_ 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(crate) fn clear_paths(mut self) -> Self {
 343                 self.offer.paths = None;
 344                 self
 345         }
 346
 347         pub(super) fn build_unchecked(self) -> Offer {
 348                 self.build_without_checks()
 349         }
 350 }
 351
 352 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 353 ///
 354 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 355 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 356 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 357 ///
 358 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 359 /// latter.
 360 ///
 361 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 362 ///
 363 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 364 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 365 #[derive(Clone, Debug)]
 366 #[cfg_attr(test, derive(PartialEq))]
 367 pub struct Offer {
 368         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 369         // fields.
 370         pub(super) bytes: Vec<u8>,
 371         pub(super) contents: OfferContents,
 372 }
 373
 374 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 375 /// [`Bolt12Invoice`].
 376 ///
 377 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 378 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 379 #[derive(Clone, Debug)]
 380 #[cfg_attr(test, derive(PartialEq))]
 381 pub(super) struct OfferContents {
 382         chains: Option<Vec<ChainHash>>,
 383         metadata: Option<Metadata>,
 384         amount: Option<Amount>,
 385         description: String,
 386         features: OfferFeatures,
 387         absolute_expiry: Option<Duration>,
 388         issuer: Option<String>,
 389         paths: Option<Vec<BlindedPath>>,
 390         supported_quantity: Quantity,
 391         signing_pubkey: PublicKey,
 392 }
 393
 394 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 395         // TODO: Return a slice once ChainHash has constants.
 396         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 397         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 398         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 399         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 400         /// for the selected chain.
 401         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 402                 $contents.chains()
 403         }
 404
 405         // TODO: Link to corresponding method in `InvoiceRequest`.
 406         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 407         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 408         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 409                 $contents.metadata()
 410         }
 411
 412         /// The minimum amount required for a successful payment of a single item.
 413         pub fn amount(&$self) -> Option<&$crate::offers::offer::Amount> {
 414                 $contents.amount()
 415         }
 416
 417         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 418         /// but with the caveat that it has not been verified in any way.
 419         pub fn description(&$self) -> $crate::util::string::PrintableString {
 420                 $contents.description()
 421         }
 422
 423         /// Features pertaining to the offer.
 424         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 425                 &$contents.features()
 426         }
 427
 428         /// Duration since the Unix epoch when an invoice should no longer be requested.
 429         ///
 430         /// If `None`, the offer does not expire.
 431         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 432                 $contents.absolute_expiry()
 433         }
 434
 435         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 436         /// displayed to the user but with the caveat that it has not been verified in any way.
 437         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 438                 $contents.issuer()
 439         }
 440
 441         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 442         /// recipient privacy by obfuscating its node id.
 443         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 444                 $contents.paths()
 445         }
 446
 447         /// The quantity of items supported.
 448         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 449                 $contents.supported_quantity()
 450         }
 451
 452         /// The public key used by the recipient to sign invoices.
 453         pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
 454                 $contents.signing_pubkey()
 455         }
 456 } }
 457
 458 impl Offer {
 459         offer_accessors!(self, self.contents);
 460
 461         pub(super) fn implied_chain(&self) -> ChainHash {
 462                 self.contents.implied_chain()
 463         }
 464
 465         /// Returns whether the given chain is supported by the offer.
 466         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 467                 self.contents.supports_chain(chain)
 468         }
 469
 470         /// Whether the offer has expired.
 471         #[cfg(feature = "std")]
 472         pub fn is_expired(&self) -> bool {
 473                 self.contents.is_expired()
 474         }
 475
 476         /// Whether the offer has expired given the duration since the Unix epoch.
 477         pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 478                 self.contents.is_expired_no_std(duration_since_epoch)
 479         }
 480
 481         /// Returns whether the given quantity is valid for the offer.
 482         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 483                 self.contents.is_valid_quantity(quantity)
 484         }
 485
 486         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 487         ///
 488         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 489         pub fn expects_quantity(&self) -> bool {
 490                 self.contents.expects_quantity()
 491         }
 492
 493         /// Similar to [`Offer::request_invoice`] except it:
 494         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 495         ///   request,
 496         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 497         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 498         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 499         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 500         ///   be used when sending the payment for the requested invoice.
 501         ///
 502         /// Useful to protect the sender's privacy.
 503         ///
 504         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 505         ///
 506         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 507         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 508         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 509         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 510         pub fn request_invoice_deriving_payer_id<'a, 'b, ES: Deref, T: secp256k1::Signing>(
 511                 &'a self, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>,
 512                 payment_id: PaymentId
 513         ) -> Result<InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>, Bolt12SemanticError>
 514         where
 515                 ES::Target: EntropySource,
 516         {
 517                 if self.offer_features().requires_unknown_bits() {
 518                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 519                 }
 520
 521                 Ok(InvoiceRequestBuilder::deriving_payer_id(
 522                         self, expanded_key, entropy_source, secp_ctx, payment_id
 523                 ))
 524         }
 525
 526         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 527         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 528         ///
 529         /// Useful for recurring payments using the same `payer_id` with different invoices.
 530         ///
 531         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 532         ///
 533         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 534         pub fn request_invoice_deriving_metadata<ES: Deref>(
 535                 &self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 536                 payment_id: PaymentId
 537         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError>
 538         where
 539                 ES::Target: EntropySource,
 540         {
 541                 if self.offer_features().requires_unknown_bits() {
 542                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 543                 }
 544
 545                 Ok(InvoiceRequestBuilder::deriving_metadata(
 546                         self, payer_id, expanded_key, entropy_source, payment_id
 547                 ))
 548         }
 549
 550         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 551         /// which will be reflected in the `Bolt12Invoice` response.
 552         ///
 553         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 554         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 555         /// hashing in the signature calculation.
 556         ///
 557         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 558         /// Otherwise, payments may be correlated.
 559         ///
 560         /// Errors if the offer contains unknown required features.
 561         ///
 562         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 563         ///
 564         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 565         pub fn request_invoice(
 566                 &self, metadata: Vec<u8>, payer_id: PublicKey
 567         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError> {
 568                 if self.offer_features().requires_unknown_bits() {
 569                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 570                 }
 571
 572                 Ok(InvoiceRequestBuilder::new(self, metadata, payer_id))
 573         }
 574
 575         #[cfg(test)]
 576         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 577                 self.contents.as_tlv_stream()
 578         }
 579 }
 580
 581 impl AsRef<[u8]> for Offer {
 582         fn as_ref(&self) -> &[u8] {
 583                 &self.bytes
 584         }
 585 }
 586
 587 impl OfferContents {
 588         pub fn chains(&self) -> Vec<ChainHash> {
 589                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 590         }
 591
 592         pub fn implied_chain(&self) -> ChainHash {
 593                 ChainHash::using_genesis_block(Network::Bitcoin)
 594         }
 595
 596         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 597                 self.chains().contains(&chain)
 598         }
 599
 600         pub fn metadata(&self) -> Option<&Vec<u8>> {
 601                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 602         }
 603
 604         pub fn amount(&self) -> Option<&Amount> {
 605                 self.amount.as_ref()
 606         }
 607
 608         pub fn description(&self) -> PrintableString {
 609                 PrintableString(&self.description)
 610         }
 611
 612         pub fn features(&self) -> &OfferFeatures {
 613                 &self.features
 614         }
 615
 616         pub fn absolute_expiry(&self) -> Option<Duration> {
 617                 self.absolute_expiry
 618         }
 619
 620         #[cfg(feature = "std")]
 621         pub(super) fn is_expired(&self) -> bool {
 622                 SystemTime::UNIX_EPOCH
 623                         .elapsed()
 624                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 625                         .unwrap_or(false)
 626         }
 627
 628         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 629                 self.absolute_expiry
 630                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 631                         .unwrap_or(false)
 632         }
 633
 634         pub fn issuer(&self) -> Option<PrintableString> {
 635                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 636         }
 637
 638         pub fn paths(&self) -> &[BlindedPath] {
 639                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 640         }
 641
 642         pub(super) fn check_amount_msats_for_quantity(
 643                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 644         ) -> Result<(), Bolt12SemanticError> {
 645                 let offer_amount_msats = match self.amount {
 646                         None => 0,
 647                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 648                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 649                 };
 650
 651                 if !self.expects_quantity() || quantity.is_some() {
 652                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 653                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 654                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 655
 656                         if amount_msats < expected_amount_msats {
 657                                 return Err(Bolt12SemanticError::InsufficientAmount);
 658                         }
 659
 660                         if amount_msats > MAX_VALUE_MSAT {
 661                                 return Err(Bolt12SemanticError::InvalidAmount);
 662                         }
 663                 }
 664
 665                 Ok(())
 666         }
 667
 668         pub fn supported_quantity(&self) -> Quantity {
 669                 self.supported_quantity
 670         }
 671
 672         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 673                 let expects_quantity = self.expects_quantity();
 674                 match quantity {
 675                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 676                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 677                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 678                                 Err(Bolt12SemanticError::InvalidQuantity)
 679                         },
 680                         _ => Ok(()),
 681                 }
 682         }
 683
 684         fn is_valid_quantity(&self, quantity: u64) -> bool {
 685                 match self.supported_quantity {
 686                         Quantity::Bounded(n) => quantity <= n.get(),
 687                         Quantity::Unbounded => quantity > 0,
 688                         Quantity::One => quantity == 1,
 689                 }
 690         }
 691
 692         fn expects_quantity(&self) -> bool {
 693                 match self.supported_quantity {
 694                         Quantity::Bounded(_) => true,
 695                         Quantity::Unbounded => true,
 696                         Quantity::One => false,
 697                 }
 698         }
 699
 700         pub(super) fn signing_pubkey(&self) -> PublicKey {
 701                 self.signing_pubkey
 702         }
 703
 704         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 705         pub(super) fn verify<T: secp256k1::Signing>(
 706                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 707         ) -> Result<Option<KeyPair>, ()> {
 708                 match self.metadata() {
 709                         Some(metadata) => {
 710                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 711                                         match record.r#type {
 712                                                 OFFER_METADATA_TYPE => false,
 713                                                 OFFER_NODE_ID_TYPE => {
 714                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 715                                                 },
 716                                                 _ => true,
 717                                         }
 718                                 });
 719                                 signer::verify_recipient_metadata(
 720                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
 721                                 )
 722                         },
 723                         None => Err(()),
 724                 }
 725         }
 726
 727         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 728                 let (currency, amount) = match &self.amount {
 729                         None => (None, None),
 730                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 731                         Some(Amount::Currency { iso4217_code, amount }) => (
 732                                 Some(iso4217_code), Some(*amount)
 733                         ),
 734                 };
 735
 736                 let features = {
 737                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 738                 };
 739
 740                 OfferTlvStreamRef {
 741                         chains: self.chains.as_ref(),
 742                         metadata: self.metadata(),
 743                         currency,
 744                         amount,
 745                         description: Some(&self.description),
 746                         features,
 747                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 748                         paths: self.paths.as_ref(),
 749                         issuer: self.issuer.as_ref(),
 750                         quantity_max: self.supported_quantity.to_tlv_record(),
 751                         node_id: Some(&self.signing_pubkey),
 752                 }
 753         }
 754 }
 755
 756 impl Writeable for Offer {
 757         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 758                 WithoutLength(&self.bytes).write(writer)
 759         }
 760 }
 761
 762 impl Writeable for OfferContents {
 763         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 764                 self.as_tlv_stream().write(writer)
 765         }
 766 }
 767
 768 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 769 /// another currency.
 770 #[derive(Clone, Debug, PartialEq)]
 771 pub enum Amount {
 772         /// An amount of bitcoin.
 773         Bitcoin {
 774                 /// The amount in millisatoshi.
 775                 amount_msats: u64,
 776         },
 777         /// An amount of currency specified using ISO 4712.
 778         Currency {
 779                 /// The currency that the amount is denominated in.
 780                 iso4217_code: CurrencyCode,
 781                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 782                 amount: u64,
 783         },
 784 }
 785
 786 /// An ISO 4712 three-letter currency code (e.g., USD).
 787 pub type CurrencyCode = [u8; 3];
 788
 789 /// Quantity of items supported by an [`Offer`].
 790 #[derive(Clone, Copy, Debug, PartialEq)]
 791 pub enum Quantity {
 792         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
 793         /// but is limited (e.g., because of per customer or inventory limits).
 794         ///
 795         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
 796         /// is supported.
 797         Bounded(NonZeroU64),
 798         /// One or more items. Use when more than one item can be requested without any limit.
 799         Unbounded,
 800         /// Only one item. Use when only a single item can be requested.
 801         One,
 802 }
 803
 804 impl Quantity {
 805         fn to_tlv_record(&self) -> Option<u64> {
 806                 match self {
 807                         Quantity::Bounded(n) => Some(n.get()),
 808                         Quantity::Unbounded => Some(0),
 809                         Quantity::One => None,
 810                 }
 811         }
 812 }
 813
 814 /// Valid type range for offer TLV records.
 815 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
 816
 817 /// TLV record type for [`Offer::metadata`].
 818 const OFFER_METADATA_TYPE: u64 = 4;
 819
 820 /// TLV record type for [`Offer::signing_pubkey`].
 821 const OFFER_NODE_ID_TYPE: u64 = 22;
 822
 823 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
 824         (2, chains: (Vec<ChainHash>, WithoutLength)),
 825         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
 826         (6, currency: CurrencyCode),
 827         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 828         (10, description: (String, WithoutLength)),
 829         (12, features: (OfferFeatures, WithoutLength)),
 830         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 831         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 832         (18, issuer: (String, WithoutLength)),
 833         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 834         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
 835 });
 836
 837 impl Bech32Encode for Offer {
 838         const BECH32_HRP: &'static str = "lno";
 839 }
 840
 841 impl FromStr for Offer {
 842         type Err = Bolt12ParseError;
 843
 844         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 845                 Self::from_bech32_str(s)
 846         }
 847 }
 848
 849 impl TryFrom<Vec<u8>> for Offer {
 850         type Error = Bolt12ParseError;
 851
 852         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 853                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
 854                 let ParsedMessage { bytes, tlv_stream } = offer;
 855                 let contents = OfferContents::try_from(tlv_stream)?;
 856                 Ok(Offer { bytes, contents })
 857         }
 858 }
 859
 860 impl TryFrom<OfferTlvStream> for OfferContents {
 861         type Error = Bolt12SemanticError;
 862
 863         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 864                 let OfferTlvStream {
 865                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 866                         issuer, quantity_max, node_id,
 867                 } = tlv_stream;
 868
 869                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
 870
 871                 let amount = match (currency, amount) {
 872                         (None, None) => None,
 873                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
 874                                 return Err(Bolt12SemanticError::InvalidAmount);
 875                         },
 876                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 877                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
 878                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
 879                 };
 880
 881                 let description = match description {
 882                         None => return Err(Bolt12SemanticError::MissingDescription),
 883                         Some(description) => description,
 884                 };
 885
 886                 let features = features.unwrap_or_else(OfferFeatures::empty);
 887
 888                 let absolute_expiry = absolute_expiry
 889                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
 890
 891                 let supported_quantity = match quantity_max {
 892                         None => Quantity::One,
 893                         Some(0) => Quantity::Unbounded,
 894                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
 895                 };
 896
 897                 let signing_pubkey = match node_id {
 898                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 899                         Some(node_id) => node_id,
 900                 };
 901
 902                 Ok(OfferContents {
 903                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
 904                         supported_quantity, signing_pubkey,
 905                 })
 906         }
 907 }
 908
 909 impl core::fmt::Display for Offer {
 910         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 911                 self.fmt_bech32_str(f)
 912         }
 913 }
 914
 915 #[cfg(test)]
 916 mod tests {
 917         use super::{Amount, Offer, OfferBuilder, OfferTlvStreamRef, Quantity};
 918
 919         use bitcoin::blockdata::constants::ChainHash;
 920         use bitcoin::network::constants::Network;
 921         use bitcoin::secp256k1::Secp256k1;
 922         use core::convert::TryFrom;
 923         use core::num::NonZeroU64;
 924         use core::time::Duration;
 925         use crate::blinded_path::{BlindedHop, BlindedPath};
 926         use crate::sign::KeyMaterial;
 927         use crate::ln::features::OfferFeatures;
 928         use crate::ln::inbound_payment::ExpandedKey;
 929         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 930         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 931         use crate::offers::test_utils::*;
 932         use crate::util::ser::{BigSize, Writeable};
 933         use crate::util::string::PrintableString;
 934
 935         #[test]
 936         fn builds_offer_with_defaults() {
 937                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
 938
 939                 let mut buffer = Vec::new();
 940                 offer.write(&mut buffer).unwrap();
 941
 942                 assert_eq!(offer.bytes, buffer.as_slice());
 943                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
 944                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
 945                 assert_eq!(offer.metadata(), None);
 946                 assert_eq!(offer.amount(), None);
 947                 assert_eq!(offer.description(), PrintableString("foo"));
 948                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
 949                 assert_eq!(offer.absolute_expiry(), None);
 950                 #[cfg(feature = "std")]
 951                 assert!(!offer.is_expired());
 952                 assert_eq!(offer.paths(), &[]);
 953                 assert_eq!(offer.issuer(), None);
 954                 assert_eq!(offer.supported_quantity(), Quantity::One);
 955                 assert_eq!(offer.signing_pubkey(), pubkey(42));
 956
 957                 assert_eq!(
 958                         offer.as_tlv_stream(),
 959                         OfferTlvStreamRef {
 960                                 chains: None,
 961                                 metadata: None,
 962                                 currency: None,
 963                                 amount: None,
 964                                 description: Some(&String::from("foo")),
 965                                 features: None,
 966                                 absolute_expiry: None,
 967                                 paths: None,
 968                                 issuer: None,
 969                                 quantity_max: None,
 970                                 node_id: Some(&pubkey(42)),
 971                         },
 972                 );
 973
 974                 if let Err(e) = Offer::try_from(buffer) {
 975                         panic!("error parsing offer: {:?}", e);
 976                 }
 977         }
 978
 979         #[test]
 980         fn builds_offer_with_chains() {
 981                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 982                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 983
 984                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 985                         .chain(Network::Bitcoin)
 986                         .build()
 987                         .unwrap();
 988                 assert!(offer.supports_chain(mainnet));
 989                 assert_eq!(offer.chains(), vec![mainnet]);
 990                 assert_eq!(offer.as_tlv_stream().chains, None);
 991
 992                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 993                         .chain(Network::Testnet)
 994                         .build()
 995                         .unwrap();
 996                 assert!(offer.supports_chain(testnet));
 997                 assert_eq!(offer.chains(), vec![testnet]);
 998                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
 999
1000                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1001                         .chain(Network::Testnet)
1002                         .chain(Network::Testnet)
1003                         .build()
1004                         .unwrap();
1005                 assert!(offer.supports_chain(testnet));
1006                 assert_eq!(offer.chains(), vec![testnet]);
1007                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1008
1009                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1010                         .chain(Network::Bitcoin)
1011                         .chain(Network::Testnet)
1012                         .build()
1013                         .unwrap();
1014                 assert!(offer.supports_chain(mainnet));
1015                 assert!(offer.supports_chain(testnet));
1016                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1017                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1018         }
1019
1020         #[test]
1021         fn builds_offer_with_metadata() {
1022                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1023                         .metadata(vec![42; 32]).unwrap()
1024                         .build()
1025                         .unwrap();
1026                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1027                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1028
1029                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1030                         .metadata(vec![42; 32]).unwrap()
1031                         .metadata(vec![43; 32]).unwrap()
1032                         .build()
1033                         .unwrap();
1034                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1035                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1036         }
1037
1038         #[test]
1039         fn builds_offer_with_metadata_derived() {
1040                 let desc = "foo".to_string();
1041                 let node_id = recipient_pubkey();
1042                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1043                 let entropy = FixedEntropy {};
1044                 let secp_ctx = Secp256k1::new();
1045
1046                 let offer = OfferBuilder
1047                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1048                         .amount_msats(1000)
1049                         .build().unwrap();
1050                 assert_eq!(offer.signing_pubkey(), node_id);
1051
1052                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1053                         .build().unwrap()
1054                         .sign(payer_sign).unwrap();
1055                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1056
1057                 // Fails verification with altered offer field
1058                 let mut tlv_stream = offer.as_tlv_stream();
1059                 tlv_stream.amount = Some(100);
1060
1061                 let mut encoded_offer = Vec::new();
1062                 tlv_stream.write(&mut encoded_offer).unwrap();
1063
1064                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1065                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1066                         .build().unwrap()
1067                         .sign(payer_sign).unwrap();
1068                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1069
1070                 // Fails verification with altered metadata
1071                 let mut tlv_stream = offer.as_tlv_stream();
1072                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1073                 tlv_stream.metadata = Some(&metadata);
1074
1075                 let mut encoded_offer = Vec::new();
1076                 tlv_stream.write(&mut encoded_offer).unwrap();
1077
1078                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1079                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1080                         .build().unwrap()
1081                         .sign(payer_sign).unwrap();
1082                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1083         }
1084
1085         #[test]
1086         fn builds_offer_with_derived_signing_pubkey() {
1087                 let desc = "foo".to_string();
1088                 let node_id = recipient_pubkey();
1089                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1090                 let entropy = FixedEntropy {};
1091                 let secp_ctx = Secp256k1::new();
1092
1093                 let blinded_path = BlindedPath {
1094                         introduction_node_id: pubkey(40),
1095                         blinding_point: pubkey(41),
1096                         blinded_hops: vec![
1097                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1098                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1099                         ],
1100                 };
1101
1102                 let offer = OfferBuilder
1103                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1104                         .amount_msats(1000)
1105                         .path(blinded_path)
1106                         .build().unwrap();
1107                 assert_ne!(offer.signing_pubkey(), node_id);
1108
1109                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1110                         .build().unwrap()
1111                         .sign(payer_sign).unwrap();
1112                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1113
1114                 // Fails verification with altered offer field
1115                 let mut tlv_stream = offer.as_tlv_stream();
1116                 tlv_stream.amount = Some(100);
1117
1118                 let mut encoded_offer = Vec::new();
1119                 tlv_stream.write(&mut encoded_offer).unwrap();
1120
1121                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1122                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1123                         .build().unwrap()
1124                         .sign(payer_sign).unwrap();
1125                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1126
1127                 // Fails verification with altered signing pubkey
1128                 let mut tlv_stream = offer.as_tlv_stream();
1129                 let signing_pubkey = pubkey(1);
1130                 tlv_stream.node_id = Some(&signing_pubkey);
1131
1132                 let mut encoded_offer = Vec::new();
1133                 tlv_stream.write(&mut encoded_offer).unwrap();
1134
1135                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1136                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1137                         .build().unwrap()
1138                         .sign(payer_sign).unwrap();
1139                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1140         }
1141
1142         #[test]
1143         fn builds_offer_with_amount() {
1144                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1145                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1146
1147                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1148                         .amount_msats(1000)
1149                         .build()
1150                         .unwrap();
1151                 let tlv_stream = offer.as_tlv_stream();
1152                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1153                 assert_eq!(tlv_stream.amount, Some(1000));
1154                 assert_eq!(tlv_stream.currency, None);
1155
1156                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1157                         .amount(currency_amount.clone());
1158                 let tlv_stream = builder.offer.as_tlv_stream();
1159                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1160                 assert_eq!(tlv_stream.amount, Some(10));
1161                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1162                 match builder.build() {
1163                         Ok(_) => panic!("expected error"),
1164                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1165                 }
1166
1167                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1168                         .amount(currency_amount.clone())
1169                         .amount(bitcoin_amount.clone())
1170                         .build()
1171                         .unwrap();
1172                 let tlv_stream = offer.as_tlv_stream();
1173                 assert_eq!(tlv_stream.amount, Some(1000));
1174                 assert_eq!(tlv_stream.currency, None);
1175
1176                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1177                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1178                         Ok(_) => panic!("expected error"),
1179                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1180                 }
1181         }
1182
1183         #[test]
1184         fn builds_offer_with_features() {
1185                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1186                         .features_unchecked(OfferFeatures::unknown())
1187                         .build()
1188                         .unwrap();
1189                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1190                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1191
1192                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1193                         .features_unchecked(OfferFeatures::unknown())
1194                         .features_unchecked(OfferFeatures::empty())
1195                         .build()
1196                         .unwrap();
1197                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1198                 assert_eq!(offer.as_tlv_stream().features, None);
1199         }
1200
1201         #[test]
1202         fn builds_offer_with_absolute_expiry() {
1203                 let future_expiry = Duration::from_secs(u64::max_value());
1204                 let past_expiry = Duration::from_secs(0);
1205                 let now = future_expiry - Duration::from_secs(1_000);
1206
1207                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1208                         .absolute_expiry(future_expiry)
1209                         .build()
1210                         .unwrap();
1211                 #[cfg(feature = "std")]
1212                 assert!(!offer.is_expired());
1213                 assert!(!offer.is_expired_no_std(now));
1214                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1215                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1216
1217                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1218                         .absolute_expiry(future_expiry)
1219                         .absolute_expiry(past_expiry)
1220                         .build()
1221                         .unwrap();
1222                 #[cfg(feature = "std")]
1223                 assert!(offer.is_expired());
1224                 assert!(offer.is_expired_no_std(now));
1225                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1226                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1227         }
1228
1229         #[test]
1230         fn builds_offer_with_paths() {
1231                 let paths = vec![
1232                         BlindedPath {
1233                                 introduction_node_id: pubkey(40),
1234                                 blinding_point: pubkey(41),
1235                                 blinded_hops: vec![
1236                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1237                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1238                                 ],
1239                         },
1240                         BlindedPath {
1241                                 introduction_node_id: pubkey(40),
1242                                 blinding_point: pubkey(41),
1243                                 blinded_hops: vec![
1244                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1245                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1246                                 ],
1247                         },
1248                 ];
1249
1250                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1251                         .path(paths[0].clone())
1252                         .path(paths[1].clone())
1253                         .build()
1254                         .unwrap();
1255                 let tlv_stream = offer.as_tlv_stream();
1256                 assert_eq!(offer.paths(), paths.as_slice());
1257                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1258                 assert_ne!(pubkey(42), pubkey(44));
1259                 assert_eq!(tlv_stream.paths, Some(&paths));
1260                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1261         }
1262
1263         #[test]
1264         fn builds_offer_with_issuer() {
1265                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1266                         .issuer("bar".into())
1267                         .build()
1268                         .unwrap();
1269                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1270                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1271
1272                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1273                         .issuer("bar".into())
1274                         .issuer("baz".into())
1275                         .build()
1276                         .unwrap();
1277                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1278                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1279         }
1280
1281         #[test]
1282         fn builds_offer_with_supported_quantity() {
1283                 let one = NonZeroU64::new(1).unwrap();
1284                 let ten = NonZeroU64::new(10).unwrap();
1285
1286                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1287                         .supported_quantity(Quantity::One)
1288                         .build()
1289                         .unwrap();
1290                 let tlv_stream = offer.as_tlv_stream();
1291                 assert_eq!(offer.supported_quantity(), Quantity::One);
1292                 assert_eq!(tlv_stream.quantity_max, None);
1293
1294                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1295                         .supported_quantity(Quantity::Unbounded)
1296                         .build()
1297                         .unwrap();
1298                 let tlv_stream = offer.as_tlv_stream();
1299                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1300                 assert_eq!(tlv_stream.quantity_max, Some(0));
1301
1302                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1303                         .supported_quantity(Quantity::Bounded(ten))
1304                         .build()
1305                         .unwrap();
1306                 let tlv_stream = offer.as_tlv_stream();
1307                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1308                 assert_eq!(tlv_stream.quantity_max, Some(10));
1309
1310                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1311                         .supported_quantity(Quantity::Bounded(one))
1312                         .build()
1313                         .unwrap();
1314                 let tlv_stream = offer.as_tlv_stream();
1315                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1316                 assert_eq!(tlv_stream.quantity_max, Some(1));
1317
1318                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1319                         .supported_quantity(Quantity::Bounded(ten))
1320                         .supported_quantity(Quantity::One)
1321                         .build()
1322                         .unwrap();
1323                 let tlv_stream = offer.as_tlv_stream();
1324                 assert_eq!(offer.supported_quantity(), Quantity::One);
1325                 assert_eq!(tlv_stream.quantity_max, None);
1326         }
1327
1328         #[test]
1329         fn fails_requesting_invoice_with_unknown_required_features() {
1330                 match OfferBuilder::new("foo".into(), pubkey(42))
1331                         .features_unchecked(OfferFeatures::unknown())
1332                         .build().unwrap()
1333                         .request_invoice(vec![1; 32], pubkey(43))
1334                 {
1335                         Ok(_) => panic!("expected error"),
1336                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1337                 }
1338         }
1339
1340         #[test]
1341         fn parses_offer_with_chains() {
1342                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1343                         .chain(Network::Bitcoin)
1344                         .chain(Network::Testnet)
1345                         .build()
1346                         .unwrap();
1347                 if let Err(e) = offer.to_string().parse::<Offer>() {
1348                         panic!("error parsing offer: {:?}", e);
1349                 }
1350         }
1351
1352         #[test]
1353         fn parses_offer_with_amount() {
1354                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1355                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1356                         .build()
1357                         .unwrap();
1358                 if let Err(e) = offer.to_string().parse::<Offer>() {
1359                         panic!("error parsing offer: {:?}", e);
1360                 }
1361
1362                 let mut tlv_stream = offer.as_tlv_stream();
1363                 tlv_stream.amount = Some(1000);
1364                 tlv_stream.currency = Some(b"USD");
1365
1366                 let mut encoded_offer = Vec::new();
1367                 tlv_stream.write(&mut encoded_offer).unwrap();
1368
1369                 if let Err(e) = Offer::try_from(encoded_offer) {
1370                         panic!("error parsing offer: {:?}", e);
1371                 }
1372
1373                 let mut tlv_stream = offer.as_tlv_stream();
1374                 tlv_stream.amount = None;
1375                 tlv_stream.currency = Some(b"USD");
1376
1377                 let mut encoded_offer = Vec::new();
1378                 tlv_stream.write(&mut encoded_offer).unwrap();
1379
1380                 match Offer::try_from(encoded_offer) {
1381                         Ok(_) => panic!("expected error"),
1382                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1383                 }
1384
1385                 let mut tlv_stream = offer.as_tlv_stream();
1386                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1387                 tlv_stream.currency = None;
1388
1389                 let mut encoded_offer = Vec::new();
1390                 tlv_stream.write(&mut encoded_offer).unwrap();
1391
1392                 match Offer::try_from(encoded_offer) {
1393                         Ok(_) => panic!("expected error"),
1394                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1395                 }
1396         }
1397
1398         #[test]
1399         fn parses_offer_with_description() {
1400                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1401                 if let Err(e) = offer.to_string().parse::<Offer>() {
1402                         panic!("error parsing offer: {:?}", e);
1403                 }
1404
1405                 let mut tlv_stream = offer.as_tlv_stream();
1406                 tlv_stream.description = None;
1407
1408                 let mut encoded_offer = Vec::new();
1409                 tlv_stream.write(&mut encoded_offer).unwrap();
1410
1411                 match Offer::try_from(encoded_offer) {
1412                         Ok(_) => panic!("expected error"),
1413                         Err(e) => {
1414                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1415                         },
1416                 }
1417         }
1418
1419         #[test]
1420         fn parses_offer_with_paths() {
1421                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1422                         .path(BlindedPath {
1423                                 introduction_node_id: pubkey(40),
1424                                 blinding_point: pubkey(41),
1425                                 blinded_hops: vec![
1426                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1427                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1428                                 ],
1429                         })
1430                         .path(BlindedPath {
1431                                 introduction_node_id: pubkey(40),
1432                                 blinding_point: pubkey(41),
1433                                 blinded_hops: vec![
1434                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1435                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1436                                 ],
1437                         })
1438                         .build()
1439                         .unwrap();
1440                 if let Err(e) = offer.to_string().parse::<Offer>() {
1441                         panic!("error parsing offer: {:?}", e);
1442                 }
1443
1444                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1445                 builder.offer.paths = Some(vec![]);
1446
1447                 let offer = builder.build().unwrap();
1448                 if let Err(e) = offer.to_string().parse::<Offer>() {
1449                         panic!("error parsing offer: {:?}", e);
1450                 }
1451         }
1452
1453         #[test]
1454         fn parses_offer_with_quantity() {
1455                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1456                         .supported_quantity(Quantity::One)
1457                         .build()
1458                         .unwrap();
1459                 if let Err(e) = offer.to_string().parse::<Offer>() {
1460                         panic!("error parsing offer: {:?}", e);
1461                 }
1462
1463                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1464                         .supported_quantity(Quantity::Unbounded)
1465                         .build()
1466                         .unwrap();
1467                 if let Err(e) = offer.to_string().parse::<Offer>() {
1468                         panic!("error parsing offer: {:?}", e);
1469                 }
1470
1471                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1472                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1473                         .build()
1474                         .unwrap();
1475                 if let Err(e) = offer.to_string().parse::<Offer>() {
1476                         panic!("error parsing offer: {:?}", e);
1477                 }
1478
1479                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1480                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1481                         .build()
1482                         .unwrap();
1483                 if let Err(e) = offer.to_string().parse::<Offer>() {
1484                         panic!("error parsing offer: {:?}", e);
1485                 }
1486         }
1487
1488         #[test]
1489         fn parses_offer_with_node_id() {
1490                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1491                 if let Err(e) = offer.to_string().parse::<Offer>() {
1492                         panic!("error parsing offer: {:?}", e);
1493                 }
1494
1495                 let mut tlv_stream = offer.as_tlv_stream();
1496                 tlv_stream.node_id = None;
1497
1498                 let mut encoded_offer = Vec::new();
1499                 tlv_stream.write(&mut encoded_offer).unwrap();
1500
1501                 match Offer::try_from(encoded_offer) {
1502                         Ok(_) => panic!("expected error"),
1503                         Err(e) => {
1504                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1505                         },
1506                 }
1507         }
1508
1509         #[test]
1510         fn fails_parsing_offer_with_extra_tlv_records() {
1511                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1512
1513                 let mut encoded_offer = Vec::new();
1514                 offer.write(&mut encoded_offer).unwrap();
1515                 BigSize(80).write(&mut encoded_offer).unwrap();
1516                 BigSize(32).write(&mut encoded_offer).unwrap();
1517                 [42u8; 32].write(&mut encoded_offer).unwrap();
1518
1519                 match Offer::try_from(encoded_offer) {
1520                         Ok(_) => panic!("expected error"),
1521                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1522                 }
1523         }
1524 }
1525
1526 #[cfg(test)]
1527 mod bolt12_tests {
1528         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1529         use crate::ln::msgs::DecodeError;
1530
1531         #[test]
1532         fn parses_bech32_encoded_offers() {
1533                 let offers = [
1534                         // Minimal bolt12 offer
1535                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1536
1537                         // for testnet
1538                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1539
1540                         // for bitcoin (redundant)
1541                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1542
1543                         // for bitcoin or liquidv1
1544                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1545
1546                         // with metadata
1547                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1548
1549                         // with amount
1550                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1551
1552                         // with currency
1553                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1554
1555                         // with expiry
1556                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1557
1558                         // with issuer
1559                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1560
1561                         // with quantity
1562                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1563
1564                         // with unlimited (or unknown) quantity
1565                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1566
1567                         // with single quantity (weird but valid)
1568                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1569
1570                         // with feature
1571                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1572
1573                         // with blinded path via Bob (0x424242...), blinding 020202...
1574                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1575
1576                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1577                         "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",
1578
1579                         // unknown odd field
1580                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1581                 ];
1582                 for encoded_offer in &offers {
1583                         if let Err(e) = encoded_offer.parse::<Offer>() {
1584                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1585                         }
1586                 }
1587         }
1588
1589         #[test]
1590         fn fails_parsing_bech32_encoded_offers() {
1591                 // Malformed: fields out of order
1592                 assert_eq!(
1593                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1594                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1595                 );
1596
1597                 // Malformed: unknown even TLV type 78
1598                 assert_eq!(
1599                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1600                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1601                 );
1602
1603                 // Malformed: empty
1604                 assert_eq!(
1605                         "lno1".parse::<Offer>(),
1606                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1607                 );
1608
1609                 // Malformed: truncated at type
1610                 assert_eq!(
1611                         "lno1pg".parse::<Offer>(),
1612                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1613                 );
1614
1615                 // Malformed: truncated in length
1616                 assert_eq!(
1617                         "lno1pt7s".parse::<Offer>(),
1618                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1619                 );
1620
1621                 // Malformed: truncated after length
1622                 assert_eq!(
1623                         "lno1pgpq".parse::<Offer>(),
1624                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1625                 );
1626
1627                 // Malformed: truncated in description
1628                 assert_eq!(
1629                         "lno1pgpyz".parse::<Offer>(),
1630                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1631                 );
1632
1633                 // Malformed: invalid offer_chains length
1634                 assert_eq!(
1635                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1636                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1637                 );
1638
1639                 // Malformed: truncated currency UTF-8
1640                 assert_eq!(
1641                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1642                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1643                 );
1644
1645                 // Malformed: invalid currency UTF-8
1646                 assert_eq!(
1647                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1648                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1649                 );
1650
1651                 // Malformed: truncated description UTF-8
1652                 assert_eq!(
1653                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1654                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1655                 );
1656
1657                 // Malformed: invalid description UTF-8
1658                 assert_eq!(
1659                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1660                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1661                 );
1662
1663                 // Malformed: truncated offer_paths
1664                 assert_eq!(
1665                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1666                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1667                 );
1668
1669                 // Malformed: zero num_hops in blinded_path
1670                 assert_eq!(
1671                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1672                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1673                 );
1674
1675                 // Malformed: truncated onionmsg_hop in blinded_path
1676                 assert_eq!(
1677                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1678                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1679                 );
1680
1681                 // Malformed: bad first_node_id in blinded_path
1682                 assert_eq!(
1683                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1684                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1685                 );
1686
1687                 // Malformed: bad blinding in blinded_path
1688                 assert_eq!(
1689                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1690                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1691                 );
1692
1693                 // Malformed: bad blinded_node_id in onionmsg_hop
1694                 assert_eq!(
1695                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1696                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1697                 );
1698
1699                 // Malformed: truncated issuer UTF-8
1700                 assert_eq!(
1701                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1702                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1703                 );
1704
1705                 // Malformed: invalid issuer UTF-8
1706                 assert_eq!(
1707                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1708                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1709                 );
1710
1711                 // Malformed: invalid offer_node_id
1712                 assert_eq!(
1713                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
1714                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1715                 );
1716
1717                 // Contains type >= 80
1718                 assert_eq!(
1719                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1720                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1721                 );
1722
1723                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
1724                 // Contains unknown feature 22
1725                 assert!(
1726                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
1727                 );
1728
1729                 // Missing offer_description
1730                 assert_eq!(
1731                         "lno1zcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese".parse::<Offer>(),
1732                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1733                 );
1734
1735                 // Missing offer_node_id"
1736                 assert_eq!(
1737                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
1738                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1739                 );
1740         }
1741 }