DOA over DNS
draft-durand-doa-over-dns-00

Abstract

Abstract

This document defines a DOA RR type to implement the DOA architecture over DNS.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on January 18, 2018.

Copyright Notice

Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved.

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Table of Contents

• 1. Introduction
• 2. Terminology
• 3. The DOA Resource Record
• 3.1. Description
• 3.1.1. Enterprise and Type fields
• 3.1.2. Location field
• 3.1.3. Media Type
• 3.1.4. Data
• 3.2. DOA RDATA Wire Format
• 3.3. DOA RDATA Presentation Format
• 4. Security Considerations
• 5. Privacy Considerations
• 6. Operational consideration
• 7. IANA Considerations
• 7.1. DOA Location Type Registry
• 7.2. DOA Type Registry
• 7.3. RR Type Application Template
• 8. Acknowledgements
• 9. References
• 9.1. Normative References
• 9.2. Informative References
• Authors' Addresses

1. Introduction

This document defines a DOA RR type to implement the DOA architecture over DNS. Each RR contains an object type that might be opaque and private to the producer and the consumer of the data and either the data (if small enough to fit in the RR) or a pointer on how to retrieve the actual data.

2. Terminology

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “NOT RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

3. The DOA Resource Record

3.1. Description

The Type value for the DOA RR is TBD2. The DOA RR is class independent.

The RDATA of the resource record comprises of five fields: DOA-ENTERPRISE, DOA-TYPE, DOA-MEDIA-TYPE, DOA-LOCATION and DOA-DATA.

3.1.1. Enterprise and Type fields

The DOA-ENTERPRISE and DOA-TYPE fields are combined to indicate the semantic type of the DOA record being represented by the RR. That semantic is private to the producer of data hosted on an authoritative DNS server and the application software using a DNS stub resolver to retrieve it.

The DOA-ENTERPRISE field uses values as specified in the IANA SMI Network Management Private Enterprise Codes Registry [IANA-ENTERPRISE]. An exception to that is that the reserved value of zero (0) is used to indicate that the the DOA-ENTERPRISE is not set.

Some values of DOA-TYPE are registered in an IANA registry, others are privately defined. As those private types might be used in cross-organization systems, use of the DOA-ENTERPRISE field is RECOMMENDED to disambiguate types.

3.1.2. Location field

The DOA-LOCATION field signals how the DOA-DATA field should be interpreted using the values specified in the DOA Location Type Registry Section 7.1.

The value 0 is reserved.

For the value 1 (“Local”), the DOA-DATA contains the actual DOA object.

For the value 2 (“URI”) the DOA-DATA contains a UTF-8 encoded string representing the URI from which the DOA object may be obtained.

For the value 3 (“HDL”) the DOA-DATA contains a UTF-8 encoded string representing the handle from the Handle System [RFC3650] from which the DOA object may be obtained.

Other values might be defined in the future, for example for NFS, LDAP, etc…

DNS software implementing the DOA RR type MUST NOT drop or otherwise refuse to handle the DOA RRs containing an unknown or unsupported DOA-location and MUST treat the DOA-DATA portion of the RR as an abstract opaque field.

3.1.3. Media Type

The DOA-MEDIA-TYPE field contains the Internet media type [RFC6838] for the DOA object represented by this record.

If a non-Local object is retrieved over a protocol that supports inclusion of a media type value (e.g. an HTTP Content-Type header) then the client MUST use that value (if supplied) in preference to any value specified inside this resource record. In such case, the DOA-MEDIA-TYPE MAY be set to NULL, length 0.

3.1.4. Data

The DOA-DATA field contains either the object’s data, or some form of reference specifying from where the data can be obtained, per the DOA-LOCATION field above.

3.2. DOA RDATA Wire Format

    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
 0: |                                                               |
    |                        DOA-ENTERPRISE                         |
    |                                                               |
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
 4: |                                                               |
    |                           DOA-TYPE                            |
    |                                                               |
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
 8: |         DOA-LOCATION          |         DOA-MEDIA-TYPE        |
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
10: |                                                               |
    /                  DOA-MEDIA-TYPE (continued)                   /
    /                                                               /
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    /                                                               /
    /                           DOA-DATA                            /
    /                                                               /
    +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

DOA-ENTERPRISE: a 32-bit field in network order.

DOA-TYPE: a 32-bit field in network order.

DOA-LOCATION: a single octet field.

DOA-MEDIA-TYPE: A <character-string> (see [RFC1035]). The first octet of the <character-string> contains the number of characters to follow.

DOA-DATA: A variable length blob. The length of the DOA-DATA is not contained within the wire format of the RR and must be computed from the RDLENGTH of the entire RR once other fields have been taken into account.

« TODO: is the limitation of 255 characters of the Media Type field likely to be a limitation? »

3.3. DOA RDATA Presentation Format

The DOA-ENTERPRISE field is presented as an unsigned decimal integer with range 0 - 4,294,967,295.

The DOA-TYPE field is presented as an unsigned decimal integer with range 0 - 4,294,967,295.

The DOA-LOCATION field is presented as an unsigned decimal integer with range 0 - 255.

The DOA-MEDIA-TYPE field is presented as a single <character-string>.

The DOA-DATA is presented either as a single string enclosed in double-quote (‘”’) characters, or the token # followed by an unsigned decimal integer specifying the length of the following data, to be presented as zero or more words of hexadecimal data each containing an even number of digits (c.f. [RFC3597]).

4. Security Considerations

The use of DNSSEC is encouraged to protect the integrity of the data contained in the DOA RR type.

5. Privacy Considerations

Personally identifiable information (PII) data appearing in the DOA-DATA field SHOULD be encrypted.

6. Operational consideration

Some DOA records might contain large data that is only of interest to a single party, as such, caching those records does not provide much benefits and could be considered a denial of service attack on the caching resolver infrastructure. It is thus RECOMMENDED that the TTL associated with large DOA RRs be set as small as possible to avoid caching.

7. IANA Considerations

7.1. DOA Location Type Registry

IANA are requested to create the DOA Location Type Registry with initial contents as follows:

Assignments in the 4-199 range in this registry require Expert Review.

7.2. DOA Type Registry

IANA are requested to create the DOA Type Registry with initial contents as follows:

Assignments in the 1-99,999 range in this registry require Expert Review.

7.3. RR Type Application Template

« The RRTYPE Allocation Template per RFC 6895 will be included here »

8. Acknowledgements

9. References

9.1. Normative References

9.2. Informative References

Authors' Addresses