DNS Server Selection: DNS Server Information with Assertion Token
draft-reddy-add-server-policy-selection-06
ADD WG T. Reddy
Internet-Draft McAfee
Intended status: Standards Track D. Wing
Expires: August 24, 2021 Citrix
M. Richardson
Sandelman Software Works
M. Boucadair
Orange
February 20, 2021
DNS Server Selection: DNS Server Information with Assertion Token
draft-reddy-add-server-policy-selection-06
Abstract
The document defines a mechanism that is meant to communicate DNS
resolver information to DNS clients for use as a criteria for server
selection decisions. In particular, the document defines a mechanism
for a DNS server to communicate its filtering behavior to DNS
clients. Such an information that is cryptographically signed to
attest its authenticity is used for the selection of DNS resolvers.
Typically, evaluating the filtering behavior and the signatory, DNS
clients with minimal or no human intervention can select the DNS
servers for resolving domain names.
This assertion is useful for encrypted DNS (e.g., DNS-over-TLS, DNS-
over-HTTPS, or DNS-over-QUIC) servers that are either public
resolvers or discovered in a local network.
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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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 24, 2021.
Reddy, et al. Expires August 24, 2021 [Page 1]
Internet-Draft DNS Server Info with Assertion Token February 2021
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Policy Assertion Token (PAT): Overview . . . . . . . . . . . 4
4. PAT Header . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. 'typ' (Type) Header Parameter . . . . . . . . . . . . . . 6
4.2. 'alg' (Algorithm) Header Parameter . . . . . . . . . . . 6
4.3. 'x5u' (X.509 URL) Header Parameter . . . . . . . . . . . 7
4.4. An Example of PAT Header . . . . . . . . . . . . . . . . 7
5. PAT Payload . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1. JWT Defined Claims . . . . . . . . . . . . . . . . . . . 8
5.1.1. 'iat' - Issued At Claim . . . . . . . . . . . . . . . 8
5.1.2. 'exp' - Expiration Time Claim . . . . . . . . . . . . 8
5.2. PAT Specific Claims . . . . . . . . . . . . . . . . . . . 8
5.2.1. DNS Server Identity Claims . . . . . . . . . . . . . 8
5.2.2. 'policyinfo' (Policy Information) Claim . . . . . . . 9
5.2.3. An Example . . . . . . . . . . . . . . . . . . . . . 10
6. PAT Signature . . . . . . . . . . . . . . . . . . . . . . . . 11
7. Extending PAT . . . . . . . . . . . . . . . . . . . . . . . . 12
8. Deterministic JSON Serialization . . . . . . . . . . . . . . 12
8.1. Example PAT Deterministic JSON Form . . . . . . . . . . . 13
9. Using SVCB Responses . . . . . . . . . . . . . . . . . . . . 13
10. Security Considerations . . . . . . . . . . . . . . . . . . . 14
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
11.1. Media Type Registration . . . . . . . . . . . . . . . . 15
11.1.1. Media Type Registry Contents Additions Requested . . 15
11.2. JSON Web Token Claims Registration . . . . . . . . . . . 16
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