accessPhase 4

Federated Authorization Access (4-party)

The resource has its own access server. The agent obtains a person token from its PS, presents it at the resource's authorization endpoint, and gets back a resource token whose aud is the AS URL. The PS federates with the AS — sending the resource token and the agent token — and the AS evaluates resource policy and issues the auth token. Only the PS may call the AS token endpoint, which is why a resource token issued to an agent that cannot name a person is one nobody can redeem.

§ Federated Authorization Access (Four-Party)

POST https://ps.example/person200

The agent signs with its agent token and names the resource it wants a person token for. resource is REQUIRED and becomes the token's aud.

The PS issues aa-person+jwt with a directed sub for that resource and cnf.jwk bound to the agent's signing key.

A person token carries no scope and no account — it identifies the person, it does not authorize anything.

The PS MAY require the person's approval first and return 202 with requirement=interaction.

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speed

Step 1: POST /person {resource} → 200 person_token

Request / response

Token Lifecycle

Person Tokenaa-person+jwt

Resource Tokenaa-resource+jwt

Auth Tokenaa-auth+jwt

Agent Tokenaa-agent+jwt

POSThttps://ps.example/person

Host

ps.example

Content-Type?

application/json

Content-Digest

sha-256=:X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=:

Signature-KeyAAuth?

sig=jwt;jwt="eyJhbGciOiJFZERTQSIsImtpZCI6ImFnZW50LWtleS0xIiwidHlwIjoiYWEtYWdlbnQ…

Signature-InputAAuth?

sig=("@method" "@authority" "@path" "content-type" "content-digest" "signature-k…

SignatureAAuth?

sig=:U2lnbmF0dXJlQnl0ZXNFeGFtcGxlVmFsdWVGb3JEZW1vbnN0cmF0aW9uUHVycG9zZXNPbmx5:

Body

{
  "resource": "https://api.example"
}

HTTP Signaturescheme=jwt

Covered Components

@method

@authority

@path

content-type

content-digest

signature-key

Signature Base

"@method": POST

"@authority": ps.example

"@path": /person

"content-type": application/json

"content-digest": sha-256=:X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=:

"signature-key": sig=jwt;jwt="eyJhbGciOiJFZERTQSIsImtpZCI6ImFnZW50LWtleS0xIiwidHlwIjoiYWEtYWdlbnQrand0In0…"

"@signature-params": ("@method" "@authority" "@path" "content-type" "content-digest" "signature-key");created=1700000000;alg="ed25519"

Signature-Key Header

sig=jwt;jwt="eyJhbGciOiJFZERTQSIsImtpZCI6ImFnZW50LWtleS0xIiwidHlwIjoiYWEtYWdlbnQrand0In0…"

Signature-Input Header

sig=("@method" "@authority" "@path" "content-type" "content-digest" "signature-key");created=1700000000;alg="ed25519"

Person Tokenaa-person+jwt

Header

{"alg":"EdDSA",
"kid":"ps-key-1",
"typ"?Token type identifier. aa-agent+jwt = Agent Token, aa-person+jwt = Person Token, aa-resource+jwt = Resource Token, aa-auth+jwt = Auth Token:"aa-person+jwt"
}

Payload

{"iss"?Issuer — who created and signed this token:"https://ps.example",
"dwk"?Discovery Well-Known — the metadata document name for key discovery (e.g. aauth-agent.json, aauth-person.json):"aauth-person.json",
"aud"?Audience — which party should accept this token:"https://api.example",
"sub"?Subject. In an agent token, the agent identifier. In a person, resource or auth token, the person's directed identifier — opaque, unique within the issuer. Identity is the pair (iss, sub); a sub from one issuer MUST NOT be matched against a record established under another.:"8f14e45fceea167a5a36dedd4bea2543",
"cnf"?Confirmation — proof-of-possession claim binding this token to a key:{"jwk"?JSON Web Key — the public key bound to this token:
},
"jti"?JWT ID — unique identifier for this token (replay detection, audit, revocation):"pt-32d653",
"iat"?Issued At — Unix timestamp when the token was created:1776222894,
"exp"?Expiration — Unix timestamp after which the token is invalid:1776226494
}

sig: cGVyc29uVG9rZW5TaWduYXR1cmVJc3N1…