* Section 3.1 - Refresh Token - I don't think that refresh tokens are going to be strings because binary is more efficient.
* Section 3.2 - we need to reference TLS 1.3 even if DTLS 1.3 is not yet available. * Description for Figure 6 - Should the example somehow indicate in the message that it is going to be an application/ace+cbor content. Also, I don't know that this is a good example in some ways because this is not a currently documented profile anywhere. * Section 5.6.3 - Should the content type for an error response be application/ace+cbor ? * Section 5.7.1 - Is the content format for a request application/ace+cbor? I assume it is but that is not documented in this section. Section 5.8 - bytes arrays or byte strings? I think CBOR uses the latter * Section 5.8.1 - What is the purpose of creating an identifier for a token? Is this supposed to be used rather than the one from the AS for something like shared secret TLS? Note that this is an unprotected value. * Section 5.8.1 - Given the change in the OSCORE profile, you might want to make this an application/ace+cbor structure as well. * Section 5.8.1 - If the token is "not valid" is the RS required (i.e. MUST) to try introspection before returning a response if the RS does introspection? The text currently says MAY. If this is really MAY then the text should say that the token is always successfully accepted by the RS. * Section 5.8.2 - If the RS is going to do introspection, can it send some type of "Server Busy - try again in xxx" while it does the introspection rather than just doing an ack of the request and possibly waiting a long time? * Section 5.8.3 - third point - I think that the correct text would be "The method does not provide timely expiration, but it makes sure that older tokens will cease to be valid after newer issued tokens are registered with the RS." My problem is that just issuing tokens is not enough as they may be going to a different RS for use. This may also need to have some type of rate limit to issued tokens or making the sequence number be on an RS/audience basis. * Section 6. - The recommendation not to use a shared secret for an audience which is hosted by multiple servers is interesting. This does require that a multiple recipient COSE structure be used and it may be worth calling that out. Also the size of the CWT is going to grow for that. You are also now losing the low-level authentication and thus a signature wrapping is now also needed. * Section 6 - "Developers MUST" para - May want to add that this can also be mitigated to some extent by making sure that keys roll over more frequently. * Section 6 - I am not sure that I agree with the SHOULD NOT in the last paragraph. Think multicast. * Section 6.4 - This also applies to sending back some type of identifier from the RS->C when a token is registered. * Section 8.6.1 - Is pop still this document or is it Mike's document? * Section 8.9 - The description of reference is wrong. * Section 8.12 - some of these should move to the OAuth parameters document? * Section 8.13 - ditto * Appendix A - para "CBOR, COSE, CWT" - Is it really a requirement to use CBOR or is that a recommended? I thought this was part of what Hannes was looking at. * Appendix A - para Client Credentials Grant s/can the/can then/ * Registries - I am wondering if we should think about re-writing a couple of the registries. As things stand it appears that the application/ace+cbor content type is being used in 5 or 6 places. It might make more sense to have a registry for all of the CBOR abbreviations that are being used in a single table and have multiple columns for each of the different places were the content format is being used. This would make it easier to keep everything constant and can make re-use of integer values easier to see. * Comments on protection of CWT/Token: I am wondering if there needs to be any comments on how a CWT is going to be protected. While it is ok to use either a symmetric key or a direct key agreement operation for a single recipient without forcing a signature operation to occur. If the token is going to be targeted a single audience hosted on multiple RSs then a signature operation would be required for the purposes of authentication. * I am not sure where this issue should be raised so I am putting it here. Both of the profiles have as their last security consideration a statement that the use of multiple access tokens is a bad idea. Both of them also devote a large section of text to how to deal with multiple access tokens as does this document. More methods of having multiple access tokens seem to be coming down the path from the OAuth group. This appears to be a distinct contradiction within the set of documents that should be resolved. Jim _______________________________________________ Ace mailing list Ace@ietf.org https://www.ietf.org/mailman/listinfo/ace