MILE Working Group K. Moriarty
Internet-Draft S. Tabet
Intended status: Standards Track EMC
Expires: May 10, 2013 D. Waltermire
NIST
November 06, 2012

GRC Report Exchange
draft-ietf-mile-grc-exchange-01.txt

Abstract

Governance, risk, and compliance (GRC) programs provide oversight (governance) of risks and compliance initiatives within an organization. GRC reports are increasingly provided in an XML format. This specification defines a common method to securely transport GRC and other XML reports. The defined messaging capability provides policy options and markings in an XML schema, options for confidentiality at the document/report level, and security for the end-to-end communication. XML reports may be shared between service providers and clients, enterprises, or within enterprises. Reports may also be exchanged for official purposes such as business report filings, compliance report filings, and the handling of legal incidents (eWarrant, eDiscovery, etc.) This work is a generalized format derived from the secure exchange of incident information defined by RFC6545, Real-time Inter-network Defense (RID).

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http:/⁠/⁠datatracker.ietf.org/⁠drafts/⁠current/⁠.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on May 10, 2013.

Copyright Notice

Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http:/⁠/⁠trustee.ietf.org/⁠license-⁠info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.


Table of Contents

1. Introduction

Governance, risk, and compliance (GRC) programs provide oversight (governance) of risks and compliance initiatives within an organization. The areas typically covered by GRC include:

GRC Report Exchange provides a secure method to communicate relevant information and reports, through the automated exchange of extensible markup language (XML) documents. GRC Report Exchange considers security, policy, and privacy issues as related to the exchange of potentially sensitive information. Additionally, it enables organizations accepting GRC report filings, such as service providers or enterprises, the options to make appropriate decisions according to their policy requirements. GRC Report Exchange includes provisions for confidentiality, integrity, and authentication.

The data in GRC reports exchanged are represented in an XML [W3C.REC-xml-20081126] document using the appropriate XML schema for the included report. The XML document or formatted report is then enveloped by the GRC Report Exchange schema to set policy options and provide a common secure exchange method for such documents. By following this model, a single method for all GRC reports can be used, simplifying the integration of GRC reports across platforms.

Security and privacy considerations are of high concern since potentially sensitive information may be passed through GRC Report Exchange messages. GRC Report Exchange takes advantage of XML security and privacy policy information set in the GRC Report Exchange schema and provides standard settings for fine grain controls within GRC XML schemas. The GRC Report Exchange schema acts as an XML envelope to support the communication of GRC report documents. GRC Report Exchange messages are encapsulated for transport, which is defined in a separate document [RFC6546]. The authentication, integrity, and authorization features GRC Report Exchange and RID transport offer are used to achieve a necessary level of security.

GRC report exchange is not strictly a technical problem. There are numerous procedural, trust, and legal considerations that might prevent an organization from sharing information. GRC Report Exchange provides information and options that can be used by organizations who must then apply their own policies for sharing information. Organizations must develop policies and procedures for the use of the GRC Report Exchange protocol and XML reports.

1.1. Normative and Informative

The XML schema [W3C.REC-xmlschema-1-20041028] and transport requirements contained in this document are normative; all other information provided is intended as informative. More specifically, the following sections of this document are intended as informative: Sections XXX. The following sections of this document are normative: Sections XXX.

1.2. Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

2. Report Types

There are many possible report types that may be exchanged using GRC Report Exchange. The reports MUST all be XML formatted reports and MAY leverage the data markings used by this specification to require security options such as encryption on the entire report (XML document) or a section of the report.

The types of reports may vary within each area of GRC. Example report types broken out by GRC focus areas include:

3. Communication between Entities

Trust relationships. Service provider to tenant or client is the most likely scenario for the initial use cases of GRC report exchange. See Section 11.5 on profiles.

3.1. Inter-network Provider GRC Messaging

GRC Report Exchange provides a standard protocol and format that is required to ensure inter-operability between vendors for the exchange and filing of GRC reports. GRC Report Exchange provides the framework necessary for communication between entities exchanging or filing GRC reports. Several message types described in Section 6 are necessary to facilitate the exchange or filing of reports. The message types include the Report, Query, Acknowledgement, Result, and the Request message.

The Report message is used when a GRC report is to be filed on a system or associated database accepting GRC Report Exchange messages, where no further action is required. A Query message is used to request information on a particular report. The Acknowledgement and Report messages are used to communicate the status and result of a Query or Request message.

Use of the communication network and the GRC Report Exchange protocol must be for pre-approved, authorized purposes only. It is the responsibility of each participating party to adhere to guidelines set forth in both a global use policy established through the peering agreements for each bilateral peer or agreed-upon consortium guidelines. The purpose of such policies is to avoid abuse of the system; the policies shall be developed by a consortium of participating entities. The global policy may be dependent on the domain it operates under; for example, a government network or a commercial network such as the Internet would adhere to different guidelines to address the individual concerns. Privacy issues must be considered in public networks such as the Internet. Privacy issues are discussed in the Security Requirements section (Section 11), along with other requirements that must be agreed upon by participating entities.

The GRC Report Exchange system should be configurable to either require user input or automatically provide or file reports. If the trust relationship is not strong, it may not be in the peer's best interest to accept a report or respond to a request. The trust relationship may evolve over time through experience working with a peer and knowledge and review of their policies and operating procedures.

3.2. GRC Report Exchange Communication Topology

The most basic topology for communicating GRC Report Exchanges is a direct connection or a bilateral relationship as illustrated below.

        ______________                     _____________
        |            |                     |           |
        |  GRC-RE    |_____________________|  GRC-RE   |
        |____________|                     |___________|

Figure 1: Direct Peer Topology

A star topology may be desirable in instances where a peer may be a provider of GRC Reports. This requires trust relationships to be established between the provider of information and each of the consumers of that information. Examples may include clients that file compliance or business reports to an authoritative entity.

The examples provided serve as an initial baseline set of expected topologies that may change over time.

3.3. Message Formats

Section 6 describes the five GRC Report Exchange message types, to be used with the appropriate XML documents. The messages are expected to be generated and received on designated systems for GRC report exchanges.

3.4. GRC Report Exchange Data Types

3.4.1. Boolean

A boolean value is represented by the BOOLEAN data type.

The BOOLEAN data type is implemented as "xs:boolean" [W3C.REC-xmlschema-1-20041028] in the schema.

3.4.2. Language

A language value is represented by the LANG data type.

The LANG data type is a valid language code per [RFC5646] constrained by the definition of "xs:language" [W3C.REC-xmlschema-1-20041028] inherited from [W3C.REC-xml-20081126].

3.4.3. Multilingual Strings

STRING data that represents multi-character attributes in a language different than the default encoding of the document is of the ML_STRING data type.

The ML_STRING data type is implemented as an "grc-exchange:MLStringType" in the schema.

The base definition of this type is reused from the IODEF specification [RFC5070], Section 2.4. This definition is fully included in the GRC-Exchange specification in Section 4.8 to prevent the need to use the IODEF schema.

3.4.4. Uniform Resource Locator strings

A uniform resource locator (URL) is represented by the URL data type. The format of the URL data type is documented in [RFC3986].

The URL data type is implemented as an "xs:anyURI" [W3C.REC-xmlschema-1-20041028] in the schema.

3.4.5. Date-Time Strings

Date-time strings are represented by the DATETIME data type. Each date-time string identifies a particular instant in time; ranges are not supported.

Date-time strings are formatted according to a subset of ISO 8601:2004 [ISO.8601.2000] documented in [RFC3339].

The DATETIME data type is implemented as an "xs:dateTime" [W3C.REC-xmlschema-1-20041028] in the schema.

The base definition of this type is reused from the IODEF specification [RFC5070], Section 2.8. This definition is fully included in the GRC-Exchange specification in Section 4.8 to prevent the need to use the IODEF schema.

3.4.6. Timezone String

A timezone offset from UTC is represented by the TIMEZONE data type. It is formatted according to the following regular expression: "Z|[\+\-](0[0-9]|1[0-4]):[0-5][0-9]".

The TIMEZONE data type is implemented as an "xs:string" [W3C.REC-xmlschema-1-20041028] with a regular expression constraint in the schema. This regular expression is identical to the timezone representation implemented in an "xs:dateTime".

The base definition of this type is reused from the IODEF specification [RFC5070], Section 2.9. This definition is fully included in the GRC-Exchange specification in Section 4.8 to prevent the need to use the IODEF schema.

3.4.7. Postal Address

A postal address is represented by the POSTAL data type. This data type is an ML_STRING whose format is documented in Section 2.23 of [RFC4519]. It defines a postal address as a free-form multi-line string separated by the "$" character.

The POSTAL data type is implemented as an "xs:string" [W3C.REC-xmlschema-1-20041028] in the schema.

The base definition of this type is reused from the IODEF specification [RFC5070], Section 2.11. This definition is fully included in the GRC-Exchange specification in Section 4.8 to prevent the need to use the IODEF schema.

3.4.8. Telephone and Fax Numbers

A telephone or fax number is represented by the PHONE data type. The format of the PHONE data type is documented in Section 2.35 of [RFC4519].

The PHONE data type is implemented as an "xs:string" [W3C.REC-xmlschema-1-20041028] in the schema.

The base definition of this type is reused from the IODEF specification [RFC5070], Section 2.13. This definition is fully included in the GRC-Exchange specification in Section 4.8 to prevent the need to use the IODEF schema.

3.4.9. Email String

An email address is represented by the EMAIL data type. The format of the EMAIL data type is documented in Section 3.4.1 of [RFC5322].

The EMAIL data type is implemented as an "xs:string" [W3C.REC-xmlschema-1-20041028] in the schema.

The base definition of this type is reused from the IODEF specification [RFC5070], Section 2.14. This definition is fully included in the GRC-Exchange specification in Section 4.8 to prevent the need to use the IODEF schema.

3.5. GRC Report Exchange Message Types

The five GRC Report Exchange message types are as follows:

  1. Acknowledgement. This message is sent to the requestor of a report (Request) or in response to a Query to notify on the state of a request (approved, pending, not approved).
  2. Result. This message is sent to the requestor of a GRC report (Request) or in response to a Query. The Result may contain the full report requested or a section of the report as appropriate for the request in the Query.
  3. Request. This message type is used to request a specific type of GRC report. The Request MUST specify the XML schema and version for the requested report along with any other parameters required in the XML schema to generate the correct report.
  4. Report. This message is used to provide a GRC Report. The message can be considered a wrapper for any approved GRC schema used to format a report for submission.
  5. Query. This message is used to request information about a specific GRC report. The XML schema and version used MUST be specified along with any details required to provide the proper Report response. The response is provided through the Report message.

When an application receives a GRC Report Exchange message, it must be able to determine the type of message and parse it accordingly. The message type is specified in the GRCPolicy class. The GRCPolicy class may also be used by the transport protocol to facilitate the secure communication of the GRC Report Exchange.

4. GRC-Exchange Schema

There are three classes included in the GRC Report Exchange schema required to facilitate communications. The RequestStatus class is used to indicate the approval status of a report Request or Query; the GRCDocument class identifies the XML schema to be used by the provided or requested report; and the GRCPolicy class provides information on the agreed-upon policies and specifies the type of communication message being used.

The GRC Report Exchange schema acts as an envelope for the GRC XML schema to facilitate secure GRC report communications. The intent in maintaining a separate schema is for the flexibility of sending messages between participating entities. Since GRC Report Exchange is a separate schema that includes the appropriate GRC XML schema, the GRC Report Exchange information acts as an envelope, and then the GRCPolicy class can be easily extracted for use by the transport protocol.

The security requirements of sending GRC reports and associated information on finance, IT operations, legal, compliance, and security across the network include the use of confidentiality (encryption prior to the transport level), authentication (potentially multi-hop), integrity, and non-repudiation. GRCPolicy uses labels that correspond to policy and agreements to standardize on handling requirements such as encryption and sharing limitations. The GRCPolicy information should not be encrypted, hence GRC Report Exchange is maintained separate from the GRC XML schema used to send or request a report. This segregation enables flexibility for GRC Report Exchange to be used with any GRC XML schema and removes the need for decrypting and parsing the entire GRC Report and GRC Report Exchange document to determine how it should be handled at each entity communicating via GRC Report Exchange.

The purpose of the GRCPolicy class is to specify the message type for the receiving host, facilitate the policy needs of GRC Reports, and provide routing information in the form of an IP address of the destination entity accepting GRC Report Exchange messages.

The policy information and guidelines are discussed in Section Section 4.1. The policy is defined between GRC-Exchange peers and within or between consortiums. The GRCPolicy is meant to be a tool to facilitate the defined policies. This MUST be used in accordance with policy set between clients, peers, consortiums, and/or regions. Security, privacy, and confidentiality MUST be considered as specified in this document.

The GRC Report Exchange (GRC-Exchange) schema is defined as follows:

        +------------------+
        |   GRC-Exchange   |
        +------------------+
        | LANG lang        |<>---{0..1}----[ GRCPolicy      ]
        |                  |
        |                  |<>---{0..1}----[ RequestStatus  ]
        |                  |
        |                  |<>---{0..1}----[ GRCDocument    ]
        +------------------+

Figure 2: The GRC-Exchange Schema

The aggregate classes that constitute the GRC-Exchange schema in the grc-exchange namespace are as follows:

GRCPolicy

  • Zero or One. The GRCPolicy class is used by all message types to facilitate policy agreements between peers, consortiums, or federations, as well as to properly route messages.

RequestStatus

  • Zero or One. The RequestStatus class is used only in Acknowledgement messages to report back to the entity requesting a report or sending a report Query if the request is denied or remains in a pending state.

GRCDocument

  • Zero or One. The GRCDocument class is used in each of the message types to state the XML schema and version for the included XML report, XML report request, or response.

The GRC-Exchange class defines one attribute as follows:

lang

Each of the three listed classes may be the only class included in the GRC-Exchange class, hence the option for zero or one. In some cases, GRCPolicy MAY be the only class in the GRC-Exchange definition when used by the transport protocol [RFC6546], as that information should be as small as possible and may not be encrypted. The Acknowledgement message using the RequestStatus class MUST be able to stand alone without the need for an GRC XML document to facilitate the communication, limiting the data transported to the required elements per [RFC6546].

4.1. GRCPolicy Class

The GRCPolicy class facilitates the delivery of GRC Report Exchange messages.

       +--------------------------+
       | GRCPolicy                |
       +--------------------------+
       |                          |<>---{0..1}----[ ReportID     ]
       | ENUM restriction         |
       | STRING ext-restriction   |<>-------------[ Node         ]
       | ENUM MsgType             |
       | STRING ext-MsgType       |<>---{1..*}----[ PolicyRegion ]
       | ENUM MsgDestination      |
       | STRING ext-MsgDestination|
       |                          |
       +--------------------------+

Figure 3: The GRCPolicy Class

The aggregate elements that constitute the GRCPolicy class are as follows:

ReportID

  • Zero or one. Global reference pointing back to the ReportID defined in the GRC XML data model. The ReportID includes the domain name of the entity who creates the report, a report number, and an instance of that report number. The default report number is a date, where the requested report is the most recent report on or prior to the date specified. The format for the date SHALL be YYYYMMDD, where Y is the year, M is the month, and D is the day. The instance number is appended with a dash separating the values and is used in cases for which there may be multiple reports issued in a day. The format for the instance SHALL be HHMMSS, where H is the hour as specified in a 24hour range, M is the minute, S is the second provided in GMT. An alternate ID may be specified within the GRC XML schema for the specific report. This element has been derived from IODEF [RFC5070].

Node

  • One. The Node class is used to identify a host or network device, in this case to identify the system communicating GRC-Exchange messages. The base definition of this class is reused from the IODEF specification [RFC5070], Section 3.16. This definition is fully included in the GRC-Exchange specification in Section 4.8 to prevent the need to use the IODEF schema.

PolicyRegion

  • One or many. REQUIRED. The values for the attribute "region" are used to determine what policy area may require consideration before a trace can be approved. The PolicyRegion may include multiple selections from the attribute list in order to fit all possible policy considerations when crossing regions, consortiums, or networks.

  • region
    • One. ENUM.
      1. ClientToSP. An enterprise initiated the request to their service provider.
      2. SPToClient. An service provider passed a GRC request or report to a client or an enterprise based on requested services or service level agreements.
      3. IntraConsortium. GRC report information that should have no restrictions within the boundaries of a consortium with the agreed-upon use and abuse guidelines.
      4. PeerToPeer. GRC report information that should have no restrictions between two peers but may require further evaluation before continuance beyond that point with the agreed-upon use and abuse guidelines.
      5. BetweenConsortiums. GRC report information that should have no restrictions between consortiums that have established agreed-upon use and abuse guidelines.
      6. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

    • Additionally, there is an extension attribute to add new enumerated values:
      • ext-region. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

The GRCPolicy class has six attributes:

  • restriction
    • Optional. ENUM. This attribute indicates the disclosure guidelines to which the sender expects the recipient to adhere for the information represented in this class and its children. This guideline provides no security since there are no specified technical means to ensure that the recipient of the document handles the information as the sender requested.
    • The value of this attribute is logically inherited by the children of this class. That is to say, the disclosure rules applied to this class, also apply to its children.
    • It is possible to set a granular disclosure policy, since all of the high-level classes (i.e., children of the Incident class) have a restriction attribute. Therefore, a child can override the guidelines of a parent class, be it to restrict or relax the disclosure rules (e.g., a child has a weaker policy than an ancestor; or an ancestor has a weak policy, and the children selectively apply more rigid controls). The implicit value of the restriction attribute for a class that did not specify one can be found in the closest ancestor that did specify a value.
    • This attribute is defined as an enumerated value with a default value of "private". Note that the default value of the restriction attribute is only defined in the context of the GRCPolicy class. In other classes where this attribute is used, no default is specified.
    • This attribute is derived from IODEF [RFC5070] and is fully included within this schema.
      1. public. There are no restrictions placed in the information.
      2. need-to-know. The information may be shared with other parties that are involved in the incident as determined by the recipient of this document (e.g., multiple victim sites can be informed of each other).
      3. private. The information may not be shared.
      4. default. The information can be shared according to an information disclosure policy pre-arranged by the communicating parties.
      5. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-restriction
    • OPTIONAL. STRING. A means by which to extend the restriction attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • MsgType
    • REQUIRED. ENUM. The type of GRC-Exchange message sent. The five types of messages are described in Section 3.5 and can be noted as one of the five selections below.
      1. Acknowledgement. This message is sent to the initiating GRC-Exchange entity if a Request or Query has been denied or is pending.
      2. Result. This message provides the result of a Query.
      3. Request. The purpose of the Request is to request a report from an entity.
      4. Report. This message is used to provide a GRC XML report.
      5. Query. This message is used to request information either about a specific report or group of reports. The actual query is specified in the GRC XML Schema and is outside the scope of this specification.
      6. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-MsgType
    • OPTIONAL. STRING. A means by which to extend the MsgType attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • MsgDestination
    • REQUIRED. ENUM. The destination required at this level may either be the system accepting GRC report exchange requests or reports. The Node element lists the address of the host receiving the GRC-Exchange message.
      1. GRCSystem. The address listed in the Node element of the GRCPolicy class is the system communicating via GRC-Exchange that will receive the message.
      2. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-MsgDestination
    • OPTIONAL. STRING. A means by which to extend the MsgDestination attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

4.2. RequestStatus

The RequestStatus class is an aggregate class in the GRC-Exchange class.

                  +--------------------------------+
                  | RequestStatus                  |
                  +--------------------------------+
                  |                                |
                  | ENUM restriction               |
                  | STRING ext-restriction         |
                  | ENUM AuthorizationStatus       |
                  | STRING ext-AuthorizationStatus |
                  | ENUM Justification             |
                  | STRING ext-Justification       |
                  |                                |
                  +--------------------------------+

Figure 4: The RequestStatus Class

The RequestStatus class has six attributes:

  • restriction
    • OPTIONAL. ENUM. This attribute indicates the disclosure guidelines to which the sender expects the recipient to adhere. This guideline provides no real security since it is the choice of the recipient of the document to honor it. This attribute follows the same guidelines as "restriction" used in IODEF and is explained in the GRCPolicy Class description in Section 4.1.

  • ext-restriction
    • OPTIONAL. STRING. A means by which to extend the restriction attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • AuthorizationStatus
    • REQUIRED. ENUM. The listed values are used to provide a response to the requesting entity of the ReportRequest or ReportQuery.
      1. Approved. The request was approved and will be provided. The approved message MAY be sent if there will be a delay in providing the report, otherwise, the Report or Result MAY be provided without sending a Acknowledgement message.
      2. Denied. The request has been denied.
      3. Pending. Awaiting approval; a timeout period has been reached, which resulted in this Pending status and Acknowledgement message being generated.
      4. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-AuthorizationStatus
    • OPTIONAL. STRING. A means by which to extend the AuthorizationStatus attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • Justification
    • OPTIONAL. ENUM. Provides a reason for a Denied or Pending message.
      1. SystemResource. A resource issue exists on the systems that would be involved in the request.
      2. Authentication. The enveloped digital signature [RFC3275] failed to validate.
      3. AuthenticationOrigin. The detached digital signature for the original requestor on the RecordItem entry failed to validate.
      4. Encryption. Unable to decrypt the request.
      5. UnrecognizedFormat. The format of the provided document was unrecognized.
      6. CannotProcess. The document could not be processed. Reasons may include legal or policy decisions. Resolution may require communication outside of this protocol to resolve legal or policy issues. No further messages SHOULD be sent until resolved.
      7. Other. There were other reasons this request could not be processed.
      8. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-Justification-ext
    • OPTIONAL. STRING. A means by which to extend the Justification attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

4.3. GRCDocument

The GRCDocument class is an aggregate class in the GRC-Exchange class.

         +-------------------------+
         |      GRCDocument        |
         +-------------------------+
         |                         |<>---{1..*}----[ ReportType  ]
         |  ENUM Version           |
         |  STRING ext-Version     |<>---{0..1}----[ FromContact ]
         |  ENUM XMLSchemaID       |
         |  STRING ext-XMLSchemaID |<>---{0..1}----[ URL         ]
         |  ENUM restriction       |
         |  STRING ext-restriction |<>---{1}-------[ XMLDocument ]
         |                         |
         |                         |<>---{0..*}----[ Signature   ]
         |                         |
         |                         |
         +-------------------------+

Figure 5: The GRCDocument Class

The elements that constitute the GRCDocument class are as follows:

  • ReportType
    • One or many. REQUIRED. The values for the attribute "type" are meant to assist in determining if the included XML report or request is appropriate for the entity receiving the request or report message. Multiple values may be selected for this element; however, where possible, it should be restricted to one value that most accurately describes the report type.
    • type
      • One. ENUM.
        1. Filing. This ReportType is used when a GRC report is included for expected filing purposes. Examples may include the filing of a regulatory or business operations report to a regulatory body.
        2. Service Level Agreement. This option specifies the report type as a report on a service level agreement. This report may be sent from a service provide (SP) to a tenant or client or from a trust authority to a requesting entity. An SLA report may be associated with any report format (XML) associated with an SLA agreement, including but not limited to an IT or security report.
        3. Operational. An operational report may include any standard operating reports used within or between businesses or enterprises. This may be a routine business, IT operational, or other type of report.
        4. Compliance. A compliance report is specified when there is a specific compliance report format required (as specified by the schema used for the report). This type may be used for internal or external compliance report exchanges.
        5. Audit. The Audit report type is distinguished from a compliance report as the report contents may vary depending on the report or report request in the exchange. An audit report may take an approach of only providing the state of compliance or details of findings from an automated control review.
        6. RiskAssessment. A RiskAssessment report differs from the Compliance and Audit reports in that the report may prioritize risks as specified in the XML schema and may include GRC-XML risk ratings. A RiskAssessment may be provided for any GRC area or on the GRC program as specified by the GRCDocument.
        7. OfficialBusiness. This option MUST be used if the GRC information is requested by or affiliated with any government or other official business request. This could be used during an investigation for an eDiscovery, eWarrant, or other use case.
        8. Other. If this option is selected, a description of the request MUST be provided so that policy decisions can be made to proceed with the request or act upon the report. The information should be provided in the GRC-Exchange class meaning attribute.
        9. ext-value. An escape value used to extend this type. This value has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

    • ext-type
      • OPTIONAL. One. STRING. A means by which to extend the type attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • FromContact
    • Zero or more. Contact. Provides contact information for the parties responsible for a report provided in the GRC Report Exchange as defined by the Contact class in Section 4.6.

  • URL
    • Zero or One. URL. A reference to the XML schema included. The URL data type is defined in Section 3.4.4. The schemaLocation for IODEF is already included in the RID schema, so this is not necessary to include a URL for IODEF documents.

  • XMLDocument
    • One. ExtensionType. The XMLDocument is a complete XML document defined by the ExtensionType class in Section 4.7. This class follows the guidelines in [RFC5070] Section 5 where the data type is set to "xml" and meaning is set to "xml" to include an xml document.

  • Signature
    • Zero to many. ExtensionType. The Signature includes a complete XML document with the type specified by the ExtensionType class in Section 4.7. This class follows the guidelines in [RFC5070] Section 5 where the data type is set to "xml" and meaning is set to "xml" to include an xml document. The usage of this element is similar to RID [RFC6545] and is used to encapsulate the detached signature based on a specific class within the XML document to verify the originator of the message. If a detached signature is used, guidance for the encapsulated document MUST be provided as to which class should be used to create the signature. Alternatively, if no guidance is provided, the digital signature MUST be an enveloped signature of the entire XML document that is encapsulated. This attribute has been derived from RID [RFC6545], Section 5.1.1.

  • The GRCDocument class has six attributes:
  • Version
    • OPTIONAL. One. The Version attribute is the version number of the specified XML schema. That schema must be an approved version of a schema registered with IANA for use with GRC-Exchange. The IANA registry for managing schemas used with GRC-Exchange is specified in Section 13. This attribute has been derived from RID [RFC6545], Section 5.1.1.
      • ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-Version
    • OPTIONAL. One. STRING. The ext-Version attribute is the version number of the included XML schema. This attribute is used if a schema other than an IANA registered schema that has been added to the enumerated list for Version is included. This attribute has been derived from RID [RFC6545], Section 5.1.1.

  • XMLSchemaID
    • OPTIONAL. One. URL. The XMLSchemaID attribute is the identifier, the defined namespace [W3C.REC-xml-names-20091208], of the XML schema of the XML document included. The XMLSchemaID and Version specify the format of the XMLDocument element. The only permitted values, include any namespace listed in the IANA managed list of registered schemas for use with GRC-Exchange. The IANA registry for managing schemas is specified in Section 13. This attribute has been derived from RID [RFC6545], Section 5.1.1.
      • ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-XMLSchemaID
    • OPTIONAL. One. The ext-XMLSchemaID attribute is the identifier (defined namespace) of the XML schema of the XML document included. The ext-XMLSchemaID and ext-Version specify the format of the XMLDocument element and are used if the included schema is not an IANA registered schema that has been added to the enumerated list for XMLSchemaID. This attribute has been derived from RID [RFC6545], Section 5.1.1.

  • restriction
    • OPTIONAL. ENUM. This attribute indicates the disclosure guidelines to which the sender expects the recipient to adhere. This guideline provides no real security since it is the choice of the recipient of the document to honor it. This attribute follows the same guidelines as "restriction" used in IODEF and is explained in the GRCPolicy Class description in Section 4.1.

  • ext-restriction
    • OPTIONAL. STRING. A means by which to extend the restriction attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

4.4. Reference Class

The Reference class is a reference to the GRC Schema used for the exchange. A reference consists of a name, a URL to this reference, and an optional description.

        +------------------+
        | Reference        |
        +------------------+
        |                  |<>----------[ ReferenceName ]
        |                  |<>--{0..*}--[ URL           ]
        |                  |<>--{0..*}--[ Description   ]
        +------------------+

Figure 6: The Reference Class

The aggregate classes that constitute Reference:

  • ReferenceName
    • One. ML_STRING. Name of the reference.

  • URL
    • Zero or many. URL. A URL associated with the reference.

  • Description
    • Zero or many. ML_STRING. A free-form text description of this reference.

4.5. ReportID Class

The ReportID class represents a report tracking number that is unique in the context of the reporting organization and identifies the activity characterized in a GRCDocument. This identifier would serve as an index into the organizational reporting system. The combination of the name attribute and the string in the element content MUST be a globally unique identifier describing the activity. Documents generated by a given organization MUST NOT reuse the same value unless they are referencing the same report instance. The ReportID class is derived from IODEF [RFC5070], Section 3.3.

     +------------------------+
     | ReportID               |
     +------------------------+
     | STRING                 |
     |                        |
     | STRING name            |
     | STRING instance        |
     | ENUM restriction       |
     | STRING ext-restriction |
     +------------------------+

Figure 7: The ReportID Class

The ReportID class has four attributes:

  • name
    • Required. STRING. An identifier describing the organization that created the report. In order to have a globally unique organization name, the fully qualified domain name associated with the organization MUST be used.

  • instance
    • Optional. STRING. An identifier referencing a subset of the named report.

  • restriction
    • Optional. ENUM. This attribute follows the same guidelines as "restriction" explained in the GRCPolicy Class description in Section 4.1.

  • ext-restriction
    • OPTIONAL. STRING. A means by which to extend the restriction attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

4.6. Contact Class

The Contact class describes contact information for organizations and personnel involved in the report exchange. This class allows for the naming of the involved party, specifying contact information for them, and identifying their role in the XML Report. The Contact class is derived from IODEF [RFC5070], Section 3.7.

People and organizations are treated interchangeably as contacts; one can be associated with the other using the recursive definition of the class (the Contact class is aggregated into the Contact class). The 'type' attribute disambiguates the type of contact information being provided.

The inheriting definition of Contact provides a way to relate information without requiring the explicit use of identifiers in the classes or duplication of data. A complete point of contact is derived by a particular traversal from the root Contact class to the leaf Contact class. As such, multiple points of contact might be specified in a single instance of a Contact class. Each child Contact class logically inherits contact information from its ancestors.

  +------------------------+
  | Contact                |
  +------------------------+
  | ENUM role              |<>-{0..1}-[ ContactName       ]
  | STRING ext-role        |<>-{0..*}-[ Description       ]
  | ENUM type              |<>-{0..*}-[ RegistryHandle    ]
  | STRING ext-type        |<>-{0..1}-[ PostalAddress     ]
  | ENUM restriction       |<>-{0..*}-[ Email             ]
  | STRING ext-restriction |<>-{0..*}-[ Telephone         ]
  |                        |<>-{0..1}-[ Fax               ]
  |                        |<>-{0..1}-[ Timezone          ]
  |                        |<>-{0..*}-[ AdditionalContact ]
  |                        |<>-{0..*}-[ AdditionalData    ]
  +------------------------+

Figure 8: The Contact Class

The aggregate classes that constitute the Contact class are:

  • ContactName
    • Zero or one. ML_STRING. The name of the contact. The contact may either be an organization or a person. The type attribute disambiguates the semantics.

  • Description
    • Zero or many. ML_STRING. A free-form description of this contact. In the case of a person, this is often the organizational title of the individual.

  • RegistryHandle
    • Zero or many. A handle name into the registry of the contact.

  • PostalAddress
    • Zero or one. The postal address of the contact.

  • Email
    • Zero or many. The email address of the contact.

  • Telephone
    • Zero or many. The telephone number of the contact.

  • Fax
    • Zero or one. The facsimile telephone number of the contact.

  • Timezone
    • Zero or one. TIMEZONE. The timezone in which the contact resides formatted according to Section Section 3.4.6.

  • AdditionalContact
    • Zero or many. A Contact instance contained within another Contact instance inherits the values of the parent(s). This recursive definition can be used to group common data pertaining to multiple points of contact and is especially useful when listing multiple contacts at the same organization.

  • AdditionalData
    • Zero or many. A mechanism by which to extend the data model.

At least one of the aggregate classes MUST be present in an instance of the Contact class. This is not enforced in the GRC-Exchange schema as there is no simple way to accomplish it.

The Contact class has six attributes:

  • role
    • Required. ENUM. Indicates the role the contact fulfills. This attribute is defined as an enumerated list:
      1. creator. The entity that generate the document.
      2. admin. An administrative contact for a host, network, or entity.
      3. tech. A technical contact for a host or network.
      4. cc. (also known as carbon-copy) An entity that is to be kept informed about the report.
      5. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-role
    • Optional. STRING. A means by which to extend the role attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • type
    • Required. ENUM. Indicates the type of contact being described. This attribute is defined as an enumerated list:
      1. person. The information for this contact references an individual.
      2. organization. The information for this contact references an organization.
      3. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-type
    • Optional. STRING. A means by which to extend the type attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • restriction
    • Optional. ENUM. This attribute follows the same guidelines as "restriction" used in IODEF and is explained in the GRCPolicy Class description in Section 4.1.

  • ext-restriction
    • OPTIONAL. STRING. A means by which to extend the restriction attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

This definition is from the IODEF specification [RFC5070], Section 3.7. This definition is fully included in the GRC-Exchange specification to prevent the need to use the IODEF schema.

4.6.1. RegistryHandle Class

The RegistryHandle class represents a handle into an Internet registry or community-specific database. The handle is specified in the element content and the type attribute specifies the database. The RegistryHandle class is derived from IODEF [RFC5070], Section 3.7.1.

    +---------------------+
    | RegistryHandle      |
    +---------------------+
    | STRING              |
    |                     |
    | ENUM registry       |
    | STRING ext-registry |
    +---------------------+

Figure 9: The RegistryHandle Class

The RegistryHandle class has two attributes:

  • registry
    • Required. ENUM. The database to which the handle belongs. The default value is 'local'. The possible values are:
      1. internic. Internet Network Information Center
      2. apnic. Asia Pacific Network Information Center
      3. arin. American Registry for Internet Numbers
      4. lacnic. Latin-American and Caribbean IP Address Registry
      5. ripe. Reseaux IP Europeens
      6. afrinic. African Internet Numbers Registry
      7. local. A database local to the CSIRT
      8. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-registry
    • Optional. STRING. A means by which to extend the registry attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

This definition is from the IODEF specification [RFC5070], Section 3.7.1. This definition is fully included in the GRC-Exchange specification to prevent the need to use the IODEF schema.

4.6.2. PostalAddress Class

The PostalAddress class specifies a postal address formatted according to the POSTAL data type (Section 3.4.7).

    +---------------------+
    | PostalAddress       |
    +---------------------+
    | POSTAL              |
    |                     |
    | ENUM meaning        |
    | ENUM lang           |
    +---------------------+

Figure 10: The PostalAddress Class

The PostalAddress class has two attributes:

This definition is from the IODEF specification [RFC5070], Section 3.7.2. This definition is fully included in the GRC-Exchange specification to prevent the need to use the IODEF schema.

4.6.3. Email Class

The Email class specifies an email address formatted according to EMAIL data type (Section 3.4.9).

    +--------------+
    | Email        |
    +--------------+
    | EMAIL        |
    |              |
    | ENUM meaning |
    +--------------+

Figure 11: The Email Class

The Email class has one attribute:

  • meaning
    • Optional. ENUM. A free-form description of the element content.

This definition is from the IODEF specification [RFC5070], Section 3.7.3. This definition is fully included in the GRC-Exchange specification to prevent the need to use the IODEF schema.

4.6.4. Telephone and Fax Classes

The Telephone and Fax classes specify a voice or fax telephone number respectively, and are formatted according to PHONE data type (Section 3.4.8).

    +--------------------+
    | {Telephone | Fax } |
    +--------------------+
    | PHONE              |
    |                    |
    | ENUM meaning       |
    +--------------------+

Figure 12: The Telephone and Fax Classes

The Telephone class has one attribute:

  • meaning
    • Optional. ENUM. A free-form description of the element content (e.g., hours of coverage for a given number).

This definition is from the IODEF specification [RFC5070], Section 3.7.4. This definition is fully included in the GRC-Exchange specification to prevent the need to use the IODEF schema.

4.7. ExtensionType Class

The ExtensionType class serves as an extension mechanism for information not otherwise represented in the data model. For relatively simple information, atomic data types (e.g., integers, strings) are provided with a mechanism to annotate their meaning. The class can to encapsulating entire XML documents conforming to an IANA registered Schema. This class is also used to provide a consistent location for the inclusion of digital signatures.

Unlike XML, which is self-describing, atomic data must be documented to convey its meaning. This information is described in the 'meaning' attribute. Since these description are outside the scope of the specification, some additional coordination may be required to ensure that a recipient of a document using the ExtensionType classes can make sense of the custom extensions.

    +------------------+
    | AdditionalData   |
    +------------------+
    | ANY              |
    |                  |
    | ENUM dtype       |
    | STRING ext-dtype |
    | STRING meaning   |
    | STRING formatid  |
    | ENUM restriction |
    +------------------+

Figure 13: The ExtensionType Class

The ExtensionType class has five attributes:

  • dtype
    • Required. ENUM. The data type of the element content. The permitted values for this attribute are shown below. The default value is "string".
      1. boolean. The element content is of type BOOLEAN.
      2. byte. The element content is of type BYTE.
      3. character. The element content is of type CHARACTER.
      4. date-time. The element content is of type DATETIME.
      5. integer. The element content is of type INTEGER.
      6. portlist. The element content is of type PORTLIST.
      7. real. The element content is of type REAL.
      8. string. The element content is of type STRING.
      9. file. The element content is a base64 encoded binary file encoded as a BYTE[] type.
      10. frame. The element content is a layer-2 frame encoded as a HEXBIN type.
      11. packet. The element content is a layer-3 packet encoded as a HEXBIN type.
      12. ipv4-packet. The element content is an IPv4 packet encoded as a HEXBIN type.
      13. ipv6-packet. The element content is an IPv6 packet encoded as a HEXBIN type.
      14. path. The element content is a file-system path encoded as a STRING type.
      15. url. The element content is of type URL.
      16. csv. The element content is a common separated value (CSV) list per Section 2 of [RFC4180] encoded as a STRING type.
      17. winreg. The element content is a Windows registry key encoded as a STRING type.
      18. xml. The element content is XML (see Section 5).
      19. ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-dtype
    • Optional. STRING. A means by which to extend the dtype attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • meaning
    • Optional. STRING. A free-form description of the element content.

  • formatid
    • Optional. STRING. An identifier referencing the format and semantics of the element content.

  • restriction
    • Optional. ENUM. This attribute follows the same guidelines as "restriction" explained in the GRCPolicy Class description in Section 4.1.

This definition is from the IODEF specification [RFC5070], Section 3.6. This definition is fully included in the GRC-Exchange specification to prevent the need to use the IODEF schema.

4.8. Node Class

The Node class names a system (e.g., PC, router) or network.

This class was derived from IODEF [RFC5070] and is partially included in this specification. The original IODEF definition was derived from IDMEF [RFC4765].

   +---------------+
   | Node          |
   +---------------+
   |               |<>--{0..*}--[ NodeName ]
   |               |<>--{0..*}--[ Address  ]
   |               |<>--{0..1}--[ Location ]
   |               |<>--{0..1}--[ DateTime ]
   +---------------+

Figure 14: The Node Class

The aggregate classes that constitute Node are:

  • NodeName
    • Zero or more. ML_STRING. The name of the Node (e.g., fully qualified domain name). This information MUST be provided if no Address information is given.

  • Address
    • Zero or more. The hardware, network, or application address of the Node. If a NodeName is not provided, at least one Address MUST be specified. This class is defined in Section 4.9.

  • Location
    • Zero or one. ML_STRING. A free-from description of the physical location of the equipment.

  • DateTime
    • Zero or one. DATETIME. A timestamp of when the resolution between the name and address was performed. This information SHOULD be provided if both an Address and NodeName are specified.

4.9. Address Class

The Address class represents a hardware (layer-2), network (layer-3), or application (layer-7) address.

This class was derived from IODEF [RFC5070] and is fully included in this specification. The original IODEF definition was derived from IDMEF [RFC4765].

   +---------------------+
   | Address             |
   +---------------------+
   | ENUM category       |
   | STRING ext-category |
   | STRING vlan-name    |
   | INTEGER vlan-num    |
   +---------------------+

Figure 15: The Address Class

The Address class has four attributes:

  • category
    • Required. ENUM. The type of address represented. The permitted values for this attribute are shown below. The default value is "ipv4-addr".
      • asn. Autonomous System Number
      • atm. Asynchronous Transfer Mode (ATM) address
      • e-mail. Electronic mail address (RFC 822)
      • ipv4-addr. IPv4 host address in dotted-decimal notation (a.b.c.d)
      • ipv4-net. IPv4 network address in dotted-decimal notation, slash, significant bits (a.b.c.d/nn)
      • ipv4-net-mask. IPv4 network address in dotted-decimal notation, slash, network mask in dotted-decimal notation (a.b.c.d/w.x.y.z)
      • ipv6-addr. IPv6 host address
      • ipv6-net. IPv6 network address, slash, significant bits
      • ipv6-net-mask. IPv6 network address, slash, network mask
      • mac. Media Access Control (MAC) address
      • ext-value. An escape value used to extend this attribute. This attribute has been derived from IODEF [RFC5070], Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • ext-category
    • Optional. STRING. A means by which to extend the category attribute. This attribute has been derived from IODEF [RFC5070] Section 5.1 and is explained in Section 5, Extending the Enumerated Values of Attributes.

  • vlan-name
    • Optional. STRING. The name of the Virtual LAN to which the address belongs.

  • vlan-num
    • Optional. STRING. The number of the Virtual LAN to which the address belongs.

4.10. GRC-Exchange Name Spaces

The GRC-Exchange schema declares a namespace of "grc-exchange-1.0" and registers it per [W3C.REC-xml-names-20091208]. Any XML instance incorporating GRC-Exchange MUST use the element GRC-Exchange in the "urn:ietf:params:xml:ns:grc-exchange-1.0" namespace. It can be referenced as follows:

<GRC-Exchange version="1.00" lang="en-US"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-Instance"
   xmlns:grc-exchange="urn:ietf:params:xml:ns:grc-exchange-1.0"
   xsi:schemaLocation="http://www.iana.org/assignments/xml-registry/schema
   /grc-exchange-1.0.xsd">

5. Extending the Enumerated Values of Attributes

In order to support the evolving needs of XML Schema exchanges, some extensibility is built into the GRC Report Exchange protocol. This section discusses how new attributes that have no current representation in the data model can be incorporated into GRC-Exchange. These techniques are designed so that adding new data will not require a change to the schema. With proven value, well-documented additions can be incorporated into future versions of the specification. However, this approach also supports private additions relevant only to a closed consortium.

The data model supports a means by which to add new enumerated values to an attribute, following the method used in IODEF [RFC5070] for the same purpose. For each attribute that supports this extension technique, there is a corresponding attribute in the same element whose name is identical, less a prefix of "ext-". This special attribute is referred to as the extension attribute, and the attribute being extended is referred to as an extensible attribute. For example, an extensible attribute named "foo" will have a corresponding extension attribute named "ext-foo". An element may have many extensible, and therefore many extension, attributes. In addition to a corresponding extension attribute, each extensible attribute has "ext-value" as one its possible values. This particular value serves as an escape sequence and has no valid meaning.

In order to add a new enumerated value to an extensible attribute, the value of this attribute MUST be set to "ext-value", and the new desired value MUST be set in the corresponding extension attribute. For example, an extended instance of the type attribute of the Impact class would look as follows:

    <Impact type="ext-value" ext-type="new-attack-type">

A given extension attribute MUST NOT be set unless the corresponding extensible attribute has been set to "ext-value".

6. GRC Report Exchange Messages

The GRC-Exchange schema is used in combination with GRC XML documents to facilitate GRC Report Exchange communications. Each message type varies slightly in format and purpose; hence, the requirements vary and are specified for each.

Note: The implementation of GRC-Exchange may automate the ability to fill in the content required for each message type from the GRC management systems involved in the message exchange.

6.1. Acknowledgement

Description: This message is sent in response to a Request or a Query message to provide status as to the approval of a request.

The following information is required for Acknowledgement messages and is provided through:

GRC-Exchange Information:

  • GRCPolicy
    • GRC-Exchange message type, ReportID, and destination policy information

  • RequestStatus class:
    • AuthorizationStatus of request

Standards for encryption and digital signatures [RFC3275], [W3C.REC-xmldsig-core-20080610]:

  • Digital signature of responding entity authenticity of GRC-Exchange Message, from the entity creating this message using an enveloped XML digital signature.
  • XML encryption as required by policy, agreements, and standard data markers.

A pending status is automatically generated after a 5-minute timeout without system predefined or administrator action taken to approve or deny the request. If a request is left in a pending state for more than a configurable period of time (default of 5 minutes), a response is sent to the requestor with the enumeration value set to pending. If a request is denied, the response sets the enumeration value to denied. If the request is approved, but the response will be delayed, a response MAY be sent with the enumerated value set to approved. The approved message is not mandatory, however the pending and denied message types MUST be sent if the conditions are reached.

6.2. Result

Description: This message provides the result of an approved Query. The Query may be used when a query is made on a group of reports or a request is made for specific details within a report. If a standard report is requested based on a specific XML schema, Request MUST be used. The details of the Query will vary depending on the included GRC XML schema. The XML schema may provide specific guidance on how queries are conducted as this specification is intended to provide a generalized structure for many types of GRC information exchanges.

The following information is required for Result messages and will be provided through:

  • GRC-Exchange Information:
    • GRCPolicy
      • GRC-Exchange message type, ReportID, and destination policy information

    • GRCDocument
      • The GRCDocument class specifies the specific GRC-Exchange XML schema that is required per the Query. The Result will include the necessary information to appropriately respond to the request.

  • GRC XML Information:
    • GRC XML schema elements and attributes as appropriate for the Query.

  • Standards for encryption and digital signatures [RFC3275]:
    • Digital signature of sending entity for authenticity of Result message, from the entity creating this message using an enveloped XML digital signature.
    • XML encryption as required by policy, agreements, and standard data markers.

A Result message is sent back to the requesting entity of a Query. This will include the results of the query using the appropriate XML schema named in the request. Details of what standard queries are automated in addition to the standard responses are to be detailed by the appropriate GRC communities (GRC-XML, LI-XML, etc.) in guidance documents associated with each of the relevant schemas.

6.3. Request

Description: The Request is used to request a report in a standardized format using the referenced XML schema in the GRCDocument class. The report requested will be the most recent report to the date and time requested.

The following information is required for Request messages and is provided through:

  • GRC-Exchange Information:
    • GRCPolicy
      • GRC-Exchange message type, ReportID, and destination policy information

  • GRC XML Information:
    • GRC XML schema elements and attributes as appropriate for the Request.

  • Standards for encryption and digital signatures [RFC3275]:
    • Digital signature from initiating entity sending the GRC-Exchange message using a detached XML digital signature on the GRC-Exchange information.
    • Digital signature of requesting entity for authenticity of the GRC-Exchange message, from the entity sending this message using an enveloped XML digital signature on the included GRC-XML document document.
    • XML encryption as required by policy, agreements, and data markers.

Security requirements include the ability to encrypt [W3C.REC-xmlenc-core-20021210] the contents of the ReportRequest message using the public key of the destination entity communicating via GCR-Exchange. If no report is available for the exact date and time in the request, the most recent report details prior to the date requested will be provided. If there is no report to provide per the specified date and time, the Acknowledgement message will be sent instead setting the AuthorizationStatus to denied and providing the appropriate reason for the deny.

6.4. Report

Description: This message is used to provide a report using a specified GRC XML schema. This message does not require any actions to be taken, except to file the report on the receiving system or associated database. This message may be in response to a Request or sent as a regularly scheduled report.

The following information is required for Report messages and will be provided through:

  • GRC-Exchange Information:
    • GRCPolicy GRC-Exchange message type, ReportID, and destination policy information

  • The following data is recommended if available and can be provided through:
  • GRC XML Information:
    • GRC XML schema elements and attributes as appropriate for the Request.

  • Standards for encryption and digital signatures [RFC3275]:
    • Digital signature from initiating entity, passed to all systems receiving the report using an enveloped XML digital signature.
    • XML encryption as required by policy, agreements, and standard data markers.

Security requirements include the ability to encrypt [W3C.REC-xmlenc-core-20021210] the contents of the Report message using the public key of the destination entity. Senders of a Report message should note that the information may be used to correlate information for the purpose of trending, pattern detection, etc., and may be shared with other parties unless otherwise agreed upon with the receiving entity in an established contract or agreement. Therefore, sending parties of a Report message may obfuscate or remove sensitive information before sending a Report message. A Report message may be sent either to file a report or in response to an ReportRequest, and data sensitivity must be considered in both cases.

6.5. Query

Description: The report Query message is used to request information from a trusted entity participating in GRC-Exchanges. The request can include the ReportID number, if known, or detailed information about the report or group of reports applicable to the query.

The following information must be used for a report Query message and is provided through:

  • GRC-Exchange Information:
    • GRCPolicy
      • GRC-Exchange message type, ReportID, and destination policy information

  • GRC XML information (optional):
    • GRC XML schema elements and attributes as appropriate for the report Query.

  • Standards for encryption and digital signatures [RFC3275]:
    • Digital signature from the entity initiating the GRC-Exchange message, passed to all systems receiving the report Query using an enveloped XML digital signature.
    • XML encryption as required by policy, agreements, and standard data markers.

The proper response to the Query message is a Result message. Security requirements include the ability to encrypt [W3C.REC-xmlenc-core-20021210] the contents of the report Request message using the public key of the destination entity communicating via GCR-Exchange. If no report is available for the exact date and time in the request, the most recent report details prior to the date requested will be provided. If there is no report to provide per the specified date and time, the Acknowledgement message will be sent instead setting the AuthorizationStatus to denied and providing the appropriate reason for the deny.

7. GRC-Exchange Communication Flows

The following section outlines the communication flows for GRC-Exchange and also provides examples of messages.

7.1. Report Communication Flow

The diagram below outlines the communication flow for a GRC-Exchange Report message sent from one entity to another. This communication flow is the simplest as no response is required. The Report may be a regularly scheduled report filing.

     Sending Entity                    Receiving Entity

     1. Generate Report message

     2.        o----------Report---------->

     3.                                Receive and process report
                                       No Response

Figure 16: GRC-Exchange Report Communication Flow

The Report message MAY be encrypted [W3C.REC-xmlenc-core-20021210] for the recipient of the report depending upon the markers included in the restriction class either in the GRC-Exchange schema or in the GRC XML schema used for the report. When a report is received, the receiving entity must verify that the report has not already been filed. The ReportID and other distinguishing information in the specific report type can be used to compare with existing database entries. The Report message typically does not have a response, but the use of an Acknowledgement message is sometimes required to communicate status or error handling information.

7.1.1. GRC-Exchange Report Example

The example listed is of a Report based on ...

In the following example, use of [W3C.REC-xmldsig-core-20080610] to generate digital signatures follows the guidance of XMLDsig 1.0 [W3C.REC-xmldsig-core-20080610]. XMLDsig version 1.1 [W3C.CR-xmldsig-core1-20110303] supports additional digest algorithms. Reference [RFC4051] for URIs intended for use with XML digital signatures, encryption, and canonicalization. SHA-1 SHOULD NOT be used, see [RFC6194] for further details.


Example to be provided in an updated version of this document.

7.2. Request Communication Flow

The diagram below outlines the GRC-Exchange report request communication flow between participating entities. The proper response to a report Request is a Report message. If there is a problem with the request, such as a failure to validate the digital signature or decrypt the request, a Acknowledgement message is sent to the requestor. The Acknowledgement message should provide the reason why the message could not be processed.

     Sending Entity                    Receiving Entity

     1. Generate report Request

     2.          o--------Request---------->

     3.                                Receive and process request 

     4.                                If denied or pending, send notice
                                       
     5.         <---Acknowledgement---o

     6.                                If request is approved,

     7.         <----------Report----------o

Figure 17: Request Communication Flow

7.2.1. Request Example

The following example of the report Request is based on the ReportID time-based identifier tied to the specified GRC XML GRCDocument.


Example to be provided in an updated version of this document.

7.2.2. Acknowledgement Message Example

The example Acknowledgement message is in response to the report Request listed above. The entity that received the request was unable to validate the digital signature used to authenticate the sending RID system.


Example to be provided in an updated version of this document.

7.3. Query Communication Flow

The diagram below outlines the GRC-Exchange report Query communication flow between participating entities.

     Sending Entity                    Receiving Entity

     1. Generate Report Query

     2.          o---------Query----------->

     3.                                Receive and process request 

     4.                                If denied or pending, send notice
                                       
     5.         <---Acknowledgement---o

     6.                                If request approved

     7.         <----------Result----------o


Figure 18: Query Communication Flow

The report Query communication flow is used to request specific information about a GRC report or group of reports. Information may be shared between participating entities using this format.

If there is a problem with the Query message, such as a failure to validate the digital signature [RFC3275] or decrypt the request, an Acknowledgement message is sent to the requestor. The Acknowledgement message should provide the reason why the message could not be processed.

7.3.1. Query Example

The following example includes the GRC-Exchange information and an example query using an included XML schema, which is also referenced in the GRCDocument class.


Example to be provided in an updated version of this document.

7.3.2. Acknowledgement Message Example

The example Acknowledgement message is in response to the Query message listed above. The entity that received the request is responding with an answer to the Query. The Result in this instance will be delayed for more than the 5-minute default time period, hence a Acknowledgement message is sent to notify of the approval status.


Example to be provided in an updated version of this document.

7.3.3. Result Message Example

The example Result message is in response to the Query request. This message type may be preceded by a Acknowledgement within the report Query flow of messages. It may be a direct response to a report Query request if the request is approved prior to the timeout period. This message provides a response to the request in the Query.


Example to be provided in an updated version of this document.

8. Internationalization Issues

Internationalization and localization is of specific concern to the GRC-Exchange, since information will often need to be exchanged across language barriers. The GRC-Exchange supports this goal by depending on XML constructs, and through explicit design choices in the data model.

GRC-Exchange documents are limited to the use of UTF-8 as it adequately provides the necessary support for internationalization. Additionally, each included document MUST specify the language in which their contents are encoded. The language can be specified with the attribute "xml:lang" (per Section 2.12 of [W3C.REC-xml-20081126]) in the top-level element (i.e., GRC-Exchange-Document@lang) and letting all other elements inherit that definition. All GRC-Exchange classes with a free-form text definition (i.e., all those defined of type grc-exchange:MLStringType) can also specify a language different from the rest of the document. The valid language codes for the "xml:lang" attribute are described in [RFC5646].

The data model supports multiple translations of free-form text. In the places where free-text is used for descriptive purposes, the given class always has a one-to-many cardinality to its parent (e.g., Description class). The intent is to allow the identical text to be encoded in different instances of the same class, but each being in a different language. This approach allows a GRC-Exchange document author to send recipients speaking different languages an identical document. The GRC-Exchange parser SHOULD extract the appropriate language relevant to the recipient.

While the intent of the data model is to provide internationalization and localization, the intent is not to do so at the detriment of interoperability. While the GRC-Exchange does support different languages, the data model also relies heavily on standardized enumerated attributes that can crudely approximate the contents of the document. With this approach, an organization should be able to make some sense of an GRC-Exchange document it receives even if the text based data elements are written in a language unfamiliar to the consumer.

The Node class identifies a host or network device. This document re-uses the definition of Node from the IODEF specification [RFC5070], Section 3.16. However, that document did not clearly specify whether a NodeName could be an Internationalized Domain Name (IDN). GRC-Exchange systems MUST treat the NodeName class as a domain name slot [RFC5890]. GRC-Exchange systems SHOULD support IDNs in the NodeName class; if they do so, the UTF-8 representation of the domain name MUST be used, i.e., all of the domain name's labels MUST be U-labels expressed in UTF-8 or NR-LDH labels [RFC5890]; A-labels MUST NOT be used. An application communicating via GRC-Exchange can convert between A-labels and U-labels by using the Punycode encoding [RFC3492] for A-labels as described in the protocol specification for Internationalized Domain Names in Applications [RFC5891].

9. GRC-Exchange Schema Definition

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:grc-xml="urn:ietf:params:xml:ns:grc-xml-1.0"
 xmlns:xs="http://www.w3.org/2001/XMLSchema"
 xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
 targetNamespace="urn:ietf:params:xml:ns:grc-xml-1.0"
 elementFormDefault="qualified" attributeFormDefault="unqualified">

<xs:import namespace="http://www.w3.org/2000/09/xmldsig#"
 schemaLocation=
 "http://www.w3.org/TR/xmldsig-core/xmldsig-core-schema.xsd"/>

<!-- ****************************************************************
*********************************************************************
***     GRC Report Exchange - GRC-Exchange                        ***
***     Namespace - grc-exchange, October 2011                    ***
***     The namespace is defined to support transport of XML      ***
***     documents for exchanging GRC information.                 ***
*********************************************************************
-->
<!--GRC-Exchange acts as an envelope for XML documents to support the
    exchange of messages-->
<!--
======          GRC Report Exchange          ======
====  Suggested definition for GRC messaging ======
 -->


***  Schema to be included here  ***


10. Requirements for GRC XML Schemas for GRC-Exchange

GRC Report Exchange is a generalized version of the Real-time Inter-network Defense (RID) [RFC6545] protocol. RID leverages certain aspects of the Incident Object Description Exchange Format (IODEF) [RFC5070] schema to provide the necessary security features such as confidentiality and integrity required for the exchange of potentially sensitive information. In generalizing RID into a schema and set of message exchange flows for GRC reports, the GRC XML schemas MUST include the following: classes, elements, and attributes with enumerated values to facilitate the automated security and confidentially concerns for GRC Report Exchange. A GRC XML schema within this document may refer to any type of XML schema used for Governance, Risk, and Compliance information or reporting. Examples include, but are not limited to GRC-XML, LI-XML, and security automation XML schemas.

  • The restriction attribute, reused from IODEF [RFC5070] into GRC-Exchange, MUST be included in any individual class of a GRC XML schema that could require XML encryption [W3C.REC-xmlenc-core-20021210] just on the data contained in that class. If encryption is only required at the full document level based on the sensitivity and sharing requirements, the restriction attribute in GRC-Exchange may be sufficient.

11. Security Requirements

The content in this section is derived from RID [RFC6545].

11.1. XML Digital Signatures and Encryption

GRC-Exchange leverages existing security standards and data markings in GRCPolicy to achieve the required levels of security for the exchange of GRC information. The use of standards include TLS and the XML security features of encryption [W3C.REC-xmlenc-core-20021210] and digital signatures [RFC3275], [W3C.REC-xmldsig-core-20080610]. The standards provide clear methods to ensure that messages are secure, authenticated, and authorized, and that the messages meet policy and privacy guidelines and maintain integrity.

As specified in the relevant sections of this document, the XML digital signature [RFC3275] and XML encryption [W3C.REC-xmlenc-core-20021210] are used in the following cases:

XML Digital Signature

  • For all message types, the full GRC-Exchange document MUST be signed using an enveloped signature by the sending peer to provide authentication and integrity to the receiving GRC-Exchange system. The signature is placed in an instance of the Signature element.
  • XML Signature Best Practices [W3C.WD-xmldsig-bestpractices-20110809] guidance SHOULD be followed to prevent or mitigate security risks. Examples include the recommendation to authenticate a signature prior to processing (executing potentially dangerous operations) and limiting the use of URIs since they may enable cross-site scripting attacks or access to local information.
  • XML Path Language (XPath) 2.0 [W3C.REC-xpath20-20101214] MUST be followed to specify the portion of the XML document to be signed. XPath is used to specify a location within an XML document. Best practice recommendations for using XPath [W3C.WD-xmldsig-bestpractices-20110809] SHOULD be referenced to reduce the risk of denial of service attacks. The use of XSLT transforms MUST be restricted according to security guidance in [W3C.WD-xmldsig-bestpractices-20110809].

XML Encryption

  • The document included in GRC-Exchange messages MAY be encrypted to provide an extra layer of security between peers so that the message is not only encrypted for transport. This behavior would be agreed upon between peers or a consortium, or determined on a per-message basis, depending on security requirements. It should be noted that there are cases for transport where the GRCPolicy class needs to be presented in clear text, as detailed in the transport document [RFC6546].
  • A Request, or any other message type that may be relayed through GRC-Exchange systems before reaching the intended destination as a result of trust relationships, MAY be encrypted specifically for the intended recipient. This may be necessary if the GRC-Exchange network is being used for message transfer, the intermediate parties do not need to have knowledge of the request contents, and a direct communication path does not exist. In that case, the GRCPolicy class is used by intermediate parties and as such, GRCPolicy is maintained in clear text.
  • A message may be encrypted using the key of the request originator, while leaving the GRC-Exchange contents in clear text. In that case, the intermediate parties can view the GRCPolicy information and know a response has been provided without seeing the contents of the response. If the use of encryption were limited to sections of the message, the History class information would be encrypted. Otherwise, it is RECOMMENDED to encrypt the entire included schema plus GRC-Exchange document and use an enveloped signature, for the originator of the request. The existence of the Result message for an incident would tell any intermediate parties used in the path of the incident investigation that the incident handling has been completed.
  • The restriction attribute sets expectations for the privacy of an incident and is defined in Section 4.1. Following the guidance for XML encryption in the Security Requirements Section, the restriction attribute can be set in any of the GRC-Exchange classes to define restrictions and encryption requirements for the exchange of GRC information. The restriction options enable encryption capabilities for the complete exchange of an XML document (including any extensions), within specific classes of a schema that embeds the restriction attribute where more limited restrictions are desired. The restriction attribute is contained in each of the GRC-Exchange classes and MUST be used in accordance with confidentiality expectations for either sections of the included XML document or the complete included XML document. Consortiums and organizations should consider this guidance when creating exchange policies.
  • Expectations based on restriction setting:
    • If restriction is set to "private", the class or document MUST be encrypted for the recipient using XML encryption and the public key of the recipient. See Section 11.2 for a discussion on public key infrastructure (PKI) and other security requirements.
    • If restriction is set to "need-to-know", the class or document MUST be encrypted to ensure only those with need-to-know access can decrypt the data. The document can either be encrypted for each individual for which access is intended or a single group key may be used. The method used SHOULD adhere to any certificate policy and practices agreements between entities for the use of GRC-Exchange. A group key in this instance refers to a single key (symmetric) that is used to encrypt the block of data. The users with need-to-know access privileges may be given access to the shared key via a secure distribution method, for example, providing access to the symmetric key encrypted with each of users public keys.
    • If restriction is set to "public", the class or document MUST be sent in clear text. This setting can be critical if certain sections of a document or an entire document are to be shared without restrictions. This provides flexibility within an exchange to share out certain information freely where appropriate.
    • If restriction is set to "default", The information can be shared according to an information disclosure policy pre-arranged by the communicating parties.

  • Expectations based on placement of the restriction setting:
    • If restriction is set within one of the GRC-Exchange classes, the restriction applies to the entire included XML document.
    • If restriction is set within individual classes of the included XML document, the restriction applies to the specific class and the children of that class.

The formation of policies is a very important aspect of using a messaging system like GRC-Exchange to exchange potentially sensitive information. Many considerations should be involved for peering parties, and some guidelines to protect the data, systems, and transport are covered in this section. Policies established should provide guidelines for communication methods, security, and fall-back procedures. See Sections 11.3 and Section 11.4 for additional information on consortiums and PKI considerations.

The security considerations for the storage and exchange of information in GRC-Exchange messaging may include adherence to local, regional, or national regulations in addition to the obligations to protect information. GRC-Exchange Policy is a necessary tool for listing the requirements of messages to provide a method to categorize data elements for proper handling. Controls are also provided for the sending entity to protect messages from third parties through XML encryption.

GRC-Exchange provides a method to exchange GRC request and Report messages between entities. Administrators have the ability to base decisions on the available resources and other factors of their enterprise and maintain control of GRC exchanges. Thus, GRC-Exchange provides the ability for participating networks to manage their own security controls, leveraging the information listed in GRCPolicy.

GRC-Exchange is used to transfer or exchange XML documents in an IANA registered format. Implementations SHOULD NOT download schemas at runtime due to the security implications, and included documents MUST NOT be required to provide a resolvable location of their schema.

11.2. Public Key Infrastructure

It is RECOMMENDED that GRC-Exchange, the XML security functions, and transport protocols properly integrate with a PKI managed by the consortium, federate PKIs within a consortium, or use a PKI managed by a trusted third party. Entities MAY use shared keys as an alternate solution, although this may limit the ability to validate certificates and could introduce risk. For the Internet, a few of examples of existing efforts that could be leveraged to provide the supporting PKI include the Regional Internet Registry's (RIR's) PKI hierarchy, vendor issued certificates, or approved issuers of Extended Validation (EV) Certificates. Security and privacy considerations related to consortiums are discussed in Sections 11.3 and Section 11.4.

The use of PKI between entities or by a consortium SHOULD adhere to any applicable certificate policy and practices agreements for the use of GRC-Exchange. [RFC3647] specifies a commonly used format for certificate policy (CP) and certification practices statements (CPS). Systems with predefined relationships for GRC-Exchange include those who peer directly or through a consortium with agreed-upon appropriate use agreements. The agreements to trust other entities may be based on assurance levels that could be determined by a comparison of the CP, CPS, and/or GRC-Exchange operating procedures. The initial comparison of policies and ability to audit controls provides a baseline assurance level for entities to form and maintain trust relationships. Trust relationships may also be defined through a bridged or hierarchical PKI in which both peers belong. If shared keys or keys issued from a common CA are used, the verification of controls to determine the assurance level to trust other entities may be limited to the GRC-Exchange policies and operating procedures.

XML security functions utilized in GRC-Exchange require a trust center such as a PKI for the distribution of credentials to provide the necessary level of security for this protocol. Layered transport protocols also utilize encryption and rely on a trust center. Public key certificate pairs issued by a trusted Certification Authority (CA) MAY be used to provide the necessary level of authentication and encryption for the GRC-Exchange protocol. The CA used for GRC-Exchange messaging must be trusted by all involved parties and may take advantage of similar efforts, such as the Internet2 federated PKI or the ARIN/RIR effort to provide a PKI to service providers. The PKI used for authentication also provides the necessary certificates needed for encryption used for the GRC-Exchange transport protocol [RFC6546].

11.2.1. Authentication

Hosts receiving a GRC-Exchange message MUST be able to verify that the sender of the request is valid and trusted. Using digital signatures on a hash of the GRC-Exchange message with an X.509 version 3 certificate issued by a trusted party MUST be used to authenticate the request. The X.509 version 3 specifications as well as the digital signature specifications and path validation standards set forth in [RFC5280] MUST be followed in order to interoperate with a PKI designed for similar purposes. Full path validation verifies the chaining relationship to a trusted root and also performs a certificate revocation check. The use of digital signatures in GRC-Exchange XML messages MUST follow the World Wide Web Consortium (W3C) recommendations for signature syntax and processing when either the XML encryption [W3C.REC-xmlenc-core-20021210] or digital signature [W3C.REC-xmldsig-core-20080610], [RFC3275] is used within a document.

It might be helpful to define an extension to the authentication scheme that uses attribute certificates [RFC5755] in such a way that an application could automatically determine whether human intervention is needed to authorize a request; however, the specification of such an extension is out of scope for this document.

The use of pre-shared keys may be considered for authentication at the transport layer. If this option is selected, the specifications set forth in "Pre-Shared Key Ciphersuites for Transport Layer Security (TLS)" [RFC4279] MUST be followed. Transport specifications are detailed in a separate document [RFC6546].

11.2.2. Multi-Hop Request Authentication

The use of multi-hop authentication in a Request is used when a Request is sent to multiple entities in an iterative manner. Multi-hop authentication is REQUIRED in Requests that involve multiple entities where Requests are forwarded iteratively through peers. Bilateral trust relationships MAY be used between peers, then Multi-hop authentication MUST be used for cases where the originator of a message is authenticated several hops into the message flow.

For practical reasons, entities may want to prioritize incident handling events based upon the immediate peer for a Request, the originator of a request, and other relevant information provided in metadata. In order to provide a higher assurance level of the authenticity of a Request, the originating GRC-Exchange system is included in the Request along with contact information and the information of all GRC-Exchange systems in the path the Request has taken. This information is provided through the GRC-Exchange From-Contact class nesting the list of systems and contacts involved in a request.

To provide multi-hop authentication, the originating GRC-Exchange system MUST include a digital signature in the Request sent to all systems in the upstream path. The signature MUST be passed to all parties that receive a Request, and each party MUST be able to perform full path validation on the digital signature [RFC5280]. In order to accommodate that requirement, the signed data MUST remain unchanged as a request is passed along between providers and may be restricted to one element for which the signature is applied. A second benefit to this requirement is that the integrity of the filter used is ensured as it is passed to subsequent entities in the upstream trace of the incident. The trusted PKI also provides the keys used to digitally sign the selected data element for a Request to meet the requirement of authenticating the original request. Any host in the path of the trace should be able to verify the digital signature using the trusted PKI.

In the case in which an enterprise using GRC-Exchange sends a Request to its provider, the signature from the enterprise MUST be included in the initial request. The provider may generate a new request to send upstream to members of the provider's consortium to continue the request. If the original request is sent, the originating provider, acting on behalf of the enterprise network with a request, MUST also digitally sign, with an enveloped signature, the full included XML document to assure the authenticity of the Request. A provider that offers GRC-Exchange as a service may be using its own PKI to secure GRC-Exchange communications between its GRC-Exchange system and the attached enterprise networks. Providers participating in the trace MUST be able to determine the authenticity of GRC-Exchange requests.

11.3. Consortiums and Public Key Infrastructures

Consortiums are an ideal way to establish a communication web of trust for GRC-Exchange messaging. It should be noted that direct relationships may be ideal for some communications, such as those between a provider of incident information and a subscriber of the incident reports. The consortium could provide centralized resources, such as a PKI, and established guidelines and control requirements for use of GRC-Exchange. The consortium may assist in establishing trust relationships between the participating providers to achieve the necessary level of cooperation and experience-sharing among the consortium entities. This may be established through PKI certificate policy [RFC3647] reviews to determine the appropriate trust levels between organizations or entities. The consortium may also be used for other purposes to better facilitate communication among providers in a common area (Internet, region, government, education, private networks, etc.).

Using a PKI to distribute certificates used by GRC-Exchange systems provides an already established method to link trust relationships between consortiums that peer with SPs belonging to a separate consortium. In other words, consortiums could peer with other consortiums to enable communication of GRC-Exchange messages between the participating providers. The PKI along with Memorandums of Agreement could be used to link border directories to share public key information in a bridge, a hierarchy, or a single cross-certification relationship.

Consortiums also need to establish guidelines for each participating provider to adhere. The RECOMMENDED guidelines include:

  • Physical and logical practices to protect GRC-Exchange systems;
  • Network and application layer protection for GRC-Exchange systems and communications;
  • Proper use guidelines for GRC-Exchange systems, messages, and requests; and
  • A PKI, certificate policy, and certification practices statement to provide authentication, integrity, and privacy.

The functions described for a consortium's role parallel that of a PKI federation. The PKI federations that currently exist are responsible for establishing security guidelines and PKI trust models. The trust models are used to support applications to share information using trusted methods and protocols.

A PKI can also provide the same level of security for communication between an end entity (enterprise, educational, or government customer network) and the provider.

11.4. Privacy Concerns and System Use Guidelines

Information sharing typically raises many concerns especially when privacy related information may be exchanged. The GRCPolicy class is used to automate the enforcement of the privacy concerns listed within this document. The privacy and system use concerns for the system communicating GRC-Exchange messages and other integrated components include the following:

Service Provider Concerns:

  • Privacy information contained in Human Resources, legal, compliance and other reports.

Customer Attached Networks Participating in GRC-Exchange with Provider:

  • Customer networks may include an enterprise, educational, government, or other attached networks to a provider participating in GRC-Exchange. Customers should review data handling policies to understand how data will be protected by a service provider. This information will enable customers to decide what types of data at what sensitivity level can be shared with service providers. This information could be used at the application layer to establish sharing profiles for entities and groups, see Section 11.5.
  • Customers should request information on the security and privacy considerations in place by their provider and the consortium of which the provider is a member. Customers should understand if their data were to be forwarded, how might it be sanitized and how will it be protected. Customers should also understand if limitations can be placed on how any data they share with their provider will be used in advance of sharing that data.
  • Customers should be aware that their data can and will be sent to other providers in order to complete a request unless an agreement stating otherwise is made in the service level agreements between the customer and provider. Customers considering privacy options may limit the use of this feature if they do not want the data forwarded.

Parties Involved in Exchanges:

  • Privacy of information such as the source and destination used for communication purposes over the monitored or GRC-Exchange connected network(s).
  • Protection of data from being viewed by intermediate parties in the path of an Request request should be considered.
  • Privacy of information exchanged in reports.

Consortium Considerations:

  • System use restrictions for information sharing within the local region's definitions of appropriate traffic. When participating in a consortium, appropriate use guidelines should be agreed upon and entered into contracts.
  • System use prohibiting the consortium's participating providers from inappropriately requesting information unlawfully within the jurisdiction or region.

Inter-Consortium Considerations:

  • System use between peering consortiums should consider any government communication regulations that apply between those two regions, such as encryption export and import restrictions.
  • System use between consortiums SHOULD NOT request information and actions beyond the scope intended and permitted by law or inter-consortium agreements.
  • System use between consortiums should consider national boundary issues and request limits in their appropriate system use agreements. Appropriate use should include restrictions to prevent the use of the protocol to limit or restrict traffic that is otherwise permitted within the country in which the peering consortium resides.

The security and privacy considerations listed above are for the consortiums, providers, and enterprises to agree upon. The agreed-upon policies may be facilitated through use of the GRCPolicy class and application layer options. Some privacy considerations are addressed through the GRC-Exchange guidelines for encryption and digital signatures as described in Section 11.1.

GRC-Exchange messaging privacy concerns should be elaborated on here...

Information shared through through GRC-Exchange could be sensitive. Such data in GRC-Exchange messages can be protected through the use of encryption [W3C.REC-xmlenc-core-20021210] enveloping the XML and GRC-Exchange document, using the public encryption key of the originating entity.

The decision is left to the system users and consortiums to determine appropriate data to be shared given that the goal of the specification is to provide the appropriate technical options to remain compliant. Local, state, or national laws may dictate the appropriate reporting requirements for specific exchange types.

Privacy becomes an issue whenever sensitive data traverses a network.

In the case of a Request or Report, where the originating provider is aware of the entity that will receive the request for processing, the free-form text areas of the document could be encrypted [W3C.REC-xmlenc-core-20021210] using the public key of the destination entity to ensure that no other entity in the path can read the contents. The encryption is accomplished through the W3C [W3C.REC-xmlenc-core-20021210] specification for encrypting an element.

GRC Report Exchanges must be legitimate incidents and not used for purposes such as sabotage or censorship. An example of such abuse of the system includes a report containing information about a competitor's compliance that may have been falsified to hurt their business.

Intra-consortium GRC-Exchange communications raise additional issues, especially when the peering consortiums reside in different regions or nations.

The GRC Report Exchange messages may be a valid use of the system within the confines of that country's network border; however, it may not be permitted to continue across network boundaries where such content is permitted under law. A continued Request, Query, or Report into a second country may break the laws and regulations of that nation. Any such messages MUST cease at the country's border.

The privacy concerns listed in this section address issues among the trusted parties involved in a trace within an provider, a GRC-Exchange consortium, and peering GRC-Exchange consortiums. Data used for GRC-Exchange communications must also be protected from parties that are not trusted. This protection is provided through the authentication and encryption of documents as they traverse the path of trusted servers and the local security controls in place for the GRC Report Exchange systems. Each GRC-Exchange system MUST perform a bi-directional authentication when sending a GRC-Exchange message and use the public encryption key of the upstream or downstream peer to send a message or document over the network. This means that the document is decrypted and re-encrypted at each GRC-Exchange system via TLS over a transport protocol such as [RFC6546]. The GRC-Exchange messages may be decrypted at each GRC-Exchange system in order to properly process the request or relay the information. Today's processing power is more than sufficient to handle the minimal burden of encrypting and decrypting relatively small typical GRC-Exchange messages.

11.5. Sharing Profiles and Policies

The application layer can be used to establish workflows and rulesets specific to sharing profiles for entities or consortiums. The profiles can leverage sharing agreements to restrict data types or classifications of data that are shared. The level of information or classification of data shared with any entity may be based on protection levels offered by the receiving entity and periodic validation of those controls. The profile may also indicate how far information can be shared according to the entity and data type. The profile can also support if requests to share data from an entity must go directly to that entity.

In some cases, pre-defined sharing profiles will be possible. These include any use case where an agreement is in place in advance of sharing. Examples may be between clients and providers, entities such as partners, or consortiums. There may be other cases when sharing profiles may not be established in advance. An organization may want to establish sharing profiles specific to possible user groups to prepare for possible incident scenarios. The user groups could include business partners, industry peers, service providers, experts not part of a service provider, law enforcement, or regulatory repotting bodies.

Workflows to approve transactions may be specific to sharing profiles and data types. Application developers should include capabilities to enable these decision points for users of the system.

Any expectations between entities to preserve the weight and admissibility of evidence should be handled at the policy and agreement level. A sharing profile may include notes or an indicator for approvers in workflows to reflect if such agreements exist.

12. Security Considerations

GRC Report Exchange has many security requirements and considerations built into the design of the protocol, several of which are described in the Security Requirements section. For a complete view of security, considerations include the availability, confidentiality, and integrity concerns for the transport, storage, and exchange of information.

Authenticated encrypted tunnels between systems accepting GRC-Exchange communications are used to provide confidentiality, integrity, authenticity, and privacy for the data at the transport layer. Encryption and digital signatures are also used at the GRC XML document level through GRC-Exchange options to provide confidentiality, integrity, authenticity, privacy and traceability of the document contents. Trust relationships may be through direct peers or consortiums using established trust relationships of public key infrastructure (PKI) via cross-certifications. Trust levels can be established in cross-certification processes where entities compare PKI policies that include the specific management and handling of an entity's PKI and certificates issued under that policy. [RFC3647] defines an Internet X.509 Public Key Infrastructure Certificate Policy and Certification Practices Framework that may be used in the comparison of policies to establish trust levels and agreements between entities, an entity and a consortium, and consortia. The agreements SHOULD consider key management practices including the ability to perform path validation on certificates [RFC5280], key distribution techniques [RFC2585], Certificate Authority and Registration Authority management practices.

The agreements between entities SHOULD also include a common understanding of the usage of GRC-Exchange security, policy, and privacy options discussed in this section. The formality, requirements, and complexity of the agreements for the certificate policy, practices, and the use of GRC-Exchange options SHOULD be decided by the entities or consortiums creating those agreements.

13. IANA Considerations

This document uses URNs to describe XML namespaces [W3C.REC-xml-names-20091208] and XML schemas [W3C.REC-xmlschema-1-20041028] conforming to a registry mechanism described in [RFC3688].

Registration request for the grc-exchange namespace:

  • URI: urn:ietf:params:xml:ns:grc-exchange-1.0
  • Registrant Contact: See the "Author's Address" section of this document.
  • XML: None. Namespace URIs do not represent an XML specification.
  • Registration request for the grc-exchange XML schema:
  • URI: urn:ietf:params:xml:schema:grc-exchange-1.0
  • Registrant Contact: See the "Author's Address" section of this document.
  • XML: See Section 4, "GRC-Exchange Schema", of this document.

Request for the specified registry to be created and managed by IANA:

  • Name of the registry:"XML Schemas Exchanged via GRC-Exchange"
  • Namespace details: A registry entry for an XML Schema Transferred via GRC-Exchange consists of:
    • Schema Name: A short string that represents the schema referenced. This value is for reference only in the table. The version of the schema MUST be included in this string to allow for multiple versions of the same specification to be in the registry.
    • Version: The version of the registered XML schema. The version is a string that SHOULD be formatted as numbers separated by a '.' (period) character.
    • Namespace: The namespace of the referenced XML schema. This is represented in the GRC-Exchange GRCDocument class in the XMLSchemaID attribute as an enumerated value is represented by a URN or URI.
    • Specification URI: A URI [RFC3986] from which the registered specification can be obtained. The specification MUST be publicly available from this URI.

  • Information that must be provided to assign a new value: The above list of information.
  • Fields to record in the registry: Schema Name/Version/Namespace/Specification URI
  • Initial registry contents: See section Section 13
  • Allocation Policy: Expert Review [RFC5226] and Specification Required [RFC5226].

The Designated Expert is expected to consult with the MILE (Managed Incident Lightweight Exchange) working group or its successor if any such WG exists (e.g., via email to the working group's mailing list). The Designated Expert is expected to retrieve the XML schema specification from the provided URI in order to check the public availability of the specification and verify the correctness of the URI. An important responsibility of the Designated Expert is to ensure that the XML schema is appropriate for use in GRC-Exchange.

Request for the specified registry to be created and managed by IANA:

  • Name of the registry:"GRC-Exchange Enumeration List"
  • The registry is intended to enable enumeration value additions to attributes in the grc-exchange XML schema.
  • Fields to record in the registry: Attribute Name/Attribute Value/Description
  • Initial registry content: none.
  • Allocation Policy: Expert Review [RFC5226]

The Designated Expert is expected to consult with the mile (Managed Incident Lightweight Exchange) working group or its successor if any such WG exists (e.g., via email to the working group's mailing list). The Designated Expert is expected to review the request and validate the appropriateness of the enumeration for the attribute. If a draft specification is associated with the request, it MUST be reviewed by the Designated Expert.

14. Acknowledgements

Many thanks to colleagues and the Internet community for reviewing and commenting on the document.

15. Summary

Governance, Risk, and Compliance reports may contain some of the most sensitive information for a business. Reports may contain the prioritized risks for the effective management of Business Operations, IT, Security, Compliance, and Legal departments of an enterprise. There may be a regulatory or legal requirement to share information or formatted reports with a regulatory body or other entities in a legal review. Outsourcing of computer infrastructure has necessitated the need for service providers to share reports with tenants or clients to ensure SLAs and agreements on security requirements are met. Each of these use cases require a secure method to exchange reports. GRC Report Exchange provides a standardized method to exchange reports while considering the security, privacy and policy requirements without relying on the transport layer for security. Security is provided at the document level to provide methods to share a report where policy requirements can be implemented by mapping to technical options and data markers in the GRC-Exchange protocol.

16. References

16.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2585] Housley, R. and P. Hoffman, "Internet X.509 Public Key Infrastructure Operational Protocols: FTP and HTTP", RFC 2585, May 1999.
[RFC3275] Eastlake, D., Reagle, J. and D. Solo, "(Extensible Markup Language) XML-Signature Syntax and Processing", RFC 3275, March 2002.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet: Timestamps", RFC 3339, July 2002.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004.
[RFC3986] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005.
[RFC4051] Eastlake, D., "Additional XML Security Uniform Resource Identifiers (URIs)", RFC 4051, April 2005.
[RFC4279] Eronen, P. and H. Tschofenig, "Pre-Shared Key Ciphersuites for Transport Layer Security (TLS)", RFC 4279, December 2005.
[RFC4519] Sciberras, A., "Lightweight Directory Access Protocol (LDAP): Schema for User Applications", RFC 4519, June 2006.
[RFC5070] Danyliw, R., Meijer, J. and Y. Demchenko, "The Incident Object Description Exchange Format", RFC 5070, December 2007.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R. and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, May 2008.
[RFC5322] Resnick, P., "Internet Message Format", RFC 5322, October 2008.
[RFC5646] Phillips, A. and M. Davis, "Tags for Identifying Languages", BCP 47, RFC 5646, September 2009.
[RFC5755] Farrell, S., Housley, R. and S. Turner, "An Internet Attribute Certificate Profile for Authorization", RFC 5755, January 2010.
[RFC5890] Klensin, J., "Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework", RFC 5890, August 2010.
[RFC5891] Klensin, J., "Internationalized Domain Names in Applications (IDNA): Protocol", RFC 5891, August 2010.
[RFC6545] Moriarty, K., "Real-time Inter-network Defense (RID)", RFC 6545, February 2012.
[W3C.REC-xml-20081126] Sperberg-McQueen, C., Yergeau, F., Maler, E., Paoli, J. and T. Bray, "Extensible Markup Language (XML) 1.0 (Fifth Edition)", World Wide Web Consortium Recommendation REC-xml-20081126, November 2008.
[W3C.REC-xml-names-20091208] Hollander, D., Layman, A., Bray, T., Tobin, R. and H. Thompson, "Namespaces in XML 1.0 (Third Edition)", World Wide Web Consortium Recommendation REC-xml-names-20091208, December 2009.
[W3C.REC-xmlenc-core-20021210] Eastlake, D. and J. Reagle, "XML Encryption Syntax and Processing", World Wide Web Consortium Recommendation REC-xmlenc-core-20021210, December 2002.
[W3C.REC-xmlschema-1-20041028] Thompson, H., Beech, D., Mendelsohn, N. and M. Maloney, "XML Schema Part 1: Structures Second Edition", World Wide Web Consortium Recommendation REC-xmlschema-1-20041028, October 2004.
[W3C.REC-xmldsig-core-20080610] Solo, D., Roessler, T., Eastlake, D., Hirsch, F. and J. Reagle, "XML Signature Syntax and Processing (Second Edition)", World Wide Web Consortium Recommendation REC-xmldsig-core-20080610, June 2008.
[W3C.CR-xmldsig-core1-20110303] Eastlake, D., Nyström, M., Solo, D., Reagle, J., Roessler, T., Hirsch, F. and K. Yiu, "XML Signature Syntax and Processing Version 1.1", World Wide Web Consortium CR CR-xmldsig-core1-20110303, March 2011.
[W3C.WD-xmldsig-bestpractices-20110809] Datta, P. and F. Hirsch, "XML Signature Best Practices", World Wide Web Consortium WD WD-xmldsig-bestpractices-20110809, August 2011.
[W3C.REC-xpath20-20101214] Robie, J., Berglund, A., Fernández, M., Boag, S., Chamberlin, D., Siméon, J. and M. Kay, "XML Path Language (XPath) 2.0 (Second Edition)", World Wide Web Consortium Recommendation REC-xpath20-20101214, December 2010.

16.2. Informative References

[RFC4180] Shafranovich, Y., "Common Format and MIME Type for Comma-Separated Values (CSV) Files", RFC 4180, October 2005.
[RFC6194] Polk, T., Chen, L., Turner, S. and P. Hoffman, "Security Considerations for the SHA-0 and SHA-1 Message-Digest Algorithms", RFC 6194, March 2011.
[RFC3492] Costello, A., "Punycode: A Bootstring encoding of Unicode for Internationalized Domain Names in Applications (IDNA)", RFC 3492, March 2003.
[RFC4765] Debar, H., Curry, D. and B. Feinstein, "The Intrusion Detection Message Exchange Format (IDMEF)", RFC 4765, March 2007.
[RFC3647] Chokhani, S., Ford, W., Sabett, R., Merrill, C. and S. Wu, "Internet X.509 Public Key Infrastructure Certificate Policy and Certification Practices Framework", RFC 3647, November 2003.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008.
[ISO.8601.2000] International Organization for Standardization, "Data elements and interchange formats -- Information interchange -- Representation of dates and times", ISO Standard 8601, December 2000.

Authors' Addresses

Kathleen M. Moriarty EMC Corporation 176 South Street Hopkinton, MA, United States EMail: Kathleen.Moriarty@emc.com
Said Tabet EMC Corporation 176 South Street Hopkinton, MA, United States EMail: Said.Tabet@emc.com
David Waltermire National Institute of Standards and Technology 100 Bureau Drive Gaithersburg, MD, United States EMail: david.waltermire@nist.gov