Patent Publication Number: US-6990515-B2

Title: Secure method and system to prevent internal unauthorized remotely initiated power up events in computer systems

Description:
BACKGROUND OF THE INVENTION 
   1. Technical Field 
   This invention relates generally to network computing systems, more particularly, to an improved method and system for remotely waking a computer from a network, and still more particularly to an improved method and system for remotely waking a computer from a network wherein the likelihood of an unauthorized remotely initiated wake up is diminished. 
   2. Description of the Related Art 
   Computer networks are commonly used in offices or corporate environments to interconnect personal computers. Well-known local area networks (LANs), such as Ethernet, Token Ring and ARCnet, are widely used to connect a group of computers and other devices that are dispersed over a relatively limited area, such as an office or building, and new LANs continue to be developed. These local area networks provide an efficient and economical way for personal computers to share information and peripherals. 
   Of course, computer networks are not limited to the confines of an office or building. Smaller networks are commonly interconnected into wide area networks (WANs), such as the Internet, to provide a communications link over a larger area. The Internet is actually a collection of networks that share the same namespace and use the TCP/IP protocols. Originally developed for the military in 1969, the Internet now connects over four hundred networks and tens of thousands of nodes in over forty-two countries. It is estimated that the Internet is now accessed by more than 10 million people every day, and that perhaps as many as 513 million people have access to the Internet. 
   As is well known in the art, the transmission of data packets across networks is governed by a set of rules called “transport protocols.” In order for two computers in a local area network to communicate with one another, each computer must use the proper transport protocol for the particular network. During the last decade, many different transport protocols have evolved for different networks. For example, TCP/IP is the transport protocol widely used in UNIX-based networks and with Ethernet 802.3 LANs; IPX/SPX is the transport protocol used by Novell Corporation&#39;s NetWare software; NetBEUI is the local-area transport protocol developed by IBM to operate underneath Microsoft&#39;s NetBIOS network interface; DECnet is the transport protocol used by Digital Equipment Corporation for linking computer systems to DECnet-based networks; AppleTalk is the transport protocol developed by Apple Computer, Inc. for linking computer systems to Apple Macintosh network systems; and XNS is the transport protocol developed by Xerox Corporation that was used in early Ethernet networks. These transport protocols, which are all well known in the art, are often implemented as drivers which can be loaded into and removed from a computer system. 
   In order to connect to a network, a computer is usually provided with one or more network interface cards that provide a data link to the network. Each network interface card has a unique address, referred to herein as its “destination address,” which enables each computer to be individually addressed by any other computer in the network. The destination address is typically, but not always, a 12 digit hexadecimal number (e.g., 00AA00123456) that is programmed into non-volatile memory located on the network interface card and is generally hidden from the user&#39;s view. 
   The destination address of a computer is analogous to a person&#39;s social security number in that, although every person in the country is assigned a unique social security number, it is generally not known to other people and rarely used in normal communications. Likewise, the destination address of a computer is a more primitive means of identifying the computer, and users are not expected to know and remember the destination address of every computer in the network. Instead, every computer generally has a computer name (commonly corresponding to the user&#39;s name and/or machine location) that is more widely known. When a user desires to send a message to another computer, the transport protocol in the network is responsible for converting the computer name into the corresponding destination address to facilitate communicating between the two computers. 
   The network interface card of the destination computer is designed to continually monitor incoming packets over the network. When the network interface card detects an incoming packet containing its destination address, the network interface card will identify itself as the intended recipient of the packet. 
   In full power mode communications transmissions occur between two computers automatically and completely invisible to the user. However, efforts are now being made to extend the use of network computing to power management applications, in which one or more of the computers may be operating in a low power mode. In particular, there is increasing demand for power management systems that minimize the energy consumption of computer systems, yet still allow the possibility for receiving remote communications from other computers via a network. These power management systems must provide a mechanism for “waking” a remote computer system from the network in order to receive the communications. 
   Generally stated, “power management” refers to a computer system&#39;s ability to conserve or otherwise manage the power that it consumes. Although power management concerns were originally focused on battery-powered portable computers, these concerns now extend to AC-powered “desktop” computer systems as well. For example, the United States government now provides strong incentives to those in the computer industry to promote energy efficiency in computers. 
   More particularly, power management refers to the ability to dynamically power down a computer or certain devices when they are not in use, thereby conserving energy. A computer in this condition is referred to herein as being in a “power down” state or condition. Power is then restored to the computer or devices when they are required for use. This process is often referred to as “waking” the computer. 
   A computer in a power down state may be in a “suspended power state” or a “hibernated power state.” In general, a computer in a suspended power state is similar to a computer with all power removed, except that power to memory is maintained and dynamic RAM (DRAM) is refreshed. In addition, the operations of the computer are held in a suspended power state for a suspend operation, whereas the system loses its current operational state on a general power down. 
   A computer in a hibernated power state is similar to the suspended power state, except that the memory states are written to disk and the entire computer system is shut down. 
   Although there are several existing power management systems, most are not designed to operate in a network computing environment. Further, those that are designed to operate in a network are limited in their usefulness. For example, in one prior system for waking a computer from a local area network, a remote wake frame or “magic packet” is defined that includes the destination address repeated 16 times somewhere within the packet. While the computer is in the power down state, its network interface card continually monitors all incoming message packets for one that has its destination address repeated 16 times. When the network interface card detects an incoming packet with this address sequence, the network interface card transmits a signal to the operating system to wake the computer. 
   A significant limitation with this system is that it provides little, if any, security. Anyone with access to the network may send a packet to wake sleeping systems, permitting nuisance attacks where an unauthorized computer wakes systems needlessly on the network. 
   Attempts to solve the security issues associated with waking a remote computer have focused on using passwords in the magic packet. However, passwords only provide limited protection. Once discovered the password may be used by any computer on the network. An unauthorized system may uncover the password by any number of means, including “brute force” or “sniffing.” Brute force password discovery is defined as trying all possibilities until the password is found. Sniffing refers to a machine listening for all packets on the network, including those addressed to other machines. If the sniffed packet is determined to be a magic packet the password is extracted. 
   Therefore, there is a need for an improved method and system of waking a remote computer on a network where the likelihood of an unauthorized remotely initiated wake up is diminished. 
   SUMMARY OF THE INVENTION 
   As will be seen, the foregoing invention satisfies the foregoing needs and accomplishes additional objectives. Briefly described, the present invention provides an improved method and system for remotely waking a client system from a network. In contrast to previous systems, the method and system of the present invention diminishes the likelihood of an unauthorized remotely initiated wake up. 
   According to one aspect of the present invention, a method and system of waking a client system that is in a power down state (the “sleeping computer”) from a computer network is provided. The sleeping computer includes a network interface card that listens for a particular data sequence. The method and system begin when an incoming data packet is transmitted from an administration system in the computer network to the sleeping computer. When the network interface card detects the incoming packet, it searches the incoming packet for the particular data sequence associated with the sleeping computer. If the incoming packet contains the particular data sequence associated with the sleeping computer, the sleeping computer transmits a reply message to the administration system. Upon receiving the reply, the administration system modifies the reply message in a predetermine manner and transmits the modified reply to the sleeping computer. If the sleeping computer determines the reply message was modified in the predetermined manner, then a signal is issued to wake the sleeping computer. Otherwise, the incoming packet is discarded and the sleeping computer is not awakened. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
       FIG. 1  is a schematic diagram illustrating a network of computers within which the present invention may find application. 
       FIG. 2  is a block diagram of the operating environment of a computer within the network of  FIG. 1 , in accordance with of the preferred embodiment. 
       FIG. 3  is a state diagram depicting one preferred set of steps for remotely awakening a computer by another computer on the network. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawing figures, in which like numerals indicate like elements or steps throughout the several views, the preferred embodiment of the present invention will be described. In general, the present invention provides an improved method and system for waking a client system from a network. In contrast to previous systems, the present invention described herein diminishes the likelihood of an unauthorized remotely initiated wake up. 
     FIG. 1  illustrates a schematic diagram of the typical application of the present invention, a client system  10  and an administration system  14  embodying the system of the present invention, and which execute the steps and methods described herein. As show in  FIG. 1 , the client system  10  is in a networked environment with logical connections to one or more remote computers  12   a–b,  any machine on the Internet  22 , and administration system  14 . The logical connections between the client system  10 , remote computers  12   a–b,  any machine on the Internet  22 , and administration system  14  are represented by local area networks  18   a–b,  such as Ethernet, Token Ring, or ARCnet, and a wide area network  30 , such as one created by routers  24   a–c.  It is important to note the wide area network  30  could be composed of a varying number of routers and that local area networks  18   a–b  could contain a varying number of systems. Further, administration system  14  could be any machine connected to the network, but for the purposes of simplifying the illustration it is specified as a particular machine. 
   Referring to  FIG. 1  and  FIG. 2 , the client system  10 , as well as the remote computers  12   a–b  and administration system  14 , also includes at least one network interface card  56  for connecting the hardware of the computers to the local area network  18   a–b  and/or wide area network  30 . The CPU  52  operates to execute an operating system  46  and application programs  48  desired by an operator of the system. The operating system  46  and application programs  48  can be stored within RAM  44 . BIOS  42  resides in read-only memory (ROM)  40  and is responsible for basic input and output. To simplify the representation of a general purpose computer system, conventional computer components, including computer resources such as direct memory access controller, interrupt controller, and I/O controllers, are not shown. However, it will be appreciated that CPU  52  is connected to conventional computer components via one or more system busses  54  that support communications of control, address, and data signals between the CPU  52  and these standard computer components. Remote computers  64   a–c  represent machines logically connected to client system  58  and includes administration system  14  as well as other computer systems connected to the network depicted in  FIG. 1 . 
   In one preferred embodiment of the present invention, a method and system of waking a remote computer from the network is provided. For example, in the diagram shown in  FIG. 1 , a method and system are provided whereby the administration system  14  may wake the client system  10  via the local area network  18   a–b  or wide area network  30 . Conversely, the client system  10  may act as an administration system and utilize the methods and systems described herein to wake any of the remote computers  12   a–b.    
   Referring to  FIG. 1 ,  FIG. 2 , and  FIG. 3 , network interface card  56  in client machine  10  detects the magic packet transmitted from administration system  14  as depicted at step  72 . In response, client system  10  sends a reply to administration system  14  as illustrated at step  74  for authentication. Once administration system  14  receives the reply, the reply is modified in a predetermined manner and transmitted to client machine  10  as depicted at step  76 . Client system  10  verifies the modified packet from administration system  14  was modified in the predetermined manner, and if the modified packet is verified client system  10  awakens. Otherwise, client system  10  continues to sleep. 
   The manner of initially communicating to or from a client system the manner a reply packet is to be modified may be any method known in the art. For example, a secure transmission or predetermined sequence may be utilized. 
   Those skilled in the art will appreciate that the predetermined method of modifying the packet may be by any number of methods known in the art and that the authentication could be performed by a system other than the administration system that sent the original magic packet. Further, those skilled in the art realize the magic packet could be substituted with a packet of different form that performs the same function of provoking the client system to transmit a reply to the administration system for authentication. 
   The present invention has been described in relation to particular embodiments which are intended in all respects to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. For example, although the present invention has been described in accordance with a remote computer in a power down mode, it will be appreciated that the systems and principles described herein may also be useful in a computer that is operating in full power mode by having the network interface card send an interrupt only when it receives a packet that the computer needs to process. Moreover, the present invention has been described in accordance with waking a personal computer. However, the design described herein equally applies to any other computers, servers, network peripherals or network servers. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing discussion.