_ 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("coffee, large".to_string(), pubkey)
  47 //!     .amount_msats(20_000)
  48 //!     .supported_quantity(Quantity::Unbounded)
  49 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  50 //!     .issuer("Foo Bar".to_string())
  51 //!     .path(create_blinded_path())
  52 //!     .path(create_another_blinded_path())
  53 //!     .build()?;
  54 //!
  55 //! // Encode as a bech32 string for use in a QR code.
  56 //! let encoded_offer = offer.to_string();
  57 //!
  58 //! // Parse from a bech32 string after scanning from a QR code.
  59 //! let offer = encoded_offer.parse::<Offer>()?;
  60 //!
  61 //! // Encode offer as raw bytes.
  62 //! let mut bytes = Vec::new();
  63 //! offer.write(&mut bytes).unwrap();
  64 //!
  65 //! // Decode raw bytes into an offer.
  66 //! let offer = Offer::try_from(bytes)?;
  67 //! # Ok(())
  68 //! # }
  69 //! ```
  70 //!
  71 //! # Note
  72 //!
  73 //! If constructing an [`Offer`] for use with a [`ChannelManager`], use
  74 //! [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
  75 //!
  76 //! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  77 //! [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
  78
  79 use bitcoin::blockdata::constants::ChainHash;
  80 use bitcoin::network::constants::Network;
  81 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  82 use core::convert::TryFrom;
  83 use core::num::NonZeroU64;
  84 use core::ops::Deref;
  85 use core::str::FromStr;
  86 use core::time::Duration;
  87 use crate::sign::EntropySource;
  88 use crate::io;
  89 use crate::blinded_path::BlindedPath;
  90 use crate::ln::channelmanager::PaymentId;
  91 use crate::ln::features::OfferFeatures;
  92 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  93 use crate::ln::msgs::MAX_VALUE_MSAT;
  94 use crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder};
  95 use crate::offers::merkle::TlvStream;
  96 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
  97 use crate::offers::signer::{Metadata, MetadataMaterial, self};
  98 use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
  99 use crate::util::string::PrintableString;
 100
 101 use crate::prelude::*;
 102
 103 #[cfg(feature = "std")]
 104 use std::time::SystemTime;
 105
 106 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
 107
 108 /// Builds an [`Offer`] for the "offer to be paid" flow.
 109 ///
 110 /// See [module-level documentation] for usage.
 111 ///
 112 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 113 ///
 114 /// [module-level documentation]: self
 115 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
 116         offer: OfferContents,
 117         metadata_strategy: core::marker::PhantomData<M>,
 118         secp_ctx: Option<&'a Secp256k1<T>>,
 119 }
 120
 121 /// Indicates how [`Offer::metadata`] may be set.
 122 ///
 123 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 124 pub trait MetadataStrategy {}
 125
 126 /// [`Offer::metadata`] may be explicitly set or left empty.
 127 ///
 128 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 129 pub struct ExplicitMetadata {}
 130
 131 /// [`Offer::metadata`] will be derived.
 132 ///
 133 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 134 pub struct DerivedMetadata {}
 135
 136 impl MetadataStrategy for ExplicitMetadata {}
 137 impl MetadataStrategy for DerivedMetadata {}
 138
 139 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
 140         /// Creates a new builder for an offer setting the [`Offer::description`] and using the
 141         /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
 142         /// while the offer is valid.
 143         ///
 144         /// Use a different pubkey per offer to avoid correlating offers.
 145         ///
 146         /// # Note
 147         ///
 148         /// If constructing an [`Offer`] for use with a [`ChannelManager`], use
 149         /// [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
 150         ///
 151         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 152         /// [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
 153         pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
 154                 OfferBuilder {
 155                         offer: OfferContents {
 156                                 chains: None, metadata: None, amount: None, description,
 157                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 158                                 supported_quantity: Quantity::One, signing_pubkey,
 159                         },
 160                         metadata_strategy: core::marker::PhantomData,
 161                         secp_ctx: None,
 162                 }
 163         }
 164
 165         /// Sets the [`Offer::metadata`] to the given bytes.
 166         ///
 167         /// Successive calls to this method will override the previous setting.
 168         pub fn metadata(mut self, metadata: Vec<u8>) -> Result<Self, Bolt12SemanticError> {
 169                 self.offer.metadata = Some(Metadata::Bytes(metadata));
 170                 Ok(self)
 171         }
 172 }
 173
 174 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
 175         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
 176         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
 177         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
 178         /// provided `node_id` is used for the signing pubkey.
 179         ///
 180         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
 181         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
 182         /// [`ExpandedKey`].
 183         ///
 184         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
 185         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 186         pub fn deriving_signing_pubkey<ES: Deref>(
 187                 description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 188                 secp_ctx: &'a Secp256k1<T>
 189         ) -> Self where ES::Target: EntropySource {
 190                 let nonce = Nonce::from_entropy_source(entropy_source);
 191                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
 192                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 193                 OfferBuilder {
 194                         offer: OfferContents {
 195                                 chains: None, metadata: Some(metadata), amount: None, description,
 196                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 197                                 supported_quantity: Quantity::One, signing_pubkey: node_id,
 198                         },
 199                         metadata_strategy: core::marker::PhantomData,
 200                         secp_ctx: Some(secp_ctx),
 201                 }
 202         }
 203 }
 204
 205 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 206         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 207         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 208         ///
 209         /// See [`Offer::chains`] on how this relates to the payment currency.
 210         ///
 211         /// Successive calls to this method will add another chain hash.
 212         pub fn chain(self, network: Network) -> Self {
 213                 self.chain_hash(ChainHash::using_genesis_block(network))
 214         }
 215
 216         /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
 217         /// [`Network::Bitcoin`] is assumed to be the only one supported.
 218         ///
 219         /// See [`Offer::chains`] on how this relates to the payment currency.
 220         ///
 221         /// Successive calls to this method will add another chain hash.
 222         pub(crate) fn chain_hash(mut self, chain: ChainHash) -> Self {
 223                 let chains = self.offer.chains.get_or_insert_with(Vec::new);
 224                 if !chains.contains(&chain) {
 225                         chains.push(chain);
 226                 }
 227
 228                 self
 229         }
 230
 231         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 232         ///
 233         /// Successive calls to this method will override the previous setting.
 234         pub fn amount_msats(self, amount_msats: u64) -> Self {
 235                 self.amount(Amount::Bitcoin { amount_msats })
 236         }
 237
 238         /// Sets the [`Offer::amount`].
 239         ///
 240         /// Successive calls to this method will override the previous setting.
 241         pub(super) fn amount(mut self, amount: Amount) -> Self {
 242                 self.offer.amount = Some(amount);
 243                 self
 244         }
 245
 246         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 247         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 248         ///
 249         /// Successive calls to this method will override the previous setting.
 250         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 251                 self.offer.absolute_expiry = Some(absolute_expiry);
 252                 self
 253         }
 254
 255         /// Sets the [`Offer::issuer`].
 256         ///
 257         /// Successive calls to this method will override the previous setting.
 258         pub fn issuer(mut self, issuer: String) -> Self {
 259                 self.offer.issuer = Some(issuer);
 260                 self
 261         }
 262
 263         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 264         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 265         ///
 266         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 267         /// adding duplicate paths.
 268         pub fn path(mut self, path: BlindedPath) -> Self {
 269                 self.offer.paths.get_or_insert_with(Vec::new).push(path);
 270                 self
 271         }
 272
 273         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 274         /// [`Quantity::One`].
 275         ///
 276         /// Successive calls to this method will override the previous setting.
 277         pub fn supported_quantity(mut self, quantity: Quantity) -> Self {
 278                 self.offer.supported_quantity = quantity;
 279                 self
 280         }
 281
 282         /// Builds an [`Offer`] from the builder's settings.
 283         pub fn build(mut self) -> Result<Offer, Bolt12SemanticError> {
 284                 match self.offer.amount {
 285                         Some(Amount::Bitcoin { amount_msats }) => {
 286                                 if amount_msats > MAX_VALUE_MSAT {
 287                                         return Err(Bolt12SemanticError::InvalidAmount);
 288                                 }
 289                         },
 290                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 291                         None => {},
 292                 }
 293
 294                 if let Some(chains) = &self.offer.chains {
 295                         if chains.len() == 1 && chains[0] == self.offer.implied_chain() {
 296                                 self.offer.chains = None;
 297                         }
 298                 }
 299
 300                 Ok(self.build_without_checks())
 301         }
 302
 303         fn build_without_checks(mut self) -> Offer {
 304                 // Create the metadata for stateless verification of an InvoiceRequest.
 305                 if let Some(mut metadata) = self.offer.metadata.take() {
 306                         if metadata.has_derivation_material() {
 307                                 if self.offer.paths.is_none() {
 308                                         metadata = metadata.without_keys();
 309                                 }
 310
 311                                 let mut tlv_stream = self.offer.as_tlv_stream();
 312                                 debug_assert_eq!(tlv_stream.metadata, None);
 313                                 tlv_stream.metadata = None;
 314                                 if metadata.derives_recipient_keys() {
 315                                         tlv_stream.node_id = None;
 316                                 }
 317
 318                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
 319                                 metadata = derived_metadata;
 320                                 if let Some(keys) = keys {
 321                                         self.offer.signing_pubkey = keys.public_key();
 322                                 }
 323                         }
 324
 325                         self.offer.metadata = Some(metadata);
 326                 }
 327
 328                 let mut bytes = Vec::new();
 329                 self.offer.write(&mut bytes).unwrap();
 330
 331                 Offer { bytes, contents: self.offer }
 332         }
 333 }
 334
 335 #[cfg(test)]
 336 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 337         fn features_unchecked(mut self, features: OfferFeatures) -> Self {
 338                 self.offer.features = features;
 339                 self
 340         }
 341
 342         pub(super) fn build_unchecked(self) -> Offer {
 343                 self.build_without_checks()
 344         }
 345 }
 346
 347 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 348 ///
 349 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 350 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 351 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 352 ///
 353 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 354 /// latter.
 355 ///
 356 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 357 ///
 358 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 359 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 360 #[derive(Clone, Debug)]
 361 #[cfg_attr(test, derive(PartialEq))]
 362 pub struct Offer {
 363         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 364         // fields.
 365         pub(super) bytes: Vec<u8>,
 366         pub(super) contents: OfferContents,
 367 }
 368
 369 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 370 /// [`Bolt12Invoice`].
 371 ///
 372 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 373 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 374 #[derive(Clone, Debug)]
 375 #[cfg_attr(test, derive(PartialEq))]
 376 pub(super) struct OfferContents {
 377         chains: Option<Vec<ChainHash>>,
 378         metadata: Option<Metadata>,
 379         amount: Option<Amount>,
 380         description: String,
 381         features: OfferFeatures,
 382         absolute_expiry: Option<Duration>,
 383         issuer: Option<String>,
 384         paths: Option<Vec<BlindedPath>>,
 385         supported_quantity: Quantity,
 386         signing_pubkey: PublicKey,
 387 }
 388
 389 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 390         // TODO: Return a slice once ChainHash has constants.
 391         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 392         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 393         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 394         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 395         /// for the selected chain.
 396         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 397                 $contents.chains()
 398         }
 399
 400         // TODO: Link to corresponding method in `InvoiceRequest`.
 401         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 402         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 403         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 404                 $contents.metadata()
 405         }
 406
 407         /// The minimum amount required for a successful payment of a single item.
 408         pub fn amount(&$self) -> Option<&$crate::offers::offer::Amount> {
 409                 $contents.amount()
 410         }
 411
 412         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 413         /// but with the caveat that it has not been verified in any way.
 414         pub fn description(&$self) -> $crate::util::string::PrintableString {
 415                 $contents.description()
 416         }
 417
 418         /// Features pertaining to the offer.
 419         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 420                 &$contents.features()
 421         }
 422
 423         /// Duration since the Unix epoch when an invoice should no longer be requested.
 424         ///
 425         /// If `None`, the offer does not expire.
 426         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 427                 $contents.absolute_expiry()
 428         }
 429
 430         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 431         /// displayed to the user but with the caveat that it has not been verified in any way.
 432         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 433                 $contents.issuer()
 434         }
 435
 436         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 437         /// recipient privacy by obfuscating its node id.
 438         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 439                 $contents.paths()
 440         }
 441
 442         /// The quantity of items supported.
 443         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 444                 $contents.supported_quantity()
 445         }
 446
 447         /// The public key used by the recipient to sign invoices.
 448         pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
 449                 $contents.signing_pubkey()
 450         }
 451 } }
 452
 453 impl Offer {
 454         offer_accessors!(self, self.contents);
 455
 456         pub(super) fn implied_chain(&self) -> ChainHash {
 457                 self.contents.implied_chain()
 458         }
 459
 460         /// Returns whether the given chain is supported by the offer.
 461         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 462                 self.contents.supports_chain(chain)
 463         }
 464
 465         /// Whether the offer has expired.
 466         #[cfg(feature = "std")]
 467         pub fn is_expired(&self) -> bool {
 468                 self.contents.is_expired()
 469         }
 470
 471         /// Returns whether the given quantity is valid for the offer.
 472         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 473                 self.contents.is_valid_quantity(quantity)
 474         }
 475
 476         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 477         ///
 478         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 479         pub fn expects_quantity(&self) -> bool {
 480                 self.contents.expects_quantity()
 481         }
 482
 483         /// Similar to [`Offer::request_invoice`] except it:
 484         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 485         ///   request,
 486         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 487         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 488         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 489         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 490         ///   be used when sending the payment for the requested invoice.
 491         ///
 492         /// Useful to protect the sender's privacy.
 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         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 498         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 499         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 500         pub fn request_invoice_deriving_payer_id<'a, 'b, ES: Deref, T: secp256k1::Signing>(
 501                 &'a self, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>,
 502                 payment_id: PaymentId
 503         ) -> Result<InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>, Bolt12SemanticError>
 504         where
 505                 ES::Target: EntropySource,
 506         {
 507                 if self.offer_features().requires_unknown_bits() {
 508                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 509                 }
 510
 511                 Ok(InvoiceRequestBuilder::deriving_payer_id(
 512                         self, expanded_key, entropy_source, secp_ctx, payment_id
 513                 ))
 514         }
 515
 516         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 517         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 518         ///
 519         /// Useful for recurring payments using the same `payer_id` with different invoices.
 520         ///
 521         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 522         ///
 523         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 524         pub fn request_invoice_deriving_metadata<ES: Deref>(
 525                 &self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 526                 payment_id: PaymentId
 527         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError>
 528         where
 529                 ES::Target: EntropySource,
 530         {
 531                 if self.offer_features().requires_unknown_bits() {
 532                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 533                 }
 534
 535                 Ok(InvoiceRequestBuilder::deriving_metadata(
 536                         self, payer_id, expanded_key, entropy_source, payment_id
 537                 ))
 538         }
 539
 540         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 541         /// which will be reflected in the `Bolt12Invoice` response.
 542         ///
 543         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 544         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 545         /// hashing in the signature calculation.
 546         ///
 547         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 548         /// Otherwise, payments may be correlated.
 549         ///
 550         /// Errors if the offer contains unknown required features.
 551         ///
 552         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 553         ///
 554         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 555         pub fn request_invoice(
 556                 &self, metadata: Vec<u8>, payer_id: PublicKey
 557         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError> {
 558                 if self.offer_features().requires_unknown_bits() {
 559                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 560                 }
 561
 562                 Ok(InvoiceRequestBuilder::new(self, metadata, payer_id))
 563         }
 564
 565         #[cfg(test)]
 566         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 567                 self.contents.as_tlv_stream()
 568         }
 569 }
 570
 571 impl AsRef<[u8]> for Offer {
 572         fn as_ref(&self) -> &[u8] {
 573                 &self.bytes
 574         }
 575 }
 576
 577 impl OfferContents {
 578         pub fn chains(&self) -> Vec<ChainHash> {
 579                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 580         }
 581
 582         pub fn implied_chain(&self) -> ChainHash {
 583                 ChainHash::using_genesis_block(Network::Bitcoin)
 584         }
 585
 586         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 587                 self.chains().contains(&chain)
 588         }
 589
 590         pub fn metadata(&self) -> Option<&Vec<u8>> {
 591                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 592         }
 593
 594         pub fn amount(&self) -> Option<&Amount> {
 595                 self.amount.as_ref()
 596         }
 597
 598         pub fn description(&self) -> PrintableString {
 599                 PrintableString(&self.description)
 600         }
 601
 602         pub fn features(&self) -> &OfferFeatures {
 603                 &self.features
 604         }
 605
 606         pub fn absolute_expiry(&self) -> Option<Duration> {
 607                 self.absolute_expiry
 608         }
 609
 610         #[cfg(feature = "std")]
 611         pub(super) fn is_expired(&self) -> bool {
 612                 SystemTime::UNIX_EPOCH
 613                         .elapsed()
 614                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 615                         .unwrap_or(false)
 616         }
 617
 618         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 619                 self.absolute_expiry
 620                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 621                         .unwrap_or(false)
 622         }
 623
 624         pub fn issuer(&self) -> Option<PrintableString> {
 625                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 626         }
 627
 628         pub fn paths(&self) -> &[BlindedPath] {
 629                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 630         }
 631
 632         pub(super) fn check_amount_msats_for_quantity(
 633                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 634         ) -> Result<(), Bolt12SemanticError> {
 635                 let offer_amount_msats = match self.amount {
 636                         None => 0,
 637                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 638                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 639                 };
 640
 641                 if !self.expects_quantity() || quantity.is_some() {
 642                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 643                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 644                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 645
 646                         if amount_msats < expected_amount_msats {
 647                                 return Err(Bolt12SemanticError::InsufficientAmount);
 648                         }
 649
 650                         if amount_msats > MAX_VALUE_MSAT {
 651                                 return Err(Bolt12SemanticError::InvalidAmount);
 652                         }
 653                 }
 654
 655                 Ok(())
 656         }
 657
 658         pub fn supported_quantity(&self) -> Quantity {
 659                 self.supported_quantity
 660         }
 661
 662         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 663                 let expects_quantity = self.expects_quantity();
 664                 match quantity {
 665                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 666                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 667                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 668                                 Err(Bolt12SemanticError::InvalidQuantity)
 669                         },
 670                         _ => Ok(()),
 671                 }
 672         }
 673
 674         fn is_valid_quantity(&self, quantity: u64) -> bool {
 675                 match self.supported_quantity {
 676                         Quantity::Bounded(n) => quantity <= n.get(),
 677                         Quantity::Unbounded => quantity > 0,
 678                         Quantity::One => quantity == 1,
 679                 }
 680         }
 681
 682         fn expects_quantity(&self) -> bool {
 683                 match self.supported_quantity {
 684                         Quantity::Bounded(_) => true,
 685                         Quantity::Unbounded => true,
 686                         Quantity::One => false,
 687                 }
 688         }
 689
 690         pub(super) fn signing_pubkey(&self) -> PublicKey {
 691                 self.signing_pubkey
 692         }
 693
 694         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 695         pub(super) fn verify<T: secp256k1::Signing>(
 696                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 697         ) -> Result<Option<KeyPair>, ()> {
 698                 match self.metadata() {
 699                         Some(metadata) => {
 700                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 701                                         match record.r#type {
 702                                                 OFFER_METADATA_TYPE => false,
 703                                                 OFFER_NODE_ID_TYPE => {
 704                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 705                                                 },
 706                                                 _ => true,
 707                                         }
 708                                 });
 709                                 signer::verify_recipient_metadata(
 710                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
 711                                 )
 712                         },
 713                         None => Err(()),
 714                 }
 715         }
 716
 717         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 718                 let (currency, amount) = match &self.amount {
 719                         None => (None, None),
 720                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 721                         Some(Amount::Currency { iso4217_code, amount }) => (
 722                                 Some(iso4217_code), Some(*amount)
 723                         ),
 724                 };
 725
 726                 let features = {
 727                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 728                 };
 729
 730                 OfferTlvStreamRef {
 731                         chains: self.chains.as_ref(),
 732                         metadata: self.metadata(),
 733                         currency,
 734                         amount,
 735                         description: Some(&self.description),
 736                         features,
 737                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 738                         paths: self.paths.as_ref(),
 739                         issuer: self.issuer.as_ref(),
 740                         quantity_max: self.supported_quantity.to_tlv_record(),
 741                         node_id: Some(&self.signing_pubkey),
 742                 }
 743         }
 744 }
 745
 746 impl Writeable for Offer {
 747         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 748                 WithoutLength(&self.bytes).write(writer)
 749         }
 750 }
 751
 752 impl Writeable for OfferContents {
 753         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 754                 self.as_tlv_stream().write(writer)
 755         }
 756 }
 757
 758 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 759 /// another currency.
 760 #[derive(Clone, Debug, PartialEq)]
 761 pub enum Amount {
 762         /// An amount of bitcoin.
 763         Bitcoin {
 764                 /// The amount in millisatoshi.
 765                 amount_msats: u64,
 766         },
 767         /// An amount of currency specified using ISO 4712.
 768         Currency {
 769                 /// The currency that the amount is denominated in.
 770                 iso4217_code: CurrencyCode,
 771                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 772                 amount: u64,
 773         },
 774 }
 775
 776 /// An ISO 4712 three-letter currency code (e.g., USD).
 777 pub type CurrencyCode = [u8; 3];
 778
 779 /// Quantity of items supported by an [`Offer`].
 780 #[derive(Clone, Copy, Debug, PartialEq)]
 781 pub enum Quantity {
 782         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
 783         /// but is limited (e.g., because of per customer or inventory limits).
 784         ///
 785         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
 786         /// is supported.
 787         Bounded(NonZeroU64),
 788         /// One or more items. Use when more than one item can be requested without any limit.
 789         Unbounded,
 790         /// Only one item. Use when only a single item can be requested.
 791         One,
 792 }
 793
 794 impl Quantity {
 795         fn to_tlv_record(&self) -> Option<u64> {
 796                 match self {
 797                         Quantity::Bounded(n) => Some(n.get()),
 798                         Quantity::Unbounded => Some(0),
 799                         Quantity::One => None,
 800                 }
 801         }
 802 }
 803
 804 /// Valid type range for offer TLV records.
 805 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
 806
 807 /// TLV record type for [`Offer::metadata`].
 808 const OFFER_METADATA_TYPE: u64 = 4;
 809
 810 /// TLV record type for [`Offer::signing_pubkey`].
 811 const OFFER_NODE_ID_TYPE: u64 = 22;
 812
 813 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
 814         (2, chains: (Vec<ChainHash>, WithoutLength)),
 815         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
 816         (6, currency: CurrencyCode),
 817         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 818         (10, description: (String, WithoutLength)),
 819         (12, features: (OfferFeatures, WithoutLength)),
 820         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 821         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 822         (18, issuer: (String, WithoutLength)),
 823         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 824         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
 825 });
 826
 827 impl Bech32Encode for Offer {
 828         const BECH32_HRP: &'static str = "lno";
 829 }
 830
 831 impl FromStr for Offer {
 832         type Err = Bolt12ParseError;
 833
 834         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 835                 Self::from_bech32_str(s)
 836         }
 837 }
 838
 839 impl TryFrom<Vec<u8>> for Offer {
 840         type Error = Bolt12ParseError;
 841
 842         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 843                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
 844                 let ParsedMessage { bytes, tlv_stream } = offer;
 845                 let contents = OfferContents::try_from(tlv_stream)?;
 846                 Ok(Offer { bytes, contents })
 847         }
 848 }
 849
 850 impl TryFrom<OfferTlvStream> for OfferContents {
 851         type Error = Bolt12SemanticError;
 852
 853         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 854                 let OfferTlvStream {
 855                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 856                         issuer, quantity_max, node_id,
 857                 } = tlv_stream;
 858
 859                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
 860
 861                 let amount = match (currency, amount) {
 862                         (None, None) => None,
 863                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
 864                                 return Err(Bolt12SemanticError::InvalidAmount);
 865                         },
 866                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 867                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
 868                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
 869                 };
 870
 871                 let description = match description {
 872                         None => return Err(Bolt12SemanticError::MissingDescription),
 873                         Some(description) => description,
 874                 };
 875
 876                 let features = features.unwrap_or_else(OfferFeatures::empty);
 877
 878                 let absolute_expiry = absolute_expiry
 879                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
 880
 881                 let supported_quantity = match quantity_max {
 882                         None => Quantity::One,
 883                         Some(0) => Quantity::Unbounded,
 884                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
 885                 };
 886
 887                 let signing_pubkey = match node_id {
 888                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 889                         Some(node_id) => node_id,
 890                 };
 891
 892                 Ok(OfferContents {
 893                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
 894                         supported_quantity, signing_pubkey,
 895                 })
 896         }
 897 }
 898
 899 impl core::fmt::Display for Offer {
 900         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 901                 self.fmt_bech32_str(f)
 902         }
 903 }
 904
 905 #[cfg(test)]
 906 mod tests {
 907         use super::{Amount, Offer, OfferBuilder, OfferTlvStreamRef, Quantity};
 908
 909         use bitcoin::blockdata::constants::ChainHash;
 910         use bitcoin::network::constants::Network;
 911         use bitcoin::secp256k1::Secp256k1;
 912         use core::convert::TryFrom;
 913         use core::num::NonZeroU64;
 914         use core::time::Duration;
 915         use crate::blinded_path::{BlindedHop, BlindedPath};
 916         use crate::sign::KeyMaterial;
 917         use crate::ln::features::OfferFeatures;
 918         use crate::ln::inbound_payment::ExpandedKey;
 919         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 920         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 921         use crate::offers::test_utils::*;
 922         use crate::util::ser::{BigSize, Writeable};
 923         use crate::util::string::PrintableString;
 924
 925         #[test]
 926         fn builds_offer_with_defaults() {
 927                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
 928
 929                 let mut buffer = Vec::new();
 930                 offer.write(&mut buffer).unwrap();
 931
 932                 assert_eq!(offer.bytes, buffer.as_slice());
 933                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
 934                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
 935                 assert_eq!(offer.metadata(), None);
 936                 assert_eq!(offer.amount(), None);
 937                 assert_eq!(offer.description(), PrintableString("foo"));
 938                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
 939                 assert_eq!(offer.absolute_expiry(), None);
 940                 #[cfg(feature = "std")]
 941                 assert!(!offer.is_expired());
 942                 assert_eq!(offer.paths(), &[]);
 943                 assert_eq!(offer.issuer(), None);
 944                 assert_eq!(offer.supported_quantity(), Quantity::One);
 945                 assert_eq!(offer.signing_pubkey(), pubkey(42));
 946
 947                 assert_eq!(
 948                         offer.as_tlv_stream(),
 949                         OfferTlvStreamRef {
 950                                 chains: None,
 951                                 metadata: None,
 952                                 currency: None,
 953                                 amount: None,
 954                                 description: Some(&String::from("foo")),
 955                                 features: None,
 956                                 absolute_expiry: None,
 957                                 paths: None,
 958                                 issuer: None,
 959                                 quantity_max: None,
 960                                 node_id: Some(&pubkey(42)),
 961                         },
 962                 );
 963
 964                 if let Err(e) = Offer::try_from(buffer) {
 965                         panic!("error parsing offer: {:?}", e);
 966                 }
 967         }
 968
 969         #[test]
 970         fn builds_offer_with_chains() {
 971                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 972                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 973
 974                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 975                         .chain(Network::Bitcoin)
 976                         .build()
 977                         .unwrap();
 978                 assert!(offer.supports_chain(mainnet));
 979                 assert_eq!(offer.chains(), vec![mainnet]);
 980                 assert_eq!(offer.as_tlv_stream().chains, None);
 981
 982                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 983                         .chain(Network::Testnet)
 984                         .build()
 985                         .unwrap();
 986                 assert!(offer.supports_chain(testnet));
 987                 assert_eq!(offer.chains(), vec![testnet]);
 988                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
 989
 990                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 991                         .chain(Network::Testnet)
 992                         .chain(Network::Testnet)
 993                         .build()
 994                         .unwrap();
 995                 assert!(offer.supports_chain(testnet));
 996                 assert_eq!(offer.chains(), vec![testnet]);
 997                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
 998
 999                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1000                         .chain(Network::Bitcoin)
1001                         .chain(Network::Testnet)
1002                         .build()
1003                         .unwrap();
1004                 assert!(offer.supports_chain(mainnet));
1005                 assert!(offer.supports_chain(testnet));
1006                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1007                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1008         }
1009
1010         #[test]
1011         fn builds_offer_with_metadata() {
1012                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1013                         .metadata(vec![42; 32]).unwrap()
1014                         .build()
1015                         .unwrap();
1016                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1017                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1018
1019                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1020                         .metadata(vec![42; 32]).unwrap()
1021                         .metadata(vec![43; 32]).unwrap()
1022                         .build()
1023                         .unwrap();
1024                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1025                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1026         }
1027
1028         #[test]
1029         fn builds_offer_with_metadata_derived() {
1030                 let desc = "foo".to_string();
1031                 let node_id = recipient_pubkey();
1032                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1033                 let entropy = FixedEntropy {};
1034                 let secp_ctx = Secp256k1::new();
1035
1036                 let offer = OfferBuilder
1037                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1038                         .amount_msats(1000)
1039                         .build().unwrap();
1040                 assert_eq!(offer.signing_pubkey(), node_id);
1041
1042                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1043                         .build().unwrap()
1044                         .sign(payer_sign).unwrap();
1045                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1046
1047                 // Fails verification with altered offer field
1048                 let mut tlv_stream = offer.as_tlv_stream();
1049                 tlv_stream.amount = Some(100);
1050
1051                 let mut encoded_offer = Vec::new();
1052                 tlv_stream.write(&mut encoded_offer).unwrap();
1053
1054                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1055                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1056                         .build().unwrap()
1057                         .sign(payer_sign).unwrap();
1058                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1059
1060                 // Fails verification with altered metadata
1061                 let mut tlv_stream = offer.as_tlv_stream();
1062                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1063                 tlv_stream.metadata = Some(&metadata);
1064
1065                 let mut encoded_offer = Vec::new();
1066                 tlv_stream.write(&mut encoded_offer).unwrap();
1067
1068                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1069                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1070                         .build().unwrap()
1071                         .sign(payer_sign).unwrap();
1072                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1073         }
1074
1075         #[test]
1076         fn builds_offer_with_derived_signing_pubkey() {
1077                 let desc = "foo".to_string();
1078                 let node_id = recipient_pubkey();
1079                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1080                 let entropy = FixedEntropy {};
1081                 let secp_ctx = Secp256k1::new();
1082
1083                 let blinded_path = BlindedPath {
1084                         introduction_node_id: pubkey(40),
1085                         blinding_point: pubkey(41),
1086                         blinded_hops: vec![
1087                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1088                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1089                         ],
1090                 };
1091
1092                 let offer = OfferBuilder
1093                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1094                         .amount_msats(1000)
1095                         .path(blinded_path)
1096                         .build().unwrap();
1097                 assert_ne!(offer.signing_pubkey(), node_id);
1098
1099                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1100                         .build().unwrap()
1101                         .sign(payer_sign).unwrap();
1102                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1103
1104                 // Fails verification with altered offer field
1105                 let mut tlv_stream = offer.as_tlv_stream();
1106                 tlv_stream.amount = Some(100);
1107
1108                 let mut encoded_offer = Vec::new();
1109                 tlv_stream.write(&mut encoded_offer).unwrap();
1110
1111                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1112                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1113                         .build().unwrap()
1114                         .sign(payer_sign).unwrap();
1115                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1116
1117                 // Fails verification with altered signing pubkey
1118                 let mut tlv_stream = offer.as_tlv_stream();
1119                 let signing_pubkey = pubkey(1);
1120                 tlv_stream.node_id = Some(&signing_pubkey);
1121
1122                 let mut encoded_offer = Vec::new();
1123                 tlv_stream.write(&mut encoded_offer).unwrap();
1124
1125                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1126                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1127                         .build().unwrap()
1128                         .sign(payer_sign).unwrap();
1129                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1130         }
1131
1132         #[test]
1133         fn builds_offer_with_amount() {
1134                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1135                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1136
1137                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1138                         .amount_msats(1000)
1139                         .build()
1140                         .unwrap();
1141                 let tlv_stream = offer.as_tlv_stream();
1142                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1143                 assert_eq!(tlv_stream.amount, Some(1000));
1144                 assert_eq!(tlv_stream.currency, None);
1145
1146                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1147                         .amount(currency_amount.clone());
1148                 let tlv_stream = builder.offer.as_tlv_stream();
1149                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1150                 assert_eq!(tlv_stream.amount, Some(10));
1151                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1152                 match builder.build() {
1153                         Ok(_) => panic!("expected error"),
1154                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1155                 }
1156
1157                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1158                         .amount(currency_amount.clone())
1159                         .amount(bitcoin_amount.clone())
1160                         .build()
1161                         .unwrap();
1162                 let tlv_stream = offer.as_tlv_stream();
1163                 assert_eq!(tlv_stream.amount, Some(1000));
1164                 assert_eq!(tlv_stream.currency, None);
1165
1166                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1167                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1168                         Ok(_) => panic!("expected error"),
1169                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1170                 }
1171         }
1172
1173         #[test]
1174         fn builds_offer_with_features() {
1175                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1176                         .features_unchecked(OfferFeatures::unknown())
1177                         .build()
1178                         .unwrap();
1179                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1180                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1181
1182                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1183                         .features_unchecked(OfferFeatures::unknown())
1184                         .features_unchecked(OfferFeatures::empty())
1185                         .build()
1186                         .unwrap();
1187                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1188                 assert_eq!(offer.as_tlv_stream().features, None);
1189         }
1190
1191         #[test]
1192         fn builds_offer_with_absolute_expiry() {
1193                 let future_expiry = Duration::from_secs(u64::max_value());
1194                 let past_expiry = Duration::from_secs(0);
1195
1196                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1197                         .absolute_expiry(future_expiry)
1198                         .build()
1199                         .unwrap();
1200                 #[cfg(feature = "std")]
1201                 assert!(!offer.is_expired());
1202                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1203                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1204
1205                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1206                         .absolute_expiry(future_expiry)
1207                         .absolute_expiry(past_expiry)
1208                         .build()
1209                         .unwrap();
1210                 #[cfg(feature = "std")]
1211                 assert!(offer.is_expired());
1212                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1213                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1214         }
1215
1216         #[test]
1217         fn builds_offer_with_paths() {
1218                 let paths = vec![
1219                         BlindedPath {
1220                                 introduction_node_id: pubkey(40),
1221                                 blinding_point: pubkey(41),
1222                                 blinded_hops: vec![
1223                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1224                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1225                                 ],
1226                         },
1227                         BlindedPath {
1228                                 introduction_node_id: pubkey(40),
1229                                 blinding_point: pubkey(41),
1230                                 blinded_hops: vec![
1231                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1232                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1233                                 ],
1234                         },
1235                 ];
1236
1237                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1238                         .path(paths[0].clone())
1239                         .path(paths[1].clone())
1240                         .build()
1241                         .unwrap();
1242                 let tlv_stream = offer.as_tlv_stream();
1243                 assert_eq!(offer.paths(), paths.as_slice());
1244                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1245                 assert_ne!(pubkey(42), pubkey(44));
1246                 assert_eq!(tlv_stream.paths, Some(&paths));
1247                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1248         }
1249
1250         #[test]
1251         fn builds_offer_with_issuer() {
1252                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1253                         .issuer("bar".into())
1254                         .build()
1255                         .unwrap();
1256                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1257                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1258
1259                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1260                         .issuer("bar".into())
1261                         .issuer("baz".into())
1262                         .build()
1263                         .unwrap();
1264                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1265                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1266         }
1267
1268         #[test]
1269         fn builds_offer_with_supported_quantity() {
1270                 let one = NonZeroU64::new(1).unwrap();
1271                 let ten = NonZeroU64::new(10).unwrap();
1272
1273                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1274                         .supported_quantity(Quantity::One)
1275                         .build()
1276                         .unwrap();
1277                 let tlv_stream = offer.as_tlv_stream();
1278                 assert_eq!(offer.supported_quantity(), Quantity::One);
1279                 assert_eq!(tlv_stream.quantity_max, None);
1280
1281                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1282                         .supported_quantity(Quantity::Unbounded)
1283                         .build()
1284                         .unwrap();
1285                 let tlv_stream = offer.as_tlv_stream();
1286                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1287                 assert_eq!(tlv_stream.quantity_max, Some(0));
1288
1289                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1290                         .supported_quantity(Quantity::Bounded(ten))
1291                         .build()
1292                         .unwrap();
1293                 let tlv_stream = offer.as_tlv_stream();
1294                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1295                 assert_eq!(tlv_stream.quantity_max, Some(10));
1296
1297                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1298                         .supported_quantity(Quantity::Bounded(one))
1299                         .build()
1300                         .unwrap();
1301                 let tlv_stream = offer.as_tlv_stream();
1302                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1303                 assert_eq!(tlv_stream.quantity_max, Some(1));
1304
1305                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1306                         .supported_quantity(Quantity::Bounded(ten))
1307                         .supported_quantity(Quantity::One)
1308                         .build()
1309                         .unwrap();
1310                 let tlv_stream = offer.as_tlv_stream();
1311                 assert_eq!(offer.supported_quantity(), Quantity::One);
1312                 assert_eq!(tlv_stream.quantity_max, None);
1313         }
1314
1315         #[test]
1316         fn fails_requesting_invoice_with_unknown_required_features() {
1317                 match OfferBuilder::new("foo".into(), pubkey(42))
1318                         .features_unchecked(OfferFeatures::unknown())
1319                         .build().unwrap()
1320                         .request_invoice(vec![1; 32], pubkey(43))
1321                 {
1322                         Ok(_) => panic!("expected error"),
1323                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1324                 }
1325         }
1326
1327         #[test]
1328         fn parses_offer_with_chains() {
1329                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1330                         .chain(Network::Bitcoin)
1331                         .chain(Network::Testnet)
1332                         .build()
1333                         .unwrap();
1334                 if let Err(e) = offer.to_string().parse::<Offer>() {
1335                         panic!("error parsing offer: {:?}", e);
1336                 }
1337         }
1338
1339         #[test]
1340         fn parses_offer_with_amount() {
1341                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1342                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1343                         .build()
1344                         .unwrap();
1345                 if let Err(e) = offer.to_string().parse::<Offer>() {
1346                         panic!("error parsing offer: {:?}", e);
1347                 }
1348
1349                 let mut tlv_stream = offer.as_tlv_stream();
1350                 tlv_stream.amount = Some(1000);
1351                 tlv_stream.currency = Some(b"USD");
1352
1353                 let mut encoded_offer = Vec::new();
1354                 tlv_stream.write(&mut encoded_offer).unwrap();
1355
1356                 if let Err(e) = Offer::try_from(encoded_offer) {
1357                         panic!("error parsing offer: {:?}", e);
1358                 }
1359
1360                 let mut tlv_stream = offer.as_tlv_stream();
1361                 tlv_stream.amount = None;
1362                 tlv_stream.currency = Some(b"USD");
1363
1364                 let mut encoded_offer = Vec::new();
1365                 tlv_stream.write(&mut encoded_offer).unwrap();
1366
1367                 match Offer::try_from(encoded_offer) {
1368                         Ok(_) => panic!("expected error"),
1369                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1370                 }
1371
1372                 let mut tlv_stream = offer.as_tlv_stream();
1373                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1374                 tlv_stream.currency = None;
1375
1376                 let mut encoded_offer = Vec::new();
1377                 tlv_stream.write(&mut encoded_offer).unwrap();
1378
1379                 match Offer::try_from(encoded_offer) {
1380                         Ok(_) => panic!("expected error"),
1381                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1382                 }
1383         }
1384
1385         #[test]
1386         fn parses_offer_with_description() {
1387                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1388                 if let Err(e) = offer.to_string().parse::<Offer>() {
1389                         panic!("error parsing offer: {:?}", e);
1390                 }
1391
1392                 let mut tlv_stream = offer.as_tlv_stream();
1393                 tlv_stream.description = None;
1394
1395                 let mut encoded_offer = Vec::new();
1396                 tlv_stream.write(&mut encoded_offer).unwrap();
1397
1398                 match Offer::try_from(encoded_offer) {
1399                         Ok(_) => panic!("expected error"),
1400                         Err(e) => {
1401                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1402                         },
1403                 }
1404         }
1405
1406         #[test]
1407         fn parses_offer_with_paths() {
1408                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1409                         .path(BlindedPath {
1410                                 introduction_node_id: pubkey(40),
1411                                 blinding_point: pubkey(41),
1412                                 blinded_hops: vec![
1413                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1414                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1415                                 ],
1416                         })
1417                         .path(BlindedPath {
1418                                 introduction_node_id: pubkey(40),
1419                                 blinding_point: pubkey(41),
1420                                 blinded_hops: vec![
1421                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1422                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1423                                 ],
1424                         })
1425                         .build()
1426                         .unwrap();
1427                 if let Err(e) = offer.to_string().parse::<Offer>() {
1428                         panic!("error parsing offer: {:?}", e);
1429                 }
1430
1431                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1432                 builder.offer.paths = Some(vec![]);
1433
1434                 let offer = builder.build().unwrap();
1435                 if let Err(e) = offer.to_string().parse::<Offer>() {
1436                         panic!("error parsing offer: {:?}", e);
1437                 }
1438         }
1439
1440         #[test]
1441         fn parses_offer_with_quantity() {
1442                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1443                         .supported_quantity(Quantity::One)
1444                         .build()
1445                         .unwrap();
1446                 if let Err(e) = offer.to_string().parse::<Offer>() {
1447                         panic!("error parsing offer: {:?}", e);
1448                 }
1449
1450                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1451                         .supported_quantity(Quantity::Unbounded)
1452                         .build()
1453                         .unwrap();
1454                 if let Err(e) = offer.to_string().parse::<Offer>() {
1455                         panic!("error parsing offer: {:?}", e);
1456                 }
1457
1458                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1459                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1460                         .build()
1461                         .unwrap();
1462                 if let Err(e) = offer.to_string().parse::<Offer>() {
1463                         panic!("error parsing offer: {:?}", e);
1464                 }
1465
1466                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1467                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1468                         .build()
1469                         .unwrap();
1470                 if let Err(e) = offer.to_string().parse::<Offer>() {
1471                         panic!("error parsing offer: {:?}", e);
1472                 }
1473         }
1474
1475         #[test]
1476         fn parses_offer_with_node_id() {
1477                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1478                 if let Err(e) = offer.to_string().parse::<Offer>() {
1479                         panic!("error parsing offer: {:?}", e);
1480                 }
1481
1482                 let mut tlv_stream = offer.as_tlv_stream();
1483                 tlv_stream.node_id = None;
1484
1485                 let mut encoded_offer = Vec::new();
1486                 tlv_stream.write(&mut encoded_offer).unwrap();
1487
1488                 match Offer::try_from(encoded_offer) {
1489                         Ok(_) => panic!("expected error"),
1490                         Err(e) => {
1491                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1492                         },
1493                 }
1494         }
1495
1496         #[test]
1497         fn fails_parsing_offer_with_extra_tlv_records() {
1498                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1499
1500                 let mut encoded_offer = Vec::new();
1501                 offer.write(&mut encoded_offer).unwrap();
1502                 BigSize(80).write(&mut encoded_offer).unwrap();
1503                 BigSize(32).write(&mut encoded_offer).unwrap();
1504                 [42u8; 32].write(&mut encoded_offer).unwrap();
1505
1506                 match Offer::try_from(encoded_offer) {
1507                         Ok(_) => panic!("expected error"),
1508                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1509                 }
1510         }
1511 }
1512
1513 #[cfg(test)]
1514 mod bech32_tests {
1515         use super::{Bolt12ParseError, Offer};
1516         use bitcoin::bech32;
1517         use crate::ln::msgs::DecodeError;
1518
1519         #[test]
1520         fn encodes_offer_as_bech32_without_checksum() {
1521                 let encoded_offer = "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg";
1522                 let offer = dbg!(encoded_offer.parse::<Offer>().unwrap());
1523                 let reencoded_offer = offer.to_string();
1524                 dbg!(reencoded_offer.parse::<Offer>().unwrap());
1525                 assert_eq!(reencoded_offer, encoded_offer);
1526         }
1527
1528         #[test]
1529         fn parses_bech32_encoded_offers() {
1530                 let offers = [
1531                         // BOLT 12 test vectors
1532                         "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1533                         "l+no1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1534                         "lno1pqps7sjqpgt+yzm3qv4uxzmtsd3jjqer9wd3hy6tsw3+5k7msjzfpy7nz5yqcn+ygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd+5xvxg",
1535                         "lno1pqps7sjqpgt+ yzm3qv4uxzmtsd3jjqer9wd3hy6tsw3+  5k7msjzfpy7nz5yqcn+\nygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd+\r\n 5xvxg",
1536                 ];
1537                 for encoded_offer in &offers {
1538                         if let Err(e) = encoded_offer.parse::<Offer>() {
1539                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1540                         }
1541                 }
1542         }
1543
1544         #[test]
1545         fn fails_parsing_bech32_encoded_offers_with_invalid_continuations() {
1546                 let offers = [
1547                         // BOLT 12 test vectors
1548                         "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg+",
1549                         "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg+ ",
1550                         "+lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1551                         "+ lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1552                         "ln++o1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1553                 ];
1554                 for encoded_offer in &offers {
1555                         match encoded_offer.parse::<Offer>() {
1556                                 Ok(_) => panic!("Valid offer: {}", encoded_offer),
1557                                 Err(e) => assert_eq!(e, Bolt12ParseError::InvalidContinuation),
1558                         }
1559                 }
1560
1561         }
1562
1563         #[test]
1564         fn fails_parsing_bech32_encoded_offer_with_invalid_hrp() {
1565                 let encoded_offer = "lni1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg";
1566                 match encoded_offer.parse::<Offer>() {
1567                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1568                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidBech32Hrp),
1569                 }
1570         }
1571
1572         #[test]
1573         fn fails_parsing_bech32_encoded_offer_with_invalid_bech32_data() {
1574                 let encoded_offer = "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxo";
1575                 match encoded_offer.parse::<Offer>() {
1576                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1577                         Err(e) => assert_eq!(e, Bolt12ParseError::Bech32(bech32::Error::InvalidChar('o'))),
1578                 }
1579         }
1580
1581         #[test]
1582         fn fails_parsing_bech32_encoded_offer_with_invalid_tlv_data() {
1583                 let encoded_offer = "lno1pqps7sjqpgtyzm3qv4uxzmtsd3jjqer9wd3hy6tsw35k7msjzfpy7nz5yqcnygrfdej82um5wf5k2uckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxgqqqqq";
1584                 match encoded_offer.parse::<Offer>() {
1585                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1586                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1587                 }
1588         }
1589 }