext.ocsp.resp_len)) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CERT_STATUS_BODY,
                   ERR_R_INTERNAL_ERROR);
          return 0;
      }
  
      return 1;
  }
  
  int tls_construct_cert_status(SSL *s, WPACKET *pkt)
  {
      if (!tls_construct_cert_status_body(s, pkt)) {
          /* SSLfatal() already called */
          return 0;
      }
  
      return 1;
  }
  
  #ifndef OPENSSL_NO_NEXTPROTONEG
  /*
   * tls_process_next_proto reads a Next Protocol Negotiation handshake message.
   * It sets the next_proto member in s if found
   */
  MSG_PROCESS_RETURN tls_process_next_proto(SSL *s, PACKET *pkt)
  {
      PACKET next_proto, padding;
      size_t next_proto_len;
  
      /*-
       * The payload looks like:
       *   uint8 proto_len;
       *   uint8 proto[proto_len];
       *   uint8 padding_len;
       *   uint8 padding[padding_len];
       */
      if (!PACKET_get_length_prefixed_1(pkt, &next_proto)
          || !PACKET_get_length_prefixed_1(pkt, &padding)
          || PACKET_remaining(pkt) > 0) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_NEXT_PROTO,
                   SSL_R_LENGTH_MISMATCH);
          return MSG_PROCESS_ERROR;
      }
  
      if (!PACKET_memdup(&next_proto, &s->ext.npn, &next_proto_len)) {
          s->ext.npn_len = 0;
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_NEXT_PROTO,
                   ERR_R_INTERNAL_ERROR);
          return MSG_PROCESS_ERROR;
      }
  
      s->ext.npn_len = (unsigned char)next_proto_len;
  
      return MSG_PROCESS_CONTINUE_READING;
  }
  #endif
  
  static int tls_construct_encrypted_extensions(SSL *s, WPACKET *pkt)
  {
      if (!tls_construct_extensions(s, pkt, SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
                                    NULL, 0)) {
          /* SSLfatal() already called */
          return 0;
      }
  
      return 1;
  }
  
  MSG_PROCESS_RETURN tls_process_end_of_early_data(SSL *s, PACKET *pkt)
  {
      if (PACKET_remaining(pkt) != 0) {
          SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_END_OF_EARLY_DATA,
                   SSL_R_LENGTH_MISMATCH);
          return MSG_PROCESS_ERROR;
      }
  
      if (s->early_data_state != SSL_EARLY_DATA_READING
              && s->early_data_state != SSL_EARLY_DATA_READ_RETRY) {
          SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_END_OF_EARLY_DATA,
                   ERR_R_INTERNAL_ERROR);
          return MSG_PROCESS_ERROR;
      }
  
      /*
       * EndOfEarlyData 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_END_OF_EARLY_DATA,
                   SSL_R_NOT_ON_RECORD_BOUNDARY);
          return MSG_PROCESS_ERROR;
      }
  
      s->early_data_state = SSL_EARLY_DATA_FINISHED_READING;
      if (!s->method->ssl3_enc->change_cipher_state(s,
                  SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_SERVER_READ)) {
          /* SSLfatal() already called */
          return MSG_PROCESS_ERROR;
      }
  
      return MSG_PROCESS_CONTINUE_READING;
  }
  