Enum BindingMode 

pub enum BindingMode {
    DirectWitness,
    DelegatedWitness,
    Unrecognized(String),
}

The attestation-binding mode a receipt was produced under.

Why this is in the payload

-02 required a Verifier to obtain this from a document the Issuer published separately, and simultaneously declined to specify that document. Two problems followed. The obligation could not be discharged, because there was nothing to fetch. And even had there been, a per-receipt fact would have been resolved from a document that describes an Issuer rather than a receipt, so the introduction’s non-extractability property stopped being checkable from the presented bytes.

The mode was fixed at the instant the receipt was signed and was known to the signer. Carrying it costs one string.

Why an unrecognised value is rejected here and preserved in AckProvenance

The two members answer different questions and the difference is not stylistic. adapter.ackProvenance qualifies a record of something that already happened, so refusing to parse it destroys the reconstruction the receipt exists for, and the honest move is to surface the unknown.

attestation.bindingMode selects which security property a reader is entitled to rely on. There is no safe reading of an unrecognised value: it cannot be treated as direct-witness without asserting a property nobody claimed, and treating it as delegated-witness invents a delegation credential to go looking for. So the profile closes the set and this rejects.

Variants

DirectWitness

The signing key is the TEE signing key. Wire value DIRECT_WITNESS.

DelegatedWitness

The signing key is the Issuer’s own, authorised by a TEE-issued delegation credential. Wire value DELEGATED_WITNESS.

A reader of such a receipt obtains a weaker property than the non-extractability one, and the delegation credential is resolved out of band. Nothing in this repository resolves it; see KNOWN-LIMITATIONS.md.

Unrecognized(String)

A value outside the closed set, preserved exactly as it appeared.

Retained rather than dropped so a reader can report what was actually present. A payload carrying this fails validation.

Implementations

impl BindingMode

pub fn as_wire_str(&self) -> &str

Returns the wire string for this value.

pub const fn is_unrecognized(&self) -> bool

Returns true when the value is outside the closed set the profile names.

Trait Implementations

impl Clone for BindingMode

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BindingMode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for BindingMode

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl Eq for BindingMode

impl PartialEq for BindingMode

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for BindingMode

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for BindingMode