| Internet-Draft | voucher-security-profile | May 2024 |
| Mohammed, et al. | Expires 27 November 2024 | [Page] |
This document describes an extension of the RFC8366 Voucher Artifact in order to support security profiles. This allows the owner to change and customize the security posture of the device dynamically and securely. This lets the owner to selectively enable or disable each of the underlying security parameters that make up the security posture of the device.¶
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The [RFC8366] voucher artifact provides a proof from a manufacturer's authorizing signing authority (MASA) of the intended owner of a device. This is used by an onboarding Pledge device in BRSKI ([RFC8995], [I-D.ietf-anima-constrained-voucher]), and SZTP ([RFC8572]).¶
The security profile for a device can be defined as a sum collection of the settings of the different underlying security parameters that determine the overall security posture of a device. There are many reasons for the need and they include:¶
There are various underlying security parameters that are possible. These can be divided into Common, OEM specific and Reserved (for future use).¶
Some examples of common and standard ones (others may be added in future revisions of the draft) are below.¶
Extensions to standards-based RFC8366 Voucher Artifact handles different and varying security postures for the owner that would have otherwise needed complex manufacturing end-customer security profile handling and tracking.¶
In the context of standalone EST [RFC 7030] or BRSKI-EST [RFC 8995] protocol, the owner's security policies can be sent as a policy update during LDevID renewal via BRSKI-EST link with new actions and the policy data can be an update signed by domain CA. However, to keep it nice and simple and in the context of the nature of the policies addressed here (i.e., may need security gates, under manufacturer's purview, to be opened in the device and licensing aspects to be addressed with the vendor or manufacturer), it is thought that it could be better served via voucher extensions, that includes MASA in the loop.¶
This allows ease of use and management for owners by providing secure ways for dynamic changes and alteration of security postures for the owner, at scale.¶
The OEM specific aspects are kept private while the Reserved aspects are reserved for future use.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
The following tree diagram shows the extensions to the [RFC8366] voucher.¶
There are a few new fields:¶
A global enable flag to the pledge that security profiles for this pledge is enabled(true) or not (false). With default, this flag is false, which is consistent with the voucher artifact in RFC8366.¶
Bitmask value of all the underlying security parameters¶
module: ietf-voucher-security-profile
grouping voucher-security-profile-grouping:
+-- voucher
+-- created-on yang:date-and-time
+-- expires-on? yang:date-and-time
+-- serial-number string
+-- idevid-issuer? binary
+-- pinned-domain-cert? binary
+-- domain-cert-revocation-checks? boolean
+-- nonce? binary
+-- last-renewal-date? yang:date-and-time
+-- security-profile-enable-flag? boolean
+-- (security-parameters)?
¶
This module uses the grouping that was created in [RFC8366] to extend the definition.¶
<CODE BEGINS> file "[email protected]" module ietf-voucher-security-profile { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-voucher-security-profile"; prefix "security-profile"; import ietf-restconf { prefix rc; description "This import statement is only present to access the yang-data extension defined in RFC 8040."; reference "RFC 8040: RESTCONF Protocol"; } import ietf-voucher { prefix "iv"; } organization "IETF ANIMA Working Group"; contact "WG Web: <http://tools.ietf.org/wg/anima/> WG List: <mailto:[email protected]> Author: Srihari Raghavan <mailto:[email protected]>"; description "This module extends the RFC8366 voucher format to provide a mechanism by which the authority can configure the security posture of the device. The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and 'OPTIONAL' in the module text are to be interpreted as described in BCP 14 RFC 2119, and RFC8174."; revision "2024-05-26" { description "Updates to security profile aspects"; reference "RFC XXXX: Voucher extensions for security profile"; } revision "2023-11-27" { description "Updates to security profile aspects"; reference "RFC XXXX: Voucher extensions for security profile"; } revision "2023-05-30" { description "Initial version"; reference "RFC XXXX: Voucher extensions for security profile"; } feature security-profile-ietf { description "This feature indicates that the IETF version of the security profile feature is supported"; reference "RFC XXXX: Voucher extensions for security profile"; } feature security-profile-oem { description "This feature indicates that the oem version of the security profile feature is supported. The OEM list is expected to be based on https://www.iana.org/assignments/enterprise-numbers/ (PENs)."; reference "RFC XXXX: Voucher extensions for security profile"; } rc:yang-data voucher-security-profile-artifact { // YANG data template for a voucher. uses voucher-security-profile-grouping; } typedef bitmask64 { type uint64; description "The bitmask64 type represents a non-negative integer that represents a bit mask type field with each bit set (or unset) representing a different intent along with a range of bits/values representing a group. Using an appropriate mask, the individual bits can be set/reset. In addition, a range of bits can also be manipulated using an appropriate mask. The 'type bits' and 'position' yang based bit fields do not lend itself easily to range based comparisons and hence the need for a customized type definition. The bitmask64 type can be used for configuration schema nodes. A default statement can be used in combination with the type bitmask64."; reference "RFC 2578: Structure of Management Information Version 2 (SMIv2)"; } // Grouping for security parameters forming the security profile // // These are separated into two-groups: standardized and OEM. // // The security-parameters-standard are subject to standards definition // for inter-operability while the OEM range is expected to be // implementation dependent. // // // The specific bits are expected to be defined // following discussions with WG members and some examples // could be FIPS mode handling, SELinux handling, // Linux IMA handling etc., which could decide the // overall security posture of a device."; // // grouping security-parameters-group { leaf security-params-value { type bitmask64; description "Bit map for the different underlying security parameters. This is only valid if security-profile-enable-flag is true. Range: - 0x1, 0x2, 0x4..0x8000..0x10000.. "; } leaf security-params-mask { type bitmask64; description "This represents the mask for the value above. If this mask is on for a bit, the corresponding value of the bit will be treated accordingly. If the mask is off, the value of the bit could be treated as a don't care or default value"; } description "The underlying security profile parameters."; } grouping security-parameters { container security-parameters-standard { if-feature security-profile-ietf; description "Security profiles based on IETF version."; leaf enabled { type boolean; default false; description "When true, IETF version of security profiles MUST be processed."; } uses security-parameters-group; } container security-parameters-oem { if-feature security-profile-oem; description "Security profiles based on OEM version."; leaf enabled { type boolean; default false; description "When true, OEM version of security profiles MUST be processed."; } uses security-parameters-group; } description "Security profile parameters."; } grouping voucher-security-profile-grouping { description "Grouping to allow reuse/extensions in future work."; uses iv:voucher-artifact-grouping { augment "voucher" { description "Base the security profile voucher upon the regular voucher"; leaf security-profile-enable-flag { type boolean; description "A global enable flag to the pledge that security profiles for this pledge is enabled(true) or not (false). With default, this flag is false, which is consistent with the voucher artifact in RFC8366. "; } uses security-parameters; } } } } <CODE ENDS>¶
The use of a security profile voucher requires changes to how the pledge evaluates the voucher that is returned to by the Registrar.¶
If the pledge supports this extension, it looks for security-profile-enable-flag and if set, the security-profile-selector MUST be processed.¶
The Registrar (Join Registrar or Co-ordinator) is the representative of the domain that is configured to decide whether a new device is allowed to join a domain. The Manufacturer Authorized Signing Authority (MASA) signs vouchers and if the extensions are supported, it MUST process a security profile selector request from owner that identifies what underlying security parameters need to be enabled in the security-profile-selector to be sent down to the pledge as part of these extensions. As outlined in RFC 8995, the domain Registrar authenticates the pledge, makes authorization decisions, and distributes vouchers obtained from the MASA service and this is not expected to change.¶
The security profile selector request from owner could take the form of a programmatic API based parameterized interaction with the MASA service.¶
This document requires the following IANA actions:¶
This document registers a URI in the "IETF XML Registry" [RFC3688]. IANA is asked to register the following:¶
URI: urn:ietf:params:xml:ns:yang:ietf-voucher-security-profile
Registrant Contact: The ANIMA WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
¶
This document registers a YANG module in the "YANG Module Names" registry [RFC6020]. IANA is asked to register the following:¶
name: ietf-voucher-security-profile
namespace: urn:ietf:params:xml:ns:yang:ietf-voucher-security-profile
prefix: NONE
reference: THIS DOCUMENT
¶
Implementation of the proposal is under active development.¶
The authors would like to thank Michael Richardson and Esko Dijk for their valuable comments and guidance.¶
RFC Editor, please remove this section. This section lists references in the YANG. [RFC8174], [RFC8040].¶