jiebi/CodeConvo huggingface dataset:
As discussed, this is a) hard to do in all cases, b) impossible to do in many, and c) not that useful.
good
When multiple connections share the same network path or multiple connection IDs are used for the same path, using the spin bit is complicated by the difficulty in correlating forward and reverse flows. There is currently text that uses RFC 6919 language in the draft recommending coordination of the spin to avoid this problem. However, as , this coordination seems difficult and therefore unlikely. It also creates a strong signal that indicates that all the connections on the path are terminated at the same endpoint on both ends. Maybe we don't want to be generating that signal. Also, because this coordination can't be guaranteed, the on-path observer is forced to build code for correlating/segregating measurements by connection ID in the case where there is no coordination. Maybe it's best just to remove this recommendation entirely.
+1 to removing the recommendation, or changing the statement to just a caution (e.g., if you are to coalesce connections that spin, then you'd better be aware of ...). FWIW I am not sure if I agree with this observation. IIUC, the connections sharing a 5-tuple will be terminated by the same endpoint on both ends; it is impossible for a middlebox to coalesce multiple QUIC connections. It is impossible because CIDs can change mid-connection, and a middlebox cannot determine to where the packets containing the new CID must be sent.
There definitely needs to be a degree of coordination between the middlebox and the endpoints, but that doesn't mean that you can't use something like the quic-lb stuff on either end (or both ends).
Yes, I think it is better to remove that recommendation, but perhaps replace it with a note to observers.
s/prevention/interference/ ... Censors can degrade performance to a particular site, or for a particular service, effectively making performance so bad for a site that users opt to use a different site or service. China is known to do this. Censors can try to have content removed via takedown requests, under the guise of laws that forbid certain content (e.g., hate speech or whatnot). The ANC is .za has been accused of using the laws in this fashion.
Will Scott also noted in feedback to me that throttling should get more of a call out than it currently does:
Looks good to me.
... are considered a 'bad smell'. Instead of a date vs. a fixed string, could we just say that a date in the past is equal to 'true'?
i guess we could. and we already say that a date in the past means that the resource is deprecated. the motivation to allow a flag was to not force services to make up a date when they don't have one and simply want to flag something as deprecated. but we could also "force" them to make up a date by not allowing the "true" flag. i am fine either way and i do see the point that the syntax may cause some implementations to not parse the field correctly. maybe others can weigh in as well?
FWIW, I see it like Expires -- if it's already stale, you just assign a date in the past.
i could definitely live with such a design.
One use case was to align the header's usage with API contract as defined using OpenAPI. Having boolean helps align this header with OpenAPI's flag which does not require date. Forcing API developers to add a random date in the past in case if it is not available due toe various reasons would not be desirable for various other reasons (SLA?). Although, I wish that OpenAPI adds date for . >If the deprecation date is not known, the header field can carry the simple string "true", indicating that the resource context is deprecated, without indicating when that happened: On Jul 31, 2021, at 06:46, Mark Nottingham NAME wrote: FWIW, I see it like Expires -- if it's already stale, you just assign a date in the past.
For Expires, January 1 1970 (epoch 0) is widely used.
NAME I wish OpenAPI supported deprecated date also. But when we do, it won't be with a property that can be boolean or date.
Ok NAME thanks for clarification on the OpenAPI side of things. I agree. We can just use date. There are some implementations out there, I would not know if any of those use boolean but since we are not an RFC yet, such a change should not be unexpected.
it seems like we can safely remove the alternative syntax. i have created a PR asking for review by NAME
LGTM
This may be answered and I just missed it. After reading I think that for HTTP/1 and HTTP/2 Datagrams (via capsules) can only be sent for new methods/upgrade tokens. But it wasn't clear to me if that same property was true for HTTP/3. For example, would it be valid to send HTTP/3 datagrams along with a GET request? If so, I think this means that for HTTP/3 a GET request could have both a body AND datagrams?
That's a very good point. If anything, we should be prescriptive about what endpoints do if they receive a datagram associated with an existing method like GET. I suspect drop or error are the most likely candidates here.
I vote for close the connection with error. The datagram has the relate to something in the request. If the request doesn't or cannot articulate a datagram use, the sender of datagram is probably broken or stupid.
Since datagrams are strongly associated with a stream, I think it'd be more consistent to make this a stream error. Regardless, folks my want an extension to GET that allows sending datagrams with it, but it makes sense to require that this extension be negotiated via headers or settings first, so the semantics of such datagrams are agreed upon beforehand. So, I'm supportive of making this a stream error, with the understanding that any extension can lift this requirement between consenting parties.
I'd prefer to make people suffer but I could live with a stream error. Like you suggest, by letting people people agree on a change of requirements, we support extension. But the default of erroring helps datagram avoid the mess othat GET with body is.
Also, I reserve the right to count the number of these failures and close the connection if it reaches my annoyance threshold
Ah yes . Sounds good, I'll write up a PR for this once the design team PRs are landed.
Sounds good to me. An extension could just as easily lift a connection error requirement as it could a stream error requirement in case that had any bearing on the thinking here. (A connection error might be nice because it prevents a confused peer from sending a possibly incessant stream of datagrams.
On the other hand, confused peers gonna be confused and David's point about datagrams being strongly associated with a request is a good point)
I think it should be a stream error to enable method-agnostic gateways and proxies, which may be multiplexing different clients' traffic onto a single next-hop connection.
In , NAME points out that Content-Type doesn't make sense with the capsule protocol. Should we prohibit it?
In , NAME points out that status codes 204, 205, and 206 don't make sense with the capsule protocol. Should we prohibit them?
The spec currently says: In HTTP/1.x, the message content is generally delineated by the Content-Length header field or the Transfer-Encoding; another request can follow on the same connection. One of the (many) ways in which CONNECT and Upgrade are special is that in H1 it takes over the connection and makes the request extend to the end of the connection, preventing any further requests from being made. The description attempts to be generic about method, but implicitly assumes an indefinite length stream of bytes which (in H1) is only true of CONNECT or Upgrade. This concept is correct for what we have in mind, but the boundaries aren't crisply described right now. NAME may have opinions.
The sentence right after the bit you pasted is: That constrains this to CONNECT/Upgrade/new methods. Is that not enough?
I think "new methods" is probably the most questionable. It's not clear to me that a new method can obtain the special behaviors of CONNECT. If it were restricted to upgrade tokens (whether with HTTP/1.1 Upgrade or RFC 8441 Extended CONNECT), I think that would address the concern.
I believe what he means is this definition of a data stream only holds for CONNECT requests. There is no mechanism to extend that to new request methods since all other methods are required to have length-delimited data (or no data).
Likewise, I don't know of any reason we would want to support such extension methods in the future, since that is a known failure point for CONNECT. It is far simpler for a new method to require chunked or data frames.
Restricting this to extended CONNECT and Upgrade sounds reasonable to me
For Upgrade, the new protocol takes over after the current response is complete. Hence, the description above doesn't really work for Upgrade either.
NAME the intent of that text was to mean "after the current response is complete" - do you have a proposal for phrasing that would work better?
Semantics says: URL I think is consistent with the definition of "data stream" in this document. (And in fact uses the term "data stream" without defining it.) That doesn't seem to match deferring the new protocol until after the response.
I don't think there is any technical distinction between the two descriptions; it's nomenclature to say that what follows the CONNECT is a tunnel ended by connection closure, whereas what follows Upgrade is a different protocol that might very well come back to this one (as determined by the other protocol).
And point to URL This is an important part of the security analysis.
Only if you believe that the Sec- prefix is useful for the Capsule-Protocol header field. I don't.
Sorry, I don't mean that it's the only thing that makes it work, merely that if were going to talk about how to analyze it, this is something we should say.
NAME can you clarify your intent? Your issue title starts with "Add to JS" but I suspect you didn't mean that we should modify the JavaScript specification. Would a note next to where the "Capsule-Protocol" header is defined resolve this?
Aaargh. I meant "add to the security considerations".
Thanks, that makes more sense :) Adding something to security considerations sounds good to me, I'll add text to the . Note that this was filed on the wrong repository, is the droid you're looking for.
So this assumption is useful in that it helps us avoid an analysis. Though my sense is that that analysis isn't especially difficult. The header field exists to enable datagram forwarding behaviour in an intermediary. We only have to show that there is no harm inflicted if a client engages that behaviour for requests, under the constraint that the client is otherwise authorized to make from a web context. The risk comes if this forwarding behaviour somehow generates different semantics as a result. As the same client also provides the stream of data that will be forwarded, it is trivial to see that they are already in a position to engage whatever semantics they choose.
The only scenario that might benefit an attacker is where the elision of datagrams (or things that look like them) might be used to evade security protections that scan the stream of data. For an attack to be effective, those same protections would have to be ignorant of datagram forwarding behaviour at the same intermediary. This binding to CONNECT is a useful shortcut that means we don't need to engage with all that stuff, which wouldn't be that easy to write down. (This aversion to engagement is, I believe, a large part of why people want to slap "Sec-" on all new headers.)
MT's framing of this is helpful. Adding some security consideration about what might go wrong for an intermediary seems potentially useful. Spending text on why a browser is special in this regard seems less compelling to nme.
I was about to write a PR for this, but I think we should first If we decide that capsules are only allowed for HTTP upgrade tokens (and not new methods) then we've restricted ourselves to CONNECT and Upgrade which are both inaccessible from JavaScript.
LGTM thanks
Addresses and . The server hint came up in the context of QUIC, e.g., as a possible optimization to let clients know if they should expect any post handshake messages. cc NAME NAME
Looks like this got merged without any business days to review it :) but otherwise the text looks good, approved.
Every day is a business day! ;-)
From NAME
Fixed by .
You probably want to be clear that ticket_request cannot appear in HRR, given that you have a section on it.
Fixed in .
I'm not a huge fan of sending extensions that aren't really needed, but this seems fine. I missed the QUIC discussion (or maybe it's still in my inbox). BTW, I still like the idea of hoisting tickets to the application layer, but ekr seems to think that they belong at the TLS layer. I guess we'll just have to keep disagreeing on that point :)
` The loader environment only exists for a second or two, and has few resources… how it is supposed to report evidence to a verifier in that window?
Refers to figure 3, in section 3.4, on layered attestation.
It is rare that early layers generate or convey Evidence. In critical system with appropriate protected capabilities that actually happens. I can see that it is not a common case and would not argue strongly against removing 'B' from that conveyance arc.
Perhaps a better example for which the loader environment is not ephemeral would be where B is the OS and C is an application/workload process.
Comment by NAME In How does a client know this? Preconfiguration ? Are we talking ms? sec? minutes? Any advise to implementers ?
It can't be less than 2s, because the granularity of the field doesn't permit detecting anything finer than 1s. I've done what I can.
This still does not seem to address: Maybe just cut off the “unless” part if there is no signal for this? Paul
NAME also included URL which I think should address your concern:
Thanks. That commit does address the issue, mostly. I guess it moves it do an unspecified provisioning layer :P Paul
Signed-off-by: David Navarro
NAME NAME and others: Any response to John's comment?
NAME I included John's suggestion in the PR.
Looks good to me. Other opinions?
As specified in section , the payload in some CoAP messages can be an EDHOC message prepended by either a C_x identifier or "true". The draft states: However, the payload is actually a CBOR Sequence as defined by . Thus, we could define and use a new media type "application/edhoc+cbor-seq". Note that the usage of the Content-Format option is optional.
Makes sense to me. NAME NAME others: Comments? Good that you bring up the optionality of Content-Format, we should stress that in this text. The discussion in Hackathon also reminded me about the common-option-compression which NAME presented in the May 12 interim 2021 - how to replace the Uri-Path: "/.well-known/edhoc" with a, say, integer valued CoAP option.
Makes a lot of sense to me, too.
I find this distinction good and the solution consequential, still open for comments.
(Last two commits on wrong branch.)
The prototype of EDHOC-Exporter() has remained EDHOC-Exporter(label, length), while it should be EDHOC-Exporter(label, context, length) as per Alternative 3 discussed in issue URL Correct?
Thanks NAME your comment is addressed in the latest commit. I merge this now.
The text use both the terms "session" and "protocol instance", would be good to settle for one term.
Just chose one, I don't think this needs an issue
In the security considerations "session" makes most sense to me. There is also the term "connection". I will make a proposal.
The spec should likely forbid multiple calls to the EDHOC-Exporter interface with the same label, in order to prevent the same key being reused. Discussed with NAME and NAME
Good catch. Yes, we should have some text about that, but it should probably more be a requirement on the application using EDHOC that on EDHOC itself. Two different application should defintly not use the same label. The same application might rederive the same key several times as long as it keep track of its AEAD nonces and replay window. I thought that we had already IANA registry proposed for this, but that is not the case. We should probably have one. If we have a IANA registry the labels get more fixed and it might be that we need a context input parameter as well.
If we make a IANA registrer for labels, I think we need to let the application add additional information in some way. Two alternatives: We make an IANA register for label prefixes, and let the application append information to the label prefix. This was recently planned for EAP-TLS (and methods built on EAP-TLS) but was changes because the TLS export labels are not really ment to be labels. This would not change the current exporter interface. We expand the interface with a context parameter. This is similar to the TLS exporter. A problem with the TLS exporter is that some implementations decided to not even support context.
NAME how is the context parameter intended to be used? Could you give an example? Would this be some sort of "salt" when deriving the key?
Don't register labels, register label prefixes.
The motivation for "context" or "label postfixes" is to increase the flexibility for the application. Restricting the application to IANA registered labels is very limiting. An application might want to use the EDHOC exporter to derive a number of keys and we should encourage that. The alternative is that the application needs to implement its own key derivation, which might be less secure and might be outside of the TEE. I called it "context" just because TLS calls the paramater in its exporter context.
"Be like TLS" is of course a good motivation. Technically, a label prefix is not different from a context, it just saves the need to separate prefix and suffix.
(And of course there is nothing wrong with multiple calls with the same label; the application has a "right to forget" :-)
The solutions should be equal when it comes to security. The choice should be made based on what is easiest for implementators and apllications using EDHOC. Alt 1. We make an IANA register for label prefixes: "OSCORE Master Secret" "OSCORE Master Salt" The Export function stays the same: EDHOC-Exporter(label, length) = EDHOC-KDF(PRK4x3m, TH4, label, length) An application is allowed to append things to the label prefix: "OSCORE Master Secret" "OSCORE Master Secret PickleRick" Alt 2. We make an IANA register for labels: label = "OSCORE Master Secret" label = "OSCORE Master Salt" The Export function needs to change: EDHOC-Exporter(label, ctx, length) = EDHOC-KDF(PRK4x3m, TH4, [label, ctx] , length) An application is not allowed to append things to the label and uses the ctx instead: label = "OSCORE Master Secret" ctx = "" label = "OSCORE Master Secret" ctx = "PickleRick"
No major opinion. Alt 2 breaks the test vector for the OSCORE security context. It would be good to get more input.
Any preference NAME NAME NAME ?
If desired the CTX is more convenient it can always be added in a wrapper on top of EDHOC-Exporter(). (I assume re-use of label+ctx in Alt 2 is equivalent to re-use of label in Alt 1?)
I prefer to have explicitly specified.
We can pass to the concatenation of and . When is undefined/empty, test vectors are not affected. I guess this is what NAME is referring to?
label is a CBOR byte string. While alt 2 use an CBOR array. Definging alt2 as a wrapper seems more complication in my view.
Would be good if people stated alt 1. or alt 2. or made a concrete suggestion for alt 3.
Alt 3 (CBOR sequence) We make an IANA register for labels: label = "OSCORE Master Secret" label = "OSCORE Master Salt" The Export function needs to change: EDHOC-Exporter(label, ctx, length) = EDHOC-KDF(PRK4x3m, TH4, labelcontext, length) where is a CBOR sequence: If you want to keep the test vectors intact, then you could make optional in the CDDL, but not sure how to specify an optional parameter in the interface definition.
Thanks. That is a valid alt 3. but ctx should probably be a bstr
I don't think keeping the test vectors intact is an important goal at all. Let's decide on what is simplest for a user of the exporter interface.
Something like that, yes. Later post do differentiate the type of "label" and "ctx" and in light of that and changing test vectors Alt3 seems clean.
I am fine with alt 3. I can start making PR for that unless somebody has different ideas. I don't alt 1 is a good alternative anymore as is restricts context to being a unicode string. Which would require some base64 encoding or similar for a general context.
Please review alt. 3 as specified in . Unless there are any comments we would like to merge this.
This is included in -07 so I close the issue.
Comment by Martin Disch in URL "The draft does a good job of pointing to the right places in RFC 8152, but I still ended up trying to understand another ~100 page document just to implement the few constructs I actually needed." Should we provide more details about COSE constructs, e.g. in appendix A.2?
(pasting my response from the mailing list here for completeness) Thanks for following up on this. Yes, in my opinion expanding on the COSE constructs would be helpful.
But I also sympathize with not wanting to duplicate what is already defined in another RFC (and possibly getting it wrong, as Carsten points out). Considering that there are quite a few implementers already and besides mine you have only received one other similar comment, maybe this isn't an issue for a meaningful majority. In any case, the draft has made great strides already in terms of accessibility and is in a good state now, so I don't see improvements in this area as an absolute necessity.
The two COSE constructs that are used in EHDOC, and are fairly simple. They don't use the recursive structure or embed . I think it is possible to add some additional clarifications on the structure of the COSE messages in the EHDOC draft without having to copy too much text from RFC 8152. As part of a thesis I built a proof-of-concept implementation of EDHOC in the Rust programming language available at URL The naming of the repository is due to the subject being both EDHOC and OSCORE on embedded devices, but the following refers only to the EDHOC implementation. It's based on draft-selander-ace-cose-ecdhe-14 and as such, sadly, outdated. Since it was just one part of the overall work, I only managed to implement the subset I needed, which is RPK and the signature-signature based scheme (corresponding to what draft-selander-lake-edhoc calls method 0). I also took some other shortcuts, such as not supporting auxiliary data. Fortunately, test vectors were about to be introduced just around the time I was working on it, so I've been able to successfully verify my implementation against them when John shared them with me for some preliminary testing. Since I didn't have any prior experience implementing this kind of software, I would definitely consider it more of an experiment, but it's out there and it works, in case it can be useful to anybody. I'm convinced that EDHOC will be valuable particularly in the context of OSCORE, possibly even beyond that. As for the draft itself, I would like to mention one aspect that I think could be improved from the perspective of an implementer. Part of the promise of EDHOC is that it's simple and lightweight due to reusing COSE.