]> Amazon

crlsa@amazon.com

FullCtl

grizz@20c.com

Meta

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Google

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AS207960 Cyfyngedig

q@as207960.net

BGP peering configuration We propose an API standard for BGP Peering, also known as interdomain interconnection through global Internet Routing. This API offers a standard way to request public (settlement-free) peering, verify the status of a request or BGP session, and list potential connection locations. The API is backed by PeeringDB OIDC, the industry standard for peering authentication. We also propose future work to cover private peering, and alternative authentication methods. About This Document The latest revision of this draft can be found at . Status information for this document may be found at . Source for this draft and an issue tracker can be found at .

Introduction The Peering API is a mechanism that allows networks to automate interdomain interconnection between two Autonomous Systems (AS) through the Border Gateway Protocol 4 (). Using the API, networks will be able to automatically request and accept peering interconnections between Autonomous Systems in public or private scenarios in a time faster than it would take to configure sessions manually. By speeding up the peering turn-up process and removing the need for manual involvement in peering, the API and automation will ensure that networks can get interconnected as fast, reliably, cost-effectively, and efficiently as possible. As a result, this improves end-user performance for all applications using networks interconnection supporting the Peering API.

Business Justification By using the Peering API, entities requesting and accepting peering can significantly improve the process to turn up interconnections by:

• Reducing in person-hours spent configuring peering
• Reducing configuration mistakes by reducing human interaction
• And by peering, reducing network latency through expansion of interconnection relationships

Conventions and Terminology All terms used in this document will be defined here:

Initiator

Network that wants to peer

Receiver

Network that is receiving communications about peering

Configured

peering session that is set up on one side

Established

session is already defined as per BGP-4 specification

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here. These words may also appear in this document in lower case as plain English words, absent their normative meanings.

Audience The Peering API aims to simplify peering interconnection configuration. To that end, the API can be called by either a human or some automation. A network engineer can submit API requests through a client-side tool, and configure sessions by hand or through existing tooling. Alternately, an automated service can request BGP sessions through some trigger or regularly scheduled request (for example, upon joining a new peering location, or through regular polling of potential peers). That automated client can then configure the client sessions through its own tooling. For ease of exchanging peering requests, the authors suggest peers to maintain both a client and a server for the API. Toward the goal of streamlining peering configuration, the authors encourage peers to automate their network configuration wherever possible, but do not require full automation to use this API.

Protocol The Peering API follows the Representational State Transfer () architecture where sessions, locations, and maintenance events are the resources the API represents and is modeled after the OpenAPI standard . Using the token bearer model (), a client application can request to add or remove peering sessions, list potential interconnection locations, and query for upcoming maintenance events on behalf of the AS resource owner.

Example Peering Request Negotiation Diagram of the Peering Request Process | Network 1 | | Identifies need | | Checks details | '-----------------' '-----------------' | v +-------------------+ .-----------------. | Step 4 | | Step 3 | | Network 1 |<-------------------| Network 1 | | gets approval | | Public or | | token | | Private Peering | +-------------------+ '-----------------' | v +-------------------+ +-------------------+ | Step 5 | | Step 6 | | Network 1 finds |------------------->| Network 1 | | common locations | | request peering | +-------------------+ +-------------------+ | v +-------------------+ +--------------------+ | Step 8 | | Step 7 | | Network 2 |<------------------| Network 2 | | accepts or reject | | verifies | | sessions | | credentials | +-------------------+ +--------------------+ / \ / \ / \ Accept Reject \ | \ +-------------------------------+ \ | \ | v | +---------------+ +----------------+ | | Step 9 | | Step 10 | | | Sessions are | | Network 1 or 2 | | | provisioned |--------->| checks session | | | status | | until it is up | | +---------------+ +----------------+ | | | +------------+ | | | v | +------------+ | | Step 11 | | | Process |<----------------------+ | Terminates | +------------+ ]]>

• Step 1 (Human): Network 1 identifies that it would be useful to peer with Network 2 to interchange traffic more optimally.
• Step 2 (Human): Network 1 checks technical and other peering details about Network 2 to check if peering is possible.
• Step 3 (Human): Network 1 decides in type (Public or PNI) of peering and facility.
• Step 4 (API): Network 1 gets approval/token that is authorized to ‘speak’ on behalf of Network 1’s ASN.
• Step 5 (API): Network 1 checks PeeringDB for common places between Network 1 and Network 2; GET /locations
• Step 6 (API): Network 1 request peering with Network 2; POST /add_sessions
• Step 7 (API): Network 2 verifies Network 1 credentials, check requirements for peering.
• Step 8 (API): Network 2 accepts or rejects session(s). API Server gives yes/no for request.
• Step 9 (API): If yes, sessions are provisioned, Networks 1 or Network 2 can check status; API: GET /sessions
• Step 10 (API): API keeps polling until sessions are up
• Step 11 (API): Process Terminates

Example API Flow The diagram below outlines the proposed API flow.

List Locations | | | | Reply with peering locations | | or errors (401, 406, 451, etc.) | |<-----------------------------------------------------------| ]]>

Request session status | | | | Reply with session status | | (200, 404, 202, etc.) | |<-----------------------------------------------------------| ]]>

REQUEST

1. ADD SESSION (CLIENT BATCHED REQUEST)

• The initiator's client provides a set of the following information, where local always refers to the receiver and peer always refers to the initiator:
  • Structure:
    1. Local ASN
    2. Local IP
    3. Peer ASN
    4. Peer IP
    5. Local BGP Role according to
    6. Peer BGP Role according to
    7. Local insert ASN (optional to support route servers)
    8. Peer insert ASN (optional to support route servers)
    9. Local monitoring session (optional to support monitoring systems)
    10. Peer monitoring session (optional to support monitoring systems)
    11. Peer Type (public or private)
    12. Session Secret (optional with encoding agreed outside of this specification)
    13. Location (Commonly agreed identifier of the BGP speaker, e.g. PeeringDB IX lan ID)
• The receiver's expected actions:
  • The server confirms requested clientASN in list of authorized ASNs.
  • Optional: checks traffic levels, prefix limit counters, other desired internal checks. 2. ADD SESSIONS (SERVER BATCHED RESPONSE)
• APPROVAL CASE
  • Server returns a list with the structure for each of the acceptable peering sessions. Note: this structure may also contain additional attributes such as the server generated session ID.
• PARTIAL APPROVAL CASE
  • Server returns a list with the structure for each of the acceptable peering sessions as in the approval case. The server also returns a list of sessions that have not deemed as validated or acceptable to be created. The set of sessions accepted and rejected is disjoint and the join of both sets matches the cardinality of the requested sessions.
• REJECTION CASE
  • Server returns an error message which indicates that all of the sessions requested have been rejected and the reason for it.

CLIENT CONFIGURATION The client then configures the chosen peering sessions asynchronously using their internal mechanisms. The client SHOULD pull and use additional information on the new peering from public sources as required to ensure routing security, e.g., AS-SETs to configure appropriate filters. For every session that the server rejected, the client removes that session from the list to be configured.

SERVER CONFIGURATION The server configures all sessions that are in its list of approved peering sessions from its reply to the client. The server SHOULD pull and use additional information on the new peering from public sources to ensure routing security, e.g., AS-SETs to configure appropriate filters.

MONITORING Both client and server wait for sessions to establish. At any point, client may send a "GET STATUS" request to the server, to request the status of the session (by session ID). The client will send a structure along with the request, as follows:

• structure (where local refers to the server and peer refers to the client):
  • Session ID
  • Local ASN
  • Local IP
  • Peer ASN
  • Peer IP
  • Local BGP Role ()
  • Peer BGP Role ()
  • Local insert ASN (optional, as defined above)
  • Peer insert ASN (optional, as defined above)
  • Local monitoring session (optional, as defined above)
  • Peer monitoring session (optional, as defined above)
  • Peer Type
  • Session secret (optional, as defined above)
  • Location
  • Status

The server then responds with the same structure, with the information that it understands (status, etc).

COMPLETION If both sides report that the session is established, then peering is complete. If one side does not configure sessions within the server's acceptable configuration window (TimeWindow), then the server is entitled to remove the configured sessions and report "Unestablished" to the client.

Authentication Authentication to this API is performed with Bearer tokens. Two methods are defined below to obtain a bearer token, the choice of which is supported is up to operator preference however the authors recommend the use of RPKI Attested OAuth over reliance on an external OIDC provider.

OAuth with RPKI Attested OAuth It is envisioned the primary authentication mechanism for this API will be with RPKI Attested OAuth as defined in . When a client wishes to authenticate to a Peering API server using RPKI Attested OAuth, it first makes a POST request to the server's /oauth/client_register endpoint, containing the following JSON body: The idp_base URL provided MUST host an OAuth Discovery document as per . The Peering API server registers with the well-known scope urn:ietf:params:oauth:scope:peering-api. After successfully registering, the Peering API server stores its OAuth Client ID and Client Secret, along with the ASNs that this IdP is authoritative for. Future Bearer tokens can be checked against this list for which ASNs they are allowed to submit requests on behalf of. The Peering API server then returns the following JSON body to the client: A client may then request that its IdP perform an OAuth Token Exchange towards this Client ID, and use the resulting Bearer token to authenticate to the Peering API server.

OAuth with Peering DB As an alternative, this document allows, but does not recommend, the use of PeeringDB OAuth. First, the initiating OAuth2 Client is also the Resource Owner (RO) so it can follow the OAuth2 client credentials grant . In this example, the client will use PeeringDB OIDC credentials to acquire a JWT access token that is scoped for use with the receiving API. On successful authentication, PeeringDB provides the Resource Server (RS) with the client's email (for potential manual discussion), along with the client's usage entitlements (known as OAuth2 scopes), to confirm the client is permitted to make API requests on behalf of the initiating AS. | | | | | | Provide auth code | |<---------------------------------------------------------| | | | | Send auth code to Peer | | |-------------------------->| | | | | | | Exchange auth code for token | | |----------------------------->| | | | | | Return token | | |<-----------------------------| | | | | Peer determines | | permissions based on token | | | Send OK back to Initiator | |<--------------------------| ]]>

API Endpoints and Specifications Each peer needs a public API endpoint that will implement the API protocol. This API should be publicly listed in peeringDB and also as a potential expansion of which could provide endpoint integration to WHOIS (). Each API endpoint should be fuzz-tested and protected against abuse. Attackers should not be able to access internal systems using the API. Every single request should come in with a unique GUID called RequestID that maps to a peering request for later reference. This GUID format should be standardized across all requests. This GUID should be provided by the receiver once it receives the request and must be embedded in all communication. If there is no RequestID present then that should be interpreted as a new request and the process starts again. An email address is needed for communication if the API fails or is not implemented properly (can be obtained through PeeringDB). For a programmatic specification of the API, please see the public Github (). This initial draft fully specifies the Public Peering endpoints. Private Peering and Maintenance are under discussion, and the authors invite collaboration and discussion from interested parties.

DATA TYPES Please see specification () for OpenAPI format. Peering Location Contains string field listing the desired peering location in format pdb:ix:$IX_ID, and an enum specifying peering type (public or private). Session Status Status of BGP Session, both as connection status and approval status (Established, Pending, Approved, Rejected, Down, Unestablished, etc) Session Array Array of potential BGP sessions, with request UUID. Request UUID is optional for client, and required for server. Return URL is optional, and indicates the client's Peering API endpoint. The client's return URL is used by the server to request additional sessions. Client may provide initial UUID for client-side tracking, but the server UUID will be the final definitive ID. RequestID will not change across the request. BGP Session A structure that describes a BGP session and contains the following elements:

• local_asn (ASN of requestor)
• local_ip (IP of requestor, v4 or v6)
• peer_asn (server ASN)
• peer_ip (server-side IP)
• local_bgp_role (BGP role according to )
• peer_bgp_role (BGP role according to )
• local_insert_asn (optional, to support route servers, defaults to true)
• peer_insert_asn (optional, to support route servers, defaults to true)
• local_monitoring_session (optional, to support monitoring systems, defaults to false)
• peer_monitoring_session (optional, to support monitoring systems, defaults to false)
• peer_type (public or private)
• session_secret (optional, as defined above)
• location (Peering Location, as defined above)
• status (Session Status, as defined above)
• session_id (of individual session and generated by the server)

As not all elements are reflected in the OpenAPI definition to date, we define the missing fields here to be reflected in in the future.

• local_bgp_role and peer_bgp_role: these field describe the BGP roles of the local and peer side of the session according to represented by an integer. The roles for both sides MUST be set in a way that does not violate role correctness as defined in Section 4.2 of .
• local_insert_asn and peer_insert_asn: these fields define whether the local or peer side will insert their ASN into the AS path attribute of forwarded BGP routes. They are mostly relevant to route servers. The fields are boolean and optional. If not provided, they default to true.
• local_monitoring_session and peer_monitoring_session: these fields define whether the local or peer side of the session will forward routes to other ASes or not. As the role of monitoring systems is not defined in , we add this role via a boolean, optional flag. If not provided, they default to false. local_monitoring_session and peer_monitoring_sessions MUST NOT be true at the same time for the same session to avoid a role mismatch.

Error API Errors, for field validation errors in requests, and request-level errors. The above is sourced largely from the linked OpenAPI specification.

Discovery This document does not specify how to discover an ASN's Peering API endpoint. Some possible options are:

• Via the RPKI using
• Publication in WHOIS/RDAP
• Manual configuration

The preferred method is via the RPKI.

Endpoints (As defined in ). On each call, there should be rate limits, allowed senders, and other optional restrictions.

Public Peering over an Internet Exchange (IX)

• /sessions: ADD/RETRIEVE sessions visible to the calling PEER
  • Batch create new session resources
    • Establish new BGP sessions between peers, at the desired exchange.
    • Below is based on OpenAPI specification: .
    • POST /sessions
      • Request body: Session Array
      • Responses:
        • 200 OK:
          • Contents: Session Array (all sessions in request accepted for configuration). Should not all the sessions be accepted, the response also contains a list of sessions and the respective errors.
        • 400:
          • Error
        • 403:
          • Unauthorized to perform the operation
        • 422:
          • Please contact us, human intervention required
  • List all session resources. The response is paginated.
    • Given a request ID, query for the status of that request.
    • Given an ASN without request ID, query for status of all connections between client and server.
    • Below is based on OpenAPI specification: .
    • GET /sessions
      • Request parameters:
        • asn (requesting client's asn)
        • request_id (optional, UUID of request)
        • max_results (integer to indicate an upper bound for a given response page)
        • next_token (opaque and optional string received on a previous response page and which allows the server to produce the next page of results. Its absence indicates to the server that the first page is expected)
      • Response:
        • 200: OK
          • Contents: Session Array of sessions in request_id, if provided. Else, all existing and in-progress sessions between client ASN and server.
            • next_token (opaque and optional string the server expects to be passed back on the request for the next page. Its absence indicates to the client that no more pages are available)
        • 400:
          • Error (example: request_id is invalid)
        • 403:
          • Unauthorized to perform the operation
• /sessions/{session_id}: Operate on individual sessions
  • Retrieve an existing session resource
    • Below is based on OpenAPI specification: .
    • GET /sessions/{session_id}
      • Request parameters:
        • session_id returned by the server on creation or through the session list operation.
      • Responses:
        • 200 OK:
          • Contents: Session structure with current attributes
        • 400:
          • Error (example: session_id is invalid)
        • 403:
          • Unauthorized to perform the operation
        • 404:
          • The session referred by the specified session_id does not exist or is not visible to the caller
  • Delete a session.
    • Given a session ID, delete it which effectively triggers an depeering from the initiator.
    • Below is based on OpenAPI specification: .
    • DELETE /sessions/{session_id}
      • Request parameters:
        • session_id returned by the server on creation or through the session list operation.
      • Response:
        • 204: OK
          • Contents: empty response as the session is processed and hard deleted
        • 400:
          • Error (example: session_id is invalid)
        • 403:
          • Unauthorized to perform the operation
        • 404:
          • The session referred by the specified session_id does not exist or is not visible to the caller
        • 422:
          • Please contact us, human intervention required

UTILITY API CALLS Endpoints which provide useful information for potential interconnections.

• /locations: LIST POTENTIAL PEERING LOCATIONS
  • List potential peering locations, both public and private. The response is paginated.
    • Below is based on OpenAPI specification: .
    • GET /locations
      • Request parameters:
        • asn (Server ASN, with which to list potential connections)
        • location_type (Optional: Peering Location)
        • max_results (integer to indicate an upper bound for a given response page)
        • next_token (opaque and optional string received on a previous response page and which allows the server to produce the next page of results. Its absence indicates to the server that the first page is expected)
      • Response:
        • 200: OK
          • Contents: List of Peering Locations.
            • next_token (opaque and optional string the server expects to be passed back on the request for the next page. Its absence indicates to the client that no more pages are available)
        • 400:
          • Error
        • 403:
          • Unauthorized to perform the operation

Private Peering (DRAFT)

• ADD/AUGMENT PNI
• Parameters:
  • Peer ASN
  • Facility
  • email address (contact)
  • Action type: add/augment
  • LAG struct:
    • IPv4
    • IPv6
    • Circuit ID
  • Who provides LOA? (and where to provide it).
• Response:
  • 200:
    • LAG struct, with server data populated
    • LOA or way to receive it
    • Request ID
  • 40x: rejections
• REMOVE PNI
  • As ADD/AUGMENT in parameters. Responses will include a requestID and status.

Public Peering Session Negotiation As part of public peering configuration, this draft must consider how the client and server should handshake at which sessions to configure peering. At first, a client will request sessions A, B, and C. The server may choose to accept all sessions A, B, and C. At this point, configuration proceeds as normal. However, the server may choose to reject session B. At that point, the server will reply back with A and C marked as "Accepted," and B as "Rejected." The server will then configure A and C, and wait for the client to configure A and C. If the client configured B as well, it will not come up. This draft encourages peers to set up garbage collection for unconfigured or down peering sessions, to remove stale configuration and maintain good router hygiene. Related to rejection, if the server would like to configure additional sessions with the client, the server may either reject all the session that do not meet the criteria caused by such absence in the client's request or approve the client's request and issue a separate request to the client's server requesting those additional peering sessions D and E. The server will configure D and E on their side, and D and E will become part of the sessions requested in the UUID. The client may choose whether or not to accept those additional sessions. If they do, the client should configure D and E as well. If they do not, the client will not configure D and E, and the server should garbage-collect those pending sessions. As part of the IETF discussion, the authors would like to discuss how to coordinate which side unfilters first. Perhaps this information could be conveyed over a preferences vector.

Private Peering Through future discussion with the IETF, the specification for private peering will be solidified. Of interest for discussion includes Letter of Authorization (LOA) negotiation, and how to coordinate unfiltering and configuration checks.

Maintenance This draft does not want to invent a new ticketing system. However, there is an opportunity in this API to provide maintenance notifications to peering partners. If there is interest, this draft would extend to propose a maintenance endpoint, where the server could broadcast upcoming and current maintenance windows. A maintenance message would follow a format like:

• Title: string
• Start Date: date maintenance start(s/ed): UTC
• End Date: date maintenance ends: UTC
• Area: string or enum
• Details: freeform string

The "Area" field could be a freeform string, or could be a parseable ENUM, like (BGP, PublicPeering, PrivatePeering, Configuration, Caching, DNS, etc). Past maintenances will not be advertised.

Security Considerations This document describes a mechanism to standardize the discovery, creation and maintenance of peering relationships across autonomous systems (AS) using an out-of-band application programming interface (API). With it, AS operators take a step to operationalize their peering policy with new and existing peers in ways that improve or completely replace manual business validations, ultimately leading to the automation of the interconnection. However, this improvement can only be fully materialized when operators are certain that such API follows the operational trust and threat models they are comfortable with, some of which are documented in BGP operations and security best practices (). To that extent, this document assumes the peering API will be deployed following a strategy of defense in-depth and proposes the following common baseline threat model below.

Threats Each of the following threats assume a scenario where an arbitrary actor is capable of reaching the peering API instance of a given operator, the client and the operator follow their own endpoint security and maintenance practices, and the trust anchors in use are already established following guidelines outside of the scope of this document.

• T1: A malicious actor with physical access to the IX fabric and peering API of the receiver can use ASN or IP address information to impersonate a different IX member to discover, create, update or delete peering information which leads to loss of authenticity, confidentiality, and authorization of the spoofed IX member.
• T2: A malicious actor with physical access to the IX fabric can expose a peering API for an IX member different of its own to accept requests on behalf of such third party and supplant it, leading to a loss of authenticity, integrity, non-repudiability, and confidentiality between IX members.
• T3: A malicious actor without physical access to the IX fabric but with access the the peering API can use any ASN to impersonate any autonomous system and overload the receiver's peering API internal validations leading to a denial of service.

Mitigations The following list of mitigations address different parts of the threats identified above:

• M1: Authorization controls - A initiator using a client application is authorized using the claims presented in the request prior to any interaction with the peering API (addresses T1, T2).
• M2: Proof of holdership - The initiator of a request through a client can prove their holdership of an Internet Number Resource (addresses T1, T3).
• M3: Request integrity and proof of possession - The peering API can verify HTTP requests signed with a key that is cryptographically bound to the authorized initiator (addresses T1, T2).

The Peering API does not enforce any kind of peering policy on the incoming requests. It is left to the peering API instance implementation to enforce the AS-specific peering policy. This document encourages each peer to consider the needs of their peering policy and implement request validation as desired.

Authorization controls The peering API instance receives HTTP requests from a client application from a peering initiator. Those requests can be authorized using the authorization model based on OAuth 2.0 () with the OpenID Connect core attribute set. The choice of OpenID Connect is to use a standardized and widely adopted authorization exchange format based on JSON Web Tokens () which allows interoperation with existing web-based application flows. JWT tokens also supply sufficient claims to implement receiver-side authorization decisions by third parties when used as bearer access tokens (). The peering API instance (a resource server in OAuth2 terms) should follow the bearer token usage () which describes the format and validation of an access token obtained from the Oauth 2.0 Authorization Server. The resource server should follow the best practices for JWT access validation () and in particular verify that the access token is constrained to the resource server via the audience claim. Upon successful access token validation, the resource server should decide whether to proceed with the request based on the presence of expected and matching claims in the access token or reject it altogether. The core identity and authorization claims present in the access token may be augmented with specific claims vended by the Authorization Service. This document proposes to use PeeringDB's access token claims as a baseline to use for authorization, however the specific matching of those claims to an authorization business decision is specific to each operator and outside of this specification. Resource servers may also use the claims in the access token to present the callers' identity to the application and for auditing purposes.

Proof of holdership The peering API defined in this document uses ASNs as primary identifiers to identify each party on a peering session besides other resources such as IP addresses. ASNs are explicitly expected in some API payloads but are also implicitly expected when making authorization business decisions such as listing resources that belong to an operator. Given that ASNs are Internet Number Resources assigned by RIRs and that the OAuth2 Authorization Server in use may not be operated by any of those RIRs, as it is the case of PeeringDB or any other commercial OAuth2 service, JWT claims that contain an ASN need be proved to be legitimately used by the initiator. This document proposes to attest ASN resource holdership using a mechanism based on RPKI () and in particular with the use of RPKI Attested OAuth ().

Request integrity and proof of possession The API described in this document follows REST () principles over an HTTP channel to model the transfer of requests and responses between peers. Implementations of this API should use the best common practices for the API transport () such as TLS. However, even in the presence of a TLS channel with OAuth2 bearer tokens alone, neither the client application nor the API can guarantee the end-to-end integrity of the message request or the authenticity of its content. One mechanism to add cryptographic integrity and authenticity validation can be the use a mutual authentication scheme to negotiate the parameters of the TLS channel. This requires the use of a web PKI () to carry claims for use in authorization controls, to bind such PKI to ASNs for proof of holdership, and the use of client certificates on the application. Instead, this document proposes to address the message integrity property by cryptographically signing the parameters of the request with a key pair that creates a HTTP message signature to be included in the request (). The client application controls the lifecycle of this key pair. The authenticity property of the messages signed with such key pair is addressed by binding the public key of the pair to the JWT access token in one of its claims of the access token using a mechanism that demonstrates proof of possession of the private key . With these two mechanisms, the resource server should authenticate, authorize, and validate the integrity of the request using a JWT access token that can rightfully claim to represent a given ASN.

IANA Considerations

OAuth URI This document adds one new entry to the "OAuth URI" registry:

URN	Common Name	Reference
urn:ietf:params:oauth:scope:peering-api	Well-known scope for the BGP Peering API	This document

References Normative References n.d. n.d. n.d. n.d. In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. This specification describes how to use bearer tokens in HTTP requests to access OAuth 2.0 protected resources. Any party in possession of a bearer token (a "bearer") can use it to get access to the associated resources (without demonstrating possession of a cryptographic key). To prevent misuse, bearer tokens need to be protected from disclosure in storage and in transport. [STANDARDS-TRACK] This specification defines a protocol for an HTTP- and JSON-based Security Token Service (STS) by defining how to request and obtain security tokens from OAuth 2.0 authorization servers, including security tokens employing impersonation and delegation. The OAuth 2.0 authorization framework enables a third-party application to obtain limited access to an HTTP service, either on behalf of a resource owner by orchestrating an approval interaction between the resource owner and the HTTP service, or by allowing the third-party application to obtain access on its own behalf. This specification replaces and obsoletes the OAuth 1.0 protocol described in RFC 5849. [STANDARDS-TRACK] JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. The claims in a JWT are encoded as a JSON object that is used as the payload of a JSON Web Signature (JWS) structure or as the plaintext of a JSON Web Encryption (JWE) structure, enabling the claims to be digitally signed or integrity protected with a Message Authentication Code (MAC) and/or encrypted. This specification defines a profile for issuing OAuth 2.0 access tokens in JSON Web Token (JWT) format. Authorization servers and resource servers from different vendors can leverage this profile to issue and consume access tokens in an interoperable manner. JSON Web Tokens, also known as JWTs, are URL-safe JSON-based security tokens that contain a set of claims that can be signed and/or encrypted. JWTs are being widely used and deployed as a simple security token format in numerous protocols and applications, both in the area of digital identity and in other application areas. This Best Current Practices document updates RFC 7519 to provide actionable guidance leading to secure implementation and deployment of JWTs. This document describes a mechanism for creating, encoding, and verifying digital signatures or message authentication codes over components of an HTTP message. This mechanism supports use cases where the full HTTP message may not be known to the signer and where the message may be transformed (e.g., by intermediaries) before reaching the verifier. This document also describes a means for requesting that a signature be applied to a subsequent HTTP message in an ongoing HTTP exchange. This document describes a mechanism for sender-constraining OAuth 2.0 tokens via a proof-of-possession mechanism on the application level. This mechanism allows for the detection of replay attacks with access and refresh tokens. Informative References n.d. This document discusses the Border Gateway Protocol (BGP), which is an inter-Autonomous System routing protocol. The primary function of a BGP speaking system is to exchange network reachability information with other BGP systems. This network reachability information includes information on the list of Autonomous Systems (ASes) that reachability information traverses. This information is sufficient for constructing a graph of AS connectivity for this reachability from which routing loops may be pruned, and, at the AS level, some policy decisions may be enforced. BGP-4 provides a set of mechanisms for supporting Classless Inter-Domain Routing (CIDR). These mechanisms include support for advertising a set of destinations as an IP prefix, and eliminating the concept of network "class" within BGP. BGP-4 also introduces mechanisms that allow aggregation of routes, including aggregation of AS paths. This document obsoletes RFC 1771. [STANDARDS-TRACK] Applications often use HTTP as a substrate to create HTTP-based APIs. This document specifies best practices for writing specifications that use HTTP to define new application protocols. It is written primarily to guide IETF efforts to define application protocols using HTTP for deployment on the Internet but might be applicable in other situations. This document obsoletes RFC 3205. Route leaks are the propagation of BGP prefixes that violate assumptions of BGP topology relationships, e.g., announcing a route learned from one transit provider to another transit provider or a lateral (i.e., non-transit) peer or announcing a route learned from one lateral peer to another lateral peer or a transit provider. These are usually the result of misconfigured or absent BGP route filtering or lack of coordination between autonomous systems (ASes). Existing approaches to leak prevention rely on marking routes by operator configuration, with no check that the configuration corresponds to that of the External BGP (eBGP) neighbor, or enforcement of the two eBGP speakers agreeing on the peering relationship. This document enhances the BGP OPEN message to establish an agreement of the peering relationship on each eBGP session between autonomous systems in order to enforce appropriate configuration on both sides. Propagated routes are then marked according to the agreed relationship, allowing both prevention and detection of route leaks. This document specifies how to augment the Routing Policy Specification Language inetnum: class to refer specifically to geofeed data comma-separated values (CSV) files and describes an optional scheme that uses the Routing Public Key Infrastructure to authenticate the geofeed data CSV files. This document updates the specification of the WHOIS protocol, thereby obsoleting RFC 954. The update is intended to remove the material from RFC 954 that does not have to do with the on-the-wire protocol, and is no longer applicable in today's Internet. This document does not attempt to change or update the protocol per se, or document other uses of the protocol that have come into existence since the publication of RFC 954. [STANDARDS-TRACK] The Border Gateway Protocol (BGP) is the protocol almost exclusively used in the Internet to exchange routing information between network domains. Due to this central nature, it is important to understand the security measures that can and should be deployed to prevent accidental or intentional routing disturbances. This document describes measures to protect the BGP sessions itself such as Time to Live (TTL), the TCP Authentication Option (TCP-AO), and control-plane filtering. It also describes measures to better control the flow of routing information, using prefix filtering and automation of prefix filters, max-prefix filtering, Autonomous System (AS) path filtering, route flap dampening, and BGP community scrubbing. This document describes an architecture for an infrastructure to support improved security of Internet routing. The foundation of this architecture is a Resource Public Key Infrastructure (RPKI) that represents the allocation hierarchy of IP address space and Autonomous System (AS) numbers; and a distributed repository system for storing and disseminating the data objects that comprise the RPKI, as well as other signed objects necessary for improved routing security. As an initial application of this architecture, the document describes how a legitimate holder of IP address space can explicitly and verifiably authorize one or more ASes to originate routes to that address space. Such verifiable authorizations could be used, for example, to more securely construct BGP route filters. This document is not an Internet Standards Track specification; it is published for informational purposes. Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) are used to protect data exchanged over a wide range of application protocols and can also form the basis for secure transport protocols. Over the years, the industry has witnessed several serious attacks on TLS and DTLS, including attacks on the most commonly used cipher suites and their modes of operation. This document provides the latest recommendations for ensuring the security of deployed services that use TLS and DTLS. These recommendations are applicable to the majority of use cases. RFC 7525, an earlier version of the TLS recommendations, was published when the industry was transitioning to TLS 1.2. Years later, this transition is largely complete, and TLS 1.3 is widely available. This document updates the guidance given the new environment and obsoletes RFC 7525. In addition, this document updates RFCs 5288 and 6066 in view of recent attacks. This memo profiles the X.509 v3 certificate and X.509 v2 certificate revocation list (CRL) for use in the Internet. An overview of this approach and model is provided as an introduction. The X.509 v3 certificate format is described in detail, with additional information regarding the format and semantics of Internet name forms. Standard certificate extensions are described and two Internet-specific extensions are defined. A set of required certificate extensions is specified. The X.509 v2 CRL format is described in detail along with standard and Internet-specific extensions. An algorithm for X.509 certification path validation is described. An ASN.1 module and examples are provided in the appendices. [STANDARDS-TRACK]

Acknowledgments The authors would like to thank their collaborators, who implemented API versions and provided valuable feedback on the design.

• Ben Blaustein
• Jakub Heichman (Meta)
• Prithvi Nath Manikonda (Amazon)
• Q Misell (Glauca Digital)
• Stefan Pratter (20C)
• Aaron Rose (Amazon)
• Ben Ryall (Meta)
• Erica Salvaneschi (Cloudflare)
• Job Snijders
• David Tuber (Cloudflare)
• Matthias Wichtlhuber (DE-CIX)