trust-tasks-tsp 0.4.0

ToIP Trust Spanning Protocol (TSP) transport binding for the Trust Tasks framework.

Wraps affinidi-tsp so a Trust Task document can ride as the authenticated, encrypted payload of a TSP message — sealed with HPKE authenticated encryption and signed from the producer's Verifiable Identifier (VID) to the recipient's VID. On unwrap, the authenticated sender VID becomes the framework's transport-authenticated sender for SPEC §4.8.1 precedence.

Binding URI

https://trusttasks.org/binding/tsp/0.1

Wire shape

The TSP message payload (the plaintext TSP seals) is the JSON serialisation of the binding envelope object:

{
  "type": "https://trusttasks.org/binding/tsp/0.1/envelope",
  "document": { /* the full TrustTask<P> */ }
}

Unlike the DIDComm binding — which normalises a sender_kid to its bare DID — a TSP VID is the framework VID, so no transformation is applied: the authenticated VID_sndr is surfaced verbatim as the transport-authenticated issuer. TSP has no anonymous/unauthenticated sender mode, so every envelope this binding accepts carries a verified sender.

The producer can ship a plain Direct message ([pack_trust_task], sealed straight to the consumer) or relay it through intermediaries (SPEC binding §5): a Nested envelope sealed to a single intermediary for metadata privacy ([pack_trust_task_nested]), or a Routed envelope relayed through one or more hops ([pack_trust_task_routed]). Routed/Nested relaying — where the messaging mediator unwraps its outer layer and forwards the sealed inner — is the mediator's job on the wire; the consumer always opens the innermost Direct message, which [unpack_trust_task] handles regardless of how it was carried.

Sketch

use affinidi_tsp::PrivateVid;
use trust_tasks_tsp::{pack_trust_task, unpack_trust_task};

// alice (producer) seals a document for bob:
let wire = pack_trust_task(&doc, &alice_private, &bob_resolved)?;

// bob (consumer) opens it (alice's VID resolved for verification):
let (doc, handler) = unpack_trust_task::<MyPayload>(&wire, &bob_private, &alice_resolved)?;