Function verify_request

atomic-canonical/src/delegation.rs:408–437

Verify a delegation request's self-signature. The verifying key comes out of the document itself (`delegateKey`), which is exactly what makes this proof of *possession* and nothing more: it shows whoever produced the document holds the private half of the key it names. It carries no authority on its own — the human's countersignature does.

(document: &Value)

/// whoever produced the document holds the private half of the key it names. It
/// carries no authority on its own — the human's countersignature does.
pub fn verify_request(document: &Value) -> Result<DelegationRequest> {
    expect_type(document, TYPE_REQUEST)?;
    let obj = as_object(document)?;

    let delegate_key_did = string_field(obj, "delegateKey")?;
    let public_key = PublicKey::from_did_key(&delegate_key_did)
        .map_err(|e| CanonicalError::Proof(format!("malformed delegateKey: {e}")))?;

    proof::verify_value(document, &public_key)?;

    let delegate = string_field(obj, "delegate")?;
    let delegate_id = IdentityId::from_did(&delegate)
        .map_err(|e| CanonicalError::Verification(format!("delegate DID is malformed: {e}")))?;
    if !delegate_id.matches_public_key(&public_key) {
        return Err(CanonicalError::Verification(
            "delegateKey does not match the delegate DID".into(),
        ));
    }

    Ok(DelegationRequest {
        delegate,
        delegate_key: delegate_key_did,
        delegate_name: string_field(obj, "delegateName")?,
        software_agent: obj
            .get("softwareAgent")
            .and_then(Value::as_str)
            .map(str::to_string),
        requested: timestamp_field(obj, "requested")?,
    })
}

// ---------------------------------------------------------------------------
// Revocation