Module invoice

Data structures and encoding for invoice messages.

A Bolt12Invoice can be built from a parsed InvoiceRequest for the “offer to be paid” flow or from a Refund as an “offer for money” flow. The expected recipient of the payment then sends the invoice to the intended payer, who will then pay it.

The payment recipient must include a PaymentHash, so as to reveal the preimage upon payment receipt, and one or more BlindedPaths for the payer to use when sending the payment.

extern crate bitcoin;
extern crate lightning;

use bitcoin::hashes::Hash;
use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
use core::convert::{Infallible, TryFrom};
use lightning::offers::invoice_request::InvoiceRequest;
use lightning::offers::refund::Refund;
use lightning::util::ser::Writeable;

let payment_paths = create_payment_paths();
let payment_hash = create_payment_hash();
let secp_ctx = Secp256k1::new();
let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
let pubkey = PublicKey::from(keys);
let wpubkey_hash = bitcoin::util::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
let mut buffer = Vec::new();

// Invoice for the "offer to be paid" flow.
InvoiceRequest::try_from(bytes)?
    .respond_with(payment_paths, payment_hash)?
    .relative_expiry(3600)
    .allow_mpp()
    .fallback_v0_p2wpkh(&wpubkey_hash)
    .build()?
    .sign::<_, Infallible>(
        |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
    )
    .expect("failed verifying signature")
    .write(&mut buffer)
    .unwrap();


// Invoice for the "offer for money" flow.
"lnr1qcp4256ypq"
    .parse::<Refund>()?
    .respond_with(payment_paths, payment_hash, pubkey)?
    .relative_expiry(3600)
    .allow_mpp()
    .fallback_v0_p2wpkh(&wpubkey_hash)
    .build()?
    .sign::<_, Infallible>(
        |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
    )
    .expect("failed verifying signature")
    .write(&mut buffer)
    .unwrap();

Structs

BlindedPayInfo

Information needed to route a payment across a BlindedPath.

Bolt12Invoice

A Bolt12Invoice is a payment request, typically corresponding to an Offer or a Refund.

DerivedSigningPubkey

Bolt12Invoice::signing_pubkey was derived.

ExplicitSigningPubkey

Bolt12Invoice::signing_pubkey was explicitly set.

InvoiceBuilder

Builds a Bolt12Invoice from either:

UnsignedBolt12Invoice

A semantically valid Bolt12Invoice that hasn’t been signed.

Constants

SIGNATURE_TAG

Tag for the hash function used when signing a Bolt12Invoice’s merkle root.

Traits

SigningPubkeyStrategy

Indicates how Bolt12Invoice::signing_pubkey was set.