NASR C. Liu Internet-Draft Huawei Intended status: Informational M. Chen Expires: 8 January 2025 China Mobile M. Richardson Sandelman Software Works D. Lopez Telefonica 7 July 2024 Network Attestation for Secure Routing (NASR) Architecture draft-liu-nasr-architecture-00 Abstract This document provides an architecture overview of NASR entities, interactive procedures and messages. 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 8 January 2025. Copyright Notice Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved. Liu, et al. Expires 8 January 2025 [Page 1] Internet-Draft NASR-Architecture July 2024 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 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. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Architectural Overview . . . . . . . . . . . . . . . . . . . 3 4.1. Single client - single operator (An Oversimplification) . . . . . . . . . . . . . . . . . . . 3 4.2. Multi Client - Multi Operator . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 7. Informative References . . . . . . . . . . . . . . . . . . . 8 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 1. Introduction Endpoints typically perceives no information of the properties of the paths over which their traffic is carried, especially when the properties are security-related. Therefore, data security (confidentiality, integrity and authenticity) has been insofar primarily protected by traffic signing and encryption mechanisms. Endpoint cannot choose devices with specific properties to bear transmission. However, clients with high security and privacy requirements are not anymore satisfied with traffic signing and encryption mechanisms only; they now request information of the trustworthiness or security properties of the network paths over which the traffic is carried, preferably to choose the desired properties. For example, some clients may require their data to traverse through trusted devices and trusted links only, in order to avoid data being exposed to insecure devices, causing leakage. Liu, et al. Expires 8 January 2025 [Page 2] Internet-Draft NASR-Architecture July 2024 Remote Attestation Procedures (RATS) working group developed procedures to establish a level of confidence in the trustworthiness of a device or a system. RATS provide 1. objective, appraisable evidence of a device’s trust or security properties, and 2. verifiable integrity proof to the evidence (Attestation Result). Devices with integrity proof are expected to function correctly and deterministically, as anticipated. Following the same RATS philosophy and building on top of it, Network Attestation for Secure Routing （NASR) aims at a solution specifically designed for the routing use case. NASR aims to provide 1. objective, appraisable evidence of a routing path’s trust or security properties, 2. verifiable integrity proof in the path-level, and 3. verifiable proof that certain packets/flows traveled such paths. Altogether, the NASR goal is to 1. Allow clients to choose desired security attributes of his received network service, 2. Achieve dependable forwarding by routing on top of only devices that satisfies certain trust requirements, and 3. prove to the clients that certain packets or flows traversed a network path that has certain trust or security properties. This document introduces the architecture, entities, interactive procedures, and messages sent between the entities, so to achieve the NASR objective. 2. Use Cases Please refer to the use cases identified in [I-D.liu-nasr-requirements-01] 3. Terminology Please refer to the terminologies identified in [I-D.richardson-nasr-terminology-01]. Terminology from RATS Architecture document [RFC9344] also applies. NASR will leverage RATS implementations and specifications, including but not limited to [I-D.ietf-rats-ar4si-06][I-D.ietf-rats-corim-04]. 4. Architectural Overview 4.1. Single client - single operator (An Oversimplification) Liu, et al. Expires 8 January 2025 [Page 3] Internet-Draft NASR-Architecture July 2024 +--------------------+ | | | Relying Party | | | | | +----+---------^-----+ Path | | Request| | Report | | +----v---------+-----+ +--------------------+ | | Path Attestation Result (PAR) | | | Orchestrator | | Verifier | | <------------------------------------+ | | | | | +----+---------------+ +----------^---------+ | | Path | | Path Evidence | | Evidence (PE) | | (PE) +----v---------------+ +--------------------+ +----------+---------+ | | | | | | | Attester +-------> Attester... +-------> Attester | | | | | | | +--------------------+ +--------------------+ +--------------------+ Update PE with Update PE with AR/RE/PoT AR/RE/PoT Figure 1. NASR Architecture-- Oversimplified Fig. 1 is an oversimplification to ease understanding of the concept. In a single client - single operator scenario, a client (Relying Party) sends a Path Request containing his security or trustworthiness requirements of a leased line. The Orchestrator, run by the operator, would choose qualifying devices (Attesters) and send out an empty Path Evidence inquiry. The Attesters update the Path Evidence with its own Raw Evidence or Attestation Results one-by-one. The Verifier verifies the filled Path Evidence, produce a Path Attestation Result (PAR), and sends it back to the Relying Party. The Relying Party now have confidence over the trustworthiness of received network. After the end-to-end service is delivered, during service, Proof-of-Transits are also created by each Attester, being sent in-band accumulatively or out-of-band, to detect unexpected routing deviation. This process is repeated periodically to continuously assure compliance. 4.2. Multi Client - Multi Operator Liu, et al. Expires 8 January 2025 [Page 4] Internet-Draft NASR-Architecture July 2024 ┌────────────────────────────────────────────────────────────────┐ │ │ │ ┌────────────┐ ┌────────────┐ │ │ │ Verifier │ │ Verifier │ ... │ │ │ Vendor A │ │ Vendor B │ │ ┌───────────────────┐ │ └────▲─────┬─┘ └───▲────┬───┘ Vendors │ ┌───────────────────┐ │ │ │ │ │ │ │ │ │ │ │ │ └────────────┼─────┼───────────────────────┼────┼────────────────┘ │ │ │ Client A │ │ │ │ │ │ Client B │ │ │ Path │ │ │ │ Path │ │ │ ┌──────────────┐ │ Request │ │ │ │ Attestation │ ┌────────────┐ │ │ │ Relying ├─┼──────────┐ ┌─────┼─────┼───────┐ ┌──────┼────┼───────┐ Result (PAR)│ │ Relying │ │ │ │ Party │ │ │ │ │ │ │ │ │ │ │ ┌───────┼───┤ Party │ │ │ └───┬──────────┘◄├────────┐ │ │ │ │ │ Intra │ │ │ │ │ │ └────────────┘ │ │ │ │ │ │ │ RE │ │AR │ ISP │ RE │ │ AR │ │ │ ▲ │ │ │ │ Answer │ └─► ┌───┴─────▼─────┐ │ API │ ┌───┴────▼────┐ │ │ │ │ │ │ │Path │ Report │ │ │ Orchestrator ├─┼────────┼─►│ Orchestrator│◄─┼─────┘ │ │ │ │ │Evidence │ └───┤ └───▲─────┬─────┘ │ │ └───▲────┬────┘ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ RE │ │AR │ │ RE │ │ AR │ │ │ │ │ ┌──▼────────┐ │ │ ┌───┴─────▼─────┐ │ │ ┌───┴────▼─────┐ │ │ ┌───────┴───┐ │ │ │ Attester │ │ │ │ Attester │ │ │ │ Attester │ │ │ │ Attester │ │ │ │ ├───┼────────────┤►│ Vendor A ├─┼────────┼─►│ Vendor B ├─┼─────────────┼──►│ │ │ │ └───────────┘ │ Update PE │ └───────────────┘ │ │ └──────────────┘ │ Update PE │ └───────────┘ │ │ │ with │ │ │ │ with │ │ │ │ AR/RE/PoT │ Operator 1 │ │ Operator 2 │ AR/RE/PoT │ │ └───────────────────┘ └───────────────────┘ └───────────────────┘ └───────────────────┘ Figure 2. NASR Architecture In a more generalized scenario, due to geographic distances, a single operator cannot span across a long distance to deliver an end-to-end service-- multiple operators collaborate to deliver it. The Customer A would send the Path Request to the Operator nearest to him (Operator 1). Operator 1 pass down the Path Request to the collaborating operators, through an intra-ISP API. Operators of different domains choose qualifying devices to altogether orchestrate the path. Relying Party (customer) then sends the Path Evidence inquiry to check and attest to this path. Following the same procedure, the client of other side would return the Path Attestation Result back, through the operators. The Operator 1 would send back a comprehensive answer/report to the Client. Also, the operators may have heterogeneous network devices from different vendors. Since vendors provide Verifier software/hardware and Reference Values, Verifiers can be deployed either outside the operators (Fig 2) or inside of the operators (Fig 3). ┌────────────────────────────────────────────────────────────────┐ │ │ │ ┌────────────┐ ┌────────────┐ │ │ │ Verifier │ │ Verifier │ │ │ │ Owner │ │ Owner │ ... │ │ │ Vendor A │ │ Vendor B │ │ │ └───────┬────┘ └──────┬─────┘ Vendors │ │ │ │ │ └───────────────┼─────────────────────────────┼──────────────────┘ │ Verifier software/hardware │ │ Reference Value │ ┌───────────────────┐ ┌────────┼──────────┐ ┌─────────┼─────────┐ ┌───────────────────┐ Liu, et al. Expires 8 January 2025 [Page 5] Internet-Draft NASR-Architecture July 2024 │ │ │ │ │ │ │ │ │ │ │ │ │ ┌─────▼──────┐ │ │ ┌─────▼──────┐ │ │ │ │ Client A │ │ │ Verifier │ │ │ │ Verifier │ │ │ Client B │ │ │ Path │ │ from │ │ │ │ from │ │ Path │ │ │ ┌──────────────┐ │ Request │ │ Vendor A │ │ │ │ Vendor B │ │ Attestation │ ┌────────────┐ │ │ │ Relying ├─┼──────────┐ │ └──┬─────┬───┘ │ │ └──┬────┬────┘ │ Result (PAR)│ │ Relying │ │ │ │ Party │ │ │ │ │ │ │ │ │ │ │ ┌───────┼───┤ Party │ │ │ └───┬──────────┘◄├────────┐ │ │ │ │ │ Intra │ │ │ │ │ │ └────────────┘ │ │ │ │ │ │ │ RE │ │AR │ ISP │ RE │ │ AR │ │ │ ▲ │ │ │ │ │ └─► ┌───┴─────▼─────┐ │ API │ ┌───┴────▼────┐ │ │ │ │ │ │ │Path │ Report │ │ │ Orchestrator ├─┼────────┼─►│ Orchestrator│◄─┼─────┘ │ │ │ │ │Evidence │ └───┤ └───▲─────┬─────┘ │ │ └───▲────┬────┘ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ RE │ │AR │ │ RE │ │ AR │ │ │ │ │ ┌──▼────────┐ │ │ ┌───┴─────▼─────┐ │ │ ┌───┴────▼─────┐ │ │ ┌───────┴───┐ │ │ │ Attester │ │ │ │ Attester │ │ │ │ Attester │ │ │ │ Attester │ │ │ │ ├───┼────────────┼─┤ Vendor A ├─┼────────┼─►│ Vendor B ├─┼─────────────┼──►│ │ │ │ └───────────┘ │ Update PE │ └───────────────┘ │ │ └──────────────┘ │ Update PE │ └───────────┘ │ │ │ with │ │ │ │ with │ │ │ │ AR/RE/PoT │ Operator 1 │ │ Operator 2 │ AR/RE/PoT │ │ └───────────────────┘ └───────────────────┘ └───────────────────┘ └───────────────────┘ Figure 3. Verifier deployed in operators # Roles {#roles} The existing roles from RATS Architecture document {{RFC9344}} applies. - Attester: The definition in {{RFC9344}} applies. Additionally, it can be performed by either a physical device or a virtual function. The Attester can update Path Evidence with his Attestation Result/Raw Evidence/Proof of Transit. - Produces: (updated) Path Evidence - Relying Party: The definition in {{RFC9344}} applies. Additionally, it creates Path Request to the Orchestrator, and receive Reports from Orchestrator as an auditable result, comparing the actually received network service versus the requested PR attributes. - Produces: Path Request - Consumes: Report In the case where an Attester is deployed in the customer premises, the Relying Party could also start the unfilled Path Evidence inquiry at his side. New role(s) are defined below. - Orchestrator: A role performed by an entity (typically a controller or a special device) that performs two functions: path orchestration and path attestation. The input and output of different functions are different. - Path Orchestration: The Orchestrator receives a Path Request from the Relying Party. After path computation/orchestration, he creates configurations to be distributed to the Attesters/devices. - Consumes: Path Request Liu, et al. Expires 8 January 2025 [Page 6] Internet-Draft NASR-Architecture July 2024 - Produces: Configurations - Path Attestation: The Orchestrator receives a Path Request from the Relying Party, send unfilled Path Evidence (PE) inquiry to Attesters, collects Path Attestation Result (PAR) from the Verifier, and send PAR back to the Relying Party. - Consumes: Path Request, Path Attestation Result - Produces: (unfilled) Path Evidence - Verifier: A role performed by an entity that appraises the validity of filled Path Evidence about a set of Attesters and produces Path Attestation Results to be used by an Orchestrator. - Consumes: (filled) Path Evidence - Produces: Path Attestation Results # Conceptual Messages {#messages} The existing artifacts from RATS Architecture document {{RFC9344}} applies. New conceptual message(s) are defined here. - Path Request: A set of claims, describing the properties of a network path that a Relying Party requested. - Consumed By: Orchestrator - Produced By: Relying Party - Path Attestation Result: The output generated by a Verifier, including information about a set of Attesters, where the Verifier vouches for the validity of the results. - Consumed By: Relying Party - Produced By: Verifier - Path Evidence: The output generated by the Orchestrator and a set of Attesters, to be appraised by a Verifier. Path Evidence may include each Attester's raw Evidence {{RFC9344}}, Attestation Results, Proof-of-Transit, or other proof suggesting correctness of functioning of each Attester. - Consumed By: Verifier - Created By: Orchestrator - Updated By: Attester(s) - Report: An auditable result that compares the actually received network service versus the requested PR attributes. - Created By: Orchestrator - Consumed By: Relying Party # Orchestration The orchestration process collects client's path requests and output configurations. The Orchestrator/Controller then distribute them to the attester/device using NETCONF/YANG or other control plane protocols. In the first case, a new YANG module needs to be defined. Liu, et al. Expires 8 January 2025 [Page 7] Internet-Draft NASR-Architecture July 2024 +------------------------+ | | Path Request |Orchestrator/Controller | -------------->| | +----------+-------------+ | |Path and Security Configuration |(YANG/NETCONF) | +-----v------------+ | Attester/Device | +------------------+ ~~~~ 5. Security Considerations TODO Security 6. IANA Considerations This document has no IANA actions. 7. Informative References [RFC9344] Asaeda, H., Ooka, A., and X. Shao, "CCNinfo: Discovering Content and Network Information in Content-Centric Networks", RFC 9344, DOI 10.17487/RFC9344, February 2023, . [I-D.liu-nasr-requirements-01] Liu, P. C., Iannone, L., Lopez, D., Pastor, A., Chen, M., and L. Su, "NASR Use Case and Requirements", Work in Progress, Internet-Draft, draft-liu-nasr-requirements-01, 3 March 2024, . [I-D.richardson-nasr-terminology-01] Richardson, M. and P. C. Liu, "Terminology and Use cases for Secured Routing Infrastructure", Work in Progress, Internet-Draft, draft-richardson-nasr-terminology-01, 20 May 2024, . [I-D.ietf-rats-ar4si-06] Voit, E., Birkholz, H., Hardjono, T., Fossati, T., and V. Scarlata, "Attestation Results for Secure Interactions", Work in Progress, Internet-Draft, draft-ietf-rats-ar4si- 06, 4 March 2024, . Liu, et al. Expires 8 January 2025 [Page 8] Internet-Draft NASR-Architecture July 2024 [I-D.ietf-rats-corim-04] Birkholz, H., Fossati, T., Deshpande, Y., Smith, N., and W. Pan, "Concise Reference Integrity Manifest", Work in Progress, Internet-Draft, draft-ietf-rats-corim-04, 4 March 2024, . Acknowledgments We sincerely thank contribution from NASR mailing list. Authors' Addresses Chunchi Liu Huawei Email: liuchunchi@huawei.com Meiling Chen China Mobile Email: chenmeiling@chinamobile.com Michael Richardson Sandelman Software Works Email: mcr@sandelman.ca Diego Lopez Telefonica Email: diego.r.lopez@telefonica.com Liu, et al. Expires 8 January 2025 [Page 9]