Independent Submission S. Halén
Request for Comments: 9932 The Swedish Internet Foundation
Category: Informational J. Schlyter
ISSN: 2070-1721 Kirei AB
February
March 2026
Mutually Authenticating TLS in the Context of Federations
Abstract
This Informational Independent Submission to the RFC Series describes
a means to use TLS 1.3 to perform machine-to-machine mutual
authentication within federations. This memo is not a standard. It
does not modify the TLS protocol in any way, nor does it require
changes to common TLS libraries. TLS is specified and standardized
by the IETF's TLS Working Group.
The framework enables interoperable trust management for federated
machine-to-machine communication. It introduces a centrally managed
trust anchor and a controlled metadata publication process, ensuring
that only authorized members are identifiable within the federation.
These mechanisms support unambiguous entity identification and reduce
the risk of impersonation, promoting secure and policy-aligned
interaction across organizational boundaries.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This is a contribution to the RFC Series, independently of any other
RFC stream. The RFC Editor has chosen to publish this document at
its discretion and makes no statement about its value for
implementation or deployment. Documents approved for publication by
the RFC Editor are not candidates for any level of Internet Standard;
see Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9932.
Copyright Notice
Copyright (c) 2026 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document.
Table of Contents
1. Introduction
1.1. Reserved Words
1.2. Terminology
2. Diverse Design Patterns
3. Trust Model
3.1. Role of the Federation Operator
3.2. Federation Members' Responsibilities
3.3. Chain of Trust
3.4. Member Vetting
3.5. Metadata Authenticity
4. Metadata Repository
4.1. Metadata Submission
4.2. Maintaining Up-to-Date Metadata
5. Authentication
5.1. Public Key Pinning
5.1.1. Benefits of Public Key Pinning
5.2. Pin Discovery and Preloading
5.3. Verification of Received Certificates
5.4. Failure to Validate
5.5. Certificate Rotation
5.6. Implementation Guidelines
6. Federation Metadata
6.1. Federation Metadata Claims
6.1.1. Entities
6.2. Metadata Schema
6.3. Example Metadata
6.4. Metadata Signing
6.5. Example Signature Protected Header
7. Example Usage Scenarios
7.1. Client Behavior
7.2. Server Behavior
7.3. SPKI Generation
7.4. Curl and Public Key Pinning
8. Deployments of the MATF Framework
8.1. Skolfederation Moa
8.2. Swedish National Agency for Education
8.3. Sambruk's EGIL
9. Security Considerations
9.1. Security Risks and Trust Management
9.2. TLS
9.3. Federation Metadata Updates
9.4. Verifying the Federation Metadata Signature
9.5. Time Synchronization
10. IANA Considerations
11. References
11.1. Normative References
11.2. Informative References
Appendix A. JSON Schema for MATF Metadata
Acknowledgements
Authors' Addresses
1. Introduction
This document describes the Mutually Authenticating TLS in
Federations (MATF) framework, developed to complement multilateral
Security Assertion Markup Language (SAML) federations within the
education sector. These federations often rely on just-in-time
provisioning, where user accounts are created at first login based on
information from the SAML assertion. However, educators need to be
able to manage resources and classes before students access the
service. MATF bridges this gap by using secure machine-to-machine
communication, enabling pre-provisioning of user information with a
trust model and metadata structure inspired by SAML federations.
MATF is designed specifically for secure authentication in machine-
to-machine contexts, such as RESTful APIs (where "RESTful" refers to
the Representational State Transfer (REST) architecture) and service-
to-service interactions, and is not intended for browser-based
authentication. Because its applicability in a browser environment
has not been studied, using MATF within browsers is not recommended.
Doing so may introduce risks that differ from those typically
addressed by standard browser security models.
This work is not a product of the IETF, does not represent a
standard, and has not achieved community consensus. It aims to
address specific federation challenges and provide a framework for
secure communication.
TLS is specified by the IETF TLS Working Group. TLS 1.3 is defined
in [RFC8446]. Additional information about the TLS Working Group is
available at <https://datatracker.ietf.org/wg/tls/about/>.
1.1. Reserved Words
This document is an Informational RFC, which means it offers
information and guidance but does not specify mandatory standards.
Therefore, the keywords used throughout this document are for
informational purposes only and do not imply any specific
requirements.
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 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
1.2. Terminology
Federation: A trusted network of entities that adhere to common
security policies and standards, using MATF for secure
communication.
Federation Member: An entity that has been approved to join the
federation and can leverage MATF for secure communication with
other members.
Federation Operator: The entity responsible for the overall
operation and management of the federation, including managing the
federation metadata, enforcing security policies, and onboarding
new members.
Federation Metadata: A cryptographically signed document containing
information about all entities within the federation.
Metadata Repository: A centralized repository storing information
about all entities within the federation.
Member Metadata: Information about entities associated with a
specific member within the federation.
Member Vetting: The process of verifying and approving applicants to
join the federation, ensuring they meet security and
trustworthiness requirements.
Trust Anchor: The federation's root of trust is established by the
public key used to verify federation metadata signatures, which
allows participants to confidently rely on the information it
contains.
2. Diverse Design Patterns
MATF is designed to be flexible and adaptable to the varying needs of
different federations. Federations can differ significantly in terms
of size, scope, and security requirements, which makes it challenging
to prescribe a one-size-fits-all trust framework and security
measures.
For instance, in the European Union, Regulation (EU) No 910/2014 (the
electronic identification, authentication, and trust services (eIDAS)
Regulation [eIDAS])
Regulation) [eIDAS] establishes a regulatory framework for electronic
identification and trust services for electronic transactions in the
internal market. The eIDAS Regulation provides a basis for cross-
border recognition of notified electronic identification schemes and
for regulated trust services.
Similarly, national federations, such as those found in education or
healthcare sectors, often have their own specific trust frameworks
and security measures tailored to their unique needs. These
federations may leverage existing national identification systems or
other trusted credentials to establish member identities and ensure
secure interactions.
Organizations may also set up their own federations, tailored to the
specific security requirements and trust models relevant to their
context. For example, a private business federation might establish
its own vetting processes and trust framework based on the nature of
its business and the sensitivity of the data being exchanged.
By allowing federations the flexibility to tailor their trust
frameworks and security measures, MATF can support a wide range of
use cases. This flexibility is crucial for accommodating the diverse
requirements and challenges faced by different federations, ensuring
a secure and adaptable system for establishing trust and facilitating
secure communication.
3. Trust Model
The MATF framework operates on a trust model that is central to its
design and functionality. This section outlines the key components
of this trust model and its implications for federation members and
the federation operator.
3.1. Role of the Federation Operator
The federation operator plays a critical role in the MATF framework.
This entity is responsible for:
* Managing the central trust anchor, which is used to establish
trust across different domains within the federation federation.
* Vetting federation members to ensure they meet the required
standards and policies.
* Maintaining and securing the federation metadata, which includes
public key pins [RFC7469], issuer certificates, and other
essential information.
Additionally, the federation operator SHOULD develop their own threat
models to proactively identify potential risks and threats. This
process involves examining the operating environment, evaluating both
internal and external threats, and understanding how vulnerabilities
can be exploited. The goal of the threat model is to enable the
federation operator to establish mitigation strategies that address
the identified risks.
The security and stability of the federation rely on the integrity
and competence of the federation operator. Members must be able to
fully trust this central authority, as its role is essential to
maintaining the federation's reliability and security.
3.2. Federation Members' Responsibilities
Federation members share the responsibility of maintaining trust and
security within the federation.
Their responsibilities include:
* Adhering to the federation's security policies and procedures.
* Ensuring the accuracy and timeliness of their metadata
submissions.
* Cooperating with the federation operator's vetting and security
measures.
By fulfilling these responsibilities, federation members help sustain
the trust framework that enables secure and reliable communication
within the federation.
Federation members submit member metadata to the federation. As part
of federation operations, the federation MUST ensure the authenticity
and integrity of submitted member metadata and the authenticity of
the submitting member.
3.3. Chain of Trust
Each federation operates within a trust framework that encompasses
its own security policies and procedures. This framework is designed
to ensure the integrity, authenticity, and confidentiality of
communications within the federation. Key components of this
framework include:
* Public key pinning [RFC7469] and preloading to thwart on-path
attacks by rejecting peers whose public key in the presented
certificate does not match a pin published in the federation
metadata.
* Regular updates and verification of federation metadata to prevent
the use of outdated or compromised information.
The federation operator aggregates, signs, and publishes the
federation metadata, which combines all members' member metadata
along with additional federation-specific information. By placing
trust in the federation and its associated federation metadata
signature verification key, federation members trust the information
contained within the federation metadata.
The trust anchor for the federation is established through the
federation metadata signature verification key, a critical component
requiring secure distribution and verification. To achieve this, the
signature verification key material is distributed using a JSON Web
Key (JWK) Set [RFC7517], providing a flexible framework for exposing
multiple public keys, including the current signature verification
key and keys for rollover. This structured approach ensures members
can readily access the necessary keys for verification purposes.
An additional layer of security is introduced through thumbprint
verification [RFC7638], where federation members can independently
verify the key's authenticity. This involves comparing the
calculated cryptographic thumbprint of the key with a trusted value,
ensuring its integrity. Importantly, this verification process can
be conducted through channels separate from the JWK Set itself,
enhancing security by eliminating reliance on a single distribution
mechanism.
This trust framework is essential for enabling seamless and secure
interoperability across different trust domains within the
federation.
3.4. Member Vetting
To ensure the security and integrity of the MATF framework, a member
vetting process is essential. Detailed vetting processes are beyond
the scope of this document but can be guided by established
frameworks such as eIDAS and eduGAIN.
The following are non-normative references to established frameworks:
* eIDAS: The eIDAS regulation can provide guidance for member
vetting and identity assurance practices.
* eduGAIN: eduGAIN is an interfederation service connecting identity
federations worldwide, primarily within the research and education
sector. eduGAIN documentation on participation requirements and
federation practices can inform member vetting processes
[eduGAIN].
3.5. Metadata Authenticity
Ensuring the authenticity of metadata is necessary for maintaining
the security and trustworthiness of the MATF framework. This
document specifies mechanisms for protecting and verifying the
authenticity of federation metadata, including JWS signing.
Operational procedures for authenticating member metadata submissions
are outside the scope of this document and are defined by the
federation operator or applicable regulatory bodies.
4. Metadata Repository
The MATF metadata repository acts as a central vault, securely
storing all information about all participating federation members
and their respective entities. This information, known as federation
metadata, is presented as a JSON Web Signature (JWS) [RFC7515] to
ensure its authenticity and integrity.
The metadata repository is subject to stringent security measures to
safeguard the integrity of the stored information. This MAY involve:
* Member management: The federation operator can centrally enforce
security policies and vet new members before they are added to the
repository.
* Access controls: Access to repository management functions and
member metadata submission endpoints SHOULD be restricted to
authorized federation members.
* Regular backups: Robust backup procedures ensure data recovery in
case of unforeseen circumstances.
Before member metadata is added to the federation's repository, the
submitted metadata MUST undergo a validation process. This process
verifies the accuracy, completeness, and validity of the information
provided by a member. Metadata that does not pass validation MUST be
rejected. The validation process MUST include, at a minimum, the
following checks:
* Format validation: The submitted metadata is checked to ensure
that it conforms to the schema and format specifications defined
in Section 6.2 and Appendix A.
* Unique entity identifier: The submitted metadata is checked to
ensure that the entity_id value, as defined in Section 6.1.1, is
not already registered by another member.
* Unique public key pin digests: The submitted metadata is checked
to ensure that pins entries, as defined in Section 6.1.1.1, do not
introduce a digest value that is already registered to a different
entity_id. While reuse of the same digest value within the same
entity_id is permitted, uniqueness across different entities is
REQUIRED to prevent identity collisions and to support the
resolution of a unique entity_id from a derived pin, as specified
in Section 5.2.
* Issuer certificate checks: The issuer certificates in issuers, as
defined in Section 6.1.1, are checked to ensure that they are
syntactically valid, not expired, and use algorithms that meet the
federation's security requirements.
* Tag validation: Tags, as defined in Section 6.1.1.1, are checked
to ensure that they conform to the defined tag syntax. If the
federation defines an approved set of tag values, submitted tags
are checked to ensure that they are members of that set.
The metadata repository provides a controlled location for storing
member metadata and for producing federation metadata for
distribution to federation members.
4.1. Metadata Submission
It is up to the federation, through its governance and operational
processes, to determine which channels are provided to members for
submitting their metadata to the metadata repository. Members
typically have the option to upload the metadata directly to the
repository, provided such functionality exists, or to send it to the
federation operator through a designated secure channel. If an
insecure channel is used, additional measures MUST be taken to verify
the authenticity and integrity of the metadata. Such measures may
include verifying the checksum of the metadata through another
channel. The choice of submission channel may depend on factors such
as the federation's guidelines and the preferences of the member.
4.2. Maintaining Up-to-Date Metadata
In a MATF federation, accurate and current metadata is essential for
ensuring secure and reliable communication between members. This
necessitates maintaining up-to-date metadata accessible by all
members.
* Federation metadata: The federation operator publishes a JWS
containing an aggregate of all entity metadata. This JWS serves
as the source of truth for information about all members within
the federation. Outdated information in the JWS can lead to
issues such as failed connections, discovery challenges, and
potential security risks.
* Local metadata: Each member maintains a local metadata store
containing information about other members within the federation.
This information is retrieved from the federation's publicly
accessible JWS. Outdated data in the local store can hinder a
member's ability to discover and connect with other relevant
entities.
The following outlines the procedures for keeping metadata up to
date:
* Federation Operator Role: The federation operator plays a crucial
role in maintaining data integrity within the federation. Their
responsibilities include:
- Defining rules for metadata management that MUST include, at a
minimum, expiration and cache time management.
- Implementing mechanisms to update the published federation
metadata, ensuring it adheres to the expiration time (exp as
defined in Section 6.1) and cache TTL (cache_ttl as defined in
Section 6.1) specifications.
* Member Responsibility: Members must follow the federation's
metadata management rules and refresh their local metadata store
according to the defined expiration and cache regulations.
By adhering to these responsibilities, the federation ensures that
information remains valid for the defined timeframe and that caching
mechanisms utilize up-to-date data effectively.
5. Authentication
All communication established within the federation uses TLS 1.3
[RFC8446] with mutual authentication. This mechanism ensures the
authenticity of both communicating parties, establishing a robust
foundation for secure data exchange.
5.1. Public Key Pinning
MATF implements public key pinning based on [RFC7469]. Public key
pinning associates one or more unique public keys with each
federation endpoint, which are stored in the federation metadata.
During a connection, clients and servers extract the public key from
the presented certificate and verify that it matches the
preconfigured public key pins retrieved from the federation metadata.
5.1.1. Benefits of Public Key Pinning
The decision to utilize public key pinning in the MATF framework was
driven by several critical factors aimed at enhancing security and
ensuring trust.
5.1.1.1. Interfederation Trust
In interfederation environments, where multiple federations need to
trust each other, public key pinning remains effective. Members can
validate entities in other federations using pins published through
shared metadata, ensuring trust across boundaries. Unlike private
certificate chains, which can become complex and difficult to manage
across multiple federations, public key pinning provides a
straightforward mechanism for establishing trust. MATF
interfederation addresses this challenge by aggregating metadata from
all participating federations into a unified metadata repository.
This shared metadata enables secure communication between entities in
different federations, ensuring consistent key validation and robust
cross-federation trust and security.
5.1.1.2. Fortifying Security Against Threats
Public key pinning provides a robust defense mechanism by directly
binding a peer to a specific public key. This ensures that only the
designated key is trusted, preventing attackers from exploiting
fraudulent certificates. By eliminating reliance on external trust
intermediaries, this approach significantly enhances resilience
against potential threats.
5.1.1.3. Use of Self-Signed Certificates
The use of self-signed certificates within the federation leverages
public key pinning to establish trust. By bypassing external
Certificate Authorities (CAs), servers and clients rely on the
federation's mechanisms to validate trust. Public key pinning
ensures that only the specific self-signed public keys, identified by
key pins in the metadata, are trusted.
5.1.1.4. Revocation
In deployments that rely on certificate chains and certificate
revocation mechanisms, revocation can be complex and slow. This
complexity arises because a certificate that can no longer be
trusted, and potentially other certificates within the chain, may
need to be revoked and reissued. Public key pinning mitigates this
complexity by allowing clients to base trust decisions on pinned
public keys rather than on certificate chains.
If a public key can no longer be trusted within a MATF federation,
the associated pin is removed. Updated metadata is published. The
updated metadata includes a new pin corresponding to the public key
in the replacement certificate. This approach reduces reliance on
certificate revocation mechanisms and shifts the trust relationship
to the specific, updated public key identified by its pin.
5.2. Pin Discovery and Preloading
Peers in the federation obtain public key pins from the federation
metadata. These pins serve as preconfigured trust parameters used
for validation, as specified in Section 5.3.
The federation MUST define discovery rules. These rules describe how
peers use federation metadata claims such as organization and tags to
identify relevant endpoints and their pins.
Before initiating or accepting a connection, a peer MUST preload the
pins for the selected or authorized endpoints from its local metadata
store. Maintenance of the local metadata store, including refresh
behavior and expiry handling, is specified in Section 4.2.
To support peer identification, the preloaded state MUST enable
mapping from a derived pin to the corresponding entity_id. This may
be achieved by maintaining a local index that maps each preloaded pin
value to its associated entity_id.
A server MAY preload only the pins for clients that satisfy the
server's connection policy (for example, based on organization or
tags). Pin validation enforces the resulting policy as specified in
Section 5.3.
5.3. Verification of Received Certificates
Upon connection establishment, both endpoints MUST verify that the
public key in the presented peer certificate matches a pin published
in the federation metadata. This validation MAY be performed by the
TLS stack or by application logic.
In architectures where an intermediary terminates the TLS session,
pin validation MUST be performed by either the intermediary or the
application. If the application performs pin validation, the
intermediary MUST forward the peer certificate or a derived pin to
the application. The application MUST be able to determine the peer
entity_id from the forwarded information and the federation metadata.
This resolution relies on the client pin digest uniqueness property
specified in Section 6.1.1.1.
If the intermediary performs pin validation, it MUST propagate the
peer certificate, the derived pin, or the entity_id to the
application to enable authorization.
The channel between the intermediary and the application MUST be
integrity protected and MUST provide endpoint authentication.
Any conveyed certificate, pin, or identity used for this purpose MUST
be derived directly from the TLS session. Implementations MUST NOT
accept these values from peer-supplied application data.
If the implementation permits disabling default CA-based certificate
chain validation, it SHOULD do so while still enforcing pin
validation. If chain validation is required, the trust anchors used
for certificate chain validation MUST be selected from the issuers
listed in the federation metadata.
If no matching pin is found for a peer, the connection MUST be
handled according to Section 5.4.
5.4. Failure to Validate
A received certificate that fails validation MUST result in the
immediate termination of the connection. This includes scenarios
where the derived pin does not match any preloaded pin or where the
peer identity cannot be resolved. This strict enforcement ensures
that only authorized and secure communication channels are
established within the federation.
5.5. Certificate Rotation
To replace a certificate, whether due to expiration or other reasons,
the following procedure MUST be followed:
1. Submitting updated metadata. When a certificate is scheduled for
rotation, the federation member submits updated metadata that
adds the pin for the new public key alongside the already
published pins. The federation operator republishes the signed
federation metadata aggregate, making the new pin available to
all federation members.
2. Propagation period. Federation members MUST refresh their local
metadata stores as specified in Section 4.2. The rotating member
MUST allow sufficient time for peers to refresh and preload the
new pin before switching to the new certificate.
3. Switching to the new certificate. After the propagation period
has elapsed, the rotating member updates its TLS stack to present
the new certificate. This allows peers that have preloaded the
new pin to validate the rotated certificate.
4. Removing the old pin. Following a successful transition, the
rotating member MUST submit updated metadata excluding the old
pin. The federation operator republishes the aggregate, ensuring
that only current public keys remain trusted within the
federation.
5.6. Implementation Guidelines
The placement of pin validation depends on the deployment
architecture. For clients, validation is typically performed by the
component initiating the TLS connection. For servers using an
intermediary, the communication channel between the intermediary and
the application MUST be integrity protected to prevent tampering with
forwarded peer identity material.
When an intermediary propagates peer identity material (for example,
the peer certificate, a derived pin, or the entity_id) using HTTP
header fields, those header fields are the mechanism used to fulfill
the requirements specified in Section 5.3. For each header field
name used for this purpose, the intermediary MUST remove any instance
of that header field received from the peer and then set the header
field value itself. This ensures that the application only processes
identity material derived directly from the TLS session, enabling the
application to match the peer to the federation metadata and apply
authorization policy based on federation metadata claims. Header
fields that are not used to convey identity material are unaffected
by this requirement. The communication channel between the
intermediary and the application MUST provide integrity protection
and endpoint authentication to prevent tampering with forwarded peer
identity material.
Implementations SHOULD, when possible, rely on libraries with built-
in support for pinning. libcurl, for example, supports pinning via
the CURLOPT_PINNEDPUBLICKEY option. In Python, the cryptography
library can extract public keys, and application code can compare the
derived pin to a configured value. Go provides crypto/tls and
crypto/x509 for certificate inspection and public key extraction. In
Java, java.security.cert.X509Certificate enables public key
extraction, while java.net.http.HttpClient allows pinning enforcement
using a custom SSLContext and TrustManager. The choice of library is
left to the discretion of each implementation.
6. Federation Metadata
Federation metadata is published as a JSON Web Signature (JWS)
[RFC7515]. The payload contains statements about entities of
federation members.
Metadata is used for authentication and service discovery. A client
selects a server based on metadata claims, such as organization and
tags. To establish a connection, the client uses the base_uri, pins,
and, if needed, issuers of the selected server.
6.1. Federation Metadata Claims
This section defines the set of claims that can be included in
metadata.
* iat (REQUIRED)
Identifies the time at which the federation metadata was issued.
- Data Type: Integer
- Syntax: NumericDate as defined in [RFC7519], Section 4.1.6.
- Example: 1755514949
* exp (REQUIRED)
Identifies the expiration time on or after which the federation
metadata is no longer valid. Once the exp time has passed, the
metadata MUST be rejected regardless of cache state.
- Data Type: Integer
- Syntax: NumericDate as defined in [RFC7519], Section 4.1.4.
- Example: 1756119888
* iss (REQUIRED)
A URI uniquely identifying the issuing federation. This value
differentiates federations, prevents ambiguity, and ensures that
entities are recognized within their intended context.
Verification of the iss claim enables recipients to determine the
origin of the information and to establish trust with entities
within the identified federation.
- Data Type: String
- Syntax: StringOrURI as defined in [RFC7519], Section 4.1.1. In
MATF, this value MUST be a URI.
- Example: "https://federation.example.org"
* version (REQUIRED)
Indicates the schema version of the federation metadata. This
ensures compatibility between members of the federation by
defining a clear versioning mechanism for interpreting metadata.
- Data Type: String
- Syntax: The value MUST follow Semantic Versioning (see
<https://semver.org>).
- Example: "1.0.0"
* cache_ttl (OPTIONAL)
Specifies the duration in seconds for caching downloaded
federation metadata, allowing for independent caching outside of
specific HTTP configurations. This is particularly useful when
the communication mechanism is not based on HTTP. In the event of
a metadata publication outage, members can rely on cached metadata
until it expires, as indicated by the exp claim in the JWS
payload, defined in Section 6.1. Once expired, metadata MUST no
longer be trusted. If omitted, a mechanism to refresh metadata
MUST still exist to ensure the metadata remains valid.
- Data Type: Integer
- Syntax: Integer representing the duration in seconds.
- Example: 3600
* entities (REQUIRED)
Contains the list of entities within the federation.
- Data Type: Array of Objects
- Syntax: Each object MUST conform to the entity definition, as
specified in Section 6.1.1.
6.1.1. Entities
Metadata contains a list of entities that may be used for
communication within the federation. Each entity describes one or
more endpoints owned by a member. An entity has the following
properties:
* entity_id (REQUIRED)
A URI that uniquely identifies the entity. This identifier MUST
NOT collide with any other entity_id within the federation or
within any other federation that the entity interacts with.
- Data Type: String
- Syntax: A URI as defined in [RFC3986].
- Example: "https://example.com"
* organization (OPTIONAL)
A name identifying the organization that the entity's metadata
represents. The federation operator MUST ensure that a mechanism
is in place to verify that the organization claim corresponds to
the rightful owner of the information exchanged between nodes.
This is crucial for the trust model, ensuring certainty about the
identities of the involved parties. The federation operator
SHOULD choose an approach that best suits the specific needs and
trust model of the federation.
- Data Type: String
- Syntax: A name identifying the organization represented by the
entity.
- Example: "Example Org"
* issuers (REQUIRED)
A list of certificate issuers allowed to issue certificates for
the entity's endpoints. For each issuer, the issuer's root CA
certificate MUST be included in the x509certificate property and
be encoded using the Privacy-Enhanced Mail (PEM) format.
Certificate verification relies on public key pinning, with the
list of allowed issuers used only when a certificate chain
validation mechanism is unavoidable. For self-signed
certificates, the certificate itself acts as its own issuer and
MUST be listed as such in the metadata.
- Data Type: Array of Objects
- Syntax: Each object contains an issuer certificate encoded as
PEM, as specified in [RFC7468]. The Base64 content MUST be
wrapped so that each line consists of exactly 64 characters,
except for the final line. In JSON text, line breaks in the
PEM value are represented using the "\n" escape sequence.
- Example: Issuer truncated for readability.
"issuers": [{
"x509certificate": "-----BEGIN CERTIFICATE-----\nMIIDDD"
}]
* servers (OPTIONAL)
Contains the list of servers within the entity.
- Data Type: Array of Objects
- Syntax: Each object MUST conform to the server definition, as
specified in Section 6.1.1.1.
* clients (OPTIONAL)
Contains the list of clients within the entity.
- Data Type: Array of Objects
- Syntax: Each object MUST conform to the client definition, as
specified in Section 6.1.1.1.
6.1.1.1. Servers / Clients
The entity's servers and clients are listed below.
* description (OPTIONAL)
A human-readable text describing the server or client.
- Data Type: String
- Syntax: Free-form text describing the server or client.
- Example: "SCIM Server 1"
* base_uri (REQUIRED for servers, OPTIONAL for clients)
The base URL of the server. This claim is REQUIRED for server
endpoints. The value MUST be an absolute URI as defined in
Section 4.3 of [RFC3986]. The value serves as the base URI for
resolving relative references to server resources, as described in
Section 5 of [RFC3986].
- Data Type: String
- Syntax: An absolute URI as defined in Section 4.3 of [RFC3986]
that is used as a URL.
- Example: "https://scim.example.com/"
* pins (REQUIRED)
A list of objects representing public key pins [RFC7469].
- Data Type: Array of Objects
- Syntax: A list of objects, where each object represents a
single public key pin with the following properties:
o alg (REQUIRED)
The name of the cryptographic hash algorithm. Currently,
the RECOMMENDED value is 'sha256'. As more secure
algorithms are developed over time, federations should be
ready to adopt these newer options for enhanced security.
+ Data Type: String
+ Syntax: The name of the algorithm.
+ Example: "sha256"
o digest (REQUIRED)
The public key of the end-entity certificate, converted to a
Subject Public Key Information (SPKI) fingerprint, as
specified in Section 2.4 of [RFC7469]. For clients, the
digest value MUST be unique across entities in the
federation metadata to enable unambiguous identification of
the peer. Within the same entity, the same digest value MAY
be assigned to multiple clients.
+ Data Type: String
+ Syntax: SPKI fingerprint.
+ Example: "+hcmCjJEtLq4BRPhrILyhgn98Lhy6DaWdpmsBAgOLCQ="
- Example:
"pins": [{
"alg": "sha256",
"digest": "+hcmCjJEtLq4BRPhrILyhgn98Lhy6DaWdpmsBAgOLCQ="
}]
* tags (OPTIONAL)
A list of strings that describe the endpoint's capabilities.
- Data Type: Array of Strings
- Syntax: Strings describing endpoint capabilities.
- Pattern: ^[a-z0-9]{1,64}$
- Example: ["scim", "xyzzy"]
Tags are fundamental for discovery within a federation, aiding
both servers and clients in identifying appropriate connections.
- Server Tags: Tags associated with servers are used by clients
to discover servers offering the services they require.
Clients can search for servers based on tags that indicate
supported protocols or the type of data they handle, enabling
discovery of compatible servers.
- Client Tags: Tags associated with clients are used by servers
to identify clients with specific characteristics or
capabilities. For instance, a server might only accept
connections from clients that support particular protocols. By
filtering incoming requests based on these tags, servers can
identify suitable clients.
Federation-Specific Considerations: While tags are tied to
individual federations and serve distinct purposes within each,
several key considerations are crucial to ensure clarity and
promote consistent tag usage:
- Well-Defined Scope: Each federation MUST establish a clear
scope for its tags, detailing their intended use, allowed tag
values, associated meanings, and any relevant restrictions.
Maintaining a well-defined and readily accessible registry of
approved tags is essential for the federation.
- Validation Mechanisms: Implementing validation mechanisms for
tags is highly recommended. This can involve a dedicated
operation or service verifying tag validity and compliance with
the federation's regulations. Such validation ensures
consistency within the federation by preventing the use of
unauthorized or irrelevant tags.
6.2. Metadata Schema
The MATF metadata schema is defined in Appendix A. This schema
specifies the format for describing entities involved in MATF and
their associated information.
| Note: The schema in Appendix A is folded due to line length
| limitations as specified in [RFC8792].
6.3. Example Metadata
The following is a non-normative example of a metadata statement.
Line breaks in the example of the issuers claim are for readability
only.
{
"iat": 1755514949,
"exp": 1756119888,
"iss": "https://federation.example.org",
"version": "1.0.0",
"cache_ttl": 3600,
"entities": [{
"entity_id": "https://example.com",
"organization": "Example Org",
"issuers": [{
"x509certificate": "-----BEGIN CERTIFICATE-----\nMIIDDDCCAf
SgAwIBAgIJAIOsfJBStJQhMA0GCSqGSIb3DQEBCwUAMBsxGTAXBgNV\nBAM
MEHNjaW0uZXhhbXBsZS5jb20wHhcNMTcwNDA2MDc1MzE3WhcNMTcwNTA2MD
c1\nMzE3WjAbMRkwFwYDVQQDDBBzY2ltLmV4YW1wbGUuY29tMIIBIjANBgk
qhkiG9w0B\nAQEFAAOCAQ8AMIIBCgKCAQEAyr+3dXTC8YXoi0LDJTH0lTfv
8omQivWFOr3+/PBE\n6hmpLSNXK/EZJBD6ZT4Q+tY8dPhyhzT5RFZCVlrDs
e/kY00F4yoflKiqx9WSuCrq\nZFr1AUtIfGR/LvRUvDFtuHo1MzFttiK8Wr
wskMYZrw1zLHTIVwBkfMw1qr2XzxFK\njt0CcDmFxNdY5Q8kuBojH9+xt5s
ZbrJ9AVH/OI8JamSqDjk9ODyGg+GrEZFClP/B\nxa4Fsl04En/9GfaJnCU1
NpU0cqvWbVUlLOy8DaQMN14HIdkTdmegEsg2LR/XrJkt\nho16diAXrgS25
3xbkdD3T5d6lHiZCL6UxkBh4ZHRcoftSwIDAQABo1MwUTAdBgNV\nHQ4EFg
QUs1dXuhGhGc2UNb7ikn3t6cBuU34wHwYDVR0jBBgwFoAUs1dXuhGhGc2U\
nNb7ikn3t6cBuU34wDwYDVR0TAQH/BAUwAwEB/zANBgkqhkiG9w0BAQsFAA
OCAQEA\nrR9wxPhUa2XfQ0agAC0oC8TFf8wbTYb0ElP5Ej834xMMW/wWTSA
N8/3WqOWNQJ23\nf0vEeYQwfvbD2fjLvYTyM2tSPOWrtQpKuvulIrxV7Zz8
A61NIjblE3rfea1eC8my\nTkDOlMKV+wlXXgUxirride+6ubOWRGf92fgze
DGJWkmm/a9tj0L/3e0xIXeujxC7\nMIt3p99teHjvnZQ7FiIBlvGc1o8FD1
FKmFYd74s7RxrAusBEAAmBo3xyB89cFU0d\nKB2fkH2lkqiqkyOtjrlHPoy
6ws6g1S6U/Jx9n0NEeEqCfzXnh9jEpxisSO+fBZER\npCwj2LMNPQxZBqBF
oxbFPw==\n-----END CERTIFICATE-----"
}],
"servers": [{
"description": "SCIM Server 1",
"base_uri": "https://scim.example.com/",
"pins": [{
"alg": "sha256",
"digest": "+hcmCjJEtLq4BRPhrILyhgn98Lhy6DaWdpmsBAgOLCQ="
}],
"tags": [
"scim"
]
}],
"clients": [{
"description": "SCIM Client 1",
"pins": [{
"alg": "sha256",
"digest": "+hcmCjJEtLq4BRPhrILyhgn98Lhy6DaWdpmsBAgOLCQ="
}]
}]
}]
}
6.4. Metadata Signing
Federation metadata is signed using JWS and published using JWS JSON
Serialization according to the general JWS JSON Serialization syntax
defined in [RFC7515]. Federation metadata signatures are RECOMMENDED
to be created using the algorithm ECDSA using P-256 and SHA-256
("ES256") as defined in [RFC7518]. However, to accommodate evolving
cryptographic standards, alternative algorithms MAY be used, provided
they meet the security requirements of the federation.
Federations may need to transition to post-quantum (PQ) cryptographic
algorithms for federation metadata signatures and for endpoint
certificate public key types. MATF can accommodate such transitions
through key rollover and by updating published pins as new key types
are deployed.
The following JWS Protected Header parameters are REQUIRED:
* alg (Algorithm)
Identifies the algorithm used to generate the JWS signature
[RFC7515], Section 4.1.1.
* kid (Key Identifier)
Identifies the key in the issuer's key set that was used to
generate the JWS signature [RFC7515], Section 4.1.4.
6.5. Example Signature Protected Header
The following is a non-normative example of a signature protected
header.
{
"alg": "ES256",
"kid": "c2fb760e-f4b6-4f7e-b17a-7115d2826d51"
}
7. Example Usage Scenarios
The examples in this section are non-normative and illustrate the
procedures described in Section 5.2 and Section 5.3.
The following example describes a scenario within the federation
"Skolfederation" where MATF is deployed. Both clients and servers
are registered members of the federation. In this scenario, clients
manage cross-domain user accounts using SS 12000:2018, which is a
System for Cross-domain Identity Management (SCIM) extension.
+------------------------------------------------------+
| |
| Federation Metadata |
| |
+-----+-------------------------------+----------------+
| |
(A) (A)
| |
v v
+-----------+ +--------------------------------+
| Local MD | | Local MD |
+-----+-----+ +------+---------------------+---+
| | |
(B) (C) (F)
| | |
v v v
+-----------+ +--------------+ +-------+
| | | | | |
| Client +---(D)-->+ Intermediary +---(E)-->+ App |
| | | | | |
+-----------+ +--------------+ +-------+
A. Clients and servers retrieve federation metadata and update their
local metadata stores as described in Section 4.2.
B. The client selects a server endpoint based on metadata claims and
preloads the pins published for that endpoint.
C. If certificate chain validation is performed, the TLS client or
intermediary configures its trust store using the issuers listed
in the federation metadata for the selected entity.
D. The client initiates a TLS connection to the selected base_uri
and presents its client certificate.
E. If an intermediary terminates the TLS session, it forwards
identity material derived from the TLS session to the application
as described in Section 5.3 and Section 5.6.
F. The application maps the derived pin to a matching metadata entry
and uses the associated entity_id for identification and
authorization.
7.1. Client Behavior
A certificate is issued for the client. The client's certificate
issuer and public key pins are published in the federation metadata.
When a client initiates a connection to a remote server (identified
by the server's entity_id), the following steps are performed:
1. The client selects a server endpoint from the identified entity's
servers list whose tags match the required service capabilities.
2. The client preloads the selected endpoint's pins from its local
metadata store. If certificate chain validation is performed,
the client also loads the issuers listed for the entity.
3. The client initiates a TLS connection to the selected endpoint
using the base_uri and presents its client certificate.
4. The client performs pin validation for the server certificate as
described in Section 5.3. This validation may be performed by
the TLS stack during the handshake or by application logic after
the connection is established, but it completes before any
application data is exchanged.
5. If validation succeeds, the client proceeds with application
transactions.
7.2. Server Behavior
To accept inbound connections from a client, the server uses
federation metadata to perform pin validation of the public key in
the presented client certificate. The federation metadata publishes
client public key pins and, for deployments that perform certificate
chain validation, the allowed issuers.
When the server receives a TLS connection attempt from a remote
client, the following steps are performed:
1. The server is configured to request or require a client
certificate. If certificate chain validation is performed, the
trust store is populated using the issuers published in the
federation metadata. Otherwise, the server requests a client
certificate without issuer validation (for example,
optional_no_ca).
2. The server can prefilter the federation metadata to identify the
set of clients it is willing to communicate with and preload only
the pins for those clients, as described in Section 5.2.
3. After the TLS handshake completes, the server derives the
client's pin from the presented certificate and matches it
against the preloaded pins. When a match is found, the server
determines the client's entity_id from the corresponding metadata
entry.
4. If pin validation succeeds, the server proceeds with application
transactions. If pin validation fails, the server terminates the
connection.
7.3. SPKI Generation
The following is an example of how to use OpenSSL to generate a SPKI
fingerprint from a PEM-encoded certificate.
openssl x509 -in <certificate.pem> -pubkey -noout | \
openssl pkey -pubin -outform der | \
openssl dgst -sha256 -binary | \
openssl enc -base64
7.4. Curl and Public Key Pinning
The following is an example of public key pinning with curl.
curl --cert client.pem --key client.key \
--pinnedpubkey \
'sha256//0Ok2aNfcrCNDMhC2uXIdxBFOvMfEVtzlNVUT5pur0Dk=' \
https://host.example.com
8. Deployments of the MATF Framework
The MATF framework has proven its practical value and robustness
through successful deployments in several environments.
8.1. Skolfederation Moa
Skolfederation Moa [Moa] is a federation designed to secure
communication between digital educational resources and schools.
MATF was developed to meet Moa's needs and enables secure data
exchange for schools, municipalities, educational platforms, and
services across Sweden.
The community plays a crucial role in this type of federation.
Members are active participants, and the federation operator ensures
the federation runs smoothly and serves their needs. Moa's success
highlights the importance of collaboration, with members and the
federation operator working together to maintain trust, security, and
interoperability in the education sector.
The deployment of MATF in the Swedish education sector has provided
several key insights. Maintaining an accurate registry of metadata
ownership with reliable contact information is essential for
troubleshooting and ensuring accountability. The deployment also
demonstrated the importance of setting reasonable expiration times
for metadata. Too short an expiration can hinder the ability to
implement contingency plans for publishing new metadata during
outages.
Metadata validation is necessary to maintain a stable federation.
While manual validation may be sufficient in the early stages of a
federation, it becomes unmanageable as the federation scales.
Without an automated validation process, incorrect metadata uploaded
by members is likely to go undetected, leading to publication of
incorrect metadata.
The federation metadata signing private key is required to publish
signed federation metadata. In fallback scenarios, federation
metadata may be retrieved from an alternate location, but publishing
updated federation metadata requires access to the signing private
key. Therefore, secure and redundant management of the signing
private key is necessary to support fallback mechanisms and reliable
publication. Recipients MUST validate the JWS signature using the
federation signature verification key before using federation
metadata, regardless of where it is obtained.
8.2. Swedish National Agency for Education
The Swedish National Agency for Education [SkolverketMATF] leverages
MATF within its digital national test platform to establish a robust
authentication mechanism. The platform utilizes an API for client
verification prior to secure data transfer to the agency's test
service, ensuring the integrity and confidentiality of educational
data.
8.3. Sambruk's EGIL
Sambruk's EGIL [EGIL], a platform providing digital services to
municipalities, has successfully integrated the MATF framework. This
deployment demonstrates the framework's adaptability to support a
wide range of digital service infrastructures.
These deployments highlight the effectiveness of the MATF framework
in enhancing security and interoperability within the educational
sector.
9. Security Considerations
9.1. Security Risks and Trust Management
The security risks associated with the MATF framework are confined to
each individual federation. Both the federation operator and
federation members share the responsibility of maintaining trust and
security. Proper handling of metadata and thorough vetting of
members are crucial to sustaining this trust.
Deployments that terminate a session at an intermediary and convey
identity material to an application introduce a critical trust
boundary. If the intermediary is compromised or fails to properly
sanitize inbound headers, an attacker could spoof a peer's entity_id.
Therefore, intermediaries that convey identity material to an
application MUST comply with the requirements in Section 5.6.
Implementations SHOULD avoid logging conveyed certificates, pins, or
identity values unless required for diagnostics to prevent the
accidental exposure of session-specific identity material.
9.2. TLS
The security considerations for TLS 1.3 are detailed in Section 10
and Appendices C, D, and E of [RFC8446].
9.3. Federation Metadata Updates
Regularly updating the local copy of federation metadata is essential
for accessing the latest information about active entities, current
public key pins [RFC7469], and valid issuer certificates. The use of
outdated metadata may expose systems to security risks, such as
interaction with revoked entities or acceptance of manipulated data.
9.4. Verifying the Federation Metadata Signature
Ensuring data integrity and security within the MATF framework relies
on verifying the signature of downloaded federation metadata. This
verification confirms the origin of the metadata by validating the
JWS signature using the federation signature verification key trusted
by the recipient. It also confirms that the signed content has not
been altered by unauthorized parties. By verifying the signature,
trust is maintained in the integrity of the information used for
validation, including member public key pins and issuer certificates.
To achieve a robust implementation, it is important to consider the
security aspects outlined in [RFC7515], which describes security
considerations related to algorithm selection, key compromise, and
signature integrity.
9.5. Time Synchronization
Maintaining synchronized clocks across all federation members is
critical for the security of the MATF framework. Inaccurate
timestamps can compromise the validity of digital signatures and
certificates, hinder reliable log analysis, and potentially expose
the system to time-based attacks. Therefore, all federation members
MUST employ methods to ensure their system clocks are synchronized
with a reliable time source.
10. IANA Considerations
This document has no IANA actions.
11. References
11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC7468] Josefsson, S. and S. Leonard, "Textual Encodings of PKIX,
PKCS, and CMS Structures", RFC 7468, DOI 10.17487/RFC7468,
April 2015, <https://www.rfc-editor.org/info/rfc7468>.
[RFC7469] Evans, C., Palmer, C., and R. Sleevi, "Public Key Pinning
Extension for HTTP", RFC 7469, DOI 10.17487/RFC7469, April
2015, <https://www.rfc-editor.org/info/rfc7469>.
[RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May
2015, <https://www.rfc-editor.org/info/rfc7515>.
[RFC7517] Jones, M., "JSON Web Key (JWK)", RFC 7517,
DOI 10.17487/RFC7517, May 2015,
<https://www.rfc-editor.org/info/rfc7517>.
[RFC7518] Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
DOI 10.17487/RFC7518, May 2015,
<https://www.rfc-editor.org/info/rfc7518>.
[RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
(JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
<https://www.rfc-editor.org/info/rfc7519>.
[RFC7638] Jones, M. and N. Sakimura, "JSON Web Key (JWK)
Thumbprint", RFC 7638, DOI 10.17487/RFC7638, September
2015, <https://www.rfc-editor.org/info/rfc7638>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
11.2. Informative References
[eduGAIN] eduGAIN, "eduGAIN: Interfederation service connecting
research and education identity federations worldwide",
<https://edugain.org>.
[EGIL] Sambruk, "EGIL – smidig hantering av skolans digitala
användarkonton" [EGIL – manage your school's digital user
accounts efficiently], <https://sambruk.se/egil-dnp/>.
[eIDAS] European Union, "Regulation (EU) No 910/2014 of the
European Parliament and of the Council of 23 July 2014 on
electronic identification and trust services for
electronic transactions in the internal market", Official
Journal of the European Union L 257/73,
ELI http://data.europa.eu/eli/reg/2014/910/oj, 23 July
2014, <https://eur-lex.europa.eu/eli/reg/2014/910/oj/eng>.
[Moa] Internetstiftelsens Federationer [The Swedish Internet
Foundation], "Machine and Organization Authentication", 6
October 2025,
<https://wiki.federationer.internetstiftelsen.se/x/
LYA5AQ>.
[RFC8792] Watsen, K., Auerswald, E., Farrel, A., and Q. Wu,
"Handling Long Lines in Content of Internet-Drafts and
RFCs", RFC 8792, DOI 10.17487/RFC8792, June 2020,
<https://www.rfc-editor.org/info/rfc8792>.
[SkolverketMATF]
Skolverket [Swedish National Agency for Education], "API
för autentisering" [Authentication API for User
Management], commit f8c2e93, 4 September 2025,
<https://github.com/skolverket/dnp-
usermanagement/blob/main/authentication-api/README.md>.
Appendix A. JSON Schema for MATF Metadata
The following JSON Schema defines the structure of MATF metadata. It
conforms to draft 2020-12 of the JSON Schema standard.
Version: 1.0.0
=============== NOTE: '\\' line wrapping per RFC 8792 ===============
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://mtlsfed.se/schema/matf-metadata-schema.json",
"title": "JSON Schema for Mutually Authenticating TLS in the con\
\text of Federations",
"description": "Version: 1.0.0",
"type": "object",
"additionalProperties": true,
"required": [
"iat",
"exp",
"iss",
"version",
"entities"
],
"properties": {
"iat": {
"title": "Issued at",
"description": "Time at which the metadata was issued (U\
\NIX timestamp)",
"type": "integer",
"minimum": 0,
"examples": [
1755514949
]
},
"exp": {
"title": "Expiration time",
"description": "Time at which the metadata expires (UNIX\
\ timestamp)",
"type": "integer",
"minimum": 0,
"examples": [
1756119888
]
},
"iss": {
"title": "The federation issuing the metadata",
"description": "A URI that uniquely identifies the feder\
\ation that issued the metadata",
"type": "string",
"format": "uri",
"minLength": 1,
"examples": [
"https://example.com/federation"
]
},
"version": {
"title": "Metadata schema version",
"description": "Schema version follows semantic versioni\
\ng (https://semver.org)",
"type": "string",
"pattern": "^\\d+\\.\\d+\\.\\d+$",
"examples": [
"1.0.0"
]
},
"cache_ttl": {
"title": "Metadata cache TTL",
"description": "How long in seconds to cache metadata. T\
\he effective maximum is bounded by the exp claim.",
"type": "integer",
"minimum": 0,
"examples": [
3600
]
},
"entities": {
"type": "array",
"minItems": 1,
"items": {
"$ref": "#/$defs/entity"
}
}
},
"$defs": {
"entity": {
"type": "object",
"additionalProperties": true,
"required": [
"entity_id",
"issuers"
],
"properties": {
"entity_id": {
"title": "Entity identifier",
"description": "Globally unique identifier for t\
\he entity.",
"type": "string",
"format": "uri",
"examples": [
"https://example.com"
]
},
"organization": {
"title": "Name of entity organization",
"description": "Name identifying the organizatio\
\n that the entity's metadata represents.",
"type": "string",
"examples": [
"Example Org"
]
},
"issuers": {
"title": "Entity certificate issuers",
"description": "A list of certificate issuers th\
\at are allowed to issue certificates for the entity's endpoints. Fo\
\r each issuer, the issuer's root CA certificate is included in the \
\x509certificate property (PEM-encoded).",
"type": "array",
"minItems": 1,
"items": {
"$ref": "#/$defs/cert_issuers"
}
},
"servers": {
"type": "array",
"items": {
"$ref": "#/$defs/endpoint"
}
},
"clients": {
"type": "array",
"items": {
"$ref": "#/$defs/endpoint"
}
}
}
},
"endpoint": {
"type": "object",
"additionalProperties": true,
"required": [
"pins"
],
"properties": {
"description": {
"title": "Endpoint description",
"type": "string",
"examples": [
"SCIM Server 1"
]
},
"tags": {
"title": "Endpoint tags",
"description": "A list of strings that describe \
\the endpoint's capabilities.",
"type": "array",
"items": {
"type": "string",
"pattern": "^[a-z0-9]{1,64}$",
"examples": [
"xyzzy"
]
}
},
"base_uri": {
"title": "Endpoint base URI",
"type": "string",
"format": "uri",
"examples": [
"https://scim.example.com"
]
},
"pins": {
"title": "Certificate pin set",
"type": "array",
"minItems": 1,
"items": {
"$ref": "#/$defs/pin_directive"
}
}
}
},
"cert_issuers": {
"title": "Certificate issuers",
"type": "object",
"additionalProperties": false,
"required": [
"x509certificate"
],
"properties": {
"x509certificate": {
"title": "X.509 Certificate (PEM)",
"type": "string",
"pattern": "^-----BEGIN CERTIFICATE-----(?:\\r?\\
\\n)(?:[A-Za-z0-9+/=]{64}\\r?\\n)*(?:[A-Za-z0-9+/=]{1,64}\\r?\\n)---\
\--END CERTIFICATE-----(?:\\r?\\n)?$"
}
}
},
"pin_directive": {
"title": "RFC 7469 pin directive",
"type": "object",
"additionalProperties": false,
"required": [
"alg",
"digest"
],
"properties": {
"alg": {
"title": "Directive name",
"type": "string",
"enum": [
"sha256"
],
"examples": [
"sha256"
]
},
"digest": {
"title": "Directive value (Base64)",
"type": "string",
"pattern": "^[A-Za-z0-9+/]{43}=$",
"examples": [
"HiMkrb4phPSP+OvGqmZd6sGvy7AUn4k3XEe8OMBrzt8\
\="
]
}
}
}
}
}
Acknowledgements
This project was funded through the NGI0 PET Fund, a fund established
by NLnet with financial support from the European Commission's Next
Generation Internet programme, under the aegis of DG Communications
Networks, Content and Technology under grant agreement No 825310.
The authors thank the following people for the detailed review and
suggestions:
* Rasmus Larsson
* Mats Dufberg
* Joe Siltberg
* Stefan Norberg
* Petter Blomberg
The authors would also like to thank participants in the EGIL working
group for their comments on this specification.
Authors' Addresses
Stefan Halén
The Swedish Internet Foundation
Email: stefan.halen@internetstiftelsen.se
Jakob Schlyter
Kirei AB
Email: jakob@kirei.se