DNS Server Selection: DNS Server Information with Assertion Token
draft-reddy-add-server-policy-selection-05
ADD WG T. Reddy
Internet-Draft McAfee
Intended status: Standards Track D. Wing
Expires: March 4, 2021 Citrix
M. Richardson
Sandelman Software Works
M. Boucadair
Orange
August 31, 2020
DNS Server Selection: DNS Server Information with Assertion Token
draft-reddy-add-server-policy-selection-05
Abstract
The document defines a mechanism that allows communication of DNS
resolver information to DNS clients for use in server selection
decisions. In particular, the document defines a mechanism for a DNS
server to communicate its filtering policy and privacy statement URL
to DNS clients. This information is cryptographically signed to
attest its authenticity. Such information is used for the selection
of DNS resolvers. Typically, evaluating the DNS privacy statement,
filtering policy, and the signatory, DNS clients with minimum human
intervention can select the DNS server that best supports the user's
desired privacy and filtering policy.
This assertion is useful for encrypted DNS (e.g., DNS-over-TLS, DNS-
over-HTTPS, DNS-over-QUIC) servers that are either public resolvers
or discovered in a local network.
Status of This Memo
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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 March 4, 2021.
Reddy, et al. Expires March 4, 2021 [Page 1]
Internet-Draft DNS Server Info with Assertion Token August 2020
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Sample Use Cases . . . . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Policy Assertion Token (PAT): Overview . . . . . . . . . . . 6
5. PAT Header . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1. 'typ' (Type) Header Parameter . . . . . . . . . . . . . . 7
5.2. 'alg' (Algorithm) Header Parameter . . . . . . . . . . . 8
5.3. 'x5u' (X.509 URL) Header Parameter . . . . . . . . . . . 8
5.4. An Example of PAT Header . . . . . . . . . . . . . . . . 8
6. PAT Payload . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1. JWT Defined Claims . . . . . . . . . . . . . . . . . . . 9
6.1.1. 'iat' - Issued At Claim . . . . . . . . . . . . . . . 9
6.1.2. 'exp' - Expiration Time Claim . . . . . . . . . . . . 9
6.2. PAT Specific Claims . . . . . . . . . . . . . . . . . . . 9
6.2.1. DNS Server Identity Claims . . . . . . . . . . . . . 10
6.2.2. 'policyinfo' (Policy Information) Claim . . . . . . . 10
6.2.3. Example . . . . . . . . . . . . . . . . . . . . . . . 12
7. PAT Signature . . . . . . . . . . . . . . . . . . . . . . . . 12
8. Extending PAT . . . . . . . . . . . . . . . . . . . . . . . . 13
9. Deterministic JSON Serialization . . . . . . . . . . . . . . 13
9.1. Example PAT Deterministic JSON Form . . . . . . . . . . . 14
10. Using RESINFO responses . . . . . . . . . . . . . . . . . . . 14
11. Privacy Considerations . . . . . . . . . . . . . . . . . . . 15
12. Security Considerations . . . . . . . . . . . . . . . . . . . 16
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
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