Internet-Draft | EDHOC Application Profiles | October 2024 |
Tiloca & Höglund | Expires 24 April 2025 | [Page] |
- Workgroup:
- LAKE Working Group
- Internet-Draft:
- draft-tiloca-lake-app-profiles-03
- Published:
- Intended Status:
- Standards Track
- Expires:
Coordinating the Use of Application Profiles for Ephemeral Diffie-Hellman Over COSE (EDHOC)
Abstract
The lightweight authenticated key exchange protocol Ephemeral Diffie-Hellman Over COSE (EDHOC) requires certain parameters to be agreed out-of-band, in order to ensure its successful completion. To this end, application profiles specify the intended use of EDHOC to allow for the relevant processing and verifications to be made. This document defines a number of means to coordinate the use and discovery of EDHOC application profiles. Also, it defines a canonical, CBOR-based representation that can be used to describe, distribute, and store EDHOC application profiles. Finally, this document defines a set of well-known EDHOC application profiles.¶
Discussion Venues
This note is to be removed before publishing as an RFC.¶
Discussion of this document takes place on the Lightweight Authenticated Key Exchange Working Group mailing list (lake@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/lake/.¶
Source for this draft and an issue tracker can be found at https://gitlab.com/crimson84/draft-tiloca-lake-app-profiles.¶
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/.¶
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This Internet-Draft will expire on 24 April 2025.¶
Copyright Notice
Copyright (c) 2024 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
1. Introduction
Ephemeral Diffie-Hellman Over COSE (EDHOC) [RFC9528] is a lightweight authenticated key exchange protocol, especially intended for use in constrained scenarios.¶
In order to successfully run EDHOC, the two peers acting as Initiator and Responder have to agree on certain parameters. Some of those are in-band and communicated through the protocol execution, during which a few of them may even be negotiated. However, other parameters have to be known out-of-band, before running the EDHOC protocol.¶
As discussed in Section 3.9 of [RFC9528], applications can use EDHOC application profiles, which specify the intended usage of EDHOC to allow for the relevant processing and verifications to be made. In particular, an EDHOC application profile may include both in-band and out-of-band parameters.¶
This document defines a number of means to coordinate the use and discovery of EDHOC application profiles, that is:¶
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The new IANA registry "EDHOC Application Profiles" defined in Section 11.5, where to register integer identifiers of EDHOC application profiles to use as corresponding Profile IDs.¶
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The new parameter "ed-prof" defined in Section 2.1. This parameter is employed to specify an EDHOC application profile identified by its Profile ID, and can be used as target attribute in a web link [RFC8288] to an EDHOC resource, or as filter criteria in a discovery request to discover EDHOC resources.¶
For instance, the target attribute can be used in a link-format document [RFC6690] describing EDHOC resources at a server, when EDHOC is transferred over CoAP [RFC7252] (see Appendix A.2 of [RFC9528] as well as [I-D.ietf-core-oscore-edhoc]).¶
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The new parameter "app_prof" defined in Section 2.2 for the EDHOC_Information object specified in [I-D.ietf-ace-edhoc-oscore-profile]. This parameter is employed to specify a set of EDHOC application profiles, each identified by its Profile ID.¶
For instance, the parameter can be used in the EDHOC and OSCORE profile [I-D.ietf-ace-edhoc-oscore-profile] of the ACE framework for authentication and authorization in constrained environments (ACE) [RFC9200], in order to indicate the EDHOC application profiles supported by an ACE resource server.¶
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Additional parameters that provide information about an EDHOC application profile. A subset of these parameters are to be used as target attributes in a web link to an EDHOC resource, or as filter criteria in a discovery request to discover EDHOC resources (see Section 3). Another subset of these parameters are to be used as elements of the EDHOC_Information object (see Section 4).¶
In order to ensure the applicability of such parameters beyond transport- or setup-specific scenarios, this document also defines a canonical, CBOR-based representation that can be used to describe, distribute, and store EDHOC application profiles as CBOR data items (see Section 5). The defined representation is transport- and setup-independent, and avoids the need to reinvent an encoding for the available options to run the EDHOC protocol or the selection logic to apply on those.¶
The CBOR-based representation of an EDHOC application profile can be, for example: retrieved as a result of a discovery process; or retrieved/provided during the retrieval/provisioning of an EDHOC peer's public authentication credential; or obtained during the execution of a device on-boarding/registration workflow.¶
Finally, this document defines a set of well-known EDHOC application profiles (see Section 6). These application profiles are meant to reflect what is most common and expected to be supported by EDHOC peers, while they are not to be intended as "default" application profiles or as a deviation from what is mandatory to support for EDHOC peers (see Section 8 of [RFC9528]).¶
1.1. 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.¶
The reader is expected to be familiar with terms and concepts defined in EDHOC [RFC9528], and with the use of EDHOC with CoAP [RFC7252] and OSCORE [RFC8613] defined in [I-D.ietf-core-oscore-edhoc].¶
Concise Binary Object Representation (CBOR) [RFC8949] and Concise Data Definition Language (CDDL) [RFC8610] are used in this document. CDDL predefined type names, especially bstr for CBOR byte strings and tstr for CBOR text strings, are used extensively in this document.¶
CBOR data items are represented using the CBOR extended diagnostic notation as defined in Section 8 of [RFC8949] and Appendix G of [RFC8610] ("diagnostic notation"). Diagnostic notation comments are used to provide a textual representation of the parameters' keys and values.¶
In the CBOR diagnostic notation used in this document, constructs of the form e'SOME_NAME' are replaced by the value assigned to SOME_NAME in the CDDL model shown in Figure 2 of Appendix A. For example, {e'methods' : [0, 1, 2, 3], e'cipher_suites': 3} stands for {1 : [0, 1, 2, 3], 2 : 3}.¶
Note to RFC Editor: Please delete the paragraph immediately preceding this note. Also, in the CBOR diagnostic notation used in this document, please replace the constructs of the form e'SOME_NAME' with the value assigned to SOME_NAME in the CDDL model shown in Figure 2 of Appendix A. Finally, please delete this note.¶
2. Identifying EDHOC Application Profiles by Profile ID
This section defines two means to identify EDHOC application profiles by their Profile IDs, i.e., the parameter "ed-prof" for web linking (see Section 2.1) and the parameter "app_prof" of the EDHOC_Information object (see Section 2.2).¶
2.1. Web Linking
Section 6 of [I-D.ietf-core-oscore-edhoc] defines a number of target attributes that can be used in a web link [RFC8288] with resource type "core.edhoc" (see Section 10.10 of [RFC9528]). This is the case, e.g., when using a link-format document [RFC6690] describing EDHOC resources at a server, when EDHOC is transferred over CoAP [RFC7252] as defined in Appendix A.2 of [RFC9528]. This allows a client to obtain relevant information about the EDHOC application profile(s) to be used with a certain EDHOC resource.¶
In the same spirit, this section defines the following additional parameter, which can be optionally specified as a target attribute with the same name in the link to the respective EDHOC resource, or among the filter criteria in a discovery request from a client.¶
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'ed-prof', specifying an EDHOC application profile supported by the server. This parameter MUST specify a single value, which is taken from the 'Profile ID' column of the "EDHOC Application Profiles" registry defined in Section 11.5 of this document. This parameter MAY occur multiple times, with each occurrence specifying an EDHOC application profile.¶
When specifying the parameter 'ed-prof' in a link to an EDHOC resource, the target attribute rt="core.edhoc" MUST be included.¶
If a link to an EDHOC resource includes occurrences of the target attribute 'ed-prof', then the following applies.¶
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The link MUST NOT include other target attributes that provide information about an EDHOC application profile (see, e.g., Section 6 of [I-D.ietf-core-oscore-edhoc] and Section 3 of this document), with the exception of the target attribute 'ed-ead' that MAY be included.¶
The recipient MUST ignore other target attributes that provide information about an EDHOC application profile, with the exception of the target attribute 'ed-ead'.¶
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If the link includes occurrences of the target attribute 'ed-ead', the link provides the following information: when using the target EDHOC resource as per the EDHOC application profile indicated by any occurrence of the target attribute 'ed-prof', the server supports the EAD items that are specified in the definition of that EDHOC application profile, as well as the EAD items indicated by the occurrences of the target attribute 'ed-ead'.¶
The example in Figure 1 shows how a CoAP client discovers two EDHOC resources at a CoAP server, and obtains information about the application profile corresponding to each of those resources. The Link Format notation from Section 5 of [RFC6690] is used.¶
The example assumes the existence of an EDHOC application profile identified by the integer Profile ID 500, which is supported by the EDHOC resource at /edhoc-alt and whose definition includes the support for the EAD items with EAD label 111 and 222.¶
Therefore, the link to the EDHOC resource at /edhoc-alt indicates that, when using that EDHOC resource as per the EDHOC application profile with Profile ID 500, the server supports the EAD items with EAD label 111, 222, and 333.¶
2.2. EDHOC_Information Object
Section 3.4 of [I-D.ietf-ace-edhoc-oscore-profile] defines the EDHOC_Information object, as including information that guides two peers towards executing the EDHOC protocol, and defines an initial set of its parameters.¶
This document defines the new parameter "app_prof" of the EDHOC_Information object, as summarized in Table 1 and described further below.¶
Name | CBOR label | CBOR type | Registry | Description |
---|---|---|---|---|
app_prof | 18 | int or array | EDHOC Application Profiles Registry | Set of supported EDHOC Application Profiles |
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app_prof: This parameter specifies a set of supported EDHOC application profiles, identified by their Profile ID. If the set is composed of a single EDHOC application profile, its Profile ID is encoded as an integer. Otherwise, the set is encoded as an array of integers, where each array element encodes one Profile ID. In JSON, the "app_prof" value is an integer or an array of integers. In CBOR, "app_prof" is an integer or an array of integers, and has label 18. The integer values are taken from the 'Profile ID' column of the "EDHOC Application Profiles" registry defined in Section 11.5 of this document.¶
2.2.1. Use in the EDHOC and OSCORE Profile of the ACE Framework
Section 3 of [I-D.ietf-ace-edhoc-oscore-profile] defines how the EDHOC_Information object can be used within the workflow of the EDHOC and OSCORE transport profile of the ACE framework for authentication and authorization in constrained environments (ACE) [RFC9200].¶
In particular, the AS-to-C Access Token Response includes the parameter "edhoc_info", with value an EDHOC_Information object. This allows the ACE authorization server (AS) to provide the ACE client (C) with information about how to run the EDHOC protocol with the ACE resource server (RS) for which the access token is issued.¶
Similarly, the access token includes the corresponding claim "edhoc_info", with value an EDHOC_Information object. This allows the AS to provide the ACE RS with information about how to run the EDHOC protocol with the ACE client, according to the issued access token.¶
In turn, the EDHOC_Information object can include the parameter "app_prof" defined in this document. This parameter indicates a set of EDHOC application profiles associated with the EDHOC resource to use at the RS, which is either implied or specified by the parameter "uri_path" within the same EDHOC_Information object.¶
If the EDHOC_Information object specified as value of "edhoc_info" includes the "app_prof" parameter, then the following applies.¶
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The object MUST NOT include other parameters that provide information pertaining to an EDHOC application profile, with the exception of the parameter "eads" that MAY be included.¶
C and RS MUST ignore other parameters present in the EDHOC_Information object, with the exception of the parameter "eads".¶
At the time of writing this document, such parameters are: "methods", "cipher_suites", "message_4", "comb_req", "osc_ms_len", "osc_salt_len", "osc_version", "cred_types", "id_cred_types", "initiator", and "responder" (which are all defined in Section 3.4 of [I-D.ietf-ace-edhoc-oscore-profile]), as well as those defined in Section 4 of this document.¶
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If the EDHOC_Information object specified in the parameter "edhoc_info" of the AS-to-C Access Token Response includes the parameter "eads", the object provides the following information.¶
When using the target EDHOC resource as per any EDHOC application profile indicated by the parameter "app_prof", the ACE RS for which the access token is issued supports the EAD items that are specified in the definition of that EDHOC application profile, as well as the EAD items indicated by the parameter "eads".¶
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If the EDHOC_Information object specified in the claim "edhoc_info" of the access token includes the parameter "eads", the object provides the following information.¶
When using the target EDHOC resource as per any EDHOC application profile indicated by the parameter "app_prof", the ACE client to which the access token is issued supports the EAD items that are specified in the definition of that EDHOC application profile, as well as the EAD items indicated by the parameter "eads".¶
3. Additional Parameters for Web Linking
Building on what is defined and prescribed in Section 6 of [I-D.ietf-core-oscore-edhoc], this section defines additional parameters for web linking [RFC8288], which can be used to obtain relevant pieces of information from the EDHOC application profile associated with an EDHOC resource.¶
These parameters can be optionally specified as target attributes with the same name in a link with resource type "core.edhoc" (see Section 10.10 of [RFC9528]) targeting an EDHOC resource, or as filter criteria in a discovery request from a client.¶
When specifying any of the parameters defined below in a link to an EDHOC resource, the target attribute rt="core.edhoc" MUST be included.¶
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'ed-max-msgsize', specifying the admitted maximum size of EDHOC messages in bytes. This parameter MUST specify a single unsigned integer value.¶
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'ed-coap-cf', specifying that CoAP messages have to include the CoAP Content-Format Option with value 64 (application/edhoc+cbor-seq) or 65 (application/cid-edhoc+cbor-seq) as appropriate, when the message payload includes exclusively an EDHOC message possibly prepended by an EDHOC connection identifier (see Sections 3.4.1 and A.2 of [RFC9528]). A value MUST NOT be given to this parameter and any present value MUST be ignored by the recipient.¶
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'ed-idep-t', specifying a type of endpoint identity for EDHOC supported by the server. This parameter MUST specify a single value, which is taken from the 'CBOR Label' column of the "EDHOC Endpoint Identity Types" Registry defined in Section 8 of this document. This parameter MAY occur multiple times, with each occurrence specifying a type of endpoint identity for EDHOC.¶
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'ed-tp', specifying a means for transporting EDHOC messages supported by the server. This parameter MUST specify a single value, which is taken from the 'Transport ID' column of the "EDHOC Transports" Registry defined in Section 9 of this document. This parameter MAY occur multiple times, with each occurrence specifying a means for transporting EDHOC messages.¶
4. Additional Parameters of the EDHOC_Information Object
This section defines additional parameters of the EDHOC_Information object defined in Section 3.4 of [I-D.ietf-ace-edhoc-oscore-profile]. These parameters are summarized in Table 2 and described further below.¶
Editor's note: these parameters can better be defined directly in Section 3.4 of [I-D.ietf-ace-edhoc-oscore-profile].¶
Name | CBOR label | CBOR type | Registry | Description |
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max_msgsize | 14 | uint | Maximum size of EDHOC messages in bytes | |
coap_cf | 15 | True of False | Requested use of the CoAP Content-Format Option in CoAP messages whose payload includes exclusively an EDHOC message, possibly prepended by an EDHOC connection identifier | |
id_ep_types | 16 | int or array | EDHOC Endpoint Identity Types Registry | Set of supported types of endpoint identities for EDHOC |
transports | 17 | int or array | EDHOC Transports Registry | Set of supported means for transporting EDHOC messages |
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max_msgsize: This parameter specifies the admitted maximum size of EDHOC messages in bytes. In JSON, the "max_msgsize" value is an unsigned integer. In CBOR, "max_msgsize" is an unsigned integer and has label 14.¶
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coap_cf: This parameter specifies whether it is required that CoAP messages include the CoAP Content-Format Option with value 64 (application/edhoc+cbor-seq) or 65 (application/cid-edhoc+cbor-seq) as appropriate, when the message payload includes exclusively an EDHOC message possibly prepended by an EDHOC connection identifier (see Sections 3.4.1 and A.2 of [RFC9528]). In JSON, the "coap_cf" value is a boolean. In CBOR, "coap_cf" is the simple value
true
(0xf5) orfalse
(0xf4), and has label 15.¶ -
id_ep_types: This parameter specifies a set of supported types of endpoint identities for EDHOC. If the set is composed of a single type of endpoint identity, this is encoded as an integer. Otherwise, the set is encoded as an array, where each array element encodes one type of endpoint identity as an integer. In JSON, the "id_ep_types" value is an integer or an array of integers. In CBOR, "id_ep_types" is an integer or an array of integers, and has label 16. The integer values are taken from the 'CBOR Label' column of the "EDHOC Endpoint Identity Types" registry defined in Section 11.6 of this document.¶
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transports: This parameter specifies a set of supported means for transporting EDHOC messages. If the set is composed of a single means for transporting EDHOC messages, this is encoded as an integer. Otherwise, the set is encoded as an array, where each array element encodes one means for transporting EDHOC messages as an integer. In JSON, the "transports" value is an integer or an array of integers. In CBOR, "transports" is an integer or an array of integers, and has label 17. The integer values are taken from the 'Transport ID' column of the "EDHOC Transports" Registry defined in Section 9 of this document.¶
5. Representation of an EDHOC Application Profile
This section defines the EDHOC_Application_Profile object, which can be used as a canonical representation of EDHOC application profiles for their description, distribution, and storage.¶
An EDHOC_Application_Profile object is encoded as a CBOR map [RFC8949]. Each element of the CBOR map is an element of the CBOR-encoded EDHOC_Information object defined in Section 3.4 of [I-D.ietf-ace-edhoc-oscore-profile], and thus uses the corresponding CBOR abbreviations from the 'CBOR label' column of the "EDHOC Information" registry defined in [I-D.ietf-ace-edhoc-oscore-profile].¶
The CBOR map encoding an EDHOC_Application_Profile object MUST include the element "app_prof" defined in this document. The value of the element "app_prof" is the unique identifier of the EDHOC application profile described by the EDHOC_Application_Profile object, taken from the 'Profile ID' column of the "EDHOC Application Profiles" registry defined in this document, and encoded as a CBOR integer.¶
The CBOR map MUST include the following elements defined for the EDHOC_Information object: "methods" and "cred_types".¶
The CBOR map MUST NOT include the following elements defined for the EDHOC_Information object: "session_id", "uri_path", "initiator", and "responder".¶
The CBOR map MAY include other elements defined for the EDHOC_Information object. These also comprise the new parameters defined in Section 4 of this document.¶
Furthermore, consistent with Sections 8 and A.1 of [RFC9528] and with Section 5.4 of [RFC8613], the following applies:¶
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If the element "cipher_suites" is not present in the CBOR map, this indicates that the EDHOC application profile uses the EDHOC cipher suites 2 and 3.¶
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If the element "id_cred_types" is not present in the CBOR map, this indicates that the EDHOC application profile uses "kid" as type of authentication credential identifiers for EDHOC.¶
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If the element "osc_ms_len" is not present in the CBOR map, this indicates that, when using EDHOC to key OSCORE [RFC8613], the size of the OSCORE Master Secret in bytes is equal to the size of the key length for the application AEAD Algorithm of the selected cipher suite for the EDHOC session.¶
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If the element "osc_salt_len" is not present in the CBOR map, this indicates that, when using EDHOC to key OSCORE, the size of the OSCORE Master Salt in bytes is 8.¶
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If the element "osc_version" is not present in the CBOR map, this indicates that, when using EDHOC to key OSCORE, the OSCORE Version Number has value 1.¶
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The absence of any other elements in the CBOR map MUST NOT result in assuming any value.¶
If an element is present in the CBOR map and the information that it specifies is intrinsically a set of one or more co-existing alternatives, then all the specified alternatives apply for the EDHOC application profile in question.¶
For example, the element "cipher_suites" with value the CBOR array [0, 2] means that, in order to adhere to the EDHOC application profile in question, an EDHOC peer has to implement both the EDHOC cipher suites 0 and 2, because either of them can be used by another EDHOC peer also adhering to the same EDHOC application profile.¶
The CDDL grammar describing the EDHOC_Application_Profile object is:¶
EDHOC_Application_Profile = { 1 => int / array, ; methods 9 => int / array, ; cred_types 18 => int, ; app_prof * int / tstr => any }¶
6. Well-known EDHOC Application Profiles
This section defines a set of well-known EDHOC application profiles that are meant to reflect what is most common and expected to be supported by EDHOC peers.¶
The well-known application profiles are not to be intended as "default" profiles to use, in case no other indication is provided to EDHOC peers.¶
In particular, an EDHOC peer MUST NOT assume that, unless otherwise indicated, any of such profiles is used when running EDHOC through a well-known EDHOC resource, such as the resource at /.well-known/edhoc when EDHOC messages are transported as payload of CoAP messages (see Appendix A.2 of [RFC9528]).¶
Building on the above, the well-known application profiles are not intended to deviate from what is mandatory to support for EDHOC peers, which is defined by the compliance requirements in Section 8 of [RFC9528].¶
The rest of this section defines the well-known application profiles, each of which is represented by means of an EDHOC_Application_Profile object (see Section 5) using the CBOR extended diagnostic notation.¶
An entry for each well-known application profile is also registered at the "EDHOC Application Profiles" registry defined in Section 11.5 of this document.¶
6.1. Well-Known Application Profile WK-MINIMAL_CS_2
{ e'methods' : 3, / EDHOC Method Type 3 / e'cipher_suites' : 2, / EDHOC Cipher Suite 2 / e'cred_types' : 1, / CWT Claims Set (CCS) / e'id_cred_types' : 4, / kid / e'app_prof' : e'APP-PROF-WK-MINIMAL-CS-2' }¶
This application profile is aligned with the example trace of EDHOC compiled in Section 3 of [RFC9529].¶
6.2. Well-Known Application Profile WK-MINIMAL_CS_0
{ e'methods' : 3, / EDHOC Method Type 3 / e'cipher_suites' : 0, / EDHOC Cipher Suite 0 / e'cred_types' : 1, / CWT Claims Set (CCS) / e'id_cred_types' : 4, / kid / e'app_prof' : e'APP-PROF-WK-MINIMAL-CS-0' }¶
6.3. Well-Known Application Profile WK-BASIC_CS_2_X509
{ e'methods' : [0, 3], / EDHOC Method Types 0 and 3 / e'cipher_suites' : 2, / EDHOC Cipher Suite 2 / e'cred_types' : [1, 2], / CWT Claims Set (CCS) and X.509 certificate / e'id_cred_types' : [4, 34], / kid and x5t / e'app_prof' : e'APP-PROF-WK-BASIC-CS-2-X509' }¶
This application profile is aligned with the example trace of EDHOC compiled in Section 3 of [RFC9529].¶
6.4. Well-Known Application Profile WK-BASIC_CS_0_X509
{ e'methods' : [0, 3], / EDHOC Method Types 0 and 3 / e'cipher_suites' : 0, / EDHOC Cipher Suite 0 / e'cred_types' : [1, 2], / CWT Claims Set (CCS) and X.509 certificate / e'id_cred_types' : [4, 34], / kid and x5t / e'app_prof' : e'APP-PROF-WK-BASIC-CS-0-X509' }¶
This application profile is aligned with the example trace of EDHOC compiled in Section 2 of [RFC9529].¶
6.5. Well-Known Application Profile WK-BASIC_CS_2_C509
{ e'methods' : [0, 3], / EDHOC Method Types 0 and 3 / e'cipher_suites' : 2, / EDHOC Cipher Suite 2 / e'cred_types' : [1, e'c509_cert'], / CWT Claims Set (CCS) and C509 certificate / e'id_cred_types' : [4, e'c5t'], / kid and c5t / e'app_prof' : e'APP-PROF-WK-BASIC-CS-2-C509' }¶
6.6. Well-Known Application Profile WK-BASIC_CS_0_C509
{ e'methods' : [0, 3], / EDHOC Method Types 0 and 3 / e'cipher_suites' : 0, / EDHOC Cipher Suite 0 / e'cred_types' : [1, e'c509_cert'], / CWT Claims Set (CCS) and C509 certificate / e'id_cred_types' : [4, e'c5t'], / kid and c5t / e'app_prof' : e'APP-PROF-WK-BASIC-CS-0-C509' }¶
6.7. Well-Known Application Profile WK-INTERMEDIATE_CS_2
{ e'methods' : [0, 3], / EDHOC Method Types 0 and 3 / e'cipher_suites' : 2, / EDHOC Cipher Suite 2 / e'cred_types' : [1, 2, e'c509_cert'], / CWT Claims Set (CCS), X.509 certificate, and C509 certificate / e'id_cred_types' : [4, 14, 34, 33, e'c5t', e'c5c'], / kid, kccs, x5t, x5chain, c5t, and c5c / e'app_prof' : e'APP-PROF-WK-INTERMEDIATE-CS-2' }¶
This application profile is aligned with the example trace of EDHOC compiled in Section 3 of [RFC9529].¶
6.8. Well-Known Application Profile WK-INTERMEDIATE_CS_0
{ e'methods' : [0, 3], / EDHOC Method Types 0 and 3 / e'cipher_suites' : 0, / EDHOC Cipher Suite 0 / e'cred_types' : [1, 2, e'c509_cert'], / CWT Claims Set (CCS), X.509 certificate, and C509 certificate / e'id_cred_types' : [4, 14, 34, 33, e'c5t', e'c5c'], / kid, kccs, x5t, x5chain, c5t, and c5c / e'app_prof' : e'APP-PROF-WK-INTERMEDIATE-CS-0' }¶
This application profile is aligned with the example trace of EDHOC compiled in Section 2 of [RFC9529].¶
6.9. Well-Known Application Profile WK-ADVANCED
{ e'methods' : [0, 1, 2, 3], / EDHOC Method Types 0, 1, 2, and 3 / e'cipher_suites' : [0, 1, 2, 3], / EDHOC Cipher Suites 0, 1, 2, and 3 / e'cred_types' : [1, 0, 2, e'c509_cert'], / CWT Claims Set (CCS), CWT, X.509 certificate, and C509 certificate / e'id_cred_types' : [4, 14, 13, 34, 33, e'c5t', e'c5c'], / kid, kccs, kcwt, x5t, x5chain, c5t, and c5c / e'app_prof' : e'APP-PROF-WK-ADVANCED' }¶
This application profile is aligned with the example traces of EDHOC compiled in Sections 2 and 3 of [RFC9529].¶
7. EDHOC Well-known Application Profiles
This document defines the following identifiers of well-known EDHOC application profiles.¶
Profile ID | Name | Description | Reference |
---|---|---|---|
0 | WK-MINIMAL-CS-2 | Method 3; Cipher Suite 2; CCS; kid | [RFC-XXXX] |
1 | WK-MINIMAL-CS-0 | Method 3; Cipher Suite 0; CCS; kid | [RFC-XXXX] |
2 | WK-BASIC-CS-2-X509 | Methods (0, 3); Cipher Suite 2; (CCS, X.509 certificates); (kid, x5t) | [RFC-XXXX] |
3 | WK-BASIC-CS-0-X509 | Methods (0, 3); Cipher Suite 0; (CCS, X.509 certificates); (kid, x5t) | [RFC-XXXX] |
4 | WK-BASIC-CS-2-C509 | Methods (0, 3); Cipher Suite 2; (CCS, C509 certificates); (kid, c5t) | [RFC-XXXX] |
5 | WK-BASIC-CS_0-C509 | Methods (0, 3); Cipher Suite 0; (CCS, C509 certificates); (kid, c5t) | [RFC-XXXX] |
6 | WK-INTERMEDIATE-CS-2 | Methods (0, 3); Cipher Suite 2; (CCS, X.509/C509 certificates); (kid, kccs, x5t, x5chain, c5t, c5c) | [RFC-XXXX] |
7 | WK-INTERMEDIATE-CS-0 | Methods (0, 3); Cipher Suite 0; (CCS, X.509/C509 certificates); (kid, kccs, x5t, x5chain, c5t, c5c) | [RFC-XXXX] |
8 | WK-ADVANCED | Methods (0, 1, 2, 3); Cipher Suites (0, 1, 2, 3); (CCS, CWT, X.509/C509 certificates); (kid, kccs, kcwt, x5t, x5chain, c5t, c5c) | [RFC-XXXX] |
8. EDHOC Endpoint Identity Types
This document defines the following identifier of type of endpoint identity for EDHOC.¶
Name | CBOR label | Description | Reference |
---|---|---|---|
EUI-64 | 0 | An EUI-64 identity | [RFC-XXXX][RFC4291] |
9. EDHOC Transports
This document defines the following identifiers of means for transporting EDHOC messages.¶
Transport ID | Name | Description | Reference |
---|---|---|---|
0 | CoAP over UDP | EDHOC messages are transported as payload of CoAP messages, in turn transported over UDP | [RFC7252], Appendix A.2 of [RFC9528] |
1 | CoAP over TCP | EDHOC messages are transported as payload of CoAP messages, in turn transported over TCP | [RFC7252][RFC8323] |
2 | CoAP over WebSockets | EDHOC messages are transported as payload of CoAP messages, in turn transported over WebSockets | [RFC7252][RFC8323] |
11. IANA Considerations
This document has the following actions for IANA.¶
Note to RFC Editor: Please replace all occurrences of "[RFC-XXXX]" with the RFC number of this specification and delete this paragraph.¶
11.1. Media Type Registrations
IANA is asked to register the media type "application/edhoc-app-profile+cbor-seq". This registration follows the procedures specified in [RFC6838].¶
Type name: application¶
Subtype name: edhoc-app-profile+cbor-seq¶
Required parameters: N/A¶
Optional parameters: N/A¶
Encoding considerations: Must be encoded as a CBOR sequence [RFC8742] of CBOR maps [RFC8949]. Each element of each CBOR map is also defined as an element of the CBOR-encoded EDHOC_Information object from Section 3.4 of [I-D.ietf-ace-edhoc-oscore-profile].¶
Security considerations: See Section 10 of [RFC-XXXX].¶
Interoperability considerations: N/A¶
Published specification: [RFC-XXXX]¶
Applications that use this media type: Applications that need to describe, distribute, and store a representation of an EDHOC application profile (see Section 3.9 of [RFC9528]).¶
Fragment identifier considerations: N/A¶
Additional information: N/A¶
Person & email address to contact for further information: LAKE WG mailing list (lake@ietf.org) or IETF Applications and Real-Time Area (art@ietf.org)¶
Intended usage: COMMON¶
Restrictions on usage: None¶
Author/Change controller: IETF¶
Provisional registration: No¶
11.2. CoAP Content-Formats Registry
IANA is asked to add the following entry to the "CoAP Content-Formats" registry within the "Constrained RESTful Environments (CoRE) Parameters" registry group.¶
Content Type: application/edhoc-app-profile+cbor-seq¶
Content Coding: -¶
ID: TBD¶
Reference: [RFC-XXXX]¶
11.3. Target Attributes Registry
IANA is asked to register the following entries in the "Target Attributes" registry within the "Constrained RESTful Environments (CoRE) Parameters", as per [RFC9423].¶
-
Attribute Name: ed-max-msgsize¶
-
Brief Description: The admitted maximum size of EDHOC messages in bytes¶
-
Change Controller: IETF¶
-
Reference: [RFC-XXXX]¶
-
Attribute Name: ed-coap-cf¶
-
Brief Description: Requested use of the CoAP Content-Format Option in CoAP messages whose payload includes exclusively an EDHOC message, possibly prepended by an EDHOC connection identifier¶
-
Change Controller: IETF¶
-
Reference: [RFC-XXXX]¶
-
Attribute Name: ed-idep-t¶
-
Brief Description: A supported type of endpoint identity for EDHOC¶
-
Change Controller: IETF¶
-
Reference: [RFC-XXXX]¶
-
Attribute Name: ed-tp¶
-
Brief Description: A supported means for transporting EDHOC messages¶
-
Change Controller: IETF¶
-
Reference: [RFC-XXXX]¶
11.4. EDHOC Information Registry
IANA is asked to register the following entries in the "EDHOC Information" registry defined in [I-D.ietf-ace-edhoc-oscore-profile].¶
-
Name: max_msgsize¶
-
CBOR label: 14¶
-
CBOR type: uint¶
-
Registry:¶
-
Description: The admitted maximum size of EDHOC messages in bytes¶
-
Name: coap_cf¶
-
CBOR label: 15¶
-
CBOR type: True or False¶
-
Registry:¶
-
Description: Requested use of the CoAP Content-Format Option in CoAP messages whose payload includes exclusively an EDHOC message, possibly prepended by an EDHOC connection identifier¶
-
Name: id_ep_types¶
-
CBOR label: 16¶
-
CBOR type: int or array¶
-
Registry: EDHOC Endpoint Identity Types¶
-
Description: Set of supported types of endpoint identities for EDHOC¶
-
Specification: [RFC-XXXX]¶
-
Name: transports¶
-
CBOR label: 17¶
-
CBOR type: int or array¶
-
Registry: EDHOC Transports Registry¶
-
Description: Set of supported means for transporting EDHOC messages¶
-
Specification: [RFC-XXXX]¶
11.5. EDHOC Application Profiles Registry
IANA is requested to create a new "EDHOC Application Profiles" registry within the "Ephemeral Diffie-Hellman Over COSE (EDHOC)" registry group defined in [RFC9528].¶
The registration policy is either "Private Use", "Standards Action with Expert Review", or "Specification Required" per Section 4.6 of [RFC8126]. "Expert Review" guidelines are provided in Section 11.8.¶
All assignments according to "Standards Action with Expert Review" are made on a "Standards Action" basis per Section 4.9 of [RFC8126], with Expert Review additionally required per Section 4.5 of [RFC8126]. The procedure for early IANA allocation of Standards Track code points defined in [RFC7120] also applies. When such a procedure is used, IANA will ask the designated expert(s) to approve the early allocation before registration. In addition, WG chairs are encouraged to consult the expert(s) early during the process outlined in Section 3.1 of [RFC7120].¶
The columns of this registry are:¶
-
Profile ID: This field contains the value used to identify the EDHOC application profile. These values MUST be unique. The value can be a positive integer or a negative integer. Different ranges of values use different registration policies [RFC8126]. Integer values from -24 to 23 are designated as "Standards Action With Expert Review". Integer values from -65536 to -25 and from 24 to 65535 are designated as "Specification Required". Integer values smaller than -65536 and greater than 65535 are marked as "Private Use".¶
-
Name: This field contains the name of the EDHOC application profile.¶
-
Description: This field contains a short description of the EDHOC application profile.¶
-
Reference: This field contains a pointer to the public specification for the EDHOC application profile.¶
This registry has been initially populated with the values in Table 3.¶
11.6. EDHOC Endpoint Identity Types Registry
IANA is requested to create a new "EDHOC Endpoint Identity Types" registry within the "Ephemeral Diffie-Hellman Over COSE (EDHOC)" registry group defined in [RFC9528].¶
The registration policy is either "Private Use", "Standards Action with Expert Review", or "Specification Required" per Section 4.6 of [RFC8126]. "Expert Review" guidelines are provided in Section 11.8.¶
All assignments according to "Standards Action with Expert Review" are made on a "Standards Action" basis per Section 4.9 of [RFC8126], with Expert Review additionally required per Section 4.5 of [RFC8126]. The procedure for early IANA allocation of Standards Track code points defined in [RFC7120] also applies. When such a procedure is used, IANA will ask the designated expert(s) to approve the early allocation before registration. In addition, WG chairs are encouraged to consult the expert(s) early during the process outlined in Section 3.1 of [RFC7120].¶
The columns of this registry are:¶
-
Name: This field contains the name of the EDHOC endpoint identity type.¶
-
CBOR Label: The value to be used to identify this EDHOC endpoint identity type. These values MUST be unique. The value can be a positive integer or a negative integer. Different ranges of values use different registration policies [RFC8126]. Integer values from -24 to 23 are designated as "Standards Action With Expert Review". Integer values from -65536 to -25 and from 24 to 65535 are designated as "Specification Required". Integer values smaller than -65536 and greater than 65535 are marked as "Private Use".¶
-
Description: This field contains a short description of the EDHOC endpoint identity type.¶
-
Reference: This field contains a pointer to the public specification for the EDHOC endpoint identity type.¶
This registry has been initially populated with the values in Table 4.¶
11.7. EDHOC Transport Registry
IANA is requested to create a new "EDHOC Transport" registry within the "Ephemeral Diffie-Hellman Over COSE (EDHOC)" registry group defined in [RFC9528].¶
The registration policy is either "Private Use", "Standards Action with Expert Review", or "Specification Required" per Section 4.6 of [RFC8126]. "Expert Review" guidelines are provided in Section 11.8.¶
All assignments according to "Standards Action with Expert Review" are made on a "Standards Action" basis per Section 4.9 of [RFC8126], with Expert Review additionally required per Section 4.5 of [RFC8126]. The procedure for early IANA allocation of Standards Track code points defined in [RFC7120] also applies. When such a procedure is used, IANA will ask the designated expert(s) to approve the early allocation before registration. In addition, WG chairs are encouraged to consult the expert(s) early during the process outlined in Section 3.1 of [RFC7120].¶
The columns of this registry are:¶
-
Transport ID: The value to be used to identify this means for transporting EDHOC messages. These values MUST be unique. The value can be a positive integer or a negative integer. Different ranges of values use different registration policies [RFC8126]. Integer values from -24 to 23 are designated as "Standards Action With Expert Review". Integer values from -65536 to -25 and from 24 to 65535 are designated as "Specification Required". Integer values smaller than -65536 and greater than 65535 are marked as "Private Use".¶
-
Name: This field contains the name of the means for transporting EDHOC messages.¶
-
Description: This field contains a short description of the means used for transporting EDHOC messages.¶
-
Reference: This field contains a pointer to the public specification for the means used for transporting EDHOC messages.¶
This registry has been initially populated with the values in Table 5.¶
11.8. Expert Review Instructions
"Standards Action with Expert Review" and "Specification Required" are two of the registration policies defined for the IANA registries established in this document. This section gives some general guidelines for what the experts should be looking for, but they are being designated as experts for a reason so they should be given substantial latitude.¶
Expert reviewers should take into consideration the following points:¶
-
Clarity and correctness of registrations. Experts are expected to check the clarity of purpose and use of the requested entries. Experts need to make sure that the object of registration (i.e., an EDHOC application profile, an EDHOC endpoint identity type, or a means for transporting EDHOC messages) is clearly defined in the corresponding specification. Entries that do not meet these objective of clarity and completeness must not be registered.¶
-
Point squatting should be discouraged. Reviewers are encouraged to get sufficient information for registration requests to ensure that the usage is not going to duplicate one that is already registered and that the point is likely to be used in deployments. The zones tagged as "Private Use" are intended for testing purposes and closed environments. Code points in other ranges should not be assigned for testing.¶
-
Specifications are required for the "Standards Action With Expert Review" range of point assignment. Specifications should exist for "Specification Required" ranges, but early assignment before a specification is available is considered to be permissible. When specifications are not provided, the description provided needs to have sufficient information to identify what the point is being used for.¶
-
Experts should take into account the expected usage of fields when approving point assignment. Documents published via Standards Action can also register points outside the Standards Action range. The length of the encoded value should be weighed against how many code points of that length are left, the size of device it will be used on, and the number of code points left that encode to that size.¶
12. References
12.1. Normative References
- [COSE.Header.Parameters]
- IANA, "COSE Header Parameters", <https://www.iana.org/assignments/cose/cose.xhtml#header-parameters>.
- [I-D.ietf-ace-edhoc-oscore-profile]
- Selander, G., Mattsson, J. P., Tiloca, M., and R. Höglund, "Ephemeral Diffie-Hellman Over COSE (EDHOC) and Object Security for Constrained Environments (OSCORE) Profile for Authentication and Authorization for Constrained Environments (ACE)", Work in Progress, Internet-Draft, draft-ietf-ace-edhoc-oscore-profile-06, , <https://datatracker.ietf.org/doc/html/draft-ietf-ace-edhoc-oscore-profile-06>.
- [I-D.ietf-core-oscore-edhoc]
- Palombini, F., Tiloca, M., Höglund, R., Hristozov, S., and G. Selander, "Using Ephemeral Diffie-Hellman Over COSE (EDHOC) with the Constrained Application Protocol (CoAP) and Object Security for Constrained RESTful Environments (OSCORE)", Work in Progress, Internet-Draft, draft-ietf-core-oscore-edhoc-11, , <https://datatracker.ietf.org/doc/html/draft-ietf-core-oscore-edhoc-11>.
- [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/rfc/rfc2119>.
- [RFC4291]
- Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, DOI 10.17487/RFC4291, , <https://www.rfc-editor.org/rfc/rfc4291>.
- [RFC6690]
- Shelby, Z., "Constrained RESTful Environments (CoRE) Link Format", RFC 6690, DOI 10.17487/RFC6690, , <https://www.rfc-editor.org/rfc/rfc6690>.
- [RFC6838]
- Freed, N., Klensin, J., and T. Hansen, "Media Type Specifications and Registration Procedures", BCP 13, RFC 6838, DOI 10.17487/RFC6838, , <https://www.rfc-editor.org/rfc/rfc6838>.
- [RFC7120]
- Cotton, M., "Early IANA Allocation of Standards Track Code Points", BCP 100, RFC 7120, DOI 10.17487/RFC7120, , <https://www.rfc-editor.org/rfc/rfc7120>.
- [RFC7252]
- Shelby, Z., Hartke, K., and C. Bormann, "The Constrained Application Protocol (CoAP)", RFC 7252, DOI 10.17487/RFC7252, , <https://www.rfc-editor.org/rfc/rfc7252>.
- [RFC8126]
- Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, , <https://www.rfc-editor.org/rfc/rfc8126>.
- [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/rfc/rfc8174>.
- [RFC8288]
- Nottingham, M., "Web Linking", RFC 8288, DOI 10.17487/RFC8288, , <https://www.rfc-editor.org/rfc/rfc8288>.
- [RFC8323]
- Bormann, C., Lemay, S., Tschofenig, H., Hartke, K., Silverajan, B., and B. Raymor, Ed., "CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets", RFC 8323, DOI 10.17487/RFC8323, , <https://www.rfc-editor.org/rfc/rfc8323>.
- [RFC8610]
- Birkholz, H., Vigano, C., and C. Bormann, "Concise Data Definition Language (CDDL): A Notational Convention to Express Concise Binary Object Representation (CBOR) and JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610, , <https://www.rfc-editor.org/rfc/rfc8610>.
- [RFC8613]
- Selander, G., Mattsson, J., Palombini, F., and L. Seitz, "Object Security for Constrained RESTful Environments (OSCORE)", RFC 8613, DOI 10.17487/RFC8613, , <https://www.rfc-editor.org/rfc/rfc8613>.
- [RFC8742]
- Bormann, C., "Concise Binary Object Representation (CBOR) Sequences", RFC 8742, DOI 10.17487/RFC8742, , <https://www.rfc-editor.org/rfc/rfc8742>.
- [RFC8949]
- Bormann, C. and P. Hoffman, "Concise Binary Object Representation (CBOR)", STD 94, RFC 8949, DOI 10.17487/RFC8949, , <https://www.rfc-editor.org/rfc/rfc8949>.
- [RFC9200]
- Seitz, L., Selander, G., Wahlstroem, E., Erdtman, S., and H. Tschofenig, "Authentication and Authorization for Constrained Environments Using the OAuth 2.0 Framework (ACE-OAuth)", RFC 9200, DOI 10.17487/RFC9200, , <https://www.rfc-editor.org/rfc/rfc9200>.
- [RFC9423]
- Bormann, C., "Constrained RESTful Environments (CoRE) Target Attributes Registry", RFC 9423, DOI 10.17487/RFC9423, , <https://www.rfc-editor.org/rfc/rfc9423>.
- [RFC9528]
- Selander, G., Preuß Mattsson, J., and F. Palombini, "Ephemeral Diffie-Hellman Over COSE (EDHOC)", RFC 9528, DOI 10.17487/RFC9528, , <https://www.rfc-editor.org/rfc/rfc9528>.
12.2. Informative References
- [RFC9529]
- Selander, G., Preuß Mattsson, J., Serafin, M., Tiloca, M., and M. Vučinić, "Traces of Ephemeral Diffie-Hellman Over COSE (EDHOC)", RFC 9529, DOI 10.17487/RFC9529, , <https://www.rfc-editor.org/rfc/rfc9529>.
Appendix A. CDDL Model
This section is to be removed before publishing as an RFC.¶
Acknowledgments
The authors sincerely thank Christian Amsüss, Göran Selander, and Brian Sipos for their feedback and comments.¶
This work was supported by the Sweden's Innovation Agency VINNOVA within the EUREKA CELTIC-NEXT project CYPRESS.¶