Network Working Group S. Josefsson Internet-Draft March 5, 2004 Expires: September 3, 2004 Domain Name System Media Types draft-josefsson-mime-dns-02 Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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 September 3, 2004. Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract This document register the media types application/dns and text/dns, in accordance with RFC 2048 [3]. The application/dns media type is used to identify data on the detached Domain Name System (DNS) format described in RFC 2540 [4]. The text/dns media type is used to identify master files as described in RFC 1035 [2]. Josefsson Expires September 3, 2004 [Page 1] Internet-Draft Domain Name System Media Types March 2004 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. MIME type registration of application/dns . . . . . . . . . . . 4 3. MIME type registration of text/dns . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 7 Normative References . . . . . . . . . . . . . . . . . . . . . . 7 Informative References . . . . . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8 Intellectual Property and Copyright Statements . . . . . . . . . 9 Josefsson Expires September 3, 2004 [Page 2] Internet-Draft Domain Name System Media Types March 2004 1. Introduction Domain Name System (DNS) information is traditionally stored in text files, so called master files or zone files. The format is described in section 5 of RFC 1035 [2]. DNS data can also be stored in a "detached" format, intended for archiving purposes, described in RFC 2540 [4]. This document register MIME media types for the two data formats, following the registration procedures described in RFC 2048 [3]. Josefsson Expires September 3, 2004 [Page 3] Internet-Draft Domain Name System Media Types March 2004 2. MIME type registration of application/dns To: ietf-types@iana.org Subject: Registration of MIME media type application/dns MIME media type name: application MIME subtype name: dns Required parameters: None. Optional parameters: None. Encoding considerations: The data format is binary, and data must be transfered unmodified. Using encodings intended for textual parts is not recommended. Security considerations: This media type identify content as being detached DNS information, as documented in RFC 2540 [4]. This data may be security relevant according to RFC 2538 [7], or secured information according to RFC 2535 [6]. Securing the content further may be done by standard techniques, such as OpenPGP [5] or CMS [8], but this is outside of the scope here. Further security assessments are not available at this point. Interoperability considerations: The encoding of detached DNS information is, unlike textual master files, well defined. No further interoperability considerations are known. Published specification: The format of data that could be tagged with this media type is documented in RFC 2540 [4]. Applications which use this media type: DNS related software, including software storing and using certificates stored in DNS. Additional information: Magic number(s): None. File extension(s): Unknown. Macintosh File Type Code(s): Unknown. Person & email address to contact for further information: Simon Josefsson simon@josefsson.org Intended usage: LIMITED USE Author/Change controller: simon@josefsson.org Josefsson Expires September 3, 2004 [Page 4] Internet-Draft Domain Name System Media Types March 2004 3. MIME type registration of text/dns To: ietf-types@iana.org Subject: Registration of MIME media type text/dns MIME media type name: text MIME subtype name: dns Required parameters: None. Optional parameters: None. Encoding considerations: The data is textual, and should be transfered in a line oriented mode. Text literals may contain CRLF within the text. Binary transports is possible between systems that use the same end-of-line conventions. Master files are in general ASCII, but non-ASCII octet values may occur and are treated as opaque values by DNS software (compare RFC 1035 section 5). The master file format permits encoding arbitrary octet values using the "\DDD" encoding. The use of "\DDD" encoding can be more reliable than transporting non-ASCII through MIME transports, if data passes through a gateway that re-encode the character data. Security considerations: This media type identify content as being DNS information in "master file" format, as documented in RFC 1035 [2]. The DNS data may be security relevant according to RFC 2538 [7], or secured information according to RFC 2535 [6]. Securing the content further may be done by standard techniques, such as OpenPGP [5] or CMS [8], but this is outside of the scope here. Further security assessments are not available at this point. Interoperability considerations: There are interoperability concerns with master files, due to the wide spread use of vendor specific extensions. Non-ASCII comments within master files may have been encoded in a locally chosen character sets, which may be difficult to transport interoperably. Non-ASCII data in general can become corrupted by re-encoding gateways. To achieve interoperability, you can use the master file format described in the specification and the "\DDD" encoding for non-ASCII octets. Published specification: The format of data that could be tagged with this MIME type is documented in RFC 1035 [2]. Applications which use this media type: DNS related software, including software storing and using certificates stored in DNS. Josefsson Expires September 3, 2004 [Page 5] Internet-Draft Domain Name System Media Types March 2004 Additional information: Magic number(s): None. File extension(s): 'soa' and 'zone' are known to be used. Macintosh File Type Code(s): Unknown. Person & email address to contact for further information: Simon Josefsson simon@josefsson.org Intended usage: LIMITED USE Author/Change controller: simon@josefsson.org Josefsson Expires September 3, 2004 [Page 6] Internet-Draft Domain Name System Media Types March 2004 4. Security Considerations Security considerations are discussed in the security considerations clause of the MIME registrations in section 2 and 3. 5. IANA Considerations The IANA is asked to register the MIME media types application/dns and text/dns using the registration templates in section 2 and 3, according to the procedure described in RFC 2048 [3]. 6. Acknowledgments Thanks to D. Eastlake for suggesting text/dns. Thanks to Keith Moore for reviewing earlier versions of this document. The author acknowledges the RSA Laboratories for supporting the work that led to this document. Normative References [1] Mockapetris, P., "Domain names - concepts and facilities", STD 13, RFC 1034, November 1987. [2] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [3] Freed, N., Klensin, J. and J. Postel, "Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures", BCP 13, RFC 2048, November 1996. [4] Eastlake, D., "Detached Domain Name System (DNS) Information", RFC 2540, March 1999. Informative References [5] Callas, J., Donnerhacke, L., Finney, H. and R. Thayer, "OpenPGP Message Format", RFC 2440, November 1998. [6] Eastlake, D., "Domain Name System Security Extensions", RFC 2535, March 1999. [7] Eastlake, D. and O. Gudmundsson, "Storing Certificates in the Domain Name System (DNS)", RFC 2538, March 1999. [8] Housley, R., "Cryptographic Message Syntax (CMS)", RFC 3369, August 2002. Josefsson Expires September 3, 2004 [Page 7] Internet-Draft Domain Name System Media Types March 2004 Author's Address Simon Josefsson EMail: simon@josefsson.org Josefsson Expires September 3, 2004 [Page 8] Internet-Draft Domain Name System Media Types March 2004 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. 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