_ 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 pub struct Offer {
 367         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 368         // fields.
 369         pub(super) bytes: Vec<u8>,
 370         pub(super) contents: OfferContents,
 371 }
 372
 373 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 374 /// [`Bolt12Invoice`].
 375 ///
 376 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 377 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 378 #[derive(Clone, Debug)]
 379 #[cfg_attr(test, derive(PartialEq))]
 380 pub(super) struct OfferContents {
 381         chains: Option<Vec<ChainHash>>,
 382         metadata: Option<Metadata>,
 383         amount: Option<Amount>,
 384         description: String,
 385         features: OfferFeatures,
 386         absolute_expiry: Option<Duration>,
 387         issuer: Option<String>,
 388         paths: Option<Vec<BlindedPath>>,
 389         supported_quantity: Quantity,
 390         signing_pubkey: PublicKey,
 391 }
 392
 393 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 394         // TODO: Return a slice once ChainHash has constants.
 395         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 396         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 397         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 398         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 399         /// for the selected chain.
 400         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 401                 $contents.chains()
 402         }
 403
 404         // TODO: Link to corresponding method in `InvoiceRequest`.
 405         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 406         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 407         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 408                 $contents.metadata()
 409         }
 410
 411         /// The minimum amount required for a successful payment of a single item.
 412         pub fn amount(&$self) -> Option<&$crate::offers::offer::Amount> {
 413                 $contents.amount()
 414         }
 415
 416         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 417         /// but with the caveat that it has not been verified in any way.
 418         pub fn description(&$self) -> $crate::util::string::PrintableString {
 419                 $contents.description()
 420         }
 421
 422         /// Features pertaining to the offer.
 423         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 424                 &$contents.features()
 425         }
 426
 427         /// Duration since the Unix epoch when an invoice should no longer be requested.
 428         ///
 429         /// If `None`, the offer does not expire.
 430         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 431                 $contents.absolute_expiry()
 432         }
 433
 434         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 435         /// displayed to the user but with the caveat that it has not been verified in any way.
 436         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 437                 $contents.issuer()
 438         }
 439
 440         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 441         /// recipient privacy by obfuscating its node id.
 442         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 443                 $contents.paths()
 444         }
 445
 446         /// The quantity of items supported.
 447         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 448                 $contents.supported_quantity()
 449         }
 450
 451         /// The public key used by the recipient to sign invoices.
 452         pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
 453                 $contents.signing_pubkey()
 454         }
 455 } }
 456
 457 impl Offer {
 458         offer_accessors!(self, self.contents);
 459
 460         pub(super) fn implied_chain(&self) -> ChainHash {
 461                 self.contents.implied_chain()
 462         }
 463
 464         /// Returns whether the given chain is supported by the offer.
 465         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 466                 self.contents.supports_chain(chain)
 467         }
 468
 469         /// Whether the offer has expired.
 470         #[cfg(feature = "std")]
 471         pub fn is_expired(&self) -> bool {
 472                 self.contents.is_expired()
 473         }
 474
 475         /// Whether the offer has expired given the duration since the Unix epoch.
 476         pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 477                 self.contents.is_expired_no_std(duration_since_epoch)
 478         }
 479
 480         /// Returns whether the given quantity is valid for the offer.
 481         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 482                 self.contents.is_valid_quantity(quantity)
 483         }
 484
 485         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 486         ///
 487         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 488         pub fn expects_quantity(&self) -> bool {
 489                 self.contents.expects_quantity()
 490         }
 491
 492         /// Similar to [`Offer::request_invoice`] except it:
 493         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 494         ///   request,
 495         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 496         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 497         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 498         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 499         ///   be used when sending the payment for the requested invoice.
 500         ///
 501         /// Useful to protect the sender's privacy.
 502         ///
 503         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 504         ///
 505         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 506         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 507         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 508         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 509         pub fn request_invoice_deriving_payer_id<'a, 'b, ES: Deref, T: secp256k1::Signing>(
 510                 &'a self, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>,
 511                 payment_id: PaymentId
 512         ) -> Result<InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>, Bolt12SemanticError>
 513         where
 514                 ES::Target: EntropySource,
 515         {
 516                 if self.offer_features().requires_unknown_bits() {
 517                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 518                 }
 519
 520                 Ok(InvoiceRequestBuilder::deriving_payer_id(
 521                         self, expanded_key, entropy_source, secp_ctx, payment_id
 522                 ))
 523         }
 524
 525         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 526         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 527         ///
 528         /// Useful for recurring payments using the same `payer_id` with different invoices.
 529         ///
 530         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 531         ///
 532         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 533         pub fn request_invoice_deriving_metadata<ES: Deref>(
 534                 &self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 535                 payment_id: PaymentId
 536         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError>
 537         where
 538                 ES::Target: EntropySource,
 539         {
 540                 if self.offer_features().requires_unknown_bits() {
 541                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 542                 }
 543
 544                 Ok(InvoiceRequestBuilder::deriving_metadata(
 545                         self, payer_id, expanded_key, entropy_source, payment_id
 546                 ))
 547         }
 548
 549         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 550         /// which will be reflected in the `Bolt12Invoice` response.
 551         ///
 552         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 553         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 554         /// hashing in the signature calculation.
 555         ///
 556         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 557         /// Otherwise, payments may be correlated.
 558         ///
 559         /// Errors if the offer contains unknown required features.
 560         ///
 561         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 562         ///
 563         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 564         pub fn request_invoice(
 565                 &self, metadata: Vec<u8>, payer_id: PublicKey
 566         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError> {
 567                 if self.offer_features().requires_unknown_bits() {
 568                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 569                 }
 570
 571                 Ok(InvoiceRequestBuilder::new(self, metadata, payer_id))
 572         }
 573
 574         #[cfg(test)]
 575         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 576                 self.contents.as_tlv_stream()
 577         }
 578 }
 579
 580 impl AsRef<[u8]> for Offer {
 581         fn as_ref(&self) -> &[u8] {
 582                 &self.bytes
 583         }
 584 }
 585
 586 impl PartialEq for Offer {
 587         fn eq(&self, other: &Self) -> bool {
 588                 self.bytes.eq(&other.bytes)
 589         }
 590 }
 591
 592 impl Eq for Offer {}
 593
 594 impl OfferContents {
 595         pub fn chains(&self) -> Vec<ChainHash> {
 596                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 597         }
 598
 599         pub fn implied_chain(&self) -> ChainHash {
 600                 ChainHash::using_genesis_block(Network::Bitcoin)
 601         }
 602
 603         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 604                 self.chains().contains(&chain)
 605         }
 606
 607         pub fn metadata(&self) -> Option<&Vec<u8>> {
 608                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 609         }
 610
 611         pub fn amount(&self) -> Option<&Amount> {
 612                 self.amount.as_ref()
 613         }
 614
 615         pub fn description(&self) -> PrintableString {
 616                 PrintableString(&self.description)
 617         }
 618
 619         pub fn features(&self) -> &OfferFeatures {
 620                 &self.features
 621         }
 622
 623         pub fn absolute_expiry(&self) -> Option<Duration> {
 624                 self.absolute_expiry
 625         }
 626
 627         #[cfg(feature = "std")]
 628         pub(super) fn is_expired(&self) -> bool {
 629                 SystemTime::UNIX_EPOCH
 630                         .elapsed()
 631                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 632                         .unwrap_or(false)
 633         }
 634
 635         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 636                 self.absolute_expiry
 637                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 638                         .unwrap_or(false)
 639         }
 640
 641         pub fn issuer(&self) -> Option<PrintableString> {
 642                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 643         }
 644
 645         pub fn paths(&self) -> &[BlindedPath] {
 646                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 647         }
 648
 649         pub(super) fn check_amount_msats_for_quantity(
 650                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 651         ) -> Result<(), Bolt12SemanticError> {
 652                 let offer_amount_msats = match self.amount {
 653                         None => 0,
 654                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 655                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 656                 };
 657
 658                 if !self.expects_quantity() || quantity.is_some() {
 659                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 660                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 661                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 662
 663                         if amount_msats < expected_amount_msats {
 664                                 return Err(Bolt12SemanticError::InsufficientAmount);
 665                         }
 666
 667                         if amount_msats > MAX_VALUE_MSAT {
 668                                 return Err(Bolt12SemanticError::InvalidAmount);
 669                         }
 670                 }
 671
 672                 Ok(())
 673         }
 674
 675         pub fn supported_quantity(&self) -> Quantity {
 676                 self.supported_quantity
 677         }
 678
 679         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 680                 let expects_quantity = self.expects_quantity();
 681                 match quantity {
 682                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 683                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 684                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 685                                 Err(Bolt12SemanticError::InvalidQuantity)
 686                         },
 687                         _ => Ok(()),
 688                 }
 689         }
 690
 691         fn is_valid_quantity(&self, quantity: u64) -> bool {
 692                 match self.supported_quantity {
 693                         Quantity::Bounded(n) => quantity <= n.get(),
 694                         Quantity::Unbounded => quantity > 0,
 695                         Quantity::One => quantity == 1,
 696                 }
 697         }
 698
 699         fn expects_quantity(&self) -> bool {
 700                 match self.supported_quantity {
 701                         Quantity::Bounded(_) => true,
 702                         Quantity::Unbounded => true,
 703                         Quantity::One => false,
 704                 }
 705         }
 706
 707         pub(super) fn signing_pubkey(&self) -> PublicKey {
 708                 self.signing_pubkey
 709         }
 710
 711         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 712         pub(super) fn verify<T: secp256k1::Signing>(
 713                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 714         ) -> Result<Option<KeyPair>, ()> {
 715                 match self.metadata() {
 716                         Some(metadata) => {
 717                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 718                                         match record.r#type {
 719                                                 OFFER_METADATA_TYPE => false,
 720                                                 OFFER_NODE_ID_TYPE => {
 721                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 722                                                 },
 723                                                 _ => true,
 724                                         }
 725                                 });
 726                                 signer::verify_recipient_metadata(
 727                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
 728                                 )
 729                         },
 730                         None => Err(()),
 731                 }
 732         }
 733
 734         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 735                 let (currency, amount) = match &self.amount {
 736                         None => (None, None),
 737                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 738                         Some(Amount::Currency { iso4217_code, amount }) => (
 739                                 Some(iso4217_code), Some(*amount)
 740                         ),
 741                 };
 742
 743                 let features = {
 744                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 745                 };
 746
 747                 OfferTlvStreamRef {
 748                         chains: self.chains.as_ref(),
 749                         metadata: self.metadata(),
 750                         currency,
 751                         amount,
 752                         description: Some(&self.description),
 753                         features,
 754                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 755                         paths: self.paths.as_ref(),
 756                         issuer: self.issuer.as_ref(),
 757                         quantity_max: self.supported_quantity.to_tlv_record(),
 758                         node_id: Some(&self.signing_pubkey),
 759                 }
 760         }
 761 }
 762
 763 impl Writeable for Offer {
 764         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 765                 WithoutLength(&self.bytes).write(writer)
 766         }
 767 }
 768
 769 impl Writeable for OfferContents {
 770         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 771                 self.as_tlv_stream().write(writer)
 772         }
 773 }
 774
 775 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 776 /// another currency.
 777 #[derive(Clone, Debug, PartialEq)]
 778 pub enum Amount {
 779         /// An amount of bitcoin.
 780         Bitcoin {
 781                 /// The amount in millisatoshi.
 782                 amount_msats: u64,
 783         },
 784         /// An amount of currency specified using ISO 4712.
 785         Currency {
 786                 /// The currency that the amount is denominated in.
 787                 iso4217_code: CurrencyCode,
 788                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 789                 amount: u64,
 790         },
 791 }
 792
 793 /// An ISO 4712 three-letter currency code (e.g., USD).
 794 pub type CurrencyCode = [u8; 3];
 795
 796 /// Quantity of items supported by an [`Offer`].
 797 #[derive(Clone, Copy, Debug, PartialEq)]
 798 pub enum Quantity {
 799         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
 800         /// but is limited (e.g., because of per customer or inventory limits).
 801         ///
 802         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
 803         /// is supported.
 804         Bounded(NonZeroU64),
 805         /// One or more items. Use when more than one item can be requested without any limit.
 806         Unbounded,
 807         /// Only one item. Use when only a single item can be requested.
 808         One,
 809 }
 810
 811 impl Quantity {
 812         fn to_tlv_record(&self) -> Option<u64> {
 813                 match self {
 814                         Quantity::Bounded(n) => Some(n.get()),
 815                         Quantity::Unbounded => Some(0),
 816                         Quantity::One => None,
 817                 }
 818         }
 819 }
 820
 821 /// Valid type range for offer TLV records.
 822 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
 823
 824 /// TLV record type for [`Offer::metadata`].
 825 const OFFER_METADATA_TYPE: u64 = 4;
 826
 827 /// TLV record type for [`Offer::signing_pubkey`].
 828 const OFFER_NODE_ID_TYPE: u64 = 22;
 829
 830 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
 831         (2, chains: (Vec<ChainHash>, WithoutLength)),
 832         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
 833         (6, currency: CurrencyCode),
 834         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 835         (10, description: (String, WithoutLength)),
 836         (12, features: (OfferFeatures, WithoutLength)),
 837         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 838         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 839         (18, issuer: (String, WithoutLength)),
 840         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 841         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
 842 });
 843
 844 impl Bech32Encode for Offer {
 845         const BECH32_HRP: &'static str = "lno";
 846 }
 847
 848 impl FromStr for Offer {
 849         type Err = Bolt12ParseError;
 850
 851         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 852                 Self::from_bech32_str(s)
 853         }
 854 }
 855
 856 impl TryFrom<Vec<u8>> for Offer {
 857         type Error = Bolt12ParseError;
 858
 859         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 860                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
 861                 let ParsedMessage { bytes, tlv_stream } = offer;
 862                 let contents = OfferContents::try_from(tlv_stream)?;
 863                 Ok(Offer { bytes, contents })
 864         }
 865 }
 866
 867 impl TryFrom<OfferTlvStream> for OfferContents {
 868         type Error = Bolt12SemanticError;
 869
 870         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 871                 let OfferTlvStream {
 872                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 873                         issuer, quantity_max, node_id,
 874                 } = tlv_stream;
 875
 876                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
 877
 878                 let amount = match (currency, amount) {
 879                         (None, None) => None,
 880                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
 881                                 return Err(Bolt12SemanticError::InvalidAmount);
 882                         },
 883                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 884                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
 885                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
 886                 };
 887
 888                 let description = match description {
 889                         None => return Err(Bolt12SemanticError::MissingDescription),
 890                         Some(description) => description,
 891                 };
 892
 893                 let features = features.unwrap_or_else(OfferFeatures::empty);
 894
 895                 let absolute_expiry = absolute_expiry
 896                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
 897
 898                 let supported_quantity = match quantity_max {
 899                         None => Quantity::One,
 900                         Some(0) => Quantity::Unbounded,
 901                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
 902                 };
 903
 904                 let signing_pubkey = match node_id {
 905                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 906                         Some(node_id) => node_id,
 907                 };
 908
 909                 Ok(OfferContents {
 910                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
 911                         supported_quantity, signing_pubkey,
 912                 })
 913         }
 914 }
 915
 916 impl core::fmt::Display for Offer {
 917         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 918                 self.fmt_bech32_str(f)
 919         }
 920 }
 921
 922 #[cfg(test)]
 923 mod tests {
 924         use super::{Amount, Offer, OfferBuilder, OfferTlvStreamRef, Quantity};
 925
 926         use bitcoin::blockdata::constants::ChainHash;
 927         use bitcoin::network::constants::Network;
 928         use bitcoin::secp256k1::Secp256k1;
 929         use core::convert::TryFrom;
 930         use core::num::NonZeroU64;
 931         use core::time::Duration;
 932         use crate::blinded_path::{BlindedHop, BlindedPath};
 933         use crate::sign::KeyMaterial;
 934         use crate::ln::features::OfferFeatures;
 935         use crate::ln::inbound_payment::ExpandedKey;
 936         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 937         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 938         use crate::offers::test_utils::*;
 939         use crate::util::ser::{BigSize, Writeable};
 940         use crate::util::string::PrintableString;
 941
 942         #[test]
 943         fn builds_offer_with_defaults() {
 944                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
 945
 946                 let mut buffer = Vec::new();
 947                 offer.write(&mut buffer).unwrap();
 948
 949                 assert_eq!(offer.bytes, buffer.as_slice());
 950                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
 951                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
 952                 assert_eq!(offer.metadata(), None);
 953                 assert_eq!(offer.amount(), None);
 954                 assert_eq!(offer.description(), PrintableString("foo"));
 955                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
 956                 assert_eq!(offer.absolute_expiry(), None);
 957                 #[cfg(feature = "std")]
 958                 assert!(!offer.is_expired());
 959                 assert_eq!(offer.paths(), &[]);
 960                 assert_eq!(offer.issuer(), None);
 961                 assert_eq!(offer.supported_quantity(), Quantity::One);
 962                 assert_eq!(offer.signing_pubkey(), pubkey(42));
 963
 964                 assert_eq!(
 965                         offer.as_tlv_stream(),
 966                         OfferTlvStreamRef {
 967                                 chains: None,
 968                                 metadata: None,
 969                                 currency: None,
 970                                 amount: None,
 971                                 description: Some(&String::from("foo")),
 972                                 features: None,
 973                                 absolute_expiry: None,
 974                                 paths: None,
 975                                 issuer: None,
 976                                 quantity_max: None,
 977                                 node_id: Some(&pubkey(42)),
 978                         },
 979                 );
 980
 981                 if let Err(e) = Offer::try_from(buffer) {
 982                         panic!("error parsing offer: {:?}", e);
 983                 }
 984         }
 985
 986         #[test]
 987         fn builds_offer_with_chains() {
 988                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 989                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 990
 991                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 992                         .chain(Network::Bitcoin)
 993                         .build()
 994                         .unwrap();
 995                 assert!(offer.supports_chain(mainnet));
 996                 assert_eq!(offer.chains(), vec![mainnet]);
 997                 assert_eq!(offer.as_tlv_stream().chains, None);
 998
 999                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1000                         .chain(Network::Testnet)
1001                         .build()
1002                         .unwrap();
1003                 assert!(offer.supports_chain(testnet));
1004                 assert_eq!(offer.chains(), vec![testnet]);
1005                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1006
1007                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1008                         .chain(Network::Testnet)
1009                         .chain(Network::Testnet)
1010                         .build()
1011                         .unwrap();
1012                 assert!(offer.supports_chain(testnet));
1013                 assert_eq!(offer.chains(), vec![testnet]);
1014                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1015
1016                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1017                         .chain(Network::Bitcoin)
1018                         .chain(Network::Testnet)
1019                         .build()
1020                         .unwrap();
1021                 assert!(offer.supports_chain(mainnet));
1022                 assert!(offer.supports_chain(testnet));
1023                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1024                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1025         }
1026
1027         #[test]
1028         fn builds_offer_with_metadata() {
1029                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1030                         .metadata(vec![42; 32]).unwrap()
1031                         .build()
1032                         .unwrap();
1033                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1034                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1035
1036                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1037                         .metadata(vec![42; 32]).unwrap()
1038                         .metadata(vec![43; 32]).unwrap()
1039                         .build()
1040                         .unwrap();
1041                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1042                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1043         }
1044
1045         #[test]
1046         fn builds_offer_with_metadata_derived() {
1047                 let desc = "foo".to_string();
1048                 let node_id = recipient_pubkey();
1049                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1050                 let entropy = FixedEntropy {};
1051                 let secp_ctx = Secp256k1::new();
1052
1053                 let offer = OfferBuilder
1054                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1055                         .amount_msats(1000)
1056                         .build().unwrap();
1057                 assert_eq!(offer.signing_pubkey(), node_id);
1058
1059                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1060                         .build().unwrap()
1061                         .sign(payer_sign).unwrap();
1062                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1063
1064                 // Fails verification with altered offer field
1065                 let mut tlv_stream = offer.as_tlv_stream();
1066                 tlv_stream.amount = Some(100);
1067
1068                 let mut encoded_offer = Vec::new();
1069                 tlv_stream.write(&mut encoded_offer).unwrap();
1070
1071                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1072                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1073                         .build().unwrap()
1074                         .sign(payer_sign).unwrap();
1075                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1076
1077                 // Fails verification with altered metadata
1078                 let mut tlv_stream = offer.as_tlv_stream();
1079                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1080                 tlv_stream.metadata = Some(&metadata);
1081
1082                 let mut encoded_offer = Vec::new();
1083                 tlv_stream.write(&mut encoded_offer).unwrap();
1084
1085                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1086                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1087                         .build().unwrap()
1088                         .sign(payer_sign).unwrap();
1089                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1090         }
1091
1092         #[test]
1093         fn builds_offer_with_derived_signing_pubkey() {
1094                 let desc = "foo".to_string();
1095                 let node_id = recipient_pubkey();
1096                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1097                 let entropy = FixedEntropy {};
1098                 let secp_ctx = Secp256k1::new();
1099
1100                 let blinded_path = BlindedPath {
1101                         introduction_node_id: pubkey(40),
1102                         blinding_point: pubkey(41),
1103                         blinded_hops: vec![
1104                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1105                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1106                         ],
1107                 };
1108
1109                 let offer = OfferBuilder
1110                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1111                         .amount_msats(1000)
1112                         .path(blinded_path)
1113                         .build().unwrap();
1114                 assert_ne!(offer.signing_pubkey(), node_id);
1115
1116                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1117                         .build().unwrap()
1118                         .sign(payer_sign).unwrap();
1119                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1120
1121                 // Fails verification with altered offer field
1122                 let mut tlv_stream = offer.as_tlv_stream();
1123                 tlv_stream.amount = Some(100);
1124
1125                 let mut encoded_offer = Vec::new();
1126                 tlv_stream.write(&mut encoded_offer).unwrap();
1127
1128                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1129                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1130                         .build().unwrap()
1131                         .sign(payer_sign).unwrap();
1132                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1133
1134                 // Fails verification with altered signing pubkey
1135                 let mut tlv_stream = offer.as_tlv_stream();
1136                 let signing_pubkey = pubkey(1);
1137                 tlv_stream.node_id = Some(&signing_pubkey);
1138
1139                 let mut encoded_offer = Vec::new();
1140                 tlv_stream.write(&mut encoded_offer).unwrap();
1141
1142                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1143                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1144                         .build().unwrap()
1145                         .sign(payer_sign).unwrap();
1146                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1147         }
1148
1149         #[test]
1150         fn builds_offer_with_amount() {
1151                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1152                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1153
1154                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1155                         .amount_msats(1000)
1156                         .build()
1157                         .unwrap();
1158                 let tlv_stream = offer.as_tlv_stream();
1159                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1160                 assert_eq!(tlv_stream.amount, Some(1000));
1161                 assert_eq!(tlv_stream.currency, None);
1162
1163                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1164                         .amount(currency_amount.clone());
1165                 let tlv_stream = builder.offer.as_tlv_stream();
1166                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1167                 assert_eq!(tlv_stream.amount, Some(10));
1168                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1169                 match builder.build() {
1170                         Ok(_) => panic!("expected error"),
1171                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1172                 }
1173
1174                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1175                         .amount(currency_amount.clone())
1176                         .amount(bitcoin_amount.clone())
1177                         .build()
1178                         .unwrap();
1179                 let tlv_stream = offer.as_tlv_stream();
1180                 assert_eq!(tlv_stream.amount, Some(1000));
1181                 assert_eq!(tlv_stream.currency, None);
1182
1183                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1184                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1185                         Ok(_) => panic!("expected error"),
1186                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1187                 }
1188         }
1189
1190         #[test]
1191         fn builds_offer_with_features() {
1192                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1193                         .features_unchecked(OfferFeatures::unknown())
1194                         .build()
1195                         .unwrap();
1196                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1197                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1198
1199                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1200                         .features_unchecked(OfferFeatures::unknown())
1201                         .features_unchecked(OfferFeatures::empty())
1202                         .build()
1203                         .unwrap();
1204                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1205                 assert_eq!(offer.as_tlv_stream().features, None);
1206         }
1207
1208         #[test]
1209         fn builds_offer_with_absolute_expiry() {
1210                 let future_expiry = Duration::from_secs(u64::max_value());
1211                 let past_expiry = Duration::from_secs(0);
1212                 let now = future_expiry - Duration::from_secs(1_000);
1213
1214                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1215                         .absolute_expiry(future_expiry)
1216                         .build()
1217                         .unwrap();
1218                 #[cfg(feature = "std")]
1219                 assert!(!offer.is_expired());
1220                 assert!(!offer.is_expired_no_std(now));
1221                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1222                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1223
1224                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1225                         .absolute_expiry(future_expiry)
1226                         .absolute_expiry(past_expiry)
1227                         .build()
1228                         .unwrap();
1229                 #[cfg(feature = "std")]
1230                 assert!(offer.is_expired());
1231                 assert!(offer.is_expired_no_std(now));
1232                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1233                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1234         }
1235
1236         #[test]
1237         fn builds_offer_with_paths() {
1238                 let paths = vec![
1239                         BlindedPath {
1240                                 introduction_node_id: pubkey(40),
1241                                 blinding_point: pubkey(41),
1242                                 blinded_hops: vec![
1243                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1244                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1245                                 ],
1246                         },
1247                         BlindedPath {
1248                                 introduction_node_id: pubkey(40),
1249                                 blinding_point: pubkey(41),
1250                                 blinded_hops: vec![
1251                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1252                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1253                                 ],
1254                         },
1255                 ];
1256
1257                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1258                         .path(paths[0].clone())
1259                         .path(paths[1].clone())
1260                         .build()
1261                         .unwrap();
1262                 let tlv_stream = offer.as_tlv_stream();
1263                 assert_eq!(offer.paths(), paths.as_slice());
1264                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1265                 assert_ne!(pubkey(42), pubkey(44));
1266                 assert_eq!(tlv_stream.paths, Some(&paths));
1267                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1268         }
1269
1270         #[test]
1271         fn builds_offer_with_issuer() {
1272                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1273                         .issuer("bar".into())
1274                         .build()
1275                         .unwrap();
1276                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1277                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1278
1279                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1280                         .issuer("bar".into())
1281                         .issuer("baz".into())
1282                         .build()
1283                         .unwrap();
1284                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1285                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1286         }
1287
1288         #[test]
1289         fn builds_offer_with_supported_quantity() {
1290                 let one = NonZeroU64::new(1).unwrap();
1291                 let ten = NonZeroU64::new(10).unwrap();
1292
1293                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1294                         .supported_quantity(Quantity::One)
1295                         .build()
1296                         .unwrap();
1297                 let tlv_stream = offer.as_tlv_stream();
1298                 assert_eq!(offer.supported_quantity(), Quantity::One);
1299                 assert_eq!(tlv_stream.quantity_max, None);
1300
1301                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1302                         .supported_quantity(Quantity::Unbounded)
1303                         .build()
1304                         .unwrap();
1305                 let tlv_stream = offer.as_tlv_stream();
1306                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1307                 assert_eq!(tlv_stream.quantity_max, Some(0));
1308
1309                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1310                         .supported_quantity(Quantity::Bounded(ten))
1311                         .build()
1312                         .unwrap();
1313                 let tlv_stream = offer.as_tlv_stream();
1314                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1315                 assert_eq!(tlv_stream.quantity_max, Some(10));
1316
1317                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1318                         .supported_quantity(Quantity::Bounded(one))
1319                         .build()
1320                         .unwrap();
1321                 let tlv_stream = offer.as_tlv_stream();
1322                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1323                 assert_eq!(tlv_stream.quantity_max, Some(1));
1324
1325                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1326                         .supported_quantity(Quantity::Bounded(ten))
1327                         .supported_quantity(Quantity::One)
1328                         .build()
1329                         .unwrap();
1330                 let tlv_stream = offer.as_tlv_stream();
1331                 assert_eq!(offer.supported_quantity(), Quantity::One);
1332                 assert_eq!(tlv_stream.quantity_max, None);
1333         }
1334
1335         #[test]
1336         fn fails_requesting_invoice_with_unknown_required_features() {
1337                 match OfferBuilder::new("foo".into(), pubkey(42))
1338                         .features_unchecked(OfferFeatures::unknown())
1339                         .build().unwrap()
1340                         .request_invoice(vec![1; 32], pubkey(43))
1341                 {
1342                         Ok(_) => panic!("expected error"),
1343                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1344                 }
1345         }
1346
1347         #[test]
1348         fn parses_offer_with_chains() {
1349                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1350                         .chain(Network::Bitcoin)
1351                         .chain(Network::Testnet)
1352                         .build()
1353                         .unwrap();
1354                 if let Err(e) = offer.to_string().parse::<Offer>() {
1355                         panic!("error parsing offer: {:?}", e);
1356                 }
1357         }
1358
1359         #[test]
1360         fn parses_offer_with_amount() {
1361                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1362                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1363                         .build()
1364                         .unwrap();
1365                 if let Err(e) = offer.to_string().parse::<Offer>() {
1366                         panic!("error parsing offer: {:?}", e);
1367                 }
1368
1369                 let mut tlv_stream = offer.as_tlv_stream();
1370                 tlv_stream.amount = Some(1000);
1371                 tlv_stream.currency = Some(b"USD");
1372
1373                 let mut encoded_offer = Vec::new();
1374                 tlv_stream.write(&mut encoded_offer).unwrap();
1375
1376                 if let Err(e) = Offer::try_from(encoded_offer) {
1377                         panic!("error parsing offer: {:?}", e);
1378                 }
1379
1380                 let mut tlv_stream = offer.as_tlv_stream();
1381                 tlv_stream.amount = None;
1382                 tlv_stream.currency = Some(b"USD");
1383
1384                 let mut encoded_offer = Vec::new();
1385                 tlv_stream.write(&mut encoded_offer).unwrap();
1386
1387                 match Offer::try_from(encoded_offer) {
1388                         Ok(_) => panic!("expected error"),
1389                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1390                 }
1391
1392                 let mut tlv_stream = offer.as_tlv_stream();
1393                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1394                 tlv_stream.currency = None;
1395
1396                 let mut encoded_offer = Vec::new();
1397                 tlv_stream.write(&mut encoded_offer).unwrap();
1398
1399                 match Offer::try_from(encoded_offer) {
1400                         Ok(_) => panic!("expected error"),
1401                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1402                 }
1403         }
1404
1405         #[test]
1406         fn parses_offer_with_description() {
1407                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1408                 if let Err(e) = offer.to_string().parse::<Offer>() {
1409                         panic!("error parsing offer: {:?}", e);
1410                 }
1411
1412                 let mut tlv_stream = offer.as_tlv_stream();
1413                 tlv_stream.description = None;
1414
1415                 let mut encoded_offer = Vec::new();
1416                 tlv_stream.write(&mut encoded_offer).unwrap();
1417
1418                 match Offer::try_from(encoded_offer) {
1419                         Ok(_) => panic!("expected error"),
1420                         Err(e) => {
1421                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1422                         },
1423                 }
1424         }
1425
1426         #[test]
1427         fn parses_offer_with_paths() {
1428                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1429                         .path(BlindedPath {
1430                                 introduction_node_id: pubkey(40),
1431                                 blinding_point: pubkey(41),
1432                                 blinded_hops: vec![
1433                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1434                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1435                                 ],
1436                         })
1437                         .path(BlindedPath {
1438                                 introduction_node_id: pubkey(40),
1439                                 blinding_point: pubkey(41),
1440                                 blinded_hops: vec![
1441                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1442                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1443                                 ],
1444                         })
1445                         .build()
1446                         .unwrap();
1447                 if let Err(e) = offer.to_string().parse::<Offer>() {
1448                         panic!("error parsing offer: {:?}", e);
1449                 }
1450
1451                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1452                 builder.offer.paths = Some(vec![]);
1453
1454                 let offer = builder.build().unwrap();
1455                 if let Err(e) = offer.to_string().parse::<Offer>() {
1456                         panic!("error parsing offer: {:?}", e);
1457                 }
1458         }
1459
1460         #[test]
1461         fn parses_offer_with_quantity() {
1462                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1463                         .supported_quantity(Quantity::One)
1464                         .build()
1465                         .unwrap();
1466                 if let Err(e) = offer.to_string().parse::<Offer>() {
1467                         panic!("error parsing offer: {:?}", e);
1468                 }
1469
1470                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1471                         .supported_quantity(Quantity::Unbounded)
1472                         .build()
1473                         .unwrap();
1474                 if let Err(e) = offer.to_string().parse::<Offer>() {
1475                         panic!("error parsing offer: {:?}", e);
1476                 }
1477
1478                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1479                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1480                         .build()
1481                         .unwrap();
1482                 if let Err(e) = offer.to_string().parse::<Offer>() {
1483                         panic!("error parsing offer: {:?}", e);
1484                 }
1485
1486                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1487                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1488                         .build()
1489                         .unwrap();
1490                 if let Err(e) = offer.to_string().parse::<Offer>() {
1491                         panic!("error parsing offer: {:?}", e);
1492                 }
1493         }
1494
1495         #[test]
1496         fn parses_offer_with_node_id() {
1497                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1498                 if let Err(e) = offer.to_string().parse::<Offer>() {
1499                         panic!("error parsing offer: {:?}", e);
1500                 }
1501
1502                 let mut tlv_stream = offer.as_tlv_stream();
1503                 tlv_stream.node_id = None;
1504
1505                 let mut encoded_offer = Vec::new();
1506                 tlv_stream.write(&mut encoded_offer).unwrap();
1507
1508                 match Offer::try_from(encoded_offer) {
1509                         Ok(_) => panic!("expected error"),
1510                         Err(e) => {
1511                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1512                         },
1513                 }
1514         }
1515
1516         #[test]
1517         fn fails_parsing_offer_with_extra_tlv_records() {
1518                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1519
1520                 let mut encoded_offer = Vec::new();
1521                 offer.write(&mut encoded_offer).unwrap();
1522                 BigSize(80).write(&mut encoded_offer).unwrap();
1523                 BigSize(32).write(&mut encoded_offer).unwrap();
1524                 [42u8; 32].write(&mut encoded_offer).unwrap();
1525
1526                 match Offer::try_from(encoded_offer) {
1527                         Ok(_) => panic!("expected error"),
1528                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1529                 }
1530         }
1531 }
1532
1533 #[cfg(test)]
1534 mod bolt12_tests {
1535         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1536         use crate::ln::msgs::DecodeError;
1537
1538         #[test]
1539         fn parses_bech32_encoded_offers() {
1540                 let offers = [
1541                         // Minimal bolt12 offer
1542                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1543
1544                         // for testnet
1545                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1546
1547                         // for bitcoin (redundant)
1548                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1549
1550                         // for bitcoin or liquidv1
1551                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1552
1553                         // with metadata
1554                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1555
1556                         // with amount
1557                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1558
1559                         // with currency
1560                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1561
1562                         // with expiry
1563                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1564
1565                         // with issuer
1566                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1567
1568                         // with quantity
1569                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1570
1571                         // with unlimited (or unknown) quantity
1572                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1573
1574                         // with single quantity (weird but valid)
1575                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1576
1577                         // with feature
1578                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1579
1580                         // with blinded path via Bob (0x424242...), blinding 020202...
1581                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1582
1583                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1584                         "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",
1585
1586                         // unknown odd field
1587                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1588                 ];
1589                 for encoded_offer in &offers {
1590                         if let Err(e) = encoded_offer.parse::<Offer>() {
1591                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1592                         }
1593                 }
1594         }
1595
1596         #[test]
1597         fn fails_parsing_bech32_encoded_offers() {
1598                 // Malformed: fields out of order
1599                 assert_eq!(
1600                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1601                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1602                 );
1603
1604                 // Malformed: unknown even TLV type 78
1605                 assert_eq!(
1606                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1607                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1608                 );
1609
1610                 // Malformed: empty
1611                 assert_eq!(
1612                         "lno1".parse::<Offer>(),
1613                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1614                 );
1615
1616                 // Malformed: truncated at type
1617                 assert_eq!(
1618                         "lno1pg".parse::<Offer>(),
1619                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1620                 );
1621
1622                 // Malformed: truncated in length
1623                 assert_eq!(
1624                         "lno1pt7s".parse::<Offer>(),
1625                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1626                 );
1627
1628                 // Malformed: truncated after length
1629                 assert_eq!(
1630                         "lno1pgpq".parse::<Offer>(),
1631                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1632                 );
1633
1634                 // Malformed: truncated in description
1635                 assert_eq!(
1636                         "lno1pgpyz".parse::<Offer>(),
1637                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1638                 );
1639
1640                 // Malformed: invalid offer_chains length
1641                 assert_eq!(
1642                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1643                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1644                 );
1645
1646                 // Malformed: truncated currency UTF-8
1647                 assert_eq!(
1648                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1649                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1650                 );
1651
1652                 // Malformed: invalid currency UTF-8
1653                 assert_eq!(
1654                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1655                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1656                 );
1657
1658                 // Malformed: truncated description UTF-8
1659                 assert_eq!(
1660                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1661                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1662                 );
1663
1664                 // Malformed: invalid description UTF-8
1665                 assert_eq!(
1666                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1667                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1668                 );
1669
1670                 // Malformed: truncated offer_paths
1671                 assert_eq!(
1672                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1673                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1674                 );
1675
1676                 // Malformed: zero num_hops in blinded_path
1677                 assert_eq!(
1678                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1679                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1680                 );
1681
1682                 // Malformed: truncated onionmsg_hop in blinded_path
1683                 assert_eq!(
1684                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1685                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1686                 );
1687
1688                 // Malformed: bad first_node_id in blinded_path
1689                 assert_eq!(
1690                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1691                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1692                 );
1693
1694                 // Malformed: bad blinding in blinded_path
1695                 assert_eq!(
1696                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1697                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1698                 );
1699
1700                 // Malformed: bad blinded_node_id in onionmsg_hop
1701                 assert_eq!(
1702                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1703                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1704                 );
1705
1706                 // Malformed: truncated issuer UTF-8
1707                 assert_eq!(
1708                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1709                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1710                 );
1711
1712                 // Malformed: invalid issuer UTF-8
1713                 assert_eq!(
1714                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1715                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1716                 );
1717
1718                 // Malformed: invalid offer_node_id
1719                 assert_eq!(
1720                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
1721                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1722                 );
1723
1724                 // Contains type >= 80
1725                 assert_eq!(
1726                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1727                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1728                 );
1729
1730                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
1731                 // Contains unknown feature 22
1732                 assert!(
1733                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
1734                 );
1735
1736                 // Missing offer_description
1737                 assert_eq!(
1738                         "lno1zcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese".parse::<Offer>(),
1739                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1740                 );
1741
1742                 // Missing offer_node_id"
1743                 assert_eq!(
1744                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
1745                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1746                 );
1747         }
1748 }