A YANG Data Model for Challenge-Response-based Remote Attestation Procedures using TPMs
draft-ietf-rats-yang-tpm-charra-00
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|---|---|---|---|
| Authors | Henk Birkholz , Michael Eckel , Shwetha Bhandari , Bill Sulzen , Eric Voit , Liang Xia , Tom Laffey , Guy Fedorkow | ||
| Last updated | 2020-01-07 | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
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draft-ietf-rats-yang-tpm-charra-00
RATS Working Group H. Birkholz
Internet-Draft M. Eckel
Intended status: Standards Track Fraunhofer SIT
Expires: July 10, 2020 S. Bhandari
B. Sulzen
E. Voit
Cisco
L. Xia
Huawei
T. Laffey
HPE
G. Fedorkow
Juniper
January 07, 2020
A YANG Data Model for Challenge-Response-based Remote Attestation
Procedures using TPMs
draft-ietf-rats-yang-tpm-charra-00
Abstract
This document defines a YANG RPC and a minimal datastore tree
required to retrieve attestation evidence about integrity
measurements from a composite device with one or more roots of trust
for reporting. Complementary measurement logs are also provided by
the YANG RPC originating from one or more roots of trust of
measurement. The module defined requires at least one TPM 1.2 or TPM
2.0 and corresponding Trusted Software Stack included in the device
components of the composite device the YANG server is running on.
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 July 10, 2020.
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Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
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 Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3
2. The YANG Module for Basic Remote Attestation Procedures . . . 3
2.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 3
2.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 7
3. IANA considerations . . . . . . . . . . . . . . . . . . . . . 30
4. Security Considerations . . . . . . . . . . . . . . . . . . . 30
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 30
6. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 30
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 30
7.1. Normative References . . . . . . . . . . . . . . . . . . 30
7.2. Informative References . . . . . . . . . . . . . . . . . 31
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
1. Introduction
This document is based on the terminology defined in the
[I-D.ietf-rats-architecture] and uses the interaction model and
information elements defined in the
[I-D.birkholz-rats-reference-interaction-model] document. The
currently supported hardware security modules (HWM) - sometimes also
referred to as an embedded secure element (eSE) - is the Trusted
Platform Module (TPM) version 1.2 and 2.0 specified by the Trusted
Computing Group (TCG). One ore more TPMs embedded in the components
of a composite device - sometimes also referred to as an aggregate
device - are required in order to use the YANG module defined in this
document. A TPM is used as a root of trust for reporting (RTR) in
order to retrieve attestation evidence from a composite device (quote
primitive operation). Additionally, it is used as a root of trust
for storage (RTS) in order to retain shielded secrets and store
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system measurements using a folding hash function (extent primitive
operation).
1.1. Requirements notation
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.
2. The YANG Module for Basic Remote Attestation Procedures
One or more TPM 2.0 MUST be embedded in the composite device that is
providing attestation evidence via the YANG module defined in this
document. The ietf-basic-remote-attestation YANG module enables a
composite device to take on the role of Claimant and Attester in
accordance with the Remote Attestation Procedures (RATS) architecture
[I-D.ietf-rats-architecture] and the corresponding challenge-response
interaction model defined in the
[I-D.birkholz-rats-reference-interaction-model] document. A fresh
nonce with an appropriate amount of entropy MUST be supplied by the
YANG client in order to enable a proof-of-freshness with respect to
the attestation evidence provided by the attester running the YANG
datastore. The functions of this YANG module are restricted to 0-1
TPM 2.0 per hardware component.
2.1. Tree Diagram
module: ietf-tpm-remote-attestation
+--ro rats-support-structures
+--ro supported-algos* uint16
+--ro tpms* [tpm_name]
| +--ro tpm_name string
| +--ro tpm-physical-index? int32 {ietfhw:entity-mib}?
| +--ro certificates* []
| +--ro certificate
| +--ro certificate-name? string
| +--ro certificate-type? enumeration
| +--ro certificate-value? ietfct:end-entity-cert-cms
+--ro compute-nodes* [node-name]
+--ro node-name string
+--ro node-physical-index? int32 {ietfhw:entity-mib}?
rpcs:
+---x tpm12-challenge-response-attestation
| +---w input
| | +---w tpm1-attestation-challenge
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| | +---w pcr-indices* uint8
| | +---w nonce-value binary
| | +---w TPM_SIG_SCHEME-value uint8
| | +---w (key-identifier)?
| | | +--:(public-key)
| | | | +---w pub-key-id? binary
| | | +--:(TSS_UUID)
| | | +---w TSS_UUID-value
| | | +---w ulTimeLow? uint32
| | | +---w usTimeMid? uint16
| | | +---w usTimeHigh? uint16
| | | +---w bClockSeqHigh? uint8
| | | +---w bClockSeqLow? uint8
| | | +---w rgbNode* uint8
| | +---w add-version? boolean
| | +---w tpm_name? string
| | +---w tpm-physical-index? int32 {ietfhw:entity-mib}?
| +--ro output
| +--ro tpm12-attestation-response* [tpm_name]
| +--ro tpm_name string
| +--ro tpm-physical-index? int32 {ietfhw:entity-mib}?
| +--ro up-time? uint32
| +--ro node-name? string
| +--ro node-physical-index? int32 {ietfhw:entity-mib}?
| +--ro fixed? binary
| +--ro external-data? binary
| +--ro signature-size? uint32
| +--ro signature? binary
| +--ro (tpm12-quote)
| +--:(tpm12-quote1)
| | +--ro version* []
| | | +--ro major? uint8
| | | +--ro minor? uint8
| | | +--ro revMajor? uint8
| | | +--ro revMinor? uint8
| | +--ro digest-value? binary
| | +--ro TPM_PCR_COMPOSITE* []
| | +--ro pcr-indices* uint8
| | +--ro value-size? uint32
| | +--ro tpm12-pcr-value* binary
| +--:(tpm12-quote2)
| +--ro tag? uint8
| +--ro pcr-indices* uint8
| +--ro locality-at-release? uint8
| +--ro digest-at-release? binary
+---x tpm20-challenge-response-attestation
| +---w input
| | +---w tpm20-attestation-challenge
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| | | +---w pcr-list* []
| | | | +---w pcr
| | | | +---w pcr-indices* uint8
| | | | +---w (algo-registry-type)
| | | | +--:(tcg)
| | | | | +---w tcg-hash-algo-id? uint16
| | | | +--:(ietf)
| | | | +---w ietf-ni-hash-algo-id? uint8
| | | +---w nonce-value binary
| | | +---w (signature-identifier-type)
| | | | +--:(TPM_ALG_ID)
| | | | | +---w TPM_ALG_ID-value? uint16
| | | | +--:(COSE_Algorithm)
| | | | +---w COSE_Algorithm-value? int32
| | | +---w (key-identifier)?
| | | +--:(public-key)
| | | | +---w pub-key-id? binary
| | | +--:(uuid)
| | | +---w uuid-value? binary
| | +---w tpms* [tpm_name]
| | +---w tpm_name string
| | +---w tpm-physical-index? int32 {ietfhw:entity-mib}?
| +--ro output
| +--ro tpm20-attestation-response* [tpm_name]
| +--ro tpm_name string
| +--ro tpm-physical-index? int32 {ietfhw:entity-mib}?
| +--ro up-time? uint32
| +--ro node-name? string
| +--ro node-physical-index? int32 {ietfhw:entity-mib}?
| +--ro tpms-attest
| | +--ro pcrdigest? binary
| | +--ro tpms-attest-result? binary
| | +--ro tpms-attest-result-length? uint32
| +--ro tpmt-signature? binary
+---x basic-trust-establishment
| +---w input
| | +---w nonce-value binary
| | +---w (signature-identifier-type)
| | | +--:(TPM_ALG_ID)
| | | | +---w TPM_ALG_ID-value? uint16
| | | +--:(COSE_Algorithm)
| | | +---w COSE_Algorithm-value? int32
| | +---w tpm_name? string
| | +---w tpm-physical-index? int32 {ietfhw:entity-mib}?
| | +---w certificate-name? string
| +--ro output
| +--ro attestation-certificates* [tpm_name]
| +--ro tpm_name string
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| +--ro tpm-physical-index? int32 {ietfhw:entity-mib}?
| +--ro up-time? uint32
| +--ro node-name? string
| +--ro node-physical-index? int32 {ietfhw:entity-mib}?
| +--ro certificate-name? string
| +--ro attestation-certificate? ietfct:end-entity-cert-cms
| +--ro (key-identifier)?
| +--:(public-key)
| | +--ro pub-key-id? binary
| +--:(uuid)
| +--ro uuid-value? binary
+---x log-retrieval
+---w input
| +---w log-selector* [node-name]
| | +---w node-name string
| | +---w node-physical-index? int32 {ietfhw:entity-mib}?
| | +---w (index-type)?
| | +--:(last-entry)
| | | +---w last-entry-value? binary
| | +--:(index)
| | | +---w index-number? uint64
| | +--:(timestamp)
| | +---w timestamp? yang:date-and-time
| +---w log-type identityref
| +---w pcr-list* []
| | +---w pcr
| | +---w pcr-indices* uint8
| | +---w (algo-registry-type)
| | +--:(tcg)
| | | +---w tcg-hash-algo-id? uint16
| | +--:(ietf)
| | +---w ietf-ni-hash-algo-id? uint8
| +---w log-entry-quantity? uint16
+--ro output
+--ro system-event-logs
+--ro node-data* [node-name tpm_name]
+--ro node-name string
+--ro node-physical-index? int32 {ietfhw:entity-mib}?
+--ro up-time? uint32
+--ro tpm_name string
+--ro tpm-physical-index? int32 {ietfhw:entity-mib}?
+--ro log-result
+--ro (log-type)
+--:(bios)
| +--ro bios-event-logs
| +--ro bios-event-entry* [event-number]
| +--ro event-number uint32
| +--ro event-type? uint32
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| +--ro pcr-index? uint16
| +--ro digest-list* []
| | +--ro (algo-registry-type)
| | | +--:(tcg)
| | | | +--ro tcg-hash-algo-id? uint16
| | | +--:(ietf)
| | | +--ro ietf-ni-hash-algo-id? uint8
| | +--ro digest* binary
| +--ro event-size? uint32
| +--ro event-data* uint8
+--:(ima)
+--ro ima-event-logs
+--ro ima-event-entry* [event-number]
+--ro event-number uint64
+--ro ima-template? string
+--ro filename-hint? string
+--ro filedata-hash? binary
+--ro template-hash-algorithm? string
+--ro template-hash? binary
+--ro pcr-index? uint16
+--ro signature? binary
2.2. YANG Module
This YANG module imports modules from [RFC6991], [RFC8348], and
[I-D.ietf-netconf-crypto-types].
<CODE BEGINS> file ietf-tpm-remote-attestation@2019-01-07.yang
module ietf-tpm-remote-attestation {
namespace "urn:ietf:params:xml:ns:yang:ietf-tpm-remote-attestation";
prefix "yang-brat";
import ietf-yang-types {
prefix yang;
}
import ietf-hardware {
prefix ietfhw;
}
import ietf-crypto-types {
prefix ietfct;
}
organization
"IETF RATS (Remote ATtestation procedureS) Working Group";
contact
"WG Web : <http://datatracker.ietf.org/wg/rats/>
WG List : <mailto:rats@ietf.org>
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Author : Henk Birkholz <henk.birkholz@sit.fraunhofer.de>
Author : Michael Eckel <michael.eckel@sit.fraunhofer.de>
Author : Shwetha Bhandari <shwethab@cisco.com>
Author : Bill Sulzen <bsulzen@cisco.com>
Author : Eric Voit <evoit@cisco.com>
Author : Liang Xia (Frank) <frank.xialiang@huawei.com>
Author : Tom Laffey <tom.laffey@hpe.com>
Author : Guy Fedorkow <gfedorkow@juniper.net>";
description
"A YANG module to enable a TPM 2.0 based remote attestation
procedure using a challenge-response interaction model and
the TPM 2.0 Quote primitive operation.
Copyright (c) 2019 IETF Trust and the persons identified
as authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with
or without modification, is permitted pursuant to, and
subject to the license terms contained in, the Simplified
BSD License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC
itself for full legal notices.
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 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.";
revision "2020-01-08" {
description
"Initial version";
reference
"draft-ietf-rats-tpm2-remote-attestation";
}
/*****************/
/* Groupings */
/*****************/
grouping hash-algo {
description
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"A selector for the hashing algorithm";
choice algo-registry-type {
mandatory true;
description
"Unfortunately, both IETF and TCG have registries here.
Choose your weapon wisely.";
case tcg {
description
"you chose the east door, the tcg space opens up to
you.";
leaf tcg-hash-algo-id {
type uint16;
description
"This is an index referencing the TCG Algorithm
Registry based on TPM_ALG_ID.";
}
}
case ietf {
description
"you chose the west door, the ietf space opens up to
you.";
leaf ietf-ni-hash-algo-id {
type uint8;
description
"This is an index referencing the Named Information
Hash Algorithm Registry.";
}
}
}
}
grouping hash {
description
"The hash value including hash-algo identifier";
list hash-digests {
description
"The list of hashes.";
container hash-digest {
description
"A hash value based on a hash algorithm registered by an
SDO.";
uses hash-algo;
leaf hash-value {
type binary;
description
"The binary representation of the hash value.";
}
}
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}
}
grouping nonce {
description
"A nonce to show freshness and counter replays.";
leaf nonce-value {
type binary;
mandatory true;
description
"This nonce SHOULD be generated via a registered
cryptographic-strength algorithm. In consequence, the length
of the nonce depends on the hash algorithm used. The algorithm
used in this case is independent from the hash algorithm used to
create the hash-value in the response of the attestor.";
}
}
grouping tpm12-pcr-selection {
description
"A Verifier can request one or more PCR values using its
individually created Attestation Key Certificate (AC).
The corresponding selection filter is represented in this grouping.
Requesting a PCR value that is not in scope of the AC used, detailed
exposure via error msg should be avoided.";
leaf-list pcr-indices {
type uint8;
description
"The numbers/indexes of the PCRs. At the moment this is limited
to 32.";
}
}
grouping tpm20-pcr-selection {
description
"A Verifier can request one or more PCR values uses its
individually created AC. The corresponding selection filter is
represented in this grouping. Requesting a PCR value that is not
in scope of the AC used, detailed exposure via error msg should
be avoided.";
list pcr-list {
description
"For each PCR in this list an individual list of banks
(hash-algo) can be requested. It depends on the datastore, if
every bank in this grouping is included per PCR (crude), or if
each requested bank set is returned for each PCR individually
(elegant).";
container pcr {
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description
"The composite of a PCR number and corresponding bank
numbers.";
leaf-list pcr-indices {
type uint8;
description
"The number of the PCR. At the moment this is limited
32";
}
uses hash-algo;
}
}
}
grouping pcr-selector {
description
"A Verifier can request the generation of an attestation
certificate (a signed public attestation key
(non-migratable, tpm-resident) wrt one or more PCR values.
The corresponding creation input is represented in this grouping.
Requesting a PCR value that is not supported results in an error,
detailed exposure via error msg should be avoided.";
list pcr-list {
description
"For each PCR in this list an individual hash-algo can be
requested.";
container pcr {
description
"The composite of a PCR number and corresponding bank
numbers.";
leaf-list pcr-index {
type uint8;
description
"The numbers of the PCRs that are associated with
the created key. At the moment the highest number is 32";
}
uses hash-algo;
}
}
}
grouping tpm12-signature-scheme {
description
"The signature scheme used to sign the evidence via a TPM 1.2.";
leaf TPM_SIG_SCHEME-value {
type uint8;
mandatory true;
description
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"Selects the signature scheme that is used to sign the TPM quote
information response. Allowed values can be found in the table at
the bottom of page 32 in the TPM 1.2 Structures specification
(Level 2 Revision 116, 1 March 2011).";
}
}
grouping tpm20-signature-scheme {
description
"The signature scheme used to sign the evidence.";
choice signature-identifier-type {
mandatory true;
description
"There are multiple ways to reference a signature type.
This used to select the signature algo to sign the quote
information response.";
case TPM_ALG_ID {
description
"This references the indices of table 9 in the TPM 2.0
structure specification.";
leaf TPM_ALG_ID-value {
type uint16;
description
"The TPM Algo ID.";
}
}
case COSE_Algorithm {
description
"This references the IANA COSE Algorithms Registry indices.
Every index of this registry to be used must be mapable to a
TPM_ALG_ID value.";
leaf COSE_Algorithm-value {
type int32;
description
"The TPM Algo ID.";
}
}
}
}
grouping tpm12-attestation-key-identifier {
description
"A selector for a suitable key identifier for a TPM 1.2.";
choice key-identifier {
description
"Identifier for the attestation key to use for signing
attestation evidence.";
case public-key {
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leaf pub-key-id {
type binary;
description
"The value of the identifier for the public key.";
}
}
case TSS_UUID {
description
"Use a YANG agent generated (and maintained) attestation
key UUID that complies with the TSS_UUID datatype of the TCG
Software Stack (TSS) Specification, Version 1.10 Golden,
August 20, 2003.";
container TSS_UUID-value {
description
"A detailed structure that is used to create the
TPM 1.2 native TSS_UUID as defined in the TCG Software
Stack (TSS) Specification, Version 1.10 Golden,
August 20, 2003.";
leaf ulTimeLow {
type uint32;
description
"The low field of the timestamp.";
}
leaf usTimeMid {
type uint16;
description
"The middle field of the timestamp.";
}
leaf usTimeHigh {
type uint16;
description
"The high field of the timestamp multiplexed with the
version number.";
}
leaf bClockSeqHigh {
type uint8;
description
"The high field of the clock sequence multiplexed with
the variant.";
}
leaf bClockSeqLow {
type uint8;
description
"The low field of the clock sequence.";
}
leaf-list rgbNode {
type uint8;
description
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"The spatially unique node identifier.";
}
}
}
}
}
grouping tpm20-attestation-key-identifier {
description
"A selector for a suitable key identifier.";
choice key-identifier {
description
"Identifier for the attestation key to use for signing
attestation evidence.";
case public-key {
leaf pub-key-id {
type binary;
description
"The value of the identifier for the public key.";
}
}
case uuid {
description
"Use a YANG agent generated (and maintained) attestation
key UUID.";
leaf uuid-value {
type binary;
description
"The UUID identifying the corresponding public key.";
}
}
}
}
grouping tpm-name {
description
"In a system with multiple-TPMs get the data from a specific TPM
identified by the name and physical-index.";
leaf tpm_name {
type string;
description
"Name of the TPM or All";
}
leaf tpm-physical-index {
if-feature ietfhw:entity-mib;
type int32 {
range "1..2147483647";
}
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config false;
description
"The entPhysicalIndex for the TPM.";
reference
"RFC 6933: Entity MIB (Version 4) - entPhysicalIndex";
}
}
grouping compute-node {
description
"In a distributed system with multiple compute nodes
this is the node identified by name and physical-index.";
leaf node-name {
type string;
description
"Name of the compute node or All";
}
leaf node-physical-index {
if-feature ietfhw:entity-mib;
type int32 {
range "1..2147483647";
}
config false;
description
"The entPhysicalIndex for the compute node.";
reference
"RFC 6933: Entity MIB (Version 4) - entPhysicalIndex";
}
}
grouping tpm12-pcr-info-short {
description
"This structure is for defining a digest at release when the only
information that is necessary is the release configuration.";
uses tpm12-pcr-selection;
leaf locality-at-release {
type uint8;
description
".This SHALL be the locality modifier required to release the
information (TPM 1.2 type TPM_LOCALITY_SELECTION)";
}
leaf digest-at-release {
type binary;
description
"This SHALL be the digest of the PCR indices and PCR values
to verify when revealing auth data (TPM 1.2 type
TPM_COMPOSITE_HASH).";
}
}
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grouping tpm12-version {
description
"This structure provides information relative the version of
the TPM.";
list version {
description
"This indicates the version of the structure
(TPM 1.2 type TPM_STRUCT_VER). This MUST be 1.1.0.0.";
leaf major {
type uint8;
description
"Indicates the major version of the structure.
MUST be 0x01.";
}
leaf minor {
type uint8;
description
"Indicates the minor version of the structure.
MUST be 0x01.";
}
leaf revMajor {
type uint8;
description
"Indicates the rev major version of the structure.
MUST be 0x00.";
}
leaf revMinor {
type uint8;
description
"Indicates the rev minor version of the structure.
MUST be 0x00.";
}
}
}
grouping tpm12-quote-info-common {
description
"These statements are used in bot quote variants of the TPM 1.2";
leaf fixed {
type binary;
description
"This SHALL always be the string 'QUOT' or 'QUO2'
(length is 4 bytes).";
}
leaf external-data {
type binary;
description
"160 bits of externally supplied data, typically a nonce.";
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}
leaf signature-size {
type uint32;
description
"The size of TPM 1.2 'signature' value.";
}
leaf signature {
type binary;
description
"Signature over SHA-1 hash of tpm12-quote-info2'.";
}
}
grouping tpm12-quote-info {
description
"This structure provides the mechanism for the TPM to quote the
current values of a list of PCRs (as used by the TPM_Quote2
command).";
uses tpm12-version;
leaf digest-value {
type binary;
description
"This SHALL be the result of the composite hash algorithm using
the current values of the requested PCR indices
(TPM 1.2 type TPM_COMPOSITE_HASH.)";
}
}
grouping tpm12-quote-info2 {
description
"This structure provides the mechanism for the TPM to quote the
current values of a list of PCRs
(as used by the TPM_Quote2 command).";
leaf tag {
type uint8;
description
"This SHALL be TPM_TAG_QUOTE_INFO2.";
}
uses tpm12-pcr-info-short;
}
grouping tpm12-cap-version-info {
description
"TPM returns the current version and revision of the TPM 1.2 .";
list TPM_PCR_COMPOSITE {
description
"The TPM 1.2 TPM_PCRVALUEs for the pcr-indices.";
uses tpm12-pcr-selection;
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leaf value-size {
type uint32;
description
"This SHALL be the size of the 'tpm12-pcr-value' field
(not the number of PCRs).";
}
leaf-list tpm12-pcr-value {
type binary;
description
"The list of TPM_PCRVALUEs from each PCR selected in sequence
of tpm12-pcr-selection.";
}
list version-info {
description
"An optional output parameter from a TPM 1.2 TPM_Quote2.";
leaf tag {
type uint16;
description
"The TPM 1.2 version and revision
(TPM 1.2 type TPM_STRUCTURE_TAG).
This MUST be TPM_CAP_VERSION_INFO (0x0030)";
}
uses tpm12-version;
leaf spec-level {
type uint16;
description
"A number indicating the level of ordinals supported.";
}
leaf errata-rev {
type uint8;
description
"A number indicating the errata version of the
specification.";
}
leaf tpm-vendor-id {
type binary;
description
"The vendor ID unique to each TPM manufacturer.";
}
leaf vendor-specific-size {
type uint16;
description
"The size of the vendor-specific area.";
}
leaf vendor-specific {
type binary;
description
"Vendor specific information.";
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}
}
}
}
grouping tpm12-pcr-composite {
description
"The actual values of the selected PCRs (a list of TPM_PCRVALUEs
(binary)and associated metadata for TPM 1.2.";
list TPM_PCR_COMPOSITE {
description
"The TPM 1.2 TPM_PCRVALUEs for the pcr-indices.";
uses tpm12-pcr-selection;
leaf value-size {
type uint32;
description
"This SHALL be the size of the 'tpm12-pcr-value' field
(not the number of PCRs).";
}
leaf-list tpm12-pcr-value {
type binary;
description
"The list of TPM_PCRVALUEs from each PCR selected in sequence
of tpm12-pcr-selection.";
}
}
}
grouping node-uptime {
description
"Uptime in seconds of the node.";
leaf up-time {
type uint32;
description
"Uptime in seconds of this node reporting its data";
}
}
identity log-type {
description
"The type of logs available.";
}
identity bios {
base log-type;
description
"Measurement log created by the BIOS/UEFI.";
}
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identity ima {
base log-type;
description
"Measurement log created by IMA.";
}
grouping log-identifier {
description
"Identifier for type of log to be retrieved.";
leaf log-type {
type identityref {
base log-type;
}
mandatory true;
description
"The corresponding measurement log type identity.";
}
}
grouping boot-event-log {
description
"Defines an event log corresponding to the event that extended the
PCR";
leaf event-number {
type uint32;
description
"Unique event number of this event";
}
leaf event-type {
type uint32;
description
"log event type";
}
leaf pcr-index {
type uint16;
description
"Defines the PCR index that this event extended";
}
list digest-list {
description "Hash of event data";
uses hash-algo;
leaf-list digest {
type binary;
description
"The hash of the event data";
}
}
leaf event-size {
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type uint32;
description
"Size of the event data";
}
leaf-list event-data {
type uint8;
description
"the event data size determined by event-size";
}
}
grouping ima-event {
description
"Defines an hash log extend event for IMA measurements";
leaf event-number {
type uint64;
description
"Unique number for this event for sequencing";
}
leaf ima-template {
type string;
description
"Name of the template used for event logs
for e.g. ima, ima-ng";
}
leaf filename-hint {
type string;
description
"File that was measured";
}
leaf filedata-hash {
type binary;
description
"Hash of filedata";
}
leaf template-hash-algorithm {
type string;
description
"Algorithm used for template-hash";
}
leaf template-hash {
type binary;
description
"hash(filedata-hash, filename-hint)";
}
leaf pcr-index {
type uint16;
description
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"Defines the PCR index that this event extended";
}
leaf signature {
type binary;
description
"The file signature";
}
}
grouping bios-event-log {
description
"Measurement log created by the BIOS/UEFI.";
list bios-event-entry {
key event-number;
description
"Ordered list of TCG described event log
that extended the PCRs in the order they
were logged";
uses boot-event-log;
}
}
grouping ima-event-log {
list ima-event-entry {
key event-number;
description
"Ordered list of ima event logs by event-number";
uses ima-event;
}
description
"Measurement log created by IMA.";
}
grouping event-logs {
description
"A selector for the log and its type.";
choice log-type {
mandatory true;
description
"Event log type determines the event logs content.";
case bios {
description
"BIOS/UEFI event logs";
container bios-event-logs {
description
"This is an index referencing the TCG Algorithm
Registry based on TPM_ALG_ID.";
uses bios-event-log;
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}
}
case ima {
description
"IMA event logs";
container ima-event-logs {
description
"This is an index referencing the TCG Algorithm
Registry based on TPM_ALG_ID.";
uses ima-event-log;
}
}
}
}
/**********************/
/* RPC operations */
/**********************/
rpc tpm12-challenge-response-attestation {
description
"This RPC accepts the input for TSS TPM 1.2 commands of the
managed device. ComponentIndex from the hardware manager YANG
module to refer to dedicated TPM in composite devices,
e.g. smart NICs, is still a TODO.";
input {
container tpm1-attestation-challenge {
description
"This container includes every information element defined
in the reference challenge-response interaction model for
remote attestation. Corresponding values are based on
TPM 1.2 structure definitions";
uses tpm12-pcr-selection;
uses nonce;
uses tpm12-signature-scheme;
uses tpm12-attestation-key-identifier;
leaf add-version {
type boolean;
description
"Whether or not to include TPM_CAP_VERSION_INFO; if true,
then TPM_Quote2 must be used to create the response.";
}
uses tpm-name;
}
}
output {
list tpm12-attestation-response {
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key tpm_name;
description
"The binary output of TPM 1.2 TPM_Quote/TPM_Quote2, including
the PCR selection and other associated attestation evidence
metadata";
uses tpm-name;
uses node-uptime;
uses compute-node;
uses tpm12-quote-info-common;
choice tpm12-quote {
mandatory true;
description
"Either a tpm12-quote-info or tpm12-quote-info2, depending
on whether TPM_Quote or TPM_Quote2 was used
(cf. input field add-verson).";
case tpm12-quote1 {
description
"BIOS/UEFI event logs";
uses tpm12-quote-info;
uses tpm12-pcr-composite;
}
case tpm12-quote2 {
description
"BIOS/UEFI event logs";
uses tpm12-quote-info2;
}
}
}
}
}
rpc tpm20-challenge-response-attestation {
description
"This RPC accepts the input for TSS TPM 2.0 commands of the
managed device. ComponentIndex from the hardware manager YANG
module to refer to dedicated TPM in composite devices,
e.g. smart NICs, is still a TODO.";
input {
container tpm20-attestation-challenge {
description
"This container includes every information element defined
in the reference challenge-response interaction model for
remote attestation. Corresponding values are based on
TPM 2.0 structure definitions";
uses tpm20-pcr-selection;
uses nonce;
uses tpm20-signature-scheme;
uses tpm20-attestation-key-identifier;
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}
list tpms {
key tpm_name;
description
"TPMs to fetch the attestation information.";
uses tpm-name;
}
}
output {
list tpm20-attestation-response {
key tpm_name;
description
"The binary output of TPM2b_Quote. An TPMS_ATTEST structure
including a length, encapsulated in a signature";
uses tpm-name;
uses node-uptime;
uses compute-node;
container tpms-attest {
leaf pcrdigest {
type binary;
description
"split out value of TPMS_QUOTE_INFO for convenience";
}
leaf tpms-attest-result {
type binary;
description
"The complete TPM generate structure including
signature.";
}
leaf tpms-attest-result-length {
type uint32;
description
"Length of attest result provided by the TPM structure.";
}
description
"A composite of value and length and list of selected
pcrs (original name: [type]attested)";
}
leaf tpmt-signature {
type binary;
description
"Split out value of the signature for convenience.
TODO: check for length values that complent binary value
data node leafs.";
}
}
}
}
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rpc basic-trust-establishment {
description
"This RPC creates a tpm-resident, non-migratable key to be used
in TPM_Quote commands, an attestation certificate.";
input {
uses nonce;
uses tpm20-signature-scheme;
uses tpm-name;
leaf certificate-name {
type string;
description
"An arbitrary name for the identity certificate chain
requested.";
}
}
output {
list attestation-certificates {
key tpm_name;
description
"Attestation Certificate data from a TPM identified by the TPM
name";
uses tpm-name;
uses node-uptime;
uses compute-node;
leaf certificate-name {
type string;
description
"An arbitrary name for this identity certificate or
certificate chain.";
}
leaf attestation-certificate {
type ietfct:end-entity-cert-cms;
description
"The binary signed certificate chain data for this identity
certificate.";
}
uses tpm20-attestation-key-identifier;
}
}
}
rpc log-retrieval {
description
"Logs Entries are either identified via indices or via providing
the last line received. The number of lines returned can be
limited. The type of log is a choice that can be augmented.";
input {
list log-selector {
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key node-name;
description
"Selection of log entries to be reported.";
uses compute-node;
choice index-type {
description
"Last log entry received, log index number, or timestamp.";
case last-entry {
description
"The last entry of the log already retrieved.";
leaf last-entry-value {
type binary;
description
"Content of an log event which matches 1:1 with a
unique event record contained within the log. Log
entries subsequent to this will be passed to the
requester. Note: if log entry values are not unique,
this MUST return an error.";
}
}
case index {
description
"Numeric index of the last log entry retrieved, or zero.";
leaf index-number {
type uint64;
description
"The numeric index number of a log entry. Zero means
to start at the beginning of the log. Entries
subsequent to this will be passed to the
requester.";
}
}
case timestamp {
leaf timestamp {
type yang:date-and-time;
description
"Timestamp from which to start the extraction. The next
log entry subsequent to this timestamp is to be sent.";
}
description
"Timestamp from which to start the extraction.";
}
}
}
uses log-identifier;
uses tpm20-pcr-selection;
leaf log-entry-quantity {
type uint16;
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description
"The number of log entries to be returned. If omitted, it
means all of them.";
}
}
output {
container system-event-logs {
description
"The requested data of the measurement event logs";
list node-data {
key "node-name tpm_name";
description
"Event logs of a node in a distributed system
identified by the node name";
uses compute-node;
uses node-uptime;
uses tpm-name;
container log-result {
description
"The requested entries of the corresponding log.";
uses event-logs;
}
}
}
}
}
/*********************************/
/* Protocol accessible nodes */
/*********************************/
container rats-support-structures {
config false;
description
"The datastore definition enabling verifiers or relying
parties to discover the information necessary to use the
remote attestation RPCs appropriately.";
leaf-list supported-algos {
type uint16;
description
"Supported TPM_ALG_ID values for the TPM in question.
Will include ComponentIndex soon.";
}
list tpms {
key tpm_name;
uses tpm-name;
description
"A list of TPMs in this composite
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device that rats can be conducted with.";
list certificates {
container certificate {
leaf certificate-name {
type string;
description
"An arbitrary name for this identity certificate or
certificate chain.";
}
leaf certificate-type {
type enumeration {
enum endorsement-cert {
value 0;
description
"An endorsement key certificate.";
}
enum attestation-cert {
value 1;
description
"An attestation key certificate.";
}
}
description
"Type of this certificate";
}
leaf certificate-value {
type ietfct:end-entity-cert-cms;
description
"The binary signed public endorsement key (EK),
attestation key (AK) and corresponding claims (EK or
AK Certificate). In a TPM 2.0 the EK,AK Certificate
resides in a well-defined NVRAM location by the TPM
vendor.";
}
description
"The list of certificates each TPM can be distinguished with.";
}
description
"The TPM's endorsement-certificate.";
}
}
list compute-nodes {
key node-name;
uses compute-node;
description
"A list names of hardware components in this composite
device that rats can be conducted with.";
}
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}
}
<CODE ENDS>
3. IANA considerations
This document will include requests to IANA:
To be defined yet.
4. Security Considerations
There are always some.
5. Acknowledgements
Not yet.
6. Change Log
Changes from version 00 to version 01:
o Addressed author's comments
o Extended complementary details about attestation-certificates
o Relabeled chunk-size to log-entry-quantity
o Relabeled location with compute-node or tpm-name where appropriate
o Added a valid entity-mib physical-index to compute-node and tpm-
name to map it back to hardware inventory
o Relabeled name to tpm_name
o Removed event-string in last-entry
7. References
7.1. Normative References
[I-D.birkholz-rats-reference-interaction-model]
Birkholz, H. and M. Eckel, "Reference Interaction Model
for Challenge-Response-based Remote Attestation", draft-
birkholz-rats-reference-interaction-model-01 (work in
progress), July 2019.
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[I-D.ietf-netconf-crypto-types]
Watsen, K. and H. Wang, "Common YANG Data Types for
Cryptography", draft-ietf-netconf-crypto-types-13 (work in
progress), November 2019.
[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>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8348] Bierman, A., Bjorklund, M., Dong, J., and D. Romascanu, "A
YANG Data Model for Hardware Management", RFC 8348,
DOI 10.17487/RFC8348, March 2018,
<https://www.rfc-editor.org/info/rfc8348>.
7.2. Informative References
[I-D.ietf-rats-architecture]
Birkholz, H., Thaler, D., Richardson, M., and N. Smith,
"Remote Attestation Procedures Architecture", draft-ietf-
rats-architecture-00 (work in progress), December 2019.
Authors' Addresses
Henk Birkholz
Fraunhofer SIT
Rheinstrasse 75
Darmstadt 64295
Germany
Email: henk.birkholz@sit.fraunhofer.de
Michael Eckel
Fraunhofer SIT
Rheinstrasse 75
Darmstadt 64295
Germany
Email: michael.eckel@sit.fraunhofer.de
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Shwetha Bhandari
Cisco Systems
Email: shwethab@cisco.com
Bill Sulzen
Cisco Systems
Email: bsulzen@cisco.com
Eric Voit
Cisco Systems
Email: evoit@cisco.com
Liang Xia (Frank)
Huawei Technologies
101 Software Avenue, Yuhuatai District
Nanjing, Jiangsu 210012
China
Email: Frank.Xialiang@huawei.com
Tom Laffey
Hewlett Packard Enterprise
Email: tom.laffey@hpe.com
Guy C. Fedorkow
Juniper Networks
10 Technology Park Drive
Westford, Massachusetts 01886
Email: gfedorkow@juniper.net
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