_ Git - rust-lightning/blob - lightning/src/offers/offer.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Data structures and encoding for `offer` messages.
  11 //!
  12 //! An [`Offer`] represents an "offer to be paid." It is typically constructed by a merchant and
  13 //! published as a QR code to be scanned by a customer. The customer uses the offer to request an
  14 //! invoice from the merchant to be paid.
  15 //!
  16 //! # Example
  17 //!
  18 //! ```
  19 //! extern crate bitcoin;
  20 //! extern crate core;
  21 //! extern crate lightning;
  22 //!
  23 //! use core::convert::TryFrom;
  24 //! use core::num::NonZeroU64;
  25 //! use core::time::Duration;
  26 //!
  27 //! use bitcoin::secp256k1::{Keypair, PublicKey, Secp256k1, SecretKey};
  28 //! use lightning::offers::offer::{Offer, OfferBuilder, Quantity};
  29 //! use lightning::offers::parse::Bolt12ParseError;
  30 //! use lightning::util::ser::{Readable, Writeable};
  31 //!
  32 //! # use lightning::blinded_path::BlindedPath;
  33 //! # #[cfg(feature = "std")]
  34 //! # use std::time::SystemTime;
  35 //! #
  36 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
  37 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
  38 //! #
  39 //! # #[cfg(feature = "std")]
  40 //! # fn build() -> Result<(), Bolt12ParseError> {
  41 //! let secp_ctx = Secp256k1::new();
  42 //! let keys = Keypair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
  43 //! let pubkey = PublicKey::from(keys);
  44 //!
  45 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
  46 //! let offer = OfferBuilder::new(pubkey)
  47 //!     .description("coffee, large".to_string())
  48 //!     .amount_msats(20_000)
  49 //!     .supported_quantity(Quantity::Unbounded)
  50 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  51 //!     .issuer("Foo Bar".to_string())
  52 //!     .path(create_blinded_path())
  53 //!     .path(create_another_blinded_path())
  54 //!     .build()?;
  55 //!
  56 //! // Encode as a bech32 string for use in a QR code.
  57 //! let encoded_offer = offer.to_string();
  58 //!
  59 //! // Parse from a bech32 string after scanning from a QR code.
  60 //! let offer = encoded_offer.parse::<Offer>()?;
  61 //!
  62 //! // Encode offer as raw bytes.
  63 //! let mut bytes = Vec::new();
  64 //! offer.write(&mut bytes).unwrap();
  65 //!
  66 //! // Decode raw bytes into an offer.
  67 //! let offer = Offer::try_from(bytes)?;
  68 //! # Ok(())
  69 //! # }
  70 //! ```
  71 //!
  72 //! # Note
  73 //!
  74 //! If constructing an [`Offer`] for use with a [`ChannelManager`], use
  75 //! [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
  76 //!
  77 //! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  78 //! [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
  79
  80 use bitcoin::blockdata::constants::ChainHash;
  81 use bitcoin::network::Network;
  82 use bitcoin::secp256k1::{Keypair, PublicKey, Secp256k1, self};
  83 use core::hash::{Hash, Hasher};
  84 use core::num::NonZeroU64;
  85 use core::ops::Deref;
  86 use core::str::FromStr;
  87 use core::time::Duration;
  88 use crate::sign::EntropySource;
  89 use crate::io;
  90 use crate::blinded_path::BlindedPath;
  91 use crate::ln::channelmanager::PaymentId;
  92 use crate::ln::features::OfferFeatures;
  93 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  94 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
  95 use crate::offers::merkle::{TaggedHash, TlvStream};
  96 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
  97 use crate::offers::signer::{Metadata, MetadataMaterial, self};
  98 use crate::util::ser::{HighZeroBytesDroppedBigSize, Readable, WithoutLength, Writeable, Writer};
  99 use crate::util::string::PrintableString;
 100
 101 #[cfg(not(c_bindings))]
 102 use {
 103         crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder},
 104 };
 105 #[cfg(c_bindings)]
 106 use {
 107         crate::offers::invoice_request::{InvoiceRequestWithDerivedPayerIdBuilder, InvoiceRequestWithExplicitPayerIdBuilder},
 108 };
 109
 110 #[allow(unused_imports)]
 111 use crate::prelude::*;
 112
 113 #[cfg(feature = "std")]
 114 use std::time::SystemTime;
 115
 116 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
 117
 118 /// An identifier for an [`Offer`] built using [`DerivedMetadata`].
 119 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 120 pub struct OfferId(pub [u8; 32]);
 121
 122 impl OfferId {
 123         const ID_TAG: &'static str = "LDK Offer ID";
 124
 125         fn from_valid_offer_tlv_stream(bytes: &[u8]) -> Self {
 126                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(Self::ID_TAG, bytes);
 127                 Self(tagged_hash.to_bytes())
 128         }
 129
 130         fn from_valid_invreq_tlv_stream(bytes: &[u8]) -> Self {
 131                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES);
 132                 let tagged_hash = TaggedHash::from_tlv_stream(Self::ID_TAG, tlv_stream);
 133                 Self(tagged_hash.to_bytes())
 134         }
 135 }
 136
 137 impl Writeable for OfferId {
 138         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 139                 self.0.write(w)
 140         }
 141 }
 142
 143 impl Readable for OfferId {
 144         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
 145                 Ok(OfferId(Readable::read(r)?))
 146         }
 147 }
 148
 149 /// Builds an [`Offer`] for the "offer to be paid" flow.
 150 ///
 151 /// See [module-level documentation] for usage.
 152 ///
 153 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 154 ///
 155 /// [module-level documentation]: self
 156 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
 157         offer: OfferContents,
 158         metadata_strategy: core::marker::PhantomData<M>,
 159         secp_ctx: Option<&'a Secp256k1<T>>,
 160 }
 161
 162 /// Builds an [`Offer`] for the "offer to be paid" flow.
 163 ///
 164 /// See [module-level documentation] for usage.
 165 ///
 166 /// [module-level documentation]: self
 167 #[cfg(c_bindings)]
 168 #[derive(Clone)]
 169 pub struct OfferWithExplicitMetadataBuilder<'a> {
 170         offer: OfferContents,
 171         metadata_strategy: core::marker::PhantomData<ExplicitMetadata>,
 172         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 173 }
 174
 175 /// Builds an [`Offer`] for the "offer to be paid" flow.
 176 ///
 177 /// See [module-level documentation] for usage.
 178 ///
 179 /// [module-level documentation]: self
 180 #[cfg(c_bindings)]
 181 #[derive(Clone)]
 182 pub struct OfferWithDerivedMetadataBuilder<'a> {
 183         offer: OfferContents,
 184         metadata_strategy: core::marker::PhantomData<DerivedMetadata>,
 185         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 186 }
 187
 188 /// Indicates how [`Offer::metadata`] may be set.
 189 ///
 190 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 191 pub trait MetadataStrategy {}
 192
 193 /// [`Offer::metadata`] may be explicitly set or left empty.
 194 ///
 195 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 196 pub struct ExplicitMetadata {}
 197
 198 /// [`Offer::metadata`] will be derived.
 199 ///
 200 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 201 pub struct DerivedMetadata {}
 202
 203 impl MetadataStrategy for ExplicitMetadata {}
 204
 205 impl MetadataStrategy for DerivedMetadata {}
 206
 207 macro_rules! offer_explicit_metadata_builder_methods { (
 208         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr
 209 ) => {
 210         /// Creates a new builder for an offer using the [`Offer::signing_pubkey`] for signing invoices.
 211         /// The associated secret key must be remembered while the offer is valid.
 212         ///
 213         /// Use a different pubkey per offer to avoid correlating offers.
 214         ///
 215         /// # Note
 216         ///
 217         /// If constructing an [`Offer`] for use with a [`ChannelManager`], use
 218         /// [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
 219         ///
 220         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 221         /// [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
 222         pub fn new(signing_pubkey: PublicKey) -> Self {
 223                 Self {
 224                         offer: OfferContents {
 225                                 chains: None, metadata: None, amount: None, description: None,
 226                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 227                                 supported_quantity: Quantity::One, signing_pubkey: Some(signing_pubkey),
 228                         },
 229                         metadata_strategy: core::marker::PhantomData,
 230                         secp_ctx: None,
 231                 }
 232         }
 233
 234         /// Sets the [`Offer::metadata`] to the given bytes.
 235         ///
 236         /// Successive calls to this method will override the previous setting.
 237         pub fn metadata(mut $self: $self_type, metadata: Vec<u8>) -> Result<$return_type, Bolt12SemanticError> {
 238                 $self.offer.metadata = Some(Metadata::Bytes(metadata));
 239                 Ok($return_value)
 240         }
 241 } }
 242
 243 macro_rules! offer_derived_metadata_builder_methods { ($secp_context: ty) => {
 244         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
 245         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
 246         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
 247         /// provided `node_id` is used for the signing pubkey.
 248         ///
 249         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
 250         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
 251         /// [`ExpandedKey`].
 252         ///
 253         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
 254         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 255         pub fn deriving_signing_pubkey<ES: Deref>(
 256                 node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 257                 secp_ctx: &'a Secp256k1<$secp_context>
 258         ) -> Self where ES::Target: EntropySource {
 259                 let nonce = Nonce::from_entropy_source(entropy_source);
 260                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
 261                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 262                 Self {
 263                         offer: OfferContents {
 264                                 chains: None, metadata: Some(metadata), amount: None, description: None,
 265                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 266                                 supported_quantity: Quantity::One, signing_pubkey: Some(node_id),
 267                         },
 268                         metadata_strategy: core::marker::PhantomData,
 269                         secp_ctx: Some(secp_ctx),
 270                 }
 271         }
 272 } }
 273
 274 macro_rules! offer_builder_methods { (
 275         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 276 ) => {
 277         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 278         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 279         ///
 280         /// See [`Offer::chains`] on how this relates to the payment currency.
 281         ///
 282         /// Successive calls to this method will add another chain hash.
 283         pub fn chain($self: $self_type, network: Network) -> $return_type {
 284                 $self.chain_hash(ChainHash::using_genesis_block(network))
 285         }
 286
 287         /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
 288         /// [`Network::Bitcoin`] is assumed to be the only one supported.
 289         ///
 290         /// See [`Offer::chains`] on how this relates to the payment currency.
 291         ///
 292         /// Successive calls to this method will add another chain hash.
 293         pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> $return_type {
 294                 let chains = $self.offer.chains.get_or_insert_with(Vec::new);
 295                 if !chains.contains(&chain) {
 296                         chains.push(chain);
 297                 }
 298
 299                 $return_value
 300         }
 301
 302         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 303         ///
 304         /// Successive calls to this method will override the previous setting.
 305         pub fn amount_msats($self: $self_type, amount_msats: u64) -> $return_type {
 306                 $self.amount(Amount::Bitcoin { amount_msats })
 307         }
 308
 309         /// Sets the [`Offer::amount`].
 310         ///
 311         /// Successive calls to this method will override the previous setting.
 312         pub(super) fn amount($($self_mut)* $self: $self_type, amount: Amount) -> $return_type {
 313                 $self.offer.amount = Some(amount);
 314                 $return_value
 315         }
 316
 317         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 318         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 319         ///
 320         /// Successive calls to this method will override the previous setting.
 321         pub fn absolute_expiry($($self_mut)* $self: $self_type, absolute_expiry: Duration) -> $return_type {
 322                 $self.offer.absolute_expiry = Some(absolute_expiry);
 323                 $return_value
 324         }
 325
 326         /// Sets the [`Offer::description`].
 327         ///
 328         /// Successive calls to this method will override the previous setting.
 329         pub fn description($($self_mut)* $self: $self_type, description: String) -> $return_type {
 330                 $self.offer.description = Some(description);
 331                 $return_value
 332         }
 333
 334         /// Sets the [`Offer::issuer`].
 335         ///
 336         /// Successive calls to this method will override the previous setting.
 337         pub fn issuer($($self_mut)* $self: $self_type, issuer: String) -> $return_type {
 338                 $self.offer.issuer = Some(issuer);
 339                 $return_value
 340         }
 341
 342         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 343         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 344         ///
 345         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 346         /// adding duplicate paths.
 347         pub fn path($($self_mut)* $self: $self_type, path: BlindedPath) -> $return_type {
 348                 $self.offer.paths.get_or_insert_with(Vec::new).push(path);
 349                 $return_value
 350         }
 351
 352         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 353         /// [`Quantity::One`].
 354         ///
 355         /// Successive calls to this method will override the previous setting.
 356         pub fn supported_quantity($($self_mut)* $self: $self_type, quantity: Quantity) -> $return_type {
 357                 $self.offer.supported_quantity = quantity;
 358                 $return_value
 359         }
 360
 361         /// Builds an [`Offer`] from the builder's settings.
 362         pub fn build($($self_mut)* $self: $self_type) -> Result<Offer, Bolt12SemanticError> {
 363                 match $self.offer.amount {
 364                         Some(Amount::Bitcoin { amount_msats }) => {
 365                                 if amount_msats > MAX_VALUE_MSAT {
 366                                         return Err(Bolt12SemanticError::InvalidAmount);
 367                                 }
 368                         },
 369                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 370                         None => {},
 371                 }
 372
 373                 if $self.offer.amount.is_some() && $self.offer.description.is_none() {
 374                         $self.offer.description = Some(String::new());
 375                 }
 376
 377                 if let Some(chains) = &$self.offer.chains {
 378                         if chains.len() == 1 && chains[0] == $self.offer.implied_chain() {
 379                                 $self.offer.chains = None;
 380                         }
 381                 }
 382
 383                 Ok($self.build_without_checks())
 384         }
 385
 386         fn build_without_checks($($self_mut)* $self: $self_type) -> Offer {
 387                 // Create the metadata for stateless verification of an InvoiceRequest.
 388                 if let Some(mut metadata) = $self.offer.metadata.take() {
 389                         if metadata.has_derivation_material() {
 390                                 if $self.offer.paths.is_none() {
 391                                         metadata = metadata.without_keys();
 392                                 }
 393
 394                                 let mut tlv_stream = $self.offer.as_tlv_stream();
 395                                 debug_assert_eq!(tlv_stream.metadata, None);
 396                                 tlv_stream.metadata = None;
 397                                 if metadata.derives_recipient_keys() {
 398                                         tlv_stream.node_id = None;
 399                                 }
 400
 401                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
 402                                 metadata = derived_metadata;
 403                                 if let Some(keys) = keys {
 404                                         $self.offer.signing_pubkey = Some(keys.public_key());
 405                                 }
 406                         }
 407
 408                         $self.offer.metadata = Some(metadata);
 409                 }
 410
 411                 let mut bytes = Vec::new();
 412                 $self.offer.write(&mut bytes).unwrap();
 413
 414                 let id = OfferId::from_valid_offer_tlv_stream(&bytes);
 415
 416                 Offer {
 417                         bytes,
 418                         #[cfg(not(c_bindings))]
 419                         contents: $self.offer,
 420                         #[cfg(c_bindings)]
 421                         contents: $self.offer.clone(),
 422                         id,
 423                 }
 424         }
 425 } }
 426
 427 #[cfg(test)]
 428 macro_rules! offer_builder_test_methods { (
 429         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 430 ) => {
 431         #[cfg_attr(c_bindings, allow(dead_code))]
 432         fn features_unchecked($($self_mut)* $self: $self_type, features: OfferFeatures) -> $return_type {
 433                 $self.offer.features = features;
 434                 $return_value
 435         }
 436
 437         #[cfg_attr(c_bindings, allow(dead_code))]
 438         pub(crate) fn clear_chains($($self_mut)* $self: $self_type) -> $return_type {
 439                 $self.offer.chains = None;
 440                 $return_value
 441         }
 442
 443         #[cfg_attr(c_bindings, allow(dead_code))]
 444         pub(crate) fn clear_paths($($self_mut)* $self: $self_type) -> $return_type {
 445                 $self.offer.paths = None;
 446                 $return_value
 447         }
 448
 449         #[cfg_attr(c_bindings, allow(dead_code))]
 450         pub(crate) fn clear_signing_pubkey($($self_mut)* $self: $self_type) -> $return_type {
 451                 $self.offer.signing_pubkey = None;
 452                 $return_value
 453         }
 454
 455         #[cfg_attr(c_bindings, allow(dead_code))]
 456         pub(super) fn build_unchecked($self: $self_type) -> Offer {
 457                 $self.build_without_checks()
 458         }
 459 } }
 460
 461 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 462         offer_builder_methods!(self, Self, Self, self, mut);
 463
 464         #[cfg(test)]
 465         offer_builder_test_methods!(self, Self, Self, self, mut);
 466 }
 467
 468 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
 469         offer_explicit_metadata_builder_methods!(self, Self, Self, self);
 470 }
 471
 472 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
 473         offer_derived_metadata_builder_methods!(T);
 474 }
 475
 476 #[cfg(all(c_bindings, not(test)))]
 477 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 478         offer_explicit_metadata_builder_methods!(self, &mut Self, (), ());
 479         offer_builder_methods!(self, &mut Self, (), ());
 480 }
 481
 482 #[cfg(all(c_bindings, test))]
 483 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 484         offer_explicit_metadata_builder_methods!(self, &mut Self, &mut Self, self);
 485         offer_builder_methods!(self, &mut Self, &mut Self, self);
 486         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 487 }
 488
 489 #[cfg(all(c_bindings, not(test)))]
 490 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 491         offer_derived_metadata_builder_methods!(secp256k1::All);
 492         offer_builder_methods!(self, &mut Self, (), ());
 493 }
 494
 495 #[cfg(all(c_bindings, test))]
 496 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 497         offer_derived_metadata_builder_methods!(secp256k1::All);
 498         offer_builder_methods!(self, &mut Self, &mut Self, self);
 499         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 500 }
 501
 502 #[cfg(c_bindings)]
 503 impl<'a> From<OfferBuilder<'a, DerivedMetadata, secp256k1::All>>
 504 for OfferWithDerivedMetadataBuilder<'a> {
 505         fn from(builder: OfferBuilder<'a, DerivedMetadata, secp256k1::All>) -> Self {
 506                 let OfferBuilder { offer, metadata_strategy, secp_ctx } = builder;
 507
 508                 Self { offer, metadata_strategy, secp_ctx }
 509         }
 510 }
 511
 512 #[cfg(c_bindings)]
 513 impl<'a> From<OfferWithDerivedMetadataBuilder<'a>>
 514 for OfferBuilder<'a, DerivedMetadata, secp256k1::All> {
 515         fn from(builder: OfferWithDerivedMetadataBuilder<'a>) -> Self {
 516                 let OfferWithDerivedMetadataBuilder { offer, metadata_strategy, secp_ctx } = builder;
 517
 518                 Self { offer, metadata_strategy, secp_ctx }
 519         }
 520 }
 521
 522 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 523 ///
 524 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 525 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 526 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 527 ///
 528 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 529 /// latter.
 530 ///
 531 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 532 ///
 533 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 534 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 535 #[derive(Clone, Debug)]
 536 pub struct Offer {
 537         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 538         // fields.
 539         pub(super) bytes: Vec<u8>,
 540         pub(super) contents: OfferContents,
 541         id: OfferId,
 542 }
 543
 544 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 545 /// [`Bolt12Invoice`].
 546 ///
 547 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 548 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 549 #[derive(Clone, Debug)]
 550 #[cfg_attr(test, derive(PartialEq))]
 551 pub(super) struct OfferContents {
 552         chains: Option<Vec<ChainHash>>,
 553         metadata: Option<Metadata>,
 554         amount: Option<Amount>,
 555         description: Option<String>,
 556         features: OfferFeatures,
 557         absolute_expiry: Option<Duration>,
 558         issuer: Option<String>,
 559         paths: Option<Vec<BlindedPath>>,
 560         supported_quantity: Quantity,
 561         signing_pubkey: Option<PublicKey>,
 562 }
 563
 564 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 565         // TODO: Return a slice once ChainHash has constants.
 566         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 567         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 568         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 569         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 570         /// for the selected chain.
 571         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 572                 $contents.chains()
 573         }
 574
 575         // TODO: Link to corresponding method in `InvoiceRequest`.
 576         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 577         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 578         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 579                 $contents.metadata()
 580         }
 581
 582         /// The minimum amount required for a successful payment of a single item.
 583         pub fn amount(&$self) -> Option<$crate::offers::offer::Amount> {
 584                 $contents.amount()
 585         }
 586
 587         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 588         /// but with the caveat that it has not been verified in any way.
 589         pub fn description(&$self) -> Option<$crate::util::string::PrintableString> {
 590                 $contents.description()
 591         }
 592
 593         /// Features pertaining to the offer.
 594         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 595                 &$contents.features()
 596         }
 597
 598         /// Duration since the Unix epoch when an invoice should no longer be requested.
 599         ///
 600         /// If `None`, the offer does not expire.
 601         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 602                 $contents.absolute_expiry()
 603         }
 604
 605         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 606         /// displayed to the user but with the caveat that it has not been verified in any way.
 607         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 608                 $contents.issuer()
 609         }
 610
 611         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 612         /// recipient privacy by obfuscating its node id.
 613         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 614                 $contents.paths()
 615         }
 616
 617         /// The quantity of items supported.
 618         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 619                 $contents.supported_quantity()
 620         }
 621
 622         /// The public key used by the recipient to sign invoices.
 623         pub fn signing_pubkey(&$self) -> Option<bitcoin::secp256k1::PublicKey> {
 624                 $contents.signing_pubkey()
 625         }
 626 } }
 627
 628 impl Offer {
 629         offer_accessors!(self, self.contents);
 630
 631         /// Returns the id of the offer.
 632         pub fn id(&self) -> OfferId {
 633                 self.id
 634         }
 635
 636         pub(super) fn implied_chain(&self) -> ChainHash {
 637                 self.contents.implied_chain()
 638         }
 639
 640         /// Returns whether the given chain is supported by the offer.
 641         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 642                 self.contents.supports_chain(chain)
 643         }
 644
 645         /// Whether the offer has expired.
 646         #[cfg(feature = "std")]
 647         pub fn is_expired(&self) -> bool {
 648                 self.contents.is_expired()
 649         }
 650
 651         /// Whether the offer has expired given the duration since the Unix epoch.
 652         pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 653                 self.contents.is_expired_no_std(duration_since_epoch)
 654         }
 655
 656         /// Returns whether the given quantity is valid for the offer.
 657         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 658                 self.contents.is_valid_quantity(quantity)
 659         }
 660
 661         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 662         ///
 663         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 664         pub fn expects_quantity(&self) -> bool {
 665                 self.contents.expects_quantity()
 666         }
 667
 668         #[cfg(async_payments)]
 669         pub(super) fn verify<T: secp256k1::Signing>(
 670                 &self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 671         ) -> Result<(OfferId, Option<Keypair>), ()> {
 672                 self.contents.verify(&self.bytes, key, secp_ctx)
 673         }
 674 }
 675
 676 macro_rules! request_invoice_derived_payer_id { ($self: ident, $builder: ty) => {
 677         /// Similar to [`Offer::request_invoice`] except it:
 678         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 679         ///   request,
 680         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 681         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 682         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 683         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 684         ///   be used when sending the payment for the requested invoice.
 685         ///
 686         /// Useful to protect the sender's privacy.
 687         ///
 688         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 689         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 690         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 691         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 692         pub fn request_invoice_deriving_payer_id<
 693                 'a, 'b, ES: Deref,
 694                 #[cfg(not(c_bindings))]
 695                 T: secp256k1::Signing
 696         >(
 697                 &'a $self, expanded_key: &ExpandedKey, entropy_source: ES,
 698                 #[cfg(not(c_bindings))]
 699                 secp_ctx: &'b Secp256k1<T>,
 700                 #[cfg(c_bindings)]
 701                 secp_ctx: &'b Secp256k1<secp256k1::All>,
 702                 payment_id: PaymentId
 703         ) -> Result<$builder, Bolt12SemanticError>
 704         where
 705                 ES::Target: EntropySource,
 706         {
 707                 if $self.offer_features().requires_unknown_bits() {
 708                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 709                 }
 710
 711                 Ok(<$builder>::deriving_payer_id($self, expanded_key, entropy_source, secp_ctx, payment_id))
 712         }
 713 } }
 714
 715 macro_rules! request_invoice_explicit_payer_id { ($self: ident, $builder: ty) => {
 716         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 717         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 718         ///
 719         /// Useful for recurring payments using the same `payer_id` with different invoices.
 720         ///
 721         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 722         pub fn request_invoice_deriving_metadata<ES: Deref>(
 723                 &$self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 724                 payment_id: PaymentId
 725         ) -> Result<$builder, Bolt12SemanticError>
 726         where
 727                 ES::Target: EntropySource,
 728         {
 729                 if $self.offer_features().requires_unknown_bits() {
 730                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 731                 }
 732
 733                 Ok(<$builder>::deriving_metadata($self, payer_id, expanded_key, entropy_source, payment_id))
 734         }
 735
 736         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 737         /// which will be reflected in the `Bolt12Invoice` response.
 738         ///
 739         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 740         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 741         /// hashing in the signature calculation.
 742         ///
 743         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 744         /// Otherwise, payments may be correlated.
 745         ///
 746         /// Errors if the offer contains unknown required features.
 747         ///
 748         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 749         pub fn request_invoice(
 750                 &$self, metadata: Vec<u8>, payer_id: PublicKey
 751         ) -> Result<$builder, Bolt12SemanticError> {
 752                 if $self.offer_features().requires_unknown_bits() {
 753                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 754                 }
 755
 756                 Ok(<$builder>::new($self, metadata, payer_id))
 757         }
 758 } }
 759
 760 #[cfg(not(c_bindings))]
 761 impl Offer {
 762         request_invoice_derived_payer_id!(self, InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>);
 763         request_invoice_explicit_payer_id!(self, InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>);
 764 }
 765
 766 #[cfg(c_bindings)]
 767 impl Offer {
 768         request_invoice_derived_payer_id!(self, InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>);
 769         request_invoice_explicit_payer_id!(self, InvoiceRequestWithExplicitPayerIdBuilder);
 770 }
 771
 772 #[cfg(test)]
 773 impl Offer {
 774         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 775                 self.contents.as_tlv_stream()
 776         }
 777 }
 778
 779 impl AsRef<[u8]> for Offer {
 780         fn as_ref(&self) -> &[u8] {
 781                 &self.bytes
 782         }
 783 }
 784
 785 impl PartialEq for Offer {
 786         fn eq(&self, other: &Self) -> bool {
 787                 self.bytes.eq(&other.bytes)
 788         }
 789 }
 790
 791 impl Eq for Offer {}
 792
 793 impl Hash for Offer {
 794         fn hash<H: Hasher>(&self, state: &mut H) {
 795                 self.bytes.hash(state);
 796         }
 797 }
 798
 799 impl OfferContents {
 800         pub fn chains(&self) -> Vec<ChainHash> {
 801                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 802         }
 803
 804         pub fn implied_chain(&self) -> ChainHash {
 805                 ChainHash::using_genesis_block(Network::Bitcoin)
 806         }
 807
 808         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 809                 self.chains().contains(&chain)
 810         }
 811
 812         pub fn metadata(&self) -> Option<&Vec<u8>> {
 813                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 814         }
 815
 816         pub fn amount(&self) -> Option<Amount> {
 817                 self.amount
 818         }
 819
 820         pub fn description(&self) -> Option<PrintableString> {
 821                 self.description.as_ref().map(|description| PrintableString(description))
 822         }
 823
 824         pub fn features(&self) -> &OfferFeatures {
 825                 &self.features
 826         }
 827
 828         pub fn absolute_expiry(&self) -> Option<Duration> {
 829                 self.absolute_expiry
 830         }
 831
 832         #[cfg(feature = "std")]
 833         pub(super) fn is_expired(&self) -> bool {
 834                 SystemTime::UNIX_EPOCH
 835                         .elapsed()
 836                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 837                         .unwrap_or(false)
 838         }
 839
 840         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 841                 self.absolute_expiry
 842                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 843                         .unwrap_or(false)
 844         }
 845
 846         pub fn issuer(&self) -> Option<PrintableString> {
 847                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 848         }
 849
 850         pub fn paths(&self) -> &[BlindedPath] {
 851                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 852         }
 853
 854         pub(super) fn check_amount_msats_for_quantity(
 855                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 856         ) -> Result<(), Bolt12SemanticError> {
 857                 let offer_amount_msats = match self.amount {
 858                         None => 0,
 859                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 860                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 861                 };
 862
 863                 if !self.expects_quantity() || quantity.is_some() {
 864                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 865                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 866                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 867
 868                         if amount_msats < expected_amount_msats {
 869                                 return Err(Bolt12SemanticError::InsufficientAmount);
 870                         }
 871
 872                         if amount_msats > MAX_VALUE_MSAT {
 873                                 return Err(Bolt12SemanticError::InvalidAmount);
 874                         }
 875                 }
 876
 877                 Ok(())
 878         }
 879
 880         pub fn supported_quantity(&self) -> Quantity {
 881                 self.supported_quantity
 882         }
 883
 884         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 885                 let expects_quantity = self.expects_quantity();
 886                 match quantity {
 887                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 888                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 889                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 890                                 Err(Bolt12SemanticError::InvalidQuantity)
 891                         },
 892                         _ => Ok(()),
 893                 }
 894         }
 895
 896         fn is_valid_quantity(&self, quantity: u64) -> bool {
 897                 match self.supported_quantity {
 898                         Quantity::Bounded(n) => quantity <= n.get(),
 899                         Quantity::Unbounded => quantity > 0,
 900                         Quantity::One => quantity == 1,
 901                 }
 902         }
 903
 904         fn expects_quantity(&self) -> bool {
 905                 match self.supported_quantity {
 906                         Quantity::Bounded(_) => true,
 907                         Quantity::Unbounded => true,
 908                         Quantity::One => false,
 909                 }
 910         }
 911
 912         pub(super) fn signing_pubkey(&self) -> Option<PublicKey> {
 913                 self.signing_pubkey
 914         }
 915
 916         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 917         pub(super) fn verify<T: secp256k1::Signing>(
 918                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 919         ) -> Result<(OfferId, Option<Keypair>), ()> {
 920                 match self.metadata() {
 921                         Some(metadata) => {
 922                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 923                                         match record.r#type {
 924                                                 OFFER_METADATA_TYPE => false,
 925                                                 OFFER_NODE_ID_TYPE => {
 926                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 927                                                 },
 928                                                 _ => true,
 929                                         }
 930                                 });
 931                                 let signing_pubkey = match self.signing_pubkey() {
 932                                         Some(signing_pubkey) => signing_pubkey,
 933                                         None => return Err(()),
 934                                 };
 935                                 let keys = signer::verify_recipient_metadata(
 936                                         metadata, key, IV_BYTES, signing_pubkey, tlv_stream, secp_ctx
 937                                 )?;
 938
 939                                 let offer_id = OfferId::from_valid_invreq_tlv_stream(bytes);
 940
 941                                 Ok((offer_id, keys))
 942                         },
 943                         None => Err(()),
 944                 }
 945         }
 946
 947         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 948                 let (currency, amount) = match &self.amount {
 949                         None => (None, None),
 950                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 951                         Some(Amount::Currency { iso4217_code, amount }) => (
 952                                 Some(iso4217_code), Some(*amount)
 953                         ),
 954                 };
 955
 956                 let features = {
 957                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 958                 };
 959
 960                 OfferTlvStreamRef {
 961                         chains: self.chains.as_ref(),
 962                         metadata: self.metadata(),
 963                         currency,
 964                         amount,
 965                         description: self.description.as_ref(),
 966                         features,
 967                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 968                         paths: self.paths.as_ref(),
 969                         issuer: self.issuer.as_ref(),
 970                         quantity_max: self.supported_quantity.to_tlv_record(),
 971                         node_id: self.signing_pubkey.as_ref(),
 972                 }
 973         }
 974 }
 975
 976 impl Readable for Offer {
 977         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 978                 let bytes: WithoutLength<Vec<u8>> = Readable::read(reader)?;
 979                 Self::try_from(bytes.0).map_err(|_| DecodeError::InvalidValue)
 980         }
 981 }
 982
 983 impl Writeable for Offer {
 984         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 985                 WithoutLength(&self.bytes).write(writer)
 986         }
 987 }
 988
 989 impl Writeable for OfferContents {
 990         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 991                 self.as_tlv_stream().write(writer)
 992         }
 993 }
 994
 995 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 996 /// another currency.
 997 #[derive(Clone, Copy, Debug, PartialEq)]
 998 pub enum Amount {
 999         /// An amount of bitcoin.
1000         Bitcoin {
1001                 /// The amount in millisatoshi.
1002                 amount_msats: u64,
1003         },
1004         /// An amount of currency specified using ISO 4712.
1005         Currency {
1006                 /// The currency that the amount is denominated in.
1007                 iso4217_code: CurrencyCode,
1008                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
1009                 amount: u64,
1010         },
1011 }
1012
1013 /// An ISO 4712 three-letter currency code (e.g., USD).
1014 pub type CurrencyCode = [u8; 3];
1015
1016 /// Quantity of items supported by an [`Offer`].
1017 #[derive(Clone, Copy, Debug, PartialEq)]
1018 pub enum Quantity {
1019         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
1020         /// but is limited (e.g., because of per customer or inventory limits).
1021         ///
1022         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
1023         /// is supported.
1024         Bounded(NonZeroU64),
1025         /// One or more items. Use when more than one item can be requested without any limit.
1026         Unbounded,
1027         /// Only one item. Use when only a single item can be requested.
1028         One,
1029 }
1030
1031 impl Quantity {
1032         fn to_tlv_record(&self) -> Option<u64> {
1033                 match self {
1034                         Quantity::Bounded(n) => Some(n.get()),
1035                         Quantity::Unbounded => Some(0),
1036                         Quantity::One => None,
1037                 }
1038         }
1039 }
1040
1041 /// Valid type range for offer TLV records.
1042 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
1043
1044 /// TLV record type for [`Offer::metadata`].
1045 const OFFER_METADATA_TYPE: u64 = 4;
1046
1047 /// TLV record type for [`Offer::signing_pubkey`].
1048 const OFFER_NODE_ID_TYPE: u64 = 22;
1049
1050 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
1051         (2, chains: (Vec<ChainHash>, WithoutLength)),
1052         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
1053         (6, currency: CurrencyCode),
1054         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
1055         (10, description: (String, WithoutLength)),
1056         (12, features: (OfferFeatures, WithoutLength)),
1057         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
1058         (16, paths: (Vec<BlindedPath>, WithoutLength)),
1059         (18, issuer: (String, WithoutLength)),
1060         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
1061         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
1062 });
1063
1064 impl Bech32Encode for Offer {
1065         const BECH32_HRP: &'static str = "lno";
1066 }
1067
1068 impl FromStr for Offer {
1069         type Err = Bolt12ParseError;
1070
1071         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
1072                 Self::from_bech32_str(s)
1073         }
1074 }
1075
1076 impl TryFrom<Vec<u8>> for Offer {
1077         type Error = Bolt12ParseError;
1078
1079         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1080                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
1081                 let ParsedMessage { bytes, tlv_stream } = offer;
1082                 let contents = OfferContents::try_from(tlv_stream)?;
1083                 let id = OfferId::from_valid_offer_tlv_stream(&bytes);
1084
1085                 Ok(Offer { bytes, contents, id })
1086         }
1087 }
1088
1089 impl TryFrom<OfferTlvStream> for OfferContents {
1090         type Error = Bolt12SemanticError;
1091
1092         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
1093                 let OfferTlvStream {
1094                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
1095                         issuer, quantity_max, node_id,
1096                 } = tlv_stream;
1097
1098                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
1099
1100                 let amount = match (currency, amount) {
1101                         (None, None) => None,
1102                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
1103                                 return Err(Bolt12SemanticError::InvalidAmount);
1104                         },
1105                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
1106                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
1107                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
1108                 };
1109
1110                 if amount.is_some() && description.is_none() {
1111                         return Err(Bolt12SemanticError::MissingDescription);
1112                 }
1113
1114                 let features = features.unwrap_or_else(OfferFeatures::empty);
1115
1116                 let absolute_expiry = absolute_expiry
1117                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
1118
1119                 let supported_quantity = match quantity_max {
1120                         None => Quantity::One,
1121                         Some(0) => Quantity::Unbounded,
1122                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
1123                 };
1124
1125                 let (signing_pubkey, paths) = match (node_id, paths) {
1126                         (None, None) => return Err(Bolt12SemanticError::MissingSigningPubkey),
1127                         (_, Some(paths)) if paths.is_empty() => return Err(Bolt12SemanticError::MissingPaths),
1128                         (node_id, paths) => (node_id, paths),
1129                 };
1130
1131                 Ok(OfferContents {
1132                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
1133                         supported_quantity, signing_pubkey,
1134                 })
1135         }
1136 }
1137
1138 impl core::fmt::Display for Offer {
1139         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1140                 self.fmt_bech32_str(f)
1141         }
1142 }
1143
1144 #[cfg(test)]
1145 mod tests {
1146         use super::{Amount, Offer, OfferTlvStreamRef, Quantity};
1147         #[cfg(not(c_bindings))]
1148         use {
1149                 super::OfferBuilder,
1150         };
1151         #[cfg(c_bindings)]
1152         use {
1153                 super::OfferWithExplicitMetadataBuilder as OfferBuilder,
1154         };
1155
1156         use bitcoin::blockdata::constants::ChainHash;
1157         use bitcoin::network::Network;
1158         use bitcoin::secp256k1::Secp256k1;
1159         use core::num::NonZeroU64;
1160         use core::time::Duration;
1161         use crate::blinded_path::{BlindedHop, BlindedPath, IntroductionNode};
1162         use crate::sign::KeyMaterial;
1163         use crate::ln::features::OfferFeatures;
1164         use crate::ln::inbound_payment::ExpandedKey;
1165         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1166         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1167         use crate::offers::test_utils::*;
1168         use crate::util::ser::{BigSize, Writeable};
1169         use crate::util::string::PrintableString;
1170
1171         #[test]
1172         fn builds_offer_with_defaults() {
1173                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1174
1175                 let mut buffer = Vec::new();
1176                 offer.write(&mut buffer).unwrap();
1177
1178                 assert_eq!(offer.bytes, buffer.as_slice());
1179                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1180                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
1181                 assert_eq!(offer.metadata(), None);
1182                 assert_eq!(offer.amount(), None);
1183                 assert_eq!(offer.description(), None);
1184                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1185                 assert_eq!(offer.absolute_expiry(), None);
1186                 #[cfg(feature = "std")]
1187                 assert!(!offer.is_expired());
1188                 assert_eq!(offer.paths(), &[]);
1189                 assert_eq!(offer.issuer(), None);
1190                 assert_eq!(offer.supported_quantity(), Quantity::One);
1191                 assert!(!offer.expects_quantity());
1192                 assert_eq!(offer.signing_pubkey(), Some(pubkey(42)));
1193
1194                 assert_eq!(
1195                         offer.as_tlv_stream(),
1196                         OfferTlvStreamRef {
1197                                 chains: None,
1198                                 metadata: None,
1199                                 currency: None,
1200                                 amount: None,
1201                                 description: None,
1202                                 features: None,
1203                                 absolute_expiry: None,
1204                                 paths: None,
1205                                 issuer: None,
1206                                 quantity_max: None,
1207                                 node_id: Some(&pubkey(42)),
1208                         },
1209                 );
1210
1211                 if let Err(e) = Offer::try_from(buffer) {
1212                         panic!("error parsing offer: {:?}", e);
1213                 }
1214         }
1215
1216         #[test]
1217         fn builds_offer_with_chains() {
1218                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1219                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1220
1221                 let offer = OfferBuilder::new(pubkey(42))
1222                         .chain(Network::Bitcoin)
1223                         .build()
1224                         .unwrap();
1225                 assert!(offer.supports_chain(mainnet));
1226                 assert_eq!(offer.chains(), vec![mainnet]);
1227                 assert_eq!(offer.as_tlv_stream().chains, None);
1228
1229                 let offer = OfferBuilder::new(pubkey(42))
1230                         .chain(Network::Testnet)
1231                         .build()
1232                         .unwrap();
1233                 assert!(offer.supports_chain(testnet));
1234                 assert_eq!(offer.chains(), vec![testnet]);
1235                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1236
1237                 let offer = OfferBuilder::new(pubkey(42))
1238                         .chain(Network::Testnet)
1239                         .chain(Network::Testnet)
1240                         .build()
1241                         .unwrap();
1242                 assert!(offer.supports_chain(testnet));
1243                 assert_eq!(offer.chains(), vec![testnet]);
1244                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1245
1246                 let offer = OfferBuilder::new(pubkey(42))
1247                         .chain(Network::Bitcoin)
1248                         .chain(Network::Testnet)
1249                         .build()
1250                         .unwrap();
1251                 assert!(offer.supports_chain(mainnet));
1252                 assert!(offer.supports_chain(testnet));
1253                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1254                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1255         }
1256
1257         #[test]
1258         fn builds_offer_with_metadata() {
1259                 let offer = OfferBuilder::new(pubkey(42))
1260                         .metadata(vec![42; 32]).unwrap()
1261                         .build()
1262                         .unwrap();
1263                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1264                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1265
1266                 let offer = OfferBuilder::new(pubkey(42))
1267                         .metadata(vec![42; 32]).unwrap()
1268                         .metadata(vec![43; 32]).unwrap()
1269                         .build()
1270                         .unwrap();
1271                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1272                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1273         }
1274
1275         #[test]
1276         fn builds_offer_with_metadata_derived() {
1277                 let node_id = recipient_pubkey();
1278                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1279                 let entropy = FixedEntropy {};
1280                 let secp_ctx = Secp256k1::new();
1281
1282                 #[cfg(c_bindings)]
1283                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1284                 let offer = OfferBuilder
1285                         ::deriving_signing_pubkey(node_id, &expanded_key, &entropy, &secp_ctx)
1286                         .amount_msats(1000)
1287                         .build().unwrap();
1288                 assert_eq!(offer.signing_pubkey(), Some(node_id));
1289
1290                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1291                         .build().unwrap()
1292                         .sign(payer_sign).unwrap();
1293                 match invoice_request.verify(&expanded_key, &secp_ctx) {
1294                         Ok(invoice_request) => assert_eq!(invoice_request.offer_id, offer.id()),
1295                         Err(_) => panic!("unexpected error"),
1296                 }
1297
1298                 // Fails verification with altered offer field
1299                 let mut tlv_stream = offer.as_tlv_stream();
1300                 tlv_stream.amount = Some(100);
1301
1302                 let mut encoded_offer = Vec::new();
1303                 tlv_stream.write(&mut encoded_offer).unwrap();
1304
1305                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1306                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1307                         .build().unwrap()
1308                         .sign(payer_sign).unwrap();
1309                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1310
1311                 // Fails verification with altered metadata
1312                 let mut tlv_stream = offer.as_tlv_stream();
1313                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1314                 tlv_stream.metadata = Some(&metadata);
1315
1316                 let mut encoded_offer = Vec::new();
1317                 tlv_stream.write(&mut encoded_offer).unwrap();
1318
1319                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1320                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1321                         .build().unwrap()
1322                         .sign(payer_sign).unwrap();
1323                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1324         }
1325
1326         #[test]
1327         fn builds_offer_with_derived_signing_pubkey() {
1328                 let node_id = recipient_pubkey();
1329                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1330                 let entropy = FixedEntropy {};
1331                 let secp_ctx = Secp256k1::new();
1332
1333                 let blinded_path = BlindedPath {
1334                         introduction_node: IntroductionNode::NodeId(pubkey(40)),
1335                         blinding_point: pubkey(41),
1336                         blinded_hops: vec![
1337                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1338                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1339                         ],
1340                 };
1341
1342                 #[cfg(c_bindings)]
1343                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1344                 let offer = OfferBuilder
1345                         ::deriving_signing_pubkey(node_id, &expanded_key, &entropy, &secp_ctx)
1346                         .amount_msats(1000)
1347                         .path(blinded_path)
1348                         .build().unwrap();
1349                 assert_ne!(offer.signing_pubkey(), Some(node_id));
1350
1351                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1352                         .build().unwrap()
1353                         .sign(payer_sign).unwrap();
1354                 match invoice_request.verify(&expanded_key, &secp_ctx) {
1355                         Ok(invoice_request) => assert_eq!(invoice_request.offer_id, offer.id()),
1356                         Err(_) => panic!("unexpected error"),
1357                 }
1358
1359                 // Fails verification with altered offer field
1360                 let mut tlv_stream = offer.as_tlv_stream();
1361                 tlv_stream.amount = Some(100);
1362
1363                 let mut encoded_offer = Vec::new();
1364                 tlv_stream.write(&mut encoded_offer).unwrap();
1365
1366                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1367                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1368                         .build().unwrap()
1369                         .sign(payer_sign).unwrap();
1370                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1371
1372                 // Fails verification with altered signing pubkey
1373                 let mut tlv_stream = offer.as_tlv_stream();
1374                 let signing_pubkey = pubkey(1);
1375                 tlv_stream.node_id = Some(&signing_pubkey);
1376
1377                 let mut encoded_offer = Vec::new();
1378                 tlv_stream.write(&mut encoded_offer).unwrap();
1379
1380                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1381                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1382                         .build().unwrap()
1383                         .sign(payer_sign).unwrap();
1384                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1385         }
1386
1387         #[test]
1388         fn builds_offer_with_amount() {
1389                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1390                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1391
1392                 let offer = OfferBuilder::new(pubkey(42))
1393                         .amount_msats(1000)
1394                         .build()
1395                         .unwrap();
1396                 let tlv_stream = offer.as_tlv_stream();
1397                 assert_eq!(offer.amount(), Some(bitcoin_amount));
1398                 assert_eq!(tlv_stream.amount, Some(1000));
1399                 assert_eq!(tlv_stream.currency, None);
1400
1401                 #[cfg(not(c_bindings))]
1402                 let builder = OfferBuilder::new(pubkey(42))
1403                         .amount(currency_amount.clone());
1404                 #[cfg(c_bindings)]
1405                 let mut builder = OfferBuilder::new(pubkey(42));
1406                 #[cfg(c_bindings)]
1407                 builder.amount(currency_amount.clone());
1408                 let tlv_stream = builder.offer.as_tlv_stream();
1409                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1410                 assert_eq!(tlv_stream.amount, Some(10));
1411                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1412                 match builder.build() {
1413                         Ok(_) => panic!("expected error"),
1414                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1415                 }
1416
1417                 let offer = OfferBuilder::new(pubkey(42))
1418                         .amount(currency_amount.clone())
1419                         .amount(bitcoin_amount.clone())
1420                         .build()
1421                         .unwrap();
1422                 let tlv_stream = offer.as_tlv_stream();
1423                 assert_eq!(tlv_stream.amount, Some(1000));
1424                 assert_eq!(tlv_stream.currency, None);
1425
1426                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1427                 match OfferBuilder::new(pubkey(42)).amount(invalid_amount).build() {
1428                         Ok(_) => panic!("expected error"),
1429                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1430                 }
1431         }
1432
1433         #[test]
1434         fn builds_offer_with_description() {
1435                 let offer = OfferBuilder::new(pubkey(42))
1436                         .description("foo".into())
1437                         .build()
1438                         .unwrap();
1439                 assert_eq!(offer.description(), Some(PrintableString("foo")));
1440                 assert_eq!(offer.as_tlv_stream().description, Some(&String::from("foo")));
1441
1442                 let offer = OfferBuilder::new(pubkey(42))
1443                         .description("foo".into())
1444                         .description("bar".into())
1445                         .build()
1446                         .unwrap();
1447                 assert_eq!(offer.description(), Some(PrintableString("bar")));
1448                 assert_eq!(offer.as_tlv_stream().description, Some(&String::from("bar")));
1449
1450                 let offer = OfferBuilder::new(pubkey(42))
1451                         .amount_msats(1000)
1452                         .build()
1453                         .unwrap();
1454                 assert_eq!(offer.description(), Some(PrintableString("")));
1455                 assert_eq!(offer.as_tlv_stream().description, Some(&String::from("")));
1456         }
1457
1458         #[test]
1459         fn builds_offer_with_features() {
1460                 let offer = OfferBuilder::new(pubkey(42))
1461                         .features_unchecked(OfferFeatures::unknown())
1462                         .build()
1463                         .unwrap();
1464                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1465                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1466
1467                 let offer = OfferBuilder::new(pubkey(42))
1468                         .features_unchecked(OfferFeatures::unknown())
1469                         .features_unchecked(OfferFeatures::empty())
1470                         .build()
1471                         .unwrap();
1472                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1473                 assert_eq!(offer.as_tlv_stream().features, None);
1474         }
1475
1476         #[test]
1477         fn builds_offer_with_absolute_expiry() {
1478                 let future_expiry = Duration::from_secs(u64::max_value());
1479                 let past_expiry = Duration::from_secs(0);
1480                 let now = future_expiry - Duration::from_secs(1_000);
1481
1482                 let offer = OfferBuilder::new(pubkey(42))
1483                         .absolute_expiry(future_expiry)
1484                         .build()
1485                         .unwrap();
1486                 #[cfg(feature = "std")]
1487                 assert!(!offer.is_expired());
1488                 assert!(!offer.is_expired_no_std(now));
1489                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1490                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1491
1492                 let offer = OfferBuilder::new(pubkey(42))
1493                         .absolute_expiry(future_expiry)
1494                         .absolute_expiry(past_expiry)
1495                         .build()
1496                         .unwrap();
1497                 #[cfg(feature = "std")]
1498                 assert!(offer.is_expired());
1499                 assert!(offer.is_expired_no_std(now));
1500                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1501                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1502         }
1503
1504         #[test]
1505         fn builds_offer_with_paths() {
1506                 let paths = vec![
1507                         BlindedPath {
1508                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1509                                 blinding_point: pubkey(41),
1510                                 blinded_hops: vec![
1511                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1512                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1513                                 ],
1514                         },
1515                         BlindedPath {
1516                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1517                                 blinding_point: pubkey(41),
1518                                 blinded_hops: vec![
1519                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1520                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1521                                 ],
1522                         },
1523                 ];
1524
1525                 let offer = OfferBuilder::new(pubkey(42))
1526                         .path(paths[0].clone())
1527                         .path(paths[1].clone())
1528                         .build()
1529                         .unwrap();
1530                 let tlv_stream = offer.as_tlv_stream();
1531                 assert_eq!(offer.paths(), paths.as_slice());
1532                 assert_eq!(offer.signing_pubkey(), Some(pubkey(42)));
1533                 assert_ne!(pubkey(42), pubkey(44));
1534                 assert_eq!(tlv_stream.paths, Some(&paths));
1535                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1536         }
1537
1538         #[test]
1539         fn builds_offer_with_issuer() {
1540                 let offer = OfferBuilder::new(pubkey(42))
1541                         .issuer("foo".into())
1542                         .build()
1543                         .unwrap();
1544                 assert_eq!(offer.issuer(), Some(PrintableString("foo")));
1545                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("foo")));
1546
1547                 let offer = OfferBuilder::new(pubkey(42))
1548                         .issuer("foo".into())
1549                         .issuer("bar".into())
1550                         .build()
1551                         .unwrap();
1552                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1553                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1554         }
1555
1556         #[test]
1557         fn builds_offer_with_supported_quantity() {
1558                 let one = NonZeroU64::new(1).unwrap();
1559                 let ten = NonZeroU64::new(10).unwrap();
1560
1561                 let offer = OfferBuilder::new(pubkey(42))
1562                         .supported_quantity(Quantity::One)
1563                         .build()
1564                         .unwrap();
1565                 let tlv_stream = offer.as_tlv_stream();
1566                 assert!(!offer.expects_quantity());
1567                 assert_eq!(offer.supported_quantity(), Quantity::One);
1568                 assert_eq!(tlv_stream.quantity_max, None);
1569
1570                 let offer = OfferBuilder::new(pubkey(42))
1571                         .supported_quantity(Quantity::Unbounded)
1572                         .build()
1573                         .unwrap();
1574                 let tlv_stream = offer.as_tlv_stream();
1575                 assert!(offer.expects_quantity());
1576                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1577                 assert_eq!(tlv_stream.quantity_max, Some(0));
1578
1579                 let offer = OfferBuilder::new(pubkey(42))
1580                         .supported_quantity(Quantity::Bounded(ten))
1581                         .build()
1582                         .unwrap();
1583                 let tlv_stream = offer.as_tlv_stream();
1584                 assert!(offer.expects_quantity());
1585                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1586                 assert_eq!(tlv_stream.quantity_max, Some(10));
1587
1588                 let offer = OfferBuilder::new(pubkey(42))
1589                         .supported_quantity(Quantity::Bounded(one))
1590                         .build()
1591                         .unwrap();
1592                 let tlv_stream = offer.as_tlv_stream();
1593                 assert!(offer.expects_quantity());
1594                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1595                 assert_eq!(tlv_stream.quantity_max, Some(1));
1596
1597                 let offer = OfferBuilder::new(pubkey(42))
1598                         .supported_quantity(Quantity::Bounded(ten))
1599                         .supported_quantity(Quantity::One)
1600                         .build()
1601                         .unwrap();
1602                 let tlv_stream = offer.as_tlv_stream();
1603                 assert!(!offer.expects_quantity());
1604                 assert_eq!(offer.supported_quantity(), Quantity::One);
1605                 assert_eq!(tlv_stream.quantity_max, None);
1606         }
1607
1608         #[test]
1609         fn fails_requesting_invoice_with_unknown_required_features() {
1610                 match OfferBuilder::new(pubkey(42))
1611                         .features_unchecked(OfferFeatures::unknown())
1612                         .build().unwrap()
1613                         .request_invoice(vec![1; 32], pubkey(43))
1614                 {
1615                         Ok(_) => panic!("expected error"),
1616                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1617                 }
1618         }
1619
1620         #[test]
1621         fn parses_offer_with_chains() {
1622                 let offer = OfferBuilder::new(pubkey(42))
1623                         .chain(Network::Bitcoin)
1624                         .chain(Network::Testnet)
1625                         .build()
1626                         .unwrap();
1627                 if let Err(e) = offer.to_string().parse::<Offer>() {
1628                         panic!("error parsing offer: {:?}", e);
1629                 }
1630         }
1631
1632         #[test]
1633         fn parses_offer_with_amount() {
1634                 let offer = OfferBuilder::new(pubkey(42))
1635                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1636                         .build()
1637                         .unwrap();
1638                 if let Err(e) = offer.to_string().parse::<Offer>() {
1639                         panic!("error parsing offer: {:?}", e);
1640                 }
1641
1642                 let mut tlv_stream = offer.as_tlv_stream();
1643                 tlv_stream.amount = Some(1000);
1644                 tlv_stream.currency = Some(b"USD");
1645
1646                 let mut encoded_offer = Vec::new();
1647                 tlv_stream.write(&mut encoded_offer).unwrap();
1648
1649                 if let Err(e) = Offer::try_from(encoded_offer) {
1650                         panic!("error parsing offer: {:?}", e);
1651                 }
1652
1653                 let mut tlv_stream = offer.as_tlv_stream();
1654                 tlv_stream.amount = None;
1655                 tlv_stream.currency = Some(b"USD");
1656
1657                 let mut encoded_offer = Vec::new();
1658                 tlv_stream.write(&mut encoded_offer).unwrap();
1659
1660                 match Offer::try_from(encoded_offer) {
1661                         Ok(_) => panic!("expected error"),
1662                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1663                 }
1664
1665                 let mut tlv_stream = offer.as_tlv_stream();
1666                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1667                 tlv_stream.currency = None;
1668
1669                 let mut encoded_offer = Vec::new();
1670                 tlv_stream.write(&mut encoded_offer).unwrap();
1671
1672                 match Offer::try_from(encoded_offer) {
1673                         Ok(_) => panic!("expected error"),
1674                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1675                 }
1676         }
1677
1678         #[test]
1679         fn parses_offer_with_description() {
1680                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1681                 if let Err(e) = offer.to_string().parse::<Offer>() {
1682                         panic!("error parsing offer: {:?}", e);
1683                 }
1684
1685                 let offer = OfferBuilder::new(pubkey(42))
1686                         .description("foo".to_string())
1687                         .amount_msats(1000)
1688                         .build().unwrap();
1689                 if let Err(e) = offer.to_string().parse::<Offer>() {
1690                         panic!("error parsing offer: {:?}", e);
1691                 }
1692
1693                 let mut tlv_stream = offer.as_tlv_stream();
1694                 tlv_stream.description = None;
1695
1696                 let mut encoded_offer = Vec::new();
1697                 tlv_stream.write(&mut encoded_offer).unwrap();
1698
1699                 match Offer::try_from(encoded_offer) {
1700                         Ok(_) => panic!("expected error"),
1701                         Err(e) => {
1702                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1703                         },
1704                 }
1705         }
1706
1707         #[test]
1708         fn parses_offer_with_paths() {
1709                 let offer = OfferBuilder::new(pubkey(42))
1710                         .path(BlindedPath {
1711                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1712                                 blinding_point: pubkey(41),
1713                                 blinded_hops: vec![
1714                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1715                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1716                                 ],
1717                         })
1718                         .path(BlindedPath {
1719                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1720                                 blinding_point: pubkey(41),
1721                                 blinded_hops: vec![
1722                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1723                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1724                                 ],
1725                         })
1726                         .build()
1727                         .unwrap();
1728                 if let Err(e) = offer.to_string().parse::<Offer>() {
1729                         panic!("error parsing offer: {:?}", e);
1730                 }
1731
1732                 let offer = OfferBuilder::new(pubkey(42))
1733                         .path(BlindedPath {
1734                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1735                                 blinding_point: pubkey(41),
1736                                 blinded_hops: vec![
1737                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1738                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1739                                 ],
1740                         })
1741                         .clear_signing_pubkey()
1742                         .build()
1743                         .unwrap();
1744                 if let Err(e) = offer.to_string().parse::<Offer>() {
1745                         panic!("error parsing offer: {:?}", e);
1746                 }
1747
1748                 let mut builder = OfferBuilder::new(pubkey(42));
1749                 builder.offer.paths = Some(vec![]);
1750
1751                 let offer = builder.build().unwrap();
1752                 match offer.to_string().parse::<Offer>() {
1753                         Ok(_) => panic!("expected error"),
1754                         Err(e) => {
1755                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPaths));
1756                         },
1757                 }
1758         }
1759
1760         #[test]
1761         fn parses_offer_with_quantity() {
1762                 let offer = OfferBuilder::new(pubkey(42))
1763                         .supported_quantity(Quantity::One)
1764                         .build()
1765                         .unwrap();
1766                 if let Err(e) = offer.to_string().parse::<Offer>() {
1767                         panic!("error parsing offer: {:?}", e);
1768                 }
1769
1770                 let offer = OfferBuilder::new(pubkey(42))
1771                         .supported_quantity(Quantity::Unbounded)
1772                         .build()
1773                         .unwrap();
1774                 if let Err(e) = offer.to_string().parse::<Offer>() {
1775                         panic!("error parsing offer: {:?}", e);
1776                 }
1777
1778                 let offer = OfferBuilder::new(pubkey(42))
1779                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1780                         .build()
1781                         .unwrap();
1782                 if let Err(e) = offer.to_string().parse::<Offer>() {
1783                         panic!("error parsing offer: {:?}", e);
1784                 }
1785
1786                 let offer = OfferBuilder::new(pubkey(42))
1787                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1788                         .build()
1789                         .unwrap();
1790                 if let Err(e) = offer.to_string().parse::<Offer>() {
1791                         panic!("error parsing offer: {:?}", e);
1792                 }
1793         }
1794
1795         #[test]
1796         fn parses_offer_with_node_id() {
1797                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1798                 if let Err(e) = offer.to_string().parse::<Offer>() {
1799                         panic!("error parsing offer: {:?}", e);
1800                 }
1801
1802                 let mut tlv_stream = offer.as_tlv_stream();
1803                 tlv_stream.node_id = None;
1804
1805                 let mut encoded_offer = Vec::new();
1806                 tlv_stream.write(&mut encoded_offer).unwrap();
1807
1808                 match Offer::try_from(encoded_offer) {
1809                         Ok(_) => panic!("expected error"),
1810                         Err(e) => {
1811                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1812                         },
1813                 }
1814         }
1815
1816         #[test]
1817         fn fails_parsing_offer_with_extra_tlv_records() {
1818                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1819
1820                 let mut encoded_offer = Vec::new();
1821                 offer.write(&mut encoded_offer).unwrap();
1822                 BigSize(80).write(&mut encoded_offer).unwrap();
1823                 BigSize(32).write(&mut encoded_offer).unwrap();
1824                 [42u8; 32].write(&mut encoded_offer).unwrap();
1825
1826                 match Offer::try_from(encoded_offer) {
1827                         Ok(_) => panic!("expected error"),
1828                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1829                 }
1830         }
1831 }
1832
1833 #[cfg(test)]
1834 mod bolt12_tests {
1835         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1836         use crate::ln::msgs::DecodeError;
1837
1838         #[test]
1839         fn parses_bech32_encoded_offers() {
1840                 let offers = [
1841                         // Minimal bolt12 offer
1842                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1843
1844                         // for testnet
1845                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1846
1847                         // for bitcoin (redundant)
1848                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1849
1850                         // for bitcoin or liquidv1
1851                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1852
1853                         // with metadata
1854                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1855
1856                         // with amount
1857                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1858
1859                         // with currency
1860                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1861
1862                         // with expiry
1863                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1864
1865                         // with issuer
1866                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1867
1868                         // with quantity
1869                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1870
1871                         // with unlimited (or unknown) quantity
1872                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1873
1874                         // with single quantity (weird but valid)
1875                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1876
1877                         // with feature
1878                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1879
1880                         // with blinded path via Bob (0x424242...), blinding 020202...
1881                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1882
1883                         // ... and with sciddir introduction node
1884                         "lno1pgx9getnwss8vetrw3hhyucs3yqqqqqqqqqqqqp2qgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqyqqqqqqqqqqqqqqqqqqqqqqqqqqqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqqgzyg3zyg3zyg3z93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1885
1886                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1887                         "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",
1888
1889                         // unknown odd field
1890                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1891                 ];
1892                 for encoded_offer in &offers {
1893                         if let Err(e) = encoded_offer.parse::<Offer>() {
1894                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1895                         }
1896                 }
1897         }
1898
1899         #[test]
1900         fn fails_parsing_bech32_encoded_offers() {
1901                 // Malformed: fields out of order
1902                 assert_eq!(
1903                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1904                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1905                 );
1906
1907                 // Malformed: unknown even TLV type 78
1908                 assert_eq!(
1909                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1910                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1911                 );
1912
1913                 // Malformed: empty
1914                 assert_eq!(
1915                         "lno1".parse::<Offer>(),
1916                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1917                 );
1918
1919                 // Malformed: truncated at type
1920                 assert_eq!(
1921                         "lno1pg".parse::<Offer>(),
1922                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1923                 );
1924
1925                 // Malformed: truncated in length
1926                 assert_eq!(
1927                         "lno1pt7s".parse::<Offer>(),
1928                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1929                 );
1930
1931                 // Malformed: truncated after length
1932                 assert_eq!(
1933                         "lno1pgpq".parse::<Offer>(),
1934                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1935                 );
1936
1937                 // Malformed: truncated in description
1938                 assert_eq!(
1939                         "lno1pgpyz".parse::<Offer>(),
1940                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1941                 );
1942
1943                 // Malformed: invalid offer_chains length
1944                 assert_eq!(
1945                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1946                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1947                 );
1948
1949                 // Malformed: truncated currency UTF-8
1950                 assert_eq!(
1951                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1952                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1953                 );
1954
1955                 // Malformed: invalid currency UTF-8
1956                 assert_eq!(
1957                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1958                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1959                 );
1960
1961                 // Malformed: truncated description UTF-8
1962                 assert_eq!(
1963                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1964                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1965                 );
1966
1967                 // Malformed: invalid description UTF-8
1968                 assert_eq!(
1969                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1970                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1971                 );
1972
1973                 // Malformed: truncated offer_paths
1974                 assert_eq!(
1975                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1976                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1977                 );
1978
1979                 // Malformed: zero num_hops in blinded_path
1980                 assert_eq!(
1981                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1982                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1983                 );
1984
1985                 // Malformed: truncated onionmsg_hop in blinded_path
1986                 assert_eq!(
1987                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1988                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1989                 );
1990
1991                 // Malformed: bad first_node_id in blinded_path
1992                 assert_eq!(
1993                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1994                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1995                 );
1996
1997                 // Malformed: bad blinding in blinded_path
1998                 assert_eq!(
1999                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
2000                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
2001                 );
2002
2003                 // Malformed: bad blinded_node_id in onionmsg_hop
2004                 assert_eq!(
2005                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
2006                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
2007                 );
2008
2009                 // Malformed: truncated issuer UTF-8
2010                 assert_eq!(
2011                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
2012                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2013                 );
2014
2015                 // Malformed: invalid issuer UTF-8
2016                 assert_eq!(
2017                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
2018                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2019                 );
2020
2021                 // Malformed: invalid offer_node_id
2022                 assert_eq!(
2023                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
2024                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2025                 );
2026
2027                 // Contains type >= 80
2028                 assert_eq!(
2029                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
2030                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2031                 );
2032
2033                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
2034                 // Contains unknown feature 22
2035                 assert!(
2036                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
2037                 );
2038
2039                 // Missing offer_description
2040                 assert_eq!(
2041                         // TODO: Match the spec once it is updated.
2042                         "lno1pqpq86qkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>(),
2043                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
2044                 );
2045
2046                 // Missing offer_node_id"
2047                 assert_eq!(
2048                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
2049                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
2050                 );
2051         }
2052 }