expose more granular data in TaggedHash struct
[rust-lightning] / lightning / src / offers / offer.rs
index d801be9d26fb969c0b89af9b84a5e7408726efea..66dca85cd94c97d6f5b6c594c24d07114d859860 100644 (file)
@@ -13,6 +13,8 @@
 //! published as a QR code to be scanned by a customer. The customer uses the offer to request an
 //! invoice from the merchant to be paid.
 //!
+//! # Example
+//!
 //! ```
 //! extern crate bitcoin;
 //! extern crate core;
 //! # Ok(())
 //! # }
 //! ```
+//!
+//! # Note
+//!
+//! If constructing an [`Offer`] for use with a [`ChannelManager`], use
+//! [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
+//!
+//! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+//! [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
 
 use bitcoin::blockdata::constants::ChainHash;
 use bitcoin::network::constants::Network;
@@ -77,6 +87,7 @@ use core::time::Duration;
 use crate::sign::EntropySource;
 use crate::io;
 use crate::blinded_path::BlindedPath;
+use crate::ln::channelmanager::PaymentId;
 use crate::ln::features::OfferFeatures;
 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
 use crate::ln::msgs::MAX_VALUE_MSAT;
@@ -131,6 +142,14 @@ impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
        /// while the offer is valid.
        ///
        /// Use a different pubkey per offer to avoid correlating offers.
+       ///
+       /// # Note
+       ///
+       /// If constructing an [`Offer`] for use with a [`ChannelManager`], use
+       /// [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
+       ///
+       /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+       /// [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
        pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
                OfferBuilder {
                        offer: OfferContents {
@@ -169,7 +188,7 @@ impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
                secp_ctx: &'a Secp256k1<T>
        ) -> Self where ES::Target: EntropySource {
                let nonce = Nonce::from_entropy_source(entropy_source);
-               let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES);
+               let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
                let metadata = Metadata::DerivedSigningPubkey(derivation_material);
                OfferBuilder {
                        offer: OfferContents {
@@ -190,9 +209,18 @@ impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
        /// See [`Offer::chains`] on how this relates to the payment currency.
        ///
        /// Successive calls to this method will add another chain hash.
-       pub fn chain(mut self, network: Network) -> Self {
+       pub fn chain(self, network: Network) -> Self {
+               self.chain_hash(ChainHash::using_genesis_block(network))
+       }
+
+       /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
+       /// [`Network::Bitcoin`] is assumed to be the only one supported.
+       ///
+       /// See [`Offer::chains`] on how this relates to the payment currency.
+       ///
+       /// Successive calls to this method will add another chain hash.
+       pub(crate) fn chain_hash(mut self, chain: ChainHash) -> Self {
                let chains = self.offer.chains.get_or_insert_with(Vec::new);
-               let chain = ChainHash::using_genesis_block(network);
                if !chains.contains(&chain) {
                        chains.push(chain);
                }
@@ -283,7 +311,7 @@ impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
                                let mut tlv_stream = self.offer.as_tlv_stream();
                                debug_assert_eq!(tlv_stream.metadata, None);
                                tlv_stream.metadata = None;
-                               if metadata.derives_keys() {
+                               if metadata.derives_recipient_keys() {
                                        tlv_stream.node_id = None;
                                }
 
@@ -358,77 +386,91 @@ pub(super) struct OfferContents {
        signing_pubkey: PublicKey,
 }
 
-impl Offer {
+macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
        // TODO: Return a slice once ChainHash has constants.
        // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
        // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
        /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
        /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
        /// for the selected chain.
-       pub fn chains(&self) -> Vec<ChainHash> {
-               self.contents.chains()
-       }
-
-       pub(super) fn implied_chain(&self) -> ChainHash {
-               self.contents.implied_chain()
-       }
-
-       /// Returns whether the given chain is supported by the offer.
-       pub fn supports_chain(&self, chain: ChainHash) -> bool {
-               self.contents.supports_chain(chain)
+       pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
+               $contents.chains()
        }
 
        // TODO: Link to corresponding method in `InvoiceRequest`.
        /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
        /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
-       pub fn metadata(&self) -> Option<&Vec<u8>> {
-               self.contents.metadata()
+       pub fn metadata(&$self) -> Option<&Vec<u8>> {
+               $contents.metadata()
        }
 
        /// The minimum amount required for a successful payment of a single item.
-       pub fn amount(&self) -> Option<&Amount> {
-               self.contents.amount()
+       pub fn amount(&$self) -> Option<&$crate::offers::offer::Amount> {
+               $contents.amount()
        }
 
        /// A complete description of the purpose of the payment. Intended to be displayed to the user
        /// but with the caveat that it has not been verified in any way.
-       pub fn description(&self) -> PrintableString {
-               self.contents.description()
+       pub fn description(&$self) -> $crate::util::string::PrintableString {
+               $contents.description()
        }
 
        /// Features pertaining to the offer.
-       pub fn features(&self) -> &OfferFeatures {
-               &self.contents.features
+       pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
+               &$contents.features()
        }
 
        /// Duration since the Unix epoch when an invoice should no longer be requested.
        ///
        /// If `None`, the offer does not expire.
-       pub fn absolute_expiry(&self) -> Option<Duration> {
-               self.contents.absolute_expiry
-       }
-
-       /// Whether the offer has expired.
-       #[cfg(feature = "std")]
-       pub fn is_expired(&self) -> bool {
-               self.contents.is_expired()
+       pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
+               $contents.absolute_expiry()
        }
 
        /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
        /// displayed to the user but with the caveat that it has not been verified in any way.
-       pub fn issuer(&self) -> Option<PrintableString> {
-               self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
+       pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
+               $contents.issuer()
        }
 
        /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
        /// recipient privacy by obfuscating its node id.
-       pub fn paths(&self) -> &[BlindedPath] {
-               self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
+       pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
+               $contents.paths()
        }
 
        /// The quantity of items supported.
-       pub fn supported_quantity(&self) -> Quantity {
-               self.contents.supported_quantity()
+       pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
+               $contents.supported_quantity()
+       }
+
+       /// The public key used by the recipient to sign invoices.
+       pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
+               $contents.signing_pubkey()
+       }
+} }
+
+impl Offer {
+       offer_accessors!(self, self.contents);
+
+       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)
+       }
+
+       /// Whether the offer has expired.
+       #[cfg(feature = "std")]
+       pub fn is_expired(&self) -> bool {
+               self.contents.is_expired()
+       }
+
+       /// Whether the offer has expired given the duration since the Unix epoch.
+       pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
+               self.contents.is_expired_no_std(duration_since_epoch)
        }
 
        /// Returns whether the given quantity is valid for the offer.
@@ -443,37 +485,37 @@ impl Offer {
                self.contents.expects_quantity()
        }
 
-       /// The public key used by the recipient to sign invoices.
-       pub fn signing_pubkey(&self) -> PublicKey {
-               self.contents.signing_pubkey()
-       }
-
        /// Similar to [`Offer::request_invoice`] except it:
        /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
-       ///   request, and
-       /// - sets the [`InvoiceRequest::metadata`] when [`InvoiceRequestBuilder::build`] is called such
-       ///   that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was requested
-       ///   using a base [`ExpandedKey`] from which the payer id was derived.
+       ///   request,
+       /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
+       ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
+       ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
+       /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
+       ///   be used when sending the payment for the requested invoice.
        ///
        /// Useful to protect the sender's privacy.
        ///
        /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
        ///
        /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
-       /// [`InvoiceRequest::metadata`]: crate::offers::invoice_request::InvoiceRequest::metadata
+       /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
        /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
        /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
        pub fn request_invoice_deriving_payer_id<'a, 'b, ES: Deref, T: secp256k1::Signing>(
-               &'a self, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>
+               &'a self, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>,
+               payment_id: PaymentId
        ) -> Result<InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>, Bolt12SemanticError>
        where
                ES::Target: EntropySource,
        {
-               if self.features().requires_unknown_bits() {
+               if self.offer_features().requires_unknown_bits() {
                        return Err(Bolt12SemanticError::UnknownRequiredFeatures);
                }
 
-               Ok(InvoiceRequestBuilder::deriving_payer_id(self, expanded_key, entropy_source, secp_ctx))
+               Ok(InvoiceRequestBuilder::deriving_payer_id(
+                       self, expanded_key, entropy_source, secp_ctx, payment_id
+               ))
        }
 
        /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
@@ -485,16 +527,19 @@ impl Offer {
        ///
        /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
        pub fn request_invoice_deriving_metadata<ES: Deref>(
-               &self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES
+               &self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
+               payment_id: PaymentId
        ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError>
        where
                ES::Target: EntropySource,
        {
-               if self.features().requires_unknown_bits() {
+               if self.offer_features().requires_unknown_bits() {
                        return Err(Bolt12SemanticError::UnknownRequiredFeatures);
                }
 
-               Ok(InvoiceRequestBuilder::deriving_metadata(self, payer_id, expanded_key, entropy_source))
+               Ok(InvoiceRequestBuilder::deriving_metadata(
+                       self, payer_id, expanded_key, entropy_source, payment_id
+               ))
        }
 
        /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
@@ -515,7 +560,7 @@ impl Offer {
        pub fn request_invoice(
                &self, metadata: Vec<u8>, payer_id: PublicKey
        ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError> {
-               if self.features().requires_unknown_bits() {
+               if self.offer_features().requires_unknown_bits() {
                        return Err(Bolt12SemanticError::UnknownRequiredFeatures);
                }
 
@@ -551,23 +596,42 @@ impl OfferContents {
                self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
        }
 
+       pub fn amount(&self) -> Option<&Amount> {
+               self.amount.as_ref()
+       }
+
        pub fn description(&self) -> PrintableString {
                PrintableString(&self.description)
        }
 
+       pub fn features(&self) -> &OfferFeatures {
+               &self.features
+       }
+
+       pub fn absolute_expiry(&self) -> Option<Duration> {
+               self.absolute_expiry
+       }
+
        #[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,
-               }
+               SystemTime::UNIX_EPOCH
+                       .elapsed()
+                       .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
+                       .unwrap_or(false)
        }
 
-       pub fn amount(&self) -> Option<&Amount> {
-               self.amount.as_ref()
+       pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
+               self.absolute_expiry
+                       .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
+                       .unwrap_or(false)
+       }
+
+       pub fn issuer(&self) -> Option<PrintableString> {
+               self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
+       }
+
+       pub fn paths(&self) -> &[BlindedPath] {
+               self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
        }
 
        pub(super) fn check_amount_msats_for_quantity(
@@ -641,11 +705,13 @@ impl OfferContents {
                                let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
                                        match record.r#type {
                                                OFFER_METADATA_TYPE => false,
-                                               OFFER_NODE_ID_TYPE => !self.metadata.as_ref().unwrap().derives_keys(),
+                                               OFFER_NODE_ID_TYPE => {
+                                                       !self.metadata.as_ref().unwrap().derives_recipient_keys()
+                                               },
                                                _ => true,
                                        }
                                });
-                               signer::verify_metadata(
+                               signer::verify_recipient_metadata(
                                        metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
                                )
                        },
@@ -874,7 +940,7 @@ mod tests {
                assert_eq!(offer.metadata(), None);
                assert_eq!(offer.amount(), None);
                assert_eq!(offer.description(), PrintableString("foo"));
-               assert_eq!(offer.features(), &OfferFeatures::empty());
+               assert_eq!(offer.offer_features(), &OfferFeatures::empty());
                assert_eq!(offer.absolute_expiry(), None);
                #[cfg(feature = "std")]
                assert!(!offer.is_expired());
@@ -1115,7 +1181,7 @@ mod tests {
                        .features_unchecked(OfferFeatures::unknown())
                        .build()
                        .unwrap();
-               assert_eq!(offer.features(), &OfferFeatures::unknown());
+               assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
                assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
 
                let offer = OfferBuilder::new("foo".into(), pubkey(42))
@@ -1123,7 +1189,7 @@ mod tests {
                        .features_unchecked(OfferFeatures::empty())
                        .build()
                        .unwrap();
-               assert_eq!(offer.features(), &OfferFeatures::empty());
+               assert_eq!(offer.offer_features(), &OfferFeatures::empty());
                assert_eq!(offer.as_tlv_stream().features, None);
        }
 
@@ -1131,6 +1197,7 @@ mod tests {
        fn builds_offer_with_absolute_expiry() {
                let future_expiry = Duration::from_secs(u64::max_value());
                let past_expiry = Duration::from_secs(0);
+               let now = future_expiry - Duration::from_secs(1_000);
 
                let offer = OfferBuilder::new("foo".into(), pubkey(42))
                        .absolute_expiry(future_expiry)
@@ -1138,6 +1205,7 @@ mod tests {
                        .unwrap();
                #[cfg(feature = "std")]
                assert!(!offer.is_expired());
+               assert!(!offer.is_expired_no_std(now));
                assert_eq!(offer.absolute_expiry(), Some(future_expiry));
                assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
 
@@ -1148,6 +1216,7 @@ mod tests {
                        .unwrap();
                #[cfg(feature = "std")]
                assert!(offer.is_expired());
+               assert!(offer.is_expired_no_std(now));
                assert_eq!(offer.absolute_expiry(), Some(past_expiry));
                assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
        }