DNS Security (DNSSEC) Hashed Authenticated Denial of Existence
RFC 5155
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RFC - Proposed Standard
(March 2008; Errata)
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Last updated |
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2020-01-21
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IETF
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plain text
html
pdf
htmlized
with errata
bibtex
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WG state
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(None)
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Document shepherd |
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No shepherd assigned
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IESG state |
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RFC 5155 (Proposed Standard)
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Consensus Boilerplate |
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Unknown
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Telechat date |
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Responsible AD |
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Mark Townsley
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Send notices to |
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(None)
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Network Working Group B. Laurie
Request for Comments: 5155 G. Sisson
Category: Standards Track R. Arends
Nominet
D. Blacka
VeriSign, Inc.
March 2008
DNS Security (DNSSEC) Hashed Authenticated Denial of Existence
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Abstract
The Domain Name System Security (DNSSEC) Extensions introduced the
NSEC resource record (RR) for authenticated denial of existence.
This document introduces an alternative resource record, NSEC3, which
similarly provides authenticated denial of existence. However, it
also provides measures against zone enumeration and permits gradual
expansion of delegation-centric zones.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Rationale . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Requirements . . . . . . . . . . . . . . . . . . . . . . . 4
1.3. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
2. Backwards Compatibility . . . . . . . . . . . . . . . . . . . 6
3. The NSEC3 Resource Record . . . . . . . . . . . . . . . . . . 7
3.1. RDATA Fields . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.1. Hash Algorithm . . . . . . . . . . . . . . . . . . . . 8
3.1.2. Flags . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.3. Iterations . . . . . . . . . . . . . . . . . . . . . . 8
3.1.4. Salt Length . . . . . . . . . . . . . . . . . . . . . 8
3.1.5. Salt . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.6. Hash Length . . . . . . . . . . . . . . . . . . . . . 9
3.1.7. Next Hashed Owner Name . . . . . . . . . . . . . . . . 9
3.1.8. Type Bit Maps . . . . . . . . . . . . . . . . . . . . 9
3.2. NSEC3 RDATA Wire Format . . . . . . . . . . . . . . . . . 9
3.2.1. Type Bit Maps Encoding . . . . . . . . . . . . . . . . 10
3.3. Presentation Format . . . . . . . . . . . . . . . . . . . 11
Laurie, et al. Standards Track [Page 1]
RFC 5155 NSEC3 March 2008
4. The NSEC3PARAM Resource Record . . . . . . . . . . . . . . . . 12
4.1. RDATA Fields . . . . . . . . . . . . . . . . . . . . . . . 12
4.1.1. Hash Algorithm . . . . . . . . . . . . . . . . . . . . 12
4.1.2. Flag Fields . . . . . . . . . . . . . . . . . . . . . 12
4.1.3. Iterations . . . . . . . . . . . . . . . . . . . . . . 13
4.1.4. Salt Length . . . . . . . . . . . . . . . . . . . . . 13
4.1.5. Salt . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2. NSEC3PARAM RDATA Wire Format . . . . . . . . . . . . . . . 13
4.3. Presentation Format . . . . . . . . . . . . . . . . . . . 14
5. Calculation of the Hash . . . . . . . . . . . . . . . . . . . 14
6. Opt-Out . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7. Authoritative Server Considerations . . . . . . . . . . . . . 16
7.1. Zone Signing . . . . . . . . . . . . . . . . . . . . . . . 16
7.2. Zone Serving . . . . . . . . . . . . . . . . . . . . . . . 17
7.2.1. Closest Encloser Proof . . . . . . . . . . . . . . . . 18
7.2.2. Name Error Responses . . . . . . . . . . . . . . . . . 19
7.2.3. No Data Responses, QTYPE is not DS . . . . . . . . . . 19
7.2.4. No Data Responses, QTYPE is DS . . . . . . . . . . . . 19
7.2.5. Wildcard No Data Responses . . . . . . . . . . . . . . 19
7.2.6. Wildcard Answer Responses . . . . . . . . . . . . . . 20
7.2.7. Referrals to Unsigned Subzones . . . . . . . . . . . . 20
7.2.8. Responding to Queries for NSEC3 Owner Names . . . . . 20
7.2.9. Server Response to a Run-Time Collision . . . . . . . 21
7.3. Secondary Servers . . . . . . . . . . . . . . . . . . . . 21
7.4. Zones Using Unknown Hash Algorithms . . . . . . . . . . . 21
7.5. Dynamic Update . . . . . . . . . . . . . . . . . . . . . . 21
8. Validator Considerations . . . . . . . . . . . . . . . . . . . 23
8.1. Responses with Unknown Hash Types . . . . . . . . . . . . 23
8.2. Verifying NSEC3 RRs . . . . . . . . . . . . . . . . . . . 23
8.3. Closest Encloser Proof . . . . . . . . . . . . . . . . . . 23
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