schannel_connect_step3(struct Curl_easy *data, struct connectdata *conn,
                       int sockindex)
{
  CURLcode result = CURLE_OK;
  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
  SECURITY_STATUS sspi_status = SEC_E_OK;
  CERT_CONTEXT *ccert_context = NULL;
  bool isproxy = SSL_IS_PROXY();
#ifdef DEBUGBUILD
  const char * const hostname = SSL_HOST_NAME();
#endif
#ifdef HAS_ALPN
  SecPkgContext_ApplicationProtocol alpn_result;
#endif

  DEBUGASSERT(ssl_connect_3 == connssl->connecting_state);

  DEBUGF(infof(data,
               "schannel: SSL/TLS connection with %s port %hu (step 3/3)\n",
               hostname, conn->remote_port));

  if(!BACKEND->cred)
    return CURLE_SSL_CONNECT_ERROR;

  /* check if the required context attributes are met */
  if(BACKEND->ret_flags != BACKEND->req_flags) {
    if(!(BACKEND->ret_flags & ISC_RET_SEQUENCE_DETECT))
      failf(data, "schannel: failed to setup sequence detection");
    if(!(BACKEND->ret_flags & ISC_RET_REPLAY_DETECT))
      failf(data, "schannel: failed to setup replay detection");
    if(!(BACKEND->ret_flags & ISC_RET_CONFIDENTIALITY))
      failf(data, "schannel: failed to setup confidentiality");
    if(!(BACKEND->ret_flags & ISC_RET_ALLOCATED_MEMORY))
      failf(data, "schannel: failed to setup memory allocation");
    if(!(BACKEND->ret_flags & ISC_RET_STREAM))
      failf(data, "schannel: failed to setup stream orientation");
    return CURLE_SSL_CONNECT_ERROR;
  }

#ifdef HAS_ALPN
  if(BACKEND->use_alpn) {
    sspi_status =
      s_pSecFn->QueryContextAttributes(&BACKEND->ctxt->ctxt_handle,
                                       SECPKG_ATTR_APPLICATION_PROTOCOL,
                                       &alpn_result);

    if(sspi_status != SEC_E_OK) {
      failf(data, "schannel: failed to retrieve ALPN result");
      return CURLE_SSL_CONNECT_ERROR;
    }

    if(alpn_result.ProtoNegoStatus ==
       SecApplicationProtocolNegotiationStatus_Success) {

      infof(data, "schannel: ALPN, server accepted to use %.*s\n",
            alpn_result.ProtocolIdSize, alpn_result.ProtocolId);

#ifdef USE_HTTP2
      if(alpn_result.ProtocolIdSize == ALPN_H2_LENGTH &&
         !memcmp(ALPN_H2, alpn_result.ProtocolId, ALPN_H2_LENGTH)) {
        conn->negnpn = CURL_HTTP_VERSION_2;
      }
      else
#endif
        if(alpn_result.ProtocolIdSize == ALPN_HTTP_1_1_LENGTH &&
           !memcmp(ALPN_HTTP_1_1, alpn_result.ProtocolId,
                   ALPN_HTTP_1_1_LENGTH)) {
          conn->negnpn = CURL_HTTP_VERSION_1_1;
        }
    }
    else
      infof(data, "ALPN, server did not agree to a protocol\n");
    Curl_multiuse_state(data, conn->negnpn == CURL_HTTP_VERSION_2 ?
                        BUNDLE_MULTIPLEX : BUNDLE_NO_MULTIUSE);
  }
#endif

  /* save the current session data for possible re-use */
  if(SSL_SET_OPTION(primary.sessionid)) {
    bool incache;
    struct Curl_schannel_cred *old_cred = NULL;

    Curl_ssl_sessionid_lock(data);
    incache = !(Curl_ssl_getsessionid(data, conn, isproxy, (void **)&old_cred,
                                      NULL, sockindex));
    if(incache) {
      if(old_cred != BACKEND->cred) {
        DEBUGF(infof(data,
                     "schannel: old credential handle is stale, removing\n"));
        /* we're not taking old_cred ownership here, no refcount++ is needed */
        Curl_ssl_delsessionid(data, (void *)old_cred);
        incache = FALSE;
      }
    }
    if(!incache) {
      result = Curl_ssl_addsessionid(data, conn, isproxy, BACKEND->cred,
                                     sizeof(struct Curl_schannel_cred),
                                     sockindex);
      if(result) {
        Curl_ssl_sessionid_unlock(data);
        failf(data, "schannel: failed to store credential handle");
        return result;
      }
      else {
        /* this cred session is now also referenced by sessionid cache */
        BACKEND->cred->refcount++;
        DEBUGF(infof(data,
                     "schannel: stored credential handle in session cache\n"));
      }
    }
    Curl_ssl_sessionid_unlock(data);
  }

  if(data->set.ssl.certinfo) {
    int certs_count = 0;
    sspi_status =
      s_pSecFn->QueryContextAttributes(&BACKEND->ctxt->ctxt_handle,
                                       SECPKG_ATTR_REMOTE_CERT_CONTEXT,
                                       &ccert_context);

    if((sspi_status != SEC_E_OK) || !ccert_context) {
      failf(data, "schannel: failed to retrieve remote cert context");
      return CURLE_PEER_FAILED_VERIFICATION;
    }

    traverse_cert_store(ccert_context, cert_counter_callback, &certs_count);

    result = Curl_ssl_init_certinfo(data, certs_count);
    if(!result) {
      struct Adder_args args;
      args.data = data;
      args.idx = 0;
      args.certs_count = certs_count;
      traverse_cert_store(ccert_context, add_cert_to_certinfo, &args);
      result = args.result;
    }
    CertFreeCertificateContext(ccert_context);
    if(result)
      return result;
  }

  connssl->connecting_state = ssl_connect_done;

  return CURLE_OK;
}