NETWORK WORKING GROUP N. Williams Internet-Draft Sun Expires: December 30, 2004 July 2004 GSS-API Domain-Based Service Names and Name Type draft-williams-gssapi-domain-based-names-00.txt Status of this Memo By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on December 30, 2004. Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract This document describes domainname-based service principal names and the corresponding name type for the GSS-API. Domain-based service names are similar to host-based service names, but using a domain name (not necessarily and Internat domain name) instead of or in addition to a hostname. The primary purpose of domain-based service names is to provide a way to name clustered services after the domain which they service, thereby allowing their clients to authorize the service's servers based on authentication of their names. Williams Expires December 30, 2004 [Page 1] Internet-Draft GSS Domain Based Names July 2004 Table of Contents 1. Conventions used in this document . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Name Type OID and Symbolic Name . . . . . . . . . . . . . . . . 5 4. Query and Display Syntaxes . . . . . . . . . . . . . . . . . . . 6 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 8 7. Normative . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8 Intellectual Property and Copyright Statements . . . . . . . . . 9 Williams Expires December 30, 2004 [Page 2] Internet-Draft GSS Domain Based Names July 2004 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 December 30, 2004 [Page 3] Internet-Draft GSS Domain Based Names July 2004 2. Introduction The use of hostbased principal names for domain-wide services presents the problem of how to distinguish between an instance of a hostbased service that is authorized to respond for a domain and one that isn't. Consider LDAP. LDAP with SASL and the Kerberos V GSS-API mechanism uses a hostbased principal with a service name of "ldap", a reasonable approach, provided there is only one logical LDAP directory in a Kerberos realm's domain, and that all ldap servers in that realm serve that one LDAP directory. If there were other LDAP directories, then clients could not tell which service is authorized to serve which directory, not without assuming a secure method for finding LDAP servers (e.g., DNSSEC). This is a significant, and oft-unstated restriction on users of LDAP. Domain based names can eliminate this problem by allowing LDAP service names to indicate which LDAP directory they are authorized to serve. A domain-based name consists of three required elements: o a service name o a domain name o a hostname Williams Expires December 30, 2004 [Page 4] Internet-Draft GSS Domain Based Names July 2004 3. Name Type OID and Symbolic Name The new name type has an OID of [NOTE: OID assignment to be made with IANA.] {iso(1) org(3) dod(6) internet(1) security(5) nametypes(6) gss-domain-based(5)} The recommended symbolic name for this GSS-API name type is "GSS_C_NT_DOMAINBASED_SERVICE". Williams Expires December 30, 2004 [Page 5] Internet-Draft GSS Domain Based Names July 2004 4. Query and Display Syntaxes There is a single syntax that applies to both query and display forms of domain-based names. (We ignore string profile matters here as the GSS-API's, and its mechanisms' use of character strings are out of scope for this document.) The syntax is: domain-based-name := | '@' '@' | '@@' The domain name element is only optional in the query syntax of domain-based names. A missing domain name is always to be added by the GSS-API mechanisms during name canonicalization, using whatever default values are appropriate for the mechanisms. Therefore the display form of domain-based MNs (see [RFC2743]) MUST include all three elements of domain-based names. Note that for Internet domain names the trailing '.' is not and MUST NOT be included in the domain name (or hostname) parts of the display form GSS-API domain-based MNs. Williams Expires December 30, 2004 [Page 6] Internet-Draft GSS Domain Based Names July 2004 5. Examples o ldap@@ds1.example.tld o ldap@example.tld@ds1.example.tld o kadmin@@kdc1.example.tld o kadmin@example.tld@kdc1.example.tld Williams Expires December 30, 2004 [Page 7] Internet-Draft GSS Domain Based Names July 2004 6. Security Considerations Use of GSS-API domain-based names may not be negotiable by some GSS-API mechanisms, and some acceptors may not support GSS-API domain-based names. In such cases initiators are left to fallback on the use of hostbased names, in which case the initiators MUST also verify that the acceptor's hostbased name is authorized to provide the given service for the domain that the initiator had wanted. The above security consideration also applies to all GSS-API initiators who lack support for domain-based service names. 7 Normative [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. Author's Address Nicolas Williams Sun Microsystems 5300 Riata Trace Ct Austin, TX 78727 US EMail: Nicolas.Williams@sun.com Williams Expires December 30, 2004 [Page 8] Internet-Draft GSS Domain Based Names July 2004 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. 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Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2004). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Williams Expires December 30, 2004 [Page 9]