Store OffersMessages for later sending
[rust-lightning] / lightning / src / offers / offer.rs
index 1044ac9606d5acbe07e736204a97632c08b6758f..ab95d5b192f6936be0701aefb876089a62054906 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;
                                }
 
@@ -365,7 +393,7 @@ macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
        /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
        /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
        /// for the selected chain.
-       pub fn chains(&$self) -> Vec<$crate::bitcoin::blockdata::constants::ChainHash> {
+       pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
                $contents.chains()
        }
 
@@ -417,7 +445,7 @@ macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
        }
 
        /// The public key used by the recipient to sign invoices.
-       pub fn signing_pubkey(&$self) -> $crate::bitcoin::secp256k1::PublicKey {
+       pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
                $contents.signing_pubkey()
        }
 } }
@@ -454,21 +482,24 @@ impl Offer {
 
        /// 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,
@@ -477,7 +508,9 @@ impl Offer {
                        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
@@ -489,7 +522,8 @@ 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,
@@ -498,7 +532,9 @@ impl Offer {
                        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`,
@@ -661,11 +697,13 @@ 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
                                )
                        },