_ 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::hash::{Hash, Hasher};
  84 use core::num::NonZeroU64;
  85 use core::ops::Deref;
  86 use core::str::FromStr;
  87 use core::time::Duration;
  88 use crate::sign::EntropySource;
  89 use crate::io;
  90 use crate::blinded_path::BlindedPath;
  91 use crate::ln::channelmanager::PaymentId;
  92 use crate::ln::features::OfferFeatures;
  93 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  94 use crate::ln::msgs::MAX_VALUE_MSAT;
  95 use crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder};
  96 use crate::offers::merkle::TlvStream;
  97 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
  98 use crate::offers::signer::{Metadata, MetadataMaterial, self};
  99 use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
 100 use crate::util::string::PrintableString;
 101
 102 use crate::prelude::*;
 103
 104 #[cfg(feature = "std")]
 105 use std::time::SystemTime;
 106
 107 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
 108
 109 /// Builds an [`Offer`] for the "offer to be paid" flow.
 110 ///
 111 /// See [module-level documentation] for usage.
 112 ///
 113 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 114 ///
 115 /// [module-level documentation]: self
 116 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
 117         offer: OfferContents,
 118         metadata_strategy: core::marker::PhantomData<M>,
 119         secp_ctx: Option<&'a Secp256k1<T>>,
 120 }
 121
 122 /// Indicates how [`Offer::metadata`] may be set.
 123 ///
 124 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 125 pub trait MetadataStrategy {}
 126
 127 /// [`Offer::metadata`] may be explicitly set or left empty.
 128 ///
 129 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 130 pub struct ExplicitMetadata {}
 131
 132 /// [`Offer::metadata`] will be derived.
 133 ///
 134 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 135 pub struct DerivedMetadata {}
 136
 137 impl MetadataStrategy for ExplicitMetadata {}
 138 impl MetadataStrategy for DerivedMetadata {}
 139
 140 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
 141         /// Creates a new builder for an offer setting the [`Offer::description`] and using the
 142         /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
 143         /// while the offer is valid.
 144         ///
 145         /// Use a different pubkey per offer to avoid correlating offers.
 146         ///
 147         /// # Note
 148         ///
 149         /// If constructing an [`Offer`] for use with a [`ChannelManager`], use
 150         /// [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
 151         ///
 152         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 153         /// [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
 154         pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
 155                 OfferBuilder {
 156                         offer: OfferContents {
 157                                 chains: None, metadata: None, amount: None, description,
 158                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 159                                 supported_quantity: Quantity::One, signing_pubkey,
 160                         },
 161                         metadata_strategy: core::marker::PhantomData,
 162                         secp_ctx: None,
 163                 }
 164         }
 165
 166         /// Sets the [`Offer::metadata`] to the given bytes.
 167         ///
 168         /// Successive calls to this method will override the previous setting.
 169         pub fn metadata(mut self, metadata: Vec<u8>) -> Result<Self, Bolt12SemanticError> {
 170                 self.offer.metadata = Some(Metadata::Bytes(metadata));
 171                 Ok(self)
 172         }
 173 }
 174
 175 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
 176         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
 177         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
 178         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
 179         /// provided `node_id` is used for the signing pubkey.
 180         ///
 181         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
 182         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
 183         /// [`ExpandedKey`].
 184         ///
 185         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
 186         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 187         pub fn deriving_signing_pubkey<ES: Deref>(
 188                 description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 189                 secp_ctx: &'a Secp256k1<T>
 190         ) -> Self where ES::Target: EntropySource {
 191                 let nonce = Nonce::from_entropy_source(entropy_source);
 192                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
 193                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 194                 OfferBuilder {
 195                         offer: OfferContents {
 196                                 chains: None, metadata: Some(metadata), amount: None, description,
 197                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 198                                 supported_quantity: Quantity::One, signing_pubkey: node_id,
 199                         },
 200                         metadata_strategy: core::marker::PhantomData,
 201                         secp_ctx: Some(secp_ctx),
 202                 }
 203         }
 204 }
 205
 206 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 207         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 208         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 209         ///
 210         /// See [`Offer::chains`] on how this relates to the payment currency.
 211         ///
 212         /// Successive calls to this method will add another chain hash.
 213         pub fn chain(self, network: Network) -> Self {
 214                 self.chain_hash(ChainHash::using_genesis_block(network))
 215         }
 216
 217         /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
 218         /// [`Network::Bitcoin`] is assumed to be the only one supported.
 219         ///
 220         /// See [`Offer::chains`] on how this relates to the payment currency.
 221         ///
 222         /// Successive calls to this method will add another chain hash.
 223         pub(crate) fn chain_hash(mut self, chain: ChainHash) -> Self {
 224                 let chains = self.offer.chains.get_or_insert_with(Vec::new);
 225                 if !chains.contains(&chain) {
 226                         chains.push(chain);
 227                 }
 228
 229                 self
 230         }
 231
 232         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 233         ///
 234         /// Successive calls to this method will override the previous setting.
 235         pub fn amount_msats(self, amount_msats: u64) -> Self {
 236                 self.amount(Amount::Bitcoin { amount_msats })
 237         }
 238
 239         /// Sets the [`Offer::amount`].
 240         ///
 241         /// Successive calls to this method will override the previous setting.
 242         pub(super) fn amount(mut self, amount: Amount) -> Self {
 243                 self.offer.amount = Some(amount);
 244                 self
 245         }
 246
 247         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 248         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 249         ///
 250         /// Successive calls to this method will override the previous setting.
 251         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 252                 self.offer.absolute_expiry = Some(absolute_expiry);
 253                 self
 254         }
 255
 256         /// Sets the [`Offer::issuer`].
 257         ///
 258         /// Successive calls to this method will override the previous setting.
 259         pub fn issuer(mut self, issuer: String) -> Self {
 260                 self.offer.issuer = Some(issuer);
 261                 self
 262         }
 263
 264         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 265         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 266         ///
 267         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 268         /// adding duplicate paths.
 269         pub fn path(mut self, path: BlindedPath) -> Self {
 270                 self.offer.paths.get_or_insert_with(Vec::new).push(path);
 271                 self
 272         }
 273
 274         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 275         /// [`Quantity::One`].
 276         ///
 277         /// Successive calls to this method will override the previous setting.
 278         pub fn supported_quantity(mut self, quantity: Quantity) -> Self {
 279                 self.offer.supported_quantity = quantity;
 280                 self
 281         }
 282
 283         /// Builds an [`Offer`] from the builder's settings.
 284         pub fn build(mut self) -> Result<Offer, Bolt12SemanticError> {
 285                 match self.offer.amount {
 286                         Some(Amount::Bitcoin { amount_msats }) => {
 287                                 if amount_msats > MAX_VALUE_MSAT {
 288                                         return Err(Bolt12SemanticError::InvalidAmount);
 289                                 }
 290                         },
 291                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 292                         None => {},
 293                 }
 294
 295                 if let Some(chains) = &self.offer.chains {
 296                         if chains.len() == 1 && chains[0] == self.offer.implied_chain() {
 297                                 self.offer.chains = None;
 298                         }
 299                 }
 300
 301                 Ok(self.build_without_checks())
 302         }
 303
 304         fn build_without_checks(mut self) -> Offer {
 305                 // Create the metadata for stateless verification of an InvoiceRequest.
 306                 if let Some(mut metadata) = self.offer.metadata.take() {
 307                         if metadata.has_derivation_material() {
 308                                 if self.offer.paths.is_none() {
 309                                         metadata = metadata.without_keys();
 310                                 }
 311
 312                                 let mut tlv_stream = self.offer.as_tlv_stream();
 313                                 debug_assert_eq!(tlv_stream.metadata, None);
 314                                 tlv_stream.metadata = None;
 315                                 if metadata.derives_recipient_keys() {
 316                                         tlv_stream.node_id = None;
 317                                 }
 318
 319                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
 320                                 metadata = derived_metadata;
 321                                 if let Some(keys) = keys {
 322                                         self.offer.signing_pubkey = keys.public_key();
 323                                 }
 324                         }
 325
 326                         self.offer.metadata = Some(metadata);
 327                 }
 328
 329                 let mut bytes = Vec::new();
 330                 self.offer.write(&mut bytes).unwrap();
 331
 332                 Offer { bytes, contents: self.offer }
 333         }
 334 }
 335
 336 #[cfg(test)]
 337 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 338         fn features_unchecked(mut self, features: OfferFeatures) -> Self {
 339                 self.offer.features = features;
 340                 self
 341         }
 342
 343         pub(crate) fn clear_paths(mut self) -> Self {
 344                 self.offer.paths = None;
 345                 self
 346         }
 347
 348         pub(super) fn build_unchecked(self) -> Offer {
 349                 self.build_without_checks()
 350         }
 351 }
 352
 353 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 354 ///
 355 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 356 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 357 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 358 ///
 359 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 360 /// latter.
 361 ///
 362 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 363 ///
 364 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 365 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 366 #[derive(Clone, Debug)]
 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 PartialEq for Offer {
 588         fn eq(&self, other: &Self) -> bool {
 589                 self.bytes.eq(&other.bytes)
 590         }
 591 }
 592
 593 impl Eq for Offer {}
 594
 595 impl Hash for Offer {
 596         fn hash<H: Hasher>(&self, state: &mut H) {
 597                 self.bytes.hash(state);
 598         }
 599 }
 600
 601 impl OfferContents {
 602         pub fn chains(&self) -> Vec<ChainHash> {
 603                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 604         }
 605
 606         pub fn implied_chain(&self) -> ChainHash {
 607                 ChainHash::using_genesis_block(Network::Bitcoin)
 608         }
 609
 610         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 611                 self.chains().contains(&chain)
 612         }
 613
 614         pub fn metadata(&self) -> Option<&Vec<u8>> {
 615                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 616         }
 617
 618         pub fn amount(&self) -> Option<&Amount> {
 619                 self.amount.as_ref()
 620         }
 621
 622         pub fn description(&self) -> PrintableString {
 623                 PrintableString(&self.description)
 624         }
 625
 626         pub fn features(&self) -> &OfferFeatures {
 627                 &self.features
 628         }
 629
 630         pub fn absolute_expiry(&self) -> Option<Duration> {
 631                 self.absolute_expiry
 632         }
 633
 634         #[cfg(feature = "std")]
 635         pub(super) fn is_expired(&self) -> bool {
 636                 SystemTime::UNIX_EPOCH
 637                         .elapsed()
 638                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 639                         .unwrap_or(false)
 640         }
 641
 642         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 643                 self.absolute_expiry
 644                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 645                         .unwrap_or(false)
 646         }
 647
 648         pub fn issuer(&self) -> Option<PrintableString> {
 649                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 650         }
 651
 652         pub fn paths(&self) -> &[BlindedPath] {
 653                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 654         }
 655
 656         pub(super) fn check_amount_msats_for_quantity(
 657                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 658         ) -> Result<(), Bolt12SemanticError> {
 659                 let offer_amount_msats = match self.amount {
 660                         None => 0,
 661                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 662                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 663                 };
 664
 665                 if !self.expects_quantity() || quantity.is_some() {
 666                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 667                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 668                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 669
 670                         if amount_msats < expected_amount_msats {
 671                                 return Err(Bolt12SemanticError::InsufficientAmount);
 672                         }
 673
 674                         if amount_msats > MAX_VALUE_MSAT {
 675                                 return Err(Bolt12SemanticError::InvalidAmount);
 676                         }
 677                 }
 678
 679                 Ok(())
 680         }
 681
 682         pub fn supported_quantity(&self) -> Quantity {
 683                 self.supported_quantity
 684         }
 685
 686         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 687                 let expects_quantity = self.expects_quantity();
 688                 match quantity {
 689                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 690                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 691                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 692                                 Err(Bolt12SemanticError::InvalidQuantity)
 693                         },
 694                         _ => Ok(()),
 695                 }
 696         }
 697
 698         fn is_valid_quantity(&self, quantity: u64) -> bool {
 699                 match self.supported_quantity {
 700                         Quantity::Bounded(n) => quantity <= n.get(),
 701                         Quantity::Unbounded => quantity > 0,
 702                         Quantity::One => quantity == 1,
 703                 }
 704         }
 705
 706         fn expects_quantity(&self) -> bool {
 707                 match self.supported_quantity {
 708                         Quantity::Bounded(_) => true,
 709                         Quantity::Unbounded => true,
 710                         Quantity::One => false,
 711                 }
 712         }
 713
 714         pub(super) fn signing_pubkey(&self) -> PublicKey {
 715                 self.signing_pubkey
 716         }
 717
 718         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 719         pub(super) fn verify<T: secp256k1::Signing>(
 720                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 721         ) -> Result<Option<KeyPair>, ()> {
 722                 match self.metadata() {
 723                         Some(metadata) => {
 724                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 725                                         match record.r#type {
 726                                                 OFFER_METADATA_TYPE => false,
 727                                                 OFFER_NODE_ID_TYPE => {
 728                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 729                                                 },
 730                                                 _ => true,
 731                                         }
 732                                 });
 733                                 signer::verify_recipient_metadata(
 734                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
 735                                 )
 736                         },
 737                         None => Err(()),
 738                 }
 739         }
 740
 741         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 742                 let (currency, amount) = match &self.amount {
 743                         None => (None, None),
 744                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 745                         Some(Amount::Currency { iso4217_code, amount }) => (
 746                                 Some(iso4217_code), Some(*amount)
 747                         ),
 748                 };
 749
 750                 let features = {
 751                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 752                 };
 753
 754                 OfferTlvStreamRef {
 755                         chains: self.chains.as_ref(),
 756                         metadata: self.metadata(),
 757                         currency,
 758                         amount,
 759                         description: Some(&self.description),
 760                         features,
 761                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 762                         paths: self.paths.as_ref(),
 763                         issuer: self.issuer.as_ref(),
 764                         quantity_max: self.supported_quantity.to_tlv_record(),
 765                         node_id: Some(&self.signing_pubkey),
 766                 }
 767         }
 768 }
 769
 770 impl Writeable for Offer {
 771         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 772                 WithoutLength(&self.bytes).write(writer)
 773         }
 774 }
 775
 776 impl Writeable for OfferContents {
 777         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 778                 self.as_tlv_stream().write(writer)
 779         }
 780 }
 781
 782 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 783 /// another currency.
 784 #[derive(Clone, Debug, PartialEq)]
 785 pub enum Amount {
 786         /// An amount of bitcoin.
 787         Bitcoin {
 788                 /// The amount in millisatoshi.
 789                 amount_msats: u64,
 790         },
 791         /// An amount of currency specified using ISO 4712.
 792         Currency {
 793                 /// The currency that the amount is denominated in.
 794                 iso4217_code: CurrencyCode,
 795                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 796                 amount: u64,
 797         },
 798 }
 799
 800 /// An ISO 4712 three-letter currency code (e.g., USD).
 801 pub type CurrencyCode = [u8; 3];
 802
 803 /// Quantity of items supported by an [`Offer`].
 804 #[derive(Clone, Copy, Debug, PartialEq)]
 805 pub enum Quantity {
 806         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
 807         /// but is limited (e.g., because of per customer or inventory limits).
 808         ///
 809         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
 810         /// is supported.
 811         Bounded(NonZeroU64),
 812         /// One or more items. Use when more than one item can be requested without any limit.
 813         Unbounded,
 814         /// Only one item. Use when only a single item can be requested.
 815         One,
 816 }
 817
 818 impl Quantity {
 819         fn to_tlv_record(&self) -> Option<u64> {
 820                 match self {
 821                         Quantity::Bounded(n) => Some(n.get()),
 822                         Quantity::Unbounded => Some(0),
 823                         Quantity::One => None,
 824                 }
 825         }
 826 }
 827
 828 /// Valid type range for offer TLV records.
 829 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
 830
 831 /// TLV record type for [`Offer::metadata`].
 832 const OFFER_METADATA_TYPE: u64 = 4;
 833
 834 /// TLV record type for [`Offer::signing_pubkey`].
 835 const OFFER_NODE_ID_TYPE: u64 = 22;
 836
 837 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
 838         (2, chains: (Vec<ChainHash>, WithoutLength)),
 839         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
 840         (6, currency: CurrencyCode),
 841         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 842         (10, description: (String, WithoutLength)),
 843         (12, features: (OfferFeatures, WithoutLength)),
 844         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 845         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 846         (18, issuer: (String, WithoutLength)),
 847         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 848         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
 849 });
 850
 851 impl Bech32Encode for Offer {
 852         const BECH32_HRP: &'static str = "lno";
 853 }
 854
 855 impl FromStr for Offer {
 856         type Err = Bolt12ParseError;
 857
 858         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 859                 Self::from_bech32_str(s)
 860         }
 861 }
 862
 863 impl TryFrom<Vec<u8>> for Offer {
 864         type Error = Bolt12ParseError;
 865
 866         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 867                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
 868                 let ParsedMessage { bytes, tlv_stream } = offer;
 869                 let contents = OfferContents::try_from(tlv_stream)?;
 870                 Ok(Offer { bytes, contents })
 871         }
 872 }
 873
 874 impl TryFrom<OfferTlvStream> for OfferContents {
 875         type Error = Bolt12SemanticError;
 876
 877         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 878                 let OfferTlvStream {
 879                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 880                         issuer, quantity_max, node_id,
 881                 } = tlv_stream;
 882
 883                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
 884
 885                 let amount = match (currency, amount) {
 886                         (None, None) => None,
 887                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
 888                                 return Err(Bolt12SemanticError::InvalidAmount);
 889                         },
 890                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 891                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
 892                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
 893                 };
 894
 895                 let description = match description {
 896                         None => return Err(Bolt12SemanticError::MissingDescription),
 897                         Some(description) => description,
 898                 };
 899
 900                 let features = features.unwrap_or_else(OfferFeatures::empty);
 901
 902                 let absolute_expiry = absolute_expiry
 903                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
 904
 905                 let supported_quantity = match quantity_max {
 906                         None => Quantity::One,
 907                         Some(0) => Quantity::Unbounded,
 908                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
 909                 };
 910
 911                 let signing_pubkey = match node_id {
 912                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 913                         Some(node_id) => node_id,
 914                 };
 915
 916                 Ok(OfferContents {
 917                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
 918                         supported_quantity, signing_pubkey,
 919                 })
 920         }
 921 }
 922
 923 impl core::fmt::Display for Offer {
 924         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 925                 self.fmt_bech32_str(f)
 926         }
 927 }
 928
 929 #[cfg(test)]
 930 mod tests {
 931         use super::{Amount, Offer, OfferBuilder, OfferTlvStreamRef, Quantity};
 932
 933         use bitcoin::blockdata::constants::ChainHash;
 934         use bitcoin::network::constants::Network;
 935         use bitcoin::secp256k1::Secp256k1;
 936         use core::convert::TryFrom;
 937         use core::num::NonZeroU64;
 938         use core::time::Duration;
 939         use crate::blinded_path::{BlindedHop, BlindedPath};
 940         use crate::sign::KeyMaterial;
 941         use crate::ln::features::OfferFeatures;
 942         use crate::ln::inbound_payment::ExpandedKey;
 943         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 944         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 945         use crate::offers::test_utils::*;
 946         use crate::util::ser::{BigSize, Writeable};
 947         use crate::util::string::PrintableString;
 948
 949         #[test]
 950         fn builds_offer_with_defaults() {
 951                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
 952
 953                 let mut buffer = Vec::new();
 954                 offer.write(&mut buffer).unwrap();
 955
 956                 assert_eq!(offer.bytes, buffer.as_slice());
 957                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
 958                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
 959                 assert_eq!(offer.metadata(), None);
 960                 assert_eq!(offer.amount(), None);
 961                 assert_eq!(offer.description(), PrintableString("foo"));
 962                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
 963                 assert_eq!(offer.absolute_expiry(), None);
 964                 #[cfg(feature = "std")]
 965                 assert!(!offer.is_expired());
 966                 assert_eq!(offer.paths(), &[]);
 967                 assert_eq!(offer.issuer(), None);
 968                 assert_eq!(offer.supported_quantity(), Quantity::One);
 969                 assert_eq!(offer.signing_pubkey(), pubkey(42));
 970
 971                 assert_eq!(
 972                         offer.as_tlv_stream(),
 973                         OfferTlvStreamRef {
 974                                 chains: None,
 975                                 metadata: None,
 976                                 currency: None,
 977                                 amount: None,
 978                                 description: Some(&String::from("foo")),
 979                                 features: None,
 980                                 absolute_expiry: None,
 981                                 paths: None,
 982                                 issuer: None,
 983                                 quantity_max: None,
 984                                 node_id: Some(&pubkey(42)),
 985                         },
 986                 );
 987
 988                 if let Err(e) = Offer::try_from(buffer) {
 989                         panic!("error parsing offer: {:?}", e);
 990                 }
 991         }
 992
 993         #[test]
 994         fn builds_offer_with_chains() {
 995                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 996                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 997
 998                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 999                         .chain(Network::Bitcoin)
1000                         .build()
1001                         .unwrap();
1002                 assert!(offer.supports_chain(mainnet));
1003                 assert_eq!(offer.chains(), vec![mainnet]);
1004                 assert_eq!(offer.as_tlv_stream().chains, None);
1005
1006                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1007                         .chain(Network::Testnet)
1008                         .build()
1009                         .unwrap();
1010                 assert!(offer.supports_chain(testnet));
1011                 assert_eq!(offer.chains(), vec![testnet]);
1012                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1013
1014                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1015                         .chain(Network::Testnet)
1016                         .chain(Network::Testnet)
1017                         .build()
1018                         .unwrap();
1019                 assert!(offer.supports_chain(testnet));
1020                 assert_eq!(offer.chains(), vec![testnet]);
1021                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1022
1023                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1024                         .chain(Network::Bitcoin)
1025                         .chain(Network::Testnet)
1026                         .build()
1027                         .unwrap();
1028                 assert!(offer.supports_chain(mainnet));
1029                 assert!(offer.supports_chain(testnet));
1030                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1031                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1032         }
1033
1034         #[test]
1035         fn builds_offer_with_metadata() {
1036                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1037                         .metadata(vec![42; 32]).unwrap()
1038                         .build()
1039                         .unwrap();
1040                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1041                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1042
1043                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1044                         .metadata(vec![42; 32]).unwrap()
1045                         .metadata(vec![43; 32]).unwrap()
1046                         .build()
1047                         .unwrap();
1048                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1049                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1050         }
1051
1052         #[test]
1053         fn builds_offer_with_metadata_derived() {
1054                 let desc = "foo".to_string();
1055                 let node_id = recipient_pubkey();
1056                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1057                 let entropy = FixedEntropy {};
1058                 let secp_ctx = Secp256k1::new();
1059
1060                 let offer = OfferBuilder
1061                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1062                         .amount_msats(1000)
1063                         .build().unwrap();
1064                 assert_eq!(offer.signing_pubkey(), node_id);
1065
1066                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1067                         .build().unwrap()
1068                         .sign(payer_sign).unwrap();
1069                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1070
1071                 // Fails verification with altered offer field
1072                 let mut tlv_stream = offer.as_tlv_stream();
1073                 tlv_stream.amount = Some(100);
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                 // Fails verification with altered metadata
1085                 let mut tlv_stream = offer.as_tlv_stream();
1086                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1087                 tlv_stream.metadata = Some(&metadata);
1088
1089                 let mut encoded_offer = Vec::new();
1090                 tlv_stream.write(&mut encoded_offer).unwrap();
1091
1092                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1093                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1094                         .build().unwrap()
1095                         .sign(payer_sign).unwrap();
1096                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1097         }
1098
1099         #[test]
1100         fn builds_offer_with_derived_signing_pubkey() {
1101                 let desc = "foo".to_string();
1102                 let node_id = recipient_pubkey();
1103                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1104                 let entropy = FixedEntropy {};
1105                 let secp_ctx = Secp256k1::new();
1106
1107                 let blinded_path = BlindedPath {
1108                         introduction_node_id: pubkey(40),
1109                         blinding_point: pubkey(41),
1110                         blinded_hops: vec![
1111                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1112                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1113                         ],
1114                 };
1115
1116                 let offer = OfferBuilder
1117                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1118                         .amount_msats(1000)
1119                         .path(blinded_path)
1120                         .build().unwrap();
1121                 assert_ne!(offer.signing_pubkey(), node_id);
1122
1123                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1124                         .build().unwrap()
1125                         .sign(payer_sign).unwrap();
1126                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1127
1128                 // Fails verification with altered offer field
1129                 let mut tlv_stream = offer.as_tlv_stream();
1130                 tlv_stream.amount = Some(100);
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                 // Fails verification with altered signing pubkey
1142                 let mut tlv_stream = offer.as_tlv_stream();
1143                 let signing_pubkey = pubkey(1);
1144                 tlv_stream.node_id = Some(&signing_pubkey);
1145
1146                 let mut encoded_offer = Vec::new();
1147                 tlv_stream.write(&mut encoded_offer).unwrap();
1148
1149                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1150                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1151                         .build().unwrap()
1152                         .sign(payer_sign).unwrap();
1153                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1154         }
1155
1156         #[test]
1157         fn builds_offer_with_amount() {
1158                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1159                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1160
1161                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1162                         .amount_msats(1000)
1163                         .build()
1164                         .unwrap();
1165                 let tlv_stream = offer.as_tlv_stream();
1166                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1167                 assert_eq!(tlv_stream.amount, Some(1000));
1168                 assert_eq!(tlv_stream.currency, None);
1169
1170                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1171                         .amount(currency_amount.clone());
1172                 let tlv_stream = builder.offer.as_tlv_stream();
1173                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1174                 assert_eq!(tlv_stream.amount, Some(10));
1175                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1176                 match builder.build() {
1177                         Ok(_) => panic!("expected error"),
1178                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1179                 }
1180
1181                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1182                         .amount(currency_amount.clone())
1183                         .amount(bitcoin_amount.clone())
1184                         .build()
1185                         .unwrap();
1186                 let tlv_stream = offer.as_tlv_stream();
1187                 assert_eq!(tlv_stream.amount, Some(1000));
1188                 assert_eq!(tlv_stream.currency, None);
1189
1190                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1191                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1192                         Ok(_) => panic!("expected error"),
1193                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1194                 }
1195         }
1196
1197         #[test]
1198         fn builds_offer_with_features() {
1199                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1200                         .features_unchecked(OfferFeatures::unknown())
1201                         .build()
1202                         .unwrap();
1203                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1204                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1205
1206                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1207                         .features_unchecked(OfferFeatures::unknown())
1208                         .features_unchecked(OfferFeatures::empty())
1209                         .build()
1210                         .unwrap();
1211                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1212                 assert_eq!(offer.as_tlv_stream().features, None);
1213         }
1214
1215         #[test]
1216         fn builds_offer_with_absolute_expiry() {
1217                 let future_expiry = Duration::from_secs(u64::max_value());
1218                 let past_expiry = Duration::from_secs(0);
1219                 let now = future_expiry - Duration::from_secs(1_000);
1220
1221                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1222                         .absolute_expiry(future_expiry)
1223                         .build()
1224                         .unwrap();
1225                 #[cfg(feature = "std")]
1226                 assert!(!offer.is_expired());
1227                 assert!(!offer.is_expired_no_std(now));
1228                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1229                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1230
1231                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1232                         .absolute_expiry(future_expiry)
1233                         .absolute_expiry(past_expiry)
1234                         .build()
1235                         .unwrap();
1236                 #[cfg(feature = "std")]
1237                 assert!(offer.is_expired());
1238                 assert!(offer.is_expired_no_std(now));
1239                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1240                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1241         }
1242
1243         #[test]
1244         fn builds_offer_with_paths() {
1245                 let paths = vec![
1246                         BlindedPath {
1247                                 introduction_node_id: pubkey(40),
1248                                 blinding_point: pubkey(41),
1249                                 blinded_hops: vec![
1250                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1251                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1252                                 ],
1253                         },
1254                         BlindedPath {
1255                                 introduction_node_id: pubkey(40),
1256                                 blinding_point: pubkey(41),
1257                                 blinded_hops: vec![
1258                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1259                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1260                                 ],
1261                         },
1262                 ];
1263
1264                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1265                         .path(paths[0].clone())
1266                         .path(paths[1].clone())
1267                         .build()
1268                         .unwrap();
1269                 let tlv_stream = offer.as_tlv_stream();
1270                 assert_eq!(offer.paths(), paths.as_slice());
1271                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1272                 assert_ne!(pubkey(42), pubkey(44));
1273                 assert_eq!(tlv_stream.paths, Some(&paths));
1274                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1275         }
1276
1277         #[test]
1278         fn builds_offer_with_issuer() {
1279                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1280                         .issuer("bar".into())
1281                         .build()
1282                         .unwrap();
1283                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1284                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1285
1286                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1287                         .issuer("bar".into())
1288                         .issuer("baz".into())
1289                         .build()
1290                         .unwrap();
1291                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1292                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1293         }
1294
1295         #[test]
1296         fn builds_offer_with_supported_quantity() {
1297                 let one = NonZeroU64::new(1).unwrap();
1298                 let ten = NonZeroU64::new(10).unwrap();
1299
1300                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1301                         .supported_quantity(Quantity::One)
1302                         .build()
1303                         .unwrap();
1304                 let tlv_stream = offer.as_tlv_stream();
1305                 assert_eq!(offer.supported_quantity(), Quantity::One);
1306                 assert_eq!(tlv_stream.quantity_max, None);
1307
1308                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1309                         .supported_quantity(Quantity::Unbounded)
1310                         .build()
1311                         .unwrap();
1312                 let tlv_stream = offer.as_tlv_stream();
1313                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1314                 assert_eq!(tlv_stream.quantity_max, Some(0));
1315
1316                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1317                         .supported_quantity(Quantity::Bounded(ten))
1318                         .build()
1319                         .unwrap();
1320                 let tlv_stream = offer.as_tlv_stream();
1321                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1322                 assert_eq!(tlv_stream.quantity_max, Some(10));
1323
1324                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1325                         .supported_quantity(Quantity::Bounded(one))
1326                         .build()
1327                         .unwrap();
1328                 let tlv_stream = offer.as_tlv_stream();
1329                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1330                 assert_eq!(tlv_stream.quantity_max, Some(1));
1331
1332                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1333                         .supported_quantity(Quantity::Bounded(ten))
1334                         .supported_quantity(Quantity::One)
1335                         .build()
1336                         .unwrap();
1337                 let tlv_stream = offer.as_tlv_stream();
1338                 assert_eq!(offer.supported_quantity(), Quantity::One);
1339                 assert_eq!(tlv_stream.quantity_max, None);
1340         }
1341
1342         #[test]
1343         fn fails_requesting_invoice_with_unknown_required_features() {
1344                 match OfferBuilder::new("foo".into(), pubkey(42))
1345                         .features_unchecked(OfferFeatures::unknown())
1346                         .build().unwrap()
1347                         .request_invoice(vec![1; 32], pubkey(43))
1348                 {
1349                         Ok(_) => panic!("expected error"),
1350                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1351                 }
1352         }
1353
1354         #[test]
1355         fn parses_offer_with_chains() {
1356                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1357                         .chain(Network::Bitcoin)
1358                         .chain(Network::Testnet)
1359                         .build()
1360                         .unwrap();
1361                 if let Err(e) = offer.to_string().parse::<Offer>() {
1362                         panic!("error parsing offer: {:?}", e);
1363                 }
1364         }
1365
1366         #[test]
1367         fn parses_offer_with_amount() {
1368                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1369                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1370                         .build()
1371                         .unwrap();
1372                 if let Err(e) = offer.to_string().parse::<Offer>() {
1373                         panic!("error parsing offer: {:?}", e);
1374                 }
1375
1376                 let mut tlv_stream = offer.as_tlv_stream();
1377                 tlv_stream.amount = Some(1000);
1378                 tlv_stream.currency = Some(b"USD");
1379
1380                 let mut encoded_offer = Vec::new();
1381                 tlv_stream.write(&mut encoded_offer).unwrap();
1382
1383                 if let Err(e) = Offer::try_from(encoded_offer) {
1384                         panic!("error parsing offer: {:?}", e);
1385                 }
1386
1387                 let mut tlv_stream = offer.as_tlv_stream();
1388                 tlv_stream.amount = None;
1389                 tlv_stream.currency = Some(b"USD");
1390
1391                 let mut encoded_offer = Vec::new();
1392                 tlv_stream.write(&mut encoded_offer).unwrap();
1393
1394                 match Offer::try_from(encoded_offer) {
1395                         Ok(_) => panic!("expected error"),
1396                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1397                 }
1398
1399                 let mut tlv_stream = offer.as_tlv_stream();
1400                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1401                 tlv_stream.currency = None;
1402
1403                 let mut encoded_offer = Vec::new();
1404                 tlv_stream.write(&mut encoded_offer).unwrap();
1405
1406                 match Offer::try_from(encoded_offer) {
1407                         Ok(_) => panic!("expected error"),
1408                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1409                 }
1410         }
1411
1412         #[test]
1413         fn parses_offer_with_description() {
1414                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1415                 if let Err(e) = offer.to_string().parse::<Offer>() {
1416                         panic!("error parsing offer: {:?}", e);
1417                 }
1418
1419                 let mut tlv_stream = offer.as_tlv_stream();
1420                 tlv_stream.description = None;
1421
1422                 let mut encoded_offer = Vec::new();
1423                 tlv_stream.write(&mut encoded_offer).unwrap();
1424
1425                 match Offer::try_from(encoded_offer) {
1426                         Ok(_) => panic!("expected error"),
1427                         Err(e) => {
1428                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1429                         },
1430                 }
1431         }
1432
1433         #[test]
1434         fn parses_offer_with_paths() {
1435                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1436                         .path(BlindedPath {
1437                                 introduction_node_id: pubkey(40),
1438                                 blinding_point: pubkey(41),
1439                                 blinded_hops: vec![
1440                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1441                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1442                                 ],
1443                         })
1444                         .path(BlindedPath {
1445                                 introduction_node_id: pubkey(40),
1446                                 blinding_point: pubkey(41),
1447                                 blinded_hops: vec![
1448                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1449                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1450                                 ],
1451                         })
1452                         .build()
1453                         .unwrap();
1454                 if let Err(e) = offer.to_string().parse::<Offer>() {
1455                         panic!("error parsing offer: {:?}", e);
1456                 }
1457
1458                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1459                 builder.offer.paths = Some(vec![]);
1460
1461                 let offer = builder.build().unwrap();
1462                 if let Err(e) = offer.to_string().parse::<Offer>() {
1463                         panic!("error parsing offer: {:?}", e);
1464                 }
1465         }
1466
1467         #[test]
1468         fn parses_offer_with_quantity() {
1469                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1470                         .supported_quantity(Quantity::One)
1471                         .build()
1472                         .unwrap();
1473                 if let Err(e) = offer.to_string().parse::<Offer>() {
1474                         panic!("error parsing offer: {:?}", e);
1475                 }
1476
1477                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1478                         .supported_quantity(Quantity::Unbounded)
1479                         .build()
1480                         .unwrap();
1481                 if let Err(e) = offer.to_string().parse::<Offer>() {
1482                         panic!("error parsing offer: {:?}", e);
1483                 }
1484
1485                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1486                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1487                         .build()
1488                         .unwrap();
1489                 if let Err(e) = offer.to_string().parse::<Offer>() {
1490                         panic!("error parsing offer: {:?}", e);
1491                 }
1492
1493                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1494                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1495                         .build()
1496                         .unwrap();
1497                 if let Err(e) = offer.to_string().parse::<Offer>() {
1498                         panic!("error parsing offer: {:?}", e);
1499                 }
1500         }
1501
1502         #[test]
1503         fn parses_offer_with_node_id() {
1504                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1505                 if let Err(e) = offer.to_string().parse::<Offer>() {
1506                         panic!("error parsing offer: {:?}", e);
1507                 }
1508
1509                 let mut tlv_stream = offer.as_tlv_stream();
1510                 tlv_stream.node_id = None;
1511
1512                 let mut encoded_offer = Vec::new();
1513                 tlv_stream.write(&mut encoded_offer).unwrap();
1514
1515                 match Offer::try_from(encoded_offer) {
1516                         Ok(_) => panic!("expected error"),
1517                         Err(e) => {
1518                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1519                         },
1520                 }
1521         }
1522
1523         #[test]
1524         fn fails_parsing_offer_with_extra_tlv_records() {
1525                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1526
1527                 let mut encoded_offer = Vec::new();
1528                 offer.write(&mut encoded_offer).unwrap();
1529                 BigSize(80).write(&mut encoded_offer).unwrap();
1530                 BigSize(32).write(&mut encoded_offer).unwrap();
1531                 [42u8; 32].write(&mut encoded_offer).unwrap();
1532
1533                 match Offer::try_from(encoded_offer) {
1534                         Ok(_) => panic!("expected error"),
1535                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1536                 }
1537         }
1538 }
1539
1540 #[cfg(test)]
1541 mod bolt12_tests {
1542         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1543         use crate::ln::msgs::DecodeError;
1544
1545         #[test]
1546         fn parses_bech32_encoded_offers() {
1547                 let offers = [
1548                         // Minimal bolt12 offer
1549                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1550
1551                         // for testnet
1552                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1553
1554                         // for bitcoin (redundant)
1555                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1556
1557                         // for bitcoin or liquidv1
1558                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1559
1560                         // with metadata
1561                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1562
1563                         // with amount
1564                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1565
1566                         // with currency
1567                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1568
1569                         // with expiry
1570                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1571
1572                         // with issuer
1573                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1574
1575                         // with quantity
1576                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1577
1578                         // with unlimited (or unknown) quantity
1579                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1580
1581                         // with single quantity (weird but valid)
1582                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1583
1584                         // with feature
1585                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1586
1587                         // with blinded path via Bob (0x424242...), blinding 020202...
1588                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1589
1590                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1591                         "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",
1592
1593                         // unknown odd field
1594                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1595                 ];
1596                 for encoded_offer in &offers {
1597                         if let Err(e) = encoded_offer.parse::<Offer>() {
1598                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1599                         }
1600                 }
1601         }
1602
1603         #[test]
1604         fn fails_parsing_bech32_encoded_offers() {
1605                 // Malformed: fields out of order
1606                 assert_eq!(
1607                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1608                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1609                 );
1610
1611                 // Malformed: unknown even TLV type 78
1612                 assert_eq!(
1613                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1614                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1615                 );
1616
1617                 // Malformed: empty
1618                 assert_eq!(
1619                         "lno1".parse::<Offer>(),
1620                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1621                 );
1622
1623                 // Malformed: truncated at type
1624                 assert_eq!(
1625                         "lno1pg".parse::<Offer>(),
1626                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1627                 );
1628
1629                 // Malformed: truncated in length
1630                 assert_eq!(
1631                         "lno1pt7s".parse::<Offer>(),
1632                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1633                 );
1634
1635                 // Malformed: truncated after length
1636                 assert_eq!(
1637                         "lno1pgpq".parse::<Offer>(),
1638                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1639                 );
1640
1641                 // Malformed: truncated in description
1642                 assert_eq!(
1643                         "lno1pgpyz".parse::<Offer>(),
1644                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1645                 );
1646
1647                 // Malformed: invalid offer_chains length
1648                 assert_eq!(
1649                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1650                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1651                 );
1652
1653                 // Malformed: truncated currency UTF-8
1654                 assert_eq!(
1655                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1656                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1657                 );
1658
1659                 // Malformed: invalid currency UTF-8
1660                 assert_eq!(
1661                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1662                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1663                 );
1664
1665                 // Malformed: truncated description UTF-8
1666                 assert_eq!(
1667                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1668                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1669                 );
1670
1671                 // Malformed: invalid description UTF-8
1672                 assert_eq!(
1673                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1674                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1675                 );
1676
1677                 // Malformed: truncated offer_paths
1678                 assert_eq!(
1679                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1680                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1681                 );
1682
1683                 // Malformed: zero num_hops in blinded_path
1684                 assert_eq!(
1685                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1686                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1687                 );
1688
1689                 // Malformed: truncated onionmsg_hop in blinded_path
1690                 assert_eq!(
1691                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1692                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1693                 );
1694
1695                 // Malformed: bad first_node_id in blinded_path
1696                 assert_eq!(
1697                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1698                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1699                 );
1700
1701                 // Malformed: bad blinding in blinded_path
1702                 assert_eq!(
1703                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1704                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1705                 );
1706
1707                 // Malformed: bad blinded_node_id in onionmsg_hop
1708                 assert_eq!(
1709                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1710                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1711                 );
1712
1713                 // Malformed: truncated issuer UTF-8
1714                 assert_eq!(
1715                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1716                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1717                 );
1718
1719                 // Malformed: invalid issuer UTF-8
1720                 assert_eq!(
1721                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1722                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1723                 );
1724
1725                 // Malformed: invalid offer_node_id
1726                 assert_eq!(
1727                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
1728                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1729                 );
1730
1731                 // Contains type >= 80
1732                 assert_eq!(
1733                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1734                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1735                 );
1736
1737                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
1738                 // Contains unknown feature 22
1739                 assert!(
1740                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
1741                 );
1742
1743                 // Missing offer_description
1744                 assert_eq!(
1745                         "lno1zcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese".parse::<Offer>(),
1746                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1747                 );
1748
1749                 // Missing offer_node_id"
1750                 assert_eq!(
1751                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
1752                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1753                 );
1754         }
1755 }