Registry Specification for Mandatory Access Control (MAC) Security Label Formats
The information below is for an old version of the document.
This is an older version of an Internet-Draft that was ultimately published as RFC 7569.
|Authors||David Quigley , Jarrett Lu , Thomas Haynes|
|RFC stream||Internet Engineering Task Force (IETF)|
GENART Last Call review (of -02) Ready with Issues
|Additional resources||Mailing list discussion|
|Stream||WG state||WG Document|
|IESG||IESG state||I-D Exists|
|Send notices to||(None)|
NFSv4 D. Quigley Internet-Draft Intended status: Standards Track J. Lu Expires: November 2, 2014 Oracle T. Haynes Primary Data May 01, 2014 Registry Specification for Mandatory Access Control (MAC) Security Label Formats draft-ietf-nfsv4-lfs-registry-00.txt Abstract In the past Mandatory Access Control (MAC) systems have used very rigid policies which were hardcoded into the particular protocol and platform. As MAC systems are more widely deployed additional flexibility in mechanism and policy is required. Where traditional trusted systems implemented Multi-Level Security (MLS) and integrity models, modern systems have expanded to include technologies such as type enforcement. Due to the wide range of policies and mechanisms it has proven through past efforts to be virtually impossible to accomodate all parties in one security label format and model. To allow multiple MAC mechanisms and label formats in a network, this document proposes a registry of label format specifications. This registry contains several identifiers to accomodate both integer and string preferences and associates those identifiers with an extensive document outlining the exact syntax and use of the particular label format. 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 November 2, 2014. Quigley, et al. Expires November 2, 2014 [Page 1] Internet-Draft Labeled NFS Registry May 2014 Copyright Notice Copyright (c) 2014 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 . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Requirements Language . . . . . . . . . . . . . . . . . . . . 4 4. Exisiting Label Format Specifications . . . . . . . . . . . . 4 4.1. Commercial IP Security Option (CIPSO) . . . . . . . . . . 4 4.2. Common Architecture Label IPv6 Security Option (CALIPSO) 4 4.3. Flux Advanced Security Kernel (FLASK) . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 6.1. Initial Registry . . . . . . . . . . . . . . . . . . . . 5 6.2. Adding a New Entry to the Registry . . . . . . . . . . . 5 6.3. Obsoleting a Label Format Selector . . . . . . . . . . . 6 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.1. Normative References . . . . . . . . . . . . . . . . . . 6 7.2. Informative References . . . . . . . . . . . . . . . . . 7 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 7 Appendix B. RFC Editor Notes . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction With the acceptance of security labels in several mainstream operating systems the need to communicate labels between these systems becomes more important. In a typical client and server scenario, the client request to the server acts as a subject trying to access an object on the server [RFC7204]. Unfortunately these systems are diverse enough that attempts at establishing one common label format have been unsucessful. The reason for this is that systems implement different Mandatory Access Control (MAC) models, which typically do not share any common ground. Quigley, et al. Expires November 2, 2014 [Page 2] Internet-Draft Labeled NFS Registry May 2014 One solution is to define a single label format which consists of the union of the requirements of all MAC models/implementations. This is not ideal because it introduces an environment where many MAC models would either have blank fields for many of the label's components or will ignore the values that are present all together. This environment introduces waste and complexity where it is not needed. Additionally if a policy authority or identifier field is specified in the label format it would require a robust description that could be implemented which would lock policy administration into the described model. Ideally a mechanism to address this problem should allow the most flexibility possible in terms of policy administration while providing a specification that is suffient to allow for implementation of the label format and understanding of the semantics of the label. This means that the label format specification would ideally contain a syntactic description of the label format and a description of the semantics for each component in the label. This allows protocols to specify the type of label and label semantics that it requires while leaving policy and policy administration to the individual organizations using the protocol in their environment. Policy administration within an organization is a difficult problem. This should not be made even more difficult by having to request permission from external entities when crafting new policy or just making department specific modifications to existing policies. The policy authority field would allow an label format specification to specify a scheme for policy administration without forcing it on all users of security labels. However by agreeing to implement a particular label format specification, the protocol agrees to that policy administration mechanism when processing labels of that type. 2. Definitions Label Format Specification: an identifier used by the client to establish the syntactic format of the security label and the semantic meaning of its components. Multi-Level Security (MLS): a traditional model where objects are given a sensitivity level (Unclassified, Secret, Top Secret, etc.) and a category set [RH_MLS]. Object: a passive resource within the system that we wish to protect. Objects can be entities such as files, directories, pipes, sockets, and many other system resources relevant to the protection of the system state. Quigley, et al. Expires November 2, 2014 [Page 3] Internet-Draft Labeled NFS Registry May 2014 Subject: an active entity, usually a process, that is requesting access to an object. 3. Requirements Language 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]. 4. Exisiting Label Format Specifications 4.1. Commercial IP Security Option (CIPSO) The Commercial IP Security Option (CIPSO) label format specification is documented in [CIPSO]. While this draft has expired a long time ago, it is the defacto standard for labeled networking. It is also documented in [FIPS-188]. 4.2. Common Architecture Label IPv6 Security Option (CALIPSO) The Common Architecture Label IPv6 Security Option (CALIPSO) [CIPSO] is a successor to CIPSO. 4.3. Flux Advanced Security Kernel (FLASK) The Flux Advanced Security Kernel (FLASK) is an impelementation of an architecture to provide flexible support for security policies. 5. Security Considerations This document defines a mechanism to associate LFS identifier with a document outlining the syntax and format of a label. There is no security consideration in such an association. The label specification documents referenced by each registration entry should state security considerations for the label mechanism it specifies. 6. IANA Considerations This section provides guidance to the Internet Assigned Numbers Authority (IANA) regarding creation of a new registry in accordance with [RFC5226]. This submission requests the creation of a new registry called "Security Label Format Selection Registry". The new registry has the following fields: Quigley, et al. Expires November 2, 2014 [Page 4] Internet-Draft Labeled NFS Registry May 2014 Label Format Selector: An integer number that maps to a particular label format, e.g., the CALIPSO label format defined by [RFC5570]. The name space of this identifier has the range of 0..65,535. Label Description: A human readable ASCII text string that describes the label format, e.g., "Common Architecture Label IPv6 Security Option (CALIPSO)". The length of this field is limited to 128 bytes. Status: A short ASCII text string indicating the status of an entry in the registry. The status field for most entries should have the value "active". In the case that a label format selection entry is obsolete, the status field of the obsoleted entry should be "obsoleted by entry NNN". Label Format Specification: A reference to a stable, public document that specify the label format, e.g., an URL to [RFC5570]. 6.1. Initial Registry The initial assignments of the registry are as follows: +-----------------+------------------+--------+---------------------+ | Label Format | Description | Status | Reference | | Selector | | | | +-----------------+------------------+--------+---------------------+ | 0 | Reserved | - | - | | 1 - 127 | Private Use | - | - | | 128 - 255 | Experimental Use | - | - | | 256 | CIPSO (tag type | active | [[CIPSO] URL] | | | #1) | | | | 257 | CALIPSO (RFC | active | [[RFC5570] URL] | | | 5570) | | | | 258 | FLASK Security | active | [[FLASK] URL] | | | Context | | | | 258 - 65535 | Unassigned | - | - | +-----------------+------------------+--------+---------------------+ Label Format Specifier Ranges Table 1 6.2. Adding a New Entry to the Registry A label format specification document is required to add a new entry to this registry. If the label format document is inside the RFC path, then The IANA Consideration section of the label format document should clearly reference the Label Format Selection registry Quigley, et al. Expires November 2, 2014 [Page 5] Internet-Draft Labeled NFS Registry May 2014 and request allocation of a new entry. The well-known IANA policy, Specification Required, as defined in section 4.1 of [RFC5226], will be used to handle such requests. Note that "Specification Required" policy implies this process requires a Designated Expert reviewer, i.e., adding a new entry to this registry requires both a published label format specification and a Designated Expert review. 6.3. Obsoleting a Label Format Selector In the case that a label format selector number is assigned to a label format and the label format specification is changed later, a new selector assignment should be requested. The same Specification Required IANA policy applies to such requests. The IANA Consideration section of the updated label format specification should be explicit in which old label selector assignment it obsoletes. Below is an example of obsoleted entry in the registry: +---------------+-------------------+------------+------------------+ | Label Format | Description | Status | Reference | | Selector | | | | +---------------+-------------------+------------+------------------+ | 0 | Reserved | - | - | | 1 - 127 | Private Use | - | - | | 128 - 255 | Experimental Use | - | - | | 256 | CIPSO (tag type | active | [[CIPSO] URL] | | | #1) | | | | 257 | CALIPSO (RFC | active | [[RFC5570] URL] | | | 5570) | | | | 258 | FLASK Security | obsoleted | [[FLASK] URL] | | | Context | by 263 | | | ... | | | | | 263 | FLASK Security | active | [new spec URL] | | | Context (v2) | | | | 264 - 65535 | Unassigned | - | - | +---------------+-------------------+------------+------------------+ Example Label Format Specifier Updated Ranges Table 2 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", March 1997. Quigley, et al. Expires November 2, 2014 [Page 6] Internet-Draft Labeled NFS Registry May 2014 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. 7.2. Informative References [CIPSO] IETF CIPSO Working Group, "Commercial IP Security Option (CIPSO 2.2)", draft-ietf-cipso-ipsecurity-01 (expired), July 1992. [FIPS-188] US National Institute of Standards and Technology, "Standard Security Labels for Information Transfer", Federal Information Processing Standard (FIPS) 188, September 1994. [FLASK] Spencer, R., Smalley, S., Loscocco, P., Hibler, M., Andersen, D., and J. Lepreau, "The Flask Security Architecture: System Support for Diverse Security Policies", In Proceedings of the Eighth USENIX Security Symposium, pages 123-139 , August 1999. [RFC5570] StJohns, M., Atkinson, R., and G. Thomas, "Common Architecture Label IPv6 Security Option (CALIPSO)", RFC 5570, July 2009. [RFC7204] Haynes, T., "Requirements for Labeled NFS", RFC 7204, April 2014. [RH_MLS] "Multi-Level Security (MLS)", "Deployment, configuration and administration of Red Hat Enterprise Linux 5, Edition 10", Section 49.6, 2013, <http://docs.redhat.com/docs/ en-US/Red_Hat_Enterprise_Linux/5/html/Deployment_Guide/ sec-mls-ov.html>. Appendix A. Acknowledgments Appendix B. RFC Editor Notes [RFC Editor: please remove this section prior to publishing this document as an RFC] Authors' Addresses David P. Quigley Email: firstname.lastname@example.org Quigley, et al. Expires November 2, 2014 [Page 7] Internet-Draft Labeled NFS Registry May 2014 Jarrett Lu Oracle Email: email@example.com Thomas Haynes Primary Data, Inc. 4300 El Camino Real Ste 100 Los Altos, CA 94022 USA Phone: +1 408 215 1519 Email: firstname.lastname@example.org Quigley, et al. Expires November 2, 2014 [Page 8]