Static invoice encoding and parsing
[rust-lightning] / lightning / src / offers / invoice_request.rs
index 9157613fcd977a132e9f7b5751f196af0592269a..cdf94a2e80d5bee168deea35fdb03c817718cdc7 100644 (file)
@@ -23,8 +23,8 @@
 //! extern crate bitcoin;
 //! extern crate lightning;
 //!
-//! use bitcoin::network::constants::Network;
-//! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
+//! use bitcoin::network::Network;
+//! use bitcoin::secp256k1::{Keypair, PublicKey, Secp256k1, SecretKey};
 //! use lightning::ln::features::OfferFeatures;
 //! use lightning::offers::invoice_request::UnsignedInvoiceRequest;
 //! use lightning::offers::offer::Offer;
@@ -32,7 +32,7 @@
 //!
 //! # fn parse() -> Result<(), lightning::offers::parse::Bolt12ParseError> {
 //! let secp_ctx = Secp256k1::new();
-//! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
+//! let keys = Keypair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
 //! let pubkey = PublicKey::from(keys);
 //! let mut buffer = Vec::new();
 //!
 //! ```
 
 use bitcoin::blockdata::constants::ChainHash;
-use bitcoin::network::constants::Network;
-use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
+use bitcoin::network::Network;
+use bitcoin::secp256k1::{Keypair, PublicKey, Secp256k1, self};
 use bitcoin::secp256k1::schnorr::Signature;
 use core::ops::Deref;
 use crate::sign::EntropySource;
 use crate::io;
 use crate::blinded_path::BlindedPath;
-use crate::ln::PaymentHash;
+use crate::ln::types::PaymentHash;
 use crate::ln::channelmanager::PaymentId;
 use crate::ln::features::InvoiceRequestFeatures;
 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
@@ -303,7 +303,7 @@ macro_rules! invoice_request_builder_methods { (
        }
 
        fn build_with_checks($($self_mut)* $self: $self_type) -> Result<
-               (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<$secp_context>>),
+               (UnsignedInvoiceRequest, Option<Keypair>, Option<&'b Secp256k1<$secp_context>>),
                Bolt12SemanticError
        > {
                #[cfg(feature = "std")] {
@@ -334,7 +334,7 @@ macro_rules! invoice_request_builder_methods { (
        }
 
        fn build_without_checks($($self_mut)* $self: $self_type) ->
-               (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<$secp_context>>)
+               (UnsignedInvoiceRequest, Option<Keypair>, Option<&'b Secp256k1<$secp_context>>)
        {
                // Create the metadata for stateless verification of a Bolt12Invoice.
                let mut keys = None;
@@ -487,6 +487,7 @@ for InvoiceRequestBuilder<'a, 'b, DerivedPayerId, secp256k1::All> {
 ///
 /// This is serialized as a TLV stream, which includes TLV records from the originating message. As
 /// such, it may include unknown, odd TLV records.
+#[derive(Clone)]
 pub struct UnsignedInvoiceRequest {
        bytes: Vec<u8>,
        contents: InvoiceRequestContents,
@@ -621,7 +622,7 @@ pub struct VerifiedInvoiceRequest {
        /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
        /// [`respond_using_derived_keys`]: Self::respond_using_derived_keys
        /// [`respond_with`]: Self::respond_with
-       pub keys: Option<KeyPair>,
+       pub keys: Option<Keypair>,
 }
 
 /// The contents of an [`InvoiceRequest`], which may be shared with an [`Bolt12Invoice`].
@@ -747,7 +748,27 @@ macro_rules! invoice_request_respond_with_explicit_signing_pubkey_methods { (
                        return Err(Bolt12SemanticError::UnknownRequiredFeatures);
                }
 
-               <$builder>::for_offer(&$contents, payment_paths, created_at, payment_hash)
+               let signing_pubkey = match $contents.contents.inner.offer.signing_pubkey() {
+                       Some(signing_pubkey) => signing_pubkey,
+                       None => return Err(Bolt12SemanticError::MissingSigningPubkey),
+               };
+
+               <$builder>::for_offer(&$contents, payment_paths, created_at, payment_hash, signing_pubkey)
+       }
+
+       #[cfg(test)]
+       #[allow(dead_code)]
+       pub(super) fn respond_with_no_std_using_signing_pubkey(
+               &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
+               created_at: core::time::Duration, signing_pubkey: PublicKey
+       ) -> Result<$builder, Bolt12SemanticError> {
+               debug_assert!($contents.contents.inner.offer.signing_pubkey().is_none());
+
+               if $contents.invoice_request_features().requires_unknown_bits() {
+                       return Err(Bolt12SemanticError::UnknownRequiredFeatures);
+               }
+
+               <$builder>::for_offer(&$contents, payment_paths, created_at, payment_hash, signing_pubkey)
        }
 } }
 
@@ -855,6 +876,11 @@ macro_rules! invoice_request_respond_with_derived_signing_pubkey_methods { (
                        Some(keys) => keys,
                };
 
+               match $contents.contents.inner.offer.signing_pubkey() {
+                       Some(signing_pubkey) => debug_assert_eq!(signing_pubkey, keys.public_key()),
+                       None => return Err(Bolt12SemanticError::MissingSigningPubkey),
+               }
+
                <$builder>::for_offer_using_keys(
                        &$self.inner, payment_paths, created_at, payment_hash, keys
                )
@@ -877,14 +903,12 @@ impl VerifiedInvoiceRequest {
                let InvoiceRequestContents {
                        payer_id,
                        inner: InvoiceRequestContentsWithoutPayerId {
-                               payer: _, offer: _, chain: _, amount_msats, features, quantity, payer_note
+                               payer: _, offer: _, chain: _, amount_msats: _, features: _, quantity, payer_note
                        },
                } = &self.inner.contents;
 
                InvoiceRequestFields {
                        payer_id: *payer_id,
-                       amount_msats: *amount_msats,
-                       features: features.clone(),
                        quantity: *quantity,
                        payer_note_truncated: payer_note.clone()
                                .map(|mut s| { s.truncate(PAYER_NOTE_LIMIT); UntrustedString(s) }),
@@ -961,6 +985,7 @@ impl InvoiceRequestContentsWithoutPayerId {
                        quantity: self.quantity,
                        payer_id: None,
                        payer_note: self.payer_note.as_ref(),
+                       paths: None,
                };
 
                (payer, offer, invoice_request)
@@ -993,6 +1018,8 @@ pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
 
+// This TLV stream is used for both InvoiceRequest and Refund, but not all TLV records are valid for
+// InvoiceRequest as noted below.
 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
        (80, chain: ChainHash),
        (82, amount: (u64, HighZeroBytesDroppedBigSize)),
@@ -1000,6 +1027,8 @@ tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST
        (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
        (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
        (89, payer_note: (String, WithoutLength)),
+       // Only used for Refund since the onion message of an InvoiceRequest has a reply path.
+       (90, paths: (Vec<BlindedPath>, WithoutLength)),
 });
 
 type FullInvoiceRequestTlvStream =
@@ -1082,7 +1111,9 @@ impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
                let (
                        PayerTlvStream { metadata },
                        offer_tlv_stream,
-                       InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
+                       InvoiceRequestTlvStream {
+                               chain, amount, features, quantity, payer_id, payer_note, paths,
+                       },
                ) = tlv_stream;
 
                let payer = match metadata {
@@ -1109,6 +1140,10 @@ impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
                        Some(payer_id) => payer_id,
                };
 
+               if paths.is_some() {
+                       return Err(Bolt12SemanticError::UnexpectedPaths);
+               }
+
                Ok(InvoiceRequestContents {
                        inner: InvoiceRequestContentsWithoutPayerId {
                                payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
@@ -1126,15 +1161,6 @@ pub struct InvoiceRequestFields {
        /// A possibly transient pubkey used to sign the invoice request.
        pub payer_id: PublicKey,
 
-       /// The amount to pay in msats (i.e., the minimum lightning-payable unit for [`chain`]), which
-       /// must be greater than or equal to [`Offer::amount`], converted if necessary.
-       ///
-       /// [`chain`]: InvoiceRequest::chain
-       pub amount_msats: Option<u64>,
-
-       /// Features pertaining to requesting an invoice.
-       pub features: InvoiceRequestFeatures,
-
        /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
        pub quantity: Option<u64>,
 
@@ -1150,10 +1176,8 @@ impl Writeable for InvoiceRequestFields {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                write_tlv_fields!(writer, {
                        (0, self.payer_id, required),
-                       (2, self.amount_msats.map(|v| HighZeroBytesDroppedBigSize(v)), option),
-                       (4, WithoutLength(&self.features), required),
-                       (6, self.quantity.map(|v| HighZeroBytesDroppedBigSize(v)), option),
-                       (8, self.payer_note_truncated.as_ref().map(|s| WithoutLength(&s.0)), option),
+                       (2, self.quantity.map(|v| HighZeroBytesDroppedBigSize(v)), option),
+                       (4, self.payer_note_truncated.as_ref().map(|s| WithoutLength(&s.0)), option),
                });
                Ok(())
        }
@@ -1163,15 +1187,13 @@ impl Readable for InvoiceRequestFields {
        fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
                _init_and_read_len_prefixed_tlv_fields!(reader, {
                        (0, payer_id, required),
-                       (2, amount_msats, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
-                       (4, features, (option, encoding: (InvoiceRequestFeatures, WithoutLength))),
-                       (6, quantity, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
-                       (8, payer_note_truncated, (option, encoding: (String, WithoutLength))),
+                       (2, quantity, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
+                       (4, payer_note_truncated, (option, encoding: (String, WithoutLength))),
                });
-               let features = features.unwrap_or(InvoiceRequestFeatures::empty());
 
                Ok(InvoiceRequestFields {
-                       payer_id: payer_id.0.unwrap(), amount_msats, features, quantity,
+                       payer_id: payer_id.0.unwrap(),
+                       quantity,
                        payer_note_truncated: payer_note_truncated.map(|s| UntrustedString(s)),
                })
        }
@@ -1182,8 +1204,8 @@ mod tests {
        use super::{InvoiceRequest, InvoiceRequestFields, InvoiceRequestTlvStreamRef, PAYER_NOTE_LIMIT, SIGNATURE_TAG, UnsignedInvoiceRequest};
 
        use bitcoin::blockdata::constants::ChainHash;
-       use bitcoin::network::constants::Network;
-       use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
+       use bitcoin::network::Network;
+       use bitcoin::secp256k1::{Keypair, Secp256k1, SecretKey, self};
        use core::num::NonZeroU64;
        #[cfg(feature = "std")]
        use core::time::Duration;
@@ -1211,7 +1233,7 @@ mod tests {
 
        #[test]
        fn builds_invoice_request_with_defaults() {
-               let unsigned_invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let unsigned_invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1226,14 +1248,14 @@ mod tests {
                assert_eq!(unsigned_invoice_request.payer_metadata(), &[1; 32]);
                assert_eq!(unsigned_invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
                assert_eq!(unsigned_invoice_request.metadata(), None);
-               assert_eq!(unsigned_invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
-               assert_eq!(unsigned_invoice_request.description(), PrintableString("foo"));
+               assert_eq!(unsigned_invoice_request.amount(), Some(Amount::Bitcoin { amount_msats: 1000 }));
+               assert_eq!(unsigned_invoice_request.description(), Some(PrintableString("")));
                assert_eq!(unsigned_invoice_request.offer_features(), &OfferFeatures::empty());
                assert_eq!(unsigned_invoice_request.absolute_expiry(), None);
                assert_eq!(unsigned_invoice_request.paths(), &[]);
                assert_eq!(unsigned_invoice_request.issuer(), None);
                assert_eq!(unsigned_invoice_request.supported_quantity(), Quantity::One);
-               assert_eq!(unsigned_invoice_request.signing_pubkey(), recipient_pubkey());
+               assert_eq!(unsigned_invoice_request.signing_pubkey(), Some(recipient_pubkey()));
                assert_eq!(unsigned_invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
                assert_eq!(unsigned_invoice_request.amount_msats(), None);
                assert_eq!(unsigned_invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
@@ -1258,14 +1280,14 @@ mod tests {
                assert_eq!(invoice_request.payer_metadata(), &[1; 32]);
                assert_eq!(invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
                assert_eq!(invoice_request.metadata(), None);
-               assert_eq!(invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
-               assert_eq!(invoice_request.description(), PrintableString("foo"));
+               assert_eq!(invoice_request.amount(), Some(Amount::Bitcoin { amount_msats: 1000 }));
+               assert_eq!(invoice_request.description(), Some(PrintableString("")));
                assert_eq!(invoice_request.offer_features(), &OfferFeatures::empty());
                assert_eq!(invoice_request.absolute_expiry(), None);
                assert_eq!(invoice_request.paths(), &[]);
                assert_eq!(invoice_request.issuer(), None);
                assert_eq!(invoice_request.supported_quantity(), Quantity::One);
-               assert_eq!(invoice_request.signing_pubkey(), recipient_pubkey());
+               assert_eq!(invoice_request.signing_pubkey(), Some(recipient_pubkey()));
                assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
                assert_eq!(invoice_request.amount_msats(), None);
                assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
@@ -1285,7 +1307,7 @@ mod tests {
                                        metadata: None,
                                        currency: None,
                                        amount: Some(1000),
-                                       description: Some(&String::from("foo")),
+                                       description: Some(&String::from("")),
                                        features: None,
                                        absolute_expiry: None,
                                        paths: None,
@@ -1300,6 +1322,7 @@ mod tests {
                                        quantity: None,
                                        payer_id: Some(&payer_pubkey()),
                                        payer_note: None,
+                                       paths: None,
                                },
                                SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
                        ),
@@ -1316,7 +1339,7 @@ mod tests {
                let future_expiry = Duration::from_secs(u64::max_value());
                let past_expiry = Duration::from_secs(0);
 
-               if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
+               if let Err(e) = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .absolute_expiry(future_expiry)
                        .build().unwrap()
@@ -1326,7 +1349,7 @@ mod tests {
                        panic!("error building invoice_request: {:?}", e);
                }
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .absolute_expiry(past_expiry)
                        .build().unwrap()
@@ -1346,7 +1369,7 @@ mod tests {
                let secp_ctx = Secp256k1::new();
                let payment_id = PaymentId([1; 32]);
 
-               let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let offer = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap();
                let invoice_request = offer
@@ -1419,7 +1442,7 @@ mod tests {
                let secp_ctx = Secp256k1::new();
                let payment_id = PaymentId([1; 32]);
 
-               let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let offer = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap();
                let invoice_request = offer
@@ -1489,7 +1512,7 @@ mod tests {
                let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
                let testnet = ChainHash::using_genesis_block(Network::Testnet);
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1500,7 +1523,7 @@ mod tests {
                assert_eq!(invoice_request.chain(), mainnet);
                assert_eq!(tlv_stream.chain, None);
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .chain(Network::Testnet)
                        .build().unwrap()
@@ -1512,7 +1535,7 @@ mod tests {
                assert_eq!(invoice_request.chain(), testnet);
                assert_eq!(tlv_stream.chain, Some(&testnet));
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .chain(Network::Bitcoin)
                        .chain(Network::Testnet)
@@ -1525,7 +1548,7 @@ mod tests {
                assert_eq!(invoice_request.chain(), mainnet);
                assert_eq!(tlv_stream.chain, None);
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .chain(Network::Bitcoin)
                        .chain(Network::Testnet)
@@ -1539,7 +1562,7 @@ mod tests {
                assert_eq!(invoice_request.chain(), testnet);
                assert_eq!(tlv_stream.chain, Some(&testnet));
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .chain(Network::Testnet)
                        .build().unwrap()
@@ -1550,7 +1573,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
                }
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .chain(Network::Testnet)
                        .build().unwrap()
@@ -1564,7 +1587,7 @@ mod tests {
 
        #[test]
        fn builds_invoice_request_with_amount() {
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1575,7 +1598,7 @@ mod tests {
                assert_eq!(invoice_request.amount_msats(), Some(1000));
                assert_eq!(tlv_stream.amount, Some(1000));
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1587,7 +1610,7 @@ mod tests {
                assert_eq!(invoice_request.amount_msats(), Some(1000));
                assert_eq!(tlv_stream.amount, Some(1000));
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1598,7 +1621,7 @@ mod tests {
                assert_eq!(invoice_request.amount_msats(), Some(1001));
                assert_eq!(tlv_stream.amount, Some(1001));
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1608,7 +1631,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
                }
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Unbounded)
                        .build().unwrap()
@@ -1620,7 +1643,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
                }
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1630,7 +1653,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
                }
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Unbounded)
                        .build().unwrap()
@@ -1643,7 +1666,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
                }
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
                        .build()
@@ -1652,7 +1675,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12SemanticError::MissingAmount),
                }
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Unbounded)
                        .build().unwrap()
@@ -1667,7 +1690,7 @@ mod tests {
 
        #[test]
        fn builds_invoice_request_with_features() {
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1678,7 +1701,7 @@ mod tests {
                assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::unknown());
                assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1696,7 +1719,7 @@ mod tests {
                let one = NonZeroU64::new(1).unwrap();
                let ten = NonZeroU64::new(10).unwrap();
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::One)
                        .build().unwrap()
@@ -1707,7 +1730,7 @@ mod tests {
                assert_eq!(invoice_request.quantity(), None);
                assert_eq!(tlv_stream.quantity, None);
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::One)
                        .build().unwrap()
@@ -1719,7 +1742,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12SemanticError::UnexpectedQuantity),
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Bounded(ten))
                        .build().unwrap()
@@ -1732,7 +1755,7 @@ mod tests {
                assert_eq!(invoice_request.amount_msats(), Some(10_000));
                assert_eq!(tlv_stream.amount, Some(10_000));
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Bounded(ten))
                        .build().unwrap()
@@ -1744,7 +1767,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidQuantity),
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Unbounded)
                        .build().unwrap()
@@ -1757,7 +1780,7 @@ mod tests {
                assert_eq!(invoice_request.amount_msats(), Some(2_000));
                assert_eq!(tlv_stream.amount, Some(2_000));
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Unbounded)
                        .build().unwrap()
@@ -1768,7 +1791,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
                }
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Bounded(one))
                        .build().unwrap()
@@ -1782,7 +1805,7 @@ mod tests {
 
        #[test]
        fn builds_invoice_request_with_payer_note() {
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1793,7 +1816,7 @@ mod tests {
                assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
                assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1808,7 +1831,7 @@ mod tests {
 
        #[test]
        fn fails_signing_invoice_request() {
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1819,7 +1842,7 @@ mod tests {
                        Err(e) => assert_eq!(e, SignError::Signing),
                }
 
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1833,7 +1856,7 @@ mod tests {
 
        #[test]
        fn fails_responding_with_unknown_required_features() {
-               match OfferBuilder::new("foo".into(), recipient_pubkey())
+               match OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
@@ -1849,7 +1872,7 @@ mod tests {
 
        #[test]
        fn parses_invoice_request_with_metadata() {
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1866,7 +1889,7 @@ mod tests {
 
        #[test]
        fn parses_invoice_request_with_chain() {
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1881,7 +1904,7 @@ mod tests {
                        panic!("error parsing invoice_request: {:?}", e);
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1900,7 +1923,7 @@ mod tests {
 
        #[test]
        fn parses_invoice_request_with_amount() {
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1914,7 +1937,7 @@ mod tests {
                        panic!("error parsing invoice_request: {:?}", e);
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
                        .amount_msats(1000).unwrap()
@@ -1928,7 +1951,7 @@ mod tests {
                        panic!("error parsing invoice_request: {:?}", e);
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
                        .build_unchecked()
@@ -1942,7 +1965,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1958,7 +1981,8 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InsufficientAmount)),
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
+                       .description("foo".to_string())
                        .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
                        .build_unchecked()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -1975,7 +1999,7 @@ mod tests {
                        },
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Unbounded)
                        .build().unwrap()
@@ -1998,7 +2022,7 @@ mod tests {
                let one = NonZeroU64::new(1).unwrap();
                let ten = NonZeroU64::new(10).unwrap();
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::One)
                        .build().unwrap()
@@ -2013,7 +2037,7 @@ mod tests {
                        panic!("error parsing invoice_request: {:?}", e);
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::One)
                        .build().unwrap()
@@ -2033,7 +2057,7 @@ mod tests {
                        },
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Bounded(ten))
                        .build().unwrap()
@@ -2050,7 +2074,7 @@ mod tests {
                        panic!("error parsing invoice_request: {:?}", e);
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Bounded(ten))
                        .build().unwrap()
@@ -2068,7 +2092,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidQuantity)),
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Unbounded)
                        .build().unwrap()
@@ -2085,7 +2109,7 @@ mod tests {
                        panic!("error parsing invoice_request: {:?}", e);
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Unbounded)
                        .build().unwrap()
@@ -2101,7 +2125,7 @@ mod tests {
                        Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
                }
 
-               let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Bounded(one))
                        .build().unwrap()
@@ -2120,7 +2144,7 @@ mod tests {
 
        #[test]
        fn fails_parsing_invoice_request_without_metadata() {
-               let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let offer = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap();
                let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -2141,7 +2165,7 @@ mod tests {
 
        #[test]
        fn fails_parsing_invoice_request_without_payer_id() {
-               let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let offer = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap();
                let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -2160,7 +2184,7 @@ mod tests {
 
        #[test]
        fn fails_parsing_invoice_request_without_node_id() {
-               let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let offer = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap();
                let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -2182,7 +2206,7 @@ mod tests {
        #[test]
        fn fails_parsing_invoice_request_without_signature() {
                let mut buffer = Vec::new();
-               OfferBuilder::new("foo".into(), recipient_pubkey())
+               OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -2198,7 +2222,7 @@ mod tests {
 
        #[test]
        fn fails_parsing_invoice_request_with_invalid_signature() {
-               let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
+               let mut invoice_request = OfferBuilder::new(recipient_pubkey())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
@@ -2221,8 +2245,8 @@ mod tests {
        #[test]
        fn fails_parsing_invoice_request_with_extra_tlv_records() {
                let secp_ctx = Secp256k1::new();
-               let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
-               let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
+               let keys = Keypair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
+               let invoice_request = OfferBuilder::new(keys.public_key())
                        .amount_msats(1000)
                        .build().unwrap()
                        .request_invoice(vec![1; 32], keys.public_key()).unwrap()
@@ -2246,7 +2270,6 @@ mod tests {
 
        #[test]
        fn copies_verified_invoice_request_fields() {
-               let desc = "foo".to_string();
                let node_id = recipient_pubkey();
                let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
                let entropy = FixedEntropy {};
@@ -2255,16 +2278,15 @@ 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)
+                       ::deriving_signing_pubkey(node_id, &expanded_key, &entropy, &secp_ctx)
                        .chain(Network::Testnet)
                        .amount_msats(1000)
                        .supported_quantity(Quantity::Unbounded)
                        .build().unwrap();
-               assert_eq!(offer.signing_pubkey(), node_id);
+               assert_eq!(offer.signing_pubkey(), Some(node_id));
 
                let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
                        .chain(Network::Testnet).unwrap()
-                       .amount_msats(1001).unwrap()
                        .quantity(1).unwrap()
                        .payer_note("0".repeat(PAYER_NOTE_LIMIT * 2))
                        .build().unwrap()
@@ -2277,8 +2299,6 @@ mod tests {
                                        fields,
                                        InvoiceRequestFields {
                                                payer_id: payer_pubkey(),
-                                               amount_msats: Some(1001),
-                                               features: InvoiceRequestFeatures::empty(),
                                                quantity: Some(1),
                                                payer_note_truncated: Some(UntrustedString("0".repeat(PAYER_NOTE_LIMIT))),
                                        }