7Internet Engineering Task Force (IETF) O. Gudmundsson
8Request for Comments: 7218 Shinkuro Inc.
9Updates: 6698 April 2014
10Category: Standards Track
14 Adding Acronyms to Simplify Conversations about
15 DNS-Based Authentication of Named Entities (DANE)
19 Experience has shown that people get confused when discussing the
20 three numeric fields of the TLSA record. This document specifies
21 descriptive acronyms for the three numeric fields in TLSA records.
22 This document updates the format of the IANA registry created by RFC
27 This is an Internet Standards Track document.
29 This document is a product of the Internet Engineering Task Force
30 (IETF). It represents the consensus of the IETF community. It has
31 received public review and has been approved for publication by the
32 Internet Engineering Steering Group (IESG). Further information on
33 Internet Standards is available in Section 2 of RFC 5741.
35 Information about the current status of this document, any errata,
36 and how to provide feedback on it may be obtained at
37 http://www.rfc-editor.org/info/rfc7218.
41 Copyright (c) 2014 IETF Trust and the persons identified as the
42 document authors. All rights reserved.
44 This document is subject to BCP 78 and the IETF Trust's Legal
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46 (http://trustee.ietf.org/license-info) in effect on the date of
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49 to this document. Code Components extracted from this document must
50 include Simplified BSD License text as described in Section 4.e of
51 the Trust Legal Provisions and are provided without warranty as
52 described in the Simplified BSD License.
58Gudmundsson Standards Track [Page 1]
60RFC 7218 Adding Acronyms to DANE Registries April 2014
65 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
66 2. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 2
67 2.1. TLSA Certificate Usages Registry . . . . . . . . . . . . 3
68 2.2. TLSA Selectors . . . . . . . . . . . . . . . . . . . . . 3
69 2.3. TLSA Matching Types . . . . . . . . . . . . . . . . . . . 4
70 3. Examples of Usage . . . . . . . . . . . . . . . . . . . . . . 4
71 3.1. TLSA Records Using/Displaying the Acronyms . . . . . . . 4
72 3.2. Acronym Use in a Specification Example . . . . . . . . . 4
73 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
74 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
75 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
76 6.1. Normative References . . . . . . . . . . . . . . . . . . 5
77 6.2. Informative References . . . . . . . . . . . . . . . . . 5
81 During discussions on how to add DNS-Based Authentication of Named
82 Entities (DANE) [RFC6698] technology to new protocols and services,
83 people were repeatedly confused as to what the numeric values stood
84 for and even the order of the fields of a TLSA record (note that TLSA
85 is not an acronym but a name). This document updates the IANA
86 registry definition for the TLSA record to add a column containing an
87 acronym for each specified field, in order to reduce confusion. This
88 document does not change the DANE protocol in any way.
90 It is expected that DANE parsers in applications and DNS software can
91 adopt parsing the acronyms for each field.
95 This document applies to the "DNS-Based Authentication of Named
96 Entities (DANE) Parameters" registry located at <http://www.iana.org/
97 assignments/dane-parameters>. IANA has added a column with an
98 acronym to each of the sub-registries.
100 [RFC6698] and this document are the referenced documents for the
101 three sub-registries.
103 As these acronyms are offered for human consumption, case does not
104 matter; it is expected that software that parses TLSA records will
105 handle upper-, mixed-, or lower-case characters as input.
114Gudmundsson Standards Track [Page 2]
116RFC 7218 Adding Acronyms to DANE Registries April 2014
1192.1. TLSA Certificate Usages Registry
121 The reference for this registry has been updated to include both
122 [RFC6698] and this document.
124 +-------+----------+--------------------------------+-------------+
125 | Value | Acronym | Short Description | Reference |
126 +-------+----------+--------------------------------+-------------+
127 | 0 | PKIX-TA | CA constraint | [RFC6698] |
128 | 1 | PKIX-EE | Service certificate constraint | [RFC6698] |
129 | 2 | DANE-TA | Trust anchor assertion | [RFC6698] |
130 | 3 | DANE-EE | Domain-issued certificate | [RFC6698] |
131 | 4-254 | | Unassigned | |
132 | 255 | PrivCert | Reserved for Private Use | [RFC6698] |
133 +-------+----------+--------------------------------+-------------+
135 Table 1: TLSA Certificate Usages
139 The reference for this registry has been updated to include both
140 [RFC6698] and this document.
142 +-------+---------+--------------------------+-------------+
143 | Value | Acronym | Short Description | Reference |
144 +-------+---------+--------------------------+-------------+
145 | 0 | Cert | Full certificate | [RFC6698] |
146 | 1 | SPKI | SubjectPublicKeyInfo | [RFC6698] |
147 | 2-254 | | Unassigned | |
148 | 255 | PrivSel | Reserved for Private Use | [RFC6698] |
149 +-------+---------+--------------------------+-------------+
151 Table 2: TLSA Selectors
170Gudmundsson Standards Track [Page 3]
172RFC 7218 Adding Acronyms to DANE Registries April 2014
1752.3. TLSA Matching Types
177 The reference for this registry has been updated to include both
178 [RFC6698] and this document.
180 +-------+-----------+--------------------------+-------------+
181 | Value | Acronym | Short Description | Reference |
182 +-------+-----------+--------------------------+-------------+
183 | 0 | Full | No hash used | [RFC6698] |
184 | 1 | SHA2-256 | 256 bit hash by SHA2 | [RFC6234] |
185 | 2 | SHA2-512 | 512 bit hash by SHA2 | [RFC6234] |
186 | 3-254 | | Unassigned | |
187 | 255 | PrivMatch | Reserved for Private Use | [RFC6698] |
188 +-------+-----------+--------------------------+-------------+
190 Table 3: TLSA Matching Types
194 Two examples are described below.
1963.1. TLSA Records Using/Displaying the Acronyms
198 _666._tcp.first.example. TLSA PKIX-TA CERT SHA2-512 {blob}
199 _666._tcp.second.example. TLSA DANE-TA SPKI SHA2-256 {blob}
2013.2. Acronym Use in a Specification Example
203 Protocol FOO only allows TLSA records using PKIX-EE and DANE-EE, with
204 selector SPKI, and using SHA2-512.
2064. Security Considerations
208 This document only changes registry fields and does not change the
209 behavior of any protocol. The hope is to reduce confusion, which
210 would lead to better specification and operations.
214 Scott Schmit offered really good suggestions to decrease the
215 possibility of confusion. Viktor Dukhovni provided comments from the
216 expert point of view. Jim Schaad, Wes Hardaker, and Paul Hoffman
217 provided feedback during WGLC. Dan Romascanu and Tobias Gondrom
218 pointed out a few defects during the IESG last call.
226Gudmundsson Standards Track [Page 4]
228RFC 7218 Adding Acronyms to DANE Registries April 2014
2336.1. Normative References
235 [RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
236 of Named Entities (DANE) Transport Layer Security (TLS)
237 Protocol: TLSA", RFC 6698, August 2012.
2396.2. Informative References
241 [RFC6234] Eastlake, D. and T. Hansen, "US Secure Hash Algorithms
242 (SHA and SHA-based HMAC and HKDF)", RFC 6234, May 2011.
248 4922 Fairmont Av, Suite 250
282Gudmundsson Standards Track [Page 5]