--- 1/draft-ietf-ace-oscore-profile-12.txt 2020-10-27 10:13:36.771969405 -0700 +++ 2/draft-ietf-ace-oscore-profile-13.txt 2020-10-27 10:13:36.839971117 -0700 @@ -1,24 +1,24 @@ ACE Working Group F. Palombini Internet-Draft Ericsson AB Intended status: Standards Track L. Seitz -Expires: March 25, 2021 Combitech +Expires: April 30, 2021 Combitech G. Selander Ericsson AB M. Gunnarsson RISE - September 21, 2020 + October 27, 2020 OSCORE Profile of the Authentication and Authorization for Constrained Environments Framework - draft-ietf-ace-oscore-profile-12 + draft-ietf-ace-oscore-profile-13 Abstract This memo specifies a profile for the Authentication and Authorization for Constrained Environments (ACE) framework. It utilizes Object Security for Constrained RESTful Environments (OSCORE) to provide communication security and proof-of-possession for a key owned by the client and bound to an OAuth 2.0 access token. Status of This Memo @@ -29,59 +29,61 @@ 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 March 25, 2021. + This Internet-Draft will expire on April 30, 2021. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents - 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 4 3. Client-AS Communication . . . . . . . . . . . . . . . . . . . 6 3.1. C-to-AS: POST to token endpoint . . . . . . . . . . . . . 6 3.2. AS-to-C: Access Token . . . . . . . . . . . . . . . . . . 8 - 3.2.1. The OSCORE_Input_Material . . . . . . . . . . . . . . 13 - 4. Client-RS Communication . . . . . . . . . . . . . . . . . . . 16 - 4.1. C-to-RS: POST to authz-info endpoint . . . . . . . . . . 17 - 4.1.1. The Nonce 1 Parameter . . . . . . . . . . . . . . . . 18 - 4.2. RS-to-C: 2.01 (Created) . . . . . . . . . . . . . . . . . 18 - 4.2.1. The Nonce 2 Parameter . . . . . . . . . . . . . . . . 20 - 4.3. OSCORE Setup . . . . . . . . . . . . . . . . . . . . . . 20 + 3.2.1. The OSCORE_Input_Material . . . . . . . . . . . . . . 12 + 4. Client-RS Communication . . . . . . . . . . . . . . . . . . . 15 + 4.1. C-to-RS: POST to authz-info endpoint . . . . . . . . . . 16 + 4.1.1. The Nonce 1 Parameter . . . . . . . . . . . . . . . . 17 + 4.1.2. The ace_client_recipientid Parameter . . . . . . . . 17 + 4.2. RS-to-C: 2.01 (Created) . . . . . . . . . . . . . . . . . 17 + 4.2.1. The Nonce 2 Parameter . . . . . . . . . . . . . . . . 19 + 4.2.2. The ace_server_recipientid Parameter . . . . . . . . 19 + 4.3. OSCORE Setup . . . . . . . . . . . . . . . . . . . . . . 19 4.4. Access rights verification . . . . . . . . . . . . . . . 22 5. Secure Communication with AS . . . . . . . . . . . . . . . . 22 - 6. Discarding the Security Context . . . . . . . . . . . . . . . 23 - 7. Security Considerations . . . . . . . . . . . . . . . . . . . 24 + 6. Discarding the Security Context . . . . . . . . . . . . . . . 22 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 23 8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 25 - 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 - 9.1. ACE Profile Registry . . . . . . . . . . . . . . . . . . 26 + 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 + 9.1. ACE Profile Registry . . . . . . . . . . . . . . . . . . 25 9.2. OAuth Parameters Registry . . . . . . . . . . . . . . . . 26 9.3. OAuth Parameters CBOR Mappings Registry . . . . . . . . . 26 9.4. OSCORE Security Context Parameters Registry . . . . . . . 27 9.5. CWT Confirmation Methods Registry . . . . . . . . . . . . 28 9.6. JWT Confirmation Methods Registry . . . . . . . . . . . . 28 9.7. Expert Review Instructions . . . . . . . . . . . . . . . 28 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 29 10.1. Normative References . . . . . . . . . . . . . . . . . . 29 10.2. Informative References . . . . . . . . . . . . . . . . . 30 Appendix A. Profile Requirements . . . . . . . . . . . . . . . . 31 @@ -159,41 +161,48 @@ This profile requires a client to retrieve an access token from the AS for the resource it wants to access on an RS, by sending an access token request to the token endpoint, as specified in section 5.6 of [I-D.ietf-ace-oauth-authz]. The access token request and response MUST be confidentiality-protected and ensure authenticity. This profile RECOMMENDS the use of OSCORE between client and AS, but other protocols (such as TLS or DTLS) can be used as well. Once the client has retrieved the access token, it generates a nonce - N1 and posts both the token and N1 to the RS using the authz-info - endpoint and mechanisms specified in section 5.8 of - [I-D.ietf-ace-oauth-authz] and Content-Format = application/ace+cbor. - When using this profile, the communication with the authz-info - endpoint is not protected, except for update of access rights. + N1. The client also generates its OSCORE Recipient ID (see + Section 3.1 of [RFC8613]), ID1, for use with the keying material + associated to the RS. The client posts the token, N1 and its + Recipient ID to the RS using the authz-info endpoint and mechanisms + specified in section 5.8 of [I-D.ietf-ace-oauth-authz] and Content- + Format = application/ace+cbor. When using this profile, the + communication with the authz-info endpoint is not protected, except + for update of access rights. If the access token is valid, the RS replies to this request with a 2.01 (Created) response with Content-Format = application/ace+cbor, - which contains a nonce N2 in a CBOR map. Moreover, the server - concatenates the input salt received in the token, N1, and N2 to - obtain the Master Salt of the OSCORE Security Context (see section 3 - of [RFC8613]). The RS then derives the complete Security Context - associated with the received token from it plus the parameters - received in the access token from the AS, following section 3.2 of - [RFC8613]. + which contains a nonce N2 and its newly generated OSCORE Recipient + ID, ID2, for use with the keying material associated to the client. + Moreover, the server concatenates the input salt received in the + token, N1, and N2 to obtain the Master Salt of the OSCORE Security + Context (see section 3 of [RFC8613]). The RS then derives the + complete Security Context associated with the received token from the + Master Salt, the OSCORE Recipient ID generated by the client (set as + its OSCORE Sender ID), its own OSCORE Recipient ID, plus the + parameters received in the access token from the AS, following + section 3.2 of [RFC8613]. - After receiving the nonce N2, the client concatenates the input salt - (received from the AS), N1 and N2 to obtain the Master Salt of the - OSCORE Security Context (see section 3 of [RFC8613]). The client - then derives the complete Security Context from the nonces plus the - parameters received from the AS. + In a similar way, after receiving the nonce N2, the client + concatenates the input salt, N1 and N2 to obtain the Master Salt of + the OSCORE Security Context. The client then derives the complete + Security Context from the Master Salt, the OSCORE Recipient ID + generated by the RS (set as its OSCORE Sender ID), its own OSCORE + Recipient ID, plus the parameters received from the AS. Finally, the client sends a request protected with OSCORE to the RS. If the request verifies, the server stores the complete Security Context state that is ready for use in protecting messages, and uses it in the response, and in further communications with the client, until token expiration. This Security Context is discarded when a token (whether the same or different) is used to successfully derive a new Security Context for that client. The use of random nonces during the exchange prevents the reuse of an @@ -209,40 +218,39 @@ [RFC8613]). Therefore, the main requirement for the nonces is that they have a good amount of randomness. If random nonces were not used, a node re-using a non-expired old token would be susceptible to on-path attackers provoking the creation of OSCORE messages using old AEAD keys and nonces. After the whole message exchange has taken place, the client can contact the AS to request an update of its access rights, sending a similar request to the token endpoint that also includes an identifier so that the AS can find the correct OSCORE security - material it has previously shared with the Client. This specific - identifier, which [I-D.ietf-ace-oauth-authz] encodes as a bstr, is - formatted to include two OSCORE identifiers, namely ID context and - client ID, that are necessary to determine the correct OSCORE Input - material. + material it has previously shared with the client. This specific + identifier, encoded as a byte string, is assigned by the AS to be + unique in the sets of its OSCORE Security Contexts, and is not used + as input material to derive the full OSCORE Security Context. An overview of the profile flow for the OSCORE profile is given in Figure 1. The names of messages coincide with those of [I-D.ietf-ace-oauth-authz] when applicable. C RS AS | | | | ----- POST /token ----------------------------> | | | | | <---------------------------- Access Token ----- | | + Access Information | | ---- POST /authz-info ---> | | - | (access_token, N1) | | + | (access_token, N1, ID1) | | | | | - | <--- 2.01 Created (N2) --- | | + | <- 2.01 Created (N2, ID2)- | | | | | /Sec Context /Sec Context | derivation/ derivation/ | | | | | ---- OSCORE Request -----> | | | | | | /proof-of-possession | | Sec Context storage/ | | | | | <--- OSCORE Response ----- | | @@ -289,63 +297,50 @@ { "req_aud" : "tempSensor4711", "scope" : "read" } Figure 2: Example C-to-AS POST /token request for an access token bound to a symmetric key. If the client wants to update its access rights without changing an existing OSCORE Security Context, it MUST include in its POST request - to the token endpoint a req_cnf object. The req_cnf MUST include a - kid field carrying a bstr-wrapped CBOR array object containing the - client's identifier (assigned as discussed in Section 3.2) and the - context identifier (if assigned as discussed in Section 3.2). The - CBOR array is defined in Figure 3, and follows the notation of - [RFC8610]. These identifiers, together with other information such - as audience (see Section 5.6.1 of [I-D.ietf-ace-oauth-authz]), can be - used by the AS to determine the shared secret bound to the proof-of- - possession token and therefore MUST identify a symmetric key that was - previously generated by the AS as a shared secret for the - communication between the client and the RS. The AS MUST verify that - the received value identifies a proof-of-possession key that has - previously been issued to the requesting client. If that is not the - case, the Client-to-AS request MUST be declined with the error code - 'invalid_request' as defined in Section 5.6.3 of - [I-D.ietf-ace-oauth-authz]. - - kid_arr = [ - clientId, - ?ContextId - ] - - kid = bstr .cbor kid_arr - - Figure 3: CDDL Notation of kid for Update of Access Rights + to the token endpoint a req_cnf object. kid field carrying a CBOR + byte string containing the OSCORE_Input_Material Identifier (assigned + as discussed in Section 3.2). This identifier, together with other + information such as audience (see Section 5.6.1 of + [I-D.ietf-ace-oauth-authz]), can be used by the AS to determine the + shared secret bound to the proof-of-possession token and therefore + MUST identify a symmetric key that was previously generated by the AS + as a shared secret for the communication between the client and the + RS. The AS MUST verify that the received value identifies a proof- + of-possession key that has previously been issued to the requesting + client. If that is not the case, the Client-to-AS request MUST be + declined with the error code 'invalid_request' as defined in + Section 5.6.3 of [I-D.ietf-ace-oauth-authz]. An example of such a request, with payload in CBOR diagnostic notation without the tag and value abbreviations is reported in - Figure 4 - + Figure 3 Header: POST (Code=0.02) Uri-Host: "as.example.com" Uri-Path: "token" Content-Format: "application/ace+cbor" Payload: { "req_aud" : "tempSensor4711", "scope" : "write", "req_cnf" : { - "kid" : << ["myclient","contextid1"] >> + "kid" : h'01' } - Figure 4: Example C-to-AS POST /token request for updating rights to + Figure 3: Example C-to-AS POST /token request for updating rights to an access token bound to a symmetric key. 3.2. AS-to-C: Access Token After verifying the POST request to the token endpoint and that the client is authorized to obtain an access token corresponding to its access token request, the AS responds as defined in section 5.6.2 of [I-D.ietf-ace-oauth-authz]. If the client request was invalid, or not authorized, the AS returns an error response as described in section 5.6.3 of [I-D.ietf-ace-oauth-authz]. @@ -356,33 +351,30 @@ client MUST use OSCORE towards all resource servers for which this access token is valid, and follow Section 4.3 to derive the security context to run OSCORE. Usually it is assumed that constrained devices will be pre-configured with the necessary profile, so that this kind of profile negotiation can be omitted. Moreover, the AS MUST send the following data: o a master secret - o a server identifier - - o a client identifier + o an identifier of the OSCORE Input Material Additionally, the AS MAY send the following data, in the same response. o a context identifier o an AEAD algorithm o an HMAC-based key derivation function (HKDF) algorithm - o a salt o the OSCORE version number This data is transported in the the OSCORE_Input_Material. The OSCORE_Input_Material is a CBOR map object, defined in Section 3.2.1. This object is transported in the 'cnf' parameter of the access token response as defined in Section 3.2 of [I-D.ietf-ace-oauth-params], as the value of a field named 'osc', registered in Section 9.5 and Section 9.6. @@ -380,202 +372,177 @@ o the OSCORE version number This data is transported in the the OSCORE_Input_Material. The OSCORE_Input_Material is a CBOR map object, defined in Section 3.2.1. This object is transported in the 'cnf' parameter of the access token response as defined in Section 3.2 of [I-D.ietf-ace-oauth-params], as the value of a field named 'osc', registered in Section 9.5 and Section 9.6. - The AS MUST assign an identifier to the RS (server identifier), and - to the client (client identifier), and MAY assign an identifier to - the context (context identifier). These identifiers are then used as - Sender ID, Recipient ID and ID Context in the OSCORE context as - described in section 3.1 of [RFC8613]: specifically, the server - identifier is used as Sender ID of the node acting as RS in this - profile, and the client identifier is used as Sender ID of the node - acting as ACE client. These parameters are sent as clientId, - serverId and (when assigned) contextId in the OSCORE_Input_Material. - ClientId and serverId MUST be included in the OSCORE_Input_Material, - contextId MUST be included when assigned. The applications need to - consider that these identifiers are sent in the clear and may reveal - information about the endpoints, as mentioned in section 12.8 of - [RFC8613]. The pair (client identifier, context identifier) MUST be - unique in the set of all clients for a single RS. + The AS MAY assign an identifier to the context (context identifier). + This identifier is used as ID Context in the OSCORE context as + described in section 3.1 of [RFC8613]. If assigned, this parameters + MUST be communicated as the 'contextId' field in the + OSCORE_Input_Material. The applications needs to consider that this + identifier is sent in the clear and may reveal information about the + endpoints, as mentioned in section 12.8 of [RFC8613]. - The master secret MUST be communicated as the 'ms' field in the 'osc' - field in the 'cnf' parameter of the access token response. If - included, the AEAD algorithm is sent in the 'alg' parameter in the + The master secret and the identifier of the OSCORE_Input_Material + MUST be communicated as the 'ms' and 'id' field in the 'osc' field in + the 'cnf' parameter of the access token response. If included, the + AEAD algorithm is sent in the 'alg' parameter in the OSCORE_Input_Material; the HKDF algorithm in the 'hkdf' parameter of the OSCORE_Input_Material; a salt in the 'salt' parameter of the OSCORE_Input_Material; and the OSCORE version in the 'version' parameter of the OSCORE_Input_Material. The same parameters MUST be included in the claims associated with the access token. This profile RECOMMENDS the use of CBOR web token (CWT) as specified in [RFC8392]. If the token is a CWT, the same OSCORE_Input_Material structure defined above MUST be placed in the 'osc' field of the 'cnf' claim of this token. - We assume in this document that an RS is associated to one single AS, - which makes it possible for the AS to enforce uniqueness of - identifiers for each client sending requests to an RS. If this is - not the case, collisions of identifiers may occur at the RS, in which - case the RS needs to have a mechanism in place to disambiguate - identifiers or mitigate the effect of the collisions. - - Moreover, implementers of this specification need to be aware that if - other authentication mechanisms are used to set up OSCORE between the - same client and RS, that do not rely on AS assigning identifiers, - collisions may happen and need to be mitigated. A mitigation example - would be to use distinct namespaces of identifiers for different - authentication mechanisms. - The AS MUST send different OSCORE_Input_Material (and therefore different access tokens) to different authorized clients, in order for the RS to differentiate between clients. - Note that in Section 4.3 C sets the Sender ID of its Security Context - to the clientId value received and the Recipient ID to the serverId - value, and RS does the opposite. - - Figure 5 shows an example of an AS response, with payload in CBOR + Figure 4 shows an example of an AS response, with payload in CBOR diagnostic notation without the tag and value abbreviations. The access token has been truncated for readability. Header: Created (Code=2.01) Content-Type: "application/ace+cbor" Payload: { "access_token" : h'8343a1010aa2044c53 ... (remainder of access token (CWT) omitted for brevity)', "profile" : "coap_oscore", "expires_in" : "3600", "cnf" : { "osc" : { - "alg" : "AES-CCM-16-64-128", - "clientId" : h'00', - "serverId" : h'01', + "id" : h'01', "ms" : h'f9af838368e353e78888e1426bd94e6f' } } } - Figure 5: Example AS-to-C Access Token response with OSCORE profile. + Figure 4: Example AS-to-C Access Token response with OSCORE profile. - Figure 6 shows an example CWT Claims Set, including the relevant + Figure 5 shows an example CWT Claims Set, including the relevant OSCORE parameters in the 'cnf' claim, in CBOR diagnostic notation without tag and value abbreviations. { "aud" : "tempSensorInLivingRoom", "iat" : "1360189224", "exp" : "1360289224", "scope" : "temperature_g firmware_p", "cnf" : { "osc" : { - "alg" : "AES-CCM-16-64-128", - "clientId" : h'00', - "serverId" : h'01', - "ms" : h'f9af838368e353e78888e1426bd94e6f' + "ms" : h'f9af838368e353e78888e1426bd94e6f', + "id" : h'01' + } } } - Figure 6: Example CWT Claims Set with OSCORE parameters. + Figure 5: Example CWT Claims Set with OSCORE parameters. - The same CWT Claims Set as in Figure 6, using the value abbreviations + The same CWT Claims Set as in Figure 5, using the value abbreviations defined in [I-D.ietf-ace-oauth-authz] and [RFC8747] and encoded in - CBOR is shown in Figure 7. The bytes in hexadecimal are reported in + CBOR is shown in Figure 6. The bytes in hexadecimal are reported in the first column, while their corresponding CBOR meaning is reported after the '#' sign on the second column, for easiness of readability. NOTE TO THE RFC EDITOR: before publishing, it should be checked (and in case fixed) that the values used below (which are not yet registered) are the final values registered in IANA. A5 # map(5) - 03 # unsigned(3) + 63 # text(3) + 617564 # "aud" 76 # text(22) 74656D7053656E736F72496E4C6976696E67526F6F6D # "tempSensorInLivingRoom" - 06 # unsigned(6) - 1A 5112D728 # unsigned(1360189224) - 04 # unsigned(4) - 1A 51145DC8 # unsigned(1360289224) - 09 # unsigned(9) + 63 # text(3) + 696174 # "iat" + 6A # text(10) + 31333630313839323234 # "1360189224" + 63 # text(3) + 657870 # "exp" + 6A # text(10) + 31333630323839323234 # "1360289224" + 65 # text(5) + 73636F7065 # "scope" 78 18 # text(24) 74656D70657261747572655F67206669726D776172655F70 # "temperature_g firmware_p" - 08 # unsigned(8) + 63 # text(3) + 636E66 # "cnf" A1 # map(1) - 04 # unsigned(4) - A4 # map(4) - 05 # unsigned(5) - 0A # unsigned(10) - 02 # unsigned(2) - 46 # bytes(6) - 636C69656E74 # "client" - 03 # unsigned(3) - 46 # bytes(6) - 736572766572 # "server" - 01 # unsigned(1) + 63 # text(3) + 6F7363 # "osc" + A2 # map(2) + 62 # text(2) + 6D73 # "ms" 50 # bytes(16) F9AF838368E353E78888E1426BD94E6F # "\xF9\xAF\x83\x83h\xE3S\xE7 \x88\x88\xE1Bk\xD9No" + 62 # text(2) + 6964 # "id" + 41 # bytes(1) + 01 # "\x01" - Figure 7: Example CWT Claims Set with OSCORE parameters, CBOR + Figure 6: Example CWT Claims Set with OSCORE parameters, CBOR encoded. If the client has requested an update to its access rights using the same OSCORE Security Context, which is valid and authorized, the AS MUST omit the 'cnf' parameter in the response, and MUST carry the - client identifier and the context identifier (if it was set and - included in the initial access token response by the AS) in the 'kid' - field in the 'cnf' parameter of the token, with the same structure - defined in Figure 3. These identifiers need to be included in the - token in order for the RS to identify the previously generated - Security Context. + OSCORE Input Material identifier in the 'kid' field in the 'cnf' + parameter of the token. This identifier needs to be included in the + token in order for the RS to identify the correct OSCORE Input + Material. - Figure 8 shows an example of such an AS response, with payload in + Figure 7 shows an example of such an AS response, with payload in CBOR diagnostic notation without the tag and value abbreviations. The access token has been truncated for readability. Header: Created (Code=2.01) Content-Type: "application/ace+cbor" Payload: { "access_token" : h'8343a1010aa2044c53 ... (remainder of access token (CWT) omitted for brevity)', "profile" : "coap_oscore", "expires_in" : "3600" } - Figure 8: Example AS-to-C Access Token response with OSCORE profile, + Figure 7: Example AS-to-C Access Token response with OSCORE profile, for update of access rights. - Figure 9 shows an example CWT Claims Set, containing the necessary + Figure 8 shows an example CWT Claims Set, containing the necessary OSCORE parameters in the 'cnf' claim for update of access rights, in CBOR diagnostic notation without tag and value abbreviations. { "aud" : "tempSensorInLivingRoom", "iat" : "1360189224", "exp" : "1360289224", "scope" : "temperature_h", "cnf" : { - "kid" : h'43814100' + "kid" : h'01' } } - Figure 9: Example CWT Claims Set with OSCORE parameters for update of + Figure 8: Example CWT Claims Set with OSCORE parameters for update of access rights. 3.2.1. The OSCORE_Input_Material An OSCORE_Input_Material is an object that represents the input material to derive an OSCORE Security Context, i.e., the local set of information elements necessary to carry out the cryptographic operations in OSCORE (Section 3.1 of [RFC8613]). In particular, the OSCORE_Input_Material is defined to be serialized and transported between nodes, as specified by this document, but can also be used by @@ -592,82 +559,60 @@ | | label | | | | +-----------+-------+-------------+-------------------+-------------+ | version | 0 | unsigned | | OSCORE | | | | integer | | Version | | | | | | | | ms | 1 | byte string | | OSCORE | | | | | | Master | | | | | | Secret | | | | | | value | | | | | | | - | clientId | 2 | byte string | | OSCORE | - | | | | | Sender ID | - | | | | | value of | - | | | | | the client, | - | | | | | OSCORE | - | | | | | Recipient | - | | | | | ID value of | - | | | | | the server | - | | | | | | - | serverId | 3 | byte string | | OSCORE | - | | | | | Sender ID | - | | | | | value of | - | | | | | the server, | - | | | | | OSCORE | - | | | | | Recipient | - | | | | | ID value of | - | | | | | the client | + | id | 2 | byte string | | OSCORE | + | | | | | Input | + | | | | | Material | + | | | | | Identifier | | | | | | | - | hkdf | 4 | text string | [COSE.Algorithms] | OSCORE HKDF | + | hkdf | 3 | text string | [COSE.Algorithms] | OSCORE HKDF | | | | / integer | Values (HMAC- | value | | | | | based) | | | | | | | | - | alg | 5 | text string | [COSE.Algorithms] | OSCORE AEAD | + | alg | 4 | text string | [COSE.Algorithms] | OSCORE AEAD | | | | / integer | Values (AEAD) | Algorithm | | | | | | value | | | | | | | - | salt | 6 | byte string | | an input to | + | salt | 5 | byte string | | an input to | | | | | | OSCORE | | | | | | Master Salt | | | | | | value | | | | | | | - | contextId | 7 | byte string | | OSCORE ID | + | contextId | 6 | byte string | | OSCORE ID | | | | | | Context | | | | | | value | +-----------+-------+-------------+-------------------+-------------+ Table 1: OSCORE_Input_Material Parameters version: This parameter identifies the OSCORE Version number, which is an unsigned integer. For more information about this field, see section 5.4 of [RFC8613]. In JSON, the "version" value is an integer. In CBOR, the "version" type is int, and has label 0. ms: This parameter identifies the OSCORE Master Secret value, which is a byte string. For more information about this field, see section 3.1 of [RFC8613]. In JSON, the "ms" value is a Base64 encoded byte string. In CBOR, the "ms" type is bstr, and has label 1. - clientId: This parameter identifies a client identifier as a byte - string. This identifier is used as OSCORE Sender ID in the client - and OSCORE Recipient ID in the server. For more information about - this field, see section 3.1 of [RFC8613]. In JSON, the "clientId" - value is a Base64 encoded byte string. In CBOR, the "clientId" - type is bstr, and has label 2. - - serverId: This parameter identifies a server identifier as a byte - string. This identifier is used as OSCORE Sender ID in the server - and OSCORE Recipient ID in the client. For more information about - this field, see section 3.1 of [RFC8613]. In JSON, the "serverId" - value is a Base64 encoded byte string. In CBOR, the "serverId" - type is bstr, and has label 3. + id: This parameter identifies the OSCORE_Input_Material and is + encoded as a byte string. In JSON, the "id" value is a Base64 + encoded byte string. In CBOR, the "id" type is byte string, and + has label 8. hkdf: This parameter identifies the OSCORE HKDF Algorithm. For more information about this field, see section 3.1 of [RFC8613]. The values used MUST be registered in the IANA "COSE Algorithms" registry (see [COSE.Algorithms]) and MUST be HMAC-based HKDF algorithms. The value can either be the integer or the text string value of the HMAC-based HKDF algorithm in the "COSE Algorithms" registry. In JSON, the "hkdf" value is a case- sensitive ASCII string or an integer. In CBOR, the "hkdf" type is tstr or int, and has label 4. @@ -686,314 +631,353 @@ field, see section 3.1 of [RFC8613]. In JSON, the "salt" value is a Base64 encoded byte string. In CBOR, the "salt" type is bstr, and has label 6. contextId: This parameter identifies the security context as a byte string. This identifier is used as OSCORE ID Context. For more information about this field, see section 3.1 of [RFC8613]. In JSON, the "contextID" value is a Base64 encoded byte string. In CBOR, the "contextID" type is bstr, and has label 7. - An example of JSON OSCORE_Input_Material is given in Figure 10. + An example of JSON OSCORE_Input_Material is given in Figure 9. "osc" : { "alg" : "AES-CCM-16-64-128", - "clientId" : b64'AA', - "serverId" : b64'AQ', + "id" : b64'AQ==' "ms" : b64'+a+Dg2jjU+eIiOFCa9lObw' } - Figure 10: Example JSON OSCORE_Input_Material + Figure 9: Example JSON OSCORE_Input_Material The CDDL grammar describing the CBOR OSCORE_Input_Material is: OSCORE_Input_Material = { ? 0 => int, ; version ? 1 => bstr, ; ms - ? 2 => bstr, ; clientId - ? 3 => bstr, ; serverId - ? 4 => tstr / int, ; hkdf - ? 5 => tstr / int, ; alg - ? 6 => bstr, ; salt - ? 7 => bstr, ; contextId + ? 2 => bstr, ; id + ? 3 => tstr / int, ; hkdf + ? 4 => tstr / int, ; alg + ? 5 => bstr, ; salt + ? 6 => bstr, ; contextId * int / tstr => any } 4. Client-RS Communication The following subsections describe the details of the POST request and response to the authz-info endpoint between client and RS. The - client generates a nonce N1, and posts it together with the token - that includes the materials (e.g., OSCORE parameters) received from - the AS to the RS. The RS then generates a nonce N2, and uses - Section 3.2 of [RFC8613] to derive a security context based on a - shared master secret and the two nonces, established between client - and server. The nonces are encoded as bstr if CBOR is used, and as - Base64 string if JSON is used. This security context is used to - protect all future communication between client and RS using OSCORE, - as long as the access token is valid. + client generates a nonce N1 and an identifier ID1 unique in the sets + of its own Recipient IDs, and posts them together with the token that + includes the materials (e.g., OSCORE parameters) received from the AS + to the RS. The RS then generates a nonce N2 and an identifier ID2 + unique in the sets of its own Recipient IDs, and uses Section 3.2 of + [RFC8613] to derive a security context based on a shared master + secret, the two nonces and the two identifiers, established between + client and server. The nonces and identifiers are encoded as CBOR + byte string if CBOR is used, and as Base64 string if JSON is used. + This security context is used to protect all future communication + between client and RS using OSCORE, as long as the access token is + valid. Note that the RS and client authenticates themselves by generating the shared OSCORE Security Context using the pop-key as master secret. An attacker posting a valid token to the RS will not be able to generate a valid OSCORE context and thus not be able to prove possession of the pop-key. Additionally, the mutual authentication is only achieved after the client has successfully verified the response from the RS. 4.1. C-to-RS: POST to authz-info endpoint The client MUST generate a nonce value very unlikely to have been previously used with the same input keying material. This profile RECOMMENDS to use a 64-bit long random number as nonce's value. The client MUST store the nonce N1 as long as the response from the RS is - not received and the access token related to it is still valid. The - client MUST use CoAP and the Authorization Information resource as - described in section 5.8.1 of [I-D.ietf-ace-oauth-authz] to transport - the token and N1 to the RS. + not received and the access token related to it is still valid. + + The client generates its own Recipient ID, ID1, for the OSCORE + Security Context that it is establishing with the RS. By generating + its own Recipient ID, the client makes sure that it does not collide + with any of its Recipient IDs. + + The client MUST use CoAP and the Authorization Information resource + as described in section 5.8.1 of [I-D.ietf-ace-oauth-authz] to + transport the token, N1 and ID1 to the RS. Note that the use of the payload and the Content-Format is different from what is described in section 5.8.1 of [I-D.ietf-ace-oauth-authz], which only transports the token without any CBOR wrapping. In this profile, the client MUST wrap the token and N1 in a CBOR map. The client MUST use the Content-Format "application/ace+cbor" defined in section 8.14 of [I-D.ietf-ace-oauth-authz]. The client MUST include the access token - using the "access_token" parameter and N1 using the 'nonce1' - parameter defined in Section 4.1.1. + using the "access_token" parameter, N1 using the 'nonce1' parameter + defined in Section 4.1.1, and ID1 using the 'ace_client_recipientid' + parameter defined in Section 4.1.2. The communication with the authz-info endpoint does not have to be protected, except for the update of access rights case described below. Note that a client may be required to re-POST the access token in order to complete a request, since an RS may delete a stored access token (and associated Security Context) at any time, for example due to all storage space being consumed. This situation is detected by the client when it receives an AS Request Creation Hints response. Reposting the same access token will result in deriving a new OSCORE Security Context to be used with the RS, as different nonces will be used. - Figure 11 shows an example of the request sent from the client to the + Figure 10 shows an example of the request sent from the client to the RS, with payload in CBOR diagnostic notation without the tag and value abbreviations. The access token has been truncated for readability. Header: POST (Code=0.02) Uri-Host: "rs.example.com" Uri-Path: "authz-info" Content-Format: "application/ace+cbor" Payload: { "access_token": h'8343a1010aa2044c53 ... (remainder of access token (CWT) omitted for brevity)', - "nonce1": h'018a278f7faab55a' + "nonce1": h'018a278f7faab55a', + "ace_client_recipientid" : h'1645' } - Figure 11: Example C-to-RS POST /authz-info request using CWT + Figure 10: Example C-to-RS POST /authz-info request using CWT If the client has already posted a valid token, has already established a security association with the RS, and wants to update its access rights, the client can do so by posting the new token (retrieved from the AS and containing the update of access rights) to the /authz-info endpoint. The client MUST protect the request using the OSCORE Security Context established during the first token exchange. The client MUST only send the access token in the payload, - no nonce is sent. After proper verification (see Section 4.2), the - RS will replace the old token with the new one, maintaining the same - Security Context. + no nonce or identifier are sent. After proper verification (see + Section 4.2), the RS will replace the old token with the new one, + maintaining the same Security Context. 4.1.1. The Nonce 1 Parameter This parameter MUST be sent from the client to the RS, together with the access token, if the ace profile used is coap_oscore. The parameter is encoded as a byte string for CBOR-based interactions, and as a string (Base64 encoded binary) for JSON-based interactions. This parameter is registered in Section 9.2. +4.1.2. The ace_client_recipientid Parameter + + This parameter MUST be sent from the client to the RS, together with + the access token, if the ace profile used is coap_oscore. The + parameter is encoded as a byte string for CBOR-based interactions, + and as a string (Base64 encoded binary) for JSON-based interactions. + This parameter is registered in Section 9.2. + 4.2. RS-to-C: 2.01 (Created) The RS MUST follow the procedures defined in section 5.8.1 of [I-D.ietf-ace-oauth-authz]: the RS must verify the validity of the token. If the token is valid, the RS must respond to the POST request with 2.01 (Created). If the token is valid but is associated to claims that the RS cannot process (e.g., an unknown scope), or if - any of the expected parameters in the 'osc' is missing (e.g., any of - the mandatory parameters from the AS), or if any parameters received - in the 'osc' is unrecognized, the RS must respond with an error - response code equivalent to the CoAP code 4.00 (Bad Request). In the - latter two cases, the RS may provide additional information in the - error response, in order to clarify what went wrong. The RS may make - an introspection request (see Section 5.7.1 of + any of the expected parameters is missing (e.g., any of the mandatory + parameters from the AS or the identifier), or if any parameters + received in the 'osc' is unrecognized, the RS must respond with an + error response code equivalent to the CoAP code 4.00 (Bad Request). + In the latter two cases, the RS may provide additional information in + the error response, in order to clarify what went wrong. The RS may + make an introspection request (see Section 5.7.1 of [I-D.ietf-ace-oauth-authz]) to validate the token before responding to the POST request to the authz-info endpoint. Additionally, the RS MUST generate a nonce N2 very unlikely to have - been previously used with the same input keying material, and send it - within the 2.01 (Created) response. The payload of the 2.01 - (Created) response MUST be a CBOR map containing the 'nonce2' - parameter defined in Section 4.2.1, set to N2. This profile - RECOMMENDS to use a 64-bit long random number as nonce's value. The - RS MUST use the Content-Format "application/ace+cbor" defined in - section 8.14 of [I-D.ietf-ace-oauth-authz]. + been previously used with the same input keying material, and its own + Recipient ID, ID2. The RS makes sure that ID2 does not collide with + any of its Recipient IDs. The RS MUST ensure that ID2 is different + from the ace_client_recipientid. The RS sends N2 and ID2 within the + 2.01 (Created) response. The payload of the 2.01 (Created) response + MUST be a CBOR map containing the 'nonce2' parameter defined in + Section 4.2.1, set to N2, and the 'ace_server_recipientid' parameter + defined in Section 4.2.2, set to ID2. This profile RECOMMENDS to use + a 64-bit long random number as nonce's value. The RS MUST use the + Content-Format "application/ace+cbor" defined in section 8.14 of + [I-D.ietf-ace-oauth-authz]. - Figure 12 shows an example of the response sent from the RS to the + Figure 11 shows an example of the response sent from the RS to the client, with payload in CBOR diagnostic notation without the tag and value abbreviations. Header: Created (Code=2.01) Content-Format: "application/ace+cbor" Payload: { - "nonce2": h'25a8991cd700ac01' + "nonce2": h'25a8991cd700ac01', + "ace_server_recipientid" : h'0000' } - Figure 12: Example RS-to-C 2.01 (Created) response + Figure 11: Example RS-to-C 2.01 (Created) response As specified in section 5.8.3 of [I-D.ietf-ace-oauth-authz], the RS must notify the client with an error response with code 4.01 (Unauthorized) for any long running request before terminating the session, when the access token expires. If the RS receives the token in a OSCORE protected message, it means that the client is requesting an update of access rights. The RS - MUST discard any nonce in the request, if any was sent. The RS MUST - check that the "kid" of the "cnf" parameter of the new access token - matches the OSCORE Security Context used to protect the message. If - that is the case, the RS MUST discard the old token and associate the - new token to the Security Context identified by the "kid" value in - the "cnf" parameter. The RS MUST respond with a 2.01 (Created) - response protected with the same Security Context, with no payload. - - If any verification fails, the RS MUST respond with a 4.01 - (Unauthorized) error response. + MUST discard any nonce and identifiers in the request, if any was + sent. The RS MUST check that the "kid" of the "cnf" parameter of the + new access token matches the OSCORE Input Material of the context + used to protect the message. If that is the case, the RS MUST + discard the old token and associate the new token to the Security + Context identified by the "kid" value in the "cnf" parameter. The RS + MUST respond with a 2.01 (Created) response protected with the same + Security Context, with no payload. If any verification fails, the RS + MUST respond with a 4.01 (Unauthorized) error response. As specified in section 5.8.1 of [I-D.ietf-ace-oauth-authz], when receiving an updated access token with updated authorization information from the client (see Section 3.1), it is recommended that the RS overwrites the previous token, that is only the latest authorization information in the token received by the RS is valid. This simplifies the process needed by the RS to keep track of authorization information for a given client. 4.2.1. The Nonce 2 Parameter - This parameter MUST be sent from the RS to the Client if the ace + This parameter MUST be sent from the RS to the client if the ace profile used is coap_oscore. The parameter is encoded as a byte string for CBOR-based interactions, and as a string (Base64 encoded binary) for JSON-based interactions. This parameter is registered in - Section 9.2. + Section 9.2 + +4.2.2. The ace_server_recipientid Parameter + + This parameter MUST be sent from the RS to the client if the ace + profile used is coap_oscore. The parameter is encoded as a byte + string for CBOR-based interactions, and as a string (Base64 encoded + binary) for JSON-based interactions. This parameter is registered in + Section 9.2 4.3. OSCORE Setup Once receiving the 2.01 (Created) response from the RS, following the POST request to authz-info endpoint, the client MUST extract the bstr nonce N2 from the 'nonce2' parameter in the CBOR map in the payload of the response. Then, the client MUST set the Master Salt of the Security Context created to communicate with the RS to the concatenation of salt, N1, and N2, in this order: Master Salt = salt | N1 | N2, where | denotes byte string concatenation, where salt is the CBOR byte string received from the AS in Section 3.2, and where N1 and N2 are the two nonces encoded as CBOR byte strings. An example of Master Salt construction using CBOR encoding is given in - Figure 13. + Figure 12. N1, N2 and input salt expressed in CBOR diagnostic notation: nonce1 = h'018a278f7faab55a' nonce2 = h'25a8991cd700ac01' input salt = h'f9af838368e353e78888e1426bd94e6f' N1, N2 and input salt as CBOR encoded byte strings: nonce1 = 0x48018a278f7faab55a nonce2 = 0x4825a8991cd700ac01 input salt = 0x50f9af838368e353e78888e1426bd94e6f Master Salt = 0x50 f9af838368e353e78888e1426bd94e6f 48 018a278f7faab55a 48 25a8991cd700ac01 - Figure 13: Example of Master Salt construction using CBOR encoding + Figure 12: Example of Master Salt construction using CBOR encoding If JSON is used instead of CBOR, the Master Salt of the Security Context is the Base64 encoding of the concatenation of the same parameters, each of them prefixed by their size, encoded in 1 byte. When using JSON, the nonces and input salt have a maximum size of 255 bytes. An example of Master Salt construction using Base64 encoding - is given in Figure 14. + is given in Figure 13. N1, N2 and input salt values: nonce1 = 0x018a278f7faab55a (8 bytes) nonce2 = 0x25a8991cd700ac01 (8 bytes) input salt = 0xf9af838368e353e78888e1426bd94e6f (16 bytes) Input to Base64 encoding: 0x10 f9af838368e353e78888e1426bd94e6f 08 018a278f7faab55a 08 25a8991cd700ac01 Master Salt = b64'EPmvg4No41PniIjhQmvZTm8IAYonj3+qtVoIJaiZHNcArAE=' - Figure 14: Example of Master Salt construction using Base64 encoding + Figure 13: Example of Master Salt construction using Base64 encoding - The client MUST set the Master Secret, Sender ID and Recipient ID - from the parameters received from the AS in Section 3.2. The client - MUST set the AEAD Algorithm, ID Context, HKDF, and OSCORE Version - from the parameters received from the AS in Section 3.2, if present. - In case an optional parameter is omitted, the default value SHALL be - used as described in sections 3.2 and 5.4 of [RFC8613]. After that, - the client MUST derive the complete Security Context following - section 3.2.1 of [RFC8613]. From this point on, the client MUST use - this Security Context to communicate with the RS when accessing the - resources as specified by the authorization information. + The client MUST set the Sender ID to the ace_server_recipientid + received in Section 4.2, and the Recipient ID to the + ace_client_recipientid sent in Section 4.1. The client MUST set the + Master Secret from the parameter received from the AS in Section 3.2. + The client MUST set the AEAD Algorithm, ID Context, HKDF, and OSCORE + Version from the parameters received from the AS in Section 3.2, if + present. In case an optional parameter is omitted, the default value + SHALL be used as described in sections 3.2 and 5.4 of [RFC8613]. + After that, the client MUST derive the complete Security Context + following section 3.2.1 of [RFC8613]. From this point on, the client + MUST use this Security Context to communicate with the RS when + accessing the resources as specified by the authorization + information. If any of the expected parameters is missing (e.g., any of the - mandatory parameters from the AS, the client MUST stop the exchange, - and MUST NOT derive the Security Context. The client MAY restart the - exchange, to get the correct security material. + mandatory parameters from the AS or the RS), or if + ace_client_recipientid equals ace_server_recipientid, then the client + MUST stop the exchange, and MUST NOT derive the Security Context. + The client MAY restart the exchange, to get the correct security + material. The client then uses this Security Context to send requests to RS using OSCORE. After sending the 2.01 (Created) response, the RS MUST set the Master Salt of the Security Context created to communicate with the client to the concatenation of salt, N1, and N2, in the same way described above. An example of Master Salt construction using CBOR encoding is - given in Figure 13 and using Base64 encoding is given in Figure 14. - The RS MUST set the Master Secret, Sender ID and Recipient ID from - the parameters, received from the AS and forwarded by the client in - the access token in Section 4.1 after validation of the token as - specified in Section 4.2. The RS MUST set the AEAD Algorithm, ID - Context, HKDF, and OSCORE Version from the parameters received from - the AS and forwarded by the client in the access token in Section 4.1 - after validation of the token as specified in Section 4.2, if - present. In case an optional parameter is omitted, the default value - SHALL be used as described in sections 3.2 and 5.4 of [RFC8613]. - After that, the RS MUST derive the complete Security Context - following section 3.2.1 of [RFC8613], and MUST associate this + given in Figure 12 and using Base64 encoding is given in Figure 13. + The RS MUST set the Sender ID from the ace_client_recipientid + received in Section 4.1, and the Recipient ID from the + ace_server_recipientid sent in Section 4.2. The RS MUST set the + Master Secret from the parameter, received from the AS and forwarded + by the client in the access token in Section 4.1 after validation of + the token as specified in Section 4.2. The RS MUST set the AEAD + Algorithm, ID Context, HKDF, and OSCORE Version from the parameters + received from the AS and forwarded by the client in the access token + in Section 4.1 after validation of the token as specified in + Section 4.2, if present. In case an optional parameter is omitted, + the default value SHALL be used as described in sections 3.2 and 5.4 + of [RFC8613]. After that, the RS MUST derive the complete Security + Context following section 3.2.1 of [RFC8613], and MUST associate this Security Context with the authorization information from the access token. The RS then uses this Security Context to verify requests and send responses to C using OSCORE. If OSCORE verification fails, error responses are used, as specified in section 8 of [RFC8613]. Additionally, if OSCORE verification succeeds, the verification of access rights is performed as described in section Section 4.4. The RS MUST NOT use the Security Context after the related token has expired, and MUST respond with a unprotected 4.01 (Unauthorized) error message to requests received that correspond to a Security Context with an expired token. Note that the ID Context can be assigned by the AS, communicated and set in both the RS and client after the exchange specified in this profile is executed. Subsequently, client and RS can update their ID Context by running a mechanism such as the one defined in - Appendix B.2 of [RFC8613] if they support it. In that case, the ID - Context in the OSCORE Security Context will not match the "contextId" - parameter of the corresponding OSCORE_Input_Material. That is fine, - as long as the nodes store and use the "contextId" value to identify - the correct OSCORE_Input_Material at the AS. + Appendix B.2 of [RFC8613] if they both support it and are configured + to do so. In that case, the ID Context in the OSCORE Security + Context will not match the "contextId" parameter of the corresponding + OSCORE_Input_Material. Running Appendix B.2 results in the keying + material in the Security Contexts of client and RS being updated; + this same result can also be achieved by the client reposting the + access token as described in Section 4.1, but without updating the ID + Context. 4.4. Access rights verification The RS MUST follow the procedures defined in section 5.8.2 of [I-D.ietf-ace-oauth-authz]: if an RS receives an OSCORE-protected request from a client, then the RS processes it according to [RFC8613]. If OSCORE verification succeeds, and the target resource requires authorization, the RS retrieves the authorization information using the access token associated to the Security Context. The RS then must verify that the authorization information @@ -1067,21 +1051,21 @@ Authorization for Constrained Environments (ACE) framework [I-D.ietf-ace-oauth-authz]. Thus the general security considerations from the framework also apply to this profile. Furthermore the general security considerations of OSCORE [RFC8613] also apply to this specific use of the OSCORE protocol. As previously stated, the proof-of-possession in this profile is performed by both parties verifying that they have established the same Security Context, as specified in Section 4.3, which means that - both the OSCORE request and OSCORE pass verification. RS + both the OSCORE request and OSCORE response pass verification. RS authentication requires both that the client trusts the AS and that the OSCORE response from the RS pass verification. OSCORE is designed to secure point-to-point communication, providing a secure binding between the request and the response(s). Thus the basic OSCORE protocol is not intended for use in point-to-multipoint communication (e.g., multicast, publish-subscribe). Implementers of this profile should make sure that their usecase corresponds to the expected use of OSCORE, to prevent weakening the security assurances provided by OSCORE. @@ -1141,24 +1124,24 @@ The token is sent in the clear to the authz-info endpoint, so if a client uses the same single token from multiple locations with multiple Resource Servers, it can risk being tracked by the token's value even when the access token is encrypted. The nonces exchanged in the request and response to the authz-info endpoint are also sent in the clear, so using random nonces is best for privacy (as opposed to, e.g., a counter, that might leak some information about the client). - The AS is the party tasked with assigning the identifiers used in - OSCORE, which are privacy sensitive (see Section 12.8 of [RFC8613]), - and which could reveal information about the client, or may be used - for correlating requests from one client. + The identifiers used in OSCORE, negotiated between client and RS are + privacy sensitive (see Section 12.8 of [RFC8613]), and could reveal + information about the client, or may be used for correlating requests + from one client. Note that some information might still leak after OSCORE is established, due to observable message sizes, the source, and the destination addresses. 9. IANA Considerations Note to RFC Editor: Please replace all occurrences of "[[this specification]]" with the RFC number of this specification and delete this paragraph. @@ -1185,35 +1168,54 @@ o Parameter name: nonce1 o Parameter usage location: client-rs request o Change Controller: IESG o Specification Document(s): [[this specification]] o Parameter name: nonce2 o Parameter usage location: rs-client response o Change Controller: IESG o Specification Document(s): [[this specification]] + o Parameter name: ace_client_recipientid + o Parameter usage location: client-rs request + o Change Controller: IESG + o Specification Document(s): [[this specification]] + + o Parameter name: ace_server_recipientid + o Parameter usage location: rs-client response + o Change Controller: IESG + o Specification Document(s): [[this specification]] + 9.3. OAuth Parameters CBOR Mappings Registry The following registrations are done for the OAuth Parameters CBOR Mappings Registry following the procedure specified in section 8.10 of [I-D.ietf-ace-oauth-authz]: o Name: nonce1 o CBOR Key: TBD1 o Value Type: bstr o Reference: [[this specification]] o Name: nonce2 o CBOR Key: TBD2 o Value Type: bstr o Reference: [[this specification]] + o Name: ace_client_recipientid + o CBOR Key: TBD3 + o Value Type: bstr + o Reference: [[this specification]] + + o Name: ace_server_recipientid + o CBOR Key: TBD4 + o Value Type: bstr + o Reference: [[this specification]] 9.4. OSCORE Security Context Parameters Registry It is requested that IANA create a new registry entitled "OSCORE Security Context Parameters" registry. The registry is to be created as Expert Review Required. Guidelines for the experts is provided Section 9.7. It should be noted that in addition to the expert review, some portions of the registry require a specification, potentially on standards track, be supplied as well. @@ -1325,22 +1327,22 @@ Framework (ACE-OAuth)", draft-ietf-ace-oauth-authz-35 (work in progress), June 2020. [I-D.ietf-ace-oauth-params] Seitz, L., "Additional OAuth Parameters for Authorization in Constrained Environments (ACE)", draft-ietf-ace-oauth- params-13 (work in progress), April 2020. [I-D.ietf-cbor-7049bis] Bormann, C. and P. Hoffman, "Concise Binary Object - Representation (CBOR)", draft-ietf-cbor-7049bis-14 (work - in progress), June 2020. + Representation (CBOR)", draft-ietf-cbor-7049bis-16 (work + in progress), September 2020. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained Application Protocol (CoAP)", RFC 7252, DOI 10.17487/RFC7252, June 2014, .