_ 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 //! ```
  17 //! extern crate bitcoin;
  18 //! extern crate core;
  19 //! extern crate lightning;
  20 //!
  21 //! use core::convert::TryFrom;
  22 //! use core::num::NonZeroU64;
  23 //! use core::time::Duration;
  24 //!
  25 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  26 //! use lightning::offers::offer::{Offer, OfferBuilder, Quantity};
  27 //! use lightning::offers::parse::Bolt12ParseError;
  28 //! use lightning::util::ser::{Readable, Writeable};
  29 //!
  30 //! # use lightning::blinded_path::BlindedPath;
  31 //! # #[cfg(feature = "std")]
  32 //! # use std::time::SystemTime;
  33 //! #
  34 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
  35 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
  36 //! #
  37 //! # #[cfg(feature = "std")]
  38 //! # fn build() -> Result<(), Bolt12ParseError> {
  39 //! let secp_ctx = Secp256k1::new();
  40 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
  41 //! let pubkey = PublicKey::from(keys);
  42 //!
  43 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
  44 //! let offer = OfferBuilder::new("coffee, large".to_string(), pubkey)
  45 //!     .amount_msats(20_000)
  46 //!     .supported_quantity(Quantity::Unbounded)
  47 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  48 //!     .issuer("Foo Bar".to_string())
  49 //!     .path(create_blinded_path())
  50 //!     .path(create_another_blinded_path())
  51 //!     .build()?;
  52 //!
  53 //! // Encode as a bech32 string for use in a QR code.
  54 //! let encoded_offer = offer.to_string();
  55 //!
  56 //! // Parse from a bech32 string after scanning from a QR code.
  57 //! let offer = encoded_offer.parse::<Offer>()?;
  58 //!
  59 //! // Encode offer as raw bytes.
  60 //! let mut bytes = Vec::new();
  61 //! offer.write(&mut bytes).unwrap();
  62 //!
  63 //! // Decode raw bytes into an offer.
  64 //! let offer = Offer::try_from(bytes)?;
  65 //! # Ok(())
  66 //! # }
  67 //! ```
  68
  69 use bitcoin::blockdata::constants::ChainHash;
  70 use bitcoin::network::constants::Network;
  71 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  72 use core::convert::TryFrom;
  73 use core::num::NonZeroU64;
  74 use core::ops::Deref;
  75 use core::str::FromStr;
  76 use core::time::Duration;
  77 use crate::sign::EntropySource;
  78 use crate::io;
  79 use crate::blinded_path::BlindedPath;
  80 use crate::ln::channelmanager::PaymentId;
  81 use crate::ln::features::OfferFeatures;
  82 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  83 use crate::ln::msgs::MAX_VALUE_MSAT;
  84 use crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder};
  85 use crate::offers::merkle::TlvStream;
  86 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
  87 use crate::offers::signer::{Metadata, MetadataMaterial, self};
  88 use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
  89 use crate::util::string::PrintableString;
  90
  91 use crate::prelude::*;
  92
  93 #[cfg(feature = "std")]
  94 use std::time::SystemTime;
  95
  96 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
  97
  98 /// Builds an [`Offer`] for the "offer to be paid" flow.
  99 ///
 100 /// See [module-level documentation] for usage.
 101 ///
 102 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 103 ///
 104 /// [module-level documentation]: self
 105 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
 106         offer: OfferContents,
 107         metadata_strategy: core::marker::PhantomData<M>,
 108         secp_ctx: Option<&'a Secp256k1<T>>,
 109 }
 110
 111 /// Indicates how [`Offer::metadata`] may be set.
 112 ///
 113 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 114 pub trait MetadataStrategy {}
 115
 116 /// [`Offer::metadata`] may be explicitly set or left empty.
 117 ///
 118 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 119 pub struct ExplicitMetadata {}
 120
 121 /// [`Offer::metadata`] will be derived.
 122 ///
 123 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 124 pub struct DerivedMetadata {}
 125
 126 impl MetadataStrategy for ExplicitMetadata {}
 127 impl MetadataStrategy for DerivedMetadata {}
 128
 129 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
 130         /// Creates a new builder for an offer setting the [`Offer::description`] and using the
 131         /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
 132         /// while the offer is valid.
 133         ///
 134         /// Use a different pubkey per offer to avoid correlating offers.
 135         pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
 136                 OfferBuilder {
 137                         offer: OfferContents {
 138                                 chains: None, metadata: None, amount: None, description,
 139                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 140                                 supported_quantity: Quantity::One, signing_pubkey,
 141                         },
 142                         metadata_strategy: core::marker::PhantomData,
 143                         secp_ctx: None,
 144                 }
 145         }
 146
 147         /// Sets the [`Offer::metadata`] to the given bytes.
 148         ///
 149         /// Successive calls to this method will override the previous setting.
 150         pub fn metadata(mut self, metadata: Vec<u8>) -> Result<Self, Bolt12SemanticError> {
 151                 self.offer.metadata = Some(Metadata::Bytes(metadata));
 152                 Ok(self)
 153         }
 154 }
 155
 156 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
 157         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
 158         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
 159         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
 160         /// provided `node_id` is used for the signing pubkey.
 161         ///
 162         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
 163         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
 164         /// [`ExpandedKey`].
 165         ///
 166         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
 167         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 168         pub fn deriving_signing_pubkey<ES: Deref>(
 169                 description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 170                 secp_ctx: &'a Secp256k1<T>
 171         ) -> Self where ES::Target: EntropySource {
 172                 let nonce = Nonce::from_entropy_source(entropy_source);
 173                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
 174                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 175                 OfferBuilder {
 176                         offer: OfferContents {
 177                                 chains: None, metadata: Some(metadata), amount: None, description,
 178                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 179                                 supported_quantity: Quantity::One, signing_pubkey: node_id,
 180                         },
 181                         metadata_strategy: core::marker::PhantomData,
 182                         secp_ctx: Some(secp_ctx),
 183                 }
 184         }
 185 }
 186
 187 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 188         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 189         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 190         ///
 191         /// See [`Offer::chains`] on how this relates to the payment currency.
 192         ///
 193         /// Successive calls to this method will add another chain hash.
 194         pub fn chain(mut self, network: Network) -> Self {
 195                 let chains = self.offer.chains.get_or_insert_with(Vec::new);
 196                 let chain = ChainHash::using_genesis_block(network);
 197                 if !chains.contains(&chain) {
 198                         chains.push(chain);
 199                 }
 200
 201                 self
 202         }
 203
 204         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 205         ///
 206         /// Successive calls to this method will override the previous setting.
 207         pub fn amount_msats(self, amount_msats: u64) -> Self {
 208                 self.amount(Amount::Bitcoin { amount_msats })
 209         }
 210
 211         /// Sets the [`Offer::amount`].
 212         ///
 213         /// Successive calls to this method will override the previous setting.
 214         pub(super) fn amount(mut self, amount: Amount) -> Self {
 215                 self.offer.amount = Some(amount);
 216                 self
 217         }
 218
 219         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 220         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 221         ///
 222         /// Successive calls to this method will override the previous setting.
 223         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 224                 self.offer.absolute_expiry = Some(absolute_expiry);
 225                 self
 226         }
 227
 228         /// Sets the [`Offer::issuer`].
 229         ///
 230         /// Successive calls to this method will override the previous setting.
 231         pub fn issuer(mut self, issuer: String) -> Self {
 232                 self.offer.issuer = Some(issuer);
 233                 self
 234         }
 235
 236         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 237         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 238         ///
 239         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 240         /// adding duplicate paths.
 241         pub fn path(mut self, path: BlindedPath) -> Self {
 242                 self.offer.paths.get_or_insert_with(Vec::new).push(path);
 243                 self
 244         }
 245
 246         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 247         /// [`Quantity::One`].
 248         ///
 249         /// Successive calls to this method will override the previous setting.
 250         pub fn supported_quantity(mut self, quantity: Quantity) -> Self {
 251                 self.offer.supported_quantity = quantity;
 252                 self
 253         }
 254
 255         /// Builds an [`Offer`] from the builder's settings.
 256         pub fn build(mut self) -> Result<Offer, Bolt12SemanticError> {
 257                 match self.offer.amount {
 258                         Some(Amount::Bitcoin { amount_msats }) => {
 259                                 if amount_msats > MAX_VALUE_MSAT {
 260                                         return Err(Bolt12SemanticError::InvalidAmount);
 261                                 }
 262                         },
 263                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 264                         None => {},
 265                 }
 266
 267                 if let Some(chains) = &self.offer.chains {
 268                         if chains.len() == 1 && chains[0] == self.offer.implied_chain() {
 269                                 self.offer.chains = None;
 270                         }
 271                 }
 272
 273                 Ok(self.build_without_checks())
 274         }
 275
 276         fn build_without_checks(mut self) -> Offer {
 277                 // Create the metadata for stateless verification of an InvoiceRequest.
 278                 if let Some(mut metadata) = self.offer.metadata.take() {
 279                         if metadata.has_derivation_material() {
 280                                 if self.offer.paths.is_none() {
 281                                         metadata = metadata.without_keys();
 282                                 }
 283
 284                                 let mut tlv_stream = self.offer.as_tlv_stream();
 285                                 debug_assert_eq!(tlv_stream.metadata, None);
 286                                 tlv_stream.metadata = None;
 287                                 if metadata.derives_recipient_keys() {
 288                                         tlv_stream.node_id = None;
 289                                 }
 290
 291                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
 292                                 metadata = derived_metadata;
 293                                 if let Some(keys) = keys {
 294                                         self.offer.signing_pubkey = keys.public_key();
 295                                 }
 296                         }
 297
 298                         self.offer.metadata = Some(metadata);
 299                 }
 300
 301                 let mut bytes = Vec::new();
 302                 self.offer.write(&mut bytes).unwrap();
 303
 304                 Offer { bytes, contents: self.offer }
 305         }
 306 }
 307
 308 #[cfg(test)]
 309 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 310         fn features_unchecked(mut self, features: OfferFeatures) -> Self {
 311                 self.offer.features = features;
 312                 self
 313         }
 314
 315         pub(super) fn build_unchecked(self) -> Offer {
 316                 self.build_without_checks()
 317         }
 318 }
 319
 320 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 321 ///
 322 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 323 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 324 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 325 ///
 326 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 327 /// latter.
 328 ///
 329 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 330 ///
 331 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 332 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 333 #[derive(Clone, Debug)]
 334 #[cfg_attr(test, derive(PartialEq))]
 335 pub struct Offer {
 336         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 337         // fields.
 338         pub(super) bytes: Vec<u8>,
 339         pub(super) contents: OfferContents,
 340 }
 341
 342 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 343 /// [`Bolt12Invoice`].
 344 ///
 345 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 346 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 347 #[derive(Clone, Debug)]
 348 #[cfg_attr(test, derive(PartialEq))]
 349 pub(super) struct OfferContents {
 350         chains: Option<Vec<ChainHash>>,
 351         metadata: Option<Metadata>,
 352         amount: Option<Amount>,
 353         description: String,
 354         features: OfferFeatures,
 355         absolute_expiry: Option<Duration>,
 356         issuer: Option<String>,
 357         paths: Option<Vec<BlindedPath>>,
 358         supported_quantity: Quantity,
 359         signing_pubkey: PublicKey,
 360 }
 361
 362 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 363         // TODO: Return a slice once ChainHash has constants.
 364         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 365         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 366         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 367         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 368         /// for the selected chain.
 369         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 370                 $contents.chains()
 371         }
 372
 373         // TODO: Link to corresponding method in `InvoiceRequest`.
 374         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 375         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 376         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 377                 $contents.metadata()
 378         }
 379
 380         /// The minimum amount required for a successful payment of a single item.
 381         pub fn amount(&$self) -> Option<&$crate::offers::offer::Amount> {
 382                 $contents.amount()
 383         }
 384
 385         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 386         /// but with the caveat that it has not been verified in any way.
 387         pub fn description(&$self) -> $crate::util::string::PrintableString {
 388                 $contents.description()
 389         }
 390
 391         /// Features pertaining to the offer.
 392         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 393                 &$contents.features()
 394         }
 395
 396         /// Duration since the Unix epoch when an invoice should no longer be requested.
 397         ///
 398         /// If `None`, the offer does not expire.
 399         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 400                 $contents.absolute_expiry()
 401         }
 402
 403         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 404         /// displayed to the user but with the caveat that it has not been verified in any way.
 405         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 406                 $contents.issuer()
 407         }
 408
 409         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 410         /// recipient privacy by obfuscating its node id.
 411         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 412                 $contents.paths()
 413         }
 414
 415         /// The quantity of items supported.
 416         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 417                 $contents.supported_quantity()
 418         }
 419
 420         /// The public key used by the recipient to sign invoices.
 421         pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
 422                 $contents.signing_pubkey()
 423         }
 424 } }
 425
 426 impl Offer {
 427         offer_accessors!(self, self.contents);
 428
 429         pub(super) fn implied_chain(&self) -> ChainHash {
 430                 self.contents.implied_chain()
 431         }
 432
 433         /// Returns whether the given chain is supported by the offer.
 434         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 435                 self.contents.supports_chain(chain)
 436         }
 437
 438         /// Whether the offer has expired.
 439         #[cfg(feature = "std")]
 440         pub fn is_expired(&self) -> bool {
 441                 self.contents.is_expired()
 442         }
 443
 444         /// Returns whether the given quantity is valid for the offer.
 445         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 446                 self.contents.is_valid_quantity(quantity)
 447         }
 448
 449         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 450         ///
 451         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 452         pub fn expects_quantity(&self) -> bool {
 453                 self.contents.expects_quantity()
 454         }
 455
 456         /// Similar to [`Offer::request_invoice`] except it:
 457         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 458         ///   request,
 459         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 460         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 461         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 462         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 463         ///   be used when sending the payment for the requested invoice.
 464         ///
 465         /// Useful to protect the sender's privacy.
 466         ///
 467         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 468         ///
 469         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 470         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 471         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 472         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 473         pub fn request_invoice_deriving_payer_id<'a, 'b, ES: Deref, T: secp256k1::Signing>(
 474                 &'a self, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>,
 475                 payment_id: PaymentId
 476         ) -> Result<InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>, Bolt12SemanticError>
 477         where
 478                 ES::Target: EntropySource,
 479         {
 480                 if self.offer_features().requires_unknown_bits() {
 481                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 482                 }
 483
 484                 Ok(InvoiceRequestBuilder::deriving_payer_id(
 485                         self, expanded_key, entropy_source, secp_ctx, payment_id
 486                 ))
 487         }
 488
 489         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 490         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 491         ///
 492         /// Useful for recurring payments using the same `payer_id` with different invoices.
 493         ///
 494         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 495         ///
 496         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 497         pub fn request_invoice_deriving_metadata<ES: Deref>(
 498                 &self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 499                 payment_id: PaymentId
 500         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError>
 501         where
 502                 ES::Target: EntropySource,
 503         {
 504                 if self.offer_features().requires_unknown_bits() {
 505                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 506                 }
 507
 508                 Ok(InvoiceRequestBuilder::deriving_metadata(
 509                         self, payer_id, expanded_key, entropy_source, payment_id
 510                 ))
 511         }
 512
 513         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 514         /// which will be reflected in the `Bolt12Invoice` response.
 515         ///
 516         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 517         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 518         /// hashing in the signature calculation.
 519         ///
 520         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 521         /// Otherwise, payments may be correlated.
 522         ///
 523         /// Errors if the offer contains unknown required features.
 524         ///
 525         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 526         ///
 527         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 528         pub fn request_invoice(
 529                 &self, metadata: Vec<u8>, payer_id: PublicKey
 530         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError> {
 531                 if self.offer_features().requires_unknown_bits() {
 532                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 533                 }
 534
 535                 Ok(InvoiceRequestBuilder::new(self, metadata, payer_id))
 536         }
 537
 538         #[cfg(test)]
 539         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 540                 self.contents.as_tlv_stream()
 541         }
 542 }
 543
 544 impl AsRef<[u8]> for Offer {
 545         fn as_ref(&self) -> &[u8] {
 546                 &self.bytes
 547         }
 548 }
 549
 550 impl OfferContents {
 551         pub fn chains(&self) -> Vec<ChainHash> {
 552                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 553         }
 554
 555         pub fn implied_chain(&self) -> ChainHash {
 556                 ChainHash::using_genesis_block(Network::Bitcoin)
 557         }
 558
 559         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 560                 self.chains().contains(&chain)
 561         }
 562
 563         pub fn metadata(&self) -> Option<&Vec<u8>> {
 564                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 565         }
 566
 567         pub fn amount(&self) -> Option<&Amount> {
 568                 self.amount.as_ref()
 569         }
 570
 571         pub fn description(&self) -> PrintableString {
 572                 PrintableString(&self.description)
 573         }
 574
 575         pub fn features(&self) -> &OfferFeatures {
 576                 &self.features
 577         }
 578
 579         pub fn absolute_expiry(&self) -> Option<Duration> {
 580                 self.absolute_expiry
 581         }
 582
 583         #[cfg(feature = "std")]
 584         pub(super) fn is_expired(&self) -> bool {
 585                 match self.absolute_expiry {
 586                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 587                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 588                                 Err(_) => false,
 589                         },
 590                         None => false,
 591                 }
 592         }
 593
 594         pub fn issuer(&self) -> Option<PrintableString> {
 595                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 596         }
 597
 598         pub fn paths(&self) -> &[BlindedPath] {
 599                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 600         }
 601
 602         pub(super) fn check_amount_msats_for_quantity(
 603                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 604         ) -> Result<(), Bolt12SemanticError> {
 605                 let offer_amount_msats = match self.amount {
 606                         None => 0,
 607                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 608                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 609                 };
 610
 611                 if !self.expects_quantity() || quantity.is_some() {
 612                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 613                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 614                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 615
 616                         if amount_msats < expected_amount_msats {
 617                                 return Err(Bolt12SemanticError::InsufficientAmount);
 618                         }
 619
 620                         if amount_msats > MAX_VALUE_MSAT {
 621                                 return Err(Bolt12SemanticError::InvalidAmount);
 622                         }
 623                 }
 624
 625                 Ok(())
 626         }
 627
 628         pub fn supported_quantity(&self) -> Quantity {
 629                 self.supported_quantity
 630         }
 631
 632         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 633                 let expects_quantity = self.expects_quantity();
 634                 match quantity {
 635                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 636                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 637                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 638                                 Err(Bolt12SemanticError::InvalidQuantity)
 639                         },
 640                         _ => Ok(()),
 641                 }
 642         }
 643
 644         fn is_valid_quantity(&self, quantity: u64) -> bool {
 645                 match self.supported_quantity {
 646                         Quantity::Bounded(n) => quantity <= n.get(),
 647                         Quantity::Unbounded => quantity > 0,
 648                         Quantity::One => quantity == 1,
 649                 }
 650         }
 651
 652         fn expects_quantity(&self) -> bool {
 653                 match self.supported_quantity {
 654                         Quantity::Bounded(_) => true,
 655                         Quantity::Unbounded => true,
 656                         Quantity::One => false,
 657                 }
 658         }
 659
 660         pub(super) fn signing_pubkey(&self) -> PublicKey {
 661                 self.signing_pubkey
 662         }
 663
 664         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 665         pub(super) fn verify<T: secp256k1::Signing>(
 666                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 667         ) -> Result<Option<KeyPair>, ()> {
 668                 match self.metadata() {
 669                         Some(metadata) => {
 670                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 671                                         match record.r#type {
 672                                                 OFFER_METADATA_TYPE => false,
 673                                                 OFFER_NODE_ID_TYPE => {
 674                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 675                                                 },
 676                                                 _ => true,
 677                                         }
 678                                 });
 679                                 signer::verify_recipient_metadata(
 680                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
 681                                 )
 682                         },
 683                         None => Err(()),
 684                 }
 685         }
 686
 687         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 688                 let (currency, amount) = match &self.amount {
 689                         None => (None, None),
 690                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 691                         Some(Amount::Currency { iso4217_code, amount }) => (
 692                                 Some(iso4217_code), Some(*amount)
 693                         ),
 694                 };
 695
 696                 let features = {
 697                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 698                 };
 699
 700                 OfferTlvStreamRef {
 701                         chains: self.chains.as_ref(),
 702                         metadata: self.metadata(),
 703                         currency,
 704                         amount,
 705                         description: Some(&self.description),
 706                         features,
 707                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 708                         paths: self.paths.as_ref(),
 709                         issuer: self.issuer.as_ref(),
 710                         quantity_max: self.supported_quantity.to_tlv_record(),
 711                         node_id: Some(&self.signing_pubkey),
 712                 }
 713         }
 714 }
 715
 716 impl Writeable for Offer {
 717         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 718                 WithoutLength(&self.bytes).write(writer)
 719         }
 720 }
 721
 722 impl Writeable for OfferContents {
 723         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 724                 self.as_tlv_stream().write(writer)
 725         }
 726 }
 727
 728 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 729 /// another currency.
 730 #[derive(Clone, Debug, PartialEq)]
 731 pub enum Amount {
 732         /// An amount of bitcoin.
 733         Bitcoin {
 734                 /// The amount in millisatoshi.
 735                 amount_msats: u64,
 736         },
 737         /// An amount of currency specified using ISO 4712.
 738         Currency {
 739                 /// The currency that the amount is denominated in.
 740                 ///
 741                 /// This is not exported to bindings users as bindings have troubles with type aliases to
 742                 /// byte arrays.
 743                 iso4217_code: CurrencyCode,
 744                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 745                 amount: u64,
 746         },
 747 }
 748
 749 /// An ISO 4712 three-letter currency code (e.g., USD).
 750 pub(crate) type CurrencyCode = [u8; 3];
 751
 752 /// Quantity of items supported by an [`Offer`].
 753 #[derive(Clone, Copy, Debug, PartialEq)]
 754 pub enum Quantity {
 755         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
 756         /// but is limited (e.g., because of per customer or inventory limits).
 757         ///
 758         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
 759         /// is supported.
 760         Bounded(/// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 761                 NonZeroU64),
 762         /// One or more items. Use when more than one item can be requested without any limit.
 763         Unbounded,
 764         /// Only one item. Use when only a single item can be requested.
 765         One,
 766 }
 767
 768 impl Quantity {
 769         fn to_tlv_record(&self) -> Option<u64> {
 770                 match self {
 771                         Quantity::Bounded(n) => Some(n.get()),
 772                         Quantity::Unbounded => Some(0),
 773                         Quantity::One => None,
 774                 }
 775         }
 776 }
 777
 778 /// Valid type range for offer TLV records.
 779 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
 780
 781 /// TLV record type for [`Offer::metadata`].
 782 const OFFER_METADATA_TYPE: u64 = 4;
 783
 784 /// TLV record type for [`Offer::signing_pubkey`].
 785 const OFFER_NODE_ID_TYPE: u64 = 22;
 786
 787 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
 788         (2, chains: (Vec<ChainHash>, WithoutLength)),
 789         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
 790         (6, currency: CurrencyCode),
 791         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 792         (10, description: (String, WithoutLength)),
 793         (12, features: (OfferFeatures, WithoutLength)),
 794         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 795         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 796         (18, issuer: (String, WithoutLength)),
 797         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 798         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
 799 });
 800
 801 impl Bech32Encode for Offer {
 802         const BECH32_HRP: &'static str = "lno";
 803 }
 804
 805 impl FromStr for Offer {
 806         type Err = Bolt12ParseError;
 807
 808         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 809                 Self::from_bech32_str(s)
 810         }
 811 }
 812
 813 impl TryFrom<Vec<u8>> for Offer {
 814         type Error = Bolt12ParseError;
 815
 816         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 817                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
 818                 let ParsedMessage { bytes, tlv_stream } = offer;
 819                 let contents = OfferContents::try_from(tlv_stream)?;
 820                 Ok(Offer { bytes, contents })
 821         }
 822 }
 823
 824 impl TryFrom<OfferTlvStream> for OfferContents {
 825         type Error = Bolt12SemanticError;
 826
 827         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 828                 let OfferTlvStream {
 829                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 830                         issuer, quantity_max, node_id,
 831                 } = tlv_stream;
 832
 833                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
 834
 835                 let amount = match (currency, amount) {
 836                         (None, None) => None,
 837                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
 838                                 return Err(Bolt12SemanticError::InvalidAmount);
 839                         },
 840                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 841                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
 842                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
 843                 };
 844
 845                 let description = match description {
 846                         None => return Err(Bolt12SemanticError::MissingDescription),
 847                         Some(description) => description,
 848                 };
 849
 850                 let features = features.unwrap_or_else(OfferFeatures::empty);
 851
 852                 let absolute_expiry = absolute_expiry
 853                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
 854
 855                 let supported_quantity = match quantity_max {
 856                         None => Quantity::One,
 857                         Some(0) => Quantity::Unbounded,
 858                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
 859                 };
 860
 861                 let signing_pubkey = match node_id {
 862                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 863                         Some(node_id) => node_id,
 864                 };
 865
 866                 Ok(OfferContents {
 867                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
 868                         supported_quantity, signing_pubkey,
 869                 })
 870         }
 871 }
 872
 873 impl core::fmt::Display for Offer {
 874         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 875                 self.fmt_bech32_str(f)
 876         }
 877 }
 878
 879 #[cfg(test)]
 880 mod tests {
 881         use super::{Amount, Offer, OfferBuilder, OfferTlvStreamRef, Quantity};
 882
 883         use bitcoin::blockdata::constants::ChainHash;
 884         use bitcoin::network::constants::Network;
 885         use bitcoin::secp256k1::Secp256k1;
 886         use core::convert::TryFrom;
 887         use core::num::NonZeroU64;
 888         use core::time::Duration;
 889         use crate::blinded_path::{BlindedHop, BlindedPath};
 890         use crate::sign::KeyMaterial;
 891         use crate::ln::features::OfferFeatures;
 892         use crate::ln::inbound_payment::ExpandedKey;
 893         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 894         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 895         use crate::offers::test_utils::*;
 896         use crate::util::ser::{BigSize, Writeable};
 897         use crate::util::string::PrintableString;
 898
 899         #[test]
 900         fn builds_offer_with_defaults() {
 901                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
 902
 903                 let mut buffer = Vec::new();
 904                 offer.write(&mut buffer).unwrap();
 905
 906                 assert_eq!(offer.bytes, buffer.as_slice());
 907                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
 908                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
 909                 assert_eq!(offer.metadata(), None);
 910                 assert_eq!(offer.amount(), None);
 911                 assert_eq!(offer.description(), PrintableString("foo"));
 912                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
 913                 assert_eq!(offer.absolute_expiry(), None);
 914                 #[cfg(feature = "std")]
 915                 assert!(!offer.is_expired());
 916                 assert_eq!(offer.paths(), &[]);
 917                 assert_eq!(offer.issuer(), None);
 918                 assert_eq!(offer.supported_quantity(), Quantity::One);
 919                 assert_eq!(offer.signing_pubkey(), pubkey(42));
 920
 921                 assert_eq!(
 922                         offer.as_tlv_stream(),
 923                         OfferTlvStreamRef {
 924                                 chains: None,
 925                                 metadata: None,
 926                                 currency: None,
 927                                 amount: None,
 928                                 description: Some(&String::from("foo")),
 929                                 features: None,
 930                                 absolute_expiry: None,
 931                                 paths: None,
 932                                 issuer: None,
 933                                 quantity_max: None,
 934                                 node_id: Some(&pubkey(42)),
 935                         },
 936                 );
 937
 938                 if let Err(e) = Offer::try_from(buffer) {
 939                         panic!("error parsing offer: {:?}", e);
 940                 }
 941         }
 942
 943         #[test]
 944         fn builds_offer_with_chains() {
 945                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 946                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 947
 948                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 949                         .chain(Network::Bitcoin)
 950                         .build()
 951                         .unwrap();
 952                 assert!(offer.supports_chain(mainnet));
 953                 assert_eq!(offer.chains(), vec![mainnet]);
 954                 assert_eq!(offer.as_tlv_stream().chains, None);
 955
 956                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 957                         .chain(Network::Testnet)
 958                         .build()
 959                         .unwrap();
 960                 assert!(offer.supports_chain(testnet));
 961                 assert_eq!(offer.chains(), vec![testnet]);
 962                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
 963
 964                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 965                         .chain(Network::Testnet)
 966                         .chain(Network::Testnet)
 967                         .build()
 968                         .unwrap();
 969                 assert!(offer.supports_chain(testnet));
 970                 assert_eq!(offer.chains(), vec![testnet]);
 971                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
 972
 973                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 974                         .chain(Network::Bitcoin)
 975                         .chain(Network::Testnet)
 976                         .build()
 977                         .unwrap();
 978                 assert!(offer.supports_chain(mainnet));
 979                 assert!(offer.supports_chain(testnet));
 980                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
 981                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
 982         }
 983
 984         #[test]
 985         fn builds_offer_with_metadata() {
 986                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 987                         .metadata(vec![42; 32]).unwrap()
 988                         .build()
 989                         .unwrap();
 990                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
 991                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
 992
 993                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 994                         .metadata(vec![42; 32]).unwrap()
 995                         .metadata(vec![43; 32]).unwrap()
 996                         .build()
 997                         .unwrap();
 998                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
 999                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1000         }
1001
1002         #[test]
1003         fn builds_offer_with_metadata_derived() {
1004                 let desc = "foo".to_string();
1005                 let node_id = recipient_pubkey();
1006                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1007                 let entropy = FixedEntropy {};
1008                 let secp_ctx = Secp256k1::new();
1009
1010                 let offer = OfferBuilder
1011                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1012                         .amount_msats(1000)
1013                         .build().unwrap();
1014                 assert_eq!(offer.signing_pubkey(), node_id);
1015
1016                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1017                         .build().unwrap()
1018                         .sign(payer_sign).unwrap();
1019                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1020
1021                 // Fails verification with altered offer field
1022                 let mut tlv_stream = offer.as_tlv_stream();
1023                 tlv_stream.amount = Some(100);
1024
1025                 let mut encoded_offer = Vec::new();
1026                 tlv_stream.write(&mut encoded_offer).unwrap();
1027
1028                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1029                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1030                         .build().unwrap()
1031                         .sign(payer_sign).unwrap();
1032                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1033
1034                 // Fails verification with altered metadata
1035                 let mut tlv_stream = offer.as_tlv_stream();
1036                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1037                 tlv_stream.metadata = Some(&metadata);
1038
1039                 let mut encoded_offer = Vec::new();
1040                 tlv_stream.write(&mut encoded_offer).unwrap();
1041
1042                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1043                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1044                         .build().unwrap()
1045                         .sign(payer_sign).unwrap();
1046                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1047         }
1048
1049         #[test]
1050         fn builds_offer_with_derived_signing_pubkey() {
1051                 let desc = "foo".to_string();
1052                 let node_id = recipient_pubkey();
1053                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1054                 let entropy = FixedEntropy {};
1055                 let secp_ctx = Secp256k1::new();
1056
1057                 let blinded_path = BlindedPath {
1058                         introduction_node_id: pubkey(40),
1059                         blinding_point: pubkey(41),
1060                         blinded_hops: vec![
1061                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1062                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1063                         ],
1064                 };
1065
1066                 let offer = OfferBuilder
1067                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1068                         .amount_msats(1000)
1069                         .path(blinded_path)
1070                         .build().unwrap();
1071                 assert_ne!(offer.signing_pubkey(), node_id);
1072
1073                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1074                         .build().unwrap()
1075                         .sign(payer_sign).unwrap();
1076                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1077
1078                 // Fails verification with altered offer field
1079                 let mut tlv_stream = offer.as_tlv_stream();
1080                 tlv_stream.amount = Some(100);
1081
1082                 let mut encoded_offer = Vec::new();
1083                 tlv_stream.write(&mut encoded_offer).unwrap();
1084
1085                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1086                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1087                         .build().unwrap()
1088                         .sign(payer_sign).unwrap();
1089                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1090
1091                 // Fails verification with altered signing pubkey
1092                 let mut tlv_stream = offer.as_tlv_stream();
1093                 let signing_pubkey = pubkey(1);
1094                 tlv_stream.node_id = Some(&signing_pubkey);
1095
1096                 let mut encoded_offer = Vec::new();
1097                 tlv_stream.write(&mut encoded_offer).unwrap();
1098
1099                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1100                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1101                         .build().unwrap()
1102                         .sign(payer_sign).unwrap();
1103                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1104         }
1105
1106         #[test]
1107         fn builds_offer_with_amount() {
1108                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1109                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1110
1111                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1112                         .amount_msats(1000)
1113                         .build()
1114                         .unwrap();
1115                 let tlv_stream = offer.as_tlv_stream();
1116                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1117                 assert_eq!(tlv_stream.amount, Some(1000));
1118                 assert_eq!(tlv_stream.currency, None);
1119
1120                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1121                         .amount(currency_amount.clone());
1122                 let tlv_stream = builder.offer.as_tlv_stream();
1123                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1124                 assert_eq!(tlv_stream.amount, Some(10));
1125                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1126                 match builder.build() {
1127                         Ok(_) => panic!("expected error"),
1128                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1129                 }
1130
1131                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1132                         .amount(currency_amount.clone())
1133                         .amount(bitcoin_amount.clone())
1134                         .build()
1135                         .unwrap();
1136                 let tlv_stream = offer.as_tlv_stream();
1137                 assert_eq!(tlv_stream.amount, Some(1000));
1138                 assert_eq!(tlv_stream.currency, None);
1139
1140                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1141                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1142                         Ok(_) => panic!("expected error"),
1143                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1144                 }
1145         }
1146
1147         #[test]
1148         fn builds_offer_with_features() {
1149                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1150                         .features_unchecked(OfferFeatures::unknown())
1151                         .build()
1152                         .unwrap();
1153                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1154                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1155
1156                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1157                         .features_unchecked(OfferFeatures::unknown())
1158                         .features_unchecked(OfferFeatures::empty())
1159                         .build()
1160                         .unwrap();
1161                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1162                 assert_eq!(offer.as_tlv_stream().features, None);
1163         }
1164
1165         #[test]
1166         fn builds_offer_with_absolute_expiry() {
1167                 let future_expiry = Duration::from_secs(u64::max_value());
1168                 let past_expiry = Duration::from_secs(0);
1169
1170                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1171                         .absolute_expiry(future_expiry)
1172                         .build()
1173                         .unwrap();
1174                 #[cfg(feature = "std")]
1175                 assert!(!offer.is_expired());
1176                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1177                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1178
1179                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1180                         .absolute_expiry(future_expiry)
1181                         .absolute_expiry(past_expiry)
1182                         .build()
1183                         .unwrap();
1184                 #[cfg(feature = "std")]
1185                 assert!(offer.is_expired());
1186                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1187                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1188         }
1189
1190         #[test]
1191         fn builds_offer_with_paths() {
1192                 let paths = vec![
1193                         BlindedPath {
1194                                 introduction_node_id: pubkey(40),
1195                                 blinding_point: pubkey(41),
1196                                 blinded_hops: vec![
1197                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1198                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1199                                 ],
1200                         },
1201                         BlindedPath {
1202                                 introduction_node_id: pubkey(40),
1203                                 blinding_point: pubkey(41),
1204                                 blinded_hops: vec![
1205                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1206                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1207                                 ],
1208                         },
1209                 ];
1210
1211                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1212                         .path(paths[0].clone())
1213                         .path(paths[1].clone())
1214                         .build()
1215                         .unwrap();
1216                 let tlv_stream = offer.as_tlv_stream();
1217                 assert_eq!(offer.paths(), paths.as_slice());
1218                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1219                 assert_ne!(pubkey(42), pubkey(44));
1220                 assert_eq!(tlv_stream.paths, Some(&paths));
1221                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1222         }
1223
1224         #[test]
1225         fn builds_offer_with_issuer() {
1226                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1227                         .issuer("bar".into())
1228                         .build()
1229                         .unwrap();
1230                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1231                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1232
1233                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1234                         .issuer("bar".into())
1235                         .issuer("baz".into())
1236                         .build()
1237                         .unwrap();
1238                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1239                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1240         }
1241
1242         #[test]
1243         fn builds_offer_with_supported_quantity() {
1244                 let one = NonZeroU64::new(1).unwrap();
1245                 let ten = NonZeroU64::new(10).unwrap();
1246
1247                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1248                         .supported_quantity(Quantity::One)
1249                         .build()
1250                         .unwrap();
1251                 let tlv_stream = offer.as_tlv_stream();
1252                 assert_eq!(offer.supported_quantity(), Quantity::One);
1253                 assert_eq!(tlv_stream.quantity_max, None);
1254
1255                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1256                         .supported_quantity(Quantity::Unbounded)
1257                         .build()
1258                         .unwrap();
1259                 let tlv_stream = offer.as_tlv_stream();
1260                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1261                 assert_eq!(tlv_stream.quantity_max, Some(0));
1262
1263                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1264                         .supported_quantity(Quantity::Bounded(ten))
1265                         .build()
1266                         .unwrap();
1267                 let tlv_stream = offer.as_tlv_stream();
1268                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1269                 assert_eq!(tlv_stream.quantity_max, Some(10));
1270
1271                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1272                         .supported_quantity(Quantity::Bounded(one))
1273                         .build()
1274                         .unwrap();
1275                 let tlv_stream = offer.as_tlv_stream();
1276                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1277                 assert_eq!(tlv_stream.quantity_max, Some(1));
1278
1279                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1280                         .supported_quantity(Quantity::Bounded(ten))
1281                         .supported_quantity(Quantity::One)
1282                         .build()
1283                         .unwrap();
1284                 let tlv_stream = offer.as_tlv_stream();
1285                 assert_eq!(offer.supported_quantity(), Quantity::One);
1286                 assert_eq!(tlv_stream.quantity_max, None);
1287         }
1288
1289         #[test]
1290         fn fails_requesting_invoice_with_unknown_required_features() {
1291                 match OfferBuilder::new("foo".into(), pubkey(42))
1292                         .features_unchecked(OfferFeatures::unknown())
1293                         .build().unwrap()
1294                         .request_invoice(vec![1; 32], pubkey(43))
1295                 {
1296                         Ok(_) => panic!("expected error"),
1297                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1298                 }
1299         }
1300
1301         #[test]
1302         fn parses_offer_with_chains() {
1303                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1304                         .chain(Network::Bitcoin)
1305                         .chain(Network::Testnet)
1306                         .build()
1307                         .unwrap();
1308                 if let Err(e) = offer.to_string().parse::<Offer>() {
1309                         panic!("error parsing offer: {:?}", e);
1310                 }
1311         }
1312
1313         #[test]
1314         fn parses_offer_with_amount() {
1315                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1316                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1317                         .build()
1318                         .unwrap();
1319                 if let Err(e) = offer.to_string().parse::<Offer>() {
1320                         panic!("error parsing offer: {:?}", e);
1321                 }
1322
1323                 let mut tlv_stream = offer.as_tlv_stream();
1324                 tlv_stream.amount = Some(1000);
1325                 tlv_stream.currency = Some(b"USD");
1326
1327                 let mut encoded_offer = Vec::new();
1328                 tlv_stream.write(&mut encoded_offer).unwrap();
1329
1330                 if let Err(e) = Offer::try_from(encoded_offer) {
1331                         panic!("error parsing offer: {:?}", e);
1332                 }
1333
1334                 let mut tlv_stream = offer.as_tlv_stream();
1335                 tlv_stream.amount = None;
1336                 tlv_stream.currency = Some(b"USD");
1337
1338                 let mut encoded_offer = Vec::new();
1339                 tlv_stream.write(&mut encoded_offer).unwrap();
1340
1341                 match Offer::try_from(encoded_offer) {
1342                         Ok(_) => panic!("expected error"),
1343                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1344                 }
1345
1346                 let mut tlv_stream = offer.as_tlv_stream();
1347                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1348                 tlv_stream.currency = None;
1349
1350                 let mut encoded_offer = Vec::new();
1351                 tlv_stream.write(&mut encoded_offer).unwrap();
1352
1353                 match Offer::try_from(encoded_offer) {
1354                         Ok(_) => panic!("expected error"),
1355                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1356                 }
1357         }
1358
1359         #[test]
1360         fn parses_offer_with_description() {
1361                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1362                 if let Err(e) = offer.to_string().parse::<Offer>() {
1363                         panic!("error parsing offer: {:?}", e);
1364                 }
1365
1366                 let mut tlv_stream = offer.as_tlv_stream();
1367                 tlv_stream.description = None;
1368
1369                 let mut encoded_offer = Vec::new();
1370                 tlv_stream.write(&mut encoded_offer).unwrap();
1371
1372                 match Offer::try_from(encoded_offer) {
1373                         Ok(_) => panic!("expected error"),
1374                         Err(e) => {
1375                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1376                         },
1377                 }
1378         }
1379
1380         #[test]
1381         fn parses_offer_with_paths() {
1382                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1383                         .path(BlindedPath {
1384                                 introduction_node_id: pubkey(40),
1385                                 blinding_point: pubkey(41),
1386                                 blinded_hops: vec![
1387                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1388                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1389                                 ],
1390                         })
1391                         .path(BlindedPath {
1392                                 introduction_node_id: pubkey(40),
1393                                 blinding_point: pubkey(41),
1394                                 blinded_hops: vec![
1395                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1396                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1397                                 ],
1398                         })
1399                         .build()
1400                         .unwrap();
1401                 if let Err(e) = offer.to_string().parse::<Offer>() {
1402                         panic!("error parsing offer: {:?}", e);
1403                 }
1404
1405                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1406                 builder.offer.paths = Some(vec![]);
1407
1408                 let offer = builder.build().unwrap();
1409                 if let Err(e) = offer.to_string().parse::<Offer>() {
1410                         panic!("error parsing offer: {:?}", e);
1411                 }
1412         }
1413
1414         #[test]
1415         fn parses_offer_with_quantity() {
1416                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1417                         .supported_quantity(Quantity::One)
1418                         .build()
1419                         .unwrap();
1420                 if let Err(e) = offer.to_string().parse::<Offer>() {
1421                         panic!("error parsing offer: {:?}", e);
1422                 }
1423
1424                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1425                         .supported_quantity(Quantity::Unbounded)
1426                         .build()
1427                         .unwrap();
1428                 if let Err(e) = offer.to_string().parse::<Offer>() {
1429                         panic!("error parsing offer: {:?}", e);
1430                 }
1431
1432                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1433                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1434                         .build()
1435                         .unwrap();
1436                 if let Err(e) = offer.to_string().parse::<Offer>() {
1437                         panic!("error parsing offer: {:?}", e);
1438                 }
1439
1440                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1441                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1442                         .build()
1443                         .unwrap();
1444                 if let Err(e) = offer.to_string().parse::<Offer>() {
1445                         panic!("error parsing offer: {:?}", e);
1446                 }
1447         }
1448
1449         #[test]
1450         fn parses_offer_with_node_id() {
1451                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1452                 if let Err(e) = offer.to_string().parse::<Offer>() {
1453                         panic!("error parsing offer: {:?}", e);
1454                 }
1455
1456                 let mut tlv_stream = offer.as_tlv_stream();
1457                 tlv_stream.node_id = None;
1458
1459                 let mut encoded_offer = Vec::new();
1460                 tlv_stream.write(&mut encoded_offer).unwrap();
1461
1462                 match Offer::try_from(encoded_offer) {
1463                         Ok(_) => panic!("expected error"),
1464                         Err(e) => {
1465                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1466                         },
1467                 }
1468         }
1469
1470         #[test]
1471         fn fails_parsing_offer_with_extra_tlv_records() {
1472                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1473
1474                 let mut encoded_offer = Vec::new();
1475                 offer.write(&mut encoded_offer).unwrap();
1476                 BigSize(80).write(&mut encoded_offer).unwrap();
1477                 BigSize(32).write(&mut encoded_offer).unwrap();
1478                 [42u8; 32].write(&mut encoded_offer).unwrap();
1479
1480                 match Offer::try_from(encoded_offer) {
1481                         Ok(_) => panic!("expected error"),
1482                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1483                 }
1484         }
1485 }
1486
1487 #[cfg(test)]
1488 mod bech32_tests {
1489         use super::{Bolt12ParseError, Offer};
1490         use bitcoin::bech32;
1491         use crate::ln::msgs::DecodeError;
1492
1493         #[test]
1494         fn encodes_offer_as_bech32_without_checksum() {
1495                 let encoded_offer = "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg";
1496                 let offer = dbg!(encoded_offer.parse::<Offer>().unwrap());
1497                 let reencoded_offer = offer.to_string();
1498                 dbg!(reencoded_offer.parse::<Offer>().unwrap());
1499                 assert_eq!(reencoded_offer, encoded_offer);
1500         }
1501
1502         #[test]
1503         fn parses_bech32_encoded_offers() {
1504                 let offers = [
1505                         // BOLT 12 test vectors
1506                         "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1507                         "l+no1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1508                         "lno1pqps7sjqpgt+yzm3qv4uxzmtsd3jjqer9wd3hy6tsw3+5k7msjzfpy7nz5yqcn+ygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd+5xvxg",
1509                         "lno1pqps7sjqpgt+ yzm3qv4uxzmtsd3jjqer9wd3hy6tsw3+  5k7msjzfpy7nz5yqcn+\nygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd+\r\n 5xvxg",
1510                 ];
1511                 for encoded_offer in &offers {
1512                         if let Err(e) = encoded_offer.parse::<Offer>() {
1513                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1514                         }
1515                 }
1516         }
1517
1518         #[test]
1519         fn fails_parsing_bech32_encoded_offers_with_invalid_continuations() {
1520                 let offers = [
1521                         // BOLT 12 test vectors
1522                         "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg+",
1523                         "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg+ ",
1524                         "+lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1525                         "+ lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1526                         "ln++o1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1527                 ];
1528                 for encoded_offer in &offers {
1529                         match encoded_offer.parse::<Offer>() {
1530                                 Ok(_) => panic!("Valid offer: {}", encoded_offer),
1531                                 Err(e) => assert_eq!(e, Bolt12ParseError::InvalidContinuation),
1532                         }
1533                 }
1534
1535         }
1536
1537         #[test]
1538         fn fails_parsing_bech32_encoded_offer_with_invalid_hrp() {
1539                 let encoded_offer = "lni1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg";
1540                 match encoded_offer.parse::<Offer>() {
1541                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1542                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidBech32Hrp),
1543                 }
1544         }
1545
1546         #[test]
1547         fn fails_parsing_bech32_encoded_offer_with_invalid_bech32_data() {
1548                 let encoded_offer = "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxo";
1549                 match encoded_offer.parse::<Offer>() {
1550                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1551                         Err(e) => assert_eq!(e, Bolt12ParseError::Bech32(bech32::Error::InvalidChar('o'))),
1552                 }
1553         }
1554
1555         #[test]
1556         fn fails_parsing_bech32_encoded_offer_with_invalid_tlv_data() {
1557                 let encoded_offer = "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxgqqqqq";
1558                 match encoded_offer.parse::<Offer>() {
1559                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1560                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1561                 }
1562         }
1563 }