Internet Engineering Task Force M. Zhang Internet-Draft December 25, 2020 Intended status: Informational Expires: June 28, 2021 Discussion of Requirements for ADD draft-zhang-add-requirement-discusses-00 Abstract This document discusses various usage scenarios and corresponding requirements for discovering and using encrypted DNS technology. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on June 28, 2021. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Zhang Expires June 28, 2021 [Page 1] Internet-Draft Discussion of Requirements for ADD December 2020 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions Used in This Document . . . . . . . . . . . . . . 2 3. Discover and use of encrypted DNS services . . . . . . . . . 2 3.1. The client automatically obtains DNS resolution service . 3 3.2. The client has been configured with parameters . . . . . 3 3.3. Configuration examples . . . . . . . . . . . . . . . . . 3 4. Encrypted DNS resolution service list . . . . . . . . . . . . 4 4.1. Provide a public encrypted DNS resolution service address list . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.2. Provide encrypted DNS resolution configuration for some specific domain names . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4 7. Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . 4 8. Informative References . . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction Several DNS encryption technologies have been introduced, including DNS-over-TLS and DNS-over-HTTPS and so on. The work of the Adaptive DNS Discovery working group includes supporting client discovery of encrypted DNS resolution services and communication mechanisms for selection decisions. Since the proposal of the draft plan should be guided by the existing problems, the working group should first reach a consensus on the problems to be solved and the principles applicable to each problem, and then promote follow-up work on this basis. This document discusses various usage scenarios and corresponding requirements for discovering and using encrypted DNS technology. 2. Conventions Used in This Document Encrypted DNS: DNS-over-HTTPS[RFC8484], DNS-over-TLS[RFC7858] or any other encrypted DNS technology that the IETF may publish, for example, DNS-over-QUIC [I-D.ietf-dprive-dnsoquic]. 3. Discover and use of encrypted DNS services The DNS client accesses the recursive server with discovery function, and the discussion is divided into the following situations: Zhang Expires June 28, 2021 [Page 2] Internet-Draft Discussion of Requirements for ADD December 2020 3.1. The client automatically obtains DNS resolution service 1) Ordinary DNS resolution service The client can automatically obtain the common DNS recursive resolution server address through DHCP. 2) Encrypted DNS resolution service The client can choose several types of encryption resolution services currently provided (such as DOH/DOT, etc.), and accept the default configuration of the recursive server. The encrypted DNS recursive resolution server address can be automatically set through DHCP/RA/PPP and other protocols. 3.2. The client has been configured with parameters If the client has been configured with parameters, the following two aspects are initially considered for configuration parameters: 1) For general DNS resolution services, the client can update and configure the encrypted DNS recursive resolution server type and address. This method is suitable for common networks and specific networks. 2) Users can set to use the specified encrypted DNS resolution service when accessing certain specific domain names. Set up a list of mapping relationships between domain names and DNS resolution service addresses. 3.3. Configuration examples *Normal DNS resolution (single choice) -Obtain DNS server address automatically (single choice) -Use the following DNS server address (single choice) First choice: ____._____.____.____ Alternative: ____._____.____.____ *Encrypted DNS resolution (single choice) -Type: DOT/DOH -Obtain DNS server address automatically (single choice) -Use the following encrypted DNS server address (single choice) First choice: ____._____.____.____ Alternative: ____._____.____.____ Zhang Expires June 28, 2021 [Page 3] Internet-Draft Discussion of Requirements for ADD December 2020 Domain name Type Address www.google.com DOT xxx.xxx.xxx.xxx 4. Encrypted DNS resolution service list 4.1. Provide a public encrypted DNS resolution service address list We can provide an encrypted DNS recursive resolution server address list, which can be publicly maintained and updated regularly. The priority of selecting an encrypted DNS resolver is determined by the server's own design. Currently Mozilla maintains a similar list relationship. 4.2. Provide encrypted DNS resolution configuration for some specific domain names If some companies or institutions want to use their own encrypted DNS resolution service when accessing their own domain names, they will provide the resolution server through the mapping relationship. 5. IANA Considerations To be added. 6. Security Considerations To be added. 7. Acknowledgment The authors would like to thank Jiankang Yao, and Linlin Zhou for their careful review and valuable comments. 8. Informative References [I-D.ietf-dprive-dnsoquic] Huitema, C., Mankin, A., and S. Dickinson, "Specification of DNS over Dedicated QUIC Connections", draft-ietf- dprive-dnsoquic-01 (work in progress), October 2020. [RFC7858] Hu, Z., Zhu, L., Heidemann, J., Mankin, A., Wessels, D., and P. Hoffman, "Specification for DNS over Transport Layer Security (TLS)", RFC 7858, DOI 10.17487/RFC7858, May 2016, . Zhang Expires June 28, 2021 [Page 4] Internet-Draft Discussion of Requirements for ADD December 2020 [RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS (DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018, . Author's Address Man Zhang 4 South 4th Street, Zhongguancun, Haidian District Beijing, Beijing 100190 China Email: zhangman@cnnic.cn Zhang Expires June 28, 2021 [Page 5]