Hi Roman, Thank you for your detailed comments. We addressed most of your comments in the latest version. Please find my comments inline.
On 3/23/21 4:32 AM, Roman Danyliw via Datatracker wrote: > > ---------------------------------------------------------------------- > DISCUSS: > ---------------------------------------------------------------------- > > (A simple editorial fix) Per Section 5.8.2 of [I-D.ietf-ace-oauth-authz], the > name of the parameter in the C-to-AS communication is “ace_profile” (not > “profile”). The “ace_profile” parameter is mistakenly referenced as “profile” > in the following places: > > -- Section 3.2.1: > The response MAY contain a "profile" parameter with the value > "coap_dtls" to indicate that this profile MUST be used for > communication between the client and the resource server. > > -- Section 3.3.1: > If the > profile parameter is present, it is set to "coap_dtls". Yes, you are correct. The name of the parameter changed in ace-oauth-authz-25 and this occurrence must have slipped through. > > > ---------------------------------------------------------------------- > COMMENT: > ---------------------------------------------------------------------- > > Thank you to Russ Mundy for the SECDIR review, and thank you to the authors > for > responding to it. > > ** Does this profile only cover part of the oauth-authz framework? Section > 3.3 > explicitly says “the use of introspection is out of scope for this > specification.” It might be helpful to note in the introduction that this > profile only covers C-to-AS and C-to-RS communication. We added to the introduction that introspection is out of scope for this specification. > > ** Section 3.2.1 Figure 3, uses the “req_aud” parameter, but this was renamed > to “audience” in -20 of draft-ietf-ace-oauth-authz Yes, fixed. > > ** Section 3.2.1. Per ‘The response MAY contain a "profile" parameter with > the > value "coap_dtls" to indicate that this profile MUST be used for communication > between the client and the resource server’, this is true (see the DISCUSS > above though). However, it might be worthwhile to point out that per Section > 5.8.2 of draft-ietf-ace-oauth-authz-38, this “MAY” is actually a MUST if the > request has an empty “ace_profile” parameter. Okay, fixed. > > ** Section 3.2.2. Per “This specification therefore mandates implementation > support for curve25519 ...”, perhaps RFC2119 language should be used here Okay, changed to MUST. > > ** Section 3.3.1. Per all of the text after “The method for how the resource > server determines the symmetric key from an access token containing only a key > identifier is application-specific; the remainder of this section provides one > example”, consider removing all of the RFC2119 language is this text as its an > example. The Gen-ART review from Paul Kyzivat of 19 Jul 2020 suggested to include the normative language to avoid ending up with unclear specifications. (The normative language has been added in https://github.com/ace-wg/ace-dtls-profile/commit/9ab383c0e08f8d4bff5335cbfadb1c6b48289472) > > ** Section 3.3.2. Per “When the resource server receives an access token, it > MUST check if the access token is still valid ...”, a reference to Section > 5.10.1.1 of [I-D.ietf-ace-oauth-authz] for additional verification procedures > might be helpful Okay, done. > > ** Section 3.2.2. and 7: > > (a) Section 3.2.2. > To be consistent with [RFC7252] which allows for shortened MAC tags > in constrained environments, 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]. > > (b) As this specification aims at constrained devices and > uses CoAP [RFC7252] as transfer protocol, at least the ciphersuite > TLS_PSK_WITH_AES_128_CCM_8 [RFC6655] should be supported > > The text in (b) is weaker on the mandatory required of the ciphersuite. In > (b), likely s/should be supported/must be supported/. Okay, changed b to MUST support. > > ** Section 7. Per “For longer-lived access tokens, DHE ciphersuites should be > used”, perhaps add a parenthetical at the end of this sentence of “(i.e., > ciphersuites of the form TLS_DHE_PSK_*)”. Fixed as suggested. > > ** Section 7.1. Session resumption is noted to be NOT RECOMMENDED. Is there > a > reason this can’t be stronger (MUST NOT)? Session resumption can be very useful for very constrained clients. We therefore changed it as follows: OLD: Therefore, the use of session resumption is NOT RECOMMENDED for resource servers. NEW: Therefore, session resumption should be used only in combination with reasonably short-lived PoP keys. > > ** Section 7.2. No issues with the guidance here. Is there anything DTLS > specific that suggests that developers "SHOULD" avoid multiple access tokens > per client? That guidance isn’t in the core framework. I made the comment on > the core framework that perhaps this text should be there (too?). We moved the respective paragraph to the framework document. > > ** Please reviews all of the reference numbers to [I-D.ietf-ace-oauth-authz] > as > a number of them seem to be incorrect (likely due to renumbering). For > example: Okay, checked and fixed. > > -- Section 2. Per “the client MUST upload the access token to the authz-info > resource, i.e. the authz-info endpoint, on the resource server before starting > the DTLS handshake, as described in Section 5.8.1 of > [I-D.ietf-ace-oauth-authz]”, Section 5.8.1 is not the right reference. It’s > likely 5.10.1. > > -- Section 3.4. Per “The authorization server may, e.g., specify a "cti" > claim for the access token (see Section 5.8.3 of [I-D.ietf-ace-oauth-authz]) > to > employ a strict order”, Section 5.8.3 is the wrong section in > [I-D.ietf-ace-oauth-authz]. > > -- Section 3.4. Per “The response SHOULD include AS Request Creation Hints as > described in Section 5.1.1 of [I-D.ietf-ace-oauth-authz].”, there is no > Section > 5.1.1. The appropriate section is either 5.2 to reference this behavior or 5.3 > for the details of the hints. > > -- Section 3.4. Per “Incoming CoAP requests received on a secure DTLS channel > that are not thus authorized MUST be rejected according to Section 5.8.2 of > [I-D.ietf-ace-oauth-authz]”, Section 5.8.2 is not the right reference here. > > ** idnits returned the following: > > == Unused Reference: 'RFC8152' is defined on line 1148, but no explicit > reference was found in the text Fixed (added reference in the draft) > > == Unused Reference: 'RFC8613' is defined on line 1212, but no explicit > reference was found in the text Fixed (removed) > > ** Nits > -- Section 7.1. Typo. s/renogiation/renegotiation/ Fixed. Thank you for your time, Steffi _______________________________________________ Ace mailing list Ace@ietf.org https://www.ietf.org/mailman/listinfo/ace
