X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Foffers%2Foffer.rs;h=e655004460024acd7afe2971bc9556392c405a0b;hb=ea1a68c6e6098e8d330792204b05c20d705a372c;hp=6b2dfe2aa5359770f18da167732a013a64857d3c;hpb=94a07d9caee6d38d42954ac783c49afe1cf89697;p=rust-lightning diff --git a/lightning/src/offers/offer.rs b/lightning/src/offers/offer.rs index 6b2dfe2a..e6550044 100644 --- a/lightning/src/offers/offer.rs +++ b/lightning/src/offers/offer.rs @@ -76,6 +76,7 @@ use core::time::Duration; use crate::io; use crate::ln::features::OfferFeatures; use crate::ln::msgs::MAX_VALUE_MSAT; +use crate::offers::invoice_request::InvoiceRequestBuilder; use crate::offers::parse::{Bech32Encode, ParseError, ParsedMessage, SemanticError}; use crate::onion_message::BlindedPath; use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer}; @@ -105,7 +106,7 @@ impl OfferBuilder { let offer = OfferContents { chains: None, metadata: None, amount: None, description, features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None, - supported_quantity: Quantity::one(), signing_pubkey: Some(signing_pubkey), + supported_quantity: Quantity::one(), signing_pubkey, }; OfferBuilder { offer } } @@ -137,27 +138,18 @@ impl OfferBuilder { /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`]. /// /// Successive calls to this method will override the previous setting. - pub fn amount_msats(mut self, amount_msats: u64) -> Self { + pub fn amount_msats(self, amount_msats: u64) -> Self { self.amount(Amount::Bitcoin { amount_msats }) } /// Sets the [`Offer::amount`]. /// /// Successive calls to this method will override the previous setting. - fn amount(mut self, amount: Amount) -> Self { + pub(super) fn amount(mut self, amount: Amount) -> Self { self.offer.amount = Some(amount); self } - /// Sets the [`Offer::features`]. - /// - /// Successive calls to this method will override the previous setting. - #[cfg(test)] - pub fn features(mut self, features: OfferFeatures) -> Self { - self.offer.features = features; - self - } - /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has /// already passed is valid and can be checked for using [`Offer::is_expired`]. /// @@ -185,7 +177,8 @@ impl OfferBuilder { self } - /// Sets the quantity of items for [`Offer::supported_quantity`]. + /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to + /// [`Quantity::one`]. /// /// Successive calls to this method will override the previous setting. pub fn supported_quantity(mut self, quantity: Quantity) -> Self { @@ -221,9 +214,24 @@ impl OfferBuilder { } } +#[cfg(test)] +impl OfferBuilder { + fn features_unchecked(mut self, features: OfferFeatures) -> Self { + self.offer.features = features; + self + } + + pub(super) fn build_unchecked(self) -> Offer { + let mut bytes = Vec::new(); + self.offer.write(&mut bytes).unwrap(); + + Offer { bytes, contents: self.offer } + } +} + /// An `Offer` is a potentially long-lived proposal for payment of a good or service. /// -/// An offer is a precursor to an `InvoiceRequest`. A merchant publishes an offer from which a +/// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a /// customer may request an `Invoice` for a specific quantity and using an amount sufficient to /// cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`]. /// @@ -231,17 +239,21 @@ impl OfferBuilder { /// latter. /// /// Through the use of [`BlindedPath`]s, offers provide recipient privacy. +/// +/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest #[derive(Clone, Debug)] pub struct Offer { // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown // fields. - bytes: Vec, - contents: OfferContents, + pub(super) bytes: Vec, + pub(super) contents: OfferContents, } -/// The contents of an [`Offer`], which may be shared with an `InvoiceRequest` or an `Invoice`. +/// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or an `Invoice`. +/// +/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest #[derive(Clone, Debug)] -pub(crate) struct OfferContents { +pub(super) struct OfferContents { chains: Option>, metadata: Option>, amount: Option, @@ -251,7 +263,7 @@ pub(crate) struct OfferContents { issuer: Option, paths: Option>, supported_quantity: Quantity, - signing_pubkey: Option, + signing_pubkey: PublicKey, } impl Offer { @@ -262,10 +274,16 @@ impl Offer { /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats) /// for the selected chain. pub fn chains(&self) -> Vec { - self.contents.chains - .as_ref() - .cloned() - .unwrap_or_else(|| vec![self.contents.implied_chain()]) + self.contents.chains() + } + + pub(super) fn implied_chain(&self) -> ChainHash { + self.contents.implied_chain() + } + + /// Returns whether the given chain is supported by the offer. + pub fn supports_chain(&self, chain: ChainHash) -> bool { + self.contents.supports_chain(chain) } // TODO: Link to corresponding method in `InvoiceRequest`. @@ -277,7 +295,7 @@ impl Offer { /// The minimum amount required for a successful payment of a single item. pub fn amount(&self) -> Option<&Amount> { - self.contents.amount.as_ref() + self.contents.amount() } /// A complete description of the purpose of the payment. Intended to be displayed to the user @@ -327,13 +345,48 @@ impl Offer { self.contents.supported_quantity() } + /// Returns whether the given quantity is valid for the offer. + pub fn is_valid_quantity(&self, quantity: u64) -> bool { + self.contents.is_valid_quantity(quantity) + } + + /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer. + /// + /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest + pub fn expects_quantity(&self) -> bool { + self.contents.expects_quantity() + } + /// The public key used by the recipient to sign invoices. pub fn signing_pubkey(&self) -> PublicKey { - self.contents.signing_pubkey.unwrap() + self.contents.signing_pubkey + } + + /// Creates an [`InvoiceRequest`] for the offer with the given `metadata` and `payer_id`, which + /// will be reflected in the `Invoice` response. + /// + /// The `metadata` is useful for including information about the derivation of `payer_id` such + /// that invoice response handling can be stateless. Also serves as payer-provided entropy while + /// hashing in the signature calculation. + /// + /// This should not leak any information such as by using a simple BIP-32 derivation path. + /// Otherwise, payments may be correlated. + /// + /// Errors if the offer contains unknown required features. + /// + /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest + pub fn request_invoice( + &self, metadata: Vec, payer_id: PublicKey + ) -> Result { + if self.features().requires_unknown_bits() { + return Err(SemanticError::UnknownRequiredFeatures); + } + + Ok(InvoiceRequestBuilder::new(self, metadata, payer_id)) } #[cfg(test)] - fn as_tlv_stream(&self) -> OfferTlvStreamRef { + pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef { self.contents.as_tlv_stream() } } @@ -345,15 +398,82 @@ impl AsRef<[u8]> for Offer { } impl OfferContents { + pub fn chains(&self) -> Vec { + self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()]) + } + pub fn implied_chain(&self) -> ChainHash { ChainHash::using_genesis_block(Network::Bitcoin) } + pub fn supports_chain(&self, chain: ChainHash) -> bool { + self.chains().contains(&chain) + } + + pub fn amount(&self) -> Option<&Amount> { + self.amount.as_ref() + } + + pub(super) fn check_amount_msats_for_quantity( + &self, amount_msats: Option, quantity: Option + ) -> Result<(), SemanticError> { + let offer_amount_msats = match self.amount { + None => 0, + Some(Amount::Bitcoin { amount_msats }) => amount_msats, + Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency), + }; + + if !self.expects_quantity() || quantity.is_some() { + let expected_amount_msats = offer_amount_msats * quantity.unwrap_or(1); + let amount_msats = amount_msats.unwrap_or(expected_amount_msats); + + if amount_msats < expected_amount_msats { + return Err(SemanticError::InsufficientAmount); + } + + if amount_msats > MAX_VALUE_MSAT { + return Err(SemanticError::InvalidAmount); + } + } + + Ok(()) + } + pub fn supported_quantity(&self) -> Quantity { self.supported_quantity } - fn as_tlv_stream(&self) -> OfferTlvStreamRef { + pub(super) fn check_quantity(&self, quantity: Option) -> Result<(), SemanticError> { + let expects_quantity = self.expects_quantity(); + match quantity { + None if expects_quantity => Err(SemanticError::MissingQuantity), + Some(_) if !expects_quantity => Err(SemanticError::UnexpectedQuantity), + Some(quantity) if !self.is_valid_quantity(quantity) => { + Err(SemanticError::InvalidQuantity) + }, + _ => Ok(()), + } + } + + fn is_valid_quantity(&self, quantity: u64) -> bool { + match self.supported_quantity { + Quantity::Bounded(n) => { + let n = n.get(); + if n == 1 { false } + else { quantity > 0 && quantity <= n } + }, + Quantity::Unbounded => quantity > 0, + } + } + + fn expects_quantity(&self) -> bool { + match self.supported_quantity { + Quantity::Bounded(n) => n.get() != 1, + Quantity::Unbounded => true, + } + } + + pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef { let (currency, amount) = match &self.amount { None => (None, None), Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)), @@ -377,7 +497,7 @@ impl OfferContents { paths: self.paths.as_ref(), issuer: self.issuer.as_ref(), quantity_max: self.supported_quantity.to_tlv_record(), - node_id: self.signing_pubkey.as_ref(), + node_id: Some(&self.signing_pubkey), } } } @@ -425,7 +545,8 @@ pub enum Quantity { } impl Quantity { - fn one() -> Self { + /// The default quantity of one. + pub fn one() -> Self { Quantity::Bounded(NonZeroU64::new(1).unwrap()) } @@ -446,7 +567,7 @@ tlv_stream!(OfferTlvStream, OfferTlvStreamRef, 1..80, { (6, currency: CurrencyCode), (8, amount: (u64, HighZeroBytesDroppedBigSize)), (10, description: (String, WithoutLength)), - (12, features: OfferFeatures), + (12, features: (OfferFeatures, WithoutLength)), (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)), (16, paths: (Vec, WithoutLength)), (18, issuer: (String, WithoutLength)), @@ -513,13 +634,14 @@ impl TryFrom for OfferContents { Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()), }; - if node_id.is_none() { - return Err(SemanticError::MissingSigningPubkey); - } + let signing_pubkey = match node_id { + None => return Err(SemanticError::MissingSigningPubkey), + Some(node_id) => node_id, + }; Ok(OfferContents { chains, metadata, amount, description, features, absolute_expiry, issuer, paths, - supported_quantity, signing_pubkey: node_id, + supported_quantity, signing_pubkey, }) } } @@ -532,7 +654,7 @@ impl core::fmt::Display for Offer { #[cfg(test)] mod tests { - use super::{Amount, Offer, OfferBuilder, Quantity}; + use super::{Amount, Offer, OfferBuilder, OfferTlvStreamRef, Quantity}; use bitcoin::blockdata::constants::ChainHash; use bitcoin::network::constants::Network; @@ -559,12 +681,13 @@ mod tests { #[test] fn builds_offer_with_defaults() { let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap(); - let tlv_stream = offer.as_tlv_stream(); + let mut buffer = Vec::new(); offer.write(&mut buffer).unwrap(); assert_eq!(offer.bytes, buffer.as_slice()); assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]); + assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin))); assert_eq!(offer.metadata(), None); assert_eq!(offer.amount(), None); assert_eq!(offer.description(), PrintableString("foo")); @@ -577,17 +700,22 @@ mod tests { assert_eq!(offer.supported_quantity(), Quantity::one()); assert_eq!(offer.signing_pubkey(), pubkey(42)); - assert_eq!(tlv_stream.chains, None); - assert_eq!(tlv_stream.metadata, None); - assert_eq!(tlv_stream.currency, None); - assert_eq!(tlv_stream.amount, None); - assert_eq!(tlv_stream.description, Some(&String::from("foo"))); - assert_eq!(tlv_stream.features, None); - assert_eq!(tlv_stream.absolute_expiry, None); - assert_eq!(tlv_stream.paths, None); - assert_eq!(tlv_stream.issuer, None); - assert_eq!(tlv_stream.quantity_max, None); - assert_eq!(tlv_stream.node_id, Some(&pubkey(42))); + assert_eq!( + offer.as_tlv_stream(), + OfferTlvStreamRef { + chains: None, + metadata: None, + currency: None, + amount: None, + description: Some(&String::from("foo")), + features: None, + absolute_expiry: None, + paths: None, + issuer: None, + quantity_max: None, + node_id: Some(&pubkey(42)), + }, + ); if let Err(e) = Offer::try_from(buffer) { panic!("error parsing offer: {:?}", e); @@ -603,6 +731,7 @@ mod tests { .chain(Network::Bitcoin) .build() .unwrap(); + assert!(offer.supports_chain(mainnet)); assert_eq!(offer.chains(), vec![mainnet]); assert_eq!(offer.as_tlv_stream().chains, None); @@ -610,6 +739,7 @@ mod tests { .chain(Network::Testnet) .build() .unwrap(); + assert!(offer.supports_chain(testnet)); assert_eq!(offer.chains(), vec![testnet]); assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet])); @@ -618,6 +748,7 @@ mod tests { .chain(Network::Testnet) .build() .unwrap(); + assert!(offer.supports_chain(testnet)); assert_eq!(offer.chains(), vec![testnet]); assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet])); @@ -626,6 +757,8 @@ mod tests { .chain(Network::Testnet) .build() .unwrap(); + assert!(offer.supports_chain(mainnet)); + assert!(offer.supports_chain(testnet)); assert_eq!(offer.chains(), vec![mainnet, testnet]); assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet])); } @@ -692,15 +825,15 @@ mod tests { #[test] fn builds_offer_with_features() { let offer = OfferBuilder::new("foo".into(), pubkey(42)) - .features(OfferFeatures::unknown()) + .features_unchecked(OfferFeatures::unknown()) .build() .unwrap(); assert_eq!(offer.features(), &OfferFeatures::unknown()); assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown())); let offer = OfferBuilder::new("foo".into(), pubkey(42)) - .features(OfferFeatures::unknown()) - .features(OfferFeatures::empty()) + .features_unchecked(OfferFeatures::unknown()) + .features_unchecked(OfferFeatures::empty()) .build() .unwrap(); assert_eq!(offer.features(), &OfferFeatures::empty()); @@ -822,6 +955,18 @@ mod tests { assert_eq!(tlv_stream.quantity_max, None); } + #[test] + fn fails_requesting_invoice_with_unknown_required_features() { + match OfferBuilder::new("foo".into(), pubkey(42)) + .features_unchecked(OfferFeatures::unknown()) + .build().unwrap() + .request_invoice(vec![1; 32], pubkey(43)) + { + Ok(_) => panic!("expected error"), + Err(e) => assert_eq!(e, SemanticError::UnknownRequiredFeatures), + } + } + #[test] fn parses_offer_with_chains() { let offer = OfferBuilder::new("foo".into(), pubkey(42)) @@ -982,11 +1127,13 @@ mod tests { panic!("error parsing offer: {:?}", e); } - let mut builder = OfferBuilder::new("foo".into(), pubkey(42)); - builder.offer.signing_pubkey = None; + let mut tlv_stream = offer.as_tlv_stream(); + tlv_stream.node_id = None; - let offer = builder.build().unwrap(); - match offer.to_string().parse::() { + let mut encoded_offer = Vec::new(); + tlv_stream.write(&mut encoded_offer).unwrap(); + + match Offer::try_from(encoded_offer) { Ok(_) => panic!("expected error"), Err(e) => { assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingSigningPubkey));