jiebi/CodeConvo huggingface dataset:
initially issued. At a high level, the Privacy Pass architecture consists of two <del> protocols: issuance and redemption.  The issuance protocol runs between an endpoint referred to as a Client and two functions in the Privacy Pass architecture: Attestation and Issuance.  These two network functions can be implemented by the same protocol participant, but can also be implemented separately.  The entity that implements Issuance, referred to as the Issuer, is responsible for issuing tokens in response to requests from Clients.  The entity that implements Attestation, referred to as the Attester, is responsible for attesting to properties about the Client for which tokens are issued.  The Issuer needs to be trusted by the server that later redeems the token.  Attestation can be performed by the Issuer or by an Attester that is trusted by the Issuer.  Clients might prefer to select different Attesters, separate from the Issuer, to be able to use preferred authentication methods or to improve privacy by not directly communicating with an Issuer.  Depending on the attestation, Attesters can store state about a Client, such as the number of overall tokens issued thus far.  As an example of an issuance protocol, in the original Privacy Pass protocol PPEXT, tokens were only issued to Clients that solved CAPTCHAs.  In this context, the Attester attested that some client solved a CAPTCHA and the resulting token produced by the Issuer was proof of this fact. The redemption protocol runs between Client and Origin (server).  It allows Origins to challenge Clients to present one or more tokens for </del> <ins> protocols: issuance and redemption.  The redemption protocol AUTHSCHEME runs between Client and Origin (server).  It allows Origins to challenge Clients to present one or more tokens for </ins> authorization.  Depending on the type of token, e.g., whether or not it can be cached, the Client either presents a previously obtained <del> token or invokes the issuance protocol to acquire one for authorization. The issuance and redemption protocols operate in concert as shown in the figure below. </del> <ins> token or invokes an issuance protocol, such as ISSUANCE, to acquire a token to present as authorization. </ins> This document describes requirements for both issuance and redemption <del> protocols.  It also provides recommendations on how the architecture should be deployed to ensure the privacy of clients and the security of all participating entities. The privacypass working group is working on AUTHSCHEME as an instantiation of a redemption protocol and ISSUANCE as an instantiation of the issuance protocol. </del> <ins> protocols and how they interact.  It also provides recommendations on how the architecture should be deployed to ensure the privacy of clients and the security of all participating entities. </ins> 2.
Attester: An entity that attests to properties of Client for the purposes of token issuance. <ins> Redemption context: The interactions and set of information shared between the Client and Origin. Issuance context: The interactions and set of information shared between the Client, Attester, and Issuer. Attestation context: The interactions and set of information shared between the Client and Attester only, for the purposes of attesting the vailidity of the Client. </ins> 3. The Privacy Pass architecture consists of four logical entities - <del> Client, Origin, Issuer, and Attester - that work in concert as shown in introduction for token issuance and redemption.  This section describes the purpose of token issuance and redemption and the requirements therein on the relevant participants. </del> <ins> Client, Origin, Issuer, and Attester - that work in concert as for token issuance and redemption.  This section describes the purpose of token issuance and redemption and the requirements on the relevant participants. The typical interaction flow for Privacy Pass tokens uses the following steps: A Client interacts with an Origin by sending an HTTP request.  The Origin sends an HTTP response that contains a token challenge that indicates a specific Issuer to use.  Note that the request might be made as part of accessing a resource normally, or with the specific intent of triggering a token challenge. If the Client already has a token available that satisfies the token challenge, it can skip to step 6 and redeem its token. Otherwise, it invokes the issuance protocol to request a token from the designated Issuer. The first step in the issuance protocol is attestation. Specifically, the Attester performs attestation checks on the Client.  These checks could be proof of solving a CAPTCHA, device trust, hardware attestation, etc (see attester). If attestation succeeds, the client creates a Token Request to send to the designated Issuer (generally via the Attester).  The Attester and Issuer might be functions on the same server, depending on the deployment model (see deployment).  Depending on the details of Attestation, the Client can send the Token Request to the Attester alongside any attestation information.  If attestation fails, the Client receives an error and issuance aborts without a token. The Issuer generates a Token Response based on the Token Request, which is returned to the Client (generally via the Attester). Upon receiving the Token Response, the Client computes a token from the token challenge and Token Response.  This token can be validated by anyone with the per-Issuer key, but cannot be linked to the content of the Token Request or Token Response. If the Client has a token, it includes it in a subsequent HTTP request to the Origin, as authorization.  This token is sent only once.  The Origin validates that the token was generated by the expected Issuer and has not already been redeemed for the corresponding token challenge.  If the Client does not have a token, perhaps because issuance failed, the client does not reply to the Origin's challenge with a new request. </ins> 3.1.
timestamp of the event, Client visible information (including the IP address), and the Origin name. <del> The challenge controls the type of token that the Origin will accept for the given resource.  As described in AUTHSCHEME, there are a number of ways in which the token may vary, including: </del> <ins> The challenge provides the client with the information necessary to obtain tokens that the server might subsequently accept (in this context).  As described in AUTHSCHEME, there are a number of ways in which the token may vary, including: </ins> Issuance protocol.  The token identifies the type of issuance protocol required for producing the token.  Different issuance
3.2.1. <del> Attestation is an important part of the issuance protocol. Attestation is the process by which an Attester bears witness to, confirms, or authenticates a Client so as to verify a property about the Client that is required for Issuance.  Examples of attestation properties include, though are not limited to: Capable of solving a CAPTCHA.  Clients that solve CAPTCHA challenges can be attested to have this capability for the purpose of being ruled out as a bot or otherwise automated Client. Client state.  Clients can be associated with state and the attester can attest to this state.  Examples of state include the number of issuance protocol invocations, the Client's geographic region, and whether the client has a valid application-layer account. Trusted device.  Some Clients run on trusted hardware that are capable of producing device-level attestation statements. Each of these attestation types has different security properties. For example, attesting to having a valid account is different from attesting to running on trusted hardware.  In general, minimizing the set of attestation formats helps minimize the amount of information leaked through a token. </del> <ins> Attestation is an important part of the issuance protocol.  In Privacy Pass, attestation is the process by which an Attester bears witness to, confirms, or authenticates a Client so as to verify a property about the Client that is required for Issuance.  RFC9334 describes an architecture for attestation procedures.  Using that architecture as a conceptual basis, Clients are RATS attesters that produce attestation evidence, and Attesters are RATS verififiers that appraise the validity of attestation evidence. The type of attestation procedure is a deployment-specific option and outside the scope of the issuance protocol.  Example attestation procedures are below. Solving a CAPTCHA.  Clients that solve CAPTCHA challenges can be attested to have this capability for the purpose of being ruled out as a bot or otherwise automated Client. Presenting evidence of Client device validity.  Some Clients run on trusted hardware that are capable of producing device-level attestation evidence. Proving properties about Client state.  Clients can be associated with state and the Attester can verify this state.  Examples of state include the Client's geographic region and whether the Client has a valid application-layer account. Attesters may support different types of attestation procedures.  A type of attestation procedure is also referred as an attestation format. In general, each attestation format has different security properties.  For example, attesting to having a valid account is different from attesting to running on trusted hardware.  In general, minimizing the set of attestation formats helps minimize the amount of information leaked through a token. </ins> Each attestation format also has an impact on the overall system privacy.  Requiring a conjunction of attestation types could decrease
If the Client already has a token available that satisfies the token challenge, e.g., because the Client has a cache of previously issued tokens, it can skip to step-redemption and <del> redeem its token.  Otherwise, it invokes the issuance protocol to request a token from the designated Issuer. The first step in the issuance protocol is attestation. Specifically, the Attester performs attestation checks on the Client.  These checks could be proof of solving a CAPTCHA, device trust, hardware attestation, etc (see attester). If attestation succeeds, the client creates a Token Request to send to the designated Issuer (generally via the Attester).  The Attester and Issuer might be functions on the same server, depending on the deployment model (see deployment).  Depending on the details of Attestation, the Client can send the Token Request to the Attester alongside any attestation information.  If attestation fails, the Client receives an error and issuance aborts without a token. </del> <ins> redeem its token. If the Client does not have a token available and decides it wants to obtain one (or more) bound to the token challenge, it then invokes the issuance protocol.  As a prerequisite to the issuance protocol, the Client runs the deployment specific attestation process that is required for the designated Issuer.  Client attestation can be done via proof of solving a CAPTCHA, checking device or hardware attestation validity, etc; see attester for more details. If the attestation process completes successfully, the client creates a Token Request to send to the designated Issuer (generally via the Attester).  The Attester and Issuer might be functions on the same server, depending on the deployment model (see deployment).  Depending on the attestation process, it is possible for attestation to run alongside the issuance protocol, e.g., where Clients send necessary attestation information to the Attester along with their Token Request.  If the attestation process fails, the Client receives an error and issuance aborts without a token. </ins> The Issuer generates a Token Response based on the Token Request, which is returned to the Client (generally via the Attester).
Issuer-Client unlinkability.  This is similar to Origin-Client unlinkability in that a Client in an issuance context is indistinguishable from any other Client that might use the same <del> issuance context.  The set of Clients that share the same redemption context is referred to as a redemption anonymity set. </del> <ins> issuance context.  The set of Clients that share the same issuance context is referred to as an issuance anonymity set. </ins> Attester-Origin unlinkability.  This is similar to Origin-Client and Issuer-Client unlinkability.  It means that given two attestation contexts, the Attester cannot determine if both contexts correspond to the same Origin or two different Origins. The set of Clients that share the same attestation context is <del> referred to as an anonymity set. </del> <ins> referred to as an attestation anonymity set. </ins> By ensuring that different contexts cannot be linked in this way, only the Client is able to correlate information that might be used
Origins.  Implementing mitigations discused in deployment and privacy is therefore necessary to ensure that Privacy Pass offers meaningful privacy improvements to end-users. <ins> 7.1. Depending on the Origin's token challenge, Clients can request and cache more than one token using an issuance protocol.  Cached tokens help improve privacy by separating the time of token issuance from the time of token redemption, and also allow Clients to reduce the overhead of receiving new tokens via the issuance protocol. As a consequence, Origins that send token challenges which are compatible with cached tokens need to take precautions to ensure that tokens are not replayed.  This is typically done via keeping track of tokens that are redeemed for the period of time in which cached tokens would be accepted for particular challenges. Moreover, since tokens are not intrinsically bound to Clients, it is possible for malicious Clients to collude and share tokens in a so- called "hoarding attack."  As an example of this attack, many distributed Clients could obtain cacheable tokens and them share them with a single Client to redeem in a way that would violate an Origin's attempt to limit tokens to any one particular Client. Depending on the deployment model, it can be possible to detect these types of attacks by comparing issuance and redemption contexts; for example, this is possible in the Joint Origin and Issuer model. </ins>
3.4.1. <del> Attestation is an important part of the issuance protocol.  In Privacy Pass, attestation is the process by which an Attester bears witness to, confirms, or authenticates a Client so as to verify a property about the Client that is required for Issuance.  Clients explicitly trust Attesters to perform attestation correctly and in a way that does not violate their privacy. </del> <ins> In Privacy Pass, attestation is the process by which an Attester bears witness to, confirms, or authenticates a Client so as to verify properties about the Client that are required for Issuance.  Issuers trust Attesters to perform attestation correctly. </ins> RFC9334 describes an architecture for attestation procedures.  Using that architecture as a conceptual basis, Clients are RATS attesters
minimizing the set of supported attestation procedures helps minimize the amount of information leaked through a token. <del> Each attestation procedure also has an impact on the overall system privacy.  Requiring a conjunction of attestation types could decrease the overall anonymity set size.  For example, the number of Clients that have solved a CAPTCHA in the past day, that have a valid account, and that are running on a trusted device is less than the number of Clients that have solved a CAPTCHA in the past day. Attesters SHOULD not admit attestation types that result in small anonymity sets. </del> <ins> The role of the Attester in the issuance protocol and its impact on privacy depends on the type of attestation procedure, issuance protocol, deployment model.  For instance, requiring a conjunction of attestation procedures could decrease the overall anonymity set size. As an example, the number of Clients that have solved a CAPTCHA in the past day, that have a valid account, and that are running on a trusted device is less than the number of Clients that have solved a CAPTCHA in the past day.  Attesters SHOULD NOT be based on attestation procedures that result in small anonymity sets. Depending on the issuance protocol, the Issuer might learn information about the Origin.  To ensure Issuer-Client unlinkability, the Issuer should be unable to link that information to a specific Client.  For such issuance protocols where the Attester has access to Client-specific information, such as is the case for attestation procedures that involve Client-specific information (such as application-layer account information) or for deployment models where the Attester learns Client-specific information (such as Client IP addresses), Clients trust the Attester to not share any Client- specific information with the Issuer.  In deployments where the Attester does not learn Client-specific information, the Client does not need to explicitly trust the Attester in this regard. </ins> Issuers trust Attesters to correctly and reliably perform attestation.  However, certain types of attestation can vary in value
2. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", <del> "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC2119. </del> <ins> "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 RFC2119 RFC8174 when, and only when, they appear in all capitals, as shown here. </ins> 3. In order to establish a peer-to-peer connection, WebRTC implementations use Interactive Connectivity Establishment (ICE) <del> RFC5245, which attempts to discover multiple IP addresses using </del> <ins> RFC8445, which attempts to discover multiple IP addresses using </ins> techniques such as Session Traversal Utilities for NAT (STUN) RFC5389 and Traversal Using Relays around NAT (TURN) RFC5766, and then checks the connectivity of each local-address-remote-address pair in order
1.3. <del> When RFC8829 was published, inconsistencies regarding BUNDLE RFC8843 operation were identified with regard to both the specification text as well as implementation behavior.  The former concern was addressed via an update to RFC8843.  For the latter concern, it was observed that some implementations implemented the "max-bundle" bundle policy defined in RFC8829 by assuming that bundling had already been negotiated, rather than marking "m=" sections as bundle-only as indicated by the specification.  In order to prevent unexpected changes to applications relying on the pre-standard behavior, the decision was made to deprecate "max-bundle" and instead introduce an identically defined "must-bundle" policy that, when selected, provides the behavior originally specified by RFC8829. </del> <ins> When RFC8829 was published, inconsistencies regarding BUNDLE I- D.ietf-mmusic-rfc8843-bis operation were identified with regard to both the specification text as well as implementation behavior.  The former concern was addressed via an update to I-D.ietf-mmusic- rfc8843-bis.  For the latter concern, it was observed that some implementations implemented the "max-bundle" bundle policy defined in RFC8829 by assuming that bundling had already been negotiated, rather than marking "m=" sections as bundle-only as indicated by the specification.  In order to prevent unexpected changes to applications relying on the pre-standard behavior, the decision was made to deprecate "max-bundle" and instead introduce an identically defined "must-bundle" policy that, when selected, provides the behavior originally specified by RFC8829. </ins> 2.
MUST be zero. The application can specify its preferred policy regarding the use of <del> BUNDLE, the multiplexing mechanism defined in RFC8843.  Regardless of policy, the application will always try to negotiate bundle onto a single transport and will offer a single bundle group across all "m=" sections; use of this single transport is contingent upon the answerer accepting bundle.  However, by specifying a policy from the list below, the application can control exactly how aggressively it will try to bundle media streams together, which affects how it will interoperate with a non-bundle-aware endpoint.  When negotiating with a non-bundle-aware endpoint, only the streams not marked as bundle- only streams will be established. </del> <ins> BUNDLE, the multiplexing mechanism defined in I-D.ietf-mmusic- rfc8843-bis.  Regardless of policy, the application will always try to negotiate bundle onto a single transport and will offer a single bundle group across all "m=" sections; use of this single transport is contingent upon the answerer accepting bundle.  However, by specifying a policy from the list below, the application can control exactly how aggressively it will try to bundle media streams together, which affects how it will interoperate with a non-bundle- aware endpoint.  When negotiating with a non-bundle-aware endpoint, only the streams not marked as bundle-only streams will be established. </ins> The set of available policies is as follows:
RFC8859 groups SDP attributes into different categories.  To avoid unnecessary duplication when bundling, attributes of category IDENTICAL or TRANSPORT MUST NOT be repeated in bundled "m=" sections, <del> repeating the guidance from RFC8843.  This includes "m=" sections for which bundling has been negotiated and is still desired, as well as "m=" sections marked as bundle-only. </del> <ins> repeating the guidance from I-D.ietf-mmusic-rfc8843-bis.  This includes "m=" sections for which bundling has been negotiated and is still desired, as well as "m=" sections marked as bundle-only. </ins> The following attributes, which are of a category other than IDENTICAL or TRANSPORT, MUST be included in each "m=" section:
possible, and media sections will not be marked as bundle-only.  This is by design, but could cause issues in the rare case of sending a subsequent offer as an initial offer to a non-bundle-aware endpoint <del> via Third Party Call Control (3PCC). </del> <ins> via Third Party Call Control (3PCC), as discussed in I-D.ietf-mmusic- rfc8843-bis. </ins> "a=group:LS" attributes are generated in the same way as for initial offers, with the additional stipulation that any lip sync groups that
If the answer contains valid bundle groups, discard any ICE components for the "m=" sections that will be bundled onto the primary ICE components in each bundle, and begin muxing these "m=" <del> sections accordingly, as described in RFC8843. </del> <ins> sections accordingly, as described in I-D.ietf-mmusic-rfc8843-bis. </ins> If the description is of type "answer" and there are still remaining candidates in the ICE candidate pool, discard them.
6. When bundling, associating incoming RTP/RTCP with the proper "m=" <del> section is defined in RFC8843.  When not bundling, the proper "m=" section is clear from the ICE component over which the RTP/RTCP is received. </del> <ins> section is defined in I-D.ietf-mmusic-rfc8843-bis.  When not bundling, the proper "m=" section is clear from the ICE component over which the RTP/RTCP is received. </ins> Once the proper "m=" section or sections are known, RTP/RTCP is delivered to the RtpTransceiver(s) associated with the "m="
RFC4566 is the base SDP specification and MUST be implemented. RFC5764 MUST be supported for signaling the UDP/TLS/RTP/SAVPF <del> RFC5764 and TCP/TLS/RTP/SAVPF I-D.nandakumar-mmusic-proto-iana- </del> <ins> RFC5764 and TCP/DTLS/RTP/SAVPF I-D.nandakumar-mmusic-proto-iana- </ins> registration RTP profiles. RFC5245 MUST be implemented for signaling the ICE credentials and