Abstract:
A method and system for labeling data in a networked environment. The method and system comprise determining if a label should be added to a portion of data having an associated first header. If so, a second header is constructed containing a label. The second header is indicated in a reference in the first header. The label contains at least one attribute of the data. The second header is attached to the first header. The portion of data is then transmitted, along with the headers. In one embodiment, the second header may contain credential information related to the data portion.

Description:
RELATED US PATENT APPLICATION  
       [0001]    This Application is related to U.S. Provisional Application entitled, “GENERALIZED LABELED SECURITY OPTION FOR IPV6,” Application No. 60/356,821, filed on Feb. 13, 2002. This provisional application is hereby incorporated by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to the field of inter-networked devices. Specifically, an embodiment of the present invention relates to a method and system of labeling data to transfer data attributes along with the data.  
           [0004]    2. Background Art  
           [0005]    Estimates of the worldwide damage caused by malware (e.g., viruses, trojan horses, etc.) exceed $1 trillion per year in wasted effort to repair problems, reconstruct damaged data, etc. Trusted operating systems take a proactive approach to the problem by providing strong security features and assurances in accordance with formally stated requirements. They provide a trusted computing base built from the ground up for the purpose of enforcing a security policy (e.g., the set of rules that determine who accesses what and how). The trustworthiness comes from the guarantee, to a certain level of assurance, that all accesses to objects by subjects from software running on the trusted computing base are controlled and cannot compromise the protection mechanisms of the trusted computing base.  
           [0006]    Multilevel security is being increasingly considered outside the traditional governmental and military circles, as it has the potential to meet emerging information technology security needs, when combined with other technologies. In order to guarantee that information is protected to a certain level of assurance, multilevel secure operating systems enforce a set of mandatory access control (MAC) rules that can be evaluated according to predefined criteria.  
           [0007]    In order to enforce those access controls across a network, routing needs to be controlled so as to select specific network links in accordance with the security policy. Also, hosts need to retrieve the security attributes of data coming from the network and to communicate those of their own processes to remote hosts.  
           [0008]    Information in a Multilevel-Secure Operating System, such as Trusted Solaris™, is assigned a label. The label contains attributes used to enforce the access controls required by a security policy. However, the label may be used for purposes other than security. The label of a process (e.g., program) may represent the credentials (e.g., owner, clearance, and privileges) or other attributes of that process. The label of an object (e.g., file, device, etc.) may represent the sensitivity (e.g., confidential, secret, public, engineering use only, etc.), the integrity, or other attributes of the data.  
           [0009]    Implicit labeling is one way of labeling information. A conventional implicit labeling scheme is dedicating an IPsec (Internet Protocol Security) security association for each sensitivity level. However, implicit labeling has numerous shortcomings. First, scalability is limited when using implicit labeling. Implicitly binding security attributes to a security association may be sufficient when the set of values (e.g., sensitivity levels) is small. However, some attributes have a multitude of sensitivity levels. Thus, there needs to be a separate security association for each combination.  
           [0010]    Another shortcoming of implicit labeling is the cost of establishing the security establishment. For example, an IPsec security association may be able to scale down to selectively protect a single socket (one connection/liaison). However, due to the cost of establishing the security association (including the key exchange), it is more efficient to aggregate the flows by broader selectors, such as host or subnet addresses or transport level port numbers.  
           [0011]    A further shortcoming of implicit labeling is the inherent difficulty of using the implicit information to route data packets. For example, a router will not necessarily be a member of the security association. Unless the router is a member, it will not know the security attributes of the packets and hence is unable to route based on the attributes.  
           [0012]    Explicit labeling is another way of labeling information. One conventional method using explicit labeling is an Internet Protocol Version 4 (IPv4) Security Option. However, this method was designed for only a small number of possible labels that are generally not well suited for commercial applications. Furthermore, emerging standards are making IPv4 antiquated.  
           [0013]    Therefore, a problem with conventional methods of labeling information is scalability. Another problem with conventional methods is efficiency. Still another problem with conventional methods is not being able to use the labeling information to route data. A further problem is that some methods lack commercial applicability and are becoming antiquated.  
         SUMMARY OF THE INVENTION  
         [0014]    The present invention provides a method for labeling information in a networked environment. Embodiments of the present invention provide a scalable solution. Embodiments of the present invention also provide an efficient solution. Embodiments of the present invention provide a solution that may be used to route data. Embodiments are suitable for commercial applications. The present invention provides these advantages and others not specifically mentioned above but described in the sections to follow.  
           [0015]    A method and system for labeling data in a networked environment is disclosed. The method and system comprise determining if a label should be added to a portion of data having an associated first header. If so, a second header is constructed containing a label. The second header is indicated in a reference in the first header. The label contains at least one attribute of the data. The second header is attached to the first header. The portion of data is then transmitted, along with the headers. In one embodiment, the second header may contain credential information related to the data portion.  
           [0016]    More specifically, an embodiment of the present invention is directed to: a) determining if a label is to be added to a portion of data having an associated first header; b) constructing a second header comprising the label, wherein the label comprises at least one attribute of the data; c) attaching the second header to the portion of data; and d) transmitting the portion of data along with the first and the second headers.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1A is a diagram illustrating labeling data with headers attached to a data packet, according to embodiments of the present invention.  
         [0018]    [0018]FIG. 1B is a diagram illustrating a network of nodes having tables for processing labeled packets, according to embodiments of the present invention.  
         [0019]    [0019]FIG. 2 is a diagram illustrating the flow of outbound traffic, according to embodiments of the present invention.  
         [0020]    [0020]FIG. 3 is a flowchart illustrating steps of a computer process of labeling data, according to embodiments of the present invention.  
         [0021]    [0021]FIG. 4 is a diagram illustrating a general format for a header extension for labeling data, according to embodiments of the present invention.  
         [0022]    [0022]FIG. 5 is a diagram illustrating a format for option data, according to embodiments of the present invention.  
         [0023]    [0023]FIG. 6 is a flowchart illustrating steps of a computer process of processing packets based on attributes with which the data is labeled, according to embodiments of the present invention.  
         [0024]    [0024]FIG. 7 is an exemplary interface protection table, according to embodiments of the present invention.  
         [0025]    [0025]FIG. 8 is a flowchart illustrating steps of a process of using data in a header to process a packet, according to embodiments of the present invention.  
         [0026]    [0026]FIG. 9 is a diagram illustrating flow of inbound traffic, according to embodiments of the present invention.  
         [0027]    [0027]FIG. 10 is a computer system that may serve as a platform for embodiments of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]    In the following detailed description of the present invention a method for labeling data, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one skilled in the art that the present invention may be practiced without these specific details or with equivalents thereof. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention.  
       Notation and Nomenclature  
       [0029]    Some portions of the detailed descriptions which follow are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that can be performed on computer memory (e.g., processes  300 ,  600 , and  800 ). These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. A procedure, computer executed step, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.  
         [0030]    It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as “indexing” or “processing” or “computing” or “translating” or “calculating” or “determining” or “scrolling” or “displaying” or “recognizing” or “generating” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.  
       Method and System for Labeling Data in a Communications System  
       [0031]    Embodiments of the present invention provide for a method and system of labeling data, such that attributes associated with the data may be transferred with the data. Referring now to FIG. 1A, when a data packet  130  is to be transferred between two nodes, the originating node may label the data packet  130  by constructing one or more headers containing selected attributes. The header may be, for example, an attached header  132 . In one embodiment, the attached header  132  is an Internet Protocol Version 6 (IPv6) extension header. This may be a hop-by-hop extension header, which may include attributes useful when routing the data packet  130 . The attached header  132  may also be an IPV6 destination extension header, which may include attributes useful for processing at a destination node. However, the present invention is not limited to these specific extension headers. Furthermore, the present invention is not limited to IPv6 extension headers. More generally, the headers containing the labels may be any header that is attached to a main or primary header  136 . The attached header or headers  132  are attached to a main header  136  for the data packet  130  and then the data packet  130  and headers  132 ,  136  are delivered to either a routing or a destination node.  
         [0032]    The various nodes involved may agree upon one or more sets of constraints or rules for processing the data packet  130 , based on values in the attached header fields. Referring now to FIG. 1B, the rules may be stored on the nodes in constraint tables  140 , of which there may be one per interface  142 . If a routing or intermediate node  144  receives a data packet  130  that came from an originating node  149 , it may perform an incoming accreditation check to validate that it was proper to receive the data packet  130  on the particular interface  142  on which it arrived. The accreditation check may be based upon values in a hop-by-hop extension header. The routing node  144  may also compare values in a hop-by-hop extension header with a constraint table  140  containing the rules. In this fashion, the data packet  130  may be forwarded into one of the networks  146  based on attributes associated with the data packet  130  that are passed with the data packet  130 .  
         [0033]    When the data packet  130  arrives at the destination node  148 , the destination node  148  may perform an incoming accreditation check to validate that it was proper to receive the data packet  130  on the particular interface  142  on which it arrived. The destination node  148  may perform this check by comparing values in a destination extension header with a set of rules for processing the data packet  130 . The destination node  148  may then deliver the data packet  130  (or a portion thereof) to a process or client on the destination node  148  provided that the data attributes comply with the a set of rules for receiving the data packet  130 . Different sets of rules may are used along the way, for example, each interface  142  may have a different set of rules.  
         [0034]    When a data packet  130  is to be transferred from an originating node  149 , an embodiment of the present invention constructs an attached header  132  having a label for the data attributes. The diagram of FIG. 2 and the computer-implemented process  300  of flowchart of FIG. 3 describe an embodiment of the present invention. Steps of process  300  may be stored as instructions on a computer readable medium and executed on a general-purpose processor. Steps of process  300  may be performed in another order than described in the flowchart. In step  310 , a message is received at a transport layer  150  of the originating node. The message may contain a data packet  130  or other portion of data. The transport layer  150  may use the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), or other protocols that may be suitable for a transport layer  150 .  
         [0035]    The data packet  130  has associated with it certain attributes, for example, security attributes. In one implementation, the message contains not only the data, but also data attributes. However, the data attributes may not be a part of the data packet  130  itself. Furthermore, it is not required that the message include the data attributes, as they may be determined implicitly. For example, within the originating node  149 , the attributes may be discerned by examining file systems, device and process files, etc. However, the data attributes are not generally known by other nodes coupled to the originating node  149 . By attaching a label to the data, other nodes are able to retrieve the data attributes and thus know, for example, the credentials of a remote process and the attributes of data. Thus, remote devices/systems may, for example, enforce access control rules.  
         [0036]    In step  320 , the policy module  160  may perform an export accreditation check, based on the attributes of the data. For example, the policy module  160  may determine if it is acceptable to send the data out a given interface  142  and, if not, to either find an acceptable interface  142  or drop the data packet  130 . The policy module  160  may perform a variety of tasks that are related to policy rules. The present invention is not limited to performing the accreditation check in a policy module  160 . In the event the data packet  130  is dropped, an appropriate message may be delivered to the process that requested the data transfer.  
         [0037]    In step  330 , the originating node  149  determines whether the data packet  130  should be labeled. This determination may be based on a number of factors, for example, the characteristics of the destination node  148 , such as its security family. However, this example is not intended to limit the determination in this fashion. In one implementation the data is passed to a policy module  160 , which determines if a label is needed.  
         [0038]    If a label is needed, a label is constructed using the data attributes, in step  340 . This label may be constructed by the policy module  160 . However, this is not limiting, the label may be constructed by any suitable module. Then the policy module  160  may pass the label a transport module (not shown) with instructions to add an attached header  132  with the provided label. Communication between the policy module  160  and the transport module may be performed by an IPv6 advanced option of the socket API (Application Program Interface), which specifies a programming interface to send ancillary data. The policy module  160  may invoke the kernel side of that API.  
         [0039]    In step  350 , the attached header  132  (e.g., an IPv6 extension header) is constructed at the transport layer  150 . In the case the transport layer  150  is using UDP, everything may happen as if the data were sent using the IPv6 advanced API version of sendmsg( ) with a control message containing a hop-by-hop and/or a destination header, except that the consistency and permission checking may be skipped, because the control message is generated by the kernel.  
         [0040]    In the event the transport layer  150  is using TCP, however, labeling cannot be performed immediately when the messages are received by the transport layer  150  from upstream. Rather, labeling is delayed until the moment the messages are about to be forwarded to the Internet Protocol (e.g., to the network layer  170 ). This is because ancillary data can be sent only using per-endpoint options per-connection and not on a per-packet  130  basis. Furthermore, TCP transmits data packets  130  that are dissociated from a user&#39;s sending system call, like retransmissions, resuming of transmission after window sliding, and control packets.  
         [0041]    Process  300  may build additional labels and construct additional attached headers  132  and add those attached headers  132  to the data packet  130 . It may be that the data packet  130  has a main header  136  that identifies a first attached header  132 , which in turn, identifies a second attached header  132 . For example, one type of header  132  may be intended for routing nodes  144  and another type for a destination node. Whether using TCP, UDP, or another protocol, after the attached header  132  is constructed with the label, the portion of data is sent out the interface  142  of the originating node  149  with the constructed attached header(s)  132 , in step  360 . Process  300  then ends.  
         [0042]    [0042]FIG. 4 illustrates a general format for an attached header  132  that is suitable for delivering the data attributes. In one embodiment, the attached header  132  is an Internet Protocol Version 6 (IPv6) extension header. However, the present invention is not limited to IPv6. The next header field  402  is for specifying the next attached header  132 , if there is one. The payload length field  404  may specify the length of the attached header  132  in units of 32-bit words, minus two. The option field  406  may specify that this attached header  132  contains data attributes or a label. The first two most significant bits (MSB) may be “00” to indicate that non-supporting nodes are to skip over this option and continue processing the data packet  130 . The next MSB may be “0” to indicate that the option data does not change en-route. The remaining five bits of the option type field  406  may be a unique value, which may identify this attached header  132  as containing data attributes.  
         [0043]    Continuing on with the attached-header  132  structure of FIG. 4, the domain of interpretation (DOI) field  410  may be a four-octet integer that identifies the semantics of the attribute field  412 . For example, communicating nodes may agree on a number of sets of rules to be applied to the data attributes. The DOI field  410  may be used to identify which of the sets should be used for the data packet  130  with this attached header  132 . Finally, the attached header  132  may contain an attribute field  412 , which contains one or more tags describing the data attributes.  
         [0044]    Referring now to FIG. 5, an exemplary tag  500  is illustrated. There may be any number of tags  500  in the attribute field  412 . The first field in the tag  500  is a attribute type  502 , which identifies the type of information in the attribute data field  506 . For example, the type of information may relate to sensitivity, clearance, privileges, etc. The tag length  504  specifies the total length of the tag  500 , and may be expressed in octets.  
         [0045]    The following attribute types  502  are described to provide examples of the type of data attributes that may be transferred in the attached header  132 . However, the attribute types  502  are by no means limited to the examples presented in Table 1.  
               TABLE 1                           Attribute Type 1: The attribute may be a hierarchical two-octet entity. Tag       length 504 may equal four. This may be a level or claasification. The       comparison of fields of this may be conventional mathematical relations.       Atrribute Type 2: Non-hierarchical bit-vector. Tag length 504 may be a       variable number of octets. This type may be used for categories/compart-       ments bit sets. The comparison of fields of this type may be the inclu-       sion relation.       Attribute Type 3: Enumeration. Tag length 504 may be a variable number       of octets. This may be a list of items. Each item may be a short integer.       Each item may be a compact way of coding categories and compartments.       The comparison of fields of this type may be the inclusion relation.       Attribute Type 4: List of ranges. Tag length 504 may be a variable number       of octets. Each range may have two shorts: lower and upper boudaries of       the interval. The ranges may be intended as an efficient grouping of cate-       gories and compartments. The comparison of fields of this type may       the inclusion relation.       Attribute Type 5: Destination-only data. Tag length 504 may be a variable       number of octets. Only the destination nodes 148 that understand the DOI       410 may be able to interpret it. This option may not be understood by       router nodes 144 when present in a hop-by-hop header and may thus be       skipped.                  
 
         [0046]    It may be that the data attributes that the originating node  149  wishes a destination node  148  to use are different from the data attributes that the originating node  149  wishes an intermediate or routing node  144  to use. For example, Attribute Type 5 may be intended only for destination nodes  148 . Also, it may be that a tag  500  that is suitable for both destination  148  and routing nodes  144  is to only be used by one of them. Thus, the originating nodes  149  may construct a second attached header  132 . In this fashion, one attached header  132  (e.g., a destination extension header) may be for a destination node  148 , while another attached header  132  (e.g., a hop-by-hop extension header) may be for routing nodes  144 .  
         [0047]    Referring now to the flowchart of FIG. 6, a process  600  in which a node receives a data packet  130  is illustrated. Steps of process  600  may be stored as instructions on a computer readable medium and executed on a general-purpose processor. Steps of process  600  may be performed in another order than described in the flowchart. The node may be either a destination node  148  or a routing node  144 ; however, some details may differ depending on the type of node. For example, a router  144  may forward the data packet  130  to another node while the destination node  148  may deliver the data packet  130  to a process within the destination node  148 . In step  610 , the node receives a data portion or packet  130  via some interface.  
         [0048]    In step  620 , the node determines if the option type  406  specifies that an attached header  132  contains data attributes. A routing node  144  may look at a hop-by-hop extension header, while a destination node  148  may look at a destination extension header. If the data packet  130  does not contain the option type  406  indicating that data attributes are in the attached header  132 , then the process  600  ends. Otherwise, step  630  is taken.  
         [0049]    In step  630 , the node performs an incoming accreditation check to determine if the data packet  130  is allowed to be received into the interface  142  on which is was delivered. This check is based on data attributes in the label in the appropriate attached header  132 , and the constraint table  140  for the receiving interface  142 .  
         [0050]    If the accreditation check fails, the node may send a message, for example an Internet Control Message Protocol (ICMP) message, in step  640 .  
         [0051]    If the accreditation check passes, then step  650  may be performed. If this a routing node  144 , the node determines on which interface  142  to route the data packet  130 . If this is a destination node  148 , then the node determines how to deliver the data packet  130  within the node. For example, the destination node  148  may determine if a process is allowed to have the data packet  130 . This may be performed by comparing values in the attached header  132  with values in a constraint table  140  stored on the node.  
         [0052]    [0052]FIG. 7 illustrates an exemplary constraint table  140  that may be used for the determination in steps  630  or  650  of process  600 . Each node may have a constraint table  140  for each interface  142 . However, a node may have fewer constraint tables  140  than interfaces  142 . A number of domains of interpretation (DOIs) may be specified for each interface  142 . For example, two organizations may agree upon the set of rules that are to be used for each DOI for each interface  142 . The constraint tables  140  may then be loaded onto the nodes in any suitable manner. In this fashion, a different rule  710  may be applied to the same attribute type  502  while processing a data packet  130  at the same interface  142 . Thus, the constraint table  140  shows DOIs 1 through n. For example, for attribute type 1, the rule  710  is that the value of the attribute type  502  (as specified in the attribute data field  506 ) must be between the minimum and maximum value specified in the rule  710 .  
         [0053]    A data packet  130  may be admitted through an interface  142  if its attribute data  506  comply with the rules  710  defined on that interface  142  for the label&#39;s DOI. If the node does not recognize the DOI of the data packet  130  then it may be discarded. For the exemplary attribute types described herein, passing a rule  710  may mean the information as presented in Table 2.  
               TABLE 2                           Attribute Type 1: The attribute data 506 value is within the range in the       rule 710.       Attribute Type 2: All the bits set in the attribute data 506 are set in the bit       vector of the rule 710.       Attribute Type 3: All the items enumerated in the attribute data 506 belong       to either an Attribute Type 3 or an Attribute Type 4 on the interface 142.       Attribute Type 4: All the items in the ranges enumerated in the attribute       data 506 belong to either an Attribute Type 3 or an Attribute Type 4 on the       interface 142.                  
 
         [0054]    [0054]FIG. 8 illustrates a process  800 , which uses a constraint table  140  when processing data packets  130 . Steps of process  800  may be stored as instructions on a computer readable medium and executed on a general-purpose processor. Steps of process  800  may be performed in another order than described in the flowchart. In step  810 , the domain of interpretation field  410  in the attached header  132  is used to determine which set of rules  710  to apply. For example, if the DOI is “2”, then the second row of rules  710  in the constraint table  140  of FIG. 7 may be used.  
         [0055]    In step  820 , the attribute type  502  in the attached header  132  is used to determine which rule  710  to apply. For example, referring to FIG. 7 and assuming that the DOI is “DOI 1”, if the attribute type  502  specifies that it is “attribute type 3,” then the rule  710  is to determine if the attribute data  506  is within the list of items in the set.  
         [0056]    In step  830 , the rule  710  is applied to the value in the attribute data  506  field. If there are more constraints to process, the process  800  returns to step  820 . The process  800  repeats until all constraints in this DOI are processed.  
         [0057]    Referring now to FIG. 9, an inbound traffic flow at a destination node  148  will be described. A message arrives at the network layer  170  from the data link layer  910 . The policy module  160  may then reconstitute the data attributes of the incoming data packet  130  using the same template used by the originating node  149 . If the incoming accreditation check passes, the data packet  130  is kept to be delivered. The message may then be delivered to the correct IP client.  
         [0058]    [0058]FIG. 10 illustrates circuitry of computer system  100 , which may form a platform for embodiments of the present invention. Computer system  100  includes an address/data bus  99  for communicating information, a central processor  101  coupled with the bus  99  for processing information and instructions, a volatile memory  102  (e.g., random access memory RAM) coupled with the bus  99  for storing information and instructions for the central processor  101  and a non-volatile memory  103  (e.g., read only memory ROM) coupled with the bus  99  for storing static information and instructions for the processor  101 . Computer system  100  also includes an optional data storage device  104  (e.g., a magnetic or optical disk and disk drive) coupled with the bus  99  for storing information and instructions.  
         [0059]    With reference still to FIG. 10, system  100  of the present invention also includes an optional alphanumeric input device  106  including alphanumeric and function keys is coupled to bus  99  for communicating information and command selections to central processor unit  101 . System  100  also optionally includes a cursor control device  107  coupled to bus  99  for communicating user input information and command selections to central processor unit  101 . System  100  of the present embodiment also includes an optional display device  105  coupled to bus  99  for displaying information. A network interface  142  coupled to bus  99  provides communication with external devices.  
         [0060]    The preferred embodiment of the present invention a method for labeling data, is thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the below claims.