ISO/IEC 27070:2021

Information technology — Security techniques — Requirements for establishing virtualized roots of trust

This document specifies requirements for establishing virtualized roots of trust.

Technologies de l'information — Techniques de sécurité — Exigences relatives à l'établissement de racines de confiance virtualisées

General Information

• Status: Published
• Publication Date: 05-Dec-2021
• ICS: 35.030 - IT Security
• Technical Committee: ISO/IEC JTC 1/SC 27 - Information security, cybersecurity and privacy protection
• Drafting Committee: ISO/IEC JTC 1/SC 27/WG 4 - Security controls and services
• Current Stage: 6060 - International Standard published
• Start Date: 06-Dec-2021
• Due Date: 26-Mar-2022
• Completion Date: 06-Dec-2021

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 27070
First edition
2021-12
Information technology — Security
techniques — Requirements for
establishing virtualized roots of trust
Technologies de l'information — Techniques de sécurité — Exigences
relatives à l'établissement de racines de confiance virtualisées
Reference number
ISO/IEC 27070:2021(E)
© ISO/IEC 2021

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ISO/IEC 27070:2021(E)
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© ISO/IEC 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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ISO/IEC 27070:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.2
5 Functional view .3
5.1 Overview . 3
5.2 Hardware layer components . 4
5.2.1 General . 4
5.2.2 Functional requirements of key components . 4
5.2.3 Security requirements of key components . 4
5.3 VMM layer components . 5
5.3.1 Functional requirements of key components . 5
5.3.2 Security requirements of key components . 6
5.4 VM layer components . 7
5.5 Cloud OS layer components . 8
5.5.1 General . 8
5.5.2 Functional requirements of key components . 8
5.5.3 Security requirements of key components . 8
6 Activity view . 9
6.1 General . 9
6.2 Transitive trust . 9
6.2.1 General . 9
6.2.2 Transitive trust in host . 10
6.2.3 Transitive trust in VMM . 10
6.2.4 Transitive trust in VM. 10
6.3 Integrity measurement . 10
6.4 Remote attestation . 11
6.5 Data protection .12
6.5.1 General .12
6.5.2 Data binding .12
6.5.3 Data sealing . 13
6.6 vTM migration . 14
Annex A (informative) Relationship between activity and functional views .16
Bibliography .18
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ISO/IEC 27070:2021(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work.
The procedures used to develop this document and those intended for its further maintenance
are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria
needed for the different types of document should be noted. This document was drafted in
accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or
www.iec.ch/members_experts/refdocs).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC
list of patent declarations received (see patents.iec.ch).
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constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence
to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT),
see www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 27, Information security, cybersecurity and privacy protection.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national-committees.
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ISO/IEC 27070:2021(E)
Introduction
Trusted computing is a kind of security technology based on hardware trusted modules, which aims to
ensure that a computer behaves as expected. The trusted computing technology has been developing
fast since its establishment in the 1980s.
The emergence of cloud computing provides a new application scenario for trusted computing
technology. Trust can be established in VMs using a RoT on the physical machine and a virtualized RoT
in the VM and mechanism to bind them together to provide assurance they are on the same machine.
The trusted migration of a VM could use trusted computing to establish trust in the state of the source
and destination physical machines (including their VMM software) and components involved in the
migration process. In the cloud computing environment, a single physical RoT only provides limited
resources and computing efficacy, which is not enough for the large number of VMs on one server.
To address this issue, virtualized RoTs are used. Using virtualization technology to create multiple
virtualized RoTs on a single physical platform, providing a virtualized RoT for each VM, combined with
cryptographic technology to support secure and trusted migration of VMs, thereby building a trusted
cloud computing environment. The establishment procedure of virtualized RoTs consists of multiple
steps, and any security problem in any step diminishes the trustworthiness of virtualized RoTs,
resulting in an inability to establish trust using the virtualized RoTs.
The goal of the document is to provide a unified approach to virtualize RoTs based on hardware trusted
modules.
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INTERNATIONAL STANDARD ISO/IEC 27070:2021(E)
Information technology — Security techniques —
Requirements for establishing virtualized roots of trust
1 Scope
This document specifies requirements for establishing virtualized roots of trust.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
attestation key
AK
particular type of trusted module (3.7) signing key that has a restriction on its use, in order to prevent
forgery
3.2
endorsement key
EK
key that is used in a process for the issuance of attestation key (3.1) credentials and to establish a
platform owner
3.3
integrity measurement
process of calculating the hash value of the measured object using the cryptographic hash algorithm
3.4
root of trust
RoT
component that needs to always behave in the expected manner because its misbehaviour cannot be
detected
Note 1 to entry: The complete set of roots of trust has at least the minimum set of functions to enable a description
of the platform characteristics that affect the trust of the platform.
[SOURCE: ISO/IEC 11889-1, 3.59, modified — The abbreviated term has been added.]
3.5
remote attestation
RA
process of evaluating integrity measurements generated using a root of trust (3.4) for measurement,
storage and reporting to establish trust in a platform remotely
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ISO/IEC 27070:2021(E)
3.6
sensitive information
information is sensitive that the trusted module (3.7) does not allow access to the information without
proper authority
Note 1 to entry: An example of sensitive information in a trusted module is the private of an asymmetric key.
3.7
trusted module
TM
module for trusted computing providing integrity measurement, integrity report, cryptographic
service, random number generation, secure storage functions and a set of platform configuration
registers
Note 1 to entry: There are several implementations of trusted module, such as TPM, TCM, etc.
3.8
virtual machine
VM
virtualized hardware environment in which an operating system can execute, but whose functions are
accomplished by sharing the resources of a real data processing system
3.9
virtual trusted module
vTM
component associated with a single virtual machine (3.8) that provides the functionality described in a
trusted module (3.7)
3.10
virtual platform configuration register
vPCR
one or more platform configuration registers within a virtual trusted module (3.9)
4 Symbols and abbreviated terms
BIOS basic input/output system
CPU central processing unit
CRTM core root of trust for measurement
GPT globally unique identifier partition table
KEK key encryption key
MBR master boot record
OS operating system
PCR platform configuration register
PCA privacy certificate authority
PI platform initialization
ROM read-only memory
SRK storage root key
TPM trusted platform module
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ISO/IEC 27070:2021(E)
TCM trusted cryptography module
TSS trusted software stack
UEFI unified extensible firmware interface
VMM virtual machine monitor
vCRTM virtual core root of trust for measurement
vRTM virtual root of trust for measurement
vRTR virtual root of trust for reporting
vRTS virtual root of trust for storage
vSRK virtual storage root key
WK work key
5 Functional view
5.1 Overview
This clause provides a neutral architectural view of functional components required by trusted
computing activities in the cloud computing environment. It also presents the functional and security
requirements for key components.
Figure 1 shows a framework of the required functional components, where specific types of functions
are grouped into each layer.
Figure 1 — Framework of functional components
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ISO/IEC 27070:2021(E)
5.2 Hardware layer components
5.2.1 General
At the bottom of the architecture, the hardware layer that includes hardware resources and devices is
the base for building a trusted computing platform. This layer provides a RoT for the physical machine
that typically offers trusted platform services for the VMM layer.
NOTE The VMM layer is also known as the hypervisor layer.
This layer also includes the CRTM, the initial set of instructions executed for establishing a new chain of
trust for integrity measurement.
The hardware layer components include but are not limited to:
— power: Powering the computer system for booting and running. The Trusted Module (TM) can
control power such that it can increase security by turning off the power if verification of the boot
fails against a policy;
— TM: A trusted module on a special co-processor or chip with capabilities that include but not limited
to integrity measurement, integrity reporting, generation of signatures for measured integrity
values, key management, secure storage, identity verification, etc.;
The TM shall support a root of trust for measurement, implement a root of trust for reporting and
provide a root of trust for storage. See TM standards for details.
— BIOS/UEFI: A firmware with capabilities of initializing the platform, starting an OS loader and
providing runtime services to the OS;
— CPU: The operating centre of the computing system.
The power, BIOS/UEFI and CPU have no special functional or security features to support virtualized
RoTs. Hence, this document only lists the functional and security requirements for the TM in 5.2.2 and
5.2.3.
5.2.2 Functional requirements of key components
A TM shall provide the following functions.
— Support the integrity measurement, storing, generation of signatures for measured integrity values
and reporting measured values for platform.
— Support key generation for use as signature keys.
— Support cryptographic algorithms, such as hash algorithm, encryption/decryption algorithm, but
are not limit to any specific sets of algorithms.
— Protect integrity measurements in the PCR.
5.2.3 Security requirements of key components
A TM shall meet the following security requirements.
— Ensure the security of a TM itself.
— Ensure the security of confidential information, such as keys.
— Provide the secure storage area to store an SRK to ensure the security of the key information.
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ISO/IEC 27070:2021(E)
5.3 VMM layer components
The VMM layer provides virtualization services to VMs and ensures that VMs can operate independently.
This layer also provides virtualized RoTs for VMs, which includes virtual vRTM, vRTR and vRTS.
The VMM layer components include but are not limited to:
— VMM: It virtualizes the underlying hardware platform to enable multiple VMs to run in isolated
environments and share the hardware resources;
— unified TSS-1: It provides a unified interface for upper layer applications to utilize TM functions
without considering heterogeneous TSS implementations specifically;
— vTM manager: It establishes and maintains the binding list between each vTM instance and VM. It
is responsible for creation, instantiation, deletion, start, stop and migration of the vTM instance
associated with each VM;
— vTM instance: It emulates a hardware TM. Each vTM instance imitates interfaces and functions of
the TM;
— RA client: It retrieves and transmits the integrity evidence of host and VMM layer. It does not leak
the sensitive information during communication with RA server;
— migration engine: It provides capabilities of package, serialization and protection for vTM state data
during transmission. It guarantees that only one vTM instance is active during transmission and the
vTM instance is removed once it has been successfully migrated.
The VMM, unified TSS-1 and RA client have no special functional or security features to support
virtualized RoTs. Hence, this document only lists the functional and security requirements for vTM
manager, vTM instance and migration engine in 5.3.1 and 5.3.2.
5.3.1 Functional requirements of key components
5.3.1.1 vTM manager
A vTM manager shall provide the following functions.
— Create a new vTM instance along with the new VM creation.
— Establish a one-on-one correspondence between a VM and a vTM instance to ensure that each vTM
instance only provides services for a dedicated VM.
— Instantiate a previous (saved) vTM instance when the VM reboot.
— Initialize the vTM instance that is expected to be reset during VM reboot.
— Maintain the non-volatile vTM instance when power on/off or VM reboot.
— Delete the vTM instance once the associated VM has been removed or migrated.
— Protect the vTM instance confidentiality and integrity.
— Bind the vTM instance exclusively with a VM’s lifecycle until the VM is migrated to another platform.
5.3.1.2 vTM instance
A vTM instance shall provide the following functions.
— The vTM instance implementation shall be functionally compatible with the TM.
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ISO/IEC 27070:2021(E)
— The vTM instance implementation shall ensure that only the authorized VM associated with the
vTM instance has access to the vTM instance’s external interfaces.
— The vTM instance shall be de
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