}

/*
 *-------------------------------------------------------------------
 *
 * Session Callback for Clients --
 *
 *	Called when a new session ticket has been received. In TLS 1.3
 *	Called when a new session is added to the cache. In TLS 1.3
 *	this may be received multiple times after the handshake. For
 *	earlier versions, this will be received during the handshake.
 *
 * Results:
 *	None
 *
 * Side effects:

    const unsigned char *session_id;
    int len;
    int code;
    size_t len2;

    dprintf("Called");

    if (statePtr->callback == (Tcl_Obj*)NULL)
	return 0;
    if (statePtr->callback == (Tcl_Obj*)NULL) {
	return SSL_TLSEXT_ERR_OK;
    } else if (ssl == NULL) {
	return SSL_TLSEXT_ERR_NOACK;
    }

    cmdPtr = Tcl_DuplicateObj(statePtr->callback);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("session", -1));

    /* Session id */
    session_id = SSL_SESSION_get0_id_context(session, &len);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(session_id, len));

	Tcl_BackgroundException(interp, code);
#endif
    }
    Tcl_DecrRefCount(cmdPtr);

    Tcl_Release((ClientData) statePtr);
    Tcl_Release((ClientData) interp);
    /* If return non-zero, caller will have to do a SSL_SESSION_free() on the structure. */
    return 1;
    return 0;
}

/*
 *-------------------------------------------------------------------
 *
 * ALPN Callback for Servers --
 *

    State *statePtr = (State*)arg;
    Tcl_Interp *interp	= statePtr->interp;
    Tcl_Obj *cmdPtr;
    int code;

    dprintf("Called");

    if (statePtr->callback == (Tcl_Obj*)NULL)
    if (statePtr->callback == (Tcl_Obj*)NULL) {
	return SSL_TLSEXT_ERR_OK;
    } else if (ssl == NULL) {
	return SSL_TLSEXT_ERR_NOACK;
    }

    /* Select protocol */
    SSL_select_next_proto(out, outlen, statePtr->protos, statePtr->protos_len, in, inlen);

    cmdPtr = Tcl_DuplicateObj(statePtr->callback);
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj("alpn", -1));
    Tcl_ListObjAppendElement(interp, cmdPtr, Tcl_NewStringObj(*out, -1));

    int code;
    const char *servername;
    const unsigned char *p;
    size_t len, remaining;

    dprintf("Called");

    if (statePtr->callback == (Tcl_Obj*)NULL)
	return SSL_CLIENT_HELLO_SUCCESS;
    if (statePtr->callback == (Tcl_Obj*)NULL) {
	return SSL_TLSEXT_ERR_OK;
    } else if (ssl == NULL) {
	return SSL_TLSEXT_ERR_NOACK;
    }

    /* Get names */
    if (!SSL_client_hello_get0_ext(ssl, TLSEXT_TYPE_server_name, &p, &remaining) || remaining <= 2) {
        return SSL_CLIENT_HELLO_ERROR;
    }

    /* Extract the length of the supplied list of names. */

    /*
     * SSL Callbacks
     */
    SSL_set_app_data(statePtr->ssl, (void *)statePtr);	/* point back to us */
    SSL_set_verify(statePtr->ssl, verify, VerifyCallback);
    SSL_CTX_set_info_callback(statePtr->ctx, InfoCallback);
    SSL_CTX_sess_set_new_cb(statePtr->ctx, SessionCallback);

    /* Create Tcl_Channel BIO Handler */
    statePtr->p_bio	= BIO_new_tcl(statePtr, BIO_NOCLOSE);
    statePtr->bio	= BIO_new(BIO_f_ssl());

    if (server) {
	/* Server callbacks */
	SSL_CTX_set_alpn_select_cb(statePtr->ctx, ALPNCallback, (void *)statePtr);
	SSL_CTX_set_tlsext_servername_arg(statePtr->ctx, (void *)statePtr);
	SSL_CTX_set_tlsext_servername_callback(statePtr->ctx, SNICallback);
	SSL_CTX_set_client_hello_cb(statePtr->ctx, HelloCallback, (void *)statePtr);

	statePtr->flags |= TLS_TCL_SERVER;
	SSL_set_accept_state(statePtr->ssl);
    } else {
	/* Session caching */
	SSL_CTX_set_session_cache_mode(statePtr->ctx, SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_NO_INTERNAL_STORE);
	SSL_CTX_sess_set_new_cb(statePtr->ctx, SessionCallback);

	SSL_set_connect_state(statePtr->ssl);
    }
    SSL_set_bio(statePtr->ssl, statePtr->p_bio, statePtr->p_bio);
    BIO_set_ssl(statePtr->bio, statePtr->ssl, BIO_NOCLOSE);

    /*
     * End of SSL Init