view Side-By-Side changes
KITTEN WGNetwork Working Group N. WilliamsInternet-DraftRequest for Comments: 5554 Sun Updates:rfc2743 April 6,2743 May 2009(if approved) Intended status:Category: Standards TrackExpires: October 8, 2009Clarifications and Extensions to theGSS-APIGeneric Security Service Application Program Interface (GSS-API) for the Use of Channel Bindingsdraft-ietf-kitten-gssapi-channel-bindings-07.txtStatus ofthisThis Memo ThisInternet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents ofdocument specifies an Internet standards track protocol for the InternetEngineering Task Force (IETF), its areas,community, andits working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents validrequests discussion and suggestions fora maximumimprovements. Please refer to the current edition ofsix monthsthe "Internet Official Protocol Standards" (STD 1) for the standardization state andmay 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." The liststatus ofcurrent Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The listthis protocol. Distribution ofInternet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on October 8, 2009.this memo is unlimited. Copyright Notice Copyright (c) 2009 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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document.Williams Expires October 8, 2009 [Page 1] Internet-Draft GSS-API Channel Bindings April 2009Abstract This document clarifies and generalizes the Generic SecurityServicesService Application Programming Interface (GSS-API) "channel bindings" facility, and imposes requirements on future GSS-API mechanisms and programming language bindings of the GSS-API. Table of Contents 1. Introduction ....................................................2 2. ConventionsusedUsed inthis document . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4This Document ...............................2 3. New Requirements for GSS-API Mechanisms. . . . . . . . . . . 5.........................2 4. Generic Structure for GSS-API Channel Bindings. . . . . . . . 6..................2 5.IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 6.Security Considerations. . . . . . . . . . . . . . . . . . . 9 7..........................................3 6. References. . . . . . . . . . . . . . . . . . . . . . . . . . 10 7.1.......................................................4 6.1. Normative References. . . . . . . . . . . . . . . . . . . 10 7.2........................................4 6.2. Informative References. . . . . . . . . . . . . . . . . . 10 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 11.....................................4 WilliamsExpires October 8, 2009Standards Track [Page2] Internet-Draft1] RFC 5554 GSS-API Channel BindingsAprilMay 2009 1.Conventions used in this document 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]. Williams Expires October 8, 2009 [Page 3] Internet-Draft GSS-API Channel Bindings April 2009 2.Introduction The base GSS-APIv2,version 2, update 1 specification [RFC2743] provides a facility for channel binding (see also [RFC5056]), but its treatmentwasis incomplete. TheC-bindings of theGSS-API C-bindings specification [RFC2744]expanded a littleexpands somewhat on this facility in what shouldhave beenbe a generic way, butwasis instead a C-specific way,and still,thus leaving the treatment of this facilitywasincomplete. This document clarifies the GSS-API's channel binding facility and generalizes the parts of it that are specified in the C-bindings document butwhichthat should have been generic from thefirst. Williams Expires October 8, 2009 [Page 4] Internet-Draft GSS-API Channel Bindings April 2009start. 2. Conventions Used in This Document 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]. 3. New Requirements for GSS-API Mechanisms Given the publication ofRFC5056RFC 5056, we now assert that all new GSS-API mechanisms that support channel binding MUST conform to [RFC5056].Williams Expires October 8, 2009 [Page 5] Internet-Draft GSS-API Channel Bindings April 20094. Generic Structure for GSS-API Channel Bindings The base GSS-APIv2,version 2, update 1 specification [RFC2743] provides a facility for channel binding. It models channel bindings as an OCTET STRING and leaves it to the GSS-APIv2,version 2, update 1C-BindingsC-bindings specification to specify the structure of the contents of the channel bindings OCTET STRINGs. TheC-BindingsC-bindings specification [RFC2744] then defines, in terms of C, what should have been a generic structure for channel bindings. The Kerberos V GSS mechanism [RFC4121] also defines a method for encoding GSS channel bindings in a way that is independent of theC-BindingsC-bindings --otherwiseotherwise, the mechanism's channel binding facility would not be useable with other language bindings. In other words, the structure of GSS channel bindings given in [RFC2744] is actuallygeneric, rather than specific to thegeneric in spite of being specified in terms of Cprogramming language.concepts and syntax. We generalize it as shown below, using the same pseudo-ASN.1 as is used inRFC2743.RFC 2743. Although the figure below is, indeed, a valid ASN.1[CCITT.X680.2002][CCITT.X680] type, we do not provide a full ASN.1 module as none is needed because no standard encoding of this structure is needed -- the definition below is part of an abstract API, not part Williams Standards Track [Page 2] RFC 5554 GSS-API Channel Bindings May 2009 of a protocol defining bits on the wire. GSS-API mechanisms do need to encode the contents of this structure, but that encoding will be mechanism specific (see below). GSS-CHANNEL-BINDINGS ::= SEQUENCE { initiator-address-type INTEGER, -- See RFC2744 initiator-address OCTET STRING, -- See RFC2744 acceptor-address-type INTEGER, -- See RFC2744 acceptor-address OCTET STRING, -- See RFC2744 application-data OCTET STRING -- See RFC5056 } Abstract GSS-APIchannel bindings structureChannel Bindings Structure The values for the address fields are described in [RFC2744]. New language-specific bindings of the GSS-API SHOULD specify a language-specific formulation of this structure. Where a language binding of the GSS-API models channel bindings as OCTET STRINGs (or the language's equivalent), then the implementation MUST assume that the given bindings correspond only to the application-data field of GSS-CHANNEL-BINDINGS as shown above, rather than some encoding of GSS-CHANNEL-BINDINGS. As mentioned above, [RFC4121] describes an encoding of the above GSS-Williams Expires October 8, 2009 [Page 6] Internet-Draft GSS-API Channel Bindings April 2009CHANNEL-BINDINGSstructure,structure and then hashes that encoding. OtherGSS-APIGSS- API mechanisms are free to use that encoding.Williams Expires October 8, 2009 [Page 7] Internet-Draft GSS-API Channel Bindings April 20095.IANA Considerations There are no IANA considerations in this document. Williams Expires October 8, 2009 [Page 8] Internet-Draft GSS-API Channel Bindings April 2009 6.Security Considerations For general security considerations relating to channelbindingsbindings, see [RFC5056]. Language bindings that use OCTET STRING (or equivalent) for channel bindings will not support the use of network addresses as channel bindings. This should not cause any security problems, as the use of network addresses as channel bindings is not generally secure. However, it is important that "end-point channel bindings" not bemodelledmodeled as networkaddresses, otherwiseaddresses; otherwise, such channel bindings may not be useable with all language bindings of the GSS-API. WilliamsExpires October 8, 2009Standards Track [Page9] Internet-Draft3] RFC 5554 GSS-API Channel BindingsAprilMay 20097.6. References7.1.6.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2743] Linn, J., "Generic Security Service Application Program Interface Version 2, Update 1", RFC 2743, January 2000. [RFC2744] Wray, J., "Generic Security Service API Version 2 : C-bindings", RFC 2744, January 2000. [RFC4121] Zhu, L., Jaganathan, K., and S. Hartman, "The Kerberos Version 5 Generic Security Service Application Program Interface (GSS-API) Mechanism: Version 2", RFC 4121, July 2005. [RFC5056] Williams, N., "On the Use of Channel Bindings to Secure Channels", RFC 5056, November 2007.7.2.6.2. Informative References[CCITT.X680.2002] International[CCITT.X680] International Telephone and Telegraph Consultative Committee, "Abstract Syntax Notation One (ASN.1): Specification of basic notation", CCITT Recommendation X.680, July 2002.Williams Expires October 8, 2009 [Page 10] Internet-Draft GSS-API Channel Bindings April 2009Author's Address Nicolas Williams Sun Microsystems 5300 Riata Trace Ct Austin, TX 78727 USEmail:EMail: Nicolas.Williams@sun.com WilliamsExpires October 8, 2009Standards Track [Page11]4] ----