KR20040021305A - Secure remote access system and method for universal plug and play - Google Patents

Abstract

The present invention relates to a remote secure access system and method of a UPnP network, and more particularly, to maintain security reliability when accessing a home network remotely using dynamic download of a CP program module. The present invention for this purpose provides a home agent 411 provided in the home network to communicate with UPnP devices in the home network using IP multicast, and provides an interface to the user and inputs authentication information when remotely accessing the home network. And a remote terminal 431/432 having a remote control point to download a specific function from the home agent if necessary, an access server 412 for managing access to a home agent, and the remote terminal 431/432. When the connection is secured to the access server 412 and the authentication of the remote terminal 431/432 in the access server 412 is successful, the remote terminal 431/432 from the access server 412 An internet gateway (IGD) 413 securely connects to the home agent 411 and functions as a UPnP control point (CP) with the home agent 411. It characterized in that the dispersion formed by a remote terminal (431/432).

Description

SECURE REMOTE ACCESS SYSTEM AND METHOD FOR UNIVERSAL PLUG AND PLAY}

TECHNICAL FIELD The present invention relates to UPnP networks, and more particularly to remote secure access systems and methods.

The communication between two or more devices in a home is also called a home network.

Currently, home networks used in homes include data networks that connect various peripheral devices and share Internet usage with PCs, and AV networks for multimedia data transmission between AV products such as video and TV. Networks for controlling devices are also actively developed and disseminated.

UPnP (Universal Plug and Play) has been proposed as an attempt to integrate networks in current homes.

UPnP is a defacto industry standard that many companies have created and built on the UPnP forum (http://www.upnp.org).

As illustrated in the configuration diagram of FIG. 1, the UPnP network includes a control point for controlling a device and a plurality of devices for providing a service.

Accordingly, since the control point CP provides a user interface, the user can input a command to the control point through the user interface to find (discovery, description) and control various devices. .

In addition, since the control point and the device are configured using the IP protocol, even if the data network, the AV network, and the control network in the home communicate using different physical media, it is possible to integrate them into one network if only IP is supported. Do.

Currently, the UPnP device architecture version 1.0 uses Internet protocols such as TCP / IP and HTTP, and technologies such as eXtensible Markup Language (XML) and Simple Object Access Protocol (SOAP).

That is, the protocol stack structure for configuring the UPnP network includes a network layer 211 including IP and a transport layer including UDP and TCP, as shown in the exemplary diagram of FIG. 2. 212 and presentation / session including technologies such as HTTP, eXtensible Markup Language (XML), Simple Object Access Protocol (SOAP), Simple Service Discovery Protocol (SSDP), and technologies such as Generic Event Notification Architecture (GENA). It is composed of a layer (Presentation / Session Layer) 213, and an Application Layer (214) including related information such as UPnP devices, forums, operators.

In the UPnP network system using the UPnP protocol stack, communication between a control point (hereinafter, abbreviated as CP) and a device is defined in six steps as follows.

(One). Addressing step where devices are assigned IP addresses

(2). Discovery step where CPs discover the device's presence

(3). Description step in which the CP obtains the device and service information supported by the device

(4). Control phase in which the CP calls a device service

(5). Eventing stage in which the device notifies the CP of its state transition

(6). Presentation stage in which the device shows its status and control information

Thus, by using the functions defined above, the user can configure a home network without complicated network settings.

When a UPnP device joins a network, it receives its IP address using Dynamic Host Configuration Protocol (DHCP) or, if there is no DHCP server in the network, uses the automatic IP function to randomly configure IP within a specific subnet to It is used after checking whether or not duplicate usage of. This is called addressing.

The discovery step is a process in which CPs find UPnP devices in a network, using a simple service discovery protocol (SSDP).

If the device is added to the network, the device transmits an SSD (alive) message to the network using the IP multicast function, and the CP receives the appearance message to determine whether the device exists.

In addition, when the CP joins the network newly, the CP multicasts an SSD-search message (m-search) message to the network, and UPnP devices confirming the search message send a response message containing their information to the CP. do.

In addition, the CP checks the response message and, if desired, may request the device for detailed information related to the device, and the received device sends its information as an XML document. The XML document contains URL information about the presentation HTML page for the device. This process is called a description.

If the CP wants to control an arbitrary device, a desired service is sent to the device using SOAP based on the device description. SOAP is a protocol written in XML over HTTP for the purpose of remote function calls.

Finally, if the device wants to receive an event message, the CP sends a subscription request for the event to the device. If the subscription is successful, the device sends an event message to the CP using GENA.

Meanwhile, the development of mobile communication service technology has enabled mobile communication terminals to perform various data communication functions.

Therefore, although the mobile wireless terminal exhibits limited performance in comparison with a PC and a wired Internet service in terms of computing power, storage capacity, power usage, and communication speed due to the characteristics of the device, the mobile wireless terminal is now widely used in the mobile communication service. The necessity of remote access service of home network that can control the equipment in the home and monitor the status is emerging.

However, at present, the UPnP device architecture version 1.0 does not consider a remote access service assuming that all home network components are in the local network.

If the CP exists in the external network and accesses the home network, the following factors should be considered.

(One). Security must be maintained.

(2). It must be able to traverse the Network Address Translation (NAT) firewall of the Internet Gateway Device (IGD).

(3). The UPnP protocol mechanism must be available to the external network.

(4). In order for a CP to operate in a wireless terminal, it is necessary to consider the limited computing power, storage, display capability and network environment of the wireless terminal.

Therefore, the problems of applying the above considerations to the current UPnP device architecture version 1.0 are as follows.

First, although the UPnP security working group proposes a certificate-based security system, there is no particular consideration for remote access. In particular, due to the nature of the remote environment, which can be accessed from any computer, a password-based authentication method is more necessary than a certificate-based method, but this method is not considered.

Second, in order to connect to a server in a home gateway (IGD) NAT firewall, port mapping between private and public IP must be preceded by a well known port. If any home network is connected to any unauthorized connection, Allowing access to your device can be a security issue. On the other hand, the current UPnP standard does not provide a concrete plan.

Third, the UPnP search function is based on IP multicast, but if the CP is located in an external network instead of the local network, there is a problem in that the device search is difficult to operate normally because multicasting is difficult.

In addition, the UPnP device architecture 1.0 does not pay special attention to the wireless terminal environment.

However, in the wireless network to which the UPnP device architecture 1.0 is applied, frequent event message delivery may not be suitable for the wireless environment.

That is, due to the limitation of the display device, the presentation page used by wires needs to be reconfigured in consideration of the wireless environment, and since the terminal may not use the TCP / IP and HTTP stacks, a countermeasure is also required. In order to control various UPnP devices, the function and interface of the CP must also be diversified, but there is a problem in that the memory of the wireless terminal is limited.

Accordingly, an object of the present invention is to provide a remote secure access system and method for a UPnP network, which is designed to provide a security service for safely and effectively accessing a home network from a remote location in order to improve a conventional problem.

In particular, an object of the present invention is to maintain the reliability of security when accessing the home network from a remote location by using dynamic download of the CP program module.

1 is a block diagram of a general UPnP network.

Figure 2 is an exemplary view showing the structure of the UPnP protocol stack.

Figure 3 is a block diagram showing the structure of a remote CP in an embodiment of the present invention.

4 is a block diagram of a UPnP home network system for an embodiment of the present invention.

5 is an operational flowchart for a secure connection between a home agent and a remote terminal in an embodiment of the present invention.

6 is an operational flowchart for a process of exchanging information between a home agent and a remote terminal in an embodiment of the present invention.

7 is an operational flowchart for downloading a special component in an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

411: Home Agent 412: Access Server

413: Internet gateway (IGD) 421 422: component distribution server

431,432: remote terminal

In order to achieve the above object, the present invention provides a method for distributing a function of a UPnP control point (CP) in a home network to communicate with UPnP devices in a home network by performing device discovery and eventing functions using IP multicast. A remote control point provided in the wireless terminal to provide a home agent and an interface to a user and to input authentication information when the remote access to the home network and to download a specific function from the home agent when necessary in a secure connection state (hereinafter, (Abbreviated as a remote CP), an access server managing a connection to a home agent, and a secure connection to the access server by recognizing an encryption method when the remote CP connects, and authentication of the remote CP is successful at the access server. The remote CP from the access server to the home. Provided with a Internet gateway (hereinafter abbreviated as Internet Gateway, hereinafter IGD) for secure connection to the agent is characterized in that configuration.

The present invention is characterized by further comprising a component distribution server for providing a specific component of the device and the seller to the home agent on a network accessible by the home agent.

The IGD provides a port number known as an external network in case of supporting network address translation (hereinafter, abbreviated as NAT) service and converts the IP packet into an access server to the IP address and port number of the IP packet that is connected to the corresponding port. It is characterized by.

The access server is characterized in that the remote CP is configured to modify the NAT mapping table of the IGD based on the NAT configuration service of the UPnP IGD for direct communication with the home agent or device.

In addition, the present invention is to authenticate and secure access by accessing the access server located in the IGD or home agent from the remote terminal in order to achieve the above object, the home agent handed the device information on the home network to the remote terminal and Receiving the device and the terminal's own information to be controlled from the remote terminal, and based on the information received from the remote terminal, the home agent searches for and downloads the appropriate device / vendor specific component (special component) in the component distribution server And the home agent executing the home agent special component by referring to the information of the device and the remote terminal pair, and transmitting the special component for the terminal to be executed in the remote terminal.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The UPnP CP can be logically divided into a function of calling a service provided by a UPnP device and a user interface function of providing an interface to a user.

In the remote CP for the embodiment of the present invention, the UPnP search function must be inside the home network, and the user interface must exist in the remote terminal.

That is, the UPnP control point for the embodiment of the present invention, as shown in the block diagram of Figure 3, in distributing the function of the UPnP control point to the home agent (HA) 320 and the remote control point 331, Provides a home agent 320 and a user interface 332 provided in the home network 310 to communicate with UPnP devices in the home network 310 by performing a device search and event function using IP multicast. And a wireless terminal that downloads a specific function from the home agent 320 and transmits authentication information input by the user to the home agent 310 when accessing the home network 310 when accessing the home network 310. It is configured to include a remote CP 331 provided in.

In FIG. 3, a reliable 1: 1 connection is allocated between the home agent 320 and the remote CP 331, and the 1: 1 connection is a three-layer method such as IPSec, a four-layer method such as TLS or WTLS, or a UPnP security ( Application layer method using security) can be applied.

For example, between the home agent 320 and the remote CP 331, a vendor-specific protocol that can process remote services between each other is defined, and a secure channel for reliable communication between each other is defined. It is connected and configured.

In addition, in the embodiment of the present invention, various functions of the CP may be distributed to the home agent 320 in the home network and the remote CP 331 in the remote terminal in consideration of the performance of the remote terminal and the environment of the network. .

UPnP protocol stack for the embodiment of the present invention is configured to include the basic Internet protocol, the portion defined in the UPnP device architecture, and the portion specialized for each type of equipment and manufacturer, similar to the example of FIG. do.

Here, the basic and common services defined in the UPnP device architecture are made and processed by the UPnP API, and device / seller-specific components for processing services specialized for each device and manufacturer are also implemented using the UPnP API.

For example, a device-specific component may execute a control command for controlling an IGD, a TV, a media renderer, and the like, and a vendor-specific component may execute a control command implemented by a specific seller only on his or her equipment.

That is, in embodiments of the present invention, it is possible to separate device / seller-specific component elements that are device-specific or vendor-specific in the home agent 320 or remote CP 331.

Therefore, in the embodiment of the present invention, when the CP function is properly distributed to the home agent 320 and the remote CP 331 in consideration of the environment of the terminal, and a secure connection is formed between each other, the home agent 320 and the remote CP 331 are provided. ) Can achieve a single CP function by interacting using distributed object technology, and so the home agent 320 operates the same as the existing CP. Can be provided.

On the other hand, if the function is separated into a device / seller specific components for the home agent 320 and the remote CP 331 as described above, it can configure a UPnP home network system as shown in FIG.

That is, Figure 4 is a block diagram of a UPnP home network system for an embodiment of the present invention, as shown here, a device such as a PC, a refrigerator, a TV, a home agent 411, an access server 412 and A home network composed of IGDs 413, a carrier network composed of component distribution servers 421 and 422 accessible by the home agent 411 to distribute device / seller-specific components, and a radio having a built-in remote CP function. It consists of a remote network consisting of a terminal 431 or a user PC (432).

The access server 412 resides in a home network or at a home agent 411 or an internet gateway (hereinafter abbreviated as IGD) 413, authenticates and connects to a connection from a remote terminal 431 or 432. Send information from the remote terminal 431 or 432 to the agent 411 to the home agent 411 and receive a user command from a remote location to control a plurality of network devices and transmit the status of the devices to the remote user. Configure.

The IGD 413 supports services such as packet forwarding and IP address translation, and when supporting a NAT service for IP address translation, provides a port number that is well known as an external network to access the home network from the external network and statically It is configured to match the IP packet coming into the port with the private IP address and the port number of the access server 412.

The component distribution server 421 or 422 is configured to download the specific component to the UPnP CP via the Internet when the device / seller specific component is needed. If the component distribution server 421 and 422 is assumed to have a very small role, the component distribution server 421 and 422 may be included in the access server 412.

Referring to the operation and effect of the embodiment of the present invention configured as described above are as follows.

In an embodiment of the present invention, an external remote terminal 431 or 432 performs a series of processes as shown in the operation flowcharts of FIGS. 5 to 7 to perform a CP function appropriate to a device to safely access and control a home network. .

5 is an operation flowchart for a secure connection between a home agent 411 and a remote terminal 431 or 432, that is, a remote CP.

First, the remote terminal 431 or 432 confirms the encryption scheme supported by each other for secure connection with the access server 412 (S501).

In this case, when the encryption scheme is operated in the third layer such as IPSec, a secure connection is made from the remote terminal 431 or 432 to the IGD 413, and then accesses the access server 412. (S502, S504)

If the PC on the home network equipped with the access server 412 supports IPSec, a secure connection is performed to the PC.

When the encryption scheme operates in an end-to-end scheme such as TLS or WTLS, a secure connection is executed from the remote terminal 431 or 432 to the access server 412. (S503, S504)

When the secure connection is completed in the above, the remote terminal 431 or 432 undergoes an authentication process at the access server 412 (S505 to S509).

In the authentication process, the remote terminal 431 or 432 transmits its ID and password to the access server 412 if the authentication method is password-based (S506), and if the certificate is based on the certificate, the remote terminal 431 or 432 receives the certificate. Authentication is made (S508) by submitting to the server 412 (S507).

Subsequently, if authentication is successful according to the authentication result, the access server 412 informs the home agent 411 of the IP address and listen port number of the authenticated terminal, and the home agent 411 is a remote terminal 431. Alternatively, it assigns its own port for connection with 432) and adds a NAT mapping table to the IGD 413 with the corresponding port information (S509 to S5512).

Accordingly, the IGD 413 establishes a secure connection between the home agent 411 and the remote terminal 431 or 432 and terminates the connection between the access server 412 and the remote terminal 431 or 432. (S513, S514)

If the authentication fails, the IGD 413 terminates the connection between the access server 412 and the remote terminal 431 or 432. (S509, S514)

That is, in the embodiment of the present invention, the external remote terminal 431 or 432 accesses the access server 412 located in the home network, authenticates the user, and establishes a secure connection with the home agent 411.

6 is an operation flowchart for information exchange between a home agent 411 and a remote terminal 431 or 432, that is, a remote CP, which will be described below.

The home agent 411 generates a list of device information in the home network through a UPnP search process and transmits it to the remote terminal 431 or 432. (S601)

When the device to be controlled is selected, the remote terminal 431 or 432 checks whether or not the device already has detailed information on the device. (S602, S603)

At this time, if he or she has detailed information of the device to be controlled, the remote terminal 431 or 432 outputs detailed information of the device.

If the mobile terminal 431 or 432 does not have the detailed information of the device to be controlled, the remote terminal 431 or 432 requests the home agent 411 for the detailed information about the device and the detailed information about the device from the home agent 411. Alternatively, the corresponding URL is received and detailed information about the corresponding device is output using the received information. (S605, S606, S604)

Subsequently, in the case of actually controlling the corresponding device, the remote terminal 431 or 432 transmits the device and its information to the home agent 411 to be controlled (S607, S608).

Here, the information on the remote terminal 431 or 432 may be a manufacturer / model name / OS / software version / virtual machine type and the like.

That is, in the embodiment of the present invention, the home agent 411 transfers the device information on the home network to the remote terminal 431 or 432 and transfers the information of the device and the terminal itself to be controlled from the remote terminal 431 or 432. Receive.

7 is an operation flowchart for searching for and downloading a special component.

The home agent 411 configures information of the device and the terminal pair, and checks whether the device / seller-specific components are cached for the corresponding device and the terminal pair, for example, corresponding special components (S701 and S702).

At this time, if the special component is not caching, the home agent 411 checks the component distribution server 421 or 422 on the Internet from information received from the remote terminal 431 or 432 or the device, and the component distribution server 421 or If 422 is confirmed, the component distribution server 421 or 422 is connected to search for device / seller-specific components for the device and the terminal pair (S703, S704).

Accordingly, when the device / seller specific components are found, the home agent 411 downloads the special components for the device and the terminal pair (S705 and S706).

That is, in the embodiment of the present invention, the home agent 411 searches for a suitable special component in the component distribution server 421 or 422 based on the information received from the remote terminal 431 or 432 and downloads the searched special component. .

Accordingly, the home agent 411 executes the home agent component based on the device / seller-specific component pair downloaded from the component distribution server 421 or 422 and secures the remote CP component in the process of FIG. 5. It is possible to configure a desired UPnP CP between specific device terminals by transmitting and executing the remote terminal 431 or 432 through the connection.

As described in detail above, the present invention can ensure reliable access to the home network from the outside by maintaining a reliable secure connection in the exchange of information between the remote terminal and the home agent that properly distributed the CP function of the UPnP home network. It works.

In addition, the present invention has the effect of making a variety of functions of the UPnP CP by making various additions to each device / seller specific components that are suitable for the remote terminal and the type of device and to download them dynamically have.

That is, according to the present invention, the UPnP CP that supports various services that are not limited to the wireless mobile communication environment while complying with the UPnP device architecture standard enables remote home access while maintaining reliable security. By doing so, it is possible to improve system performance as well as user satisfaction.

Claims (14)

A home agent provided in the home network to communicate with UPnP devices in the home network using IP multicast; A remote terminal including a remote CP to provide an interface to a user and to input authentication information when remote access to the home network and to download a specific function from the home agent when necessary in a secure connection state; An access server for managing a connection between the remote terminal and a home agent; When the remote terminal is connected to the home network securely connected to the access server, and if the authentication of the remote terminal is successful in the access server, the Internet gateway (Internet Gateway) for securely connecting the remote terminal from the access server to the home agent Secure access system of the UPnP network characterized in that the configuration. The method of claim 1, And a component distribution server configured to provide a specific component of a device and a seller to the home agent on a network accessible by a home agent. The Internet gateway of claim 1, wherein A security access system for a UPnP network, characterized by comprising a mapping table for a network address translation (NAT) service. The method of claim 1, wherein the access server is The UPnP IGD's NAT setting service is configured to modify the NAT mapping table of the Internet gateway so that the remote terminal can directly communicate with the home agent or device. The method of claim 1, wherein the access server is Secure access system of UPnP network, characterized in that mounted on the home agent or Internet gateway. In the connection method for combining a home agent and a UPnP CP separated by a remote terminal into a single CP, If the authentication information from the remote terminal is authenticated, and a secure connection to the home agent, and The secure connection step A first process of connecting the remote terminal to the access server for authentication; A second process of mutually transferring information between the remote terminal and the home agent when the authentication is successful; And a third process of securely connecting the remote terminal to the home agent from the connection of the access server. The method of claim 6, wherein the authentication of the first process A secure access method of a UPnP network, characterized by using an ID / password from a remote terminal. The method of claim 6, wherein the second process is The access server informs the home agent of the terminal's IP address and standby port number and adds the port assigned by the home agent to the NAT mapping table of the Internet gateway. The method of claim 6, And a home agent handing the device information on the home network to the remote terminal and receiving the device and the terminal's own information to be controlled from the remote terminal. The method of claim 9, wherein the information exchange step is A first process of the home agent transmitting a list of devices on the home network to a remote terminal; A second process of determining whether a remote terminal has information of a corresponding device when a device to be controlled is selected from the device list; A third process of requesting and downloading the information of the corresponding device by the home agent from the remote terminal if there is no information of the corresponding device; When the control of the device is set, the remote terminal comprises a fourth step of delivering the information to the home agent and the device to the home agent, characterized in that the secure access method of the UPnP network. The device information of claim 10, wherein the device information of the third process is Secure access method of the UPnP network, characterized in that the information or URL of the device. The method of claim 6, The home agent searching for and downloading a suitable device / seller-specific component from the component distribution server based on the information received from the remote terminal; And a home agent executing the special component for the home agent by referring to the information of the device and the remote terminal pair, transmitting the special component for the terminal, and executing the special component for the terminal in the remote terminal. The method of claim 12, wherein the component down step is A first step in which the home agent configures device and terminal pair information and checks whether there is a special component corresponding to the configured device and terminal pair; A second process of searching for a special component on a network accessible by the home agent based on information received from a remote terminal or a device when there is no special component; When the special component is found in the above, the home agent has a third process of downloading the special component. In the connection method for combining a home agent and a UPnP CP separated by a remote terminal into a single CP, A first step of establishing a secure connection with a home agent when the remote terminal is connected to the access server and authenticated A second step in which the home agent transmits the device information on the home network to the remote terminal and receives information of the device to be controlled from the remote terminal and the terminal itself when the secure connection is made; A third step of the home agent searching for and downloading a device / seller-specific component from the component distribution server by referring to the information received from the above; And a fourth step in which the home agent executes the home agent special component by referring to the information of the device and the remote terminal pair, and transmits the special component for the terminal to be executed in the remote terminal.