_ 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                 $contents.signing_pubkey()
 625         }
 626 } }
 627
 628 impl Offer {
 629         offer_accessors!(self, self.contents);
 630
 631         /// Returns the id of the offer.
 632         pub fn id(&self) -> OfferId {
 633                 self.id
 634         }
 635
 636         pub(super) fn implied_chain(&self) -> ChainHash {
 637                 self.contents.implied_chain()
 638         }
 639
 640         /// Returns whether the given chain is supported by the offer.
 641         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 642                 self.contents.supports_chain(chain)
 643         }
 644
 645         /// Whether the offer has expired.
 646         #[cfg(feature = "std")]
 647         pub fn is_expired(&self) -> bool {
 648                 self.contents.is_expired()
 649         }
 650
 651         /// Whether the offer has expired given the duration since the Unix epoch.
 652         pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 653                 self.contents.is_expired_no_std(duration_since_epoch)
 654         }
 655
 656         /// Returns whether the given quantity is valid for the offer.
 657         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 658                 self.contents.is_valid_quantity(quantity)
 659         }
 660
 661         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 662         ///
 663         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 664         pub fn expects_quantity(&self) -> bool {
 665                 self.contents.expects_quantity()
 666         }
 667 }
 668
 669 macro_rules! request_invoice_derived_payer_id { ($self: ident, $builder: ty) => {
 670         /// Similar to [`Offer::request_invoice`] except it:
 671         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 672         ///   request,
 673         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 674         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 675         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 676         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 677         ///   be used when sending the payment for the requested invoice.
 678         ///
 679         /// Useful to protect the sender's privacy.
 680         ///
 681         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 682         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 683         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 684         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 685         pub fn request_invoice_deriving_payer_id<
 686                 'a, 'b, ES: Deref,
 687                 #[cfg(not(c_bindings))]
 688                 T: secp256k1::Signing
 689         >(
 690                 &'a $self, expanded_key: &ExpandedKey, entropy_source: ES,
 691                 #[cfg(not(c_bindings))]
 692                 secp_ctx: &'b Secp256k1<T>,
 693                 #[cfg(c_bindings)]
 694                 secp_ctx: &'b Secp256k1<secp256k1::All>,
 695                 payment_id: PaymentId
 696         ) -> Result<$builder, Bolt12SemanticError>
 697         where
 698                 ES::Target: EntropySource,
 699         {
 700                 if $self.offer_features().requires_unknown_bits() {
 701                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 702                 }
 703
 704                 Ok(<$builder>::deriving_payer_id($self, expanded_key, entropy_source, secp_ctx, payment_id))
 705         }
 706 } }
 707
 708 macro_rules! request_invoice_explicit_payer_id { ($self: ident, $builder: ty) => {
 709         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 710         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 711         ///
 712         /// Useful for recurring payments using the same `payer_id` with different invoices.
 713         ///
 714         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 715         pub fn request_invoice_deriving_metadata<ES: Deref>(
 716                 &$self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 717                 payment_id: PaymentId
 718         ) -> Result<$builder, Bolt12SemanticError>
 719         where
 720                 ES::Target: EntropySource,
 721         {
 722                 if $self.offer_features().requires_unknown_bits() {
 723                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 724                 }
 725
 726                 Ok(<$builder>::deriving_metadata($self, payer_id, expanded_key, entropy_source, payment_id))
 727         }
 728
 729         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 730         /// which will be reflected in the `Bolt12Invoice` response.
 731         ///
 732         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 733         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 734         /// hashing in the signature calculation.
 735         ///
 736         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 737         /// Otherwise, payments may be correlated.
 738         ///
 739         /// Errors if the offer contains unknown required features.
 740         ///
 741         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 742         pub fn request_invoice(
 743                 &$self, metadata: Vec<u8>, payer_id: PublicKey
 744         ) -> Result<$builder, Bolt12SemanticError> {
 745                 if $self.offer_features().requires_unknown_bits() {
 746                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 747                 }
 748
 749                 Ok(<$builder>::new($self, metadata, payer_id))
 750         }
 751 } }
 752
 753 #[cfg(not(c_bindings))]
 754 impl Offer {
 755         request_invoice_derived_payer_id!(self, InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>);
 756         request_invoice_explicit_payer_id!(self, InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>);
 757 }
 758
 759 #[cfg(c_bindings)]
 760 impl Offer {
 761         request_invoice_derived_payer_id!(self, InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>);
 762         request_invoice_explicit_payer_id!(self, InvoiceRequestWithExplicitPayerIdBuilder);
 763 }
 764
 765 #[cfg(test)]
 766 impl Offer {
 767         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 768                 self.contents.as_tlv_stream()
 769         }
 770 }
 771
 772 impl AsRef<[u8]> for Offer {
 773         fn as_ref(&self) -> &[u8] {
 774                 &self.bytes
 775         }
 776 }
 777
 778 impl PartialEq for Offer {
 779         fn eq(&self, other: &Self) -> bool {
 780                 self.bytes.eq(&other.bytes)
 781         }
 782 }
 783
 784 impl Eq for Offer {}
 785
 786 impl Hash for Offer {
 787         fn hash<H: Hasher>(&self, state: &mut H) {
 788                 self.bytes.hash(state);
 789         }
 790 }
 791
 792 impl OfferContents {
 793         pub fn chains(&self) -> Vec<ChainHash> {
 794                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 795         }
 796
 797         pub fn implied_chain(&self) -> ChainHash {
 798                 ChainHash::using_genesis_block(Network::Bitcoin)
 799         }
 800
 801         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 802                 self.chains().contains(&chain)
 803         }
 804
 805         pub fn metadata(&self) -> Option<&Vec<u8>> {
 806                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 807         }
 808
 809         pub fn amount(&self) -> Option<Amount> {
 810                 self.amount
 811         }
 812
 813         pub fn description(&self) -> Option<PrintableString> {
 814                 self.description.as_ref().map(|description| PrintableString(description))
 815         }
 816
 817         pub fn features(&self) -> &OfferFeatures {
 818                 &self.features
 819         }
 820
 821         pub fn absolute_expiry(&self) -> Option<Duration> {
 822                 self.absolute_expiry
 823         }
 824
 825         #[cfg(feature = "std")]
 826         pub(super) fn is_expired(&self) -> bool {
 827                 SystemTime::UNIX_EPOCH
 828                         .elapsed()
 829                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 830                         .unwrap_or(false)
 831         }
 832
 833         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 834                 self.absolute_expiry
 835                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 836                         .unwrap_or(false)
 837         }
 838
 839         pub fn issuer(&self) -> Option<PrintableString> {
 840                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 841         }
 842
 843         pub fn paths(&self) -> &[BlindedPath] {
 844                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 845         }
 846
 847         pub(super) fn check_amount_msats_for_quantity(
 848                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 849         ) -> Result<(), Bolt12SemanticError> {
 850                 let offer_amount_msats = match self.amount {
 851                         None => 0,
 852                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 853                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 854                 };
 855
 856                 if !self.expects_quantity() || quantity.is_some() {
 857                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 858                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 859                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 860
 861                         if amount_msats < expected_amount_msats {
 862                                 return Err(Bolt12SemanticError::InsufficientAmount);
 863                         }
 864
 865                         if amount_msats > MAX_VALUE_MSAT {
 866                                 return Err(Bolt12SemanticError::InvalidAmount);
 867                         }
 868                 }
 869
 870                 Ok(())
 871         }
 872
 873         pub fn supported_quantity(&self) -> Quantity {
 874                 self.supported_quantity
 875         }
 876
 877         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 878                 let expects_quantity = self.expects_quantity();
 879                 match quantity {
 880                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 881                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 882                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 883                                 Err(Bolt12SemanticError::InvalidQuantity)
 884                         },
 885                         _ => Ok(()),
 886                 }
 887         }
 888
 889         fn is_valid_quantity(&self, quantity: u64) -> bool {
 890                 match self.supported_quantity {
 891                         Quantity::Bounded(n) => quantity <= n.get(),
 892                         Quantity::Unbounded => quantity > 0,
 893                         Quantity::One => quantity == 1,
 894                 }
 895         }
 896
 897         fn expects_quantity(&self) -> bool {
 898                 match self.supported_quantity {
 899                         Quantity::Bounded(_) => true,
 900                         Quantity::Unbounded => true,
 901                         Quantity::One => false,
 902                 }
 903         }
 904
 905         pub(super) fn signing_pubkey(&self) -> Option<PublicKey> {
 906                 self.signing_pubkey
 907         }
 908
 909         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 910         pub(super) fn verify<T: secp256k1::Signing>(
 911                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 912         ) -> Result<(OfferId, Option<Keypair>), ()> {
 913                 match self.metadata() {
 914                         Some(metadata) => {
 915                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 916                                         match record.r#type {
 917                                                 OFFER_METADATA_TYPE => false,
 918                                                 OFFER_NODE_ID_TYPE => {
 919                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 920                                                 },
 921                                                 _ => true,
 922                                         }
 923                                 });
 924                                 let signing_pubkey = match self.signing_pubkey() {
 925                                         Some(signing_pubkey) => signing_pubkey,
 926                                         None => return Err(()),
 927                                 };
 928                                 let keys = signer::verify_recipient_metadata(
 929                                         metadata, key, IV_BYTES, signing_pubkey, tlv_stream, secp_ctx
 930                                 )?;
 931
 932                                 let offer_id = OfferId::from_valid_invreq_tlv_stream(bytes);
 933
 934                                 Ok((offer_id, keys))
 935                         },
 936                         None => Err(()),
 937                 }
 938         }
 939
 940         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 941                 let (currency, amount) = match &self.amount {
 942                         None => (None, None),
 943                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 944                         Some(Amount::Currency { iso4217_code, amount }) => (
 945                                 Some(iso4217_code), Some(*amount)
 946                         ),
 947                 };
 948
 949                 let features = {
 950                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 951                 };
 952
 953                 OfferTlvStreamRef {
 954                         chains: self.chains.as_ref(),
 955                         metadata: self.metadata(),
 956                         currency,
 957                         amount,
 958                         description: self.description.as_ref(),
 959                         features,
 960                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 961                         paths: self.paths.as_ref(),
 962                         issuer: self.issuer.as_ref(),
 963                         quantity_max: self.supported_quantity.to_tlv_record(),
 964                         node_id: self.signing_pubkey.as_ref(),
 965                 }
 966         }
 967 }
 968
 969 impl Readable for Offer {
 970         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 971                 let bytes: WithoutLength<Vec<u8>> = Readable::read(reader)?;
 972                 Self::try_from(bytes.0).map_err(|_| DecodeError::InvalidValue)
 973         }
 974 }
 975
 976 impl Writeable for Offer {
 977         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 978                 WithoutLength(&self.bytes).write(writer)
 979         }
 980 }
 981
 982 impl Writeable for OfferContents {
 983         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 984                 self.as_tlv_stream().write(writer)
 985         }
 986 }
 987
 988 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 989 /// another currency.
 990 #[derive(Clone, Copy, Debug, PartialEq)]
 991 pub enum Amount {
 992         /// An amount of bitcoin.
 993         Bitcoin {
 994                 /// The amount in millisatoshi.
 995                 amount_msats: u64,
 996         },
 997         /// An amount of currency specified using ISO 4712.
 998         Currency {
 999                 /// The currency that the amount is denominated in.
1000                 iso4217_code: CurrencyCode,
1001                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
1002                 amount: u64,
1003         },
1004 }
1005
1006 /// An ISO 4712 three-letter currency code (e.g., USD).
1007 pub type CurrencyCode = [u8; 3];
1008
1009 /// Quantity of items supported by an [`Offer`].
1010 #[derive(Clone, Copy, Debug, PartialEq)]
1011 pub enum Quantity {
1012         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
1013         /// but is limited (e.g., because of per customer or inventory limits).
1014         ///
1015         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
1016         /// is supported.
1017         Bounded(NonZeroU64),
1018         /// One or more items. Use when more than one item can be requested without any limit.
1019         Unbounded,
1020         /// Only one item. Use when only a single item can be requested.
1021         One,
1022 }
1023
1024 impl Quantity {
1025         fn to_tlv_record(&self) -> Option<u64> {
1026                 match self {
1027                         Quantity::Bounded(n) => Some(n.get()),
1028                         Quantity::Unbounded => Some(0),
1029                         Quantity::One => None,
1030                 }
1031         }
1032 }
1033
1034 /// Valid type range for offer TLV records.
1035 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
1036
1037 /// TLV record type for [`Offer::metadata`].
1038 const OFFER_METADATA_TYPE: u64 = 4;
1039
1040 /// TLV record type for [`Offer::signing_pubkey`].
1041 const OFFER_NODE_ID_TYPE: u64 = 22;
1042
1043 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
1044         (2, chains: (Vec<ChainHash>, WithoutLength)),
1045         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
1046         (6, currency: CurrencyCode),
1047         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
1048         (10, description: (String, WithoutLength)),
1049         (12, features: (OfferFeatures, WithoutLength)),
1050         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
1051         (16, paths: (Vec<BlindedPath>, WithoutLength)),
1052         (18, issuer: (String, WithoutLength)),
1053         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
1054         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
1055 });
1056
1057 impl Bech32Encode for Offer {
1058         const BECH32_HRP: &'static str = "lno";
1059 }
1060
1061 impl FromStr for Offer {
1062         type Err = Bolt12ParseError;
1063
1064         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
1065                 Self::from_bech32_str(s)
1066         }
1067 }
1068
1069 impl TryFrom<Vec<u8>> for Offer {
1070         type Error = Bolt12ParseError;
1071
1072         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1073                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
1074                 let ParsedMessage { bytes, tlv_stream } = offer;
1075                 let contents = OfferContents::try_from(tlv_stream)?;
1076                 let id = OfferId::from_valid_offer_tlv_stream(&bytes);
1077
1078                 Ok(Offer { bytes, contents, id })
1079         }
1080 }
1081
1082 impl TryFrom<OfferTlvStream> for OfferContents {
1083         type Error = Bolt12SemanticError;
1084
1085         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
1086                 let OfferTlvStream {
1087                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
1088                         issuer, quantity_max, node_id,
1089                 } = tlv_stream;
1090
1091                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
1092
1093                 let amount = match (currency, amount) {
1094                         (None, None) => None,
1095                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
1096                                 return Err(Bolt12SemanticError::InvalidAmount);
1097                         },
1098                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
1099                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
1100                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
1101                 };
1102
1103                 if amount.is_some() && description.is_none() {
1104                         return Err(Bolt12SemanticError::MissingDescription);
1105                 }
1106
1107                 let features = features.unwrap_or_else(OfferFeatures::empty);
1108
1109                 let absolute_expiry = absolute_expiry
1110                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
1111
1112                 let supported_quantity = match quantity_max {
1113                         None => Quantity::One,
1114                         Some(0) => Quantity::Unbounded,
1115                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
1116                 };
1117
1118                 let (signing_pubkey, paths) = match (node_id, paths) {
1119                         (None, None) => return Err(Bolt12SemanticError::MissingSigningPubkey),
1120                         (_, Some(paths)) if paths.is_empty() => return Err(Bolt12SemanticError::MissingPaths),
1121                         (node_id, paths) => (node_id, paths),
1122                 };
1123
1124                 Ok(OfferContents {
1125                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
1126                         supported_quantity, signing_pubkey,
1127                 })
1128         }
1129 }
1130
1131 impl core::fmt::Display for Offer {
1132         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1133                 self.fmt_bech32_str(f)
1134         }
1135 }
1136
1137 #[cfg(test)]
1138 mod tests {
1139         use super::{Amount, Offer, OfferTlvStreamRef, Quantity};
1140         #[cfg(not(c_bindings))]
1141         use {
1142                 super::OfferBuilder,
1143         };
1144         #[cfg(c_bindings)]
1145         use {
1146                 super::OfferWithExplicitMetadataBuilder as OfferBuilder,
1147         };
1148
1149         use bitcoin::blockdata::constants::ChainHash;
1150         use bitcoin::network::Network;
1151         use bitcoin::secp256k1::Secp256k1;
1152         use core::num::NonZeroU64;
1153         use core::time::Duration;
1154         use crate::blinded_path::{BlindedHop, BlindedPath, IntroductionNode};
1155         use crate::sign::KeyMaterial;
1156         use crate::ln::features::OfferFeatures;
1157         use crate::ln::inbound_payment::ExpandedKey;
1158         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1159         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1160         use crate::offers::test_utils::*;
1161         use crate::util::ser::{BigSize, Writeable};
1162         use crate::util::string::PrintableString;
1163
1164         #[test]
1165         fn builds_offer_with_defaults() {
1166                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1167
1168                 let mut buffer = Vec::new();
1169                 offer.write(&mut buffer).unwrap();
1170
1171                 assert_eq!(offer.bytes, buffer.as_slice());
1172                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1173                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
1174                 assert_eq!(offer.metadata(), None);
1175                 assert_eq!(offer.amount(), None);
1176                 assert_eq!(offer.description(), None);
1177                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1178                 assert_eq!(offer.absolute_expiry(), None);
1179                 #[cfg(feature = "std")]
1180                 assert!(!offer.is_expired());
1181                 assert_eq!(offer.paths(), &[]);
1182                 assert_eq!(offer.issuer(), None);
1183                 assert_eq!(offer.supported_quantity(), Quantity::One);
1184                 assert!(!offer.expects_quantity());
1185                 assert_eq!(offer.signing_pubkey(), Some(pubkey(42)));
1186
1187                 assert_eq!(
1188                         offer.as_tlv_stream(),
1189                         OfferTlvStreamRef {
1190                                 chains: None,
1191                                 metadata: None,
1192                                 currency: None,
1193                                 amount: None,
1194                                 description: None,
1195                                 features: None,
1196                                 absolute_expiry: None,
1197                                 paths: None,
1198                                 issuer: None,
1199                                 quantity_max: None,
1200                                 node_id: Some(&pubkey(42)),
1201                         },
1202                 );
1203
1204                 if let Err(e) = Offer::try_from(buffer) {
1205                         panic!("error parsing offer: {:?}", e);
1206                 }
1207         }
1208
1209         #[test]
1210         fn builds_offer_with_chains() {
1211                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1212                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1213
1214                 let offer = OfferBuilder::new(pubkey(42))
1215                         .chain(Network::Bitcoin)
1216                         .build()
1217                         .unwrap();
1218                 assert!(offer.supports_chain(mainnet));
1219                 assert_eq!(offer.chains(), vec![mainnet]);
1220                 assert_eq!(offer.as_tlv_stream().chains, None);
1221
1222                 let offer = OfferBuilder::new(pubkey(42))
1223                         .chain(Network::Testnet)
1224                         .build()
1225                         .unwrap();
1226                 assert!(offer.supports_chain(testnet));
1227                 assert_eq!(offer.chains(), vec![testnet]);
1228                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1229
1230                 let offer = OfferBuilder::new(pubkey(42))
1231                         .chain(Network::Testnet)
1232                         .chain(Network::Testnet)
1233                         .build()
1234                         .unwrap();
1235                 assert!(offer.supports_chain(testnet));
1236                 assert_eq!(offer.chains(), vec![testnet]);
1237                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1238
1239                 let offer = OfferBuilder::new(pubkey(42))
1240                         .chain(Network::Bitcoin)
1241                         .chain(Network::Testnet)
1242                         .build()
1243                         .unwrap();
1244                 assert!(offer.supports_chain(mainnet));
1245                 assert!(offer.supports_chain(testnet));
1246                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1247                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1248         }
1249
1250         #[test]
1251         fn builds_offer_with_metadata() {
1252                 let offer = OfferBuilder::new(pubkey(42))
1253                         .metadata(vec![42; 32]).unwrap()
1254                         .build()
1255                         .unwrap();
1256                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1257                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1258
1259                 let offer = OfferBuilder::new(pubkey(42))
1260                         .metadata(vec![42; 32]).unwrap()
1261                         .metadata(vec![43; 32]).unwrap()
1262                         .build()
1263                         .unwrap();
1264                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1265                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1266         }
1267
1268         #[test]
1269         fn builds_offer_with_metadata_derived() {
1270                 let node_id = recipient_pubkey();
1271                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1272                 let entropy = FixedEntropy {};
1273                 let secp_ctx = Secp256k1::new();
1274
1275                 #[cfg(c_bindings)]
1276                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1277                 let offer = OfferBuilder
1278                         ::deriving_signing_pubkey(node_id, &expanded_key, &entropy, &secp_ctx)
1279                         .amount_msats(1000)
1280                         .build().unwrap();
1281                 assert_eq!(offer.signing_pubkey(), Some(node_id));
1282
1283                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1284                         .build().unwrap()
1285                         .sign(payer_sign).unwrap();
1286                 match invoice_request.verify(&expanded_key, &secp_ctx) {
1287                         Ok(invoice_request) => assert_eq!(invoice_request.offer_id, offer.id()),
1288                         Err(_) => panic!("unexpected error"),
1289                 }
1290
1291                 // Fails verification with altered offer field
1292                 let mut tlv_stream = offer.as_tlv_stream();
1293                 tlv_stream.amount = Some(100);
1294
1295                 let mut encoded_offer = Vec::new();
1296                 tlv_stream.write(&mut encoded_offer).unwrap();
1297
1298                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1299                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1300                         .build().unwrap()
1301                         .sign(payer_sign).unwrap();
1302                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1303
1304                 // Fails verification with altered metadata
1305                 let mut tlv_stream = offer.as_tlv_stream();
1306                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1307                 tlv_stream.metadata = Some(&metadata);
1308
1309                 let mut encoded_offer = Vec::new();
1310                 tlv_stream.write(&mut encoded_offer).unwrap();
1311
1312                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1313                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1314                         .build().unwrap()
1315                         .sign(payer_sign).unwrap();
1316                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1317         }
1318
1319         #[test]
1320         fn builds_offer_with_derived_signing_pubkey() {
1321                 let node_id = recipient_pubkey();
1322                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1323                 let entropy = FixedEntropy {};
1324                 let secp_ctx = Secp256k1::new();
1325
1326                 let blinded_path = BlindedPath {
1327                         introduction_node: IntroductionNode::NodeId(pubkey(40)),
1328                         blinding_point: pubkey(41),
1329                         blinded_hops: vec![
1330                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1331                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1332                         ],
1333                 };
1334
1335                 #[cfg(c_bindings)]
1336                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1337                 let offer = OfferBuilder
1338                         ::deriving_signing_pubkey(node_id, &expanded_key, &entropy, &secp_ctx)
1339                         .amount_msats(1000)
1340                         .path(blinded_path)
1341                         .build().unwrap();
1342                 assert_ne!(offer.signing_pubkey(), Some(node_id));
1343
1344                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1345                         .build().unwrap()
1346                         .sign(payer_sign).unwrap();
1347                 match invoice_request.verify(&expanded_key, &secp_ctx) {
1348                         Ok(invoice_request) => assert_eq!(invoice_request.offer_id, offer.id()),
1349                         Err(_) => panic!("unexpected error"),
1350                 }
1351
1352                 // Fails verification with altered offer field
1353                 let mut tlv_stream = offer.as_tlv_stream();
1354                 tlv_stream.amount = Some(100);
1355
1356                 let mut encoded_offer = Vec::new();
1357                 tlv_stream.write(&mut encoded_offer).unwrap();
1358
1359                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1360                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1361                         .build().unwrap()
1362                         .sign(payer_sign).unwrap();
1363                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1364
1365                 // Fails verification with altered signing pubkey
1366                 let mut tlv_stream = offer.as_tlv_stream();
1367                 let signing_pubkey = pubkey(1);
1368                 tlv_stream.node_id = Some(&signing_pubkey);
1369
1370                 let mut encoded_offer = Vec::new();
1371                 tlv_stream.write(&mut encoded_offer).unwrap();
1372
1373                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1374                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1375                         .build().unwrap()
1376                         .sign(payer_sign).unwrap();
1377                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1378         }
1379
1380         #[test]
1381         fn builds_offer_with_amount() {
1382                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1383                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1384
1385                 let offer = OfferBuilder::new(pubkey(42))
1386                         .amount_msats(1000)
1387                         .build()
1388                         .unwrap();
1389                 let tlv_stream = offer.as_tlv_stream();
1390                 assert_eq!(offer.amount(), Some(bitcoin_amount));
1391                 assert_eq!(tlv_stream.amount, Some(1000));
1392                 assert_eq!(tlv_stream.currency, None);
1393
1394                 #[cfg(not(c_bindings))]
1395                 let builder = OfferBuilder::new(pubkey(42))
1396                         .amount(currency_amount.clone());
1397                 #[cfg(c_bindings)]
1398                 let mut builder = OfferBuilder::new(pubkey(42));
1399                 #[cfg(c_bindings)]
1400                 builder.amount(currency_amount.clone());
1401                 let tlv_stream = builder.offer.as_tlv_stream();
1402                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1403                 assert_eq!(tlv_stream.amount, Some(10));
1404                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1405                 match builder.build() {
1406                         Ok(_) => panic!("expected error"),
1407                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1408                 }
1409
1410                 let offer = OfferBuilder::new(pubkey(42))
1411                         .amount(currency_amount.clone())
1412                         .amount(bitcoin_amount.clone())
1413                         .build()
1414                         .unwrap();
1415                 let tlv_stream = offer.as_tlv_stream();
1416                 assert_eq!(tlv_stream.amount, Some(1000));
1417                 assert_eq!(tlv_stream.currency, None);
1418
1419                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1420                 match OfferBuilder::new(pubkey(42)).amount(invalid_amount).build() {
1421                         Ok(_) => panic!("expected error"),
1422                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1423                 }
1424         }
1425
1426         #[test]
1427         fn builds_offer_with_description() {
1428                 let offer = OfferBuilder::new(pubkey(42))
1429                         .description("foo".into())
1430                         .build()
1431                         .unwrap();
1432                 assert_eq!(offer.description(), Some(PrintableString("foo")));
1433                 assert_eq!(offer.as_tlv_stream().description, Some(&String::from("foo")));
1434
1435                 let offer = OfferBuilder::new(pubkey(42))
1436                         .description("foo".into())
1437                         .description("bar".into())
1438                         .build()
1439                         .unwrap();
1440                 assert_eq!(offer.description(), Some(PrintableString("bar")));
1441                 assert_eq!(offer.as_tlv_stream().description, Some(&String::from("bar")));
1442
1443                 let offer = OfferBuilder::new(pubkey(42))
1444                         .amount_msats(1000)
1445                         .build()
1446                         .unwrap();
1447                 assert_eq!(offer.description(), Some(PrintableString("")));
1448                 assert_eq!(offer.as_tlv_stream().description, Some(&String::from("")));
1449         }
1450
1451         #[test]
1452         fn builds_offer_with_features() {
1453                 let offer = OfferBuilder::new(pubkey(42))
1454                         .features_unchecked(OfferFeatures::unknown())
1455                         .build()
1456                         .unwrap();
1457                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1458                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1459
1460                 let offer = OfferBuilder::new(pubkey(42))
1461                         .features_unchecked(OfferFeatures::unknown())
1462                         .features_unchecked(OfferFeatures::empty())
1463                         .build()
1464                         .unwrap();
1465                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1466                 assert_eq!(offer.as_tlv_stream().features, None);
1467         }
1468
1469         #[test]
1470         fn builds_offer_with_absolute_expiry() {
1471                 let future_expiry = Duration::from_secs(u64::max_value());
1472                 let past_expiry = Duration::from_secs(0);
1473                 let now = future_expiry - Duration::from_secs(1_000);
1474
1475                 let offer = OfferBuilder::new(pubkey(42))
1476                         .absolute_expiry(future_expiry)
1477                         .build()
1478                         .unwrap();
1479                 #[cfg(feature = "std")]
1480                 assert!(!offer.is_expired());
1481                 assert!(!offer.is_expired_no_std(now));
1482                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1483                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1484
1485                 let offer = OfferBuilder::new(pubkey(42))
1486                         .absolute_expiry(future_expiry)
1487                         .absolute_expiry(past_expiry)
1488                         .build()
1489                         .unwrap();
1490                 #[cfg(feature = "std")]
1491                 assert!(offer.is_expired());
1492                 assert!(offer.is_expired_no_std(now));
1493                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1494                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1495         }
1496
1497         #[test]
1498         fn builds_offer_with_paths() {
1499                 let paths = vec![
1500                         BlindedPath {
1501                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1502                                 blinding_point: pubkey(41),
1503                                 blinded_hops: vec![
1504                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1505                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1506                                 ],
1507                         },
1508                         BlindedPath {
1509                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1510                                 blinding_point: pubkey(41),
1511                                 blinded_hops: vec![
1512                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1513                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1514                                 ],
1515                         },
1516                 ];
1517
1518                 let offer = OfferBuilder::new(pubkey(42))
1519                         .path(paths[0].clone())
1520                         .path(paths[1].clone())
1521                         .build()
1522                         .unwrap();
1523                 let tlv_stream = offer.as_tlv_stream();
1524                 assert_eq!(offer.paths(), paths.as_slice());
1525                 assert_eq!(offer.signing_pubkey(), Some(pubkey(42)));
1526                 assert_ne!(pubkey(42), pubkey(44));
1527                 assert_eq!(tlv_stream.paths, Some(&paths));
1528                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1529         }
1530
1531         #[test]
1532         fn builds_offer_with_issuer() {
1533                 let offer = OfferBuilder::new(pubkey(42))
1534                         .issuer("foo".into())
1535                         .build()
1536                         .unwrap();
1537                 assert_eq!(offer.issuer(), Some(PrintableString("foo")));
1538                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("foo")));
1539
1540                 let offer = OfferBuilder::new(pubkey(42))
1541                         .issuer("foo".into())
1542                         .issuer("bar".into())
1543                         .build()
1544                         .unwrap();
1545                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1546                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1547         }
1548
1549         #[test]
1550         fn builds_offer_with_supported_quantity() {
1551                 let one = NonZeroU64::new(1).unwrap();
1552                 let ten = NonZeroU64::new(10).unwrap();
1553
1554                 let offer = OfferBuilder::new(pubkey(42))
1555                         .supported_quantity(Quantity::One)
1556                         .build()
1557                         .unwrap();
1558                 let tlv_stream = offer.as_tlv_stream();
1559                 assert!(!offer.expects_quantity());
1560                 assert_eq!(offer.supported_quantity(), Quantity::One);
1561                 assert_eq!(tlv_stream.quantity_max, None);
1562
1563                 let offer = OfferBuilder::new(pubkey(42))
1564                         .supported_quantity(Quantity::Unbounded)
1565                         .build()
1566                         .unwrap();
1567                 let tlv_stream = offer.as_tlv_stream();
1568                 assert!(offer.expects_quantity());
1569                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1570                 assert_eq!(tlv_stream.quantity_max, Some(0));
1571
1572                 let offer = OfferBuilder::new(pubkey(42))
1573                         .supported_quantity(Quantity::Bounded(ten))
1574                         .build()
1575                         .unwrap();
1576                 let tlv_stream = offer.as_tlv_stream();
1577                 assert!(offer.expects_quantity());
1578                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1579                 assert_eq!(tlv_stream.quantity_max, Some(10));
1580
1581                 let offer = OfferBuilder::new(pubkey(42))
1582                         .supported_quantity(Quantity::Bounded(one))
1583                         .build()
1584                         .unwrap();
1585                 let tlv_stream = offer.as_tlv_stream();
1586                 assert!(offer.expects_quantity());
1587                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1588                 assert_eq!(tlv_stream.quantity_max, Some(1));
1589
1590                 let offer = OfferBuilder::new(pubkey(42))
1591                         .supported_quantity(Quantity::Bounded(ten))
1592                         .supported_quantity(Quantity::One)
1593                         .build()
1594                         .unwrap();
1595                 let tlv_stream = offer.as_tlv_stream();
1596                 assert!(!offer.expects_quantity());
1597                 assert_eq!(offer.supported_quantity(), Quantity::One);
1598                 assert_eq!(tlv_stream.quantity_max, None);
1599         }
1600
1601         #[test]
1602         fn fails_requesting_invoice_with_unknown_required_features() {
1603                 match OfferBuilder::new(pubkey(42))
1604                         .features_unchecked(OfferFeatures::unknown())
1605                         .build().unwrap()
1606                         .request_invoice(vec![1; 32], pubkey(43))
1607                 {
1608                         Ok(_) => panic!("expected error"),
1609                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1610                 }
1611         }
1612
1613         #[test]
1614         fn parses_offer_with_chains() {
1615                 let offer = OfferBuilder::new(pubkey(42))
1616                         .chain(Network::Bitcoin)
1617                         .chain(Network::Testnet)
1618                         .build()
1619                         .unwrap();
1620                 if let Err(e) = offer.to_string().parse::<Offer>() {
1621                         panic!("error parsing offer: {:?}", e);
1622                 }
1623         }
1624
1625         #[test]
1626         fn parses_offer_with_amount() {
1627                 let offer = OfferBuilder::new(pubkey(42))
1628                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1629                         .build()
1630                         .unwrap();
1631                 if let Err(e) = offer.to_string().parse::<Offer>() {
1632                         panic!("error parsing offer: {:?}", e);
1633                 }
1634
1635                 let mut tlv_stream = offer.as_tlv_stream();
1636                 tlv_stream.amount = Some(1000);
1637                 tlv_stream.currency = Some(b"USD");
1638
1639                 let mut encoded_offer = Vec::new();
1640                 tlv_stream.write(&mut encoded_offer).unwrap();
1641
1642                 if let Err(e) = Offer::try_from(encoded_offer) {
1643                         panic!("error parsing offer: {:?}", e);
1644                 }
1645
1646                 let mut tlv_stream = offer.as_tlv_stream();
1647                 tlv_stream.amount = None;
1648                 tlv_stream.currency = Some(b"USD");
1649
1650                 let mut encoded_offer = Vec::new();
1651                 tlv_stream.write(&mut encoded_offer).unwrap();
1652
1653                 match Offer::try_from(encoded_offer) {
1654                         Ok(_) => panic!("expected error"),
1655                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1656                 }
1657
1658                 let mut tlv_stream = offer.as_tlv_stream();
1659                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1660                 tlv_stream.currency = None;
1661
1662                 let mut encoded_offer = Vec::new();
1663                 tlv_stream.write(&mut encoded_offer).unwrap();
1664
1665                 match Offer::try_from(encoded_offer) {
1666                         Ok(_) => panic!("expected error"),
1667                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1668                 }
1669         }
1670
1671         #[test]
1672         fn parses_offer_with_description() {
1673                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1674                 if let Err(e) = offer.to_string().parse::<Offer>() {
1675                         panic!("error parsing offer: {:?}", e);
1676                 }
1677
1678                 let offer = OfferBuilder::new(pubkey(42))
1679                         .description("foo".to_string())
1680                         .amount_msats(1000)
1681                         .build().unwrap();
1682                 if let Err(e) = offer.to_string().parse::<Offer>() {
1683                         panic!("error parsing offer: {:?}", e);
1684                 }
1685
1686                 let mut tlv_stream = offer.as_tlv_stream();
1687                 tlv_stream.description = None;
1688
1689                 let mut encoded_offer = Vec::new();
1690                 tlv_stream.write(&mut encoded_offer).unwrap();
1691
1692                 match Offer::try_from(encoded_offer) {
1693                         Ok(_) => panic!("expected error"),
1694                         Err(e) => {
1695                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1696                         },
1697                 }
1698         }
1699
1700         #[test]
1701         fn parses_offer_with_paths() {
1702                 let offer = OfferBuilder::new(pubkey(42))
1703                         .path(BlindedPath {
1704                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1705                                 blinding_point: pubkey(41),
1706                                 blinded_hops: vec![
1707                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1708                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1709                                 ],
1710                         })
1711                         .path(BlindedPath {
1712                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1713                                 blinding_point: pubkey(41),
1714                                 blinded_hops: vec![
1715                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1716                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1717                                 ],
1718                         })
1719                         .build()
1720                         .unwrap();
1721                 if let Err(e) = offer.to_string().parse::<Offer>() {
1722                         panic!("error parsing offer: {:?}", e);
1723                 }
1724
1725                 let offer = OfferBuilder::new(pubkey(42))
1726                         .path(BlindedPath {
1727                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1728                                 blinding_point: pubkey(41),
1729                                 blinded_hops: vec![
1730                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1731                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1732                                 ],
1733                         })
1734                         .clear_signing_pubkey()
1735                         .build()
1736                         .unwrap();
1737                 if let Err(e) = offer.to_string().parse::<Offer>() {
1738                         panic!("error parsing offer: {:?}", e);
1739                 }
1740
1741                 let mut builder = OfferBuilder::new(pubkey(42));
1742                 builder.offer.paths = Some(vec![]);
1743
1744                 let offer = builder.build().unwrap();
1745                 match offer.to_string().parse::<Offer>() {
1746                         Ok(_) => panic!("expected error"),
1747                         Err(e) => {
1748                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPaths));
1749                         },
1750                 }
1751         }
1752
1753         #[test]
1754         fn parses_offer_with_quantity() {
1755                 let offer = OfferBuilder::new(pubkey(42))
1756                         .supported_quantity(Quantity::One)
1757                         .build()
1758                         .unwrap();
1759                 if let Err(e) = offer.to_string().parse::<Offer>() {
1760                         panic!("error parsing offer: {:?}", e);
1761                 }
1762
1763                 let offer = OfferBuilder::new(pubkey(42))
1764                         .supported_quantity(Quantity::Unbounded)
1765                         .build()
1766                         .unwrap();
1767                 if let Err(e) = offer.to_string().parse::<Offer>() {
1768                         panic!("error parsing offer: {:?}", e);
1769                 }
1770
1771                 let offer = OfferBuilder::new(pubkey(42))
1772                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1773                         .build()
1774                         .unwrap();
1775                 if let Err(e) = offer.to_string().parse::<Offer>() {
1776                         panic!("error parsing offer: {:?}", e);
1777                 }
1778
1779                 let offer = OfferBuilder::new(pubkey(42))
1780                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1781                         .build()
1782                         .unwrap();
1783                 if let Err(e) = offer.to_string().parse::<Offer>() {
1784                         panic!("error parsing offer: {:?}", e);
1785                 }
1786         }
1787
1788         #[test]
1789         fn parses_offer_with_node_id() {
1790                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1791                 if let Err(e) = offer.to_string().parse::<Offer>() {
1792                         panic!("error parsing offer: {:?}", e);
1793                 }
1794
1795                 let mut tlv_stream = offer.as_tlv_stream();
1796                 tlv_stream.node_id = None;
1797
1798                 let mut encoded_offer = Vec::new();
1799                 tlv_stream.write(&mut encoded_offer).unwrap();
1800
1801                 match Offer::try_from(encoded_offer) {
1802                         Ok(_) => panic!("expected error"),
1803                         Err(e) => {
1804                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1805                         },
1806                 }
1807         }
1808
1809         #[test]
1810         fn fails_parsing_offer_with_extra_tlv_records() {
1811                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1812
1813                 let mut encoded_offer = Vec::new();
1814                 offer.write(&mut encoded_offer).unwrap();
1815                 BigSize(80).write(&mut encoded_offer).unwrap();
1816                 BigSize(32).write(&mut encoded_offer).unwrap();
1817                 [42u8; 32].write(&mut encoded_offer).unwrap();
1818
1819                 match Offer::try_from(encoded_offer) {
1820                         Ok(_) => panic!("expected error"),
1821                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1822                 }
1823         }
1824 }
1825
1826 #[cfg(test)]
1827 mod bolt12_tests {
1828         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1829         use crate::ln::msgs::DecodeError;
1830
1831         #[test]
1832         fn parses_bech32_encoded_offers() {
1833                 let offers = [
1834                         // Minimal bolt12 offer
1835                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1836
1837                         // for testnet
1838                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1839
1840                         // for bitcoin (redundant)
1841                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1842
1843                         // for bitcoin or liquidv1
1844                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1845
1846                         // with metadata
1847                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1848
1849                         // with amount
1850                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1851
1852                         // with currency
1853                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1854
1855                         // with expiry
1856                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1857
1858                         // with issuer
1859                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1860
1861                         // with quantity
1862                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1863
1864                         // with unlimited (or unknown) quantity
1865                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1866
1867                         // with single quantity (weird but valid)
1868                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1869
1870                         // with feature
1871                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1872
1873                         // with blinded path via Bob (0x424242...), blinding 020202...
1874                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1875
1876                         // ... and with sciddir introduction node
1877                         "lno1pgx9getnwss8vetrw3hhyucs3yqqqqqqqqqqqqp2qgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqyqqqqqqqqqqqqqqqqqqqqqqqqqqqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqqgzyg3zyg3zyg3z93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1878
1879                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1880                         "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",
1881
1882                         // unknown odd field
1883                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1884                 ];
1885                 for encoded_offer in &offers {
1886                         if let Err(e) = encoded_offer.parse::<Offer>() {
1887                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1888                         }
1889                 }
1890         }
1891
1892         #[test]
1893         fn fails_parsing_bech32_encoded_offers() {
1894                 // Malformed: fields out of order
1895                 assert_eq!(
1896                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1897                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1898                 );
1899
1900                 // Malformed: unknown even TLV type 78
1901                 assert_eq!(
1902                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1903                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1904                 );
1905
1906                 // Malformed: empty
1907                 assert_eq!(
1908                         "lno1".parse::<Offer>(),
1909                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1910                 );
1911
1912                 // Malformed: truncated at type
1913                 assert_eq!(
1914                         "lno1pg".parse::<Offer>(),
1915                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1916                 );
1917
1918                 // Malformed: truncated in length
1919                 assert_eq!(
1920                         "lno1pt7s".parse::<Offer>(),
1921                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1922                 );
1923
1924                 // Malformed: truncated after length
1925                 assert_eq!(
1926                         "lno1pgpq".parse::<Offer>(),
1927                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1928                 );
1929
1930                 // Malformed: truncated in description
1931                 assert_eq!(
1932                         "lno1pgpyz".parse::<Offer>(),
1933                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1934                 );
1935
1936                 // Malformed: invalid offer_chains length
1937                 assert_eq!(
1938                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1939                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1940                 );
1941
1942                 // Malformed: truncated currency UTF-8
1943                 assert_eq!(
1944                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1945                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1946                 );
1947
1948                 // Malformed: invalid currency UTF-8
1949                 assert_eq!(
1950                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1951                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1952                 );
1953
1954                 // Malformed: truncated description UTF-8
1955                 assert_eq!(
1956                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1957                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1958                 );
1959
1960                 // Malformed: invalid description UTF-8
1961                 assert_eq!(
1962                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1963                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1964                 );
1965
1966                 // Malformed: truncated offer_paths
1967                 assert_eq!(
1968                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1969                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1970                 );
1971
1972                 // Malformed: zero num_hops in blinded_path
1973                 assert_eq!(
1974                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1975                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1976                 );
1977
1978                 // Malformed: truncated onionmsg_hop in blinded_path
1979                 assert_eq!(
1980                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1981                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1982                 );
1983
1984                 // Malformed: bad first_node_id in blinded_path
1985                 assert_eq!(
1986                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1987                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1988                 );
1989
1990                 // Malformed: bad blinding in blinded_path
1991                 assert_eq!(
1992                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1993                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1994                 );
1995
1996                 // Malformed: bad blinded_node_id in onionmsg_hop
1997                 assert_eq!(
1998                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1999                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
2000                 );
2001
2002                 // Malformed: truncated issuer UTF-8
2003                 assert_eq!(
2004                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
2005                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2006                 );
2007
2008                 // Malformed: invalid issuer UTF-8
2009                 assert_eq!(
2010                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
2011                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2012                 );
2013
2014                 // Malformed: invalid offer_node_id
2015                 assert_eq!(
2016                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
2017                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2018                 );
2019
2020                 // Contains type >= 80
2021                 assert_eq!(
2022                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
2023                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2024                 );
2025
2026                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
2027                 // Contains unknown feature 22
2028                 assert!(
2029                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
2030                 );
2031
2032                 // Missing offer_description
2033                 assert_eq!(
2034                         // TODO: Match the spec once it is updated.
2035                         "lno1pqpq86qkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>(),
2036                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
2037                 );
2038
2039                 // Missing offer_node_id"
2040                 assert_eq!(
2041                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
2042                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
2043                 );
2044         }
2045 }