CDNI Working Group F. Fieau, Ed. Internet-Draft E. Stephan Intended status: Standards Track Orange Expires: 12 January 2023 S. Mishra Verizon 11 July 2022 CDNI extensions for HTTPS delegation draft-ietf-cdni-interfaces-https-delegation-09 Abstract This document defines a new Footprint and Capabilities metadata objects to support HTTPS delegation between two or more interconnected CDNs. Specifically, this document outlines CDNI Metadata interface objects for delegation method as published in the ACME-STAR document [RFC9115]. 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/. 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Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Delegation metadata for CDNI FCI . . . . . . . . . . . . . . 3 4. Delegation metadata for CDNI . . . . . . . . . . . . . . . . 4 4.1. Usage example related to an HostMatch object . . . . . . 4 4.2. AcmeStarDelegationMethod object . . . . . . . . . . . . . 5 5. IANA considerations . . . . . . . . . . . . . . . . . . . . . 6 5.1. CDNI MI AcmeStarDelegationMethod Payload Type . . . . . . 7 5.2. CDNI FCI SupportedDelegationMethods Payload Type . . . . 7 6. Security considerations . . . . . . . . . . . . . . . . . . . 7 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.1. Normative References . . . . . . . . . . . . . . . . . . 7 7.2. Informative References . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction Content delivery over HTTPS using one or more CDNs along the path requires credential management. This specifically applies when an entity delegates delivery of encrypted content to another trusted entity. [RFC9115] defines a mechanism where an upstream entity, that is, holder of a X.509 certificate can give a temporary delegated authority, via issuing a certificate to one or more downstream entities for the purposes of delivering content on its behalf. Furthermore, the upstream entity has the ability to extend the duration of the certificate automatically and iteratively until it allows the last renewal to end and therefore terminate the use of certificate authority to the downstream entity. Fieau, et al. Expires 12 January 2023 [Page 2] Internet-Draft CDNI extensions for HTTPS delegation July 2022 More specifically, [RFC9115] defines a process where the upstream Content Delivery Network (uCDN), the holder of the domain, generates on-demand a X.509 certificate for the downstream CDN (dCDN). The certificate generation process ensures that the certified public key corresponds to a private key controlled by the downstream CDN. [RFC9115] follows [RFC8739] for Short-Term, Automatically Renewed Certificate (STAR) in the Automated Certificate Management Environment (ACME). This document defines CDNI Metadata to make use of HTTPS delegation between an upstream CDN (uCDN) and a downstream CDN (dCDN) based on mechanism specified in [RFC9115]. Furthermore, it includes a proposal of IANA registry to enable adding of delegation methods. Section 2 defines terminology used in this document. Section 3 presents delegation metadata for the FCI interface. Section 4 addresses the metadata for handling HTTPS delegation with the Metadata Interface. Section 5 addresses IANA registry for delegation methods. Section 6 covers the security considerations. 2. Terminology This document uses terminology from CDNI framework documents such as: CDNI framework document [RFC7336], CDNI requirements [RFC7337] and CDNI interface specifications documents: CDNI Metadata interface [RFC8006] and CDNI Footprint and capabilities [RFC8008]. 3. Delegation metadata for CDNI FCI The Footprint and Capabilities interface as defined in [RFC8008], allows a dCDN to send a FCI capability type object to a uCDN. This draft adds an object named FCI.SupportedDelegationMethods. This object shall allow a dCDN to advertise the capabilities regarding the supported delegation methods and their configuration. The following is an example of the supported delegated methods capability object for a CDN supporting STAR delegation method. Fieau, et al. Expires 12 January 2023 [Page 3] Internet-Draft CDNI extensions for HTTPS delegation July 2022 { "capabilities": [ { "capability-type": "FCI.SupportedDelegationMethods", "capability-value": { "delegation-methods": [ "AcmeStarDelegationDelegationMethod", "... Other supported delegation methods ..." ] } "footprints": [ ] } ] } 4. Delegation metadata for CDNI This section defines Delegation metadata using the current Metadata interface model. This allows bootstrapping delegation methods between a uCDN and a delegate dCDN. 4.1. Usage example related to an HostMatch object This section presents the use of CDNI Delegation metadata to apply to an HostMatch object, as defined in [RFC8006] and as specified in the following sections. The existence of delegation method in the CDNI metadata Object shall enable the use of this method, as chosen by the delegating entity. In the case of an HostMatch object, the delegation method will be activated for the set of Host defined in the HostMatch. See Section 4.2 for more details about delegation methods metadata specification. The HostMatch object can reference a host metadata that points at the delegation information. Delegation metadata are added to a Metadata object. Those "delegation" metadata can apply to other MI objects such as PathMatch object metadata. Below shows both HostMatch and its Metadata related to a host, for example, here is a HostMatch object referencing "video.example.com": Fieau, et al. Expires 12 January 2023 [Page 4] Internet-Draft CDNI extensions for HTTPS delegation July 2022 HostMatch: { "host": "video.example.com", "host-metadata": { "type": "MI.HostMetadata", "href": "https://metadata.ucdn.example/host1234" } } Following the example above, the metadata is modeled for ACMEStarDelegationMethod as follows: "generic-metadata-value": { "acme-delegations": [ "https://acme.ucdn.example/acme/delegation/ogfr8EcolOT", "https://acme.ucdn.example/acme/delegation/wSi5Lbb61E4" ] } 4.2. AcmeStarDelegationMethod object This section defines the AcmeStarDelegationMethod object which describes metadata related to the use of ACME/STAR API presented in [RFC9115] As expressed in [RFC9115], when an origin has set a delegation to a specific domain (i.e. dCDN), the dCDN should present to the end-user client, a short-term certificate bound to the master certificate. Fieau, et al. Expires 12 January 2023 [Page 5] Internet-Draft CDNI extensions for HTTPS delegation July 2022 dCDN uCDN Content Provider CA | ACME/STAR proxy ACME/STAR client ACME/STAR srv | | | | | 1. GET Metadata incl. Delegation Method object with CSR template| +-------------------->| | | | 200 OK + Metadata incl. CSR template [CDNI] | |<--------------------+ | | | 2. Request delegation: video.dcdn.example + dCDN public key | +-------------------->| | | | | 3. Request STAR Cert + dCDN public key | | +-------------------->| 4. Request STAR cert| | | | + Pubkey | | | |-------------------->| | | | 5. STAR certificate | | | 6. STAR certificate |<--------------------| | 7. STAR certificate |<--------------------+ | +<--------------------| | | | | | | | 8. Retrieve STAR certificate (credential-location-uri) | +---------------------------------------------------------------->| | | | 9. renew +--| | | | cert | | | 10. Star certificate | +->| |<----------------------------------------------------------------+ | ... | | | Figure 1: Example call-flow of STAR delegation in CDNI showing 2 levels of delegation Property: acme-delegations Description: an array of delegation objects associated with the dCDN account on the uCDN ACME server (see Section 2.3.1 of [RFC9115] for the details). Type: Objects Mandatory-to-Specify: Yes 5. IANA considerations This document requests the registration of the following entries under the "CDNI Payload Types" registry hosted by IANA regarding "CDNI delegation": Fieau, et al. Expires 12 January 2023 [Page 6] Internet-Draft CDNI extensions for HTTPS delegation July 2022 +-------------------------------+---------------+ | Payload Type | Specification | +-------------------------------+---------------+ | MI.AcmeStarDelegationMethod | RFCthis | +-------------------------------+---------------+ | FCI.SupportedDelegationMethods| RFCthis | +-------------------------------+---------------+ [RFC Editor: Please replace RFCthis with the published RFC number for this document.] 5.1. CDNI MI AcmeStarDelegationMethod Payload Type Purpose: The purpose of this Payload Type is to distinguish AcmeStarDelegationMethod MI objects (and any associated capability advertisement) Interface: MI Encoding: see Section 5 5.2. CDNI FCI SupportedDelegationMethods Payload Type Purpose: The purpose of this Payload Type is to distinguish SupportedDelegationMethods FCI objects (and any associated capability advertisement) Interface: FCI Encoding: see Section 4 6. Security considerations Delegation metadata proposed here do not alter nor change Security Considerations as outlined in the following RFCs: An Automatic Certificate Management Environment (ACME) Profile for Generating Delegated Certificates [RFC9115]; the CDNI Metadata [RFC8006] and CDNI Footprint and Capabilities [RFC8008]. 7. References 7.1. Normative References Fieau, et al. Expires 12 January 2023 [Page 7] Internet-Draft CDNI extensions for HTTPS delegation July 2022 [RFC8006] Niven-Jenkins, B., Murray, R., Caulfield, M., and K. Ma, "Content Delivery Network Interconnection (CDNI) Metadata", RFC 8006, DOI 10.17487/RFC8006, December 2016, . [RFC8008] Seedorf, J., Peterson, J., Previdi, S., van Brandenburg, R., and K. Ma, "Content Delivery Network Interconnection (CDNI) Request Routing: Footprint and Capabilities Semantics", RFC 8008, DOI 10.17487/RFC8008, December 2016, . [RFC8739] Sheffer, Y., Lopez, D., Gonzalez de Dios, O., Pastor Perales, A., and T. Fossati, "Support for Short-Term, Automatically Renewed (STAR) Certificates in the Automated Certificate Management Environment (ACME)", RFC 8739, DOI 10.17487/RFC8739, March 2020, . [RFC9115] Sheffer, Y., López, D., Pastor Perales, A., and T. Fossati, "An Automatic Certificate Management Environment (ACME) Profile for Generating Delegated Certificates", RFC 9115, DOI 10.17487/RFC9115, September 2021, . 7.2. Informative References [RFC7336] Peterson, L., Davie, B., and R. van Brandenburg, Ed., "Framework for Content Distribution Network Interconnection (CDNI)", RFC 7336, DOI 10.17487/RFC7336, August 2014, . [RFC7337] Leung, K., Ed. and Y. Lee, Ed., "Content Distribution Network Interconnection (CDNI) Requirements", RFC 7337, DOI 10.17487/RFC7337, August 2014, . Authors' Addresses Frederic Fieau (editor) Orange 40-48, avenue de la Republique 92320 Chatillon France Email: frederic.fieau@orange.com Fieau, et al. Expires 12 January 2023 [Page 8] Internet-Draft CDNI extensions for HTTPS delegation July 2022 Emile Stephan Orange 2, avenue Pierre Marzin 22300 Lannion France Email: emile.stephan@orange.com Sanjay Mishra Verizon 13100 Columbia Pike Silver Spring, MD 20904 United States of America Email: sanjay.mishra@verizon.com Fieau, et al. Expires 12 January 2023 [Page 9]