Internet-Draft DRIP DKI November 2024
Moskowitz & Card Expires 19 May 2025 [Page]
Workgroup:
INTAREA
Internet-Draft:
draft-ietf-drip-dki-03
Published:
Intended Status:
Informational
Expires:
Authors:
R. Moskowitz
HTT Consulting
S. Card
AX Enterprize, LLC

The DRIP DET public Key Infrastructure

Abstract

The DRIP Entity Tag (DET) public Key Infrastructure (DKI) is a specific variant of classic Public Key Infrastructures (PKI) where the organization is around the DET, in place of X.520 Distinguished Names. Further, the DKI uses DRIP Endorsements in place of X.509 certificates for establishing trust within the DKI.

There are two X.509 profiles for shadow PKI behind the DKI, with many of their X.509 fields mirroring content in the DRIP Endorsements. This PKI can at times be used where X.509 is expected and non-constrained communication links are available that can handle their larger size.

C509 (CBOR) encoding of all X.509 certificates are also provided as an alternative for where there are gains in reduced object size.

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 19 May 2025.

Table of Contents

1. Introduction

A DRIP Entity Tag (DET, [RFC9374]) public Key Infrastructure (DKI) is designed as a strict hierarchy, governed by the administrator of the DET prefix [IPv6-SPECIAL] and having the authority to authorize RAAs. RAAs in turn authorize HDAs within their domain. This authorization is managed via a set of DETs whose sole use is to define the DKI. The RAA Authorization DETs MUST reside in HID = RAA#|0 (Apex Authorization DET in HID = 0|0).

There are three main classifications/types of DETs:

All DETs exist in DET-Endorsements (Appendix B of [drip-registries]). These DET-Endorsements provide the proof of registration and thus trust. These DETs, through chained Endorsements define the DKI as follows:


                +----------+
                |   Auth   |
                +-o------o-+
                  |      |
                  |    +-o-----+
 Apex             |   +--o----+|
                  |   | Issue |+
                  |   +---o---+
                  |      |
                  |    +-o-----+
                  |   +--o----+|
                  |   |CRL,Srv|+
                  |   +-------+
                  |
******************|************************************
                +-o--------+
               +-o--------+|
               |   Auth   |+
               +--o-----o-+
                  |     |
                  |   +-o-----+
 RAAs             |  +--o----+|
                  |  | Issue |+
                  |  +---o---+
                  |     |
                  |   +-o--------+
                  |  +--o-------+|
                  |  |  CRL,Srv |+
                  |  |Oper,Pilot|+
                  |  +----------+
                  |
******************|************************************
                +-o--------+
               +-o--------+|
               |   Auth   |+
               +----o-----+
                    |
                  +-o-----+
 HDAs            +--o----+|
                 | Issue |+
                 +---o---+
                     |
                   +-o-------+
                  +--o------+|
                  | CRL,Srv ||
                  |   UAS   |+
                  +---------+

*******************************************************

Figure 1: The DKI Endorsements

The Authorization DETs exist in a set of DET-Authorization-Endorsements. The lifetime of these endorsements SHOULD be no less than 1 year, recommended 5 years, and should not exceed 10 years. Endorsements SHOULD be reissued prior to expiry (may be for a new DET). DETs used to define this authorization are replaced per undetermined policy (note these DETs do very little signing, see Section 7.1).

This separation of DET type roles reduce the risk of private key loss for the critical Authentication DETs by making them infrequently used and only used in offline operations. It does make the chain of trust for a HDA customers' Operational DETs to be 4 Endorsements.

1.1. The DKI without an Apex Entity

The hierarchical design of the DKI is the most efficient possible with the least data transmission overhead. But it requires the participation of an Entity, in the role of the Apex, trusted by all the RAAs. The logical Entity for this role is the International Civil Aviation Authority (ICAO), but the processes for ICAO to take on this role are complex. Work is ongoing with the ICAO, but timing is indeterminate and immediately implementable alternatives are needed.

The DKI can work by the RAAs establishing mutual trust within a geographic region. It is envisioned that the initial RAA assignments will follow Section 6.2.1 of [drip-registries], Table 1. Without an Apex, each RAA self-endorses its Authentication DET, acting as its own apex. However, RAAs issued DETs (via their HDAs) will not exist in the air by themselves (except perhaps for some small island nations), thus a geographic regional consortium of RAAs will need to deploy some mechanism for mutual trust for their End Entities to fly together.

There are three reasonable approaches for RAAs to manage their mutual trust and it is likely that all will occur:

    1. RAA Trust lists
    2. RAA Cross-endorsements
    3. Bridge RAA with cross-endorsements to RAAs

It is recommended that the RAA Trust List be used during initial DKI testing. The cross-endorsing options will need their own testing to work out how best to deploy them.

1.1.1. RAA Trust lists

A consortium of RAAs MAY choose to maintain a list of RAAs they trust. It is recommended that this list consist of the RAA's Authentication DET and HI. Each RAA in the consortium SHOULD maintain its own list, signed with its Authentication DET.

This Trust List MAY contain each RAA's Authentication DET self-endorsement validity dates. If a trusted RAA has more than one self-endorsement (most likely to support key rollover), including these dates makes it easier to have an RAA duplicated in the list.

How the RAAs communicate between themselves to maintain these lists is out of scope here. Each RAA SHOULD include validity dates in its Trust List. Frequency of Trust List updates is also out of scope here.

Trust Lists is the simplest method to implement, but may not be the simplest to maintain over time.

There is a natural Trust List of ALL RAAs, based on what is allocated in the DRIP DNS tree.

1.1.2. RAA Cross-endorsements

A consortium of RAAs MAY choose to cross-endorse each's Authentication DET. This is done by one RAA endorsing for its community, an other's Authentication DET. This establishes one-way trust; thus, in practice, each RAA needs to cross-endorse each RAA's Authentication DET within the consortium.

RAA Cross-endorsements definitely has a scaling (n^2) problem. It works for a starting point or for a very small group of RAAs.

How these RAA Cross-endorsements are discovered has not been defined at this point. One potential is via a to-be-defined DNS HHIT RR within the endorsing RAA's zone. This information would need to be cached by any potential offline entity.

1.1.3. Bridge RAA with cross-endorsements to RAAs

A consortium of RAAs MAY select one RAA to function as a "Bridge" between all members of the consortium. In this approach, the "Bridge RAA" does not authorize any sub-HDAs. Its sole purpose is the cross-endorse to member RAAs. The Bridge and each RAA cross endorse as in Section 1.1.2.

Bridge RAA Cross-endorsementing reduces the scaling challenge to only the number of RAAs in the consortium. Plus there is little need to communicate any changes in the cross-endorsementing to the various parties within the consortium. Thus this option scales the best out of the three alternatives to DKI Apex hierarchy.

How these RAA Cross-endorsements are discovered has not been defined at this point. The Bridge RAA will have to be known to all parties within the consortium. One potential, as above, is via a to-be-defined DNS HHIT RR (Appendix A of [drip-registries]) within the endorsing RAA's zone. This information would need to be cached by any potential offline entity.

1.2. The C509 encoding of X.509 Certificates

A price in object size is paid in the ASN.1 encoding of X.509 certificates. This is often a barrier for use over constrained links and even storage demands on constrained processing platforms. The [C509-Certificates] provides an alternative encoding in two different manners:

    1. An invertible CBOR re-encoding of DER encoded X.509 certificates [RFC5280], which can be reversed to obtain the original DER encoded X.509 certificate.
    2. Natively signed C509 certificates, where the signature is calculated over the CBOR encoding instead of over the DER encoding as in 1. This removes the need for ASN.1 and DER parsing and the associated complexity but they are not backwards compatible with implementations requiring DER encoded X.509.

The invertible CBOR encoding is recommended for use here. This can be readily implemented through libraries that do the translation, as needed, between X.509 and c509.

2. Terms and Definitions

2.1. Requirements Terminology

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.

2.2. Definitions

This document uses the terms defined in Section 2.2 of Drip Requirements and Terminology [RFC9153] and in Section 2 of Drip Architecture [RFC9434]. The following new terms are used in the document:

Authorization DETs
DETs whose use is to define a hierarchy level and endorse lower hierarchy level Authorization DETs and finally Issuing DETs at this hierarchy level. They the DETs in the Authentication Endorsements and X.509 certificates.
DKI
A DRIP Entity Tag (DET) public Key Infrastructure. Similar to an X.509 PKI, but built on the DRIP Endorsements.
International Aviation Trust Framework (IATF)
The ICAO IATF is comprised of a set of policies, requirements, and best practices that will enable resilient and secured ground-ground, air-ground, and air-air exchange of digital information, and among both traditional and newly-emerging system stakeholders.
Issuing DETs
DETs whose use is to sign Endorsements and X.509 certificates for Operational DETs that are at the same hierarchy level as the Issuing DET.
Operational DETs
DETs used by various entities in DRIP protocols and as non-routable IPv6 addresses. A partial list of such entities includes: GCS, Infrastructure (e.g. wireless tower systems), UAS Operators, Pilots-in-command, Servers, UA.
​System Wide Information Management (SWIM)
The ICAO SWIM consists of Standards, Infrastructure and Governance enabling the management of Air Navigation Systems (ANS) related information and its exchange between qualified parties via interoperable services.

3. The DET public Key Infrastructure (DKI)

3.1. The DKI Levels

3.1.1. The Apex

The Apex Authorization DET is used to endorse RAA Authorization DETs and its own Apex Issuing DETs; it has no other use. This is the case for all Authorization DETs. Apex Issuing DETs are used to endorse DETs, with HID= 0|0, used by Apex services.

The DET Apex may be only theoretical if no Entity steps forward to provide this role.

3.1.2. The RAAs

Each RAA use its Authorization DET (HID = RAA#|0) to endorse its RAA Issuing DET(s) (also HID = RAA#|0) and for signing its HDA Authorization DETs (HID = RAA#|HDA#).

An RAA may have multiple Issuing DETs (HID = RAA#|0), each for a different use (e.g. CRL signing, RAA server signing). It is expected that, over time, an RAA will rollover its Issuing DETs, thus at times there will be more than ONE Issuing DET per role in use.

These Issuing DETs, like those at the Apex level, constitute an implicit HDA. There is no Authorization DET for this implicit HDA, but other than only signing for entities like servers needed by the RAA, it should be considered as an HDA in terms of policies.

The initial RAA range assignments are defined in Section 6.2.1 of [drip-registries], Table 1. It is anticipated that DRIP usage will expand to use into General/Civil Aviation. Thus at some point a block of RAAs will be set aside much like for the CTA-2063A [CTA2063A] range.

3.1.3. The HDAs

Each HDA use its Authorization DET to endorse its HDA Issuing DETs (e.g. RAA=267, HDA=567).

An HDA Issuing DET is used to endorse Operational DETs; those used by the HDA for its services (e.g. USS) and for Devices (e.g. UA, GCS, ground infrastructure) partaking in the HDA's services.

If the Operational DET is a Manufacturer DET, the "valid not after" date (vna) MUST be 99991231235959Z.

3.2. The Offline Requirement for Authentication DETs

The Authentication DETs private keys MUST NEVER be on a system with any network connectivity. Also efforts MUST be taken to limit any external digital media connections to these offline systems. Compromise of an Authentication DET compromises its and all lower hierarchy levels. Such a compromise could result in a major re-signing effort with a new Authentication DET. Also, during the time of compromise, fraudulent additions to the DKI could have occurred.

This means that the process whereby the Authentication DET is used to sign the Endorsement/X.509 certificate of its level's Issuing DET(s) and lower level Authentication DETs MUST be conducted in an offline manner.

This offline process need not be onerous. For example, QR codes could be used to pass CSR objects to the offline Authentication DET system, and this system could produce QR codes containing the Endorsements and X.509 certificates it signed.

A video conference between the parties could have one side show its QR code and the other copy and print it to move between the video conferencing system and the offline system. This is a simplification of a larger signing operation, but shows how such a signing need not require travel and expensive hand-off methodologies.

It should be noted that the endorsement of Issuing DETs follow the same restriction, as it is done with the Authentication DET. It MUST be conducted in an offline manner.

3.3. DNS view of DKI

The primary view of the DKI is within DNS. This is in the 3.0.0.1.0.0.2.ip6.arpa zone (Apex level of the DRIP IPv6 DET format).

In the DET DNS structure, only the Apex and RAA levels MUST be DNSSEC signed. The HDA level may be too dynamic for DNSSEC signing (e.g. hundreds of new EE Operational DETs per hour); trust in the EE Operational DETs within the HDA level comes through inclusion of the HDA Endorsement of EE object. A slow-churn HDA MAY use DNSSEC. The RAA and HDA levels MUST contain their Endorsement by higher object; this provides the needed trust in the Endorsement of EE objects. The Apex level Endorsement is self-signed, thus trust in it is only possible via DNSSEC.

Endorsements are expected to be stored in DNS HHIT RR (Appendix A of [drip-registries]) will soon provide an alternative and specifically designed RR for this purpose. Other RR within these levels will vary. There also may be HIP, TLSA, and/or URI RR.

Each level continues on down the 3.0.0.1.0.0.2.ip6.arpa zone for its Authorization DET and Issuing DET(s). RR with FQDNs for services offered may also be present in various forms (e.g. a URI for the commercial FQDN for the DKI Entity). TLSA RR of DET SPKI may be directly included here. Same with HIP RR. The Authorization Endorsement SHOULD be present, as SHOULD be Issuing Endorsements.

3.4. Managing DET Revocation

For Operational DETs, there is no direct concept of DET revocation. Operational DETs are either discoverable via DNS or not valid despite being in a non-expired Endorsement signed an Issuing DET. Thus if an Issuing Entity needs to "revoke" an Operational DET it removes all entries for it from DNS, so a short TTL on those records is recommended.

Authorization and Issuing DETs are not so easily "revoked"; something akin to an X.509 CRL mechanism is needed. This could best be dealt with by Endorsements managed in the new DET RR that includes revocation status. Thus Appendix A of [drip-registries] defines the specific RR for Endorsements that will be used here. Minimally, at least the revocation status and revocation date(s) need to be in this RR. Until this RR is available, there is no mechanism, other than removal for Authorization and Issuing DET revocations.

3.5. The Offline cache of HDA Issuing Endorsements

The Offline cache of HDA Issuing Endorsements, used to verify various EE signed objects without needing DNS access, SHOULD consist of the HDA Authentication DET Endorsements of the HDA Issuing DETs. Thus the receiver has a trusted source of the HDA Issuing DET Public Key (HI) in a DRIP standard object (136 bytes). If the DKI DNS tree includes GEO location data and coverage, a receiver could query some service for a trusted cache within some radius of its location. Such as, please tell me of all HDAs within 100KM of...

This cache MAY contain the full chain up to the Apex. This could be helpful in limited connectivity environments when encountering an HDA Issuing DET under a unknown Authenticated HDA or RAA. The needed trust chain could be shorter.

3.5.1. HDA Offline Trust cache

There are situations where a list of specific HDAs for an entity to trust for some application is needed. This can best be met by maintaining a cache as above but only of the trusted HDA Issuing Endorsements. How a list of this limited trust is maintain and distributed is out of scope of this document and is left to those needing this specific feature.

4. The DKI's Shadow PKI

The following defines the components of a DKI's shadow PKI built from X.509 certificates with content that mirrors that in the DKI Endorsements. There are two profiles provided; both may be used, or the community may select one for deployment. In both cases, the PKI tree mirrors that of the DKI levels (Section 3.1).

At this point in defining the shadow PKIs, alternatives to a strict hierarchy is still an open work item. This work will follow the pattern set in Section 1.1.

4.1. Shadow Lite-PKI with minimal content Certificates

The Lite-PKI is designed to fully mirror the DKI in the smallest reasonable X.509 certificates (e.g. 240 bytes for DER), but still adhere to [RFC5280] MUST field usage.

4.1.1. DRIP Lite X.509 certificate profile

The following is the profile for the DRIP X.509 Lite certificates


Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
        Signature Algorithm: ED25519
        Issuer: CN =
        Validity
            Not Before:
            Not After :
        Subject: {CN = or Empty}
        Subject Public Key Info:
            Public Key Algorithm: ED25519
                ED25519 Public-Key:
                pub:
        X509v3 extensions: {Operation Certs ONLY}
            X509v3 Subject Alternative Name: critical
                IP Address:
    Signature Algorithm: ED25519
    Signature Value:

Figure 2: The X.509 Lite Profile

4.1.2. DRIP Lite Manditory Certificate Content

The following detail the Manditory to include content in all DRIP Lite certificates.

4.1.2.1. Serial Number

The Serial Number is a MUST field, but it has no usage in this Lite-PKI. It is 1-byte in size and thus duplicates are guaranteed. To drop this field could make many X.509 parsing libraries fail.

However, CA certificate's Serial Number MAY be the common 20 bytes. This is to avoid possible issues with general softward expecting this size Serial Numbers for CAs.

4.1.2.2. Subject

The Subject field is only used in Authentication and Issuing Certificates. For Entity Certificates, the Subject is Empty and the DET will be in Subject Alternative Name (SAN). In the SAN, the DET can be properly encoded as an IPv6 address.

The Subject field in Authentication and Issuing Certificates uses the following format:


DRIP-{APEX|RAA|HDA}-{A|I}[-RAA#][-HDA#]

Examples:

    DRIP-RAA-A-16376
    DRIP-HDA-I-16376-16376


Figure 3: Lite CA Certificate Subject Name Format

The CA Subject Name serves a duo purpose: foremostly, to place the CA within the DKI tree, but secondly for outside of DRIP usage to tag that this CA's function is to serve DRIP Entities.

4.1.2.3. Subject Alternative Name

Subject Alternative Name is only used in Operational (End Entity) certificates. It is used to provide the DET as an IP address with an Empty Subject (SAN MUST be flagged as Critical).

The Subject Alternative Name is also used in Manufacturer DET certificates. These may contain the hardwareModuleName as described in [IEEE 802.1AR] that references [RFC4108].

Per [RFC5280] and [IEEE 802.1AR], Manufacturer DET certificates with hardwareModuleName MUST have the notAfter date as 99991231235959Z.

4.1.2.4. Issuer

The Issuer MUST be the higher level's DET.

The Issuer for the Apex Authentication certificate MUST be the Subject (indicating self-signed).

The Issuer content of its DET assists in finding this specific Issuer in the DRIP ip6.arpa. DNS tree and any additional information.

4.1.2.5. The test DKI and Lite PKI

The test DKI and Lite PKI, (Appendix A/Appendix B), were created using the python scripts at [drip_scripts]. First csr-gen.py is used to create an X.509 CSR (and optionally the EdDSA keypair). This CSR is minimal in content. For example, a UA might only have knowledge of its Manufacturer Serial Number and can generate its keypair. Per [drip-registration-cwt], this CSR may be sent to the CA with additional information provided by the Operator, for example desired validityDates. The raa-endorse.py and hda-endorse.py scripts are provided to produce the DRIP Endorsements and X.509 certificates.

At this time, with no Apex level, each RAA Authorization CA is self-signed. These are created using the RAA's CSR and its own keypair as input to the raa-endorse.py script. Normally, the raa-endorse.py script is used to create the HDA's Authorization and Issuing CAs and the hda-endorse.py script for the End Entity certificates.

4.1.3. DRIP Lite Optional CA Certificate Content

The following detail the Optional content for DRIP Lite CA certificates. Inclusion of these objects are based on the policies of the CA using them and CAs higher in the trust chain.

4.1.3.1. CA Subject Alternative Name URI

This is the one exception to Section 4.1.2.3. A CA certificate MAY have a SAN URI, containing a pointer where additional information on the CA and certificates under its control. For example, an authorized authority may access EE PII like an Oberator phone number through this URI link.

4.1.3.2. CA Policy OIDs

The CA MAY have policy OIDs defining rules for EEs within its domain. The OIDs used here will tend to be within ICAO's arc of 1.3.9.16.

4.2. Abandoned: Shadow PKI with PKIX-like Certificates

Author's Note: The PKIX-like Certificate model has been abandoned for now due to lack of interest in these larger ~400 bytes for DER) size. For information on these certificates, please review the first draft of this document.

5. The DKI and the ICAO IAC PKI

The ICAO has defined an International Aviation Common PKI (IAC) PKI in their ICAO Doc 10169 Aviation Common Certificate Policy (ACCP). A test version of this PKI is rolling out for testing the Aviation System Wide Information Management (SWIM) environment.

Currently, this PKI is using ECDSA P-256 in its certificates. This is equivalent to DET SuiteID of "3". The subjectNames in use can readily by mapped to RAAs (Section 6.2.1 of [drip-registries], Table 1) and HDAs. Thus it is a potential straight-forward technical work item to add DET support into the PKI.

The DETs can readily be stored in subjectAltName or more interestingly in subjectKeyIdentifier (and thus authorityKeyIdentifier).

There are a number of advantages in the IATF and SWIM to have DETs and the matching DNS available. For example, the "cost" of adding DETs to these certificates could result in moving much of their content into DNS SRV RR and potentially reduce their size by 1/3rd. DETs as the authorityKeyIdentifier would enable DNS for Trust Chain discovery.

Another approach is direct inclusion in this PKI of the DET "Lite" EE certificates for constrained A2A communications.

Discussions are ongoing with those involved with the IATF PKI and this could open up DET usage into General/Civil Aviation.

6. IANA Considerations

TBD

7. Security Considerations

Risks in the DKI are similar to those in any X.509 PKI. The methodologies to mitigate risk in PKI management should be considered and implemented as appropriate.

The DKI presents a tree-breath problem that is rarely seen in PKIs and needs practical solutions to minimize cost of operations and not introduce risks needlessly. Consider that there can be 16,384 RAAs. Assume only 10,000 RAAs, each of which Authentication DET Endorsement has a 10 year validity period. This means that, on average, 1,000 RAAs per year need to rekey their Authentication DET Endorsement, or on average, 3 per day. Current witnessed key signing processes will not scale to this volume. Some virtual method (like in Section 3.2) is needed.

7.1. Protecting against DKI/PKI compromise

There is always a risk of key compromise that could be a major setback to the operation of a PKI and likewise the DRIP DKI. To mitigate this risk, the Authentication DETs MUST only be used in offline signing operations. They MUST NEVER be used on connected systems. The information needed to create the Endorsements and X.509 certificates are brought to them on media that cannot transfer code, for example in a QR code. The objects that are created are then transferred away from the offline system to be used where needed.

It should be noted that this offline process MUST be followed down the DKI/PKI tree. That is, the Apex has offline operations that include signing the RAA Authentication DET that will be used in the RAA's set up.

8. References

8.1. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.

8.2. Informative References

[C509-Certificates]
Mattsson, J. P., Selander, G., Raza, S., Höglund, J., and M. Furuhed, "CBOR Encoded X.509 Certificates (C509 Certificates)", Work in Progress, Internet-Draft, draft-ietf-cose-cbor-encoded-cert-11, , <https://datatracker.ietf.org/doc/html/draft-ietf-cose-cbor-encoded-cert-11>.
[CTA2063A]
ANSI/CTA, "ANSI/CTA 2063-A Small Unmanned Aerial Systems Numbers", , <https://shop.cta.tech/products/small-unmanned-aerial-systems-serial-numbers>.
[drip-registration-cwt]
Wiethuechter, A., "DRIP Entity Tag (DET) Registration using CoAP & CWTs", Work in Progress, Internet-Draft, draft-wiethuechter-drip-det-registration-coap-cwt-00, , <https://datatracker.ietf.org/doc/html/draft-wiethuechter-drip-det-registration-coap-cwt-00>.
[drip-registries]
Wiethuechter, A. and J. Reid, "DRIP Entity Tags (DET) in the Domain Name System (DNS)", Work in Progress, Internet-Draft, draft-ietf-drip-registries-19, , <https://datatracker.ietf.org/doc/html/draft-ietf-drip-registries-19>.
[drip_scripts]
"Python scripts to generate DETs and Endorsements", , <https://github.com/ietf-wg-drip/drip-scripts>.
[IEEE 802.1AR]
IEEE, "IEEE Standard for Local and Metropolitan Area Networks - Secure Device Identity", DOI 10.1109/ieeestd.2018.8423794, , <https://doi.org/10.1109/ieeestd.2018.8423794>.
[IPv6-SPECIAL]
IANA, "IANA IPv6 Special-Purpose Address Registry", <https://www.iana.org/assignments/iana-ipv6-special-registry/>.
[RFC4108]
Housley, R., "Using Cryptographic Message Syntax (CMS) to Protect Firmware Packages", RFC 4108, DOI 10.17487/RFC4108, , <https://www.rfc-editor.org/info/rfc4108>.
[RFC5280]
Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, , <https://www.rfc-editor.org/info/rfc5280>.
[RFC9153]
Card, S., Ed., Wiethuechter, A., Moskowitz, R., and A. Gurtov, "Drone Remote Identification Protocol (DRIP) Requirements and Terminology", RFC 9153, DOI 10.17487/RFC9153, , <https://www.rfc-editor.org/info/rfc9153>.
[RFC9374]
Moskowitz, R., Card, S., Wiethuechter, A., and A. Gurtov, "DRIP Entity Tag (DET) for Unmanned Aircraft System Remote ID (UAS RID)", RFC 9374, DOI 10.17487/RFC9374, , <https://www.rfc-editor.org/info/rfc9374>.
[RFC9434]
Card, S., Wiethuechter, A., Moskowitz, R., Zhao, S., Ed., and A. Gurtov, "Drone Remote Identification Protocol (DRIP) Architecture", RFC 9434, DOI 10.17487/RFC9434, , <https://www.rfc-editor.org/info/rfc9434>.

Appendix A. Test DETs and Endorsements

The following are test DETs and Endorsements for the test DKI. This testing environment is open to all. There are 4 RAAs available for others to build out. HDAs under the 4 preset RAAs, or under any of the 4, built out by others, are available. Finally the test HDA is available for setting up a handful of entities. Any tester wanting more than a few DETs for entities should plan on doing that under their own HDA.

The following are the test values and objects. They were generated using the csr-gen.py, raa-endorse.py, and hda-endorse.py scripts available at [drip_scripts].

Note, that as there is no APEX level at this time, the RAA Endorsement is self-signed.


raa16376
    Authorizing DET  (HID=16376|0)

# SN is there just because script needs it.
python csr-gen.py --keyname=raa16376 --serialnumber=0 --raa=16376/
 --hda=0
python raa-endorse.py --commandfile=raa16376

    HI: 32528c1c115d004d1f008d07ac507a2d83bbab746040522ea6cdc786fa
        bc8057
    DET: 2001003ffe00000506ab58754f68e6b3
    DET: 2001:003f:fe00:0005:06ab:5875:4f68:e6b3
    vnb="09/01/2024"
    vna="08/31/2026"
    Endorsement(136 bytes): 66d3e6c06a94fc402001003ffe00000506ab58
    754f68e6b332528c1c115d004d1f008d07ac507a2d83bbab746040522ea6cd
    c786fabc80572001003ffe00000506ab58754f68e6b3f5d13f1074171192f8
    f5e4b25f200cf3cc5ef6a8cc10d0c93e91ab882a888ccd7fb970c56c20e97e
    22f60b7d1179d214a7c9fa8c70081c3482667add575d0a08



hda16376-16376
    Authorizing DET  (HID=16376|16376)
# SN is there just because script needs it.
python csr-gen.py --keyname=hda16376-16376A --serialnumber=0
python raa-endorse.py --commandfile=hda16376-16376A

    HI: 4293a3ec0639737e65db3979fb3dab83a97510cfb52e83d5ecaea40adf
        45585d
    DET: 2001003ffe3ff805ce4d71fcd8a27a9d
    DET: 2001:003f:fe3f:f805:ce4d:71fc:d8a2:7a9d
    DETofRAA=2001003ffe00000506ab58754f68e6b3
    vnb="09/15/2024"
    vna="07/01/2026"

    Endorsement(136 bytes): 66e65bc06a4490c02001003ffe3ff805ce4d71
    fcd8a27a9d4293a3ec0639737e65db3979fb3dab83a97510cfb52e83d5ecae
    a40adf45585d2001003ffe00000506ab58754f68e6b3a96328ac620f9dd7d1
    2a7d9f6e94424b69e59584116d73763145be04ef743bbada14d11f158ee32e
    ff33296fb8cc6cad8d3cdfee866e27a720b685c731edde07


    Issuing DET  (HID=16376|16376)

# SN is there just because script needs it.
python csr-gen.py --keyname=hda16376-16376I --serialnumber=0
python raa-endorse.py --commandfile=hda16376-16376I

    HI: 95f4a64fc559a17092c738f7be02a9ed7aef51b152e4eb2c8b0a0dc175
        80b7e0
    DET: 2001003ffe3ff8059f5514beac58f8db
    DET: 2001:003f:fe3f:f805:9f55:14be:ac58:f8db
    DETofHDA=0x2001003ffe3ff805ce4d71fcd8a27a9d
    vnb="09/15/2024"
    vna="07/01/2026"

    Endorsement(136 bytes): 66e65bc06a4490c02001003ffe3ff8059f5514
    beac58f8db95f4a64fc559a17092c738f7be02a9ed7aef51b152e4eb2c8b0a
    0dc17580b7e02001003ffe3ff805ce4d71fcd8a27a9dea50c3de79536ea208
    fe792a3e7241d0d8c67fc8a94ec925709a3b19e8b7eaa4c1714762f4c83ea2
    0e10c4dc5ea049b22a51cfbbae39be5874c31fd5bf9e4f00


    UA DET in 16376.16376

python csr-gen.py --keyname=ua1-16376-16376/
 --serialnumber=x1224AABBCCDDEE56789
python hda-endorse.py --commandfile=ua1-16376-16376

    DET: 2001003ffe3ff80578cc488c41b52b28
    DET: 2001:003f:fe3f:f805:78cc:488c:41b5:2b28
    SN:  x1224AABBCCDDEE56789
    DETofHDA=0x2001003ffe3ff8059f5514beac58f8db
    vnb="09/19/2024"
    vna="09/20/2025"
    Endorsement(136 bytes): 66eba1c068ce26c02001003ffe3ff80578cc48
    8c41b52b2888f5e2d5c7161b5b15a590b4a56c4759fe46cb1bbad11f070eb3
    ec7bdd28a9692001003ffe3ff8059f5514beac58f8db861d2e2a41193aac09
    8d96c6e23611733cfbbace751e66f3c1e525e0864fa249e2dc3e48e3477256
    770d02dfb0d83ec29ae7887851c2031c907a90f966b05d0d

Figure 4: Test DKI DETs and Endorsements

A.1. Test DNS

The DNS tree(s) for the above test data is still in limbo and will be added in a later version of this draft with the proposed DET RR from [drip-registries].

Appendix B. Test X.509 certificates

B.1. Test Lite X.509 certificates

The following the test DRIP X.509 certificates that mirror the test Endorsements.


  raa16376.pem (der is 334 bytes)

-----BEGIN CERTIFICATE-----
MIIBSjCB/aADAgECAhR3h9ip63LkGZCv25TKeVSCy5PSxTAFBgMrZXAwKzEpMCcG
A1UEAwwgMjAwMTAwM2ZmZTAwMDAwNTA2YWI1ODc1NGY2OGU2YjMwHhcNMjQwOTAx
MDAwMTAwWhcNMjYwODMxMjM1OTAwWjAbMRkwFwYDVQQDDBBEUklQLVJBQS1BLTE2
Mzc2MCowBQYDK2VwAyEAMlKMHBFdAE0fAI0HrFB6LYO7q3RgQFIups3Hhvq8gFej
QzBBMB4GA1UdEQEB/wQUMBKHECABAD/+AAAFBqtYdU9o5rMwDwYDVR0TAQH/BAUw
AwEB/zAOBgNVHQ8BAf8EBAMCAgQwBQYDK2VwA0EA7+m7dHX/Mv9yLszLuWfBa2kO
mQCEhxyu4yPKaRPEdzzTGsbq8ECF+CGDBiWwt2jiOIK52x6TGtvUbmBpmfbhDw==
-----END CERTIFICATE-----

Certificate: 509 bytes
    Data:
        Version: 3 (0x2)
        Serial Number:
          77:87:d8:a9:eb:72:e4:19:90:af:db:94:ca:79:54:82:cb:93:d2:c5
        Signature Algorithm: ED25519
        Issuer: CN = 2001003ffe00000506ab58754f68e6b3
        Validity
            Not Before: Sep  1 00:01:00 2024 GMT
            Not After : Aug 31 23:59:00 2026 GMT
        Subject: CN = DRIP-RAA-A-16376
        Subject Public Key Info:
            Public Key Algorithm: ED25519
                ED25519 Public-Key:
                pub:
                    32:52:8c:1c:11:5d:00:4d:1f:00:8d:07:ac:50:7a:
                    2d:83:bb:ab:74:60:40:52:2e:a6:cd:c7:86:fa:bc:
                    80:57
        X509v3 extensions:
            X509v3 Subject Alternative Name: critical
                IP Address:2001:3F:FE00:5:6AB:5875:4F68:E6B3
            X509v3 Basic Constraints: critical
                CA:TRUE
            X509v3 Key Usage: critical
                Certificate Sign
    Signature Algorithm: ED25519
    Signature Value:
        ef:e9:bb:74:75:ff:32:ff:72:2e:cc:cb:b9:67:c1:6b:69:0e:
        99:00:84:87:1c:ae:e3:23:ca:69:13:c4:77:3c:d3:1a:c6:ea:
        f0:40:85:f8:21:83:06:25:b0:b7:68:e2:38:82:b9:db:1e:93:
        1a:db:d4:6e:60:69:99:f6:e1:0f


  Authentication hda16376-16376.pem (der is 341 bytes)

-----BEGIN CERTIFICATE-----
MIIBUTCCAQOgAwIBAgIUWffmfHh1wD4kx1sh/voUrCHqYEQwBQYDK2VwMCsxKTAn
BgNVBAMMIDIwMDEwMDNmZmUwMDAwMDUwNmFiNTg3NTRmNjhlNmIzMB4XDTI0MDkx
NTAwMDEwMFoXDTI2MDcwMTIzNTkwMFowITEfMB0GA1UEAwwWRFJJUC1IREEtQS0x
NjM3Ni0xNjM3NjAqMAUGAytlcAMhAEKTo+wGOXN+Zds5efs9q4OpdRDPtS6D1eyu
pArfRVhdo0MwQTAeBgNVHREBAf8EFDAShxAgAQA//j/4Bc5NcfzYonqdMA8GA1Ud
EwEB/wQFMAMBAf8wDgYDVR0PAQH/BAQDAgIEMAUGAytlcANBACHQ+i1C56CwyE6d
rjq7Ogrez4vfylAXgB6xSTXl7Uh85TI9B+jUl3BJPlvFJS5KXXw4mc1Fa3L7hIGd
zSQWPQc=
-----END CERTIFICATE-----

Certificate:   518 bytes
    Data:
        Version: 3 (0x2)
        Serial Number:
          59:f7:e6:7c:78:75:c0:3e:24:c7:5b:21:fe:fa:14:ac:21:ea:60:44
        Signature Algorithm: ED25519
        Issuer: CN = 2001003ffe00000506ab58754f68e6b3
        Validity
            Not Before: Sep 15 00:01:00 2024 GMT
            Not After : Jul  1 23:59:00 2026 GMT
        Subject: CN = DRIP-HDA-A-16376-16376
        Subject Public Key Info:
            Public Key Algorithm: ED25519
                ED25519 Public-Key:
                pub:
                    42:93:a3:ec:06:39:73:7e:65:db:39:79:fb:3d:ab:
                    83:a9:75:10:cf:b5:2e:83:d5:ec:ae:a4:0a:df:45:
                    58:5d
        X509v3 extensions:
            X509v3 Subject Alternative Name: critical
                IP Address:2001:3F:FE3F:F805:CE4D:71FC:D8A2:7A9D
            X509v3 Basic Constraints: critical
                CA:TRUE
            X509v3 Key Usage: critical
                Certificate Sign
    Signature Algorithm: ED25519
    Signature Value:
        21:d0:fa:2d:42:e7:a0:b0:c8:4e:9d:ae:3a:bb:3a:0a:de:cf:
        8b:df:ca:50:17:80:1e:b1:49:35:e5:ed:48:7c:e5:32:3d:07:
        e8:d4:97:70:49:3e:5b:c5:25:2e:4a:5d:7c:38:99:cd:45:6b:
        72:fb:84:81:9d:cd:24:16:3d:07


  Issuing hda16376-16376.pem (der is 341 bytes)

-----BEGIN CERTIFICATE-----
MIIBUTCCAQOgAwIBAgIURlST/Y7ug5+XOsyX0nxxMubKnmkwBQYDK2VwMCsxKTAn
BgNVBAMMIDIwMDEwMDNmZmUzZmY4MDVjZTRkNzFmY2Q4YTI3YTlkMB4XDTI0MDkx
NTAwMDEwMFoXDTI2MDcwMTIzNTkwMFowITEfMB0GA1UEAwwWRFJJUC1IREEtSS0x
NjM3Ni0xNjM3NjAqMAUGAytlcAMhAJX0pk/FWaFwksc4974Cqe1671GxUuTrLIsK
DcF1gLfgo0MwQTAeBgNVHREBAf8EFDAShxAgAQA//j/4BZ9VFL6sWPjbMA8GA1Ud
EwEB/wQFMAMBAf8wDgYDVR0PAQH/BAQDAgIEMAUGAytlcANBANXZXfdkuaUGbHzS
To8zHiNLL/EVBJYfX65JafReppAEDdcu22nHykZpLJS+gVv4BHY8fI+MwsFqkXn5
iWr3PQE=
-----END CERTIFICATE-----

Certificate:    518 bytes
    Data:
        Version: 3 (0x2)
        Serial Number:
          46:54:93:fd:8e:ee:83:9f:97:3a:cc:97:d2:7c:71:32:e6:ca:9e:69
        Signature Algorithm: ED25519
        Issuer: CN = 2001003ffe3ff805ce4d71fcd8a27a9d
        Validity
            Not Before: Sep 15 00:01:00 2024 GMT
            Not After : Jul  1 23:59:00 2026 GMT
        Subject: CN = DRIP-HDA-I-16376-16376
        Subject Public Key Info:
            Public Key Algorithm: ED25519
                ED25519 Public-Key:
                pub:
                    95:f4:a6:4f:c5:59:a1:70:92:c7:38:f7:be:02:a9:
                    ed:7a:ef:51:b1:52:e4:eb:2c:8b:0a:0d:c1:75:80:
                    b7:e0
        X509v3 extensions:
            X509v3 Subject Alternative Name: critical
                IP Address:2001:3F:FE3F:F805:9F55:14BE:AC58:F8DB
            X509v3 Basic Constraints: critical
                CA:TRUE
            X509v3 Key Usage: critical
                Certificate Sign
    Signature Algorithm: ED25519
    Signature Value:
        d5:d9:5d:f7:64:b9:a5:06:6c:7c:d2:4e:8f:33:1e:23:4b:2f:
        f1:15:04:96:1f:5f:ae:49:69:f4:5e:a6:90:04:0d:d7:2e:db:
        69:c7:ca:46:69:2c:94:be:81:5b:f8:04:76:3c:7c:8f:8c:c2:
        c1:6a:91:79:f9:89:6a:f7:3d:01


  UA1-16376-16376 CSR

Certificate Request:
    Data:
        Version: 1 (0x0)
        Subject: serialNumber = x1224AABBCCDDEE56789
        Subject Public Key Info:
            Public Key Algorithm: ED25519
                ED25519 Public-Key:
                pub:
                    88:f5:e2:d5:c7:16:1b:5b:15:a5:90:b4:a5:6c:47:
                    59:fe:46:cb:1b:ba:d1:1f:07:0e:b3:ec:7b:dd:28:
                    a9:69
        Attributes:
            (none)
            Requested Extensions:
    Signature Algorithm: ED25519
    Signature Value:
        e1:18:e8:0f:78:ef:99:47:8f:ce:12:c7:f0:fa:48:eb:17:3b:
        7e:b8:0d:25:46:0e:ca:ff:bb:48:54:ea:d0:8b:52:89:9c:49:
        8a:4c:35:be:8f:b2:77:ff:9d:64:e4:1e:cf:23:12:5b:8b:24:
        e2:0f:ac:07:33:39:b9:10:eb:00

  UA1-16376-16376.pem (der is 255 bytes)

-----BEGIN CERTIFICATE-----
MIH8MIGvoAMCAQICAiIOMAUGAytlcDArMSkwJwYDVQQDDCAyMDAxMDAzZmZlM2Zm
ODA1OWY1NTE0YmVhYzU4ZjhkYjAeFw0yNDA5MTkwMDAxMDBaFw0yNTA5MjAyMzU5
MDBaMAAwKjAFBgMrZXADIQCI9eLVxxYbWxWlkLSlbEdZ/kbLG7rRHwcOs+x73Sip
aaMiMCAwHgYDVR0RAQH/BBQwEocQIAEAP/4/+AV4zEiMQbUrKDAFBgMrZXADQQB1
g4Yw/Rer9hISVLVUvad8dKJSe2giAaNOZbDtexeWhsZEXMWNWuhGkEefKk5IbAM9
cs9islWR1bX+o91HMXcB
-----END CERTIFICATE-----

Certificate:    400 bytes
    Data:
        Version: 3 (0x2)
        Serial Number: 8718 (0x220e)
        Signature Algorithm: ED25519
        Issuer: CN = 2001003ffe3ff8059f5514beac58f8db
        Validity
            Not Before: Sep 19 00:01:00 2024 GMT
            Not After : Sep 20 23:59:00 2025 GMT
        Subject:
        Subject Public Key Info:
            Public Key Algorithm: ED25519
                ED25519 Public-Key:
                pub:
                    88:f5:e2:d5:c7:16:1b:5b:15:a5:90:b4:a5:6c:47:
                    59:fe:46:cb:1b:ba:d1:1f:07:0e:b3:ec:7b:dd:28:
                    a9:69
        X509v3 extensions:
            X509v3 Subject Alternative Name: critical
                IP Address:2001:3F:FE3F:F805:78CC:488C:41B5:2B28
    Signature Algorithm: ED25519
    Signature Value:
        75:83:86:30:fd:17:ab:f6:12:12:54:b5:54:bd:a7:7c:74:a2:
        52:7b:68:22:01:a3:4e:65:b0:ed:7b:17:96:86:c6:44:5c:c5:
        8d:5a:e8:46:90:47:9f:2a:4e:48:6c:03:3d:72:cf:62:b2:55:
        91:d5:b5:fe:a3:dd:47:31:77:01

Figure 5: Test Lite X.509 certificates

B.2. Test Lite C509 certificates

The CBOR Encoded X.509 Certificates (C509 Certificates) [C509-Certificates] provides a standards-based approach to reduce the size of X.509 certificates both on-the-wire and in storage.

These C509 certificates MAY be stored in the DET RR, but are more likely to by used in over-the-air protocols and exist only for transmission, being converted from/to their source X.509 certificates.

Author's Note: This section is still a Work in Progress. The CBOR diagnostic tool is currently not working, and that content should be added back in on a later revision. Further note that we think there is a bug in the c509 code, making the certificate version = 1, not 3.

The following are examples of a C509 cert.


  raa16376.cert CBOR:

COSE_X509 (212 bytes)
8B 01 54 77 87 D8 A9 EB 72 E4 19 90 AF DB 94 CA 79 54 82 CB 93 D2 C5
78 20 32 30 30 31 30 30 33 66 66 65 30 30 30 30 30 35 30 36 61 62 35
38 37 35 34 66 36 38 65 36 62 33 1A 66 D3 AE BC 1A 6A 96 15 44 70 44
52 49 50 2D 52 41 41 2D 41 2D 31 36 33 37 36 0A 58 20 32 52 8C 1C 11
5D 00 4D 1F 00 8D 07 AC 50 7A 2D 83 BB AB 74 60 40 52 2E A6 CD C7 86
FA BC 80 57 86 22 82 07 50 20 01 00 3F FE 00 00 05 06 AB 58 75 4F 68
E6 B3 23 20 21 18 20 0C 58 40 EF E9 BB 74 75 FF 32 FF 72 2E CC CB B9
67 C1 6B 69 0E 99 00 84 87 1C AE E3 23 CA 69 13 C4 77 3C D3 1A C6 EA
F0 40 85 F8 21 83 06 25 B0 B7 68 E2 38 82 B9 DB 1E 93 1A DB D4 6E 60
69 99 F6 E1 0F


  ua1-16376-16376.cert CBOR:

COSE_X509 (173 bytes)
8B 01 42 22 0E 78 20 32 30 30 31 30 30 33 66 66 65 33 66 66 38 30 35
39 66 35 35 31 34 62 65 61 63 35 38 66 38 64 62 1A 66 EB 69 BC 1A 68
CF 3F C4 80 0A 58 20 88 F5 E2 D5 C7 16 1B 5B 15 A5 90 B4 A5 6C 47 59
FE 46 CB 1B BA D1 1F 07 0E B3 EC 7B DD 28 A9 69 82 22 82 07 50 20 01
00 3F FE 3F F8 05 78 CC 48 8C 41 B5 2B 28 0C 58 40 75 83 86 30 FD 17
AB F6 12 12 54 B5 54 BD A7 7C 74 A2 52 7B 68 22 01 A3 4E 65 B0 ED 7B
17 96 86 C6 44 5C C5 8D 5A E8 46 90 47 9F 2A 4E 48 6C 03 3D 72 CF 62
B2 55 91 D5 B5 FE A3 DD 47 31 77 01

Figure 6: Test Lite C.509 certificates

Acknowledgments

Many people assisted in creating the python scripts for making DETs and DRIP Endorsements. Any roughness in the scripts is all my doing.

The openssl-user mailing list provided needed help in getting openssl command line to do what was needed to build the test PKI.

The COSE C509 authors are providing active help in creating the C509 equivalent objects.

Authors' Addresses

Robert Moskowitz
HTT Consulting
Oak Park, MI 48237
United States of America
Stuart W. Card
AX Enterprize, LLC
4947 Commercial Drive
Yorkville, NY 13495
United States of America