Allow(unused_imports) on prelude imports
[rust-lightning] / lightning / src / offers / invoice.rs
index 745b389fa4673d34141aa8d42a017594e64c8cdc..9b54927048aad1a476417e4558451eb7ba093431 100644 (file)
@@ -1,4 +1,4 @@
-// This file is Copyright its original authors, visible in version control
+    // This file is Copyright its original authors, visible in version control
 // history.
 //
 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
 //!
 //! 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!() }
 //! let secp_ctx = Secp256k1::new();
 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
 //! let pubkey = PublicKey::from(keys);
-//! let wpubkey_hash = bitcoin::util::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
+//! let wpubkey_hash = bitcoin::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
 //! 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)
 //! # let secp_ctx = Secp256k1::new();
 //! # let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
 //! # let pubkey = PublicKey::from(keys);
-//! # let wpubkey_hash = bitcoin::util::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
+//! # let wpubkey_hash = bitcoin::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
 //! # 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)
@@ -103,18 +108,19 @@ use bitcoin::hashes::Hash;
 use bitcoin::network::constants::Network;
 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
 use bitcoin::secp256k1::schnorr::Signature;
-use bitcoin::util::address::{Address, Payload, WitnessVersion};
-use bitcoin::util::schnorr::TweakedPublicKey;
-use core::convert::{AsRef, Infallible, TryFrom};
+use bitcoin::address::{Address, Payload, WitnessProgram, WitnessVersion};
+use bitcoin::key::TweakedPublicKey;
+use core::convert::{AsRef, TryFrom};
 use core::time::Duration;
 use crate::io;
 use crate::blinded_path::BlindedPath;
 use crate::ln::PaymentHash;
+use crate::ln::channelmanager::PaymentId;
 use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures, InvoiceRequestFeatures, OfferFeatures};
 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};
@@ -123,12 +129,13 @@ use crate::offers::signer;
 use crate::util::ser::{HighZeroBytesDroppedBigSize, Iterable, SeekReadable, WithoutLength, Writeable, Writer};
 use crate::util::string::PrintableString;
 
+#[allow(unused_imports)]
 use crate::prelude::*;
 
 #[cfg(feature = "std")]
 use std::time::SystemTime;
 
-const DEFAULT_RELATIVE_EXPIRY: Duration = Duration::from_secs(7200);
+pub(crate) const DEFAULT_RELATIVE_EXPIRY: Duration = Duration::from_secs(7200);
 
 /// Tag for the hash function used when signing a [`Bolt12Invoice`]'s merkle root.
 pub const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice", "signature");
@@ -150,6 +157,38 @@ 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.
@@ -168,12 +207,13 @@ 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
        ) -> Result<Self, Bolt12SemanticError> {
-               let amount_msats = Self::check_amount_msats(invoice_request)?;
+               let amount_msats = Self::amount_msats(invoice_request)?;
                let signing_pubkey = invoice_request.contents.inner.offer.signing_pubkey();
                let contents = InvoiceContents::ForOffer {
                        invoice_request: invoice_request.contents.clone(),
@@ -185,6 +225,7 @@ 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
@@ -199,14 +240,39 @@ 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
        ) -> Result<Self, Bolt12SemanticError> {
-               let amount_msats = Self::check_amount_msats(invoice_request)?;
+               let amount_msats = Self::amount_msats(invoice_request)?;
                let signing_pubkey = invoice_request.contents.inner.offer.signing_pubkey();
                let contents = InvoiceContents::ForOffer {
                        invoice_request: invoice_request.contents.clone(),
@@ -218,6 +284,7 @@ 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,
@@ -233,10 +300,46 @@ impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
 
                Self::new(&refund.bytes, contents, DerivedSigningPubkey(keys))
        }
-}
 
-impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
-       fn check_amount_msats(invoice_request: &InvoiceRequest) -> Result<u64, Bolt12SemanticError> {
+       /// 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> {
                match invoice_request.amount_msats() {
                        Some(amount_msats) => Ok(amount_msats),
                        None => match invoice_request.contents.inner.offer.amount() {
@@ -250,6 +353,7 @@ 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
@@ -260,8 +364,9 @@ 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: $type_param
        ) -> Result<Self, Bolt12SemanticError> {
                if contents.fields().payment_paths.is_empty() {
                        return Err(Bolt12SemanticError::MissingPaths);
@@ -275,96 +380,120 @@ impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
        /// [`Bolt12Invoice::is_expired`].
        ///
        /// Successive calls to this method will override the previous setting.
-       pub fn relative_expiry(mut self, relative_expiry_secs: u32) -> Self {
+       pub fn relative_expiry($($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.into_inner()[..]),
+                       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.into_inner()[..]),
+                       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);
-                       }
-               }
-
-               let InvoiceBuilder { invreq_bytes, invoice, .. } = self;
-               Ok(UnsignedBolt12Invoice::new(invreq_bytes, invoice))
-       }
+       invoice_explicit_signing_pubkey_builder_methods!(self, Self);
 }
 
 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);
-                       }
+       invoice_derived_signing_pubkey_builder_methods!(self, Self);
+}
+
+impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
+       invoice_builder_methods!(self, Self, Self, self, S, mut);
+}
+
+#[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(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,
+               }
        }
 }
 
@@ -380,6 +509,30 @@ 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
@@ -397,30 +550,54 @@ impl UnsignedBolt12Invoice {
                Self { bytes, contents, tagged_hash }
        }
 
+       /// Returns the [`TaggedHash`] of the invoice to sign.
+       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,
+                       #[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 {
@@ -443,6 +620,7 @@ pub struct Bolt12Invoice {
        bytes: Vec<u8>,
        contents: InvoiceContents,
        signature: Signature,
+       tagged_hash: TaggedHash,
 }
 
 /// The contents of an [`Bolt12Invoice`] for responding to either an [`Offer`] or a [`Refund`].
@@ -687,18 +865,18 @@ impl Bolt12Invoice {
 
        /// Hash that was used for signing the invoice.
        pub fn signable_hash(&self) -> [u8; 32] {
-               merkle::message_digest(SIGNATURE_TAG, &self.bytes).as_ref().clone()
+               self.tagged_hash.as_digest().as_ref().clone()
        }
 
-       /// Verifies that the invoice was for a request or refund created using the given key.
+       /// Verifies that the invoice was for a request or refund created using the given key. Returns
+       /// the associated [`PaymentId`] to use when sending the payment.
        pub fn verify<T: secp256k1::Signing>(
                &self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
-       ) -> bool {
+       ) -> Result<PaymentId, ()> {
                self.contents.verify(TlvStream::new(&self.bytes), key, secp_ctx)
        }
 
-       #[cfg(test)]
-       pub(super) fn as_tlv_stream(&self) -> FullInvoiceTlvStreamRef {
+       pub(crate) fn as_tlv_stream(&self) -> FullInvoiceTlvStreamRef {
                let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream) =
                        self.contents.as_tlv_stream();
                let signature_tlv_stream = SignatureTlvStreamRef {
@@ -720,6 +898,16 @@ impl InvoiceContents {
                }
        }
 
+       #[cfg(not(feature = "std"))]
+       fn is_offer_or_refund_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
+               match self {
+                       InvoiceContents::ForOffer { invoice_request, .. } =>
+                               invoice_request.inner.offer.is_expired_no_std(duration_since_epoch),
+                       InvoiceContents::ForRefund { refund, .. } =>
+                               refund.is_expired_no_std(duration_since_epoch),
+               }
+       }
+
        fn offer_chains(&self) -> Option<Vec<ChainHash>> {
                match self {
                        InvoiceContents::ForOffer { invoice_request, .. } =>
@@ -893,23 +1081,11 @@ impl InvoiceContents {
                        };
 
                        let program = &address.program;
-                       if program.len() < 2 || program.len() > 40 {
-                               return None;
-                       }
-
-                       let address = Address {
-                               payload: Payload::WitnessProgram {
-                                       version,
-                                       program: program.clone(),
-                               },
-                               network,
+                       let witness_program = match WitnessProgram::new(version, program.clone()) {
+                               Ok(witness_program) => witness_program,
+                               Err(_) => return None,
                        };
-
-                       if !address.is_standard() && version == WitnessVersion::V0 {
-                               return None;
-                       }
-
-                       Some(address)
+                       Some(Address::new(network, Payload::WitnessProgram(witness_program)))
                };
 
                self.fields().fallbacks
@@ -942,7 +1118,7 @@ impl InvoiceContents {
 
        fn verify<T: secp256k1::Signing>(
                &self, tlv_stream: TlvStream<'_>, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
-       ) -> bool {
+       ) -> Result<PaymentId, ()> {
                let offer_records = tlv_stream.clone().range(OFFER_TYPES);
                let invreq_records = tlv_stream.range(INVOICE_REQUEST_TYPES).filter(|record| {
                        match record.r#type {
@@ -962,10 +1138,7 @@ impl InvoiceContents {
                        },
                };
 
-               match signer::verify_metadata(metadata, key, iv_bytes, payer_id, tlv_stream, secp_ctx) {
-                       Ok(_) => true,
-                       Err(()) => false,
-               }
+               signer::verify_payer_metadata(metadata, key, iv_bytes, payer_id, tlv_stream, secp_ctx)
        }
 
        fn derives_keys(&self) -> bool {
@@ -1125,7 +1298,6 @@ impl_writeable!(FallbackAddress, { version, program });
 type FullInvoiceTlvStream =
        (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream, SignatureTlvStream);
 
-#[cfg(test)]
 type FullInvoiceTlvStreamRef<'a> = (
        PayerTlvStreamRef<'a>,
        OfferTlvStreamRef<'a>,
@@ -1184,11 +1356,11 @@ impl TryFrom<ParsedMessage<FullInvoiceTlvStream>> for Bolt12Invoice {
                        None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
                        Some(signature) => signature,
                };
-               let message = TaggedHash::new(SIGNATURE_TAG, &bytes);
+               let tagged_hash = TaggedHash::new(SIGNATURE_TAG, &bytes);
                let pubkey = contents.fields().signing_pubkey;
-               merkle::verify_signature(&signature, message, pubkey)?;
+               merkle::verify_signature(&signature, &tagged_hash, pubkey)?;
 
-               Ok(Bolt12Invoice { bytes, contents, signature })
+               Ok(Bolt12Invoice { bytes, contents, signature, tagged_hash })
        }
 }
 
@@ -1275,12 +1447,12 @@ mod tests {
        use super::{Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, FallbackAddress, FullInvoiceTlvStreamRef, InvoiceTlvStreamRef, SIGNATURE_TAG, UnsignedBolt12Invoice};
 
        use bitcoin::blockdata::constants::ChainHash;
-       use bitcoin::blockdata::script::Script;
+       use bitcoin::blockdata::script::ScriptBuf;
        use bitcoin::hashes::Hash;
        use bitcoin::network::constants::Network;
        use bitcoin::secp256k1::{Message, Secp256k1, XOnlyPublicKey, self};
-       use bitcoin::util::address::{Address, Payload, WitnessVersion};
-       use bitcoin::util::schnorr::TweakedPublicKey;
+       use bitcoin::address::{Address, Payload, WitnessProgram, WitnessVersion};
+       use bitcoin::key::TweakedPublicKey;
        use core::convert::TryFrom;
        use core::time::Duration;
        use crate::blinded_path::{BlindedHop, BlindedPath};
@@ -1290,10 +1462,19 @@ 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;
@@ -1368,6 +1549,8 @@ mod tests {
                        },
                }
 
+               #[cfg(c_bindings)]
+               let mut unsigned_invoice = unsigned_invoice;
                let invoice = unsigned_invoice.sign(recipient_sign).unwrap();
 
                let mut buffer = Vec::new();
@@ -1403,7 +1586,7 @@ mod tests {
                assert_eq!(invoice.signing_pubkey(), recipient_pubkey());
 
                let message = TaggedHash::new(SIGNATURE_TAG, &invoice.bytes);
-               assert!(merkle::verify_signature(&invoice.signature, message, recipient_pubkey()).is_ok());
+               assert!(merkle::verify_signature(&invoice.signature, &message, recipient_pubkey()).is_ok());
 
                let digest = Message::from_slice(&invoice.signable_hash()).unwrap();
                let pubkey = recipient_pubkey().into();
@@ -1500,7 +1683,7 @@ mod tests {
                assert_eq!(invoice.signing_pubkey(), recipient_pubkey());
 
                let message = TaggedHash::new(SIGNATURE_TAG, &invoice.bytes);
-               assert!(merkle::verify_signature(&invoice.signature, message, recipient_pubkey()).is_ok());
+               assert!(merkle::verify_signature(&invoice.signature, &message, recipient_pubkey()).is_ok());
 
                assert_eq!(
                        invoice.as_tlv_stream(),
@@ -1628,6 +1811,8 @@ 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)
@@ -1637,36 +1822,31 @@ mod tests {
                        .build().unwrap()
                        .sign(payer_sign).unwrap();
 
-               if let Err(e) = invoice_request
-                       .verify_and_respond_using_derived_keys_no_std(
-                               payment_paths(), payment_hash(), now(), &expanded_key, &secp_ctx
-                       )
-                       .unwrap()
+               if let Err(e) = invoice_request.clone()
+                       .verify(&expanded_key, &secp_ctx).unwrap()
+                       .respond_using_derived_keys_no_std(payment_paths(), payment_hash(), now()).unwrap()
                        .build_and_sign(&secp_ctx)
                {
                        panic!("error building invoice: {:?}", e);
                }
 
                let expanded_key = ExpandedKey::new(&KeyMaterial([41; 32]));
-               match invoice_request.verify_and_respond_using_derived_keys_no_std(
-                       payment_paths(), payment_hash(), now(), &expanded_key, &secp_ctx
-               ) {
-                       Ok(_) => panic!("expected error"),
-                       Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidMetadata),
-               }
+               assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
 
                let desc = "foo".to_string();
                let offer = OfferBuilder
                        ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
                        .amount_msats(1000)
+                       // Omit the path so that node_id is used for the signing pubkey instead of deriving
                        .build().unwrap();
                let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
                        .build().unwrap()
                        .sign(payer_sign).unwrap();
 
-               match invoice_request.verify_and_respond_using_derived_keys_no_std(
-                       payment_paths(), payment_hash(), now(), &expanded_key, &secp_ctx
-               ) {
+               match invoice_request
+                       .verify(&expanded_key, &secp_ctx).unwrap()
+                       .respond_using_derived_keys_no_std(payment_paths(), payment_hash(), now())
+               {
                        Ok(_) => panic!("expected error"),
                        Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidMetadata),
                }
@@ -1781,8 +1961,8 @@ mod tests {
 
        #[test]
        fn builds_invoice_with_fallback_address() {
-               let script = Script::new();
-               let pubkey = bitcoin::util::key::PublicKey::new(recipient_pubkey());
+               let script = ScriptBuf::new();
+               let pubkey = bitcoin::key::PublicKey::new(recipient_pubkey());
                let x_only_pubkey = XOnlyPublicKey::from_keypair(&recipient_keys()).0;
                let tweaked_pubkey = TweakedPublicKey::dangerous_assume_tweaked(x_only_pubkey);
 
@@ -1812,11 +1992,11 @@ mod tests {
                        Some(&vec![
                                FallbackAddress {
                                        version: WitnessVersion::V0.to_num(),
-                                       program: Vec::from(&script.wscript_hash().into_inner()[..]),
+                                       program: Vec::from(script.wscript_hash().to_byte_array()),
                                },
                                FallbackAddress {
                                        version: WitnessVersion::V0.to_num(),
-                                       program: Vec::from(&pubkey.wpubkey_hash().unwrap().into_inner()[..]),
+                                       program: Vec::from(pubkey.wpubkey_hash().unwrap().to_byte_array()),
                                },
                                FallbackAddress {
                                        version: WitnessVersion::V1.to_num(),
@@ -1856,10 +2036,10 @@ 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())
@@ -2070,8 +2250,8 @@ mod tests {
 
        #[test]
        fn parses_invoice_with_fallback_address() {
-               let script = Script::new();
-               let pubkey = bitcoin::util::key::PublicKey::new(recipient_pubkey());
+               let script = ScriptBuf::new();
+               let pubkey = bitcoin::key::PublicKey::new(recipient_pubkey());
                let x_only_pubkey = XOnlyPublicKey::from_keypair(&recipient_keys()).0;
                let tweaked_pubkey = TweakedPublicKey::dangerous_assume_tweaked(x_only_pubkey);
 
@@ -2082,11 +2262,18 @@ 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();
@@ -2104,26 +2291,16 @@ mod tests {
 
                match Bolt12Invoice::try_from(buffer) {
                        Ok(invoice) => {
+                               let v1_witness_program = WitnessProgram::new(WitnessVersion::V1, vec![0u8; 33]).unwrap();
+                               let v2_witness_program = WitnessProgram::new(WitnessVersion::V2, vec![0u8; 40]).unwrap();
                                assert_eq!(
                                        invoice.fallbacks(),
                                        vec![
                                                Address::p2wsh(&script, Network::Bitcoin),
                                                Address::p2wpkh(&pubkey, Network::Bitcoin).unwrap(),
                                                Address::p2tr_tweaked(tweaked_pubkey, Network::Bitcoin),
-                                               Address {
-                                                       payload: Payload::WitnessProgram {
-                                                               version: WitnessVersion::V1,
-                                                               program: vec![0u8; 33],
-                                                       },
-                                                       network: Network::Bitcoin,
-                                               },
-                                               Address {
-                                                       payload: Payload::WitnessProgram {
-                                                               version: WitnessVersion::V2,
-                                                               program: vec![0u8; 40],
-                                                       },
-                                                       network: Network::Bitcoin,
-                                               },
+                                               Address::new(Network::Bitcoin, Payload::WitnessProgram(v1_witness_program)),
+                                               Address::new(Network::Bitcoin, Payload::WitnessProgram(v2_witness_program)),
                                        ],
                                );
                        },