Question: "struct { Extension extensions<0..2^32-1>; } GroupContextExtensions; " <del> A member of the group applies a GroupContextExtensions proposal by removing all of the existing extensions from the GroupContext object for the group and replacing them with the list of extensions in the proposal.  (This is a wholesale replacement, not a merge.  An extension is only carried over if the sender of the proposal includes it in the new list.)  Note that once the GroupContext is updated, its inclusion in the confirmation_tag by way of the key schedule will confirm that all members of the group agree on the extensions in use. </del> <ins> A member of the group applies a GroupContextExtensions proposal with the following steps: If the new extensions include a "required_capabilities" extension, verify that all members of the group support the required capabilities (including those added in the same commit, and excluding those removed). Remove all of the existing extensions from the GroupContext object for the group and replacing them with the list of extensions in the proposal.  (This is a wholesale replacement, not a merge.  An extension is only carried over if the sender of the proposal includes it in the new list.) Note that once the GroupContext is updated, its inclusion in the confirmation_tag by way of the key schedule will confirm that all members of the group agree on the extensions in use. </ins> 11.1.9.

Proposal: Preparatory PR: Rationalize layout Move "Cryptograhic Objects" to before "Ratchet Trees" Update "Ratchet Tree Nodes" to define ParentNode and LeafNode structs, with LeafNode initially just equal to KeyPackage Move subsections of "Key Packages" to under "Ratchet Trees" Parent Hash Tree Hashes Update Paths Move Group State to its own top-level section Main PR: Change LeafNode to have the required content: HPKE key for TreeKEM Credential Parent hash Capabilities Extensions Signature Change KeyPackage to refer to LeafNode for internals, plus: HPKE key for Welcome Lifetime Extensions Signature Add continues to send KeyPackage Update and Commit send LeafNode instead of KeyPackage Remove and Sender refer to LeafNodeRef instead of KeyPackageRef We should probably do the preparatory PR regardless of this issue.
Discussion on working call: General agreement on the approach Should sign group_id when possible Include in TBS if we at least have a flag for pre-published / in-group Or we can store it Or we could have independent structs for pre-published / in-group leaves Do we need extensions at both levels? Capabilities / lifetime should probably be promoted to fields
Many protocols which have an extensibility mechanism have a way to indicate that understanding an extension is mandatory for certain behaviors. For MLS, this would mean having a way to require a member understand an MLS extension before it can join a group. The three extension types defined currently are: MLS ciphersuites, MLS extension types, and MLS credential types. One logical way to add mandatory extensions would be to pick one of these types (the MLS extensions type) and use the high order bit or a specific range to indicate that a member must understand and implement the extension to join a group which uses that extension. The IANA values could be changed as follows: Values from 0x8000-0xffff indicate understanding the extension is required 0x7f00 - 0x7fff Reserved for Private Use (not required) 0xff00 - 0xfff Reserved for Private Use (required) If a required ciphersuite or credential becomes necessary, a new extension type could be created to add an extension in the KeyPackage or GroupInfo which would be required and would indicate support for the mandatory ciphersuites or credentials.


Question: "struct { Extension extensions<0..2^32-1>; } GroupContextExtensions; " <del> A member of the group applies a GroupContextExtensions proposal by removing all of the existing extensions from the GroupContext object for the group and replacing them with the list of extensions in the proposal.  (This is a wholesale replacement, not a merge.  An extension is only carried over if the sender of the proposal includes it in the new list.)  Note that once the GroupContext is updated, its inclusion in the confirmation_tag by way of the key schedule will confirm that all members of the group agree on the extensions in use. </del> <ins> A member of the group applies a GroupContextExtensions proposal with the following steps: If the new extensions include a "required_capabilities" extension, verify that all members of the group support the required capabilities (including those added in the same commit, and excluding those removed). Remove all of the existing extensions from the GroupContext object for the group and replacing them with the list of extensions in the proposal.  (This is a wholesale replacement, not a merge.  An extension is only carried over if the sender of the proposal includes it in the new list.) Note that once the GroupContext is updated, its inclusion in the confirmation_tag by way of the key schedule will confirm that all members of the group agree on the extensions in use. </ins> 11.1.9.

In order to prevent some other entity from adding an MLS client that does not support a mandatory extension, we already have the KeyPackage Client Capabilities, which lists which extensions are supported by the client.
Note that though this might seem "now or never", I don't think it really is. Consider TLS by way of analogy -- it has no mechanism for specifying that extensions are required. But if a server gets a ClientHello that is missing some extension that it requires, it can just abort the handshake. Likewise in MLS, the member adding a new joiner to the group can examine that joiner's KeyPackage to see if they support the extensions needed for the group. So I think you could implement this as a non-mandatory GroupContext extension, which would state the extensions required by the group so that all members apply the same requirements for new joiners.
While you can implement this "out-of-band", that makes it implicit rather than explicit behavior.
Discussed at 20211004 interim, liked this functionality. But, instead of IANA registry use field (or extension) in group context to indicate which extensions are required. NAME to generate PR.
Discussed with NAME and incorporated this functionality into PR


Question: "signer".  If the node is blank or if signature verification fails, return an error. <ins> Verify that the "group_id" is unique among the groups that the client is currently participating in. </ins> Verify the integrity of the ratchet tree. Verify that the tree hash of the ratchet tree matches the

Brendan to revise based on Rohan suggestion.
Interim 2022-05-26: Concerns around making the group_id totally random Malicious group creator can choose it malicious Federated systems get worse randomness Using AEAD.Nk depends on ciphersuite, could be awkward NAME will revise to say: Here are the requirements that group ID must satisfy If you don’t have an alternative plan, do it randomly
Group ids are signed to bind certain information to specific groups. But I can imagine a case where a user mis-uses the group id to be something like a "room title" which lets an adversary control the group id and introduces potential problems. If we can prove that it's fine for a group id to be reused, then should we get rid of group ids? If not (as I expect), then group ids need to be guaranteed to be unique [globally per signing key] and we need to specify that.
Discussed at 19 May interim. NAME to generate PR documenting fresh random value approach.
Virtual interim 2022-05-19: Agreement that some sort of uniqueness requirement is worthwhile Main question is what scope of uniqueness should be Globally? Within scope of DS? Fresh random value? Simple, but precludes application usage of the field Also could help avoid metadata leakage Client / DS should probably still check for collisions NAME to write up a PR on the fresh random value idea
Group IDs must be generated randomly by creator Clients and DS must check that group ids are unique as far as they know


Question: GroupSecrets object with the "psks" field set, the receiving Client includes them in the key schedule in the order listed in the Commit, or in the "psks" field respectively.  For resumption PSKs, the PSK is <del> defined as the "resumption_secret" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </del> <ins> defined as the "resumption_psk" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </ins> Here "0" represents the all-zero vector of length "KDF.Nh".  The "index" field in "PSKLabel" corresponds to the index of the PSK in

Looks good! I would maybe add 1 sentence explaining the rule for what is called a secret and what is called a key. The rule says that a secret will go through some key derivation to obtain a key/keys, is that right?
NAME Yep, that's exactly right. Added a sentence. Thanks for the feedback everyone!
Reopening due to incomplete discussion and inaccuracy. The claims presented are incorrect in response by NAME demonstrate a misunderstanding of the roles of these keys and uses, and constitutes a change to the fundamental uses thereof. The authenticationsecret is NOT a public value nor was it ever introduced as such. If an application is using it as a public value, that onus is on the developers, and I advise against using Cisco's implementation as a standard for MLS. As shown in the name and all original discussion, the authenticationsecret is intended as a secret value (or else 'public' in the same way that the group secret is 'public). It is used for further derivation to support authentication. This should be corrected, and such foundational changes without WG discussion should be avoided.
Clearly we have a disagreement here NAME but maybe let's hold off on attributing misunderstanding. It seems like you are claiming that in order for MLS to be secure, the needs to be protected to the same level as the . What is this based on? If that is true, then we should probably remove the altogether. The "out-of-band" protocol in which it would be confirmed would have to be part of the MLS security analysis, thus no longer out-of-band.
NAME that is not the claim at all - different uses imply different compromise risks. This should not be a new concept to understand. As demonstrated in the terminology, the authenticationsecret is linked to authentication, not confidentiality. MLS, per specification, outsources authentication (the AS is not explicitly defined and all entity authentication within MLS relies on it). Even though it is definitionally out-of-scope and therefore out-of-band (certificates, authentication verification are entirely out-of-band of the protocol spec), we do not say that signature secret keys can be "public" - yet you are asserting that an authenticationsecret which can support epoch-level authentication would be public.


Question: GroupSecrets object with the "psks" field set, the receiving Client includes them in the key schedule in the order listed in the Commit, or in the "psks" field respectively.  For resumption PSKs, the PSK is <del> defined as the "resumption_secret" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </del> <ins> defined as the "resumption_psk" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </ins> Here "0" represents the all-zero vector of length "KDF.Nh".  The "index" field in "PSKLabel" corresponds to the index of the PSK in

The authenticationsecret is private in the same way that the exportervalue is: based on key schedule derivation, compromise of these keys should not undermine MLS, but secrecy of them can be leveraged. So, unless you are now proposing removing mention of certificates, etc. from the core protocol, there really isn't a logical basis for removing 'out-of-band' authentication mechanisms.
What I'm trying to get at here is: What is the negative consequence if an is known by someone other than the members of a group? For example, leaking a signature private key would enable the attacker to impersonate the corresponding member. Leaking the would allow the attacker to decrypt all of the group's messages. What is the bad consequence of an becoming public?
NAME I am also assuming that this push to use epoch-level authentication values as public codes is based on Cisco's implementation choice. I would be curious to know why there is such insistence that all implementations also go about using authentication in the same way. If an implementation chooses to use it as a secret value to then derive an authentication code based on yet other information, why is that a problem?
Publishing the authenticationsecret as a public value has a similar effect as publishing the exportervalue as public - it is not an issue for MLS per protocol spec, but it would definitely be an issue for the application if it is then used for something secret thereafter. One reason not to specify these as public values is that they are derived following the conditions placed on keys and therefore could be used as secret values if desired by an application. Forcing or annotating them as immediately public, or as final 'codes', when such a use as a secret key is an out-of-scope potential is artificial and unnecessary.
I'm not pushing anything, I'm just trying to get the protocol to be clear. If this thing needs to be secret, then it needs to be secret, and we need to document that so that people keep it secret. Thanks for elaborating more on your concerns. I see what you're saying -- basically the same point that NAME and I discussed . I think the core of the disagreement here is what we mean when we say that a value is "public" or "secret".


Question: GroupSecrets object with the "psks" field set, the receiving Client includes them in the key schedule in the order listed in the Commit, or in the "psks" field respectively.  For resumption PSKs, the PSK is <del> defined as the "resumption_secret" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </del> <ins> defined as the "resumption_psk" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </ins> Here "0" represents the all-zero vector of length "KDF.Nh".  The "index" field in "PSKLabel" corresponds to the index of the PSK in

I mean something very specific: That the security guarantees of MLS will not be harmed if a public value is provided to the attacker, and they will be harmed if a secret value is provided to the attacker. Importantly, "public" does not mean that the value must be published, or that the security guarantees of an application using MLS will not be harmed if you publish the value. It seems to me that in that specific taxonomy, the is "public" and not "secret". Do you disagree?
BTW, the notion of something being "public" at one layer but "secret" at another is not new. For example, values exported from TLS aren't secret in the sense that publishing them would compromise TLS. You could authenticate your TLS connection by exporting a value and shouting it through megaphones across a crowd. But the main way people use them in practice is as secrets in some other protocol. Every WebRTC call uses SRTP keys that are exported from TLS, and many people would be very sad if these "public" values were published.
If it would help, I would be happy to add some text to the Security Considerations clarifying this distinction. Basically, draw a clear boundary around which values have to be kept confidential to the client in order to realize the security properties of the protocol. But I still think is a clearer name. Doesn't mean you have to use it in any particular way in your application; doesn't prevent it being used as a shared secret; but also doesn't imply that the MLS library has to worry about its secrecy.
Within the bounds of that particular taxonomy there is not an issue. However, while you may be following a given taxonomy, that is not a general one, one that would be widely understood by implementors, nor is it specified in the protocol spec. It is not an unreasonable taxonomy, but it certainly not a general one. If you are looking for MLS usage spec to align to your taxonomy then I do think that there should be a clarification section added. BTW as a point case on more standard terminology use, the TLS 1.3 spec uses the exact phrasing for exporters as "exportermastersecret", from which the actual exporter may be derived. This aligns very closely to the authenticationsecret, from which an authentication code later may be derived.


Question: GroupSecrets object with the "psks" field set, the receiving Client includes them in the key schedule in the order listed in the Commit, or in the "psks" field respectively.  For resumption PSKs, the PSK is <del> defined as the "resumption_secret" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </del> <ins> defined as the "resumption_psk" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </ins> Here "0" represents the all-zero vector of length "KDF.Nh".  The "index" field in "PSKLabel" corresponds to the index of the PSK in

TLS is generic in 'exporters' after an exportermastersecret is derived. Thus there is alignment of the term 'secret' to things that can be used for keys (have sufficient entropy), not as an alignment to public/secret at different layers. I am strongly opposed to the use of authenticationcode, and see no clear definition for that in your customized taxonomy. As such, it would follow the more standard interpretations, such as message authentication codes, etc. which are indeed explicitly public values. Codes are normally an end-state in themselves, not keys. Perhaps it is a clearer name for the Cisco implementation design, but it is not a clear name for something that can/should be used for further derivations as may be more generally applicable. Following the TLS norm for exporters, the name would be "authenticationmastersecret". The shortened "authenticationsecret" was a good name. If you are going to provide a write-up for the custom taxonomy, then an adjustment to "authenticationexporter" could perhaps be made.
The notion of a having boundary to the protocol and values that may or may not safely be exported across the boundary is not exotic or customized. You see it in FIPS 140-2, PKCS, and WebCrypto, and in tools like ProVerif and Tamarin. The only choice I'm making is in the specific words, in particular reserving "secret" for "something that should not be exposed outside the protocol implementation because it would compromise the protocol". I hope you agree that is different from say in this regard. It would be OK for an MLS implementation to have an API for an application to access the , but it would not be OK to have an API to access the . I'm not wedded to , I just want something other than . If you want to align with the exported values (to which I agree it is similar), we could call it an .
The distinction between those documents and tools, and the MLS spec is that those tools clearly define the boundaries and terminology, vs. just anyone making terminology assumptions without them being specified in the document. Not to be pedantic, but if you want to assume specific meanings for terms relative to a threat model for MLS only, versus a general usage ("exporter secrets" being secrets used in other things), then you really do need to specify those assumptions within the specification itself and not various side discussions.


Question: GroupSecrets object with the "psks" field set, the receiving Client includes them in the key schedule in the order listed in the Commit, or in the "psks" field respectively.  For resumption PSKs, the PSK is <del> defined as the "resumption_secret" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </del> <ins> defined as the "resumption_psk" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </ins> Here "0" represents the all-zero vector of length "KDF.Nh".  The "index" field in "PSKLabel" corresponds to the index of the PSK in

Such specification is part of what a standard is meant to do. Within other documents this is clearly defined - i.e., what is known as a threat model - such as one sees in ProVerif and Tamarin. Assuming that you are going to add such a taxonomy, and that it follows that described by you in , then the correct term would be "authenticationkey". To quote you what you said there, which correctly aligns to a reasonable usage of the authenticationkey. pointed out that there is a lack of consistency in the usage of "keys" vs "secrets" throughout the document - something that still has not been addressed and should not be dropped from the issue for edits. Regardless of what taxonomy is being used or even assumed, there is no consistency in it in the spec. You seem to be commenting on adjustments only for the "key" and "secret" uses that appear as variables, but the commentary within the spec interchangeably use these terms for the same thing. Whatever is used should be applied consistently. It is not reasonable to assume that developers will correctly guess reasons for terminology separations particularly when they are inconsistently enforced.
On your latter point about usage of "keys" vs "secrets" throughout the document — Sorry if I misinterpreted your intent here. If you're seeing places where there are inconsistencies, it would be helpful if you could highlight those more specifically, or ideally send a PR to fix them.
NAME had a call about this today and hashed out a couple of things: We should be clear in general about what we mean by secrets/keys, in that we generally use them interchangeably, but sometimes use one or the other to indicate how a specific value is used The need for secrecy of the value labeled depends on the context in which it is used. So we should provide some text to suggest that there are different ways to use it, and use a fairly neutral name. NAME suggested , which I like a lot. I have attempted to implement these in
The spec currently uses a mix of terminologies for keys/secrets.


Question: GroupSecrets object with the "psks" field set, the receiving Client includes them in the key schedule in the order listed in the Commit, or in the "psks" field respectively.  For resumption PSKs, the PSK is <del> defined as the "resumption_secret" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </del> <ins> defined as the "resumption_psk" of the group and epoch specified in the "PreSharedKeyID" object.  Specifically, "psk_secret" is computed as follows: </ins> Here "0" represents the all-zero vector of length "KDF.Nh".  The "index" field in "PSKLabel" corresponds to the index of the PSK in

In the key schedule we have the following: senderdatasecret | "sender data" encryptionsecret | "encryption" exportersecret | "exporter" authenticationsecret | "authentication" externalsecret | "external" confirmationkey | "confirm" membershipkey | "membership" resumptionsecret | "resumption" It would be best to provide a coherency to how we use these terms and check for consistency throughout, to avoid confusion for readers: A simple solution would be to use "secret" for all cases, i.e., changing membershipkey to membershipsecret.Another alternative, which may take more refining but could be useful to readers is to separate out terms based on items that are for internal protocol use versus external protocol use. For example, encryption, confirmation, membership, etc., would use "key" and exporter, authentication, etc., could use "secret", or vice versa. --Break-- Ref the mailinglist on confirmation vs authentication secrets, perhaps the naming of these two are a little misleading - authentication normally being within bounds of a protocol while confirmation is external to it. This confusion probably sparked some of that discussion to begin with. It could_ be worth considering switching those terms for clarity.
I actually think we have a fairly coherent taxonomy here: "secret" is something that gets fed into HKDF to derive further things "key" is something that gets fed into another algorithm, e.g., HMAC Looking through the list, the ones that deviate from this pattern are: , which is exported to the application but expected to be kept private , which is exported to the application but not expected to be kept private Given that, I would propose we update the table in question to something like the following, using because that's how it's used, and to follow the "security code" terminology used by applications:
Things are easier to understand like this! The "Purpose" column is quite valuable I think, I remember I was quite overwhelmed when I first read it and had no idea what all those secret / keys were used for. This helps to understand the big picture.


Question: An alternative is to rely on periodic email summaries of activity, such as those produced by a notification tool like github-notify-ml <del> [6].  This tool has been used effectively in several working groups, </del> <ins> [5].  This tool has been used effectively in several working groups, </ins> though it requires server infrastructure. A working group that uses GitHub MAY provide either facility at the

I was tempted to remove the entire section on administrative policies, though left it as is. NAME what do you think?
Yeah, I figured it best to start small. Let me know if you need anything else before merging!
NAME Interesting that the circle CI build ran on the merge, but not the PR. I didn't see any build failures reported before it merged, but I just got the email reporting a missed reference. Maybe there are some tweaks you need to apply over there as owner of the org.
Yeah, I'll fix it. Thanks for letting me know!
I was thinking of being a little more aggressive about removing some of the text, with matching PRs for the other work, but this works.


Question: "signature_algorithms" is REQUIRED for certificate authentication. <del> "supported_groups" and "key_share" are REQUIRED for DHE or ECDHE key exchange. </del> <ins> "supported_groups" is REQUIRED for ClientHello messages using DHE or ECDHE key exchange. "key_share" is REQUIRED for DHE or ECDHE key exchange. </ins> "pre_shared_key" is REQUIRED for PSK key agreement.

Even when (EC)DHE is in use, the "supported_groups" extension is only mandatory in the ClientHello; it can be omitted from the EncryptedExtensions, as per section 4.2.6. Given that, it is not MTI for the server sending to the client, but the client must be prepared to accept the extension in EncryptedExtensions (at least to the point of not crashing or aborting the handshake), so leave the MTI text unchanged. It would be too awkward to try to express this subtlety in such a concise list.


Question: Data whose semantics depends on the Capsule Type. <ins> Unless otherwise specified, all Capsule Types are defined as opaque to intermediaries.  Intermediaries MUST forward all received opaque CAPSULE frames in their unmodified entirety.  Intermediaries MUST NOT send any opaque CAPSULE frames other than the ones it is forwarding. All Capsule Types defined in this document are opaque, with the exception of the DATAGRAM Capsule, see datagram-capsule.  Definitions of new Capsule Types MAY specify that the newly introduced type is transparent.  Intermediaries MUST treat unknown Capsule Types as opaque. Intermediaries respect the order of opaque CAPSULE frames: if an intermediary receives two opaque CAPSULE frames in a given order, it MUST forward them in the same order. </ins> Endpoints which receive a Capsule with an unknown Capsule Type MUST <del> silently drop that Capsule.  Intermediaries MUST forward Capsules, even if they do not know the Capsule Type or cannot parse the Capsule Data. </del> <ins> silently drop that Capsule. Receipt of a CAPSULE HTTP/3 Frame on a stream that is not a client- initiated bidirectional stream MUST be treated as a connection error of type H3_FRAME_UNEXPECTED. </ins> 4.1.

NAME points out that in order to correctly forward DATAGRAMs between transports where the QUIC DATAGRAM frame isn't always available, intermediaries need the ability to parse some capsules.
CAPSULE was easier to understand when it was fully opaque. When should I choose to define a semi-opaque CAPSULE vs defining a new frame? Aren't both constructs effectively hop-by-hop?
NAME you're the one who asked for this :-) The benefit of a semi-opaque capsule is that it allows defining new capsules without having to update every single intermediary in the chain, because intermediaries forward all unknown capsules.


Question: be perceived as creating a conflict of interest for a particular MLS DE, that MLS DE SHOULD defer to the judgment of the other MLS DEs. <ins> 18.6. This document registers the "message/mls" MIME media type in order to allow other protocols (ex: HTTP RFC7540) to convey MLS messages. </ins> 19.  References 19.1.  URIs

This is a minimal section for MIME type registration of message/mls. It assumes that PR include wire_format in all MLS messages (making a format parameter unnecessary), and that all messages have the MLS version number encoded (making a version parameter unnecessary). These parameters can be added if needed.
When MLS messages are transmitted over a protocol which supports Content-Type / MIME Type negotiation, signal that the message is an MLS message. Because MLS messages are really a bag of formats today we should have a MIME type parameter which specifies the specific format included. message/mls;format={applicationgroupcontext}
This seems like a fine idea to me. Could go as a section in the protocol spec, or as a separate (small) spec.
Discussion on virtual interim: Section or separate doc? How do we handle versioning? Internal to the protocol (field in MLSMessage?) Field in the MIME type Different MIME type per version
I would prefer a short section in the protocol document. I think Internal to the protocol is cleanest. Likewise the format parameter becomes unnecessary if we add Welcome, PublicGroupState, and KeyPackage to wire_format (see issue )
NAME send a PR?
Asking for friend: would we want to define (or use) a structured syntax suffix ala ?
NAME If you mean for multiple formats, no, we have only one encoding. If someone wants to re-encode the protocol as XML or whatever, a MIME type will be the least of their troubles.
Fixed in


Question: mpls and I-D.ietf-detnet-ip.  This draft does not have additional security considerations. <del> 5. </del> <ins> 7. </ins> This document makes no IANA requests.

Based on 06.17 discussions. F-lables(s) added to Fig1 and text fixed. Adding procedures sections. Multiple notes added for clarifications. Adding controller plane section.
reviewed in Jun 24 meeting


Question: 1. <del> The Internet does not always provide end to end reachability for native DNS.  On-path network devices may spoof DNS responses, block DNS requests, or just redirect DNS queries to different DNS servers that give less-than-honest answers.  These are also sometimes delivered with poor performance or reduced feature sets. Over time, there have been many proposals for using HTTP and HTTPS as a substrate for DNS queries and responses.  To date, none of those proposals have made it beyond early discussion, partially due to disagreement about what the appropriate formatting should be and partially because they did not follow HTTP best practices. </del> This document defines a specific protocol for sending DNS RFC1035 queries and getting DNS responses over HTTP RFC7540 using https:// (and therefore TLS RFC5246 security for integrity and

This text is great justification to include in a charter, but this is a protocol specification and it really doesn't add much.
It seemed like the WG wanted the document to be shorter and more specific, so this feels good.


Question: Many application programming interfaces (APIs) to perform transport networking have been deployed, perhaps the most widely known and <del> imitated being the BSD socket() POSIX interface.  The naming of objects and functions across these APIs is not consistent, and varies </del> <ins> imitated being the BSD Socket POSIX interface.  The naming of objects and functions across these APIs is not consistent, and varies </ins> depending on the protocol being used.  For example, sending and receiving streams of data is conceptually the same for both an unencrypted Transmission Control Protocol (TCP) stream and operating on an encrypted Transport Layer Security (TLS) RFC8446 stream over <del> TCP, but applications cannot use the same socket send() and recv() calls on top of both kinds of connections.  Similarly, terminology for the implementation of transport protocols varies based on the context of the protocols themselves: terms such as "flow", "stream", "message", and "connection" can take on many different meanings. This variety can lead to confusion when trying to understand the similarities and differences between protocols, and how applications can use them effectively. </del> <ins> TCP, but applications cannot use the same socket "send()" and "recv()" calls on top of both kinds of connections.  Similarly, terminology for the implementation of transport protocols varies based on the context of the protocols themselves: terms such as "flow", "stream", "message", and "connection" can take on many different meanings.  This variety can lead to confusion when trying to understand the similarities and differences between protocols, and how applications can use them effectively. </ins> The goal of the Transport Services architecture is to provide a common, flexible, and reusable interface for transport protocols.  As

Closed
I just read Arch and have the following NiTs which I think we should address: /Listeners by default register with multiple paths/ ought this to be: /Listeners, by default, register with multiple paths/ /A Framer is a data translation layer that can be added to a Connection to define how application-level Messages are transmitted over a transport protocol. / I think this should be (because I don’t think they are protocol specific) /A Framer is a data translation layer that can be added to a Connection to define how application-level Messages are transmitted over the transport service. / /to retransmit in the event of packet loss,/ better to avoid event here :-) /to retransmit when there is packet loss,/
I am just gonna add a few more nits here: The Listener object in figure 4 is a bit awkward, it appears as if the Listen() call appears out of thin air while per the API it gets called on the preconnection object like Initiate() and Rendezvous(). In section 4.1.1, there are 5 references to section 4.1.2, is it really necessary to have that many? Point 2 in section 4.2.3 only talks about required transport services, the same should probably be said about prohibited services, i.e. "both protocol stacks MUST NOT offer transport services prohibited by the application"
Let me add to this: Section 1: print send() and recv() in fixed-with font [HTML/XML issue only] Section 2 - Figure 1: socket() [with the brackets] looks odd in the figure title
NAME I fear framers may be specific to the underlaying protocol, e.g., for SIP slicing messages out of TCP stream whereby doing nothing for SCTP and UDP
In relation to frames I think I only asked to add /service/ instead of protocol... I don't understand how Phil's comment reacts to that
NAME I think protocol is correct here and would not change the sentence.
OK - so I think you are saying the framer depends only on the specific next protocol, rather than upon the transport service that was offered? - It is still not clear to me that this is correct.
NAME that is a fairly good question… The behaviour of the framer defiantly depends on the transport service provided (which may be a subset or superset of the transport service requested).


Question: Many application programming interfaces (APIs) to perform transport networking have been deployed, perhaps the most widely known and <del> imitated being the BSD socket() POSIX interface.  The naming of objects and functions across these APIs is not consistent, and varies </del> <ins> imitated being the BSD Socket POSIX interface.  The naming of objects and functions across these APIs is not consistent, and varies </ins> depending on the protocol being used.  For example, sending and receiving streams of data is conceptually the same for both an unencrypted Transmission Control Protocol (TCP) stream and operating on an encrypted Transport Layer Security (TLS) RFC8446 stream over <del> TCP, but applications cannot use the same socket send() and recv() calls on top of both kinds of connections.  Similarly, terminology for the implementation of transport protocols varies based on the context of the protocols themselves: terms such as "flow", "stream", "message", and "connection" can take on many different meanings. This variety can lead to confusion when trying to understand the similarities and differences between protocols, and how applications can use them effectively. </del> <ins> TCP, but applications cannot use the same socket "send()" and "recv()" calls on top of both kinds of connections.  Similarly, terminology for the implementation of transport protocols varies based on the context of the protocols themselves: terms such as "flow", "stream", "message", and "connection" can take on many different meanings.  This variety can lead to confusion when trying to understand the similarities and differences between protocols, and how applications can use them effectively. </ins> The goal of the Transport Services architecture is to provide a common, flexible, and reusable interface for transport protocols.  As

A framer needs to support all possible outcomes of the transport services requested It may optimize based on the protocols it actually finds, e.g., turn into a no-op with the transport preserves message boundaries. Whether the next protocol is a sufficient representation of this is unclear to me. Maybe not, if one thinks of supporting arbitrarily large messages and UDP over IPv6 with and without fragmentation…
LGTM, thanks!


Question: Reasons for signing the zone by the HNA are: <del> 1) Keeping the Homenet Zone and the Public Homenet Zone equal to </del> <ins> Keeping the Homenet Zone and the Public Homenet Zone equal to </ins> securely optimize DNS resolution.  As the Public Zone is signed with DNSSEC, RRsets are authenticated, and thus DNS responses can be validated even though they are not provided by the

…ument, dealing with issue
handling different views (7.0) .... some would like to have different views, This document deals with the view that the Internet gets from the CPE(s) only.


Question: This key is automatically mandatory if present.  (See Section 7 of SVCB for the definition of "automatically mandatory".) <ins> Support for the "port" key can be unsafe if the client has implicit elevated access to some network service (e.g. a local service that is inaccessible to remote parties) and that service uses a TCP-based protocol other than TLS.  A hostile DNS server might be able to manipulate this service by causing the client to send a specially crafted TLS SNI or session ticket that can be misparsed as a command or exploit.  To avoid such attacks, clients SHOULD NOT support the "port" key unless one of the following conditions applies: The client is being used with a DNS server that it trusts not attempt this attack. The client is being used in a context where implicit elevated access cannot apply. The client restricts the set of allowed TCP port values to exclude any ports where a confusion attack is likely to be possible (e.g. the "bad ports" list from the "Port blocking" section of FETCH). </ins> 4.3. These SvcParamKeys from SVCB apply to the "dns" scheme without

Closes URL
Allowing the use of nonstandard port numbers in SVCB for DNS provides valuable operational flexibility, but it also creates a risk related to cross-protocol confusion attacks, in which a malicious server convinces a client to send TCP contents that can be misparsed as a different protocol by a non-TLS victim server. For example, a malicious DNS server could indicate an SNI or session ticket that can be misparsed as a command by a recipient server, and use DNS rebinding to change its own apparent IP address to the victim server. Clients would then send this server-controlled payload to the victim server. This is dangerous if the client is implicitly authorized to control the victim server (e.g. authorization by IP address). Note that only DoT and DoH (over TCP) are amenable to these attacks. QUIC Initial encryption ensures that the packet has no meaning to a recipient that is not QUIC-aware, and any QUIC-aware recipient should not be vulnerable to these attacks. We should consider ways to minimize the impact of these attacks. For example, we could require clients to restrict the value of the parameter to a small fixed list, or refer to the . Credit to NAME


Question: the result is "LogicalTrue"; if the function's declared result type is "NodesType", it tests whether the result is non-empty.  If the function's declared result type is "ValueType", its use in a test <del> expression is not well-typed. </del> <ins> expression is not well typed. </ins> Comparison expressions are available for comparisons between primitive values (that is, numbers, strings, "true", "false", and

Also, delete a term which is used only in the definition of the next term. Fixes URL
I only found the two occurrences you suggested changing. If there are others, please let me know!
Sometimes the spec uses "Singular Query" and sometimes "singular query". We should be consistent. (If we decide to use lower case, it's probably best to address this issue after PR has been merged, since that PR adds some usages of "Singular Query".) Also, there is one instance of "Logical context", which I think would be better uncapitalised ("logical context").
Thanks.


Question: the radio resource has been in the core design of SATellite COMmunication (SATCOM) systems.  The trade-off often resided in how much redundancy a system adds to cope from link impairments, without <del> reducing the good-put when the channel quality is high.  There is </del> <ins> reducing the good-put when the channel quality is good.  There is </ins> usually enough redundancy to guarantee a Quasi-Error Free <del> transmission.  However, physical layer reliability mechanisms may not recover transmission losses (e.g. with a mobile user) and layer 2 (or above) re-transmissions induce 500 ms one-way delay with a geostationary satellite.  Further exploiting coding schemes at higher OSI-layers is an opportunity for releasing constraints on the physical layer in such cases and improving the performance of SATCOM systems. </del> <ins> transmission.  The recovery time depends on the encoding block size. Considering for instance geostationary satellite system (GEO), physical or link layers erasure coding mechanisms recover transmission losses within a negligible delay compared to link delay. However, when retransmissions are triggered, this leads to an non- negligible additional delay in particular over GEO link.  Further exploiting coding schemes at application or transport layers is an opportunity for releasing constraints on the physical layer and improving the performance of SATCOM systems. </ins> We have noticed an active research activity on coding and SATCOM in the past.  That being said, not much has actually made it to

Answer to issue
A first sentence says quasi-error-free is usually guarranteed thanks to redundancy, while the following sentence tends to say the opposite. Not very clear.The intro fails to clarify the targets. Among them there is "coding to recover from packet losses" (to avoid confusion with bit-error corrections), but also "coding to improve the usage of radio resource". You should also clarify better what is meant by coding: it's not a content coding (e.g., to compress a video flow) but rather a computation of linear combination of packets. Say since the begining you'll rely on RFC8406 whenever possible. Parts of the text currently in section 3 (1st paragraph) deserve to be moved here.Typo: s/to cope from/to cope with/
We have updated the introduction structure and changed the usage of coding in the whole document. We hope this is better. cf PR and PR
this is cherrypicking, not discussing link/channel FEC (Error) or ACK. the heading should really be 'of network coding schemes'. "to cover cases where where"? At the physical layer, FEC mechanisms can be exploited.-- Erasure or Error? "Based on public information, coding does not seem to be widely used at higher layers." it isn't, and that section can be reduced to just that sentence.
Vincent in item X1, 1st sentence, it suggests QUIC is a video streaming application. Change it.Fig. 2 raises a general question: it refers to upper applications that are by nature on the end-hosts. Everything is imaginable here and this is not specific to a SATCOM system. Why don't you limit yourself to the communication layers + middleware? I'm a bit confused.When you say: "Based on public information, coding does not seem to be widely used at higher layers." I guess you limit yourself to the "packetization UDP/IP + middleware" but do not consider upper applications. It's also confusing.
We think that these comments have been assessed with PR
"However, physical layer reliability mechanisms may not recover transmission losses (e.g.


Question: the radio resource has been in the core design of SATellite COMmunication (SATCOM) systems.  The trade-off often resided in how much redundancy a system adds to cope from link impairments, without <del> reducing the good-put when the channel quality is high.  There is </del> <ins> reducing the good-put when the channel quality is good.  There is </ins> usually enough redundancy to guarantee a Quasi-Error Free <del> transmission.  However, physical layer reliability mechanisms may not recover transmission losses (e.g. with a mobile user) and layer 2 (or above) re-transmissions induce 500 ms one-way delay with a geostationary satellite.  Further exploiting coding schemes at higher OSI-layers is an opportunity for releasing constraints on the physical layer in such cases and improving the performance of SATCOM systems. </del> <ins> transmission.  The recovery time depends on the encoding block size. Considering for instance geostationary satellite system (GEO), physical or link layers erasure coding mechanisms recover transmission losses within a negligible delay compared to link delay. However, when retransmissions are triggered, this leads to an non- negligible additional delay in particular over GEO link.  Further exploiting coding schemes at application or transport layers is an opportunity for releasing constraints on the physical layer and improving the performance of SATCOM systems. </ins> We have noticed an active research activity on coding and SATCOM in the past.  That being said, not much has actually made it to

with a mobile user) and layer 2 (or above) re-transmissions induce 500 ms one-way delay with a geostationary satellite" Look, forward error coding (FEC) and link ACKs are complementary on a sliding scale depending on delay/channel quality, and this is talking solely about retransmissions. In fact, link or channel FEC do recover a large number of transmission bit/symbol losses without adding extra delay.
We have clarified this point in PR


Question: expected to be relevant for a closed connection.  Retransmitting the final packet requires less state. <del> New packets from unverified addresses could be used to create an amplification attack; see address-validation.  To avoid this, endpoints MUST either limit transmission of CONNECTION_CLOSE frames to validated addresses or drop packets without response if the response would be more than three times larger than the received packet. After receiving a CONNECTION_CLOSE frame, endpoints enter the draining state.  An endpoint that receives a CONNECTION_CLOSE frame MAY send a single packet containing a CONNECTION_CLOSE frame before entering the draining state, using a CONNECTION_CLOSE frame and a NO_ERROR code if appropriate.  An endpoint MUST NOT send further packets, which could result in a constant exchange of CONNECTION_CLOSE frames until the closing period on either peer ended. </del> <ins> While in the closing state, an endpoint could receive packets from a new source address, possibly indicating a connection migration; see migration.  An endpoint in the closing state MUST either discard packets received from an unvalidated address or limit the cumulative size of packets it sends to an unvalidated address to three times the size of packets it receives from that address. </ins> <del> An immediate close can be used after an application protocol has arranged to close a connection.  This might be after the application protocols negotiates a graceful shutdown.  The application protocol exchanges whatever messages that are needed to cause both endpoints to agree to close the connection, after which the application requests that the connection be closed.  When the application closes the connection, a CONNECTION_CLOSE frame with an appropriate error code will be used to signal closure. 10.2.1. </del> <ins> An endpoint is not expected to handle key updates when it is closing (Section 6 of QUIC-TLS).  A key update might prevent the endpoint from moving from the closing state to the draining state, as the endpoint will not be able to process subsequently received packets, but it otherwise has no impact. 10.2.2. The draining state is entered once an endpoint receives a CONNECTION_CLOSE frame, which indicates that its peer is closing or draining.  While otherwise identical to the closing state, an endpoint in the draining state MUST NOT send any packets.  Retaining packet protection keys is unnecessary once a connection is in the draining state. An endpoint that receives a CONNECTION_CLOSE frame MAY send a single packet containing a CONNECTION_CLOSE frame before entering the draining state, using a NO_ERROR code if appropriate.  An endpoint MUST NOT send further packets.  Doing so could result in a constant exchange of CONNECTION_CLOSE frames until one of the endpoints exits the closing state. An endpoint MAY enter the draining state from the closing state if it receives a CONNECTION_CLOSE frame, which indicates that the peer is also closing or draining.  In this case, the draining state SHOULD end when the closing state would have ended.  In other words, the endpoint uses the same end time, but ceases transmission of any packets on this connection. 10.2.3. </ins> When sending CONNECTION_CLOSE, the goal is to ensure that the peer will process the frame.  Generally, this means sending the frame in a

I took a careful look at the text here and found a few things: There wasn't much redundancy, but there was a little. Mostly the problem was scattering of content between two locations in the document. The closing and draining states only apply to immediate close. So I moved things up. I trimmed the top-level immediate close text, and moved text specific to closing or draining to sections corresponding to each. There were a few bits that could be cut, and a few that needed to be better aligned with existing text, but nothing major. Most of this is unmodified text. There are a few bits that I had to tweak. I will add comments for those.
NAME you can add this to your review load.
The section on Immediate Close contains some text that is redundant with the section on the Closing and Draining periods. Factor some of this out.
I think this flows a lot better. Thanks for the time you put into this!Thanks, Martin!


Question: different online protocol. Intra-data-center communication.  Machine-to-machine communication <del> within a single data center or PoP may use externally provisioned PSKs, primarily for the purposes of supporting TLS connections with early data; see security-con for considerations when using early data with external PSKs. </del> <ins> within a single data center or point-of-presence (PoP) may use externally provisioned PSKs, primarily for the purposes of supporting TLS connections with early data; see security-con for considerations when using early data with external PSKs. </ins> Certificateless server-to-server communication.  Machine-to- machine communication may use externally provisioned PSKs,

Address comments from IESG evaluation. Due to the holiday season, we may not get prompt confirmation that these changes fully resolve the comments.


Question: topic is used to correlate push messages sent to the same subscription and does not convey any other semantics. <del> The grammar for the Topic header field uses the "token" and "quoted- string" rules defined in RFC7230. Any double quotes from the "quoted-string" form are removed before comparing topics for equality. </del> <ins> The grammar for the Topic header field uses the "token" rule defined in RFC7230. </ins> For use with this protocol, the Topic header field MUST be restricted to no more than 32 characters from the URL and filename safe Base 64

NAME suggested this. It's a simplification that should reduce errors. It prevents topics like "Hello world!", but that's probably a good thing on balance.


Question: As a domain may resolve to multiple IPv4 and IPv6 addresses, the server will connect to at least one of the hosts found in A and AAAA <del> records, at its discretion.  The HTTP server may be made available over either HTTPS or unencrypted HTTP; the client tells the server in its response which to check. </del> <ins> records, at its discretion.  Because many webservers allocate a default HTTPS virtual host to a particular low-privilege tenant user in a subtle and non-intuitive manner, the challenge must be completed over HTTP, not HTTPS. </ins> The string "simpleHttp"

On the mailing list, NAME and NAME pointed out some risks arising from the default virtual host behavior of some web servers. This PR integrates the changes they suggest, namely (1) removing the "tls" option from the challenge, and (2) adding iterations to the challenge. This PR is based on top of and .
Sorry, feel free to tell me to go away, but reading the backing decision to drop HTTPS for SimpleHTTP doesn't make sense to me. If I understand everything correctly, you control the originator of the HTTPS requests and the requests are always sent to domains. So why can't you just enforce to always send the Host header and this wouldn't be an issue?
From : behaviour that if a default TLS/HTTPS virtual host is not configured explicitly, one will be selected based on the ordering of vhosts in the webserver configuration (in practice, this often amounts to alphabetical ordering of files in a configuration directory). As far as I know Apache does the exact same thing for nonencrypted HTTP hosts (this is also acknowledged by a later mail in the thread), so the reasoning is a little weird. I suppose the idea is that hosters are more likely to have HTTP configured correctly rather than HTTPS?
The section on the "" registry says that "Fields marked as "client configurable" may be included in a new-account request". This seems like a copy-paste-o, and perhaps should say that such fields may be included in a new-order request.
Good catch. I opened URL to fix. Thanks! Apache (and I gather nginx too) have the subtle and non-intuitive behaviour that if a default TLS/HTTPS virtual host is not configured explicitly, one will be selected based on the ordering of vhosts in the webserver configuration (in practice, this often amounts to alphabetical ordering of files in a configuration directory). URL URL This creates a vulnerability for SimpleHTTP and DVSNI in any multiple-tenant virtual hosting environment that failed to explicitly select a default vhost [1]. The vulnerability allows one tenant (typically one with the alphabetically lowest domain name -- a situation that may be easy for an attacker to arrange) to obtain certificates for other tenants.


Question: As a domain may resolve to multiple IPv4 and IPv6 addresses, the server will connect to at least one of the hosts found in A and AAAA <del> records, at its discretion.  The HTTP server may be made available over either HTTPS or unencrypted HTTP; the client tells the server in its response which to check. </del> <ins> records, at its discretion.  Because many webservers allocate a default HTTPS virtual host to a particular low-privilege tenant user in a subtle and non-intuitive manner, the challenge must be completed over HTTP, not HTTPS. </ins> The string "simpleHttp"

The exact conditions for the vulerability vary: SimpleHTTP is vulnerable if no default vhost is set explicitly, the server accepts the "tls": true parameter as currently specified, and the domains served over TLS/HTTPS are a strict subset of those served over HTTP. DVSNI is vulnerable if no default vhost is set explicitly, and the hosting environment provides a way for tenants to upload arbitrary certificates to be served on their vhost. James Kasten and Alex Halderman have done great work proposing a fix for DVSNI: URL That fix also has some significant performance benefits on systems with many virtual hosts, and the resulting challenge type should perhaps be called DVSNI2. The simplest fix for SimpleHTTP is to remove the "tls" option from the client's SimpleHTTP response, and require that the challenge be completed on port 80. URL Alternatively, the protocol could allow the server to specify which ports it will perform SimpleHTTP and SimpleHTTPS requests on; HTTPS on port 443 SHOULD be avoided unless the CA can confirm that the server has an explicitly configured default vhost. The above diffs are currently against Let's Encrypt's version of the ACME spec, we'll be happy to rebase them against the IETF version upon request. [1] though I haven't confirmed it, it's possible that sites that attempted to set a default vhost are vulernable if they followed advice like this when doing so: URL ; an attacker need only sign up with a lexicographically lower name on that hosting platform to obtain control of the default. Peter Eckersley EMAIL Chief Computer Scientist Tel +1 415 436 9333 x131 Electronic Frontier Foundation Fax +1 415 436 9993


Question: 9. <del> The application can set per-connection Protocol Properties (see protocol-props).  Certain Procotol Properties may be read-only, on a protocol- and property-specific basis.  ~~~ Connection.SetProperty(property, value) ~~~ </del> <ins> 9.1. The application can set per-connection Properties.  Certain Connection Properties may be read-only, on a protocol- and property- specific basis.  ~~~ Connection.SetProperty(property, value) ~~~ </ins> At any point, the application can query Connection Properties.  ~~~ ConnectionProperties := Connection.GetProperties() ~~~

This is the second step towards applying our new Properties Classification. It moves up the Connection Properties and annotates most places with stuff to do.
As discussed in
Thanks for moving this forward! I only found a few nits. Also, I have a question about whether two of these Properties should maybe be changed to be Selection Properties, but that's more of a discussion and not something that needs to be done in this URL modulo NAME commentsI carefully checked it, but I find it very hard to be sure that this is 100% ok (as is usually the case IMO with diff's about text blocks being moved around). My suggestion is to land it and see.


Question: This parameter holds a part of the IV value.  When using the COSE_Encrypted structure, frequently a portion of the IV is part of the context associated with the key value.  This field is used <del> to carry the portion of the IV that changes for each message.  As the IV is authenticated by the encryption process, this value can be placed in the unprotected header bucket.  The 'Initialization Vector' and 'Partial Initialization Vector' parameters MUST NOT be present in the same security layer. The final IV is generated by concatenating the fixed portion of the IV, a zero string and the changing portion of the IV.  The length of the zero string is computed by taking the required IV length and subtracting the lengths of the fixed and changing IV portions. </del> <ins> to carry a value that causes the IV to be changed for each message.  As the IV is authenticated by the encryption process, this value can be placed in the unprotected header bucket.  The 'Initialization Vector' and 'Partial Initialization Vector' parameters MUST NOT be present in the same security layer. The message IV is generated by the following steps: Left pad the partial IV with zeros to the length of IV. XOR the padded partial IV with the context IV. </ins> This parameter holds a counter signature value.  Counter signatures provide a method of having a second party sign some

This was inspired by the IV computation for TLS. It may or may not make things more secure. The old behavior is easy to get by making the context IV have trailing zeros.


Question: This section lists some example use-cases where pair-wise external PSKs, i.e., external PSKs that are shared between only one server and <del> one client, have been used for authentication in TLS. </del> <ins> one client, have been used for authentication in TLS.  There was no attempt to prioritize the examples in any particular order. </ins> Device-to-device communication with out-of-band synchronized keys. PSKs provisioned out-of-band for communicating with known


Question: transitively via an Endorser (e.g., the Verifier puts the Endorser's public key into its trust anchor store).  In layered attestation, a root of trust is the initial Attesting Environment.  Claims can be <del> collected from or about each layer.  The corresponding claims can be </del> <ins> collected from or about each layer.  The corresponding Claims can be </ins> structured in a nested fashion that reflects the nesting of the <del> Attester's layers. </del> <ins> Attester's layers.  Normally, Claims are not self-asserted, rather a previous layer acts as the Attesting Environment for the next layer. Claims about a root of trust typically are asserted by Endorsers. </ins> The device illustrated in layered includes (A) a BIOS stored in read- only memory, (B) an updatable bootloader, and (C) an operating system

Added clarifying text -
" including roots of trust" from .
We should add the sentence "Normally, claims are not self-asserted by a layer or root of trust." in the section describing layered attester / layering. around line 1120?
I'd not object that. I'd be okay with "Normally, claims are not self-asserted by a root of trust."


Question: fields; this document uses "fields" for generality. A name-value pair sent as part of an HTTP field section.  See <del> Sections 6.3 and 6.5 of SEMANTICS. </del> <ins> Sections 6.3 and 6.5 of RFC9110. </ins> Data associated with a field name, composed from all field line values with that field name in that section, concatenated together

These track corrections I've asked the RFC Editor to make directly in their copy prior to publication. It appears that some http-core sections moved since the last time we did a full sweep of our references.


Question: Relying Party or for a Verifier, then integrity of the process is compromised. <del> The security of conveyed information may be applied at different layers, whether by a conveyance protocol, or an information encoding format.  This architecture expects attestation messages (i.e., Evidence, Attestation Results, Endorsements, Reference Values, and Policies) are end-to-end protected based on the role interaction </del> <ins> The security protecting conveyed information may be applied at different layers, whether by a conveyance protocol, or an information encoding format.  This architecture expects attestation messages (i.e., Evidence, Attestation Results, Endorsements, Reference Values, and Policies) are end-to-end protected based on the role interaction </ins> context.  For example, if an Attester produces Evidence that is relayed through some other entity that doesn't implement the Attester or the intended Verifier roles, then the relaying entity should not

rebased.
` The first sentence seems to say ‘you can do whatever you want’, but the second seems to say “you should sign the messages” This doesn’t seem to be about integrity; it says Evidence must be confidential. Is that actually a requirement?
I don't see where it says RATS messages have to be confidential. 'end-to-end' means between RATS roles. Which can be achieved at different nesting levels; where nesting is interpreted to mean nesting in the message (data) layers. Summary - I don't see a problem with the proposed text.
I am inclined to agree with Ned here, but we could change the first line, while we're at it. The reuse of the word "protected" used in the 1st sentence in the 2nd sentence now might make it more clear that this message protection can happen on many layers.
Ok but this PR merges into the branch instead of master. Recommend rebasing on master so that order of merge doesn't matter.


Question: ""index"" (index-section) <del> ""manifest"" (manifest-section) </del> ""critical"" (critical-section) ""responses"" (responses-section)

This PR removes the manifest section. The motivation is to factor the "core" Web Bundles specification to include just the minimal amount needed to support cases like subresource loading, which does not need a manifest. This and other removed sections can be defined in other documents in the future. Adapted from URL
We might want to make sure the impact of removing manifest section from the bundle format on the chromium. NAME NAME Does Chrome have any usages of manifest section? It seems doesn't use it, however, I am wondering whether there is existing use case for that, I am not aware of.
I never really understood the motivation of this section, since the primary URL response can contain a header pointing to the manifest.
Imagine the situation of application distribution, it is very useful to have a manifest section. For example, we can display the application icon without parsing the HTML of the primary URL. But I agree that the manifest section can be outside the scope of the "core" bundle specification. So removing it from the core spec looks good to me.
LGTM (just for record). Thanks for working on this.


Question: If the Protocol Stack includes a transport protocol that supports multipath connectivity, an update to the available paths should inform the Protocol Instance of the new set of paths that are <del> permissible based on the Path Selection Properties passed by the </del> <ins> permissible based on the Selection Properties passed by the </ins> application.  A multipath protocol can establish new subflows over new paths, and should tear down subflows over paths that are no longer available.  If the Protocol Stack includes a transport

Several small updates, mostly to clean things up a bit, and align property names and such.
NAME - I think you're wrong: my understanding (and also the way the text is written - otherwise we'd have to change it in the API draft) was that Connection Properties can (and should) also be set on Preconnections, to give as much input as possible for Connection establishment. In the API draft, the Selection Properties in Section 5.2 can only be used on Preconnections: you can't ask for congestion control after establishment. You can't say that you'd rather have multistreaming support after establishment. But that doesn't exclude Connection properties from being usable earlier. Required minimum checksum coverage could influence choosing UDP-Lite vs. UDP. Bounds on Send or Receive Rate could influence the interface choice. The capacity profile could influence various things (and no, there isn't a matching Selection Property now - there is a per-Message override). So... I think that either you're wrong, or I'm missing something and the API draft heavily lags behind a decision that was made. I hope not!
NAME The API drafts says: I interpret this as only the Selection Properties influence selection and the Connection properties are used to further configure the connections according to user preferences. Otherwise what is the difference between them?
If you interpret it as you do, I think the text isn't clear enough (indeed it isn't super clear - in particular, "eventually established" is misleading IMO). Though, note that it says that Connection properties can also be used later. Regarding the difference between them: Selection Properties only make sense for Preconnections.
NAME - sorry lost this thread. But I saw that you have started cleaning up some Connection properties that had mixed Connection and Selection properties up in the API draft. Does it mean that we are now in synch and agree that only Selection properties are used in the selection and Connection properties are used for configuration (both during establisment and also after the connection setup).
NAME the other PR means nothing about what I said here: it only tried to address issue which is about a wording inconsistency in a specific property. You say that Connection properties can also be used during establishment - if you agree with allowing this, then why not allow to configure them as early as possible and allow them to influence selection?


Question: If the Protocol Stack includes a transport protocol that supports multipath connectivity, an update to the available paths should inform the Protocol Instance of the new set of paths that are <del> permissible based on the Path Selection Properties passed by the </del> <ins> permissible based on the Selection Properties passed by the </ins> application.  A multipath protocol can establish new subflows over new paths, and should tear down subflows over paths that are no longer available.  If the Protocol Stack includes a transport

What's bad about having more information available that can guide the selection process?
NAME the problem is that the Connection properties are not expressed in a way suitable for selection. If they should also be used for Selection they would have to be reworked to be of type Preference. Otherwise I do not know what they mean for selection. What does it mean if I pick say a particular connection group transmission scheduler? Is it required or preferred? Most connection properties also do not look very useful to me for selection so in case there are some we need I think it would be simpler to just define a matching selection property.
NAME we're only discussing whether it's allowed to use them as additional input or not. I agree, some (like the scheduler choice) don't seem useful, but some do... generally we may not have good guidance on how they should be used by an implementation, but giving the system freedom to use as many inputs as possible is probably a good thing. Regarding the type, require/prefer//ignore/avoid/prohibit obviously works fine for a "wishlist" of boolean character: having something, or not having it. The selection properties are generally like that - except "Interface Instance or Type" and "Provisioning Domain Instance or Type" which are, well... wishlist-collections. Consider the capacity profile. Surely configuring this early can be useful input - e.g. if someone picks low latency / interactive, you may even want to put this traffic on a specific network interface! But if you'd want to make a copy of the capacity profile as a "proper" selection property, how would you do it? Apply require/prefer/ignore/avoid/prohibit for each of its values? Then I could say "prefer" low latency/non-interactive but "avoid" low latency/non-interactive, which would surely be odd. Apply the qualifier to the whole thing? Then it's about, e.g. "avoiding" to use a capacity profile at all. That's odd as well. I think it's in the nature of the current selection properties that they merely say "I want to be able to do this, and this is how important it is to me", which is different from configuring something. That's also why, as written, they simply wouldn't work for later connection configuration.


Question: If the Protocol Stack includes a transport protocol that supports multipath connectivity, an update to the available paths should inform the Protocol Instance of the new set of paths that are <del> permissible based on the Path Selection Properties passed by the </del> <ins> permissible based on the Selection Properties passed by the </ins> application.  A multipath protocol can establish new subflows over new paths, and should tear down subflows over paths that are no longer available.  If the Protocol Stack includes a transport

Connection properties really are about configuring something, but I still say that being able to use them as early input is good. I agree that the implementation isn't super clear as they don't come with a require/prefer/... etc. qualifier, but then we just offer some freedom to implementers.
NAME I just pushed a commit that updates the selection and connection properties text, removing "connection" almost everywhere, but adding a disclaimer in the beginning that says that connection properties should be configured as early as possible because they can influence decisions made by the implementation, and "In the remainder of this document, we only refer to Selection Properties because they are the more typical case." Frankly I'm not sure this is better... but it does remove most of the "selection and connection" double mentions that you pointed out.
Fixed up branch building and resolved merge conflicts. I'll merge this in later today before the posting deadline.
Cool thanks! Sorry if I messed something up
As discussed in
Thank you for updating this – looks good! just needs s/send-params/msg-properties/ and merging


Question: defined. The protocol must use a secure transport that meets the <del> requirements for modern https://. </del> <ins> requirements for modern HTTPS. </ins> 4.1.

I think that we should specify behaviour for truncated responses with the TC bit more clearly. Right now the text is a little vague. There seem to be three options: mandate the generation of an HTTP error mandate the forwarding of the truncated response explicitly allow either forbid the use of truncated responses and recommend fallback to TCP if the DNS API server is just making DNS requests to another server I think that the draft current vacilates in the direction of 3, but I tend to like 1 or 4. Choosing 4 wouldn't be consistent with the dnsop DNS-over-HTTP draft using DOH though.
is the right answer, so the text should just be stronger about it. If DOH requires or , that means that the DNS server code will need to be heavily reworked to capture these from going out, which seems pointless. DOH clients can act like normal stubs: either they do or don't know about truncation and TC.
I agree - I don't think doh needs to behave differently here than any other datagram based client - i.e. its not a transport error. NAME can you do a pr to clarify?
Will do.


Question: Additionally to the previous section, the following applies when Observe is supported. <del> Observe allows re-registration of observations (see 3.3.1 of RFC7641).  A server receiving an Observe registration identical to a previously stored one (including Partial IV and Token) SHALL treat it as valid and reply with the last notification sent. </del> <ins> 7.4.1.1. </ins> A client receiving a notification SHALL compare the Partial IV of a received notification with the Notification Number associated to that <del> Observe registration.  Observe reordering MUST be linked to OSCORE's ordering of notifications.  The client MAY do so by copying the least significant bytes of the Partial IV into the Observe option, before passing it to CoAP processing.  If the verification of the response succeeds, and the received Partial IV was greater than the </del> <ins> Observe registration.  The ordering of notifications after OSCORE processing MUST be aligned with the Partial IV.  The client MAY do so by copying the least significant bytes of the Partial IV into the Observe option, before passing it to CoAP processing.  The client MAY ignore an Outer Observe option value.  If the verification of the response succeeds, and the received Partial IV was greater than the </ins> Notification Number, then the client SHALL update the corresponding Notification Number with the received Partial IV.  The client MUST stop processing notifications with a Partial IV which has been

This PR should (hopefully) conclude the main rewrite of Observe which was triggered by the security analysis and additional reviews of Observe. It should (hopefully) now be clear what part of the Observe related processing can be omitted in case Observe is not supported or in case intermediaries are not used. A new appendix E is covering the latter case.


Question: one way; all other characters are unescaped. Note: Normalized Paths are Singular Queries, but not all Singular <del> Queries are Normalized Paths.  For example, "$[-3]" is a Singular Query, but is not a Normalized Path.  The Normalized Path equivalent </del> <ins> Queries are Normalized Paths.  For example, "$[-3]" is a singular query, but is not a Normalized Path.  The Normalized Path equivalent </ins> to "$[-3]" would have an index equal to the array length minus "3". (The array length must be at least "3" if "$[-3]" is to identify a node.)

Also, delete a term which is used only in the definition of the next term. Fixes URL
I only found the two occurrences you suggested changing. If there are others, please let me know!
Sometimes the spec uses "Singular Query" and sometimes "singular query". We should be consistent. (If we decide to use lower case, it's probably best to address this issue after PR has been merged, since that PR adds some usages of "Singular Query".) Also, there is one instance of "Logical context", which I think would be better uncapitalised ("logical context").
Thanks.


Question: obtains a token at time T2, a colluding issuer and origin can link this to the same client if T2 is unique to the client.  This linkability is less feasible as the number of issuance events at time <del> T2 increases.  Depending on the "max-age" token challenge attribute, </del> <ins> T2 increases.  Depending on the "max-age" token challenge parameter, </ins> clients MAY try to augment the time between getting challenged then redeeming a token so as to make this sort of linkability more difficult.  For more discussion on correlation risks between token

The document refers to authentication scheme attributes throughout; the term from HTTP is 'parameters'. Also, both the challenge and credentials definitions should say what to do with unrecognised parameters.


Question: Defaults are 0x01 for the endpoint initially being client, and 0x00 for the endpoint initially being server <ins> Master Salt Default is the empty string </ins> Key Derivation Function (KDF) Default is HKDF SHA-256

, and
This goes against Jim's wish to have things in bits rather than bytes... But HKDF uses octets and to combine the two parameters as wanted by Ludwig, they need the same unit.
Fixed in branch v-02
OSCOAP refers to HKDF [RFC5869], but it not clearly defined how the parameters map to HKDF-Extract and HKDF-Expand. E.g. IKM. Salt should be made optional.
In section 3.2.1. outlen is defined as "the key/IV size of the AEAD algorithm" and outputlength as "is the size of the AEAD key/IV in bytes encoded as an 8-bit unsigned integer" Isn't that essentially the same?
I just created a v-02 branch for the next update. I'll make an update as soon as possible trying to address this.
Fixed in brach v-02


Question: ODCIL: The original destination connection ID length.  Tokens in NEW_TOKEN frames MUST set this field to zero. <del> Original Destination Connection ID: This is copied from the field in the client Initial packet. </del> <ins> RSCIL: The retry source connection ID length.  Tokens in NEW_TOKEN frames MUST set this field to zero. Original Destination Connection ID: The server or Retry Service copies this from the field in the client Initial packet. Retry Source Connection ID: The server or Retry service copies this from the Source Connection ID of the Retry packet. </ins> Client IP Address: The source IP address from the triggering Initial packet.  The client IP address is 16 octets.  If an IPv4 address, the

After thinking it through, various XOR schemes were extremely vulnerable to manipulation, so I went with a brute force approach.
The server now needs to include this field. For the no-shared state service, we just need language that the Retry service needs to encode enough information validate the packet DCID as well and drop if it fails validation. If it does, the server MUST use the packet DCID in the retrysourceconnection_id TP. For the shared state service, the retry source connection ID is going to have to be in the token. We might be able to compress this by xoring some fields; I'll think about it.


Question: 3.8. <del> A Normalized Path is a JSONPath with restricted syntax that identifies a node by providing a query that results in exactly that node.  For example, the JSONPath expression "$.book[?(@.price<10)]" could select two values with Normalized Paths "$['book'][3]" and "$['book'][5]".  For a given JSON value, there is a one to one correspondence between the value's nodes and the Normalized Paths that identify these nodes.  Note that there is precisely one Normalized Path that identifies each node. A JSONPath implementation may output Normalized Paths instead of, or in addition to, the values identified by these paths. Since bracket notation is more general than dot notation, it is used to construct Normalized Paths.  Single quotes are used to delimit string member names.  This reduces the number of characters that need escaping when Normalized Paths appear as strings (which are delimited with double quotes) in JSON texts. </del> <ins> A Normalized Path is a canonical representation of the identity of a node in a value.  Specifically, a Normalized Path is a JSONPath query with restricted syntax (defined below), e.g., "$['book'][3]", which when applied to the value results in a nodelist consisting of just the node identified by the Normalized Path.  Note that a Normalized Path represents the identity of a node .  There is precisely one Normalized Path identifying any particular node in a value. A canonical representation of a nodelist is as a JSON arrays of strings, where the strings are Normalized Paths. Normalized Paths provide a predictable format that simplifies testing and post-processing of nodelists, e.g., to remove duplicate nodes. Normalized Paths are used in this document as result paths in examples. Normalized Paths use the canonical bracket notation, rather than dot notation. Single quotes are used to delimit string member names.  This reduces the number of characters that need escaping when Normalized Paths appear in double quote delimited strings, e.g., in JSON texts. </ins> Certain characters are escaped, in one and only one way; all other characters are unescaped. <del> Normalized Paths are Singular Paths.  Not all Singular Paths are Normalized Paths: "$[-3]", for example, is a Singular Path, but not a Normalized Path.  The Normalized Path equivalent to "$[-3]" would have an index equal to the array length minus "3".  (The array length must be at least "3" if "$[-3]" is to identify a node.) </del> <ins> Note: Normalized Paths are Singular Paths, but not all Singular Paths are Normalized Paths.  For example, "$[-3]" is a Singular Path, but is not a Normalized Path.  The Normalized Path equivalent to "$[-3]" would have an index equal to the array length minus "3".  (The array length must be at least "3" if "$[-3]" is to identify a node.) </ins> Since there can only be one Normalized Path identifying a given node, the syntax stipulates which characters are escaped and which are not. So the definition of "normal-hexchar" is designed for hex escaping of characters which are not straightforwardly-printable, for example <del> U+000B LINE TABULATION, but for which no standard JSON escape such as "n" is available. </del> <ins> U+000B LINE TABULATION, but for which no standard JSON escape, such as "n", is available. </ins> 3.8.1.

I welcome this ... thanks.
From the side line: Do we need to add description of behavior (with a qualifier) to motivate the truly welcome attributes of the ?
A Normalized Path is just a particular kind of JSONPath query. Its only behaviour is to identify a node within the tree of nodes in a value. Or did you have some other behaviour in mind?
Oh, of course, but that formulation had never occurred to me, and it's useful. If it's not in the spec, it should be.
I meant the first of the two sentences: Here we describe the behavior of an implementation (output as response to an unspecified request that triggers the former). I just wonder if this section is a good place to describe a part of a protocol, when the topics are a) the "projection" itself and b) potential benefits (all from a data perspective).
Well, we describe the nature of what it is to implement JSONPath. Generally, in a protocol, you not only need to prescribe what is on the wire, but also what it means. That is only ever in the implementation. That doesn't mean that it describes the behavior of an implementation. E.g., in TCP, the byte stream that is transported by the protocol only ever happens in the implementation. Nothing on the wire reflects this byte stream. But describing that byte stream as the underlying model of TCP is rightly not criticized as "describing the behavior of an implementation".
The penny has just dropped: you are questioning the need for such a description rather than asking for more of the same! I agree with NAME response.
I think an important aspect that this is missing is that normalized paths are contexted to the JSON data that was queried; whereas singular paths exist independently, as does any other path. For example, the path (used in the text) is singular and can rightfully exist on its own. However it can't be normalized without querying JSON data. Once queried, the resulting normalized paths can be different based on the data. yields a normalized path of for the value yields a normalized path of for the value .
This text isn't getting into implementation behavior at all. It's specifying output and allowing for options.
Well, unforced ambiguous behavior then. Specifying output and allowing for (unrequested) options.


Question: 3.8. <del> A Normalized Path is a JSONPath with restricted syntax that identifies a node by providing a query that results in exactly that node.  For example, the JSONPath expression "$.book[?(@.price<10)]" could select two values with Normalized Paths "$['book'][3]" and "$['book'][5]".  For a given JSON value, there is a one to one correspondence between the value's nodes and the Normalized Paths that identify these nodes.  Note that there is precisely one Normalized Path that identifies each node. A JSONPath implementation may output Normalized Paths instead of, or in addition to, the values identified by these paths. Since bracket notation is more general than dot notation, it is used to construct Normalized Paths.  Single quotes are used to delimit string member names.  This reduces the number of characters that need escaping when Normalized Paths appear as strings (which are delimited with double quotes) in JSON texts. </del> <ins> A Normalized Path is a canonical representation of the identity of a node in a value.  Specifically, a Normalized Path is a JSONPath query with restricted syntax (defined below), e.g., "$['book'][3]", which when applied to the value results in a nodelist consisting of just the node identified by the Normalized Path.  Note that a Normalized Path represents the identity of a node .  There is precisely one Normalized Path identifying any particular node in a value. A canonical representation of a nodelist is as a JSON arrays of strings, where the strings are Normalized Paths. Normalized Paths provide a predictable format that simplifies testing and post-processing of nodelists, e.g., to remove duplicate nodes. Normalized Paths are used in this document as result paths in examples. Normalized Paths use the canonical bracket notation, rather than dot notation. Single quotes are used to delimit string member names.  This reduces the number of characters that need escaping when Normalized Paths appear in double quote delimited strings, e.g., in JSON texts. </ins> Certain characters are escaped, in one and only one way; all other characters are unescaped. <del> Normalized Paths are Singular Paths.  Not all Singular Paths are Normalized Paths: "$[-3]", for example, is a Singular Path, but not a Normalized Path.  The Normalized Path equivalent to "$[-3]" would have an index equal to the array length minus "3".  (The array length must be at least "3" if "$[-3]" is to identify a node.) </del> <ins> Note: Normalized Paths are Singular Paths, but not all Singular Paths are Normalized Paths.  For example, "$[-3]" is a Singular Path, but is not a Normalized Path.  The Normalized Path equivalent to "$[-3]" would have an index equal to the array length minus "3".  (The array length must be at least "3" if "$[-3]" is to identify a node.) </ins> Since there can only be one Normalized Path identifying a given node, the syntax stipulates which characters are escaped and which are not. So the definition of "normal-hexchar" is designed for hex escaping of characters which are not straightforwardly-printable, for example <del> U+000B LINE TABULATION, but for which no standard JSON escape such as "n" is available. </del> <ins> U+000B LINE TABULATION, but for which no standard JSON escape, such as "n", is available. </ins> 3.8.1.

For instance when the SomeTool processor outputs a number 42 and the options are that it represents any base in which the symbols are generally valid (per consensus) to me would rather raise questions than answer them. I would expect these complication (extra dimensions) less inside a format but more in a "processor" role or protocol description. The latter describing expected behavior within the dynamics of some interchange. I used the term without caution. Sorry for that. In my reading of the sentence we discuss about, the consumer of such a result has to look elsewhere to find out what the processor provides as result, right? That is our normal task as tool users. However, I think we better try to not bring in such ambiguities without noting the reason outside of our mandate to change. Maybe note, that existing processors (or however we like to call these providers of jsonpath responses) display mixed behaviors (what you call options). Makes sense? If not, sorry for the noise.
Well, we do say: I wouldn't go so far to say that the Normalized Path is "contexted". You need the value to compute the Normalized Path from the query, but after that, it doesn't require context to apply it (well, they are meant to be applied to that value, but they are regular JSONPath queries). With IETF 115 raging and Glyn being offline for a couple of days, we'll probably not respond very fast the next few days; I think good points are being made here even it is not always clear how to modify the text further to fully reflect them.
I believe the PR now makes this property of Normalized Paths clear. (I'd prefer not to labour the example.)
NAME I have attempted to address your concern by making the following general statement (suggested by NAME Normalized Paths. A nodelist is defined as follows (in the Terminology section): From this, it is clear that an implementation of JSONPath may output a nodelist as a JSON array of strings, where the strings are Normalized Paths. So I have deleted the following statements, which seemed to be causing confusion: Normalized Paths instead of, or in addition to, the values identified by these paths. For example, the JSONPath expression could select two values and an implementation could output the Normalized Paths and .


Question: 3.8. <del> A Normalized Path is a JSONPath with restricted syntax that identifies a node by providing a query that results in exactly that node.  For example, the JSONPath expression "$.book[?(@.price<10)]" could select two values with Normalized Paths "$['book'][3]" and "$['book'][5]".  For a given JSON value, there is a one to one correspondence between the value's nodes and the Normalized Paths that identify these nodes.  Note that there is precisely one Normalized Path that identifies each node. A JSONPath implementation may output Normalized Paths instead of, or in addition to, the values identified by these paths. Since bracket notation is more general than dot notation, it is used to construct Normalized Paths.  Single quotes are used to delimit string member names.  This reduces the number of characters that need escaping when Normalized Paths appear as strings (which are delimited with double quotes) in JSON texts. </del> <ins> A Normalized Path is a canonical representation of the identity of a node in a value.  Specifically, a Normalized Path is a JSONPath query with restricted syntax (defined below), e.g., "$['book'][3]", which when applied to the value results in a nodelist consisting of just the node identified by the Normalized Path.  Note that a Normalized Path represents the identity of a node .  There is precisely one Normalized Path identifying any particular node in a value. A canonical representation of a nodelist is as a JSON arrays of strings, where the strings are Normalized Paths. Normalized Paths provide a predictable format that simplifies testing and post-processing of nodelists, e.g., to remove duplicate nodes. Normalized Paths are used in this document as result paths in examples. Normalized Paths use the canonical bracket notation, rather than dot notation. Single quotes are used to delimit string member names.  This reduces the number of characters that need escaping when Normalized Paths appear in double quote delimited strings, e.g., in JSON texts. </ins> Certain characters are escaped, in one and only one way; all other characters are unescaped. <del> Normalized Paths are Singular Paths.  Not all Singular Paths are Normalized Paths: "$[-3]", for example, is a Singular Path, but not a Normalized Path.  The Normalized Path equivalent to "$[-3]" would have an index equal to the array length minus "3".  (The array length must be at least "3" if "$[-3]" is to identify a node.) </del> <ins> Note: Normalized Paths are Singular Paths, but not all Singular Paths are Normalized Paths.  For example, "$[-3]" is a Singular Path, but is not a Normalized Path.  The Normalized Path equivalent to "$[-3]" would have an index equal to the array length minus "3".  (The array length must be at least "3" if "$[-3]" is to identify a node.) </ins> Since there can only be one Normalized Path identifying a given node, the syntax stipulates which characters are escaped and which are not. So the definition of "normal-hexchar" is designed for hex escaping of characters which are not straightforwardly-printable, for example <del> U+000B LINE TABULATION, but for which no standard JSON escape such as "n" is available. </del> <ins> U+000B LINE TABULATION, but for which no standard JSON escape, such as "n", is available. </ins> 3.8.1.

(I'm not sure whether this will be acceptable to the other reviewers, so I'm going to leave the PR open until they have had a chance to review the latest version.)
Normalizing paths? What does that mean? There is no concept of "normalizing" arbitrary paths, it's pointless, there is no suggestion of that in Goessner's original article, or anywhere else that I'm aware of.
NAME Not sure if you've seen the final form of this PR, but I'm going to merge it to close off the discussion threads. We can adjust the section later if necessary.
URL begs the question of whether nodelists should have a normalized form. This would improve the interoperation, predictability, etc. of JSONPath implementations that output nodelists. Without this, JSONPath implementations which output nodelists would likely choose multiple different ways of representing nodelists. The proposal is for a Normalized Nodelist to consist of a possibly empty, whitespace separated list of Normalized Paths as in the following ABNF: Note: this proposal does not provide a normalized form for output from JSONPath implementations that output both nodelists and values.
good approach ... I would prefer a comma separated list, being able to be consumed as a JSON array without further modification ...
ohh ... and the URL as JSON strings, i.e.
I don't think we want to do this. This is not a JSONPath query, but a structure built from that. I'd like to leave structure building to JSON entirely. We are not defining the syntax of JSON, and we should avoid falling into the restatement antipattern trap. So yes, a nodelist might look like , but not because we say so, but because that is JSON syntax. We would simply say nodelists are canonically represented as JSON arrays of strings, where the strings are normatlizedpaths.
yes ... that's even better and pragmatical.
Why do they exist? The spec says nothing on the subject. If we don't have something convincing to say, why not remove them? I know we discussed this before, but as I was reading this with fresh eyes I was thinking "There's a lot of stuff here but why bother?"
The normalized path was to be used in the output. I don't think there was any other use for them.