--- 1/draft-ietf-ace-dtls-authorize-03.txt 2018-09-06 02:13:09.274435108 -0700 +++ 2/draft-ietf-ace-dtls-authorize-04.txt 2018-09-06 02:13:09.326436362 -0700 @@ -1,24 +1,24 @@ ACE Working Group S. Gerdes Internet-Draft O. Bergmann Intended status: Standards Track C. Bormann -Expires: September 6, 2018 Universitaet Bremen TZI +Expires: March 10, 2019 Universitaet Bremen TZI G. Selander Ericsson L. Seitz RISE SICS - March 05, 2018 + September 06, 2018 Datagram Transport Layer Security (DTLS) Profile for Authentication and Authorization for Constrained Environments (ACE) - draft-ietf-ace-dtls-authorize-03 + draft-ietf-ace-dtls-authorize-04 Abstract This specification defines a profile for delegating client authentication and authorization in a constrained environment by establishing a Datagram Transport Layer Security (DTLS) channel between resource-constrained nodes. The protocol relies on DTLS for communication security between entities in a constrained network using either raw public keys or pre-shared keys. A resource- constrained node can use this protocol to delegate management of @@ -33,21 +33,21 @@ 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 September 6, 2018. + This Internet-Draft will expire on March 10, 2019. Copyright Notice Copyright (c) 2018 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 @@ -61,24 +61,24 @@ 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 3 2.1. Resource Access . . . . . . . . . . . . . . . . . . . . . 5 2.2. Dynamic Update of Authorization Information . . . . . . . 7 2.3. Token Expiration . . . . . . . . . . . . . . . . . . . . 8 3. RawPublicKey Mode . . . . . . . . . . . . . . . . . . . . . . 9 4. PreSharedKey Mode . . . . . . . . . . . . . . . . . . . . . . 10 4.1. DTLS Channel Setup Between C and RS . . . . . . . . . . . 12 - 4.2. Updating Authorization Information . . . . . . . . . . . 14 + 4.2. Updating Authorization Information . . . . . . . . . . . 13 5. Security Considerations . . . . . . . . . . . . . . . . . . . 14 6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 14 - 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 + 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1. Normative References . . . . . . . . . . . . . . . . . . 15 8.2. Informative References . . . . . . . . . . . . . . . . . 16 8.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 1. Introduction This specification defines a profile of the ACE framework [I-D.ietf-ace-oauth-authz]. In this profile, a client and a resource @@ -96,26 +96,20 @@ provide proof-of-possession for the key tied to the access token. Here the access token needs to be transferred to the resource server before the handshake is initiated, as described in section 5.8.1 of draft-ietf-ace-oauth-authz [1]. The DTLS PSK handshake [RFC4279] provides the proof-of-possession for the key tied to the access token. Furthermore the psk_identity parameter in the DTLS PSK handshake is used to transfer the access token from the client to the resource server. - Note: While the scope of this draft is on client and resource server - - communicating using CoAP over DTLS, it is expected that it applies - also to CoAP over TLS, possibly with minor modifications. - However, that is out of scope for this version of the draft. - 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. Readers are expected to be familiar with the terms and concepts described in [I-D.ietf-ace-oauth-authz]. @@ -143,55 +137,59 @@ | --- Token Request ----------------------------> | | | | | <---------------------------- Access Token ----- | | + RS Information | Figure 1: Retrieving an Access Token To determine the AS in charge of a resource hosted at the RS, the client C MAY send an initial Unauthorized Resource Request message to the RS. The RS then denies the request and sends the address of its - AS back to the client C. + AS back to the client C as specified in section 5.1.2 of draft-ietf- + ace-oauth-authz [2]. Once the client C knows the authorization server's address, it can send an Access Token request to the token endpoint at the AS as specified in [I-D.ietf-ace-oauth-authz]. As the Access Token request as well as the response may contain confidential data, the communication between the client and the authorization server MUST be confidentiality-protected and ensure authenticity. How the mutual authentication between the client and the authorization server is achieved is out of scope for this document; the client may have been configured with a public key of the authorization server and have been registered at the AS via the OAuth client registration mechanism - as outlined in section 5.3 of draft-ietf-ace-oauth-authz [2]. + as outlined in section 5.3 of draft-ietf-ace-oauth-authz [3]. If C wants to use the CoAP RawPublicKey mode as described in - Section 9 of RFC 7252 [3] it MUST provide a key or key identifier + Section 9 of RFC 7252 [4] it MUST provide a key or key identifier within a "cnf" object in the token request. If the authorization server AS decides that the request is to be authorized it generates an access token response for the client C containing a "profile" parameter with the value "coap_dtls" to indicate that this profile MUST be used for communication between the client C and the resource - server. Is also adds a "cnf" parameter with additional data for the - establishment of a secure DTLS channel between the client and the - resource server. The semantics of the 'cnf' parameter depend on the - type of key used between the client and the resource server and - control whether the client must use RPK mode or PSK mode to establish - a DTLS session with the resource server, see Section 3 and Section 4. + server. + + For RPK mode, the authorization server also adds a "rs_cnf" parameter + containing information about the public that is used by the resource + server (see Section 3). + + For PSK mode, the authorization server adds a "cnf" parameter + containing information about the shared secret that C can use to + setup a DTLS session with the resource server (see Section 4). The Access Token returned by the authorization server then can be used by the client to establish a new DTLS session with the resource server. When the client intends to use asymmetric cryptography in the DTLS handshake with the resource server, the client MUST upload the Access Token to the authz-info resource on the resource server before starting the DTLS handshake, as described in section 5.8.1 of - draft-ietf-ace-oauth-authz [4]. If only symmetric cryptography is + draft-ietf-ace-oauth-authz [5]. If only symmetric cryptography is used between the client and the resource server, the Access Token MAY instead be transferred in the DTLS ClientKeyExchange message (see Section 4.1). Figure 2 depicts the common protocol flow for the DTLS profile after the client C has retrieved the Access Token from the authorization server AS. C RS AS | [--- Access Token ------>] | | @@ -225,27 +223,27 @@ info resource hosted by the resource server. On the resource server side, successful establishment of the DTLS channel binds the client to the access token, functioning as a proof- of-possession associated key. Any request that the resource server receives on this channel MUST be checked against these authorization rules that are associated with the identity of the client. Incoming CoAP requests that are not authorized with respect to any Access Token that is associated with the client MUST be rejected by the resource server with 4.01 response as described in Section 5.1.1 of - draft-ietf-ace-oauth-authz [5]. + draft-ietf-ace-oauth-authz [6]. Note: The identity of the client is determined by the authentication process during the DTLS handshake. In the asymmetric case, the public key will define the client's identity, while in the PSK case, the - client's identity is defined by the session key generated by the + client's identity is defined by the shared secret generated by the authorization server for this communication. The resource server SHOULD treat an incoming CoAP request as authorized if the following holds: 1. The message was received on a secure channel that has been established using the procedure defined in this document. 2. The authorization information tied to the sending peer is valid. @@ -253,34 +251,34 @@ 4. The resource URI specified in the request is covered by the authorization information. 5. The request method is an authorized action on the resource with respect to the authorization information. Incoming CoAP requests received on a secure DTLS channel MUST be rejected according to [Section 5.1.1 of draft-ietf-ace-oauth- authz](https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.1.1 + 13#section-5.1.1 1. with response code 4.03 (Forbidden) when the resource URI specified in the request is not covered by the authorization information, and 2. with response code 4.05 (Method Not Allowed) when the resource URI specified in the request covered by the authorization information but not the requested action. The client cannot always know a priori if an Authorized Resource Request will succeed. If the client repeatedly gets error responses containing AS Information (cf. Section 5.1.1 of draft-ietf-ace- - oauth-authz [6] as response to its requests, it SHOULD request a new + oauth-authz [7] as response to its requests, it SHOULD request a new Access Token from the authorization server in order to continue communication with the resource server. 2.2. Dynamic Update of Authorization Information The client can update the authorization information stored at the resource server at any time without changing an established DTLS session. To do so, the Client requests from the authorization server a new Access Token for the intended action on the respective resource and uploads this Access Token to the authz-info resource on the @@ -289,21 +287,21 @@ Figure 3 depicts the message flow where the client C requests a new Access Token after a security association between the client and the resource server RS has been established using this protocol. The token request MUST specify the key identifier of the existing DTLS channel between the client and the resource server in the "kid" parameter of the Client-to-AS request. The authorization server MUST verify that the specified "kid" denotes a valid verifier for a proof- of-possession ticket that has previously been issued to the requesting client. Otherwise, the Client-to-AS request MUST be declined with a the error code "unsupported_pop_key" as defined in - Section 5.6.3 of draft-ietf-ace-oauth-authz [7]. + Section 5.6.3 of draft-ietf-ace-oauth-authz [8]. When the authorization server issues a new access token to update existing authorization information it MUST include the specified "kid" parameter in this access token. A resource server MUST associate the updated authorization information with any existing DTLS session that is identified by this key identifier. Note: By associating the access tokens with the identifier of an existing DTLS session, the authorization information can be updated without changing the cryptographic keys for the DTLS @@ -331,41 +329,41 @@ 2.3. Token Expiration DTLS sessions that have been established in accordance with this profile are always tied to a specific set of access tokens. As these tokens may become invalid at any time (either because the token has expired or the responsible authorization server has revoked the token), the session may become useless at some point. A resource server therefore may decide to terminate existing DTLS sessions after the last valid access token for this session has been deleted. - As specified in section 5.8.2 of draft-ietf-ace-oauth-authz [8], the + As specified in section 5.8.3 of draft-ietf-ace-oauth-authz [9], the resource server MUST notify the client with an error response with code 4.01 (Unauthorized) for any long running request before terminating the session. The resource server MAY also keep the session alive for some time and respond to incoming requests with a 4.01 (Unauthorized) error message including AS Information to signal that the client needs to upload a new access token before it can continue using this DTLS session. The AS Information is created as specified in section 5.1.2 of draft- - ietf-ace-oauth-authz [9]. The resource server SHOULD add a "kid" + ietf-ace-oauth-authz [10]. The resource server SHOULD add a "kid" parameter to the AS Information denoting the identifier of the key that it uses internally for this DTLS session. The client then includes this "kid" parameter in a Client-to-AS request used to retrieve a new access token to be used with this DTLS session. In case the key identifier is already known by the client (e.g. because it was included in the RS Information in an AS-to-Client response), the "kid" parameter MAY be elided from the AS Information. Table 1 updates Figure 2 in section 5.1.2 of draft-ietf-ace-oauth- - authz [10] with the new "kid" parameter in accordance with [RFC8152]. + authz [11] with the new "kid" parameter in accordance with [RFC8152]. +----------------+----------+-----------------+ | Parameter name | CBOR Key | Major Type | +----------------+----------+-----------------+ | kid | 4 | 2 (byte string) | +----------------+----------+-----------------+ Table 1: Updated AS Information parameters 3. RawPublicKey Mode @@ -409,99 +407,95 @@ MUST send a "POST" request containing the new Access Token to the authz-info resource hosted by the resource server. If this operation yields a positive response, the client SHOULD proceed to establish a new DTLS channel with the resource server. To use raw public key mode, the client MUST pass the same public key that was used for constructing the Access Token with the SubjectPublicKeyInfo structure in the DTLS handshake as specified in [RFC7250]. An implementation that supports the RPK mode of this profile MUST at least support the ciphersuite TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 - [RFC7251] with the ed25519 curve (cf. [RFC8032], - [I-D.ietf-tls-rfc4492bis]). + [RFC7251] with the ed25519 curve (cf. [RFC8032], [RFC8422]). Note: According to [RFC7252], CoAP implementations MUST support the ciphersuite TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 [RFC7251] and the NIST P-256 curve. As discussed in [RFC7748], new ECC curves have been defined recently that are considered superior to the so- called NIST curves. The curve that is mandatory to implement in this specification is said to be efficient and less dangerous regarding implementation errors than the secp256r1 curve mandated in [RFC7252]. The Access Token is constructed by the authorization server such that the resource server can associate the Access Token with the Client's - public key. If CBOR web tokens [I-D.ietf-ace-cbor-web-token] are - used as recommended in [I-D.ietf-ace-oauth-authz], the authorization - server MUST include a "COSE_Key" object in the "cnf" claim of the - Access Token. This "COSE_Key" object MAY contain a reference to a - key for the client that is already known by the resource server - (e.g., from previous communication). If the authorization server has - no certain knowledge that the Client's key is already known to the - resource server, the Client's public key MUST be included in the - Access Token's "cnf" parameter. + public key. If CBOR web tokens [RFC8392] are used as recommended in + [I-D.ietf-ace-oauth-authz], the authorization server MUST include a + "COSE_Key" object in the "cnf" claim of the Access Token. This + "COSE_Key" object MAY contain a reference to a key for the client + that is already known by the resource server (e.g., from previous + communication). If the authorization server has no certain knowledge + that the Client's key is already known to the resource server, the + Client's public key MUST be included in the Access Token's "cnf" + parameter. 4. PreSharedKey Mode To retrieve an access token for the resource that the client wants to access, the client MAY include a "cnf" object carrying an identifier for a symmetric key in its Access Token request to the authorization server. This identifier can be used by the authorization server to - determine the session key to construct the proof-of-possession token - and therefore MUST specify a symmetric key that was previously - generated by the authorization server as a session key for the + determine the shared secret to construct the proof-of-possession + token and therefore MUST specify a symmetric key that was previously + generated by the authorization server as a shared secret for the communication between the client and the resource server. Depending on the requested token type and algorithm in the Access Token request, the authorization server adds RS Information to the response that provides the client with sufficient information to setup a DTLS channel with the resource server. For symmetric proof- of-possession keys (c.f. [I-D.ietf-ace-oauth-authz]), the client must ensure that the Access Token request is sent over a secure channel that guarantees authentication, message integrity and confidentiality. When the authorization server authorizes the client it returns an AS- to-Client response with the profile parameter set to "coap_dtls" and a "cnf" parameter carrying a "COSE_Key" object that contains the - symmetric session key to be used between the client and the resource - server as illustrated in Figure 5. + symmetric key to be used between the client and the resource server + as illustrated in Figure 5. 2.01 Created Content-Format: application/cbor Location-Path: /token/asdjbaskd - Max-Age: 86400 { access_token: h'd08343a10... (remainder of CWT omitted for brevity) token_type: pop, alg: HS256, expires_in: 86400, profile: coap_dtls, cnf: { COSE_Key: { kty: symmetric, k: h'73657373696f6e6b6579' } } } Figure 5: Example Access Token response In this example, the authorization server returns a 2.01 response containing a new Access Token. The information is transferred as a - CBOR data structure as specified in [I-D.ietf-ace-oauth-authz]. The - Max-Age option tells the receiving Client how long this token will be - valid. + CBOR data structure as specified in [I-D.ietf-ace-oauth-authz]. A response that declines any operation on the requested resource is - constructed according to Section 5.2 of RFC 6749 [11], (cf. + constructed according to Section 5.2 of RFC 6749 [12], (cf. Section 5.7.3 of [I-D.ietf-ace-oauth-authz]). 4.00 Bad Request Content-Format: application/cbor { error: invalid_request } Figure 6: Example Access Token response with reject @@ -509,31 +503,31 @@ When a client receives an Access Token from an authorization server, it checks if the payload contains an "access_token" parameter and a "cnf" parameter. With this information the client can initiate establishment of a new DTLS channel with a resource server. To use DTLS with pre-shared keys, the client follows the PSK key exchange algorithm specified in Section 2 of [RFC4279] using the key conveyed in the "cnf" parameter of the AS response as PSK when constructing the premaster secret. - In PreSharedKey mode, the knowledge of the session key by the client - and the resource server is used for mutual authentication between - both peers. Therefore, the resource server must be able to determine - the session key from the Access Token. Following the general ACE - authorization framework, the client can upload the Access Token to - the resource server's authz-info resource before starting the DTLS - handshake. Alternatively, the client MAY provide the most recent - Access Token in the "psk_identity" field of the ClientKeyExchange - message. To do so, the client MUST treat the contents of the - "access_token" field from the AS-to-Client response as opaque data - and not perform any re-coding. + In PreSharedKey mode, the knowledge of the shared secret by the + client and the resource server is used for mutual authentication + between both peers. Therefore, the resource server must be able to + determine the shared secret from the Access Token. Following the + general ACE authorization framework, the client can upload the Access + Token to the resource server's authz-info resource before starting + the DTLS handshake. Alternatively, the client MAY provide the most + recent Access Token in the "psk_identity" field of the + ClientKeyExchange message. To do so, the client MUST treat the + contents of the "access_token" field from the AS-to-Client response + as opaque data and not perform any re-coding. Note: As stated in section 4.2 of [RFC7925], the PSK identity should be treated as binary data in the Internet of Things space and not assumed to have a human-readable form of any sort. If a resource server receives a ClientKeyExchange message that contains a "psk_identity" with a length greater zero, it uses the contents as index for its key store (i.e., treat the contents as key identifier). The resource server MUST check if it has one or more Access Tokens that are associated with the specified key. If no @@ -555,62 +549,56 @@ SHOULD NOT send a ServerKeyExchange message. Note2: According to [RFC7252], CoAP implementations MUST support the ciphersuite TLS_PSK_WITH_AES_128_CCM_8 [RFC6655]. A client is therefore expected to offer at least this ciphersuite to the resource server. This specification assumes that the Access Token is a PoP token as described in [I-D.ietf-ace-oauth-authz] unless specifically stated otherwise. Therefore, the Access Token is bound to a symmetric PoP - key that is used as session key between the client and the resource + key that is used as shared secret between the client and the resource server. - While the client can retrieve the session key from the contents of + While the client can retrieve the shared secret from the contents of the "cnf" parameter in the AS-to-Client response, the resource server uses the information contained in the "cnf" claim of the Access Token - to determine the actual session key when no explicit "kid" was - provided in the "psk_identity" field. Usually, this is done by - including a "COSE_Key" object carrying either a key that has been - encrypted with a shared secret between the authorization server and - the resource server, or a key identifier that can be used by the - resource server to lookup the session key. + to determine the actual secret when no explicit "kid" was provided in + the "psk_identity" field. Usually, this is done by including a + "COSE_Key" object carrying either a key that has been encrypted with + a shared secret between the authorization server and the resource + server, or a key identifier that can be used by the resource server + to lookup the shared secret. Instead of the "COSE_Key" object, the authorization server MAY include a "COSE_Encrypt" structure to enable the resource server to - calculate the session key from the Access Token. The "COSE_Encrypt" + calculate the shared key from the Access Token. The "COSE_Encrypt" structure MUST use the _Direct Key with KDF_ method as described in - Section 12.1.2 of RFC 8152 [12]. The authorization server MUST + Section 12.1.2 of RFC 8152 [13]. The authorization server MUST include a Context information structure carrying a PartyU "nonce" parameter carrying the nonce that has been used by the authorization - server to construct the session key. + server to construct the shared key. This specification mandates that at least the key derivation algorithm "HKDF SHA-256" as defined in [RFC8152] MUST be supported. This key derivation function is the default when no "alg" field is included in the "COSE_Encrypt" structure for the resource server. 4.2. Updating Authorization Information Usually, the authorization information that the resource server keeps for a client is updated by uploading a new Access Token as described in Section 2.2. - If the security association with the resource server still exists and - the resource server has indicated support for session renegotiation - according to [RFC5746], the new Access Token MAY be used to - renegotiate the existing DTLS session. In this case, the Access - Token is used as "psk_identity" as defined in Section 4.1. The - Client MAY also perform a new DTLS handshake according to Section 4.1 - that replaces the existing DTLS session. - - After successful completion of the DTLS handshake the resource server + The Client MAY also perform a new DTLS handshake according to + Section 4.1 that replaces the existing DTLS session. After + successful completion of the DTLS handshake the resource server updates the existing authorization information for the client according to the new Access Token. 5. Security Considerations This document specifies a profile for the Authentication and Authorization for Constrained Environments (ACE) framework [I-D.ietf-ace-oauth-authz]. As it follows this framework's general approach, the general security and privacy considerations from section 6 and section 7 also apply to this profile. @@ -663,28 +651,29 @@ Reference: [RFC-XXXX] 8. References 8.1. Normative References [I-D.ietf-ace-oauth-authz] Seitz, L., Selander, G., Wahlstroem, E., Erdtman, S., and H. Tschofenig, "Authentication and Authorization for - Constrained Environments (ACE)", draft-ietf-ace-oauth- - authz-10 (work in progress), February 2018. + Constrained Environments (ACE) using the OAuth 2.0 + Framework (ACE-OAuth)", draft-ietf-ace-oauth-authz-13 + (work in progress), July 2018. [I-D.tiloca-tls-dos-handshake] Tiloca, M., Seitz, L., Hoeve, M., and O. Bergmann, "Extension for protecting (D)TLS handshakes against Denial - of Service", draft-tiloca-tls-dos-handshake-01 (work in - progress), October 2017. + of Service", draft-tiloca-tls-dos-handshake-02 (work in + progress), March 2018. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC4279] Eronen, P., Ed. and H. Tschofenig, Ed., "Pre-Shared Key Ciphersuites for Transport Layer Security (TLS)", RFC 4279, DOI 10.17487/RFC4279, December 2005, . @@ -712,31 +701,20 @@ [RFC8152] Schaad, J., "CBOR Object Signing and Encryption (COSE)", RFC 8152, DOI 10.17487/RFC8152, July 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 8.2. Informative References - [I-D.ietf-ace-cbor-web-token] - Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig, - "CBOR Web Token (CWT)", draft-ietf-ace-cbor-web-token-12 - (work in progress), February 2018. - - [I-D.ietf-tls-rfc4492bis] - Nir, Y., Josefsson, S., and M. Pegourie-Gonnard, "Elliptic - Curve Cryptography (ECC) Cipher Suites for Transport Layer - Security (TLS) Versions 1.2 and Earlier", draft-ietf-tls- - rfc4492bis-17 (work in progress), May 2017. - [RFC6655] McGrew, D. and D. Bailey, "AES-CCM Cipher Suites for Transport Layer Security (TLS)", RFC 6655, DOI 10.17487/RFC6655, July 2012, . [RFC7250] Wouters, P., Ed., Tschofenig, H., Ed., Gilmore, J., Weiler, S., and T. Kivinen, "Using Raw Public Keys in Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)", RFC 7250, DOI 10.17487/RFC7250, June 2014, . @@ -748,54 +726,67 @@ [RFC7748] Langley, A., Hamburg, M., and S. Turner, "Elliptic Curves for Security", RFC 7748, DOI 10.17487/RFC7748, January 2016, . [RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital Signature Algorithm (EdDSA)", RFC 8032, DOI 10.17487/RFC8032, January 2017, . + [RFC8392] Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig, + "CBOR Web Token (CWT)", RFC 8392, DOI 10.17487/RFC8392, + May 2018, . + + [RFC8422] Nir, Y., Josefsson, S., and M. Pegourie-Gonnard, "Elliptic + Curve Cryptography (ECC) Cipher Suites for Transport Layer + Security (TLS) Versions 1.2 and Earlier", RFC 8422, + DOI 10.17487/RFC8422, August 2018, + . + 8.3. URIs [1] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.8.1 + 13#section-5.8.1 [2] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.3 + 13#section-5.1.2 - [3] https://tools.ietf.org/html/rfc7252#section-9 + [3] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- + 13#section-5.3 - [4] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.8.1 + [4] https://tools.ietf.org/html/rfc7252#section-9 [5] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.1.1 + 13#section-5.8.1 [6] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.1.1 + 13#section-5.1.1 [7] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.6.3 + 13#section-5.1.1 [8] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.8.2 + 13#section-5.6.3 [9] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.1.2 + 13#section-5.8.3 [10] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- - 10#section-5.1.2 + 13#section-5.1.2 - [11] https://tools.ietf.org/html/rfc6749#section-5.2 + [11] https://tools.ietf.org/html/draft-ietf-ace-oauth-authz- + 13#section-5.1.2 - [12] https://tools.ietf.org/html/rfc8152#section-12.1.2 + [12] https://tools.ietf.org/html/rfc6749#section-5.2 + + [13] https://tools.ietf.org/html/rfc8152#section-12.1.2 Authors' Addresses Stefanie Gerdes Universitaet Bremen TZI Postfach 330440 Bremen D-28359 Germany Phone: +49-421-218-63906