Generic invoices (BP+LNP+RGB)

Cargo.toml

@@ -43,7 +43,7 @@ bitcoin = { version = "~0.25.1", features = ["rand"] }
 bitcoin_hashes = "~0.9.3" # we need macro from here
 # <https://github.com/LNP-BP/LNPBPs/blob/master/lnpbp-0002.md#deterministic-public-key-extraction-from-bitcoin-script>
 # We have to fix version of miniscript as required by LNPBP-2 specification
-miniscript = { version = "~3.0.0", features = ["compiler"] }
+miniscript = { version = "~4.0.1", features = ["compiler"] }
 bech32 = "~0.7.2"
 lightning-invoice = { version = "~0.3.0", optional = true }
 chacha20poly1305 = "~0.7.0"

src/bp/invoice.rs

@@ -0,0 +1,128 @@
+// LNP/BP Core Library implementing LNPBP specifications & standards
+// Written in 2020 by
+//     Dr. Maxim Orlovsky <orlovsky@pandoracore.com>
+//
+// To the extent possible under law, the author(s) have dedicated all
+// copyright and related and neighboring rights to this software to
+// the public domain worldwide. This software is distributed without
+// any warranty.
+//
+// You should have received a copy of the MIT License
+// along with this software.
+// If not, see <https://opensource.org/licenses/MIT>.
+
+use bitcoin::hashes::sha256d;
+use bitcoin::secp256k1::Signature;
+use bitcoin::Address;
+use miniscript::{descriptor::DescriptorPublicKey, Descriptor, Miniscript};
+use url::Url;
+
+use crate::bp::blind::OutpointHash;
+use crate::bp::chain::AssetId;
+use crate::bp::{Chain, HashLock, P2pNetworkId, Psbt, ScriptPubkeyFormat};
+use crate::lnp::{tlv, Features};
+use crate::secp256k1;
+
+#[derive(Tlv)]
+#[lnpbp_crate(crate)]
+pub enum FieldType {
+    #[tlv(type = 0x01)]
+    Payers,
+}
+
+#[derive(Lnp)]
+#[tlv_types(FieldType)]
+#[lnpbp_crate(crate)]
+pub struct Invoice {
+    network: P2pNetworkId,
+
+    /// List of beneficiary dests ordered in most desirable first order
+    beneficiaries: Vec<Beneficiary>,
+
+    /// Optional list of payers authored to pay
+    #[tlv(type = FieldType::Payers)]
+    payers: Vec<Payer>,
+    quantity: Quantity,
+    price: Option<AmountExt>,
+
+    /// If the price of the asset provided by fiat provider URL goes below this
+    /// limit the merchant will not accept the payment and it will become
+    /// expired
+    fiat_requirement: Option<Fiat>,
+    merchant: Option<String>,
+    asset: Option<AssetId>,
+    purpose: Option<String>,
+    details: Option<Details>,
+    expiry: Option<i64>,
+
+    #[tlv_unknown]
+    unknown: Vec<tlv::Map>,
+    signature: Option<Signature>,
+}
+
+#[non_exhaustive]
+pub enum Beneficiary {
+    /// Addresses are usefult when you do not like to leak public key
+    /// information
+    Address(Address),
+
+    /// Ssed by protocols that work with existing UTXOs and can assign some
+    /// client-validated data to them (like in RGB). We always hide the real
+    /// UTXO behind the hashed version (using some salt)
+    BlindUtxo(OutpointHash),
+
+    /// Miniscript-based descriptors allowing custom derivation & key generation
+    Descriptor(Descriptor<DescriptorPublicKey>),
+
+    /// Full transaction template in PSBT format
+    Psbt(Psbt),
+
+    /// Lightning node receiving the payment. Not the same as lightning invoice
+    /// since many of the invoice data now will be part of [`Invoice`] here.
+    Lightning(LnAddress),
+
+    /// Failback option for all future variants
+    Other(Vec<u8>),
+}
+
+pub struct LnAddress {
+    node_id: secp256k1::PublicKey,
+    features: Features,
+    hash_lock: HashLock,
+    min_final_cltv_expiry: Option<u16>,
+    path_hints: Vec<LnPathHint>,
+}
+
+/// Path hints for a lightning network payment, equal to the value of the `r`
+/// key of the lightning BOLT-11 invoice
+/// <https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md#tagged-fields>
+pub struct LnPathHint {
+    node_id: secp256k1::PublicKey,
+    short_channel_id: ShortChannelId,
+    fee_base_msat: u32,
+    fee_proportional_millionths: u32,
+    cltv_expiry_delta: u16,
+}
+
+pub enum AmountExt {
+    Normal(u64),
+    Milli(u64, u16),
+}
+
+pub struct Details {
+    commitment: sha256d::Hash,
+    source: Url,
+}
+
+pub struct Fiat {
+    iso4217: [u8; 3],
+    coins: u32,
+    fractions: u8,
+    price_provider: Url,
+}
+
+pub struct Quantity {
+    min: Option<u32>,
+    max: Option<u32>,
+    default: u32,
+}

src/bp/mod.rs

@@ -17,6 +17,7 @@ pub mod blind;
 pub mod chain;
 pub mod dbc;
 pub mod hlc;
+mod invoice;
 pub mod lex_order;
 pub mod psbt;
 pub mod resolvers;
@@ -30,6 +31,7 @@ pub mod tagged_hash;
 pub use bip32::{DerivationInfo, DerivationTemplate};
 pub use chain::{Chain, P2pNetworkId};
 pub use hlc::{HashLock, HashPreimage};
+pub use invoice::Invoice;
 pub use lex_order::LexOrder;
 pub use psbt::Psbt;
 pub use scripts::{