stacklok / toolhive / 32058323050

70%

Build Type

push

github

Committed by web-flow

Commit Message

Support actor_token in RFC 8693 token exchange (#6331)

* Support actor_token and id_token in RFC 8693 token exchange

An agent calling the token-exchange grant could previously only be
identified by its own OAuth client credentials at the endpoint. RFC
8693 also defines an explicit actor_token: a second, self-issued JWT
the agent presents alongside the user's subject_token, giving the
exchange a request-level proof of possession distinct from client
authentication. The handler unconditionally rejected both actor_token
and actor_token_type before this change ("not yet supported"), and
only accepted urn:...:access_token/jwt as subject_token_type, so a
subject token minted as an OIDC id_token (a legitimate shape from many
IdPs) had no way to be exchanged.

What changed:
- Accept actor_token + actor_token_type instead of rejecting them
  outright. resolveActorIdentity validates actor_token against the
  server's own JWKS (self-issued only — an actor_token is never
  accepted from an external trusted issuer) and requires its "sub" to
  equal the authenticated client's ID before the exchange proceeds.
- Accept id_token as a valid subject_token_type value.
- Removed the now-superseded validateExchangeParams helper (the old,
  actor_token-rejecting parameter validator) in favor of the new
  validateFormParams/resolveActorIdentity split.
- Corrected docs/arch/token-delegation-act-chain.md, which still
  described RFC 8693's chained-act-claim nesting as "not implemented"
  — that landed separately in #6149 before this branch was rebased;
  the doc had gone stale, not the behavior.
- Added an integration test proving actor_token composes correctly
  with the configured-delegate-client relaxation (a client granted
  blanket self-issued-token trust): a mismatched actor_token must
  still be rejected during actor-identity resolution before delegation
  consent is ever reached, so that blanket trust can never be misread
  as also loosening the actor_token binding c... (continued)

Coverage Stats

91 of 93 new or added lines in 3 files covered. (97.85%)

20 existing lines in 6 files now uncovered.

85214 of 121079 relevant lines covered (70.38%)

97.37 hits per line