Merge pull request #2903 from jkczyz/2024-02-bindings-builders
authorvalentinewallace <valentinewallace@users.noreply.github.com>
Fri, 8 Mar 2024 21:07:10 +0000 (16:07 -0500)
committerGitHub <noreply@github.com>
Fri, 8 Mar 2024 21:07:10 +0000 (16:07 -0500)
Offers builders for C-bindings

fuzz/src/invoice_request_deser.rs
fuzz/src/offer_deser.rs
fuzz/src/refund_deser.rs
lightning/src/crypto/mod.rs
lightning/src/ln/channelmanager.rs
lightning/src/offers/invoice.rs
lightning/src/offers/invoice_request.rs
lightning/src/offers/merkle.rs
lightning/src/offers/offer.rs
lightning/src/offers/refund.rs
lightning/src/offers/test_utils.rs

index 22a2258f4e25f9df7f413bec0b1ab3d07d9a847d..414ce1cdd1cd2c17431d68ea9c1015495b9e074a 100644 (file)
@@ -9,7 +9,7 @@
 
 use bitcoin::secp256k1::{KeyPair, Parity, PublicKey, Secp256k1, SecretKey, self};
 use crate::utils::test_logger;
-use core::convert::{Infallible, TryFrom};
+use core::convert::TryFrom;
 use lightning::blinded_path::BlindedPath;
 use lightning::sign::EntropySource;
 use lightning::ln::PaymentHash;
@@ -37,16 +37,16 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], _out: Out) {
                        let even_pubkey = x_only_pubkey.public_key(Parity::Even);
                        if signing_pubkey == odd_pubkey || signing_pubkey == even_pubkey {
                                unsigned_invoice
-                                       .sign::<_, Infallible>(
-                                               |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+                                       .sign(|message: &UnsignedBolt12Invoice|
+                                               Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
                                        )
                                        .unwrap()
                                        .write(&mut buffer)
                                        .unwrap();
                        } else {
                                unsigned_invoice
-                                       .sign::<_, Infallible>(
-                                               |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+                                       .sign(|message: &UnsignedBolt12Invoice|
+                                               Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
                                        )
                                        .unwrap_err();
                        }
index e16c3b4103b4d568640ce3ff77967d02e5ca6f5b..5aad4642e461f6477a55591cf2239507882cd86a 100644 (file)
@@ -9,7 +9,7 @@
 
 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
 use crate::utils::test_logger;
-use core::convert::{Infallible, TryFrom};
+use core::convert::TryFrom;
 use lightning::offers::invoice_request::UnsignedInvoiceRequest;
 use lightning::offers::offer::{Amount, Offer, Quantity};
 use lightning::offers::parse::Bolt12SemanticError;
@@ -29,8 +29,8 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], _out: Out) {
 
                if let Ok(invoice_request) = build_response(&offer, pubkey) {
                        invoice_request
-                               .sign::<_, Infallible>(
-                                       |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+                               .sign(|message: &UnsignedInvoiceRequest|
+                                       Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
                                )
                                .unwrap()
                                .write(&mut buffer)
index fd273d7e0284573e13899db7e8f510a0da49e0a7..14b136ec35b6d06837c09e997523fc5d093944c1 100644 (file)
@@ -9,7 +9,7 @@
 
 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey, self};
 use crate::utils::test_logger;
-use core::convert::{Infallible, TryFrom};
+use core::convert::TryFrom;
 use lightning::blinded_path::BlindedPath;
 use lightning::sign::EntropySource;
 use lightning::ln::PaymentHash;
@@ -33,8 +33,8 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], _out: Out) {
 
                if let Ok(invoice) = build_response(&refund, pubkey, &secp_ctx) {
                        invoice
-                               .sign::<_, Infallible>(
-                                       |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+                               .sign(|message: &UnsignedBolt12Invoice|
+                                       Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
                                )
                                .unwrap()
                                .write(&mut buffer)
index 6efd120667c2c980e47d53d37bc30691b1946042..b4f5af8f119f01ce908721260094ca22250361a2 100644 (file)
@@ -1,3 +1,4 @@
+#[cfg(not(fuzzing))]
 use bitcoin::hashes::cmp::fixed_time_eq;
 
 pub(crate) mod chacha20;
index 11413db612ab6fa11bbcdad31cf2cad2d57ccb51..8dfd0c8fcaa32538de27b5f255a8b013e3939e26 100644 (file)
@@ -58,10 +58,11 @@ use crate::ln::msgs::{ChannelMessageHandler, DecodeError, LightningError};
 use crate::ln::outbound_payment;
 use crate::ln::outbound_payment::{Bolt12PaymentError, OutboundPayments, PaymentAttempts, PendingOutboundPayment, SendAlongPathArgs, StaleExpiration};
 use crate::ln::wire::Encode;
-use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, InvoiceBuilder};
+use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder, UnsignedBolt12Invoice};
 use crate::offers::invoice_error::InvoiceError;
+use crate::offers::invoice_request::{DerivedPayerId, InvoiceRequestBuilder};
 use crate::offers::merkle::SignError;
-use crate::offers::offer::{DerivedMetadata, Offer, OfferBuilder};
+use crate::offers::offer::{Offer, OfferBuilder};
 use crate::offers::parse::Bolt12SemanticError;
 use crate::offers::refund::{Refund, RefundBuilder};
 use crate::onion_message::messenger::{Destination, MessageRouter, PendingOnionMessage, new_pending_onion_message};
@@ -77,11 +78,17 @@ use crate::util::logger::{Level, Logger, WithContext};
 use crate::util::errors::APIError;
 #[cfg(not(c_bindings))]
 use {
+       crate::offers::offer::DerivedMetadata,
        crate::routing::router::DefaultRouter,
        crate::routing::gossip::NetworkGraph,
        crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters},
        crate::sign::KeysManager,
 };
+#[cfg(c_bindings)]
+use {
+       crate::offers::offer::OfferWithDerivedMetadataBuilder,
+       crate::offers::refund::RefundMaybeWithDerivedMetadataBuilder,
+};
 
 use alloc::collections::{btree_map, BTreeMap};
 
@@ -7633,7 +7640,9 @@ where
                        self.finish_close_channel(failure);
                }
        }
+}
 
+macro_rules! create_offer_builder { ($self: ident, $builder: ty) => {
        /// Creates an [`OfferBuilder`] such that the [`Offer`] it builds is recognized by the
        /// [`ChannelManager`] when handling [`InvoiceRequest`] messages for the offer. The offer will
        /// not have an expiration unless otherwise set on the builder.
@@ -7662,23 +7671,25 @@ where
        /// [`Offer`]: crate::offers::offer::Offer
        /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
        pub fn create_offer_builder(
-               &self, description: String
-       ) -> Result<OfferBuilder<DerivedMetadata, secp256k1::All>, Bolt12SemanticError> {
-               let node_id = self.get_our_node_id();
-               let expanded_key = &self.inbound_payment_key;
-               let entropy = &*self.entropy_source;
-               let secp_ctx = &self.secp_ctx;
-
-               let path = self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
+               &$self, description: String
+       ) -> Result<$builder, Bolt12SemanticError> {
+               let node_id = $self.get_our_node_id();
+               let expanded_key = &$self.inbound_payment_key;
+               let entropy = &*$self.entropy_source;
+               let secp_ctx = &$self.secp_ctx;
+
+               let path = $self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
                let builder = OfferBuilder::deriving_signing_pubkey(
                        description, node_id, expanded_key, entropy, secp_ctx
                )
-                       .chain_hash(self.chain_hash)
+                       .chain_hash($self.chain_hash)
                        .path(path);
 
-               Ok(builder)
+               Ok(builder.into())
        }
+} }
 
+macro_rules! create_refund_builder { ($self: ident, $builder: ty) => {
        /// Creates a [`RefundBuilder`] such that the [`Refund`] it builds is recognized by the
        /// [`ChannelManager`] when handling [`Bolt12Invoice`] messages for the refund.
        ///
@@ -7728,31 +7739,53 @@ where
        /// [`Bolt12Invoice::payment_paths`]: crate::offers::invoice::Bolt12Invoice::payment_paths
        /// [Avoiding Duplicate Payments]: #avoiding-duplicate-payments
        pub fn create_refund_builder(
-               &self, description: String, amount_msats: u64, absolute_expiry: Duration,
+               &$self, description: String, amount_msats: u64, absolute_expiry: Duration,
                payment_id: PaymentId, retry_strategy: Retry, max_total_routing_fee_msat: Option<u64>
-       ) -> Result<RefundBuilder<secp256k1::All>, Bolt12SemanticError> {
-               let node_id = self.get_our_node_id();
-               let expanded_key = &self.inbound_payment_key;
-               let entropy = &*self.entropy_source;
-               let secp_ctx = &self.secp_ctx;
+       ) -> Result<$builder, Bolt12SemanticError> {
+               let node_id = $self.get_our_node_id();
+               let expanded_key = &$self.inbound_payment_key;
+               let entropy = &*$self.entropy_source;
+               let secp_ctx = &$self.secp_ctx;
 
-               let path = self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
+               let path = $self.create_blinded_path().map_err(|_| Bolt12SemanticError::MissingPaths)?;
                let builder = RefundBuilder::deriving_payer_id(
                        description, node_id, expanded_key, entropy, secp_ctx, amount_msats, payment_id
                )?
-                       .chain_hash(self.chain_hash)
+                       .chain_hash($self.chain_hash)
                        .absolute_expiry(absolute_expiry)
                        .path(path);
 
                let expiration = StaleExpiration::AbsoluteTimeout(absolute_expiry);
-               self.pending_outbound_payments
+               $self.pending_outbound_payments
                        .add_new_awaiting_invoice(
                                payment_id, expiration, retry_strategy, max_total_routing_fee_msat,
                        )
                        .map_err(|_| Bolt12SemanticError::DuplicatePaymentId)?;
 
-               Ok(builder)
+               Ok(builder.into())
        }
+} }
+
+impl<M: Deref, T: Deref, ES: Deref, NS: Deref, SP: Deref, F: Deref, R: Deref, L: Deref> ChannelManager<M, T, ES, NS, SP, F, R, L>
+where
+       M::Target: chain::Watch<<SP::Target as SignerProvider>::EcdsaSigner>,
+       T::Target: BroadcasterInterface,
+       ES::Target: EntropySource,
+       NS::Target: NodeSigner,
+       SP::Target: SignerProvider,
+       F::Target: FeeEstimator,
+       R::Target: Router,
+       L::Target: Logger,
+{
+       #[cfg(not(c_bindings))]
+       create_offer_builder!(self, OfferBuilder<DerivedMetadata, secp256k1::All>);
+       #[cfg(not(c_bindings))]
+       create_refund_builder!(self, RefundBuilder<secp256k1::All>);
+
+       #[cfg(c_bindings)]
+       create_offer_builder!(self, OfferWithDerivedMetadataBuilder);
+       #[cfg(c_bindings)]
+       create_refund_builder!(self, RefundMaybeWithDerivedMetadataBuilder);
 
        /// Pays for an [`Offer`] using the given parameters by creating an [`InvoiceRequest`] and
        /// enqueuing it to be sent via an onion message. [`ChannelManager`] will pay the actual
@@ -7816,9 +7849,11 @@ where
                let entropy = &*self.entropy_source;
                let secp_ctx = &self.secp_ctx;
 
-               let builder = offer
+               let builder: InvoiceRequestBuilder<DerivedPayerId, secp256k1::All> = offer
                        .request_invoice_deriving_payer_id(expanded_key, entropy, secp_ctx, payment_id)?
-                       .chain_hash(self.chain_hash)?;
+                       .into();
+               let builder = builder.chain_hash(self.chain_hash)?;
+
                let builder = match quantity {
                        None => builder,
                        Some(quantity) => builder.quantity(quantity)?,
@@ -7912,6 +7947,7 @@ where
                                let builder = refund.respond_using_derived_keys_no_std(
                                        payment_paths, payment_hash, created_at, expanded_key, entropy
                                )?;
+                               let builder: InvoiceBuilder<DerivedSigningPubkey> = builder.into();
                                let invoice = builder.allow_mpp().build_and_sign(secp_ctx)?;
                                let reply_path = self.create_blinded_path()
                                        .map_err(|_| Bolt12SemanticError::MissingPaths)?;
@@ -9424,6 +9460,8 @@ where
                                        let builder = invoice_request.respond_using_derived_keys_no_std(
                                                payment_paths, payment_hash, created_at
                                        );
+                                       let builder: Result<InvoiceBuilder<DerivedSigningPubkey>, _> =
+                                               builder.map(|b| b.into());
                                        match builder.and_then(|b| b.allow_mpp().build_and_sign(secp_ctx)) {
                                                Ok(invoice) => Some(OffersMessage::Invoice(invoice)),
                                                Err(error) => Some(OffersMessage::InvoiceError(error.into())),
@@ -9435,18 +9473,25 @@ where
                                        let builder = invoice_request.respond_with_no_std(
                                                payment_paths, payment_hash, created_at
                                        );
+                                       let builder: Result<InvoiceBuilder<ExplicitSigningPubkey>, _> =
+                                               builder.map(|b| b.into());
                                        let response = builder.and_then(|builder| builder.allow_mpp().build())
                                                .map_err(|e| OffersMessage::InvoiceError(e.into()))
-                                               .and_then(|invoice|
-                                                       match invoice.sign(|invoice| self.node_signer.sign_bolt12_invoice(invoice)) {
+                                               .and_then(|invoice| {
+                                                       #[cfg(c_bindings)]
+                                                       let mut invoice = invoice;
+                                                       match invoice.sign(|invoice: &UnsignedBolt12Invoice|
+                                                               self.node_signer.sign_bolt12_invoice(invoice)
+                                                       ) {
                                                                Ok(invoice) => Ok(OffersMessage::Invoice(invoice)),
-                                                               Err(SignError::Signing(())) => Err(OffersMessage::InvoiceError(
+                                                               Err(SignError::Signing) => Err(OffersMessage::InvoiceError(
                                                                                InvoiceError::from_string("Failed signing invoice".to_string())
                                                                )),
                                                                Err(SignError::Verification(_)) => Err(OffersMessage::InvoiceError(
                                                                                InvoiceError::from_string("Failed invoice signature verification".to_string())
                                                                )),
-                                                       });
+                                                       }
+                                               });
                                        match response {
                                                Ok(invoice) => Some(invoice),
                                                Err(error) => Some(error),
index bb29c76164e1aa7422c5dddda07b8cbd3e7ac01f..fc8371023484d8ade7a2708340a0e2402685d710 100644 (file)
 //!
 //! use bitcoin::hashes::Hash;
 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
-//! use core::convert::{Infallible, TryFrom};
+//! use core::convert::TryFrom;
+//! use lightning::offers::invoice::UnsignedBolt12Invoice;
 //! use lightning::offers::invoice_request::InvoiceRequest;
 //! use lightning::offers::refund::Refund;
 //! use lightning::util::ser::Writeable;
 //!
 //! # use lightning::ln::PaymentHash;
-//! # use lightning::offers::invoice::BlindedPayInfo;
+//! # use lightning::offers::invoice::{BlindedPayInfo, ExplicitSigningPubkey, InvoiceBuilder};
 //! # use lightning::blinded_path::BlindedPath;
 //! #
 //! # fn create_payment_paths() -> Vec<(BlindedPayInfo, BlindedPath)> { unimplemented!() }
@@ -44,6 +45,7 @@
 //! let mut buffer = Vec::new();
 //!
 //! // Invoice for the "offer to be paid" flow.
+//! # <InvoiceBuilder<ExplicitSigningPubkey>>::from(
 //! InvoiceRequest::try_from(bytes)?
 #![cfg_attr(feature = "std", doc = "
     .respond_with(payment_paths, payment_hash)?
 #![cfg_attr(not(feature = "std"), doc = "
     .respond_with_no_std(payment_paths, payment_hash, core::time::Duration::from_secs(0))?
 ")]
+//! # )
 //!     .relative_expiry(3600)
 //!     .allow_mpp()
 //!     .fallback_v0_p2wpkh(&wpubkey_hash)
 //!     .build()?
-//!     .sign::<_, Infallible>(
-//!         |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+//!     .sign(|message: &UnsignedBolt12Invoice|
+//!         Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
 //!     )
 //!     .expect("failed verifying signature")
 //!     .write(&mut buffer)
@@ -74,6 +77,7 @@
 //! # let mut buffer = Vec::new();
 //!
 //! // Invoice for the "offer for money" flow.
+//! # <InvoiceBuilder<ExplicitSigningPubkey>>::from(
 //! "lnr1qcp4256ypq"
 //!     .parse::<Refund>()?
 #![cfg_attr(feature = "std", doc = "
 #![cfg_attr(not(feature = "std"), doc = "
     .respond_with_no_std(payment_paths, payment_hash, pubkey, core::time::Duration::from_secs(0))?
 ")]
+//! # )
 //!     .relative_expiry(3600)
 //!     .allow_mpp()
 //!     .fallback_v0_p2wpkh(&wpubkey_hash)
 //!     .build()?
-//!     .sign::<_, Infallible>(
-//!         |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+//!     .sign(|message: &UnsignedBolt12Invoice|
+//!         Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
 //!     )
 //!     .expect("failed verifying signature")
 //!     .write(&mut buffer)
@@ -105,7 +110,7 @@ use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
 use bitcoin::secp256k1::schnorr::Signature;
 use bitcoin::address::{Address, Payload, WitnessProgram, WitnessVersion};
 use bitcoin::key::TweakedPublicKey;
-use core::convert::{AsRef, Infallible, TryFrom};
+use core::convert::{AsRef, TryFrom};
 use core::time::Duration;
 use crate::io;
 use crate::blinded_path::BlindedPath;
@@ -115,7 +120,7 @@ use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures, InvoiceRequ
 use crate::ln::inbound_payment::ExpandedKey;
 use crate::ln::msgs::DecodeError;
 use crate::offers::invoice_request::{INVOICE_REQUEST_PAYER_ID_TYPE, INVOICE_REQUEST_TYPES, IV_BYTES as INVOICE_REQUEST_IV_BYTES, InvoiceRequest, InvoiceRequestContents, InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
-use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, TlvStream, WithoutSignatures, self};
+use crate::offers::merkle::{SignError, SignFn, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, TlvStream, WithoutSignatures, self};
 use crate::offers::offer::{Amount, OFFER_TYPES, OfferTlvStream, OfferTlvStreamRef, Quantity};
 use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
 use crate::offers::payer::{PAYER_METADATA_TYPE, PayerTlvStream, PayerTlvStreamRef};
@@ -151,6 +156,38 @@ pub struct InvoiceBuilder<'a, S: SigningPubkeyStrategy> {
        signing_pubkey_strategy: S,
 }
 
+/// Builds a [`Bolt12Invoice`] from either:
+/// - an [`InvoiceRequest`] for the "offer to be paid" flow or
+/// - a [`Refund`] for the "offer for money" flow.
+///
+/// See [module-level documentation] for usage.
+///
+/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
+/// [`Refund`]: crate::offers::refund::Refund
+/// [module-level documentation]: self
+#[cfg(c_bindings)]
+pub struct InvoiceWithExplicitSigningPubkeyBuilder<'a> {
+       invreq_bytes: &'a Vec<u8>,
+       invoice: InvoiceContents,
+       signing_pubkey_strategy: ExplicitSigningPubkey,
+}
+
+/// Builds a [`Bolt12Invoice`] from either:
+/// - an [`InvoiceRequest`] for the "offer to be paid" flow or
+/// - a [`Refund`] for the "offer for money" flow.
+///
+/// See [module-level documentation] for usage.
+///
+/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
+/// [`Refund`]: crate::offers::refund::Refund
+/// [module-level documentation]: self
+#[cfg(c_bindings)]
+pub struct InvoiceWithDerivedSigningPubkeyBuilder<'a> {
+       invreq_bytes: &'a Vec<u8>,
+       invoice: InvoiceContents,
+       signing_pubkey_strategy: DerivedSigningPubkey,
+}
+
 /// Indicates how [`Bolt12Invoice::signing_pubkey`] was set.
 ///
 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
@@ -169,7 +206,8 @@ pub struct DerivedSigningPubkey(KeyPair);
 impl SigningPubkeyStrategy for ExplicitSigningPubkey {}
 impl SigningPubkeyStrategy for DerivedSigningPubkey {}
 
-impl<'a> InvoiceBuilder<'a, ExplicitSigningPubkey> {
+macro_rules! invoice_explicit_signing_pubkey_builder_methods { ($self: ident, $self_type: ty) => {
+       #[cfg_attr(c_bindings, allow(dead_code))]
        pub(super) fn for_offer(
                invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>,
                created_at: Duration, payment_hash: PaymentHash
@@ -186,6 +224,7 @@ impl<'a> InvoiceBuilder<'a, ExplicitSigningPubkey> {
                Self::new(&invoice_request.bytes, contents, ExplicitSigningPubkey {})
        }
 
+       #[cfg_attr(c_bindings, allow(dead_code))]
        pub(super) fn for_refund(
                refund: &'a Refund, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, created_at: Duration,
                payment_hash: PaymentHash, signing_pubkey: PublicKey
@@ -200,9 +239,34 @@ impl<'a> InvoiceBuilder<'a, ExplicitSigningPubkey> {
 
                Self::new(&refund.bytes, contents, ExplicitSigningPubkey {})
        }
-}
 
-impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
+       /// Builds an unsigned [`Bolt12Invoice`] after checking for valid semantics. It can be signed by
+       /// [`UnsignedBolt12Invoice::sign`].
+       pub fn build($self: $self_type) -> Result<UnsignedBolt12Invoice, Bolt12SemanticError> {
+               #[cfg(feature = "std")] {
+                       if $self.invoice.is_offer_or_refund_expired() {
+                               return Err(Bolt12SemanticError::AlreadyExpired);
+                       }
+               }
+
+               #[cfg(not(feature = "std"))] {
+                       if $self.invoice.is_offer_or_refund_expired_no_std($self.invoice.created_at()) {
+                               return Err(Bolt12SemanticError::AlreadyExpired);
+                       }
+               }
+
+               let Self { invreq_bytes, invoice, .. } = $self;
+               #[cfg(not(c_bindings))] {
+                       Ok(UnsignedBolt12Invoice::new(invreq_bytes, invoice))
+               }
+               #[cfg(c_bindings)] {
+                       Ok(UnsignedBolt12Invoice::new(invreq_bytes, invoice.clone()))
+               }
+       }
+} }
+
+macro_rules! invoice_derived_signing_pubkey_builder_methods { ($self: ident, $self_type: ty) => {
+       #[cfg_attr(c_bindings, allow(dead_code))]
        pub(super) fn for_offer_using_keys(
                invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>,
                created_at: Duration, payment_hash: PaymentHash, keys: KeyPair
@@ -219,6 +283,7 @@ impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
                Self::new(&invoice_request.bytes, contents, DerivedSigningPubkey(keys))
        }
 
+       #[cfg_attr(c_bindings, allow(dead_code))]
        pub(super) fn for_refund_using_keys(
                refund: &'a Refund, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, created_at: Duration,
                payment_hash: PaymentHash, keys: KeyPair,
@@ -234,9 +299,43 @@ impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
 
                Self::new(&refund.bytes, contents, DerivedSigningPubkey(keys))
        }
-}
 
-impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
+       /// Builds a signed [`Bolt12Invoice`] after checking for valid semantics.
+       pub fn build_and_sign<T: secp256k1::Signing>(
+               $self: $self_type, secp_ctx: &Secp256k1<T>
+       ) -> Result<Bolt12Invoice, Bolt12SemanticError> {
+               #[cfg(feature = "std")] {
+                       if $self.invoice.is_offer_or_refund_expired() {
+                               return Err(Bolt12SemanticError::AlreadyExpired);
+                       }
+               }
+
+               #[cfg(not(feature = "std"))] {
+                       if $self.invoice.is_offer_or_refund_expired_no_std($self.invoice.created_at()) {
+                               return Err(Bolt12SemanticError::AlreadyExpired);
+                       }
+               }
+
+               let Self {
+                       invreq_bytes, invoice, signing_pubkey_strategy: DerivedSigningPubkey(keys)
+               } = $self;
+               #[cfg(not(c_bindings))]
+               let unsigned_invoice = UnsignedBolt12Invoice::new(invreq_bytes, invoice);
+               #[cfg(c_bindings)]
+               let mut unsigned_invoice = UnsignedBolt12Invoice::new(invreq_bytes, invoice.clone());
+
+               let invoice = unsigned_invoice
+                       .sign(|message: &UnsignedBolt12Invoice|
+                               Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+                       )
+                       .unwrap();
+               Ok(invoice)
+       }
+} }
+
+macro_rules! invoice_builder_methods { (
+       $self: ident, $self_type: ty, $return_type: ty, $return_value: expr, $type_param: ty $(, $self_mut: tt)?
+) => {
        pub(crate) fn amount_msats(
                invoice_request: &InvoiceRequest
        ) -> Result<u64, Bolt12SemanticError> {
@@ -253,6 +352,7 @@ impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
                }
        }
 
+       #[cfg_attr(c_bindings, allow(dead_code))]
        fn fields(
                payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, created_at: Duration,
                payment_hash: PaymentHash, amount_msats: u64, signing_pubkey: PublicKey
@@ -263,8 +363,9 @@ impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
                }
        }
 
+       #[cfg_attr(c_bindings, allow(dead_code))]
        fn new(
-               invreq_bytes: &'a Vec<u8>, contents: InvoiceContents, signing_pubkey_strategy: S
+               invreq_bytes: &'a Vec<u8>, contents: InvoiceContents, signing_pubkey_strategy: $type_param
        ) -> Result<Self, Bolt12SemanticError> {
                if contents.fields().payment_paths.is_empty() {
                        return Err(Bolt12SemanticError::MissingPaths);
@@ -278,108 +379,120 @@ impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
        /// [`Bolt12Invoice::is_expired`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn relative_expiry(mut self, relative_expiry_secs: u32) -> Self {
+       pub fn relative_expiry($($self_mut)* $self: $self_type, relative_expiry_secs: u32) -> $return_type {
                let relative_expiry = Duration::from_secs(relative_expiry_secs as u64);
-               self.invoice.fields_mut().relative_expiry = Some(relative_expiry);
-               self
+               $self.invoice.fields_mut().relative_expiry = Some(relative_expiry);
+               $return_value
        }
 
        /// Adds a P2WSH address to [`Bolt12Invoice::fallbacks`].
        ///
        /// Successive calls to this method will add another address. Caller is responsible for not
        /// adding duplicate addresses and only calling if capable of receiving to P2WSH addresses.
-       pub fn fallback_v0_p2wsh(mut self, script_hash: &WScriptHash) -> Self {
+       pub fn fallback_v0_p2wsh($($self_mut)* $self: $self_type, script_hash: &WScriptHash) -> $return_type {
                let address = FallbackAddress {
                        version: WitnessVersion::V0.to_num(),
                        program: Vec::from(script_hash.to_byte_array()),
                };
-               self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
-               self
+               $self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
+               $return_value
        }
 
        /// Adds a P2WPKH address to [`Bolt12Invoice::fallbacks`].
        ///
        /// Successive calls to this method will add another address. Caller is responsible for not
        /// adding duplicate addresses and only calling if capable of receiving to P2WPKH addresses.
-       pub fn fallback_v0_p2wpkh(mut self, pubkey_hash: &WPubkeyHash) -> Self {
+       pub fn fallback_v0_p2wpkh($($self_mut)* $self: $self_type, pubkey_hash: &WPubkeyHash) -> $return_type {
                let address = FallbackAddress {
                        version: WitnessVersion::V0.to_num(),
                        program: Vec::from(pubkey_hash.to_byte_array()),
                };
-               self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
-               self
+               $self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
+               $return_value
        }
 
        /// Adds a P2TR address to [`Bolt12Invoice::fallbacks`].
        ///
        /// Successive calls to this method will add another address. Caller is responsible for not
        /// adding duplicate addresses and only calling if capable of receiving to P2TR addresses.
-       pub fn fallback_v1_p2tr_tweaked(mut self, output_key: &TweakedPublicKey) -> Self {
+       pub fn fallback_v1_p2tr_tweaked($($self_mut)* $self: $self_type, output_key: &TweakedPublicKey) -> $return_type {
                let address = FallbackAddress {
                        version: WitnessVersion::V1.to_num(),
                        program: Vec::from(&output_key.serialize()[..]),
                };
-               self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
-               self
+               $self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
+               $return_value
        }
 
        /// Sets [`Bolt12Invoice::invoice_features`] to indicate MPP may be used. Otherwise, MPP is
        /// disallowed.
-       pub fn allow_mpp(mut self) -> Self {
-               self.invoice.fields_mut().features.set_basic_mpp_optional();
-               self
+       pub fn allow_mpp($($self_mut)* $self: $self_type) -> $return_type {
+               $self.invoice.fields_mut().features.set_basic_mpp_optional();
+               $return_value
        }
-}
+} }
 
 impl<'a> InvoiceBuilder<'a, ExplicitSigningPubkey> {
-       /// Builds an unsigned [`Bolt12Invoice`] after checking for valid semantics. It can be signed by
-       /// [`UnsignedBolt12Invoice::sign`].
-       pub fn build(self) -> Result<UnsignedBolt12Invoice, Bolt12SemanticError> {
-               #[cfg(feature = "std")] {
-                       if self.invoice.is_offer_or_refund_expired() {
-                               return Err(Bolt12SemanticError::AlreadyExpired);
-                       }
-               }
+       invoice_explicit_signing_pubkey_builder_methods!(self, Self);
+}
 
-               #[cfg(not(feature = "std"))] {
-                       if self.invoice.is_offer_or_refund_expired_no_std(self.invoice.created_at()) {
-                               return Err(Bolt12SemanticError::AlreadyExpired);
-                       }
-               }
+impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
+       invoice_derived_signing_pubkey_builder_methods!(self, Self);
+}
 
-               let InvoiceBuilder { invreq_bytes, invoice, .. } = self;
-               Ok(UnsignedBolt12Invoice::new(invreq_bytes, invoice))
-       }
+impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
+       invoice_builder_methods!(self, Self, Self, self, S, mut);
 }
 
-impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
-       /// Builds a signed [`Bolt12Invoice`] after checking for valid semantics.
-       pub fn build_and_sign<T: secp256k1::Signing>(
-               self, secp_ctx: &Secp256k1<T>
-       ) -> Result<Bolt12Invoice, Bolt12SemanticError> {
-               #[cfg(feature = "std")] {
-                       if self.invoice.is_offer_or_refund_expired() {
-                               return Err(Bolt12SemanticError::AlreadyExpired);
-                       }
-               }
+#[cfg(all(c_bindings, not(test)))]
+impl<'a> InvoiceWithExplicitSigningPubkeyBuilder<'a> {
+       invoice_explicit_signing_pubkey_builder_methods!(self, &mut Self);
+       invoice_builder_methods!(self, &mut Self, (), (), ExplicitSigningPubkey);
+}
 
-               #[cfg(not(feature = "std"))] {
-                       if self.invoice.is_offer_or_refund_expired_no_std(self.invoice.created_at()) {
-                               return Err(Bolt12SemanticError::AlreadyExpired);
-                       }
+#[cfg(all(c_bindings, test))]
+impl<'a> InvoiceWithExplicitSigningPubkeyBuilder<'a> {
+       invoice_explicit_signing_pubkey_builder_methods!(self, &mut Self);
+       invoice_builder_methods!(self, &mut Self, &mut Self, self, ExplicitSigningPubkey);
+}
+
+#[cfg(all(c_bindings, not(test)))]
+impl<'a> InvoiceWithDerivedSigningPubkeyBuilder<'a> {
+       invoice_derived_signing_pubkey_builder_methods!(self, &mut Self);
+       invoice_builder_methods!(self, &mut Self, (), (), DerivedSigningPubkey);
+}
+
+#[cfg(all(c_bindings, test))]
+impl<'a> InvoiceWithDerivedSigningPubkeyBuilder<'a> {
+       invoice_derived_signing_pubkey_builder_methods!(self, &mut Self);
+       invoice_builder_methods!(self, &mut Self, &mut Self, self, DerivedSigningPubkey);
+}
+
+#[cfg(c_bindings)]
+impl<'a> From<InvoiceWithExplicitSigningPubkeyBuilder<'a>>
+for InvoiceBuilder<'a, ExplicitSigningPubkey> {
+       fn from(builder: InvoiceWithExplicitSigningPubkeyBuilder<'a>) -> Self {
+               let InvoiceWithExplicitSigningPubkeyBuilder {
+                       invreq_bytes, invoice, signing_pubkey_strategy,
+               } = builder;
+
+               Self {
+                       invreq_bytes, invoice, signing_pubkey_strategy,
                }
+       }
+}
 
-               let InvoiceBuilder {
-                       invreq_bytes, invoice, signing_pubkey_strategy: DerivedSigningPubkey(keys)
-               } = self;
-               let unsigned_invoice = UnsignedBolt12Invoice::new(invreq_bytes, invoice);
+#[cfg(c_bindings)]
+impl<'a> From<InvoiceWithDerivedSigningPubkeyBuilder<'a>>
+for InvoiceBuilder<'a, DerivedSigningPubkey> {
+       fn from(builder: InvoiceWithDerivedSigningPubkeyBuilder<'a>) -> Self {
+               let InvoiceWithDerivedSigningPubkeyBuilder {
+                       invreq_bytes, invoice, signing_pubkey_strategy,
+               } = builder;
 
-               let invoice = unsigned_invoice
-                       .sign::<_, Infallible>(
-                               |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
-                       )
-                       .unwrap();
-               Ok(invoice)
+               Self {
+                       invreq_bytes, invoice, signing_pubkey_strategy,
+               }
        }
 }
 
@@ -395,6 +508,30 @@ pub struct UnsignedBolt12Invoice {
        tagged_hash: TaggedHash,
 }
 
+/// A function for signing an [`UnsignedBolt12Invoice`].
+pub trait SignBolt12InvoiceFn {
+       /// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream.
+       fn sign_invoice(&self, message: &UnsignedBolt12Invoice) -> Result<Signature, ()>;
+}
+
+impl<F> SignBolt12InvoiceFn for F
+where
+       F: Fn(&UnsignedBolt12Invoice) -> Result<Signature, ()>,
+{
+       fn sign_invoice(&self, message: &UnsignedBolt12Invoice) -> Result<Signature, ()> {
+               self(message)
+       }
+}
+
+impl<F> SignFn<UnsignedBolt12Invoice> for F
+where
+       F: SignBolt12InvoiceFn,
+{
+       fn sign(&self, message: &UnsignedBolt12Invoice) -> Result<Signature, ()> {
+               self.sign_invoice(message)
+       }
+}
+
 impl UnsignedBolt12Invoice {
        fn new(invreq_bytes: &[u8], contents: InvoiceContents) -> Self {
                // Use the invoice_request bytes instead of the invoice_request TLV stream as the latter may
@@ -416,32 +553,50 @@ impl UnsignedBolt12Invoice {
        pub fn tagged_hash(&self) -> &TaggedHash {
                &self.tagged_hash
        }
+}
 
+macro_rules! unsigned_invoice_sign_method { ($self: ident, $self_type: ty $(, $self_mut: tt)?) => {
        /// Signs the [`TaggedHash`] of the invoice using the given function.
        ///
        /// Note: The hash computation may have included unknown, odd TLV records.
-       ///
-       /// This is not exported to bindings users as functions aren't currently mapped.
-       pub fn sign<F, E>(mut self, sign: F) -> Result<Bolt12Invoice, SignError<E>>
-       where
-               F: FnOnce(&Self) -> Result<Signature, E>
-       {
-               let pubkey = self.contents.fields().signing_pubkey;
-               let signature = merkle::sign_message(sign, &self, pubkey)?;
+       pub fn sign<F: SignBolt12InvoiceFn>(
+               $($self_mut)* $self: $self_type, sign: F
+       ) -> Result<Bolt12Invoice, SignError> {
+               let pubkey = $self.contents.fields().signing_pubkey;
+               let signature = merkle::sign_message(sign, &$self, pubkey)?;
 
                // Append the signature TLV record to the bytes.
                let signature_tlv_stream = SignatureTlvStreamRef {
                        signature: Some(&signature),
                };
-               signature_tlv_stream.write(&mut self.bytes).unwrap();
+               signature_tlv_stream.write(&mut $self.bytes).unwrap();
 
                Ok(Bolt12Invoice {
-                       bytes: self.bytes,
-                       contents: self.contents,
+                       #[cfg(not(c_bindings))]
+                       bytes: $self.bytes,
+                       #[cfg(c_bindings)]
+                       bytes: $self.bytes.clone(),
+                       #[cfg(not(c_bindings))]
+                       contents: $self.contents,
+                       #[cfg(c_bindings)]
+                       contents: $self.contents.clone(),
                        signature,
-                       tagged_hash: self.tagged_hash,
+                       #[cfg(not(c_bindings))]
+                       tagged_hash: $self.tagged_hash,
+                       #[cfg(c_bindings)]
+                       tagged_hash: $self.tagged_hash.clone(),
                })
        }
+} }
+
+#[cfg(not(c_bindings))]
+impl UnsignedBolt12Invoice {
+       unsigned_invoice_sign_method!(self, Self, mut);
+}
+
+#[cfg(c_bindings)]
+impl UnsignedBolt12Invoice {
+       unsigned_invoice_sign_method!(self, &mut Self);
 }
 
 impl AsRef<TaggedHash> for UnsignedBolt12Invoice {
@@ -1306,10 +1461,19 @@ mod tests {
        use crate::ln::msgs::DecodeError;
        use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
        use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
-       use crate::offers::offer::{Amount, OfferBuilder, OfferTlvStreamRef, Quantity};
+       use crate::offers::offer::{Amount, OfferTlvStreamRef, Quantity};
+       #[cfg(not(c_bindings))]
+       use {
+               crate::offers::offer::OfferBuilder,
+               crate::offers::refund::RefundBuilder,
+       };
+       #[cfg(c_bindings)]
+       use {
+               crate::offers::offer::OfferWithExplicitMetadataBuilder as OfferBuilder,
+               crate::offers::refund::RefundMaybeWithDerivedMetadataBuilder as RefundBuilder,
+       };
        use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
        use crate::offers::payer::PayerTlvStreamRef;
-       use crate::offers::refund::RefundBuilder;
        use crate::offers::test_utils::*;
        use crate::util::ser::{BigSize, Iterable, Writeable};
        use crate::util::string::PrintableString;
@@ -1384,6 +1548,8 @@ mod tests {
                        },
                }
 
+               #[cfg(c_bindings)]
+               let mut unsigned_invoice = unsigned_invoice;
                let invoice = unsigned_invoice.sign(recipient_sign).unwrap();
 
                let mut buffer = Vec::new();
@@ -1644,6 +1810,8 @@ mod tests {
                        ],
                };
 
+               #[cfg(c_bindings)]
+               use crate::offers::offer::OfferWithDerivedMetadataBuilder as OfferBuilder;
                let offer = OfferBuilder
                        ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
                        .amount_msats(1000)
@@ -1867,10 +2035,10 @@ mod tests {
                        .sign(payer_sign).unwrap()
                        .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
                        .build().unwrap()
-                       .sign(|_| Err(()))
+                       .sign(fail_sign)
                {
                        Ok(_) => panic!("expected error"),
-                       Err(e) => assert_eq!(e, SignError::Signing(())),
+                       Err(e) => assert_eq!(e, SignError::Signing),
                }
 
                match OfferBuilder::new("foo".into(), recipient_pubkey())
@@ -2093,11 +2261,18 @@ mod tests {
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
                        .build().unwrap()
                        .sign(payer_sign).unwrap();
+               #[cfg(not(c_bindings))]
+               let invoice_builder = invoice_request
+                       .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap();
+               #[cfg(c_bindings)]
                let mut invoice_builder = invoice_request
-                       .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
+                       .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap();
+               let invoice_builder = invoice_builder
                        .fallback_v0_p2wsh(&script.wscript_hash())
                        .fallback_v0_p2wpkh(&pubkey.wpubkey_hash().unwrap())
                        .fallback_v1_p2tr_tweaked(&tweaked_pubkey);
+               #[cfg(not(c_bindings))]
+               let mut invoice_builder = invoice_builder;
 
                // Only standard addresses will be included.
                let fallbacks = invoice_builder.invoice.fields_mut().fallbacks.as_mut().unwrap();
index 4dd85b352f708de598c60c89e91a3b1896ec81a4..f282075d9333cf1f9002154519474518036b9336 100644 (file)
@@ -25,8 +25,8 @@
 //!
 //! use bitcoin::network::constants::Network;
 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
-//! use core::convert::Infallible;
 //! use lightning::ln::features::OfferFeatures;
+//! use lightning::offers::invoice_request::UnsignedInvoiceRequest;
 //! use lightning::offers::offer::Offer;
 //! use lightning::util::ser::Writeable;
 //!
 //! let pubkey = PublicKey::from(keys);
 //! let mut buffer = Vec::new();
 //!
+//! # use lightning::offers::invoice_request::{ExplicitPayerId, InvoiceRequestBuilder};
+//! # <InvoiceRequestBuilder<ExplicitPayerId, _>>::from(
 //! "lno1qcp4256ypq"
 //!     .parse::<Offer>()?
 //!     .request_invoice(vec![42; 64], pubkey)?
+//! # )
 //!     .chain(Network::Testnet)?
 //!     .amount_msats(1000)?
 //!     .quantity(5)?
 //!     .payer_note("foo".to_string())
 //!     .build()?
-//!     .sign::<_, Infallible>(
-//!         |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+//!     .sign(|message: &UnsignedInvoiceRequest|
+//!         Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
 //!     )
 //!     .expect("failed verifying signature")
 //!     .write(&mut buffer)
@@ -58,7 +61,7 @@ use bitcoin::blockdata::constants::ChainHash;
 use bitcoin::network::constants::Network;
 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
 use bitcoin::secp256k1::schnorr::Signature;
-use core::convert::{AsRef, Infallible, TryFrom};
+use core::convert::{AsRef, TryFrom};
 use core::ops::Deref;
 use crate::sign::EntropySource;
 use crate::io;
@@ -68,8 +71,8 @@ use crate::ln::channelmanager::PaymentId;
 use crate::ln::features::InvoiceRequestFeatures;
 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
 use crate::ln::msgs::DecodeError;
-use crate::offers::invoice::{BlindedPayInfo, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder};
-use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, self};
+use crate::offers::invoice::BlindedPayInfo;
+use crate::offers::merkle::{SignError, SignFn, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, self};
 use crate::offers::offer::{Offer, OfferContents, OfferTlvStream, OfferTlvStreamRef};
 use crate::offers::parse::{Bolt12ParseError, ParsedMessage, Bolt12SemanticError};
 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
@@ -77,6 +80,15 @@ use crate::offers::signer::{Metadata, MetadataMaterial};
 use crate::util::ser::{HighZeroBytesDroppedBigSize, SeekReadable, WithoutLength, Writeable, Writer};
 use crate::util::string::PrintableString;
 
+#[cfg(not(c_bindings))]
+use {
+       crate::offers::invoice::{DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder},
+};
+#[cfg(c_bindings)]
+use {
+       crate::offers::invoice::{InvoiceWithDerivedSigningPubkeyBuilder, InvoiceWithExplicitSigningPubkeyBuilder},
+};
+
 use crate::prelude::*;
 
 /// Tag for the hash function used when signing an [`InvoiceRequest`]'s merkle root.
@@ -99,6 +111,34 @@ pub struct InvoiceRequestBuilder<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signi
        secp_ctx: Option<&'b Secp256k1<T>>,
 }
 
+/// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
+///
+/// See [module-level documentation] for usage.
+///
+/// [module-level documentation]: self
+#[cfg(c_bindings)]
+pub struct InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b> {
+       offer: &'a Offer,
+       invoice_request: InvoiceRequestContentsWithoutPayerId,
+       payer_id: Option<PublicKey>,
+       payer_id_strategy: core::marker::PhantomData<ExplicitPayerId>,
+       secp_ctx: Option<&'b Secp256k1<secp256k1::All>>,
+}
+
+/// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
+///
+/// See [module-level documentation] for usage.
+///
+/// [module-level documentation]: self
+#[cfg(c_bindings)]
+pub struct InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b> {
+       offer: &'a Offer,
+       invoice_request: InvoiceRequestContentsWithoutPayerId,
+       payer_id: Option<PublicKey>,
+       payer_id_strategy: core::marker::PhantomData<DerivedPayerId>,
+       secp_ctx: Option<&'b Secp256k1<secp256k1::All>>,
+}
+
 /// Indicates how [`InvoiceRequest::payer_id`] will be set.
 ///
 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
@@ -117,7 +157,8 @@ pub struct DerivedPayerId {}
 impl PayerIdStrategy for ExplicitPayerId {}
 impl PayerIdStrategy for DerivedPayerId {}
 
-impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
+macro_rules! invoice_request_explicit_payer_id_builder_methods { ($self: ident, $self_type: ty) => {
+       #[cfg_attr(c_bindings, allow(dead_code))]
        pub(super) fn new(offer: &'a Offer, metadata: Vec<u8>, payer_id: PublicKey) -> Self {
                Self {
                        offer,
@@ -128,6 +169,7 @@ impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerI
                }
        }
 
+       #[cfg_attr(c_bindings, allow(dead_code))]
        pub(super) fn deriving_metadata<ES: Deref>(
                offer: &'a Offer, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
                payment_id: PaymentId,
@@ -144,12 +186,23 @@ impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerI
                        secp_ctx: None,
                }
        }
-}
 
-impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
+       /// Builds an unsigned [`InvoiceRequest`] after checking for valid semantics. It can be signed
+       /// by [`UnsignedInvoiceRequest::sign`].
+       pub fn build($self: $self_type) -> Result<UnsignedInvoiceRequest, Bolt12SemanticError> {
+               let (unsigned_invoice_request, keys, _) = $self.build_with_checks()?;
+               debug_assert!(keys.is_none());
+               Ok(unsigned_invoice_request)
+       }
+} }
+
+macro_rules! invoice_request_derived_payer_id_builder_methods { (
+       $self: ident, $self_type: ty, $secp_context: ty
+) => {
+       #[cfg_attr(c_bindings, allow(dead_code))]
        pub(super) fn deriving_payer_id<ES: Deref>(
                offer: &'a Offer, expanded_key: &ExpandedKey, entropy_source: ES,
-               secp_ctx: &'b Secp256k1<T>, payment_id: PaymentId
+               secp_ctx: &'b Secp256k1<$secp_context>, payment_id: PaymentId
        ) -> Self where ES::Target: EntropySource {
                let nonce = Nonce::from_entropy_source(entropy_source);
                let payment_id = Some(payment_id);
@@ -163,9 +216,29 @@ impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId
                        secp_ctx: Some(secp_ctx),
                }
        }
-}
 
-impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
+       /// Builds a signed [`InvoiceRequest`] after checking for valid semantics.
+       pub fn build_and_sign($self: $self_type) -> Result<InvoiceRequest, Bolt12SemanticError> {
+               let (unsigned_invoice_request, keys, secp_ctx) = $self.build_with_checks()?;
+               #[cfg(c_bindings)]
+               let mut unsigned_invoice_request = unsigned_invoice_request;
+               debug_assert!(keys.is_some());
+
+               let secp_ctx = secp_ctx.unwrap();
+               let keys = keys.unwrap();
+               let invoice_request = unsigned_invoice_request
+                       .sign(|message: &UnsignedInvoiceRequest|
+                               Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+                       )
+                       .unwrap();
+               Ok(invoice_request)
+       }
+} }
+
+macro_rules! invoice_request_builder_methods { (
+       $self: ident, $self_type: ty, $return_type: ty, $return_value: expr, $secp_context: ty $(, $self_mut: tt)?
+) => {
+       #[cfg_attr(c_bindings, allow(dead_code))]
        fn create_contents(offer: &Offer, metadata: Metadata) -> InvoiceRequestContentsWithoutPayerId {
                let offer = offer.contents.clone();
                InvoiceRequestContentsWithoutPayerId {
@@ -179,8 +252,8 @@ impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a
        /// by the offer.
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn chain(self, network: Network) -> Result<Self, Bolt12SemanticError> {
-               self.chain_hash(ChainHash::using_genesis_block(network))
+       pub fn chain($self: $self_type, network: Network) -> Result<$return_type, Bolt12SemanticError> {
+               $self.chain_hash(ChainHash::using_genesis_block(network))
        }
 
        /// Sets the [`InvoiceRequest::chain`] for paying an invoice. If not called, the chain hash of
@@ -188,13 +261,13 @@ impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a
        /// offer.
        ///
        /// Successive calls to this method will override the previous setting.
-       pub(crate) fn chain_hash(mut self, chain: ChainHash) -> Result<Self, Bolt12SemanticError> {
-               if !self.offer.supports_chain(chain) {
+       pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> Result<$return_type, Bolt12SemanticError> {
+               if !$self.offer.supports_chain(chain) {
                        return Err(Bolt12SemanticError::UnsupportedChain);
                }
 
-               self.invoice_request.chain = Some(chain);
-               Ok(self)
+               $self.invoice_request.chain = Some(chain);
+               Ok($return_value)
        }
 
        /// Sets the [`InvoiceRequest::amount_msats`] for paying an invoice. Errors if `amount_msats` is
@@ -203,156 +276,208 @@ impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a
        /// Successive calls to this method will override the previous setting.
        ///
        /// [`quantity`]: Self::quantity
-       pub fn amount_msats(mut self, amount_msats: u64) -> Result<Self, Bolt12SemanticError> {
-               self.invoice_request.offer.check_amount_msats_for_quantity(
-                       Some(amount_msats), self.invoice_request.quantity
+       pub fn amount_msats($($self_mut)* $self: $self_type, amount_msats: u64) -> Result<$return_type, Bolt12SemanticError> {
+               $self.invoice_request.offer.check_amount_msats_for_quantity(
+                       Some(amount_msats), $self.invoice_request.quantity
                )?;
-               self.invoice_request.amount_msats = Some(amount_msats);
-               Ok(self)
+               $self.invoice_request.amount_msats = Some(amount_msats);
+               Ok($return_value)
        }
 
        /// Sets [`InvoiceRequest::quantity`] of items. If not set, `1` is assumed. Errors if `quantity`
        /// does not conform to [`Offer::is_valid_quantity`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn quantity(mut self, quantity: u64) -> Result<Self, Bolt12SemanticError> {
-               self.invoice_request.offer.check_quantity(Some(quantity))?;
-               self.invoice_request.quantity = Some(quantity);
-               Ok(self)
+       pub fn quantity($($self_mut)* $self: $self_type, quantity: u64) -> Result<$return_type, Bolt12SemanticError> {
+               $self.invoice_request.offer.check_quantity(Some(quantity))?;
+               $self.invoice_request.quantity = Some(quantity);
+               Ok($return_value)
        }
 
        /// Sets the [`InvoiceRequest::payer_note`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn payer_note(mut self, payer_note: String) -> Self {
-               self.invoice_request.payer_note = Some(payer_note);
-               self
+       pub fn payer_note($($self_mut)* $self: $self_type, payer_note: String) -> $return_type {
+               $self.invoice_request.payer_note = Some(payer_note);
+               $return_value
        }
 
-       fn build_with_checks(mut self) -> Result<
-               (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<T>>),
+       fn build_with_checks($($self_mut)* $self: $self_type) -> Result<
+               (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<$secp_context>>),
                Bolt12SemanticError
        > {
                #[cfg(feature = "std")] {
-                       if self.offer.is_expired() {
+                       if $self.offer.is_expired() {
                                return Err(Bolt12SemanticError::AlreadyExpired);
                        }
                }
 
-               let chain = self.invoice_request.chain();
-               if !self.offer.supports_chain(chain) {
+               let chain = $self.invoice_request.chain();
+               if !$self.offer.supports_chain(chain) {
                        return Err(Bolt12SemanticError::UnsupportedChain);
                }
 
-               if chain == self.offer.implied_chain() {
-                       self.invoice_request.chain = None;
+               if chain == $self.offer.implied_chain() {
+                       $self.invoice_request.chain = None;
                }
 
-               if self.offer.amount().is_none() && self.invoice_request.amount_msats.is_none() {
+               if $self.offer.amount().is_none() && $self.invoice_request.amount_msats.is_none() {
                        return Err(Bolt12SemanticError::MissingAmount);
                }
 
-               self.invoice_request.offer.check_quantity(self.invoice_request.quantity)?;
-               self.invoice_request.offer.check_amount_msats_for_quantity(
-                       self.invoice_request.amount_msats, self.invoice_request.quantity
+               $self.invoice_request.offer.check_quantity($self.invoice_request.quantity)?;
+               $self.invoice_request.offer.check_amount_msats_for_quantity(
+                       $self.invoice_request.amount_msats, $self.invoice_request.quantity
                )?;
 
-               Ok(self.build_without_checks())
+               Ok($self.build_without_checks())
        }
 
-       fn build_without_checks(mut self) ->
-               (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<T>>)
+       fn build_without_checks($($self_mut)* $self: $self_type) ->
+               (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<$secp_context>>)
        {
                // Create the metadata for stateless verification of a Bolt12Invoice.
                let mut keys = None;
-               let secp_ctx = self.secp_ctx.clone();
-               if self.invoice_request.payer.0.has_derivation_material() {
-                       let mut metadata = core::mem::take(&mut self.invoice_request.payer.0);
+               let secp_ctx = $self.secp_ctx.clone();
+               if $self.invoice_request.payer.0.has_derivation_material() {
+                       let mut metadata = core::mem::take(&mut $self.invoice_request.payer.0);
 
-                       let mut tlv_stream = self.invoice_request.as_tlv_stream();
+                       let mut tlv_stream = $self.invoice_request.as_tlv_stream();
                        debug_assert!(tlv_stream.2.payer_id.is_none());
                        tlv_stream.0.metadata = None;
                        if !metadata.derives_payer_keys() {
-                               tlv_stream.2.payer_id = self.payer_id.as_ref();
+                               tlv_stream.2.payer_id = $self.payer_id.as_ref();
                        }
 
-                       let (derived_metadata, derived_keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
+                       let (derived_metadata, derived_keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
                        metadata = derived_metadata;
                        keys = derived_keys;
                        if let Some(keys) = keys {
-                               debug_assert!(self.payer_id.is_none());
-                               self.payer_id = Some(keys.public_key());
+                               debug_assert!($self.payer_id.is_none());
+                               $self.payer_id = Some(keys.public_key());
                        }
 
-                       self.invoice_request.payer.0 = metadata;
+                       $self.invoice_request.payer.0 = metadata;
                }
 
-               debug_assert!(self.invoice_request.payer.0.as_bytes().is_some());
-               debug_assert!(self.payer_id.is_some());
-               let payer_id = self.payer_id.unwrap();
+               debug_assert!($self.invoice_request.payer.0.as_bytes().is_some());
+               debug_assert!($self.payer_id.is_some());
+               let payer_id = $self.payer_id.unwrap();
 
                let invoice_request = InvoiceRequestContents {
-                       inner: self.invoice_request,
+                       #[cfg(not(c_bindings))]
+                       inner: $self.invoice_request,
+                       #[cfg(c_bindings)]
+                       inner: $self.invoice_request.clone(),
                        payer_id,
                };
-               let unsigned_invoice_request = UnsignedInvoiceRequest::new(self.offer, invoice_request);
+               let unsigned_invoice_request = UnsignedInvoiceRequest::new($self.offer, invoice_request);
 
                (unsigned_invoice_request, keys, secp_ctx)
        }
-}
+} }
 
-impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
-       /// Builds an unsigned [`InvoiceRequest`] after checking for valid semantics. It can be signed
-       /// by [`UnsignedInvoiceRequest::sign`].
-       pub fn build(self) -> Result<UnsignedInvoiceRequest, Bolt12SemanticError> {
-               let (unsigned_invoice_request, keys, _) = self.build_with_checks()?;
-               debug_assert!(keys.is_none());
-               Ok(unsigned_invoice_request)
+#[cfg(test)]
+macro_rules! invoice_request_builder_test_methods { (
+       $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
+) => {
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       fn chain_unchecked($($self_mut)* $self: $self_type, network: Network) -> $return_type {
+               let chain = ChainHash::using_genesis_block(network);
+               $self.invoice_request.chain = Some(chain);
+               $return_value
        }
-}
 
-impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
-       /// Builds a signed [`InvoiceRequest`] after checking for valid semantics.
-       pub fn build_and_sign(self) -> Result<InvoiceRequest, Bolt12SemanticError> {
-               let (unsigned_invoice_request, keys, secp_ctx) = self.build_with_checks()?;
-               debug_assert!(keys.is_some());
-
-               let secp_ctx = secp_ctx.unwrap();
-               let keys = keys.unwrap();
-               let invoice_request = unsigned_invoice_request
-                       .sign::<_, Infallible>(
-                               |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
-                       )
-                       .unwrap();
-               Ok(invoice_request)
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       fn amount_msats_unchecked($($self_mut)* $self: $self_type, amount_msats: u64) -> $return_type {
+               $self.invoice_request.amount_msats = Some(amount_msats);
+               $return_value
        }
-}
 
-#[cfg(test)]
-impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
-       fn chain_unchecked(mut self, network: Network) -> Self {
-               let chain = ChainHash::using_genesis_block(network);
-               self.invoice_request.chain = Some(chain);
-               self
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       fn features_unchecked($($self_mut)* $self: $self_type, features: InvoiceRequestFeatures) -> $return_type {
+               $self.invoice_request.features = features;
+               $return_value
        }
 
-       fn amount_msats_unchecked(mut self, amount_msats: u64) -> Self {
-               self.invoice_request.amount_msats = Some(amount_msats);
-               self
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       fn quantity_unchecked($($self_mut)* $self: $self_type, quantity: u64) -> $return_type {
+               $self.invoice_request.quantity = Some(quantity);
+               $return_value
        }
 
-       fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
-               self.invoice_request.features = features;
-               self
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       pub(super) fn build_unchecked($self: $self_type) -> UnsignedInvoiceRequest {
+               $self.build_without_checks().0
        }
+} }
+
+impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
+       invoice_request_explicit_payer_id_builder_methods!(self, Self);
+}
+
+impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
+       invoice_request_derived_payer_id_builder_methods!(self, Self, T);
+}
+
+impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
+       invoice_request_builder_methods!(self, Self, Self, self, T, mut);
+
+       #[cfg(test)]
+       invoice_request_builder_test_methods!(self, Self, Self, self, mut);
+}
+
+#[cfg(all(c_bindings, not(test)))]
+impl<'a, 'b> InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b> {
+       invoice_request_explicit_payer_id_builder_methods!(self, &mut Self);
+       invoice_request_builder_methods!(self, &mut Self, (), (), secp256k1::All);
+}
+
+#[cfg(all(c_bindings, test))]
+impl<'a, 'b> InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b> {
+       invoice_request_explicit_payer_id_builder_methods!(self, &mut Self);
+       invoice_request_builder_methods!(self, &mut Self, &mut Self, self, secp256k1::All);
+       invoice_request_builder_test_methods!(self, &mut Self, &mut Self, self);
+}
+
+#[cfg(all(c_bindings, not(test)))]
+impl<'a, 'b> InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b> {
+       invoice_request_derived_payer_id_builder_methods!(self, &mut Self, secp256k1::All);
+       invoice_request_builder_methods!(self, &mut Self, (), (), secp256k1::All);
+}
+
+#[cfg(all(c_bindings, test))]
+impl<'a, 'b> InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b> {
+       invoice_request_derived_payer_id_builder_methods!(self, &mut Self, secp256k1::All);
+       invoice_request_builder_methods!(self, &mut Self, &mut Self, self, secp256k1::All);
+       invoice_request_builder_test_methods!(self, &mut Self, &mut Self, self);
+}
 
-       fn quantity_unchecked(mut self, quantity: u64) -> Self {
-               self.invoice_request.quantity = Some(quantity);
-               self
+#[cfg(c_bindings)]
+impl<'a, 'b> From<InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b>>
+for InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, secp256k1::All> {
+       fn from(builder: InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b>) -> Self {
+               let InvoiceRequestWithExplicitPayerIdBuilder {
+                       offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
+               } = builder;
+
+               Self {
+                       offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
+               }
        }
+}
+
+#[cfg(c_bindings)]
+impl<'a, 'b> From<InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>>
+for InvoiceRequestBuilder<'a, 'b, DerivedPayerId, secp256k1::All> {
+       fn from(builder: InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>) -> Self {
+               let InvoiceRequestWithDerivedPayerIdBuilder {
+                       offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
+               } = builder;
 
-       pub(super) fn build_unchecked(self) -> UnsignedInvoiceRequest {
-               self.build_without_checks().0
+               Self {
+                       offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
+               }
        }
 }
 
@@ -368,6 +493,30 @@ pub struct UnsignedInvoiceRequest {
        tagged_hash: TaggedHash,
 }
 
+/// A function for signing an [`UnsignedInvoiceRequest`].
+pub trait SignInvoiceRequestFn {
+       /// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream.
+       fn sign_invoice_request(&self, message: &UnsignedInvoiceRequest) -> Result<Signature, ()>;
+}
+
+impl<F> SignInvoiceRequestFn for F
+where
+       F: Fn(&UnsignedInvoiceRequest) -> Result<Signature, ()>,
+{
+       fn sign_invoice_request(&self, message: &UnsignedInvoiceRequest) -> Result<Signature, ()> {
+               self(message)
+       }
+}
+
+impl<F> SignFn<UnsignedInvoiceRequest> for F
+where
+       F: SignInvoiceRequestFn,
+{
+       fn sign(&self, message: &UnsignedInvoiceRequest) -> Result<Signature, ()> {
+               self.sign_invoice_request(message)
+       }
+}
+
 impl UnsignedInvoiceRequest {
        fn new(offer: &Offer, contents: InvoiceRequestContents) -> Self {
                // Use the offer bytes instead of the offer TLV stream as the offer may have contained
@@ -389,31 +538,48 @@ impl UnsignedInvoiceRequest {
        pub fn tagged_hash(&self) -> &TaggedHash {
                &self.tagged_hash
        }
+}
 
+macro_rules! unsigned_invoice_request_sign_method { (
+       $self: ident, $self_type: ty $(, $self_mut: tt)?
+) => {
        /// Signs the [`TaggedHash`] of the invoice request using the given function.
        ///
        /// Note: The hash computation may have included unknown, odd TLV records.
-       ///
-       /// This is not exported to bindings users as functions are not yet mapped.
-       pub fn sign<F, E>(mut self, sign: F) -> Result<InvoiceRequest, SignError<E>>
-       where
-               F: FnOnce(&Self) -> Result<Signature, E>
-       {
-               let pubkey = self.contents.payer_id;
-               let signature = merkle::sign_message(sign, &self, pubkey)?;
+       pub fn sign<F: SignInvoiceRequestFn>(
+               $($self_mut)* $self: $self_type, sign: F
+       ) -> Result<InvoiceRequest, SignError> {
+               let pubkey = $self.contents.payer_id;
+               let signature = merkle::sign_message(sign, &$self, pubkey)?;
 
                // Append the signature TLV record to the bytes.
                let signature_tlv_stream = SignatureTlvStreamRef {
                        signature: Some(&signature),
                };
-               signature_tlv_stream.write(&mut self.bytes).unwrap();
+               signature_tlv_stream.write(&mut $self.bytes).unwrap();
 
                Ok(InvoiceRequest {
-                       bytes: self.bytes,
-                       contents: self.contents,
+                       #[cfg(not(c_bindings))]
+                       bytes: $self.bytes,
+                       #[cfg(c_bindings)]
+                       bytes: $self.bytes.clone(),
+                       #[cfg(not(c_bindings))]
+                       contents: $self.contents,
+                       #[cfg(c_bindings)]
+                       contents: $self.contents.clone(),
                        signature,
                })
        }
+} }
+
+#[cfg(not(c_bindings))]
+impl UnsignedInvoiceRequest {
+       unsigned_invoice_request_sign_method!(self, Self, mut);
+}
+
+#[cfg(c_bindings)]
+impl UnsignedInvoiceRequest {
+       unsigned_invoice_request_sign_method!(self, &mut Self);
 }
 
 impl AsRef<TaggedHash> for UnsignedInvoiceRequest {
@@ -526,35 +692,25 @@ impl UnsignedInvoiceRequest {
        invoice_request_accessors!(self, self.contents);
 }
 
-impl InvoiceRequest {
-       offer_accessors!(self, self.contents.inner.offer);
-       invoice_request_accessors!(self, self.contents);
-
-       /// Signature of the invoice request using [`payer_id`].
-       ///
-       /// [`payer_id`]: Self::payer_id
-       pub fn signature(&self) -> Signature {
-               self.signature
-       }
-
+macro_rules! invoice_request_respond_with_explicit_signing_pubkey_methods { (
+       $self: ident, $contents: expr, $builder: ty
+) => {
        /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
        /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
        ///
        /// See [`InvoiceRequest::respond_with_no_std`] for further details where the aforementioned
        /// creation time is used for the `created_at` parameter.
        ///
-       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
-       ///
        /// [`Duration`]: core::time::Duration
        #[cfg(feature = "std")]
        pub fn respond_with(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
-       ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
+               &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
+       ) -> Result<$builder, Bolt12SemanticError> {
                let created_at = std::time::SystemTime::now()
                        .duration_since(std::time::SystemTime::UNIX_EPOCH)
                        .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 
-               self.respond_with_no_std(payment_paths, payment_hash, created_at)
+               $contents.respond_with_no_std(payment_paths, payment_hash, created_at)
        }
 
        /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
@@ -578,36 +734,72 @@ impl InvoiceRequest {
        /// If the originating [`Offer`] was created using [`OfferBuilder::deriving_signing_pubkey`],
        /// then use [`InvoiceRequest::verify`] and [`VerifiedInvoiceRequest`] methods instead.
        ///
-       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
-       ///
        /// [`Bolt12Invoice::created_at`]: crate::offers::invoice::Bolt12Invoice::created_at
        /// [`OfferBuilder::deriving_signing_pubkey`]: crate::offers::offer::OfferBuilder::deriving_signing_pubkey
        pub fn respond_with_no_std(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
+               &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
                created_at: core::time::Duration
-       ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
-               if self.invoice_request_features().requires_unknown_bits() {
+       ) -> Result<$builder, Bolt12SemanticError> {
+               if $contents.invoice_request_features().requires_unknown_bits() {
                        return Err(Bolt12SemanticError::UnknownRequiredFeatures);
                }
 
-               InvoiceBuilder::for_offer(self, payment_paths, created_at, payment_hash)
+               <$builder>::for_offer(&$contents, payment_paths, created_at, payment_hash)
        }
+} }
 
+macro_rules! invoice_request_verify_method { ($self: ident, $self_type: ty) => {
        /// Verifies that the request was for an offer created using the given key. Returns the verified
        /// request which contains the derived keys needed to sign a [`Bolt12Invoice`] for the request
        /// if they could be extracted from the metadata.
        ///
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
-       pub fn verify<T: secp256k1::Signing>(
-               self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
+       pub fn verify<
+               #[cfg(not(c_bindings))]
+               T: secp256k1::Signing
+       >(
+               $self: $self_type, key: &ExpandedKey,
+               #[cfg(not(c_bindings))]
+               secp_ctx: &Secp256k1<T>,
+               #[cfg(c_bindings)]
+               secp_ctx: &Secp256k1<secp256k1::All>,
        ) -> Result<VerifiedInvoiceRequest, ()> {
-               let keys = self.contents.inner.offer.verify(&self.bytes, key, secp_ctx)?;
+               let keys = $self.contents.inner.offer.verify(&$self.bytes, key, secp_ctx)?;
                Ok(VerifiedInvoiceRequest {
-                       inner: self,
+                       #[cfg(not(c_bindings))]
+                       inner: $self,
+                       #[cfg(c_bindings)]
+                       inner: $self.clone(),
                        keys,
                })
        }
 
+} }
+
+#[cfg(not(c_bindings))]
+impl InvoiceRequest {
+       offer_accessors!(self, self.contents.inner.offer);
+       invoice_request_accessors!(self, self.contents);
+       invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self, InvoiceBuilder<ExplicitSigningPubkey>);
+       invoice_request_verify_method!(self, Self);
+}
+
+#[cfg(c_bindings)]
+impl InvoiceRequest {
+       offer_accessors!(self, self.contents.inner.offer);
+       invoice_request_accessors!(self, self.contents);
+       invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self, InvoiceWithExplicitSigningPubkeyBuilder);
+       invoice_request_verify_method!(self, &Self);
+}
+
+impl InvoiceRequest {
+       /// Signature of the invoice request using [`payer_id`].
+       ///
+       /// [`payer_id`]: Self::payer_id
+       pub fn signature(&self) -> Signature {
+               self.signature
+       }
+
        pub(crate) fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
                let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
                        self.contents.as_tlv_stream();
@@ -618,55 +810,25 @@ impl InvoiceRequest {
        }
 }
 
-impl VerifiedInvoiceRequest {
-       offer_accessors!(self, self.inner.contents.inner.offer);
-       invoice_request_accessors!(self, self.inner.contents);
-
-       /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
-       /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
-       ///
-       /// See [`InvoiceRequest::respond_with_no_std`] for further details.
-       ///
-       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
-       ///
-       /// [`Duration`]: core::time::Duration
-       #[cfg(feature = "std")]
-       pub fn respond_with(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
-       ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
-               self.inner.respond_with(payment_paths, payment_hash)
-       }
-
-       /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
-       ///
-       /// See [`InvoiceRequest::respond_with_no_std`] for further details.
-       ///
-       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
-       pub fn respond_with_no_std(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
-               created_at: core::time::Duration
-       ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
-               self.inner.respond_with_no_std(payment_paths, payment_hash, created_at)
-       }
-
+macro_rules! invoice_request_respond_with_derived_signing_pubkey_methods { (
+       $self: ident, $contents: expr, $builder: ty
+) => {
        /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
        /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
        /// the same [`ExpandedKey`] as the one used to create the offer.
        ///
        /// See [`InvoiceRequest::respond_with`] for further details.
        ///
-       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
-       ///
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        #[cfg(feature = "std")]
        pub fn respond_using_derived_keys(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
-       ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
+               &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
+       ) -> Result<$builder, Bolt12SemanticError> {
                let created_at = std::time::SystemTime::now()
                        .duration_since(std::time::SystemTime::UNIX_EPOCH)
                        .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 
-               self.respond_using_derived_keys_no_std(payment_paths, payment_hash, created_at)
+               $self.respond_using_derived_keys_no_std(payment_paths, payment_hash, created_at)
        }
 
        /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
@@ -675,26 +837,37 @@ impl VerifiedInvoiceRequest {
        ///
        /// See [`InvoiceRequest::respond_with_no_std`] for further details.
        ///
-       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
-       ///
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        pub fn respond_using_derived_keys_no_std(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
+               &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
                created_at: core::time::Duration
-       ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
-               if self.inner.invoice_request_features().requires_unknown_bits() {
+       ) -> Result<$builder, Bolt12SemanticError> {
+               if $self.inner.invoice_request_features().requires_unknown_bits() {
                        return Err(Bolt12SemanticError::UnknownRequiredFeatures);
                }
 
-               let keys = match self.keys {
+               let keys = match $self.keys {
                        None => return Err(Bolt12SemanticError::InvalidMetadata),
                        Some(keys) => keys,
                };
 
-               InvoiceBuilder::for_offer_using_keys(
-                       &self.inner, payment_paths, created_at, payment_hash, keys
+               <$builder>::for_offer_using_keys(
+                       &$self.inner, payment_paths, created_at, payment_hash, keys
                )
        }
+} }
+
+impl VerifiedInvoiceRequest {
+       offer_accessors!(self, self.inner.contents.inner.offer);
+       invoice_request_accessors!(self, self.inner.contents);
+       #[cfg(not(c_bindings))]
+       invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self.inner, InvoiceBuilder<ExplicitSigningPubkey>);
+       #[cfg(c_bindings)]
+       invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self.inner, InvoiceWithExplicitSigningPubkeyBuilder);
+       #[cfg(not(c_bindings))]
+       invoice_request_respond_with_derived_signing_pubkey_methods!(self, self.inner, InvoiceBuilder<DerivedSigningPubkey>);
+       #[cfg(c_bindings)]
+       invoice_request_respond_with_derived_signing_pubkey_methods!(self, self.inner, InvoiceWithDerivedSigningPubkeyBuilder);
 }
 
 impl InvoiceRequestContents {
@@ -930,7 +1103,7 @@ mod tests {
        use bitcoin::blockdata::constants::ChainHash;
        use bitcoin::network::constants::Network;
        use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
-       use core::convert::{Infallible, TryFrom};
+       use core::convert::TryFrom;
        use core::num::NonZeroU64;
        #[cfg(feature = "std")]
        use core::time::Duration;
@@ -941,7 +1114,15 @@ mod tests {
        use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
        use crate::offers::invoice::{Bolt12Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
        use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
-       use crate::offers::offer::{Amount, OfferBuilder, OfferTlvStreamRef, Quantity};
+       use crate::offers::offer::{Amount, OfferTlvStreamRef, Quantity};
+       #[cfg(not(c_bindings))]
+       use {
+               crate::offers::offer::OfferBuilder,
+       };
+       #[cfg(c_bindings)]
+       use {
+               crate::offers::offer::OfferWithExplicitMetadataBuilder as OfferBuilder,
+       };
        use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
        use crate::offers::payer::PayerTlvStreamRef;
        use crate::offers::test_utils::*;
@@ -955,6 +1136,8 @@ mod tests {
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
                        .build().unwrap();
+               #[cfg(c_bindings)]
+               let mut unsigned_invoice_request = unsigned_invoice_request;
 
                let mut buffer = Vec::new();
                unsigned_invoice_request.write(&mut buffer).unwrap();
@@ -1550,10 +1733,10 @@ mod tests {
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
                        .build().unwrap()
-                       .sign(|_| Err(()))
+                       .sign(fail_sign)
                {
                        Ok(_) => panic!("expected error"),
-                       Err(e) => assert_eq!(e, SignError::Signing(())),
+                       Err(e) => assert_eq!(e, SignError::Signing),
                }
 
                match OfferBuilder::new("foo".into(), recipient_pubkey())
@@ -1964,8 +2147,8 @@ mod tests {
                        .build().unwrap()
                        .request_invoice(vec![1; 32], keys.public_key()).unwrap()
                        .build().unwrap()
-                       .sign::<_, Infallible>(
-                               |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
+                       .sign(|message: &UnsignedInvoiceRequest|
+                               Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
                        )
                        .unwrap();
 
index ced3b08b7c2f3a33becd7b2e4f2a444f909a66c9..941bf196716d8b5ee2d2e51d2c4db95716bdf869 100644 (file)
@@ -76,13 +76,28 @@ impl AsRef<TaggedHash> for TaggedHash {
 
 /// Error when signing messages.
 #[derive(Debug, PartialEq)]
-pub enum SignError<E> {
+pub enum SignError {
        /// User-defined error when signing the message.
-       Signing(E),
+       Signing,
        /// Error when verifying the produced signature using the given pubkey.
        Verification(secp256k1::Error),
 }
 
+/// A function for signing a [`TaggedHash`].
+pub(super) trait SignFn<T: AsRef<TaggedHash>> {
+       /// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream.
+       fn sign(&self, message: &T) -> Result<Signature, ()>;
+}
+
+impl<F> SignFn<TaggedHash> for F
+where
+       F: Fn(&TaggedHash) -> Result<Signature, ()>,
+{
+       fn sign(&self, message: &TaggedHash) -> Result<Signature, ()> {
+               self(message)
+       }
+}
+
 /// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream, checking if it
 /// can be verified with the supplied `pubkey`.
 ///
@@ -92,14 +107,14 @@ pub enum SignError<E> {
 ///
 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
-pub(super) fn sign_message<F, E, T>(
-       sign: F, message: &T, pubkey: PublicKey,
-) -> Result<Signature, SignError<E>>
+pub(super) fn sign_message<F, T>(
+       f: F, message: &T, pubkey: PublicKey,
+) -> Result<Signature, SignError>
 where
-       F: FnOnce(&T) -> Result<Signature, E>,
+       F: SignFn<T>,
        T: AsRef<TaggedHash>,
 {
-       let signature = sign(message).map_err(|e| SignError::Signing(e))?;
+       let signature = f.sign(message).map_err(|()| SignError::Signing)?;
 
        let digest = message.as_ref().as_digest();
        let pubkey = pubkey.into();
@@ -276,9 +291,8 @@ mod tests {
        use bitcoin::hashes::hex::FromHex;
        use bitcoin::secp256k1::{KeyPair, Message, Secp256k1, SecretKey};
        use bitcoin::secp256k1::schnorr::Signature;
-       use core::convert::Infallible;
        use crate::offers::offer::{Amount, OfferBuilder};
-       use crate::offers::invoice_request::InvoiceRequest;
+       use crate::offers::invoice_request::{InvoiceRequest, UnsignedInvoiceRequest};
        use crate::offers::parse::Bech32Encode;
        use crate::offers::test_utils::{payer_pubkey, recipient_pubkey};
        use crate::util::ser::Writeable;
@@ -321,8 +335,8 @@ mod tests {
                        .build_unchecked()
                        .request_invoice(vec![0; 8], payer_keys.public_key()).unwrap()
                        .build_unchecked()
-                       .sign::<_, Infallible>(
-                               |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &payer_keys))
+                       .sign(|message: &UnsignedInvoiceRequest|
+                               Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &payer_keys))
                        )
                        .unwrap();
                assert_eq!(
@@ -375,8 +389,8 @@ mod tests {
                        .build_unchecked()
                        .request_invoice(vec![0; 8], payer_keys.public_key()).unwrap()
                        .build_unchecked()
-                       .sign::<_, Infallible>(
-                               |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &payer_keys))
+                       .sign(|message: &UnsignedInvoiceRequest|
+                               Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &payer_keys))
                        )
                        .unwrap();
 
@@ -407,8 +421,8 @@ mod tests {
                        .build_unchecked()
                        .request_invoice(vec![0; 8], payer_keys.public_key()).unwrap()
                        .build_unchecked()
-                       .sign::<_, Infallible>(
-                               |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &payer_keys))
+                       .sign(|message: &UnsignedInvoiceRequest|
+                               Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &payer_keys))
                        )
                        .unwrap();
 
index d71ec2afd04e9642c11d164e4a8c0f6a02e49dda..e9e35836a96e2bec19b5bbe73c390ad78481e4bf 100644 (file)
@@ -92,13 +92,21 @@ 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;
-use crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder};
 use crate::offers::merkle::TlvStream;
 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
 use crate::offers::signer::{Metadata, MetadataMaterial, self};
 use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
 use crate::util::string::PrintableString;
 
+#[cfg(not(c_bindings))]
+use {
+       crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder},
+};
+#[cfg(c_bindings)]
+use {
+       crate::offers::invoice_request::{InvoiceRequestWithDerivedPayerIdBuilder, InvoiceRequestWithExplicitPayerIdBuilder},
+};
+
 use crate::prelude::*;
 
 #[cfg(feature = "std")]
@@ -119,6 +127,34 @@ pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
        secp_ctx: Option<&'a Secp256k1<T>>,
 }
 
+/// Builds an [`Offer`] for the "offer to be paid" flow.
+///
+/// See [module-level documentation] for usage.
+///
+/// This is not exported to bindings users as builder patterns don't map outside of move semantics.
+///
+/// [module-level documentation]: self
+#[cfg(c_bindings)]
+pub struct OfferWithExplicitMetadataBuilder<'a> {
+       offer: OfferContents,
+       metadata_strategy: core::marker::PhantomData<ExplicitMetadata>,
+       secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
+}
+
+/// Builds an [`Offer`] for the "offer to be paid" flow.
+///
+/// See [module-level documentation] for usage.
+///
+/// This is not exported to bindings users as builder patterns don't map outside of move semantics.
+///
+/// [module-level documentation]: self
+#[cfg(c_bindings)]
+pub struct OfferWithDerivedMetadataBuilder<'a> {
+       offer: OfferContents,
+       metadata_strategy: core::marker::PhantomData<DerivedMetadata>,
+       secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
+}
+
 /// Indicates how [`Offer::metadata`] may be set.
 ///
 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
@@ -135,9 +171,12 @@ pub struct ExplicitMetadata {}
 pub struct DerivedMetadata {}
 
 impl MetadataStrategy for ExplicitMetadata {}
+
 impl MetadataStrategy for DerivedMetadata {}
 
-impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
+macro_rules! offer_explicit_metadata_builder_methods { (
+       $self: ident, $self_type: ty, $return_type: ty, $return_value: expr
+) => {
        /// Creates a new builder for an offer setting the [`Offer::description`] and using the
        /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
        /// while the offer is valid.
@@ -152,7 +191,7 @@ impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
        /// [`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 {
+               Self {
                        offer: OfferContents {
                                chains: None, metadata: None, amount: None, description,
                                features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
@@ -166,13 +205,13 @@ impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
        /// Sets the [`Offer::metadata`] to the given bytes.
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn metadata(mut self, metadata: Vec<u8>) -> Result<Self, Bolt12SemanticError> {
-               self.offer.metadata = Some(Metadata::Bytes(metadata));
-               Ok(self)
+       pub fn metadata(mut $self: $self_type, metadata: Vec<u8>) -> Result<$return_type, Bolt12SemanticError> {
+               $self.offer.metadata = Some(Metadata::Bytes(metadata));
+               Ok($return_value)
        }
-}
+} }
 
-impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
+macro_rules! offer_derived_metadata_builder_methods { ($secp_context: ty) => {
        /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
        /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
        /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
@@ -186,12 +225,12 @@ impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
        /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
        pub fn deriving_signing_pubkey<ES: Deref>(
                description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
-               secp_ctx: &'a Secp256k1<T>
+               secp_ctx: &'a Secp256k1<$secp_context>
        ) -> Self where ES::Target: EntropySource {
                let nonce = Nonce::from_entropy_source(entropy_source);
                let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
                let metadata = Metadata::DerivedSigningPubkey(derivation_material);
-               OfferBuilder {
+               Self {
                        offer: OfferContents {
                                chains: None, metadata: Some(metadata), amount: None, description,
                                features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
@@ -201,17 +240,19 @@ impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
                        secp_ctx: Some(secp_ctx),
                }
        }
-}
+} }
 
-impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
+macro_rules! offer_builder_methods { (
+       $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
+) => {
        /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
        /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
        ///
        /// See [`Offer::chains`] on how this relates to the payment currency.
        ///
        /// Successive calls to this method will add another chain hash.
-       pub fn chain(self, network: Network) -> Self {
-               self.chain_hash(ChainHash::using_genesis_block(network))
+       pub fn chain($self: $self_type, network: Network) -> $return_type {
+               $self.chain_hash(ChainHash::using_genesis_block(network))
        }
 
        /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
@@ -220,45 +261,45 @@ 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(crate) fn chain_hash(mut self, chain: ChainHash) -> Self {
-               let chains = self.offer.chains.get_or_insert_with(Vec::new);
+       pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> $return_type {
+               let chains = $self.offer.chains.get_or_insert_with(Vec::new);
                if !chains.contains(&chain) {
                        chains.push(chain);
                }
 
-               self
+               $return_value
        }
 
        /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn amount_msats(self, amount_msats: u64) -> Self {
-               self.amount(Amount::Bitcoin { amount_msats })
+       pub fn amount_msats($self: $self_type, amount_msats: u64) -> $return_type {
+               $self.amount(Amount::Bitcoin { amount_msats })
        }
 
        /// Sets the [`Offer::amount`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub(super) fn amount(mut self, amount: Amount) -> Self {
-               self.offer.amount = Some(amount);
-               self
+       pub(super) fn amount($($self_mut)* $self: $self_type, amount: Amount) -> $return_type {
+               $self.offer.amount = Some(amount);
+               $return_value
        }
 
        /// 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`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
-               self.offer.absolute_expiry = Some(absolute_expiry);
-               self
+       pub fn absolute_expiry($($self_mut)* $self: $self_type, absolute_expiry: Duration) -> $return_type {
+               $self.offer.absolute_expiry = Some(absolute_expiry);
+               $return_value
        }
 
        /// Sets the [`Offer::issuer`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn issuer(mut self, issuer: String) -> Self {
-               self.offer.issuer = Some(issuer);
-               self
+       pub fn issuer($($self_mut)* $self: $self_type, issuer: String) -> $return_type {
+               $self.offer.issuer = Some(issuer);
+               $return_value
        }
 
        /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
@@ -266,23 +307,23 @@ impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
        ///
        /// Successive calls to this method will add another blinded path. Caller is responsible for not
        /// adding duplicate paths.
-       pub fn path(mut self, path: BlindedPath) -> Self {
-               self.offer.paths.get_or_insert_with(Vec::new).push(path);
-               self
+       pub fn path($($self_mut)* $self: $self_type, path: BlindedPath) -> $return_type {
+               $self.offer.paths.get_or_insert_with(Vec::new).push(path);
+               $return_value
        }
 
        /// 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 {
-               self.offer.supported_quantity = quantity;
-               self
+       pub fn supported_quantity($($self_mut)* $self: $self_type, quantity: Quantity) -> $return_type {
+               $self.offer.supported_quantity = quantity;
+               $return_value
        }
 
        /// Builds an [`Offer`] from the builder's settings.
-       pub fn build(mut self) -> Result<Offer, Bolt12SemanticError> {
-               match self.offer.amount {
+       pub fn build($($self_mut)* $self: $self_type) -> Result<Offer, Bolt12SemanticError> {
+               match $self.offer.amount {
                        Some(Amount::Bitcoin { amount_msats }) => {
                                if amount_msats > MAX_VALUE_MSAT {
                                        return Err(Bolt12SemanticError::InvalidAmount);
@@ -292,61 +333,123 @@ impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
                        None => {},
                }
 
-               if let Some(chains) = &self.offer.chains {
-                       if chains.len() == 1 && chains[0] == self.offer.implied_chain() {
-                               self.offer.chains = None;
+               if let Some(chains) = &$self.offer.chains {
+                       if chains.len() == 1 && chains[0] == $self.offer.implied_chain() {
+                               $self.offer.chains = None;
                        }
                }
 
-               Ok(self.build_without_checks())
+               Ok($self.build_without_checks())
        }
 
-       fn build_without_checks(mut self) -> Offer {
+       fn build_without_checks($($self_mut)* $self: $self_type) -> Offer {
                // Create the metadata for stateless verification of an InvoiceRequest.
-               if let Some(mut metadata) = self.offer.metadata.take() {
+               if let Some(mut metadata) = $self.offer.metadata.take() {
                        if metadata.has_derivation_material() {
-                               if self.offer.paths.is_none() {
+                               if $self.offer.paths.is_none() {
                                        metadata = metadata.without_keys();
                                }
 
-                               let mut tlv_stream = self.offer.as_tlv_stream();
+                               let mut tlv_stream = $self.offer.as_tlv_stream();
                                debug_assert_eq!(tlv_stream.metadata, None);
                                tlv_stream.metadata = None;
                                if metadata.derives_recipient_keys() {
                                        tlv_stream.node_id = None;
                                }
 
-                               let (derived_metadata, keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
+                               let (derived_metadata, keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
                                metadata = derived_metadata;
                                if let Some(keys) = keys {
-                                       self.offer.signing_pubkey = keys.public_key();
+                                       $self.offer.signing_pubkey = keys.public_key();
                                }
                        }
 
-                       self.offer.metadata = Some(metadata);
+                       $self.offer.metadata = Some(metadata);
                }
 
                let mut bytes = Vec::new();
-               self.offer.write(&mut bytes).unwrap();
-
-               Offer { bytes, contents: self.offer }
+               $self.offer.write(&mut bytes).unwrap();
+
+               Offer {
+                       bytes,
+                       #[cfg(not(c_bindings))]
+                       contents: $self.offer,
+                       #[cfg(c_bindings)]
+                       contents: $self.offer.clone()
+               }
        }
-}
+} }
 
 #[cfg(test)]
-impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
-       fn features_unchecked(mut self, features: OfferFeatures) -> Self {
-               self.offer.features = features;
-               self
+macro_rules! offer_builder_test_methods { (
+       $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
+) => {
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       fn features_unchecked($($self_mut)* $self: $self_type, features: OfferFeatures) -> $return_type {
+               $self.offer.features = features;
+               $return_value
        }
 
-       pub(crate) fn clear_paths(mut self) -> Self {
-               self.offer.paths = None;
-               self
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       pub(crate) fn clear_paths($($self_mut)* $self: $self_type) -> $return_type {
+               $self.offer.paths = None;
+               $return_value
        }
 
-       pub(super) fn build_unchecked(self) -> Offer {
-               self.build_without_checks()
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       pub(super) fn build_unchecked($self: $self_type) -> Offer {
+               $self.build_without_checks()
+       }
+} }
+
+impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
+       offer_builder_methods!(self, Self, Self, self, mut);
+
+       #[cfg(test)]
+       offer_builder_test_methods!(self, Self, Self, self, mut);
+}
+
+impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
+       offer_explicit_metadata_builder_methods!(self, Self, Self, self);
+}
+
+impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
+       offer_derived_metadata_builder_methods!(T);
+}
+
+#[cfg(all(c_bindings, not(test)))]
+impl<'a> OfferWithExplicitMetadataBuilder<'a> {
+       offer_explicit_metadata_builder_methods!(self, &mut Self, (), ());
+       offer_builder_methods!(self, &mut Self, (), ());
+}
+
+#[cfg(all(c_bindings, test))]
+impl<'a> OfferWithExplicitMetadataBuilder<'a> {
+       offer_explicit_metadata_builder_methods!(self, &mut Self, &mut Self, self);
+       offer_builder_methods!(self, &mut Self, &mut Self, self);
+       offer_builder_test_methods!(self, &mut Self, &mut Self, self);
+}
+
+#[cfg(all(c_bindings, not(test)))]
+impl<'a> OfferWithDerivedMetadataBuilder<'a> {
+       offer_derived_metadata_builder_methods!(secp256k1::All);
+       offer_builder_methods!(self, &mut Self, (), ());
+}
+
+#[cfg(all(c_bindings, test))]
+impl<'a> OfferWithDerivedMetadataBuilder<'a> {
+       offer_derived_metadata_builder_methods!(secp256k1::All);
+       offer_builder_methods!(self, &mut Self, &mut Self, self);
+       offer_builder_test_methods!(self, &mut Self, &mut Self, self);
+}
+
+#[cfg(c_bindings)]
+impl<'a> From<OfferBuilder<'a, DerivedMetadata, secp256k1::All>>
+for OfferWithDerivedMetadataBuilder<'a> {
+       fn from(builder: OfferBuilder<'a, DerivedMetadata, secp256k1::All>) -> Self {
+               let OfferBuilder { offer, metadata_strategy, secp_ctx } = builder;
+
+               Self { offer, metadata_strategy, secp_ctx }
        }
 }
 
@@ -489,7 +592,9 @@ impl Offer {
        pub fn expects_quantity(&self) -> bool {
                self.contents.expects_quantity()
        }
+}
 
+macro_rules! request_invoice_derived_payer_id { ($self: ident, $builder: ty) => {
        /// Similar to [`Offer::request_invoice`] except it:
        /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
        ///   request,
@@ -501,50 +606,52 @@ impl Offer {
        ///
        /// 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::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>,
+       pub fn request_invoice_deriving_payer_id<
+               'a, 'b, ES: Deref,
+               #[cfg(not(c_bindings))]
+               T: secp256k1::Signing
+       >(
+               &'a $self, expanded_key: &ExpandedKey, entropy_source: ES,
+               #[cfg(not(c_bindings))]
+               secp_ctx: &'b Secp256k1<T>,
+               #[cfg(c_bindings)]
+               secp_ctx: &'b Secp256k1<secp256k1::All>,
                payment_id: PaymentId
-       ) -> Result<InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>, Bolt12SemanticError>
+       ) -> Result<$builder, Bolt12SemanticError>
        where
                ES::Target: EntropySource,
        {
-               if self.offer_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, payment_id
-               ))
+               Ok(<$builder>::deriving_payer_id($self, expanded_key, entropy_source, secp_ctx, payment_id))
        }
+} }
 
+macro_rules! request_invoice_explicit_payer_id { ($self: ident, $builder: ty) => {
        /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
        /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
        ///
        /// Useful for recurring payments using the same `payer_id` with different invoices.
        ///
-       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
-       ///
        /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
        pub fn request_invoice_deriving_metadata<ES: Deref>(
-               &self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
+               &$self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
                payment_id: PaymentId
-       ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError>
+       ) -> Result<$builder, Bolt12SemanticError>
        where
                ES::Target: EntropySource,
        {
-               if self.offer_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, payment_id
-               ))
+               Ok(<$builder>::deriving_metadata($self, payer_id, expanded_key, entropy_source, payment_id))
        }
 
        /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
@@ -559,20 +666,32 @@ impl Offer {
        ///
        /// Errors if the offer contains unknown required features.
        ///
-       /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
-       ///
        /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
        pub fn request_invoice(
-               &self, metadata: Vec<u8>, payer_id: PublicKey
-       ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError> {
-               if self.offer_features().requires_unknown_bits() {
+               &$self, metadata: Vec<u8>, payer_id: PublicKey
+       ) -> Result<$builder, Bolt12SemanticError> {
+               if $self.offer_features().requires_unknown_bits() {
                        return Err(Bolt12SemanticError::UnknownRequiredFeatures);
                }
 
-               Ok(InvoiceRequestBuilder::new(self, metadata, payer_id))
+               Ok(<$builder>::new($self, metadata, payer_id))
        }
+} }
 
-       #[cfg(test)]
+#[cfg(not(c_bindings))]
+impl Offer {
+       request_invoice_derived_payer_id!(self, InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>);
+       request_invoice_explicit_payer_id!(self, InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>);
+}
+
+#[cfg(c_bindings)]
+impl Offer {
+       request_invoice_derived_payer_id!(self, InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>);
+       request_invoice_explicit_payer_id!(self, InvoiceRequestWithExplicitPayerIdBuilder);
+}
+
+#[cfg(test)]
+impl Offer {
        pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
                self.contents.as_tlv_stream()
        }
@@ -928,7 +1047,15 @@ impl core::fmt::Display for Offer {
 
 #[cfg(test)]
 mod tests {
-       use super::{Amount, Offer, OfferBuilder, OfferTlvStreamRef, Quantity};
+       use super::{Amount, Offer, OfferTlvStreamRef, Quantity};
+       #[cfg(not(c_bindings))]
+       use {
+               super::OfferBuilder,
+       };
+       #[cfg(c_bindings)]
+       use {
+               super::OfferWithExplicitMetadataBuilder as OfferBuilder,
+       };
 
        use bitcoin::blockdata::constants::ChainHash;
        use bitcoin::network::constants::Network;
@@ -1057,6 +1184,8 @@ mod tests {
                let entropy = FixedEntropy {};
                let secp_ctx = Secp256k1::new();
 
+               #[cfg(c_bindings)]
+               use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
                let offer = OfferBuilder
                        ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
                        .amount_msats(1000)
@@ -1113,6 +1242,8 @@ mod tests {
                        ],
                };
 
+               #[cfg(c_bindings)]
+               use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
                let offer = OfferBuilder
                        ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
                        .amount_msats(1000)
@@ -1167,8 +1298,13 @@ mod tests {
                assert_eq!(tlv_stream.amount, Some(1000));
                assert_eq!(tlv_stream.currency, None);
 
+               #[cfg(not(c_bindings))]
                let builder = OfferBuilder::new("foo".into(), pubkey(42))
                        .amount(currency_amount.clone());
+               #[cfg(c_bindings)]
+               let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
+               #[cfg(c_bindings)]
+               builder.amount(currency_amount.clone());
                let tlv_stream = builder.offer.as_tlv_stream();
                assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
                assert_eq!(tlv_stream.amount, Some(10));
index 5107e31d8d0a07e6527d7838d7a19439c86e54c1..42177960868ab553ee1385f2569146dc8209e2bf 100644 (file)
@@ -97,7 +97,7 @@ use crate::ln::channelmanager::PaymentId;
 use crate::ln::features::InvoiceRequestFeatures;
 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
-use crate::offers::invoice::{BlindedPayInfo, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder};
+use crate::offers::invoice::BlindedPayInfo;
 use crate::offers::invoice_request::{InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
 use crate::offers::offer::{OfferTlvStream, OfferTlvStreamRef};
 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
@@ -106,6 +106,15 @@ use crate::offers::signer::{Metadata, MetadataMaterial, self};
 use crate::util::ser::{SeekReadable, WithoutLength, Writeable, Writer};
 use crate::util::string::PrintableString;
 
+#[cfg(not(c_bindings))]
+use {
+       crate::offers::invoice::{DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder},
+};
+#[cfg(c_bindings)]
+use {
+       crate::offers::invoice::{InvoiceWithDerivedSigningPubkeyBuilder, InvoiceWithExplicitSigningPubkeyBuilder},
+};
+
 use crate::prelude::*;
 
 #[cfg(feature = "std")]
@@ -125,7 +134,18 @@ pub struct RefundBuilder<'a, T: secp256k1::Signing> {
        secp_ctx: Option<&'a Secp256k1<T>>,
 }
 
-impl<'a> RefundBuilder<'a, secp256k1::SignOnly> {
+/// Builds a [`Refund`] for the "offer for money" flow.
+///
+/// See [module-level documentation] for usage.
+///
+/// [module-level documentation]: self
+#[cfg(c_bindings)]
+pub struct RefundMaybeWithDerivedMetadataBuilder<'a> {
+       refund: RefundContents,
+       secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
+}
+
+macro_rules! refund_explicit_metadata_builder_methods { () => {
        /// 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.
        ///
@@ -156,9 +176,11 @@ impl<'a> RefundBuilder<'a, secp256k1::SignOnly> {
                        secp_ctx: None,
                })
        }
-}
+} }
 
-impl<'a, T: secp256k1::Signing> RefundBuilder<'a, T> {
+macro_rules! refund_builder_methods { (
+       $self: ident, $self_type: ty, $return_type: ty, $return_value: expr, $secp_context: ty $(, $self_mut: tt)?
+) => {
        /// Similar to [`RefundBuilder::new`] except, if [`RefundBuilder::path`] is called, the payer id
        /// is derived from the given [`ExpandedKey`] and nonce. This provides sender privacy by using a
        /// different payer id for each refund, assuming a different nonce is used.  Otherwise, the
@@ -174,7 +196,7 @@ impl<'a, T: secp256k1::Signing> RefundBuilder<'a, T> {
        /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
        pub fn deriving_payer_id<ES: Deref>(
                description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
-               secp_ctx: &'a Secp256k1<T>, amount_msats: u64, payment_id: PaymentId
+               secp_ctx: &'a Secp256k1<$secp_context>, amount_msats: u64, payment_id: PaymentId
        ) -> Result<Self, Bolt12SemanticError> where ES::Target: EntropySource {
                if amount_msats > MAX_VALUE_MSAT {
                        return Err(Bolt12SemanticError::InvalidAmount);
@@ -198,17 +220,17 @@ impl<'a, T: secp256k1::Signing> RefundBuilder<'a, T> {
        /// already passed is valid and can be checked for using [`Refund::is_expired`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
-               self.refund.absolute_expiry = Some(absolute_expiry);
-               self
+       pub fn absolute_expiry($($self_mut)* $self: $self_type, absolute_expiry: Duration) -> $return_type {
+               $self.refund.absolute_expiry = Some(absolute_expiry);
+               $return_value
        }
 
        /// Sets the [`Refund::issuer`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn issuer(mut self, issuer: String) -> Self {
-               self.refund.issuer = Some(issuer);
-               self
+       pub fn issuer($($self_mut)* $self: $self_type, issuer: String) -> $return_type {
+               $self.refund.issuer = Some(issuer);
+               $return_value
        }
 
        /// Adds a blinded path to [`Refund::paths`]. Must include at least one path if only connected
@@ -216,26 +238,26 @@ impl<'a, T: secp256k1::Signing> RefundBuilder<'a, T> {
        ///
        /// Successive calls to this method will add another blinded path. Caller is responsible for not
        /// adding duplicate paths.
-       pub fn path(mut self, path: BlindedPath) -> Self {
-               self.refund.paths.get_or_insert_with(Vec::new).push(path);
-               self
+       pub fn path($($self_mut)* $self: $self_type, path: BlindedPath) -> $return_type {
+               $self.refund.paths.get_or_insert_with(Vec::new).push(path);
+               $return_value
        }
 
        /// Sets the [`Refund::chain`] of the given [`Network`] for paying an invoice. If not
        /// called, [`Network::Bitcoin`] is assumed.
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn chain(self, network: Network) -> Self {
-               self.chain_hash(ChainHash::using_genesis_block(network))
+       pub fn chain($self: $self_type, network: Network) -> $return_type {
+               $self.chain_hash(ChainHash::using_genesis_block(network))
        }
 
        /// Sets the [`Refund::chain`] of the given [`ChainHash`] for paying an invoice. If not called,
        /// [`Network::Bitcoin`] is assumed.
        ///
        /// Successive calls to this method will override the previous setting.
-       pub(crate) fn chain_hash(mut self, chain: ChainHash) -> Self {
-               self.refund.chain = Some(chain);
-               self
+       pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> $return_type {
+               $self.refund.chain = Some(chain);
+               $return_value
        }
 
        /// Sets [`Refund::quantity`] of items. This is purely for informational purposes. It is useful
@@ -247,65 +269,109 @@ impl<'a, T: secp256k1::Signing> RefundBuilder<'a, T> {
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        /// [`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
+       pub fn quantity($($self_mut)* $self: $self_type, quantity: u64) -> $return_type {
+               $self.refund.quantity = Some(quantity);
+               $return_value
        }
 
        /// Sets the [`Refund::payer_note`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn payer_note(mut self, payer_note: String) -> Self {
-               self.refund.payer_note = Some(payer_note);
-               self
+       pub fn payer_note($($self_mut)* $self: $self_type, payer_note: String) -> $return_type {
+               $self.refund.payer_note = Some(payer_note);
+               $return_value
        }
 
        /// Builds a [`Refund`] after checking for valid semantics.
-       pub fn build(mut self) -> Result<Refund, Bolt12SemanticError> {
-               if self.refund.chain() == self.refund.implied_chain() {
-                       self.refund.chain = None;
+       pub fn build($($self_mut)* $self: $self_type) -> Result<Refund, Bolt12SemanticError> {
+               if $self.refund.chain() == $self.refund.implied_chain() {
+                       $self.refund.chain = None;
                }
 
                // Create the metadata for stateless verification of a Bolt12Invoice.
-               if self.refund.payer.0.has_derivation_material() {
-                       let mut metadata = core::mem::take(&mut self.refund.payer.0);
+               if $self.refund.payer.0.has_derivation_material() {
+                       let mut metadata = core::mem::take(&mut $self.refund.payer.0);
 
-                       if self.refund.paths.is_none() {
+                       if $self.refund.paths.is_none() {
                                metadata = metadata.without_keys();
                        }
 
-                       let mut tlv_stream = self.refund.as_tlv_stream();
+                       let mut tlv_stream = $self.refund.as_tlv_stream();
                        tlv_stream.0.metadata = None;
                        if metadata.derives_payer_keys() {
                                tlv_stream.2.payer_id = None;
                        }
 
-                       let (derived_metadata, keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
+                       let (derived_metadata, keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
                        metadata = derived_metadata;
                        if let Some(keys) = keys {
-                               self.refund.payer_id = keys.public_key();
+                               $self.refund.payer_id = keys.public_key();
                        }
 
-                       self.refund.payer.0 = metadata;
+                       $self.refund.payer.0 = metadata;
                }
 
                let mut bytes = Vec::new();
-               self.refund.write(&mut bytes).unwrap();
+               $self.refund.write(&mut bytes).unwrap();
+
+               Ok(Refund {
+                       bytes,
+                       #[cfg(not(c_bindings))]
+                       contents: $self.refund,
+                       #[cfg(c_bindings)]
+                       contents: $self.refund.clone(),
+               })
+       }
+} }
+
+#[cfg(test)]
+macro_rules! refund_builder_test_methods { (
+       $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
+) => {
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       pub(crate) fn clear_paths($($self_mut)* $self: $self_type) -> $return_type {
+               $self.refund.paths = None;
+               $return_value
+       }
 
-               Ok(Refund { bytes, contents: self.refund })
+       #[cfg_attr(c_bindings, allow(dead_code))]
+       fn features_unchecked($($self_mut)* $self: $self_type, features: InvoiceRequestFeatures) -> $return_type {
+               $self.refund.features = features;
+               $return_value
        }
+} }
+
+impl<'a> RefundBuilder<'a, secp256k1::SignOnly> {
+       refund_explicit_metadata_builder_methods!();
 }
 
-#[cfg(test)]
 impl<'a, T: secp256k1::Signing> RefundBuilder<'a, T> {
-       pub(crate) fn clear_paths(mut self) -> Self {
-               self.refund.paths = None;
-               self
-       }
+       refund_builder_methods!(self, Self, Self, self, T, mut);
+
+       #[cfg(test)]
+       refund_builder_test_methods!(self, Self, Self, self, mut);
+}
+
+#[cfg(all(c_bindings, not(test)))]
+impl<'a> RefundMaybeWithDerivedMetadataBuilder<'a> {
+       refund_explicit_metadata_builder_methods!();
+       refund_builder_methods!(self, &mut Self, (), (), secp256k1::All);
+}
+
+#[cfg(all(c_bindings, test))]
+impl<'a> RefundMaybeWithDerivedMetadataBuilder<'a> {
+       refund_explicit_metadata_builder_methods!();
+       refund_builder_methods!(self, &mut Self, &mut Self, self, secp256k1::All);
+       refund_builder_test_methods!(self, &mut Self, &mut Self, self);
+}
 
-       fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
-               self.refund.features = features;
-               self
+#[cfg(c_bindings)]
+impl<'a> From<RefundBuilder<'a, secp256k1::All>>
+for RefundMaybeWithDerivedMetadataBuilder<'a> {
+       fn from(builder: RefundBuilder<'a, secp256k1::All>) -> Self {
+               let RefundBuilder { refund, secp_ctx } = builder;
+
+               Self { refund, secp_ctx }
        }
 }
 
@@ -423,7 +489,9 @@ impl Refund {
        pub fn payer_note(&self) -> Option<PrintableString> {
                self.contents.payer_note()
        }
+}
 
+macro_rules! respond_with_explicit_signing_pubkey_methods { ($self: ident, $builder: ty) => {
        /// Creates an [`InvoiceBuilder`] for the refund with the given required fields and using the
        /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
        ///
@@ -435,14 +503,14 @@ impl Refund {
        /// [`Duration`]: core::time::Duration
        #[cfg(feature = "std")]
        pub fn respond_with(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
+               &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
                signing_pubkey: PublicKey,
-       ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
+       ) -> Result<$builder, Bolt12SemanticError> {
                let created_at = std::time::SystemTime::now()
                        .duration_since(std::time::SystemTime::UNIX_EPOCH)
                        .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 
-               self.respond_with_no_std(payment_paths, payment_hash, signing_pubkey, created_at)
+               $self.respond_with_no_std(payment_paths, payment_hash, signing_pubkey, created_at)
        }
 
        /// Creates an [`InvoiceBuilder`] for the refund with the given required fields.
@@ -468,16 +536,18 @@ impl Refund {
        ///
        /// [`Bolt12Invoice::created_at`]: crate::offers::invoice::Bolt12Invoice::created_at
        pub fn respond_with_no_std(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
+               &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
                signing_pubkey: PublicKey, created_at: Duration
-       ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
-               if self.features().requires_unknown_bits() {
+       ) -> Result<$builder, Bolt12SemanticError> {
+               if $self.features().requires_unknown_bits() {
                        return Err(Bolt12SemanticError::UnknownRequiredFeatures);
                }
 
-               InvoiceBuilder::for_refund(self, payment_paths, created_at, payment_hash, signing_pubkey)
+               <$builder>::for_refund($self, payment_paths, created_at, payment_hash, signing_pubkey)
        }
+} }
 
+macro_rules! respond_with_derived_signing_pubkey_methods { ($self: ident, $builder: ty) => {
        /// Creates an [`InvoiceBuilder`] for the refund using the given required fields and that uses
        /// derived signing keys to sign the [`Bolt12Invoice`].
        ///
@@ -488,9 +558,9 @@ impl Refund {
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        #[cfg(feature = "std")]
        pub fn respond_using_derived_keys<ES: Deref>(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
+               &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
                expanded_key: &ExpandedKey, entropy_source: ES
-       ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError>
+       ) -> Result<$builder, Bolt12SemanticError>
        where
                ES::Target: EntropySource,
        {
@@ -498,7 +568,7 @@ impl Refund {
                        .duration_since(std::time::SystemTime::UNIX_EPOCH)
                        .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 
-               self.respond_using_derived_keys_no_std(
+               $self.respond_using_derived_keys_no_std(
                        payment_paths, payment_hash, created_at, expanded_key, entropy_source
                )
        }
@@ -512,22 +582,36 @@ impl Refund {
        ///
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        pub fn respond_using_derived_keys_no_std<ES: Deref>(
-               &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
+               &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
                created_at: core::time::Duration, expanded_key: &ExpandedKey, entropy_source: ES
-       ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError>
+       ) -> Result<$builder, Bolt12SemanticError>
        where
                ES::Target: EntropySource,
        {
-               if self.features().requires_unknown_bits() {
+               if $self.features().requires_unknown_bits() {
                        return Err(Bolt12SemanticError::UnknownRequiredFeatures);
                }
 
                let nonce = Nonce::from_entropy_source(entropy_source);
                let keys = signer::derive_keys(nonce, expanded_key);
-               InvoiceBuilder::for_refund_using_keys(self, payment_paths, created_at, payment_hash, keys)
+               <$builder>::for_refund_using_keys($self, payment_paths, created_at, payment_hash, keys)
        }
+} }
 
-       #[cfg(test)]
+#[cfg(not(c_bindings))]
+impl Refund {
+       respond_with_explicit_signing_pubkey_methods!(self, InvoiceBuilder<ExplicitSigningPubkey>);
+       respond_with_derived_signing_pubkey_methods!(self, InvoiceBuilder<DerivedSigningPubkey>);
+}
+
+#[cfg(c_bindings)]
+impl Refund {
+       respond_with_explicit_signing_pubkey_methods!(self, InvoiceWithExplicitSigningPubkeyBuilder);
+       respond_with_derived_signing_pubkey_methods!(self, InvoiceWithDerivedSigningPubkeyBuilder);
+}
+
+#[cfg(test)]
+impl Refund {
        fn as_tlv_stream(&self) -> RefundTlvStreamRef {
                self.contents.as_tlv_stream()
        }
@@ -797,7 +881,15 @@ impl core::fmt::Display for Refund {
 
 #[cfg(test)]
 mod tests {
-       use super::{Refund, RefundBuilder, RefundTlvStreamRef};
+       use super::{Refund, RefundTlvStreamRef};
+       #[cfg(not(c_bindings))]
+       use {
+               super::RefundBuilder,
+       };
+       #[cfg(c_bindings)]
+       use {
+               super::RefundMaybeWithDerivedMetadataBuilder as RefundBuilder,
+       };
 
        use bitcoin::blockdata::constants::ChainHash;
        use bitcoin::network::constants::Network;
index 39122472eacb5513640f7fd78020a10ea783957d..29bed53d83f561f030e4966373c4403020ac6ffc 100644 (file)
@@ -11,7 +11,7 @@
 
 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
 use bitcoin::secp256k1::schnorr::Signature;
-use core::convert::{AsRef, Infallible};
+use core::convert::AsRef; 
 use core::time::Duration;
 use crate::blinded_path::{BlindedHop, BlindedPath};
 use crate::sign::EntropySource;
@@ -20,12 +20,16 @@ use crate::ln::features::BlindedHopFeatures;
 use crate::offers::invoice::BlindedPayInfo;
 use crate::offers::merkle::TaggedHash;
 
+pub(crate) fn fail_sign<T: AsRef<TaggedHash>>(_message: &T) -> Result<Signature, ()> {
+       Err(())
+}
+
 pub(crate) fn payer_keys() -> KeyPair {
        let secp_ctx = Secp256k1::new();
        KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
 }
 
-pub(crate) fn payer_sign<T: AsRef<TaggedHash>>(message: &T) -> Result<Signature, Infallible> {
+pub(crate) fn payer_sign<T: AsRef<TaggedHash>>(message: &T) -> Result<Signature, ()> {
        let secp_ctx = Secp256k1::new();
        let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
        Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
@@ -40,7 +44,7 @@ pub(crate) fn recipient_keys() -> KeyPair {
        KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap())
 }
 
-pub(crate) fn recipient_sign<T: AsRef<TaggedHash>>(message: &T) -> Result<Signature, Infallible> {
+pub(crate) fn recipient_sign<T: AsRef<TaggedHash>>(message: &T) -> Result<Signature, ()> {
        let secp_ctx = Secp256k1::new();
        let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
        Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))