Network Working Group A. Newton Internet-Draft VeriSign, Inc. Expires: April 8, 2005 October 8, 2004 A Domain Availability Check (dchk) Registry Type for the Internet Registry Information Service (IRIS) draft-ietf-crisp-iris-dchk-01 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 April 8, 2005. Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract This document describes a lightweight domain availability service using the IRIS framework and the data model of the IRIS Domain Registry service. Newton Expires April 8, 2005 [Page 1] Internet-Draft iris-dchk October 2004 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Document Terminology . . . . . . . . . . . . . . . . . . . . . 4 3. DCHK Registry . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1 Schema Description . . . . . . . . . . . . . . . . . . . . 5 3.1.1 The Result . . . . . . . . . . . . . . . . . 5 3.1.2 Support for . . . . . . . . . . . 6 3.2 DCHK Formal XML Syntax . . . . . . . . . . . . . . . . . . 6 3.3 BEEP Transport Compliance . . . . . . . . . . . . . . . . 10 3.3.1 Message Pattern . . . . . . . . . . . . . . . . . . . 10 3.3.2 Server Authentication . . . . . . . . . . . . . . . . 10 3.4 URI Resolution . . . . . . . . . . . . . . . . . . . . . . 10 3.4.1 Application Service Label . . . . . . . . . . . . . . 10 3.4.2 Bottom-Up Resolution . . . . . . . . . . . . . . . . . 10 3.4.3 Top-Down Resolution . . . . . . . . . . . . . . . . . 11 4. Internationalization Considerations . . . . . . . . . . . . . 12 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 5.1 XML Namespace URN Registration . . . . . . . . . . . . . . 13 5.2 S-NAPTR Registration . . . . . . . . . . . . . . . . . . . 13 5.3 BEEP Registration . . . . . . . . . . . . . . . . . . . . 13 6. Security Considerations . . . . . . . . . . . . . . . . . . . 14 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 7.1 Normative References . . . . . . . . . . . . . . . . . . . . 15 7.2 Informative References . . . . . . . . . . . . . . . . . . . 16 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 17 Intellectual Property and Copyright Statements . . . . . . . . 18 Newton Expires April 8, 2005 [Page 2] Internet-Draft iris-dchk October 2004 1. Introduction This document describes a lightweight service for checking the availability of domain names. This service is based on the IRIS framework and uses the data model defined by DREG. By doing this, the domain availability service has the advantages provided by IRIS and DREG, such as well-known methods for server navigation, structured queries and results, and layered extensibility. The use of IRIS for this service also allows seemless integration between the domain availability service and the service provided by DREG. This allows a user to find the availability status of domain and reference the full registration information in DREG. The data model in this service (called a registry schema in IRIS terms) is a strict subset of the DREG data model. This enables implementors to directly reuse DREG code paths and allows operators to deploy the service in either the same server processes as a DREG service (same host and port) or in a different server process (different port) or machine (different host). As an example, an operator may wish to deploy both types of service on the same set of machines. As time goes on, the operator may then decide to segregate the services, placing the domain availability service on one set of machines and the DREG service on a separate set of machines with a stricter set of controls. Either deployment scenario is transparent to the end user and always appear to be seemlessly complementary. When coupled with [20], this domain availability service is lightweight and extremely effecient for high-volume, public-facing service. Newton Expires April 8, 2005 [Page 3] Internet-Draft iris-dchk October 2004 2. Document 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 [12]. Newton Expires April 8, 2005 [Page 4] Internet-Draft iris-dchk October 2004 3. DCHK Registry The data model used for the domain availability check (DCHK) service is a strict subset of the DREG data model. This section describes the DCHK registry type. See [5]. 3.1 Schema Description References to XML elements with no namespace qualifier are from the schema defined in Section 3.2. References to elements and attributes with the "iris" XML namespace qualifier are from the schema defined in IRIS [5]. The descriptions contained within this section refer to XML elements and attributes and their relation to the exchange of data within the protocol. These descriptions also contain specifications outside the scope of the formal XML syntax. Therefore, this section will use terms defined by RFC 2119 [12] to describe the specification outside the scope of the formal XML syntax. While reading this section, please reference Section 3.2 for needed details on the formal XML syntax. 3.1.1 The Result An example of a result: example.com The result represents an instance of a domain assignment. The children of the element are as follows: o - the full name of the domain as it is in DNS. The contents of this element MUST be a domain name as specified by RFC 1035 [11]. o - the name of the domain in nameprep form if applicable. See RFC 3491 [17]. o - may contain at least one of the following elements of type 'domainStatusType' (see Section 3.1.1.1), but none of these elements may appear more than once. * - permanently inactive * - normal state * - registration assigned but delegation inactive Newton Expires April 8, 2005 [Page 5] Internet-Draft iris-dchk October 2004 * - dispute * - database purge pending * - change of authority pending * - on hold by registry * - on hold by registrar o - contains an entity reference, the referent of which MUST be a (Section 3.1.1). o - an element containing an entity reference, the referent of which MUST be a (Section 3.1.1). The intention of this element is to point to the downstream registration reference. Therefore, if this is a result given back by a domain registry, it should point to the domain in the domain registrar or registrant service. o - an element containing an entity reference specifying a referent that is indirectly associated with this domain. 3.1.1.1 Domain Status Type Each element that is of the 'domainStatusType' may have an optional element and one or more elements, the text contents of which may be used to describe the status in natural language. Each element must have a 'language' attribute describing the language of the description element. 3.1.2 Support for The following types of entity classes are recognized by the query of IRIS for this registry: o domain-name - the fully qualified name of a domain. This a domain name as specified by RFC 1035 [11]. Yields a (Section 3.1.1) in the response. o idn - the fully qualified name of a domain in nameprep form (see RFC 3491 [17]). Yields a (Section 3.1.1) in the response. 3.2 DCHK Formal XML Syntax This registry schema is specified in the XML Schema notation. The formal syntax presented here is a complete schema representation suitable for automated validation of an XML instance when combined with the formal schema syntax of IRIS. Domain availability check schema derived from IRIS schema Newton Expires April 8, 2005 [Page 9] Internet-Draft iris-dchk October 2004 Figure 2: dchk.xsd 3.3 BEEP Transport Compliance Though it is envisioned that a DCHK service will be deployed with a lightweight transport such as [20], it is still possible to use DCHK with the [8] transport. The use of this transport is completely at the descretion of the server operator. IRIS allows several extensions of the core capabilities. This section outlines those extensions allowable by IRIS-BEEP [8]. 3.3.1 Message Pattern This registry type uses the default message pattern as described in IRIS-BEEP [8]. 3.3.2 Server Authentication This registry type uses the default server authentication method as described in IRIS-BEEP [8]. 3.4 URI Resolution 3.4.1 Application Service Label The application service label associated with this registry type MUST be "DCHK1". This is the abbreviated form of the URN for this registry type, urn:ietf:params:xml:ns:dchk1. 3.4.2 Bottom-Up Resolution The bottom-up alternative resolution method MUST be identified as 'bottom' in IRIS URI's. The process for this resolution method differs from the direct-resolution method if the authority is only a domain name (i.e. without the port number). The process for this condition is as follows: 1. The IRIS [5] direct resolution process is tried on the domain name (e.g. "example.com" ). 2. If the direct resolution process yields no server for which a connection can be made, then the leftmost label of the domain name is removed, and the first step is repeated again (e.g. "com" ). Newton Expires April 8, 2005 [Page 10] Internet-Draft iris-dchk October 2004 3. If all the labels of the domain name are removed and no server connections have been made, then the DNS is queried for the address records corresponding to the original domain name and the port used is the well-known port for the default protocol of IRIS. 3.4.3 Top-Down Resolution The top-down alternative resolution method MUST be identified as 'top' in IRIS URI's. The process for this resolution method differs from the direct-resolution method if the authority is only a domain name (i.e. without the port number). The process for this condition is as follows: 1. The domain name is reduced to its rightmost label. This is always '.'. 2. The IRIS [5] direct resolution process is tried on the domain name. 3. If the direct resolution process yields no server for which a connection can be made, then the original label to the left of the rightmost label of the domain name is prepended, and the second step is repeated again (e.g. if "." then "com", if "com" then "example.com"). 4. If all the labels of the original domain are present and no server connections have been made, then the DNS is queried for the address records corresponding to the original domain name and the port used is the well-known port for the default protocol of IRIS. Newton Expires April 8, 2005 [Page 11] Internet-Draft iris-dchk October 2004 4. Internationalization Considerations Implementers should be aware of considerations for internationalization in IRIS [5]. This document specifies the lookup of domain names, both the traditional ASCII form and the IDN form. In addition, the social data associated with contacts may also be non-ASCII, and could contain virtually any Unicode character. The element is provided in queries that have potential to traverse such data. Clients should use these elements to indicate to the server of the target languages desired, and servers should use these elements to better enable normalization and search processes (see [21]). Clients needing to localize the data tags in this protocol should take note that localization is only needed on the names of XML elements and attributes with the exception of elements containing date and time information. The schema for this registry has been designed so that clients need not interpret the content of elements or attributes for localization, other than those elements containing date and time information. Clients should also make use of the elements provided in many of the results. Results containing data that may be in Unicode are accompanied by these elements in order to aid better presentation of the data to the user. The "dateTimePrivacyType" element type contains the XML Schema [3] data type "dateTime". The contents of this element MUST be specified using the 'Z' indicator for Coordinated Universal Time (UTC). Newton Expires April 8, 2005 [Page 12] Internet-Draft iris-dchk October 2004 5. IANA Considerations 5.1 XML Namespace URN Registration This document makes use of a proposed XML namespace and schema registry specified in XML_URN [18]. Accordingly, the following registration information is provided for the IANA: o URN/URI: * urn:ietf:params:xml:ns:dchk1 o Contact: * Andrew Newton o XML: * The XML Schema specified in Section 3.2 5.2 S-NAPTR Registration The following S-NAPTR application service label will need to be registered with IANA according to the IANA considerations defined in IRIS [5]: DCHK1 5.3 BEEP Registration The following BEEP Profile URI is to be registeried with IANA, in addition to the registration provided in IRIS-BEEP [8]. http://iana.org/beep/iris1/dchk1 Newton Expires April 8, 2005 [Page 13] Internet-Draft iris-dchk October 2004 6. Security Considerations IRIS-LWZ is intended for serving public data; it provides no in-band mechanisms for authentication or encryption. Any application that needs that must provide out of band mechanisms to provide it (e.g., IPSec), or use the IRIS protocol with an application transport that provides such capabilities (e.g. BEEP [7]. Newton Expires April 8, 2005 [Page 14] Internet-Draft iris-dchk October 2004 7. References 7.1 Normative References [1] World Wide Web Consortium, "Extensible Markup Language (XML) 1.0", W3C XML, February 1998, . [2] World Wide Web Consortium, "Namespaces in XML", W3C XML Namespaces, January 1999, . [3] World Wide Web Consortium, "XML Schema Part 2: Datatypes", W3C XML Schema, October 2000, . [4] World Wide Web Consortium, "XML Schema Part 1: Structures", W3C XML Schema, October 2000, . [5] Newton, A. and M. Sanz, "Internet Registry Information Service", draft-ietf-crisp-iris-core-05 (work in progress), January 2004. [6] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. [7] Rose, M., "The Blocks Extensible Exchange Protocol Core", RFC 3080, March 2001. [8] Newton, A. and M. Sanz, "Internet Registry Information Service (IRIS) over Blocks Extensible Exchange Protocol (BEEP)", draft-ietf-crisp-iris-beep-05 (work in progress), January 2004. [9] Hinden, R. and S. Deering, "Internet Protocol Version 6 (IPv6) Addressing Architecture", RFC 3513, April 2003. [10] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1981. [11] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [12] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, BCP 14, March 1997. [13] International Organization for Standardization, "Codes for the Newton Expires April 8, 2005 [Page 15] Internet-Draft iris-dchk October 2004 representation of names of countries, 3rd edition", ISO Standard 3166, August 1988. [14] Braden, R., "Requirements for Internet Hosts - Application and Support", STD 3, RFC 1123, October 1989. [15] International Telecommunications Union, "The International Public Telecommunication Numbering Plan", ITU-T Recommendation E.164, 1991. [16] Faltstrom, P., Hoffman, P. and A. Costello, "Internationalizing Domain Names in Applications (IDNA)", RFC 3490, March 2003. [17] Hoffman, P. and M. Blanchet, "Nameprep: A Stringprep Profile for Internationalized Domain Names (IDN)", RFC 3491, March 2003. [18] Mealling, M., "The IETF XML Registry", draft-mealling-iana-xmlns-registry-03 (work in progress), November 2001. 7.2 Informative References [19] Newton, A., "Cross Registry Internet Service Protocol (CRISP) Requirements", RFC 3707, February 2004. [20] Newton, A., "A Lightweight UDP Transport for IRIS", draft-ietf-crips-iris-lwz-00 (work in progress), Ocotober 2004. Newton Expires April 8, 2005 [Page 16] Internet-Draft iris-dchk October 2004 URIs [21] Author's Address Andrew L. Newton VeriSign, Inc. 21345 Ridgetop Circle Sterling, VA 20166 USA Phone: +1 703 948 3382 EMail: anewton@verisignlabs.com; andy@hxr.us URI: http://www.verisignlabs.com/ Newton Expires April 8, 2005 [Page 17] Internet-Draft iris-dchk October 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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