X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Foffers%2Frefund.rs;h=fff33873954a6f92ab55ad2de8d326447dafd0ac;hb=3554678e9c778c8893fc091a6566240a313998f4;hp=4e553cb3e6d47b0aac3aa374c47c238728c67528;hpb=45eb0f3186c277d935b870870e1115a10bcbb599;p=rust-lightning diff --git a/lightning/src/offers/refund.rs b/lightning/src/offers/refund.rs index 4e553cb3..fff33873 100644 --- a/lightning/src/offers/refund.rs +++ b/lightning/src/offers/refund.rs @@ -10,10 +10,11 @@ //! Data structures and encoding for refunds. //! //! A [`Refund`] is an "offer for money" and is typically constructed by a merchant and presented -//! directly to the customer. The recipient responds with an `Invoice` to be paid. +//! directly to the customer. The recipient responds with an [`Invoice`] to be paid. //! //! This is an [`InvoiceRequest`] produced *not* in response to an [`Offer`]. //! +//! [`Invoice`]: crate::offers::invoice::Invoice //! [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest //! [`Offer`]: crate::offers::offer::Offer //! @@ -77,8 +78,10 @@ use core::convert::TryFrom; use core::str::FromStr; use core::time::Duration; use crate::io; +use crate::ln::PaymentHash; use crate::ln::features::InvoiceRequestFeatures; use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT}; +use crate::offers::invoice::{BlindedPayInfo, InvoiceBuilder}; use crate::offers::invoice_request::{InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef}; use crate::offers::offer::{OfferTlvStream, OfferTlvStreamRef}; use crate::offers::parse::{Bech32Encode, ParseError, ParsedMessage, SemanticError}; @@ -102,8 +105,8 @@ pub struct RefundBuilder { } impl RefundBuilder { - /// Creates a new builder for a refund using the [`Refund::payer_id`] for signing invoices. Use - /// a different pubkey per refund to avoid correlating refunds. + /// Creates a new builder for a refund using the [`Refund::payer_id`] for the public node id to + /// send to if no [`Refund::paths`] are set. Otherwise, it may be a transient pubkey. /// /// Additionally, sets the required [`Refund::description`], [`Refund::metadata`], and /// [`Refund::amount_msats`]. @@ -115,9 +118,9 @@ impl RefundBuilder { } let refund = RefundContents { - payer: PayerContents(metadata), metadata: None, description, absolute_expiry: None, - issuer: None, paths: None, chain: None, amount_msats, - features: InvoiceRequestFeatures::empty(), payer_id, payer_note: None, + payer: PayerContents(metadata), description, absolute_expiry: None, issuer: None, + paths: None, chain: None, amount_msats, features: InvoiceRequestFeatures::empty(), + quantity: None, payer_id, payer_note: None, }; Ok(RefundBuilder { refund }) @@ -159,6 +162,20 @@ impl RefundBuilder { self } + /// Sets [`Refund::quantity`] of items. This is purely for informational purposes. It is useful + /// when the refund pertains to an [`Invoice`] that paid for more than one item from an + /// [`Offer`] as specified by [`InvoiceRequest::quantity`]. + /// + /// Successive calls to this method will override the previous setting. + /// + /// [`Invoice`]: crate::offers::invoice::Invoice + /// [`InvoiceRequest::quantity`]: crate::offers::invoice_request::InvoiceRequest::quantity + /// [`Offer`]: crate::offers::offer::Offer + pub fn quantity(mut self, quantity: u64) -> Self { + self.refund.quantity = Some(quantity); + self + } + /// Sets the [`Refund::payer_note`]. /// /// Successive calls to this method will override the previous setting. @@ -191,25 +208,27 @@ impl RefundBuilder { } } -/// A `Refund` is a request to send an `Invoice` without a preceding [`Offer`]. +/// A `Refund` is a request to send an [`Invoice`] without a preceding [`Offer`]. /// /// Typically, after an invoice is paid, the recipient may publish a refund allowing the sender to /// recoup their funds. A refund may be used more generally as an "offer for money", such as with a /// bitcoin ATM. /// +/// [`Invoice`]: crate::offers::invoice::Invoice /// [`Offer`]: crate::offers::offer::Offer #[derive(Clone, Debug)] pub struct Refund { - bytes: Vec, - contents: RefundContents, + pub(super) bytes: Vec, + pub(super) contents: RefundContents, } -/// The contents of a [`Refund`], which may be shared with an `Invoice`. +/// The contents of a [`Refund`], which may be shared with an [`Invoice`]. +/// +/// [`Invoice`]: crate::offers::invoice::Invoice #[derive(Clone, Debug)] -struct RefundContents { +pub(super) struct RefundContents { payer: PayerContents, // offer fields - metadata: Option>, description: String, absolute_expiry: Option, issuer: Option, @@ -218,6 +237,7 @@ struct RefundContents { chain: Option, amount_msats: u64, features: InvoiceRequestFeatures, + quantity: Option, payer_id: PublicKey, payer_note: Option, } @@ -239,13 +259,7 @@ impl Refund { /// Whether the refund has expired. #[cfg(feature = "std")] pub fn is_expired(&self) -> bool { - match self.absolute_expiry() { - Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() { - Ok(elapsed) => elapsed > seconds_from_epoch, - Err(_) => false, - }, - None => false, - } + self.contents.is_expired() } /// The issuer of the refund, possibly beginning with `user@domain` or `domain`. Intended to be @@ -285,7 +299,15 @@ impl Refund { &self.contents.features } - /// A possibly transient pubkey used to sign the refund. + /// The quantity of an item that refund is for. + pub fn quantity(&self) -> Option { + self.contents.quantity + } + + /// A public node id to send to in the case where there are no [`paths`]. Otherwise, a possibly + /// transient pubkey. + /// + /// [`paths`]: Self::paths pub fn payer_id(&self) -> PublicKey { self.contents.payer_id } @@ -295,6 +317,46 @@ impl Refund { self.contents.payer_note.as_ref().map(|payer_note| PrintableString(payer_note.as_str())) } + /// Creates an [`Invoice`] for the refund with the given required fields. + /// + /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after + /// calling this method in `std` builds. For `no-std` builds, a final [`Duration`] parameter + /// must be given, which is used to set [`Invoice::created_at`] since [`std::time::SystemTime`] + /// is not available. + /// + /// The caller is expected to remember the preimage of `payment_hash` in order to + /// claim a payment for the invoice. + /// + /// The `signing_pubkey` is required to sign the invoice since refunds are not in response to an + /// offer, which does have a `signing_pubkey`. + /// + /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It + /// must contain one or more elements ordered from most-preferred to least-preferred, if there's + /// a preference. Note, however, that any privacy is lost if a public node id is used for + /// `signing_pubkey`. + /// + /// Errors if the request contains unknown required features. + /// + /// [`Invoice`]: crate::offers::invoice::Invoice + /// [`Invoice::created_at`]: crate::offers::invoice::Invoice::created_at + pub fn respond_with( + &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash, + signing_pubkey: PublicKey, + #[cfg(any(test, not(feature = "std")))] + created_at: Duration + ) -> Result { + if self.features().requires_unknown_bits() { + return Err(SemanticError::UnknownRequiredFeatures); + } + + #[cfg(all(not(test), feature = "std"))] + let created_at = std::time::SystemTime::now() + .duration_since(std::time::SystemTime::UNIX_EPOCH) + .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH"); + + InvoiceBuilder::for_refund(self, payment_paths, created_at, payment_hash, signing_pubkey) + } + #[cfg(test)] fn as_tlv_stream(&self) -> RefundTlvStreamRef { self.contents.as_tlv_stream() @@ -308,7 +370,18 @@ impl AsRef<[u8]> for Refund { } impl RefundContents { - fn chain(&self) -> ChainHash { + #[cfg(feature = "std")] + pub(super) fn is_expired(&self) -> bool { + match self.absolute_expiry { + Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() { + Ok(elapsed) => elapsed > seconds_from_epoch, + Err(_) => false, + }, + None => false, + } + } + + pub(super) fn chain(&self) -> ChainHash { self.chain.unwrap_or_else(|| self.implied_chain()) } @@ -323,7 +396,7 @@ impl RefundContents { let offer = OfferTlvStreamRef { chains: None, - metadata: self.metadata.as_ref(), + metadata: None, currency: None, amount: None, description: Some(&self.description), @@ -344,7 +417,7 @@ impl RefundContents { chain: self.chain.as_ref(), amount: Some(self.amount_msats), features, - quantity: None, + quantity: self.quantity, payer_id: Some(&self.payer_id), payer_note: self.payer_note.as_ref(), }; @@ -425,6 +498,10 @@ impl TryFrom for RefundContents { Some(metadata) => PayerContents(metadata), }; + if metadata.is_some() { + return Err(SemanticError::UnexpectedMetadata); + } + if chains.is_some() { return Err(SemanticError::UnexpectedChain); } @@ -462,20 +539,14 @@ impl TryFrom for RefundContents { let features = features.unwrap_or_else(InvoiceRequestFeatures::empty); - // TODO: Check why this isn't in the spec. - if quantity.is_some() { - return Err(SemanticError::UnexpectedQuantity); - } - let payer_id = match payer_id { None => return Err(SemanticError::MissingPayerId), Some(payer_id) => payer_id, }; - // TODO: Should metadata be included? Ok(RefundContents { - payer, metadata, description, absolute_expiry, issuer, paths, chain, amount_msats, - features, payer_id, payer_note, + payer, description, absolute_expiry, issuer, paths, chain, amount_msats, features, + quantity, payer_id, payer_note, }) } } @@ -703,6 +774,24 @@ mod tests { assert_eq!(tlv_stream.chain, Some(&testnet)); } + #[test] + fn builds_refund_with_quantity() { + let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap() + .quantity(10) + .build().unwrap(); + let (_, _, tlv_stream) = refund.as_tlv_stream(); + assert_eq!(refund.quantity(), Some(10)); + assert_eq!(tlv_stream.quantity, Some(10)); + + let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap() + .quantity(10) + .quantity(1) + .build().unwrap(); + let (_, _, tlv_stream) = refund.as_tlv_stream(); + assert_eq!(refund.quantity(), Some(1)); + assert_eq!(tlv_stream.quantity, Some(1)); + } + #[test] fn builds_refund_with_payer_note() { let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap() @@ -836,6 +925,7 @@ mod tests { .path(paths[1].clone()) .chain(Network::Testnet) .features_unchecked(InvoiceRequestFeatures::unknown()) + .quantity(10) .payer_note("baz".into()) .build() .unwrap(); @@ -848,6 +938,7 @@ mod tests { assert_eq!(refund.issuer(), Some(PrintableString("bar"))); assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Testnet)); assert_eq!(refund.features(), &InvoiceRequestFeatures::unknown()); + assert_eq!(refund.quantity(), Some(10)); assert_eq!(refund.payer_note(), Some(PrintableString("baz"))); }, Err(e) => panic!("error parsing refund: {:?}", e), @@ -862,6 +953,17 @@ mod tests { panic!("error parsing refund: {:?}", e); } + let metadata = vec![42; 32]; + let mut tlv_stream = refund.as_tlv_stream(); + tlv_stream.1.metadata = Some(&metadata); + + match Refund::try_from(tlv_stream.to_bytes()) { + Ok(_) => panic!("expected error"), + Err(e) => { + assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedMetadata)); + }, + } + let chains = vec![ChainHash::using_genesis_block(Network::Testnet)]; let mut tlv_stream = refund.as_tlv_stream(); tlv_stream.1.chains = Some(&chains); @@ -915,16 +1017,6 @@ mod tests { assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedSigningPubkey)); }, } - - let mut tlv_stream = refund.as_tlv_stream(); - tlv_stream.2.quantity = Some(10); - - match Refund::try_from(tlv_stream.to_bytes()) { - Ok(_) => panic!("expected error"), - Err(e) => { - assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity)); - }, - } } #[test]