Disclaimer:
This document is a work in progress and subject to further refinements and updates. Please note that some details may change as new requirements emerge or as part of ongoing development. Feedback and suggestions for improvement are welcome.



This guide explains how to connect your issuer to an OpenID Federation (OIDF) trust framework. It includes details on configuring the authority_hints, trust_marks, federation info endpoint, and trust_anchors using specific values provided for the test environment.

Prerequisites

Before proceeding, ensure the following are in place:


Key Configuration Points

Federation Entity Configuration Information

The configuration endpoint publishes the Entity Configuration document, detailing the issuer’s configuration information for federation participants.

  1. Define the Endpoint:

  2. Implementation:

  3. Example Entity Configuration: Here is an example of Entity Configuration that can be exposed at the endpoint: 

    {
        "sub": "https://my-issuer.example.com:8000",
        "metadata": {
            "federation_entity": {
                "organization_name": "The OP operator",
                "contacts": "operations@op.example.com"
            },
            "oauth_authorization_server": {
                "jwks_uri": "https://my-issuer.example.com:8000/jwks/oauth_authorization_server",
                "token_endpoint_auth_methods_supported": [],
                "token_endpoint_auth_signing_alg_values_supported": [
                    "RS256",
                    "RS384",
                    "RS512",
                    "ES256",
                    "ES256K",
                    "ES384",
                    "ES512",
                    "PS256",
                    "PS384",
                    "PS512",
                    "HS256",
                    "HS384",
                    "HS512",
                    "Ed25519",
                    "Ed448",
                    "EdDSA"
                ],
                "response_types_supported": [
                    "code"
                ],
                "response_modes_supported": [
                    "code"
                ],
                "acr_values_supported": [],
                "scopes_supported": [],
                "authorization_signing_alg_values_supported": [
                    "RS256",
                    "RS384",
                    "RS512",
                    "ES256",
                    "ES256K",
                    "ES384",
                    "ES512",
                    "PS256",
                    "PS384",
                    "PS512",
                    "HS256",
                    "HS384",
                    "HS512",
                    "Ed25519",
                    "Ed448",
                    "EdDSA"
                ],
                "request_object_signing_alg_values_supported": [
                    "RS256",
                    "RS384",
                    "RS512",
                    "ES256",
                    "ES256K",
                    "ES384",
                    "ES512",
                    "PS256",
                    "PS384",
                    "PS512",
                    "HS256",
                    "HS384",
                    "HS512",
                    "Ed25519",
                    "Ed448",
                    "EdDSA"
                ],
                "claims_parameter_supported": true,
                "request_parameter_supported": true,
                "request_object_encryption_alg_values_supported": [],
                "request_object_encryption_enc_values_supported": [],
                "code_challenge_methods_supported": [
                    "plain",
                    "S256",
                    "S384",
                    "S512"
                ],
                "deny_unknown_scopes": false,
                "ui_locales_supported": [],
                "token_endpoint": "https://my-issuer.example.com:8000/token",
                "token_endpoint_auth_methods": [
                    "attest_jwt_client_auth"
                ],
                "authorization_endpoint": "https://my-issuer.example.com:8000/authorization",
                "authorization_endpoint_auth_methods": [
                    "pushed_authz"
                ],
                "pushed_authorization_request_endpoint": "https://my-issuer.example.com:8000/par",
                "pushed_authorization_request_endpoint_auth_methods": [
                    "attest_jwt_client_auth"
                ]
            },
            "openid_credential_issuer": {
                "attribute_disclosure": {
                    "": [
                        "given_name",
                        "family_name",
                        "name",
                        "email",
                        "nickname"
                    ]
                },
                "credential_configurations_supported": {
                    "PDA1Credential": {
                        "format": "vc+sd-jwt",
                        "id": "eudiw.pda1.se",
                        "cryptographic_binding_methods_supported": [
                            "jwk"
                        ],
                        "cryptographic_suites_supported": [
                            "RS256",
                            "RS512",
                            "ES256",
                            "ES512"
                        ],
                        "display": {
                            "name": "Swedish PDA1 Provider Example",
                            "locale": "en-US"
                        },
                        "vct": "PDA1Credential",
                        "credential_definition": {
                            "type": [
                                "PDA1Credential"
                            ],
                            "credentialSubject": {
                                "family_name": {
                                    "display": [
                                        {
                                            "locale": "en-US",
                                            "name": "Current Family Name"
                                        }
                                    ],
                                    "mandatory": true
                                },
                                "given_name": {
                                    "display": [
                                        {
                                            "locale": "en-US",
                                            "name": "Current First Name"
                                        }
                                    ],
                                    "mandatory": true
                                },
                                "birth_date": {
                                    "display": [
                                        {
                                            "locale": "en-US",
                                            "name": "Birth date"
                                        }
                                    ]
                                }
                            }
                        }
                    },
                    "EHICCredential": {
                        "format": "vc+sd-jwt",
                        "id": "eudiw.ehic.se",
                        "cryptographic_binding_methods_supported": [
                            "jwk"
                        ],
                        "cryptographic_suites_supported": [
                            "RS256",
                            "RS512",
                            "ES256",
                            "ES512"
                        ],
                        "display": {
                            "name": "Swedish EHIC Provider Example",
                            "locale": "en-US"
                        },
                        "vct": "EHICCredential",
                        "credential_definition": {
                            "type": [
                                "EHICCredential"
                            ],
                            "credentialSubject": {
                                "family_name": {
                                    "display": [
                                        {
                                            "locale": "en-US",
                                            "name": "Current Family Name"
                                        }
                                    ],
                                    "mandatory": true
                                },
                                "given_name": {
                                    "display": [
                                        {
                                            "locale": "en-US",
                                            "name": "Current First Name"
                                        }
                                    ],
                                    "mandatory": true
                                },
                                "birth_date": {
                                    "display": [
                                        {
                                            "locale": "en-US",
                                            "name": "Birth date"
                                        }
                                    ]
                                }
                            }
                        }
                    }
                },
                "jwks": {
                    "keys": [
                        {
                            "kty": "RSA",
                            "use": "sig",
                            "kid": "ODR1b1ZjUEpsRzVhVHBSaWxLR1hxQ2x3WTU2ZVFDcnVsMXBmdEF5WUM4UQ",
                            "e": "AQAB",
                            "n": "vqLXJgOHZn7YFqL78Kth6vP..."
                        },
                        {
                            "kty": "EC",
                            "use": "sig",
                            "kid": "YzIwZjJEaFJxU0NOLXJ5MS1mSXgyLUp5RWNZb3I4M1lRMDVhQWxMUjhsZw",
                            "crv": "P-256",
                            "x": "FdYslsTybViEudE4T-gyBrcKeZNleH9-QajFYVpOYW8",
                            "y": "If-rr6KWEEnC_R8N93SrcQRn4E7lC4WXOqgANj-o0UE"
                        },
                        {
                            "kty": "EC",
                            "kid": "default_signing_key_id",
                            "crv": "P-256",
                            "x": "-i8_UtCwdCic10eDuNwr68IEHWk4B1HSn119fdNT-pQ",
                            "y": "UIMFXTj4kOWF2gZaKDTP3n3K-08TfkLHw8hIV6bOxqw"
                        },
                        {
                            "kty": "EC",
                            "kid": "default_signing_key_id",
                            "crv": "P-256",
                            "x": "-i8_UtCwdCic10eDuNwr68IEHWk4B1HSn119fdNT-pQ",
                            "y": "UIMFXTj4kOWF2gZaKDTP3n3K-08TfkLHw8hIV6bOxqw"
                        }
                    ]
                },
                "credential_response_encryption_alg_values_supported": [
                    "RSA1_5",
                    "RSA-OAEP",
                    "RSA-OAEP-256",
                    "A128KW",
                    "A192KW",
                    "A256KW",
                    "ECDH-ES",
                    "ECDH-ES+A128KW",
                    "ECDH-ES+A192KW",
                    "ECDH-ES+A256KW"
                ],
                "credential_response_encryption_enc_values_supported": [
                    "A128CBC-HS256",
                    "A192CBC-HS384",
                    "A256CBC-HS512",
                    "A128GCM",
                    "A192GCM",
                    "A256GCM"
                ],
                "require_credential_response_encryption": false,
                "credentials_supported": [
                    "vp_token"
                ],
                "credential_endpoint": "https://my-issuer.example.com:8000/credential",
                "credential_endpoint_auth_methods": [
                    "dpop_client_auth"
                ]
            }
        },
        "authority_hints": [
            "https://trust-anchor.example.com:7001"
        ],
        "trust_marks": [
            "eyJhbGciOiJSUzI1Ni...",
            "eyJhbGciOiJSUzI1N..."
        ],
        "jwks": {
            "keys": [
                {
                    "kty": "RSA",
                    "use": "sig",
                    "kid": "VmhPQndmVDNja09ZYTQ4UlM3eWl2Z3BxMlp1cVd1ZFB1YnhwdWUxa3p4Zw",
                    "e": "AQAB",
                    "n": "y68Zlt9DHIXHvH3HMFtY..."
                },
                {
                    "kty": "EC",
                    "use": "sig",
                    "kid": "dTlESU50RVVjVDA3eWFPV0dMQ2taMC0tbDlWclBjQTBUdkpyNlVhSVBfOA",
                    "crv": "P-256",
                    "x": "IqpTNpOAXTsQVVlO18zzAV1rHI36qBvZv7VbdtniV-c",
                    "y": "JozJQWmYCkvxD4PtUnr6sKXRL8SOj7ggx6WHzQxHgaw"
                }
            ]
        },
        "iss": "https://my-issuer.example.com:8000",
        "iat": 1732718163,
        "exp": 1732804563
    }



Trust Anchors

The Trust Anchor (TA) is the root of the federation’s trust chain.

  1. Trust Anchor URL:

  2. Trust Anchor Keys: Add the Trust Anchor’s  and public keys to your configuration: 

    trust_anchors:
      https://openidfed-test-1.sunet.se:7001:
        keys:
          - kty: RSA
            use: sig
            kid: UFpoajluZU42dTNUUXo5RnhBVEJnRk9JY2NtU1JKdlVYUk1RUFRyVkFFRQ
            n: p9S2whcSjmBdxerp80tIJreUUmZiGNGXIocJlNjx9pgD5_WD2l6mBNuEZMpP-QUB_TSV3VesNiqmOdydGp1wkfQ-NmVdoso29FjEdgrckLIwirAVmVQ6bGQQnXJrR56mRz0QqENi11vVpbDj6hsprxK1EZBQL-sQ2kem289B_BCNT-NvwVHrYJlaQA32z7cs1a7W8wt9eLxA10PeiYMgDVU_69wKBw4YrjjozOHKMRGchUQEjQhfSZfk49bip_5TNz4dmBmSCIbdE2yilFrfRSNrh7q2myuyDE3k2QZbSOXXGGT1LtHO74WIY58v-M3A7_zxp0f2Eo9ZD3N4h-InIw
            e: AQAB
          - kty: EC
            use: sig
            kid: Nm82cTJKMDkydXhxOUMtTm0teFpMWlZiR0ZVa2U3YVVtbkJTV3hBd3FqOA
            crv: P-256
            x: 69XlQkKYfWJDXAv_Vbrqyfz9gfAhu1qQ4mtLde18-Cg
            y: ntBwdhy4_cS2PRBS-xdKkNwcO1yQP8TdoOHbHN9Yjv8


  3. Purpose: Trust Anchors validate Trust Marks’ signatures and establish trust within the federation.


Registering the Issuer as a Subordinate Entity

In an OpenID Federation trust framework, the Issuer must be added as a Subordinate Entity under a Superior Entity (e.g., a Trust Anchor or an Intermediate Entity). This process ensures that the Issuer is recognized as part of the trust hierarchy.

Key Steps for the Issuer Operator


Authority Hints

The authority_hints parameter specifies the URL of the Intermediate Entities or Trust Anchors that are Immediate Superiors of the Entity. This helps other federation participants understand upstream trust relationships.

  1. Add to Configuration: Add authority_hints in your issuer’s metadata configuration: 

    authority_hints:
      - "https://openidfed-test-1.sunet.se:7001"

  2. Purpose: This parameter establishes hierarchical trust relationships from your issuer to the Trust Anchor.


Trust Marks

Trust Marks are JWTs issued by a Trust Mark Issuer to validate compliance with federation policies.

Types of Trust Marks

The following Trust Marks are available for issuance:

Retrieving Trust Marks

  1. Inputs to Trust Mark Issuer:

  2. Steps:

  3. Validation:

  4. Include in Metadata: Add issued Trust Marks to your issuer’s metadata:

    trust_marks:
      - "eyJhbGciOiJIUzI1NiIsInR..."
      - "eyJhbGciOiJIUzI1NiIsInR..."


How to Add Trust Marks to the vc_up_and_running Issuer

To update the Trust Marks, you need to modify the trust_marks section of the satosa/plugins/oidc_frontend.yaml file. Follow the steps below to replace the existing Trust Marks with the ones received from the federation operator.

  1. Locate the Trust Marks Section

    In the current configuration, the `trust_marks` are defined under: 

    trust_marks:
      - <existing-trust-mark-1>
      - <existing-trust-mark-2>

    You need to replace these values with the new Trust Marks provided by the federation operator.

  2. Example Update 

    If the federation operator provided the following new Trust Marks:

    eyJhbGciOiJSUzI1NiIsImtpZCI6IjM2NWQ2MjY3LTI5MzQtNGJhNy05YjEyLWU4ZmFkNTYwYjZjMyJ9...
    eyJhbGciOiJSUzI1NiIsImtpZCI6IjkwNTFjZTgzLTY1NzEtNDliYi04ODdjLTc3OWQzMDNmOTRmYyJ9...

    Modify the `trust_marks` section as follows: 

    trust_marks:
      - eyJhbGciOiJSUzI1NiIsImtpZCI6IjM2NWQ2MjY3LTI5MzQtNGJhNy05YjEyLWU4ZmFkNTYwYjZjMyJ9...
      - eyJhbGciOiJSUzI1NiIsImtpZCI6IjkwNTFjZTgzLTY1NzEtNDliYi04ODdjLTc3OWQzMDNmOTRmYyJ9..


  3. Restart the Issuer to Apply Changes

    Once you've updated the configuration file, restart the Issuer container to apply the changes: 

    ./stop.sh && \
    ./start.sh


  4. Verify the Changes
    After restarting SATOSA, verify that the new Trust Marks are correctly applied:

    curl -k -s https://<issuer-host>:8000/.well-known/openid-federation | cut -d '.' -f2 | tr '_-' '/+' | base64 -d 2>/dev/null | jq .

    Look for the updated `trust_marks` in the JSON response.

Testing Trust Marks

  1. Decode JWT: Use tools like jwt.io to inspect the Trust Mark's claims and ensure all required fields are present.

  2. Verify Signature: Validate the JWT signature against the Trust Mark Issuer's public key.

  3. Check Expiration: Ensure the exp claim (if present) has not expired.

  4. Validate References: Follow the ref URL (if provided) to confirm compliance with human-readable policy documents.


Steps to Connect the Issuer

  1. Configure the Issuer:

  2. Register with the Federation:

  3. Validate Configuration:

  4. Monitor the Connection:


Testing the Trust Relationships

  1. Validate Trust Marks: Use tools like jwt.io to decode and verify Trust Marks using the Trust Anchor's public keys.

  2. Retrieve Metadata: Ensure the .well-known/openid-federation endpoint correctly serves the issuer’s metadata: 

    curl -X GET https://your-issuer.example.com/.well-known/openid-federation

  3. Check Authority Hints: Verify that authority_hints points to the correct Trust Anchor: 

    authority_hints:
      - "https://openidfed-test-1.sunet.se:7001"
    
    
  4. Validate Public Keys: Confirm that the Trust Anchor’s public keys match the ones provided in the configuration.