TEEP Working Group P. Yang
Internet-Draft M. Chen
Intended status: Informational L. Su
Expires: 13 April 2023 China Mobile
T. Pang
Huawei Technology Co.,Ltd.
10 October 2022
TEEP Usecase for Confidential Computing in Network
draft-ietf-teep-usecase-for-cc-in-network-01
Abstract
Confidential computing is the protection of data in use by performing
computation in a hardware-based Trusted Execution Environment.
Confidential computing could provide integrity and confidentiality
for users who want to run applications and process data in that
environment. When confidential computing is used in scenarios which
need network to provision users' data and applications in the TEE
environment, TEEP architecture[I-D.ietf-teep-architecture] and
protocol[I-D.ietf-teep-protocol] could be used. This document
focuses on using TEEP to provision network users' data and
applications in confidential computing. This document is a use case
and extension of TEEP and could provide guidance for cloud computing,
MEC[MEC] and other scenarios to use confidential computing in
network.
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
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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 13 April 2023.
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Copyright Notice
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document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Terms . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
3. Notional Architecture of using confidential computing in
network . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Usecases . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. UA, TA and PD are bundled as a package . . . . . . . . . 5
4.2. PD is a separate package, TA and UA are separate or
integrated . . . . . . . . . . . . . . . . . . . . . . . 6
4.3. TA and PD are bundled as a package, and UA is a separate
package . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.4. TA and PD as a package, no UA . . . . . . . . . . . . . . 8
4.5. TA and PD are separate packages, no UA . . . . . . . . . 9
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.1. Normative Reference . . . . . . . . . . . . . . . . . . . 10
8.2. Informative Reference . . . . . . . . . . . . . . . . . . 11
Appendix A. Submodules in TEEP Agent . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
The Confidential Computing Consortium defined the concept of
confidential computing as the protection of data in use by performing
computation in a hardware-based Trusted Execution
Environment"[CCC-White-Paper]. In detail, computing unit with
confidential computing feature could generate an isolated hardware-
protected area, in which data and applications will be protected from
illegal access or tampering. When using network to provision
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confidential computing environment, users need to attest and deploy
their data and applications in the TEE environment inside
confidential computing device by network. This network could be a
cloud, MEC or other network that provide confidential computing
resource to users.
The TEEP WG defined the standardization of an architecture and
protocol for managing the lifecycle of trusted applications running
inside a TEE. In confidential computing, the TEE can also be
provisioned and managed by TEEP architectue and protocol.
This document illustrates how a network user uses the TEEP protocol
to provision its private data and applications in confidential
computing device. The intended audiences for this use case are
network users and operators who are interested in using confidential
computing in network.
2. Terminology
2.1. Terms
* Network Management/Orchestration Center(Network M/OC): MO/C exists
in the management and orchestration layer of network. Network
user uses the M/OC to request for computing resource. The TAM is
inside the M/OC to provide management function to TEEP agent via
TEEP broker.
* Network user: Network user possesses personalization data and
applications that need to be deployed on confidential computing
device. For example in MEC, the autonomous vehicles could deploy
private applications and data on confidential computing device to
calculate on-vehicle and destination road information without
knowing by MEC platform.
* Confidential Computing Device: Confidential Computing Device is
connected by the network and can provide confidential computing
service to network user.
* Package: Package is a unit that is signed or encrypted by Data
Owner and could be deployed on TEE/REE or treated as application
data. TA (Trusted Application) in confidential computing could be
an application, or packaged with other components like library,
TEE shim or even Guest OS. The specific package of confidential
computing could refers to the white paper of common
terminology[CCC_Common_Terminology] by CCC.
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2.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
3. Notional Architecture of using confidential computing in network
Figure 1 is the architecture of confidential computing in network.
Two new components Network User and Network M/OC are introduced in
this document. The connection between network user and M/OC depends
on the implementation of specific network. The connection between
network user and UA (Untrusted Application) or TA depends on the
implementation of application. The connection between TAM, TEEP
Broker and TEEP Agent refers to the TEEP protocol. Interactions of
all components in this scenario are described in the Usecase section.
+--------------------------------------+
| Confidential Computing Device |
| +--------+ | +------------+
| +-------------+ | | | |Network M/OC|
| | TEE | | TEEP | | | +-------+ |
| | +--------+ | +---> Broker <-----------> | |
| | | TEEP | | | | | | | | TAM | |
| | | Agent |<----+ | | | | | | |
| | +--------+ | | <--+ | | +---^---+ |
| | | +--------+ | | +-----|------+
| | +--------+ | | | |
| | | TA | | +-------+ | | |
| | | |<--------> |<--+ | |
| | +--------+ | | UA | | +-----V------+
| +-------------+ | |<--------->Network User|
| +-------+ | | (Package) |
+--------------------------------------+ +------------+
Figure 1: notional architecture of confidential computing in network
4. Usecases
The basic process of how a network user utilizes confidential
computing is shown below. In confidential computing, the bundle of
an UA, TA, and PD refers to case 1,2,3,4 of TEEP architecture section
4.4. Case 5 and 6 are new cases that possible in implementation. At
present, the main instances types exist in industry of confidential
computing are confidential process,confidential container and
confidential VM.
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4.1. UA, TA and PD are bundled as a package
This use case refers to the case 1 of TEEP architecture. If the
network user provides this package, the process of TEEP is as follow.
1. Network user requests for confidential computing resource to the
network M/OC.
2. M/OC orchestrates confidential computing device to undertake the
request.
3. TAM requests remote attestation to the TEEP Agent, TEEP Agent
then sends the evidence to TAM. The TAM works as Verifier in
RATs architecture[I-D.ietf-rats-architecture]
4. After verification, Network User works as Relying Party receives
the attestation result. If positive, Network User transfers the
package to TEEP Agent.
5. Network user establishes secure channel with TEEP agent, and
transfers this package to TEEP Agent.
6. TEEP Agent deploys TA and personalization data, then deploy UA in
REE via TEEP Broker
As for informing network users to develop their applications and
data, the mapping of UA, TA and implementations are shown in figure
2. This document gathers the main hardware architectures that
support confidential computing, which include TrustZone[TrustZone],
SGX[SGX], SEV-SNP[SEV-SNP], CCA[CCA] and TDX[TDX]. The brace means
the operation steps to deploy packages. The arrow means deploy
package to a destination.
The brace means the operation steps to deploy packages. The arrow
means deploy package to a destination.
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+-------------+--------------------------------------------------+
|Package Mode | Case 1 (UA, TA, PD) |
+-------------+----------------+----------------+----------------+
| Instance | Process in | Container in | |
| Type | Physical or | Physical or | VM |
| | Virtual Machine| Virtual Machine| |
+-------------+----------------+----------------+----------------+
| Hardware | | TrustZone, | |
| Architecture| TrustZone | SEV-SNP, CCA, | SEV-SNP,CCA,TDX|
| | | TDX | |
+-------------+----------------+----------------+----------------+
| |{att TEEP Agent,|{att TEEP Agent,|{att TEEP Agent,|
| Load | TA->TEE, | TA->Trsuted | TA->Trsuted VM |
| Sequence | PD->TA, | Container, | PD->TA, |
| | UA->REE} | PD->TA, | UA->Untrusted |
| | | UA->REE} | VM} |
+-------------+----------------+----------------+----------------+
Figure 2: TEEP Implementation of Case 1
4.2. PD is a separate package, TA and UA are separate or integrated
This usecase refers to the case 2 and case 3 of TEEP architecture.
The PD is a separate package, the UA and TA could be separated or
integrated as a package. If the network user provides packages like
this, the process of TEEP is as follow.
1. Network user requests for confidential computing resource to the
network M/OC.
2. M/OC orchestrates confidential computing device to undertake the
request.
3. Network user transfers UA and TA to confidential computing device
via TAM. TAM then deploys these two applications in REE and TEE
respectively. (In SGX, UA must be deployed first, then let the
UA to load TA in SGX.)
4. TAM requests remote attestation to the TEEP Agent, TEEP Agent
then sends the evidence to TAM. The TAM works as Verifier in
RATs architecture.
5. After verification,Network User works as Relying Party receives
the attestation result. If positive, Network User establishes
secure channel with TA, and deploys personalization data to the
TA.
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The mapping of UA, TA and implementations are shown in figure 3.
+-------------+--------------------------------------------------+
|Package Mode | Case 2 (UA, TA) (PD), Case 3 (UA) (TA) (PD) |
+-------------+----------------+----------------+----------------+
| Instance | Process in | Container in | |
| Type | Physical or | Physical or | VM |
| | Virtual Machine| Virtual Machine| |
+-------------+----------------+----------------+----------------+
| Hardware | TrustZone, | TrustZone, SGX,| |
| Architecture| SGX | SEV-SNP, CCA, | SEV,CCA,TDX |
| | | TDX | |
+-------------+----------------+----------------+----------------+
| | {TA->TEE, | {UA->REE, |{UA->untrusted |
| | att TEEP Agent,| TA->trusted | VM, |
| Load | PD->TA, | Container, | TA->trusted VM,|
| Sequence | UA->REE} | att TEEP Agent,| att TEEP Agent,|
| | | PD->TA} | PD->TA} |
+-------------+----------------+----------------+----------------+
Figure 3: TEEP Implementation of Case 2/3
4.3. TA and PD are bundled as a package, and UA is a separate package
In this case, the process of TEEP is as follow.
1. Network user requests for confidential computing resource to the
network M/OC.
2. TAM in M/OC orchestrates confidential computing device to
undertake the request.
3. Network user deploys UA in REE.
4. TAM requests remote attestation to the TEEP Agent, TEEP Agent
then sends the evidence to TAM. The TAM works as Verifier in
RATs architecture
5. After verification,Network User works as Relying Party receives
the attestation result. If positive, the Network User creates
secure channel with TEEP Agent and transfers the TA and PD
package to TEEP Agent.
6. TEEP Agent decrypts this package and deploys TA and PD.
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+-------------+--------------------------------------------------+
|Package Mode | Case 4 (TA, PD) (UA) |
+-------------+----------------+----------------+----------------+
| Instance | Process in | Container in | |
| Type | Physical or | Physical or | VM |
| | Virtual Machine| Virtual Machine| |
+-------------+----------------+----------------+----------------+
| Hardware | TrustZone, | TrustZone, SGX,| |
| Architecture| SGX | SEV-SNP, CCA, | SEV,CCA,TDX |
| | | TDX | |
+-------------+----------------+----------------+----------------+
| | {UA->REE, | {UA->REE, | {UA->untrusted |
| Load | att TEEP Agent,| att TEEP Agent,| VM, |
| Sequence | TA&PD->TEE} | TA&PD->trusted | att TEEP Agent,|
| | | Container} | TA->trusted VM}|
+-------------+----------------+----------------+----------------+
Figure 4: TEEP Implementation of Case 4
4.4. TA and PD as a package, no UA
In this case, network user provides TA and PD as a package with no UA
attached. The process of TEEP in this case is as follow.
1. Network user requests for confidential computing resource to the
network M/OC.
2. TAM in M/OC orchestrates confidential computing device to
undertake the request.
3. TAM requests remote attestation to the TEEP Agent, TEEP Agent
then sends the evidence to TAM. The TAM works as Verifier in
RATs architecture.
4. After verification,Network User works as Relying Party receives
the attestation result. If positive, the Network User
establishes secure channel with TEEP Agent and transfers TA and
PD to TEEP Agent.
5. TEEP Agent decrypts this package and deploys TA and PD.
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+-------------+--------------------------------------------------+
|Package Mode | Case 5 (TA, PD) |
+-------------+----------------+----------------+----------------+
| Instance | Process in | Container in | |
| Type | Physical or | Physical or | VM |
| | Virtual Machine| Virtual Machine| |
+-------------+----------------+----------------+----------------+
| Hardware | TrustZone, | TrustZone, SGX,| SEV,CCA,TDX |
| Architecture| SGX | SEV, CCA, TDX | |
+-------------+----------------+----------------+----------------+
| Load |{att TEEP Agent,|{att TEEP Agent,|{att TEEP Agent,|
| Sequence | TA&PD->TEE} | TA&PD->trusted | TA->trusted VM}|
| | | Container} | |
+-------------+----------------+----------------+----------------+
Figure 5: TEEP Implementation of Case 5
4.5. TA and PD are separate packages, no UA
In this case, network user provides TA and PD as separate packages
with no UA attached. The process of TEEP in this case is as follow.
1. Network user requests for confidential computing resource to the
network M/OC.
2. TAM in M/OC orchestrates confidential computing device to
undertake the request.
3. Network User transfers TA to TAM, then TAM transfers TA to TEEP
Agent.
4. TAM requests remote attestation to the TEEP Agent, TEEP Agent
then sends the evidence to TAM. The TAM works as Verifier in
RATs architecture
5. After verification,Network User works as Relying Party receives
the attestation result. If positive, the Network User
establishes secure channel with TA and transfers PD to it.
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+-------------+--------------------------------------------------+
|Package Mode | Case 6 (TA), (PD) |
+-------------+----------------+----------------+----------------+
| Instance | Process in | Container in | |
| Type | Physical or | Physical or | VM |
| | Virtual Machine| Virtual Machine| |
+-------------+----------------+----------------+----------------+
| Hardware | TrustZone, | TrustZone, SGX,| SEV,CCA,TDX |
| Architecture| SGX | SEV, CCA, TDX | |
+-------------+----------------+----------------+----------------+
| Load | {TA->TEE, | {TA->trusted |{TA->trusted VM,|
| Sequence | att TEEP Agent,| Container, | att TEEP Agent,|
| | PD->TA} | att TEEP Agent,| PD->TA} |
| | | PD->TA} | |
+-------------+----------------+----------------+----------------+
Figure 6: TEEP Implementation of Case 6
5. IANA Considerations
This document does not require actions by IANA.
6. Security Considerations
Besides the security considerations in TEEP architecture, there is no
more security and privacy issues in this document.
7. Acknowledgements
TBD
8. References
8.1. Normative Reference
[I-D.ietf-rats-architecture]
Birkholz, H., Thaler, D., Richardson, M., Smith, N., and
W. Pan, "Remote Attestation Procedures Architecture", Work
in Progress, Internet-Draft, draft-ietf-rats-architecture-
22, 28 September 2022, <https://www.ietf.org/archive/id/
draft-ietf-rats-architecture-22.txt>.
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[I-D.ietf-teep-architecture]
Pei, M., Tschofenig, H., Thaler, D., and D. Wheeler,
"Trusted Execution Environment Provisioning (TEEP)
Architecture", Work in Progress, Internet-Draft, draft-
ietf-teep-architecture-18, 11 July 2022,
<https://www.ietf.org/archive/id/draft-ietf-teep-
architecture-18.txt>.
[I-D.ietf-teep-protocol]
Tschofenig, H., Pei, M., Wheeler, D., Thaler, D., and A.
Tsukamoto, "Trusted Execution Environment Provisioning
(TEEP) Protocol", Work in Progress, Internet-Draft, draft-
ietf-teep-protocol-10, 28 July 2022,
<https://www.ietf.org/archive/id/draft-ietf-teep-protocol-
10.txt>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
8.2. Informative Reference
[CCA] ARM, "Arm Confidential Computing Architecture", March
2022, <https://www.arm.com/architecture/security-features/
arm-confidential-compute-architecture>.
[CCC-White-Paper]
Confidential Computing Consortium, "Confidential
Computing: Hardware-Based Trusted Execution for
Applications and Data", January 2021,
<https://confidentialcomputing.io/white-papers-reports/>.
[CCC_Common_Terminology]
Confidential Computing Consortium, "Common Terminology for
Confidential Computing", October 2022,
<https://github.com/confidentialcomputing/governance/blob/
main/terminology/commonterminology.md>.
[MEC] ETSI, "Multi-access Edge Computing (MEC);Framework and
Reference Architecture", March 2022,
<https://www.etsi.org/deliver/etsi_gs/
MEC/001_099/003/03.01.01_60/gs_MEC003v030101p.pdf>.
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[SEV-SNP] Advanced Micro Devices, "AMD SEV-SNP: Strengthening VM-
isolation-with-integrity-protection-and-more", January
2020, <https://www.amd.com/system/files/TechDocs/SEV-SNP-
strengthening-vm-isolation-with-integrity-protection-and-
more.pdf>.
[SGX] Intel, "Overview of Intel Software Guard Extension", June
2016,
<https://www.intel.com/content/www/us/en/developer/tools/
software-guard-extensions/overview.html>.
[TDX] Intel, "Intel Trust Domain Extensions", August 2021,
<https://www.intel.com/content/www/us/en/developer/
articles/technical/intel-trust-domain-extensions.html>.
[TrustZone]
HUAWEI Technologies, "Kunpeng BoostKit for Confidential
Computing TrustZone Kit", January 2022,
<https://www.hikunpeng.com/document/detail/en/
kunpengcctrustzone/overview/kunpengcctrustzone.html>.
Appendix A. Submodules in TEEP Agent
The original design of TEEP only includes TEEP Agent and TA inside
TEE. While in confidential computing implementation, other
submodules may also be involved in the TEE. In TEEP, these
submodules could be covered by TEEP Agent.
In SGX based confidential computing, submodule could provide
convenient environment or API in which TA does not have to modify its
source code to fit into SGX instructions. Submodules like Gramine
and Occlum .etc are examples that could be included in TEEP agent.
If there is no submodule in TEEP agent, the TA and UA need to be
customized applications which fit into the SGX architecture.
In SEV and other architectures that support whole guest VM as a TEE,
TEEP agent doesn't have to use extra submodule to work as a
middleware or API. However with some submodules like Enarx which
works as a runtime JIT compiler, TA could be deployed in a hardware
independent way. In this scenario, TA could be deployed in different
hardware architecture without re-compiling.
Authors' Addresses
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Penglin Yang
China Mobile
32 Xuanwumen West Street, Xicheng District
Beijing
100053
China
Email: yangpenglin@chinamobile.com
Meiling Chen
China Mobile
32 Xuanwumen West Street, Xicheng District
Beijing
100053
China
Email: chenmeiling@chinamobile.com
Li Su
China Mobile
32 Xuanwumen West Street, Xicheng District
Beijing
100053
China
Email: suli@chinamobile.com
Ting Pang
Huawei Technology Co.,Ltd.
127 Jinye Road, Yanta District
Xi'an
710077
China
Email: pangting@huawei.com
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