_ 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 //! ```ignore
  17 //! extern crate bitcoin;
  18 //! extern crate core;
  19 //! extern crate lightning;
  20 //!
  21 //! use core::convert::TryFrom;
  22 //! use core::num::NonZeroU64;
  23 //! use core::time::Duration;
  24 //!
  25 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  26 //! use lightning::offers::offer::{Offer, OfferBuilder, Quantity};
  27 //! use lightning::offers::parse::ParseError;
  28 //! use lightning::util::ser::{Readable, Writeable};
  29 //!
  30 //! # use lightning::onion_message::BlindedPath;
  31 //! # #[cfg(feature = "std")]
  32 //! # use std::time::SystemTime;
  33 //! #
  34 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
  35 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
  36 //! #
  37 //! # #[cfg(feature = "std")]
  38 //! # fn build() -> Result<(), ParseError> {
  39 //! let secp_ctx = Secp256k1::new();
  40 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
  41 //! let pubkey = PublicKey::from(keys);
  42 //!
  43 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
  44 //! let offer = OfferBuilder::new("coffee, large".to_string(), pubkey)
  45 //!     .amount_msats(20_000)
  46 //!     .supported_quantity(Quantity::Unbounded)
  47 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  48 //!     .issuer("Foo Bar".to_string())
  49 //!     .path(create_blinded_path())
  50 //!     .path(create_another_blinded_path())
  51 //!     .build()?;
  52 //!
  53 //! // Encode as a bech32 string for use in a QR code.
  54 //! let encoded_offer = offer.to_string();
  55 //!
  56 //! // Parse from a bech32 string after scanning from a QR code.
  57 //! let offer = encoded_offer.parse::<Offer>()?;
  58 //!
  59 //! // Encode offer as raw bytes.
  60 //! let mut bytes = Vec::new();
  61 //! offer.write(&mut bytes).unwrap();
  62 //!
  63 //! // Decode raw bytes into an offer.
  64 //! let offer = Offer::try_from(bytes)?;
  65 //! # Ok(())
  66 //! # }
  67 //! ```
  68
  69 use bitcoin::blockdata::constants::ChainHash;
  70 use bitcoin::network::constants::Network;
  71 use bitcoin::secp256k1::PublicKey;
  72 use core::convert::TryFrom;
  73 use core::num::NonZeroU64;
  74 use core::str::FromStr;
  75 use core::time::Duration;
  76 use crate::io;
  77 use crate::ln::features::OfferFeatures;
  78 use crate::ln::msgs::MAX_VALUE_MSAT;
  79 use crate::offers::invoice_request::InvoiceRequestBuilder;
  80 use crate::offers::parse::{Bech32Encode, ParseError, ParsedMessage, SemanticError};
  81 use crate::onion_message::BlindedPath;
  82 use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
  83 use crate::util::string::PrintableString;
  84
  85 use crate::prelude::*;
  86
  87 #[cfg(feature = "std")]
  88 use std::time::SystemTime;
  89
  90 /// Builds an [`Offer`] for the "offer to be paid" flow.
  91 ///
  92 /// See [module-level documentation] for usage.
  93 ///
  94 /// [module-level documentation]: self
  95 pub struct OfferBuilder {
  96         offer: OfferContents,
  97 }
  98
  99 impl OfferBuilder {
 100         /// Creates a new builder for an offer setting the [`Offer::description`] and using the
 101         /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
 102         /// while the offer is valid.
 103         ///
 104         /// Use a different pubkey per offer to avoid correlating offers.
 105         pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
 106                 let offer = OfferContents {
 107                         chains: None, metadata: None, amount: None, description,
 108                         features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 109                         supported_quantity: Quantity::one(), signing_pubkey: Some(signing_pubkey),
 110                 };
 111                 OfferBuilder { offer }
 112         }
 113
 114         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 115         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 116         ///
 117         /// See [`Offer::chains`] on how this relates to the payment currency.
 118         ///
 119         /// Successive calls to this method will add another chain hash.
 120         pub fn chain(mut self, network: Network) -> Self {
 121                 let chains = self.offer.chains.get_or_insert_with(Vec::new);
 122                 let chain = ChainHash::using_genesis_block(network);
 123                 if !chains.contains(&chain) {
 124                         chains.push(chain);
 125                 }
 126
 127                 self
 128         }
 129
 130         /// Sets the [`Offer::metadata`].
 131         ///
 132         /// Successive calls to this method will override the previous setting.
 133         pub fn metadata(mut self, metadata: Vec<u8>) -> Self {
 134                 self.offer.metadata = Some(metadata);
 135                 self
 136         }
 137
 138         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 139         ///
 140         /// Successive calls to this method will override the previous setting.
 141         pub fn amount_msats(self, amount_msats: u64) -> Self {
 142                 self.amount(Amount::Bitcoin { amount_msats })
 143         }
 144
 145         /// Sets the [`Offer::amount`].
 146         ///
 147         /// Successive calls to this method will override the previous setting.
 148         pub(super) fn amount(mut self, amount: Amount) -> Self {
 149                 self.offer.amount = Some(amount);
 150                 self
 151         }
 152
 153         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 154         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 155         ///
 156         /// Successive calls to this method will override the previous setting.
 157         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 158                 self.offer.absolute_expiry = Some(absolute_expiry);
 159                 self
 160         }
 161
 162         /// Sets the [`Offer::issuer`].
 163         ///
 164         /// Successive calls to this method will override the previous setting.
 165         pub fn issuer(mut self, issuer: String) -> Self {
 166                 self.offer.issuer = Some(issuer);
 167                 self
 168         }
 169
 170         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 171         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 172         ///
 173         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 174         /// adding duplicate paths.
 175         pub fn path(mut self, path: BlindedPath) -> Self {
 176                 self.offer.paths.get_or_insert_with(Vec::new).push(path);
 177                 self
 178         }
 179
 180         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 181         /// [`Quantity::one`].
 182         ///
 183         /// Successive calls to this method will override the previous setting.
 184         pub fn supported_quantity(mut self, quantity: Quantity) -> Self {
 185                 self.offer.supported_quantity = quantity;
 186                 self
 187         }
 188
 189         /// Builds an [`Offer`] from the builder's settings.
 190         pub fn build(mut self) -> Result<Offer, SemanticError> {
 191                 match self.offer.amount {
 192                         Some(Amount::Bitcoin { amount_msats }) => {
 193                                 if amount_msats > MAX_VALUE_MSAT {
 194                                         return Err(SemanticError::InvalidAmount);
 195                                 }
 196                         },
 197                         Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
 198                         None => {},
 199                 }
 200
 201                 if let Some(chains) = &self.offer.chains {
 202                         if chains.len() == 1 && chains[0] == self.offer.implied_chain() {
 203                                 self.offer.chains = None;
 204                         }
 205                 }
 206
 207                 let mut bytes = Vec::new();
 208                 self.offer.write(&mut bytes).unwrap();
 209
 210                 Ok(Offer {
 211                         bytes,
 212                         contents: self.offer,
 213                 })
 214         }
 215 }
 216
 217 #[cfg(test)]
 218 impl OfferBuilder {
 219         fn features_unchecked(mut self, features: OfferFeatures) -> Self {
 220                 self.offer.features = features;
 221                 self
 222         }
 223
 224         pub(super) fn build_unchecked(self) -> Offer {
 225                 let mut bytes = Vec::new();
 226                 self.offer.write(&mut bytes).unwrap();
 227
 228                 Offer { bytes, contents: self.offer }
 229         }
 230 }
 231
 232 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 233 ///
 234 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 235 /// customer may request an `Invoice` for a specific quantity and using an amount sufficient to
 236 /// cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 237 ///
 238 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 239 /// latter.
 240 ///
 241 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 242 ///
 243 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 244 #[derive(Clone, Debug)]
 245 pub struct Offer {
 246         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 247         // fields.
 248         pub(super) bytes: Vec<u8>,
 249         pub(super) contents: OfferContents,
 250 }
 251
 252 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or an `Invoice`.
 253 ///
 254 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 255 #[derive(Clone, Debug)]
 256 pub(super) struct OfferContents {
 257         chains: Option<Vec<ChainHash>>,
 258         metadata: Option<Vec<u8>>,
 259         amount: Option<Amount>,
 260         description: String,
 261         features: OfferFeatures,
 262         absolute_expiry: Option<Duration>,
 263         issuer: Option<String>,
 264         paths: Option<Vec<BlindedPath>>,
 265         supported_quantity: Quantity,
 266         signing_pubkey: Option<PublicKey>,
 267 }
 268
 269 impl Offer {
 270         // TODO: Return a slice once ChainHash has constants.
 271         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 272         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 273         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 274         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 275         /// for the selected chain.
 276         pub fn chains(&self) -> Vec<ChainHash> {
 277                 self.contents.chains()
 278         }
 279
 280         pub(super) fn implied_chain(&self) -> ChainHash {
 281                 self.contents.implied_chain()
 282         }
 283
 284         /// Returns whether the given chain is supported by the offer.
 285         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 286                 self.contents.supports_chain(chain)
 287         }
 288
 289         // TODO: Link to corresponding method in `InvoiceRequest`.
 290         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 291         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 292         pub fn metadata(&self) -> Option<&Vec<u8>> {
 293                 self.contents.metadata.as_ref()
 294         }
 295
 296         /// The minimum amount required for a successful payment of a single item.
 297         pub fn amount(&self) -> Option<&Amount> {
 298                 self.contents.amount()
 299         }
 300
 301         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 302         /// but with the caveat that it has not been verified in any way.
 303         pub fn description(&self) -> PrintableString {
 304                 PrintableString(&self.contents.description)
 305         }
 306
 307         /// Features pertaining to the offer.
 308         pub fn features(&self) -> &OfferFeatures {
 309                 &self.contents.features
 310         }
 311
 312         /// Duration since the Unix epoch when an invoice should no longer be requested.
 313         ///
 314         /// If `None`, the offer does not expire.
 315         pub fn absolute_expiry(&self) -> Option<Duration> {
 316                 self.contents.absolute_expiry
 317         }
 318
 319         /// Whether the offer has expired.
 320         #[cfg(feature = "std")]
 321         pub fn is_expired(&self) -> bool {
 322                 match self.absolute_expiry() {
 323                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 324                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 325                                 Err(_) => false,
 326                         },
 327                         None => false,
 328                 }
 329         }
 330
 331         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 332         /// displayed to the user but with the caveat that it has not been verified in any way.
 333         pub fn issuer(&self) -> Option<PrintableString> {
 334                 self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 335         }
 336
 337         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 338         /// recipient privacy by obfuscating its node id.
 339         pub fn paths(&self) -> &[BlindedPath] {
 340                 self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 341         }
 342
 343         /// The quantity of items supported.
 344         pub fn supported_quantity(&self) -> Quantity {
 345                 self.contents.supported_quantity()
 346         }
 347
 348         /// Returns whether the given quantity is valid for the offer.
 349         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 350                 self.contents.is_valid_quantity(quantity)
 351         }
 352
 353         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 354         ///
 355         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 356         pub fn expects_quantity(&self) -> bool {
 357                 self.contents.expects_quantity()
 358         }
 359
 360         /// The public key used by the recipient to sign invoices.
 361         pub fn signing_pubkey(&self) -> PublicKey {
 362                 self.contents.signing_pubkey.unwrap()
 363         }
 364
 365         /// Creates an [`InvoiceRequest`] for the offer with the given `metadata` and `payer_id`, which
 366         /// will be reflected in the `Invoice` response.
 367         ///
 368         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 369         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 370         /// hashing in the signature calculation.
 371         ///
 372         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 373         /// Otherwise, payments may be correlated.
 374         ///
 375         /// Errors if the offer contains unknown required features.
 376         ///
 377         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 378         pub fn request_invoice(
 379                 &self, metadata: Vec<u8>, payer_id: PublicKey
 380         ) -> Result<InvoiceRequestBuilder, SemanticError> {
 381                 if self.features().requires_unknown_bits() {
 382                         return Err(SemanticError::UnknownRequiredFeatures);
 383                 }
 384
 385                 Ok(InvoiceRequestBuilder::new(self, metadata, payer_id))
 386         }
 387
 388         #[cfg(test)]
 389         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 390                 self.contents.as_tlv_stream()
 391         }
 392 }
 393
 394 impl AsRef<[u8]> for Offer {
 395         fn as_ref(&self) -> &[u8] {
 396                 &self.bytes
 397         }
 398 }
 399
 400 impl OfferContents {
 401         pub fn chains(&self) -> Vec<ChainHash> {
 402                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 403         }
 404
 405         pub fn implied_chain(&self) -> ChainHash {
 406                 ChainHash::using_genesis_block(Network::Bitcoin)
 407         }
 408
 409         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 410                 self.chains().contains(&chain)
 411         }
 412
 413         pub fn amount(&self) -> Option<&Amount> {
 414                 self.amount.as_ref()
 415         }
 416
 417         pub(super) fn check_amount_msats_for_quantity(
 418                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 419         ) -> Result<(), SemanticError> {
 420                 let offer_amount_msats = match self.amount {
 421                         None => 0,
 422                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 423                         Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
 424                 };
 425
 426                 if !self.expects_quantity() || quantity.is_some() {
 427                         let expected_amount_msats = offer_amount_msats * quantity.unwrap_or(1);
 428                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 429
 430                         if amount_msats < expected_amount_msats {
 431                                 return Err(SemanticError::InsufficientAmount);
 432                         }
 433
 434                         if amount_msats > MAX_VALUE_MSAT {
 435                                 return Err(SemanticError::InvalidAmount);
 436                         }
 437                 }
 438
 439                 Ok(())
 440         }
 441
 442         pub fn supported_quantity(&self) -> Quantity {
 443                 self.supported_quantity
 444         }
 445
 446         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), SemanticError> {
 447                 let expects_quantity = self.expects_quantity();
 448                 match quantity {
 449                         None if expects_quantity => Err(SemanticError::MissingQuantity),
 450                         Some(_) if !expects_quantity => Err(SemanticError::UnexpectedQuantity),
 451                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 452                                 Err(SemanticError::InvalidQuantity)
 453                         },
 454                         _ => Ok(()),
 455                 }
 456         }
 457
 458         fn is_valid_quantity(&self, quantity: u64) -> bool {
 459                 match self.supported_quantity {
 460                         Quantity::Bounded(n) => {
 461                                 let n = n.get();
 462                                 if n == 1 { false }
 463                                 else { quantity > 0 && quantity <= n }
 464                         },
 465                         Quantity::Unbounded => quantity > 0,
 466                 }
 467         }
 468
 469         fn expects_quantity(&self) -> bool {
 470                 match self.supported_quantity {
 471                         Quantity::Bounded(n) => n.get() != 1,
 472                         Quantity::Unbounded => true,
 473                 }
 474         }
 475
 476         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 477                 let (currency, amount) = match &self.amount {
 478                         None => (None, None),
 479                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 480                         Some(Amount::Currency { iso4217_code, amount }) => (
 481                                 Some(iso4217_code), Some(*amount)
 482                         ),
 483                 };
 484
 485                 let features = {
 486                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 487                 };
 488
 489                 OfferTlvStreamRef {
 490                         chains: self.chains.as_ref(),
 491                         metadata: self.metadata.as_ref(),
 492                         currency,
 493                         amount,
 494                         description: Some(&self.description),
 495                         features,
 496                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 497                         paths: self.paths.as_ref(),
 498                         issuer: self.issuer.as_ref(),
 499                         quantity_max: self.supported_quantity.to_tlv_record(),
 500                         node_id: self.signing_pubkey.as_ref(),
 501                 }
 502         }
 503 }
 504
 505 impl Writeable for Offer {
 506         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 507                 WithoutLength(&self.bytes).write(writer)
 508         }
 509 }
 510
 511 impl Writeable for OfferContents {
 512         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 513                 self.as_tlv_stream().write(writer)
 514         }
 515 }
 516
 517 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 518 /// another currency.
 519 #[derive(Clone, Debug, PartialEq)]
 520 pub enum Amount {
 521         /// An amount of bitcoin.
 522         Bitcoin {
 523                 /// The amount in millisatoshi.
 524                 amount_msats: u64,
 525         },
 526         /// An amount of currency specified using ISO 4712.
 527         Currency {
 528                 /// The currency that the amount is denominated in.
 529                 iso4217_code: CurrencyCode,
 530                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 531                 amount: u64,
 532         },
 533 }
 534
 535 /// An ISO 4712 three-letter currency code (e.g., USD).
 536 pub type CurrencyCode = [u8; 3];
 537
 538 /// Quantity of items supported by an [`Offer`].
 539 #[derive(Clone, Copy, Debug, PartialEq)]
 540 pub enum Quantity {
 541         /// Up to a specific number of items (inclusive).
 542         Bounded(NonZeroU64),
 543         /// One or more items.
 544         Unbounded,
 545 }
 546
 547 impl Quantity {
 548         /// The default quantity of one.
 549         pub fn one() -> Self {
 550                 Quantity::Bounded(NonZeroU64::new(1).unwrap())
 551         }
 552
 553         fn to_tlv_record(&self) -> Option<u64> {
 554                 match self {
 555                         Quantity::Bounded(n) => {
 556                                 let n = n.get();
 557                                 if n == 1 { None } else { Some(n) }
 558                         },
 559                         Quantity::Unbounded => Some(0),
 560                 }
 561         }
 562 }
 563
 564 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, 1..80, {
 565         (2, chains: (Vec<ChainHash>, WithoutLength)),
 566         (4, metadata: (Vec<u8>, WithoutLength)),
 567         (6, currency: CurrencyCode),
 568         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 569         (10, description: (String, WithoutLength)),
 570         (12, features: OfferFeatures),
 571         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 572         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 573         (18, issuer: (String, WithoutLength)),
 574         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 575         (22, node_id: PublicKey),
 576 });
 577
 578 impl Bech32Encode for Offer {
 579         const BECH32_HRP: &'static str = "lno";
 580 }
 581
 582 impl FromStr for Offer {
 583         type Err = ParseError;
 584
 585         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 586                 Self::from_bech32_str(s)
 587         }
 588 }
 589
 590 impl TryFrom<Vec<u8>> for Offer {
 591         type Error = ParseError;
 592
 593         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 594                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
 595                 let ParsedMessage { bytes, tlv_stream } = offer;
 596                 let contents = OfferContents::try_from(tlv_stream)?;
 597                 Ok(Offer { bytes, contents })
 598         }
 599 }
 600
 601 impl TryFrom<OfferTlvStream> for OfferContents {
 602         type Error = SemanticError;
 603
 604         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 605                 let OfferTlvStream {
 606                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 607                         issuer, quantity_max, node_id,
 608                 } = tlv_stream;
 609
 610                 let amount = match (currency, amount) {
 611                         (None, None) => None,
 612                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
 613                                 return Err(SemanticError::InvalidAmount);
 614                         },
 615                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 616                         (Some(_), None) => return Err(SemanticError::MissingAmount),
 617                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
 618                 };
 619
 620                 let description = match description {
 621                         None => return Err(SemanticError::MissingDescription),
 622                         Some(description) => description,
 623                 };
 624
 625                 let features = features.unwrap_or_else(OfferFeatures::empty);
 626
 627                 let absolute_expiry = absolute_expiry
 628                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
 629
 630                 let supported_quantity = match quantity_max {
 631                         None => Quantity::one(),
 632                         Some(0) => Quantity::Unbounded,
 633                         Some(1) => return Err(SemanticError::InvalidQuantity),
 634                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
 635                 };
 636
 637                 if node_id.is_none() {
 638                         return Err(SemanticError::MissingSigningPubkey);
 639                 }
 640
 641                 Ok(OfferContents {
 642                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
 643                         supported_quantity, signing_pubkey: node_id,
 644                 })
 645         }
 646 }
 647
 648 impl core::fmt::Display for Offer {
 649         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 650                 self.fmt_bech32_str(f)
 651         }
 652 }
 653
 654 #[cfg(test)]
 655 mod tests {
 656         use super::{Amount, Offer, OfferBuilder, Quantity};
 657
 658         use bitcoin::blockdata::constants::ChainHash;
 659         use bitcoin::network::constants::Network;
 660         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
 661         use core::convert::TryFrom;
 662         use core::num::NonZeroU64;
 663         use core::time::Duration;
 664         use crate::ln::features::OfferFeatures;
 665         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 666         use crate::offers::parse::{ParseError, SemanticError};
 667         use crate::onion_message::{BlindedHop, BlindedPath};
 668         use crate::util::ser::{BigSize, Writeable};
 669         use crate::util::string::PrintableString;
 670
 671         fn pubkey(byte: u8) -> PublicKey {
 672                 let secp_ctx = Secp256k1::new();
 673                 PublicKey::from_secret_key(&secp_ctx, &privkey(byte))
 674         }
 675
 676         fn privkey(byte: u8) -> SecretKey {
 677                 SecretKey::from_slice(&[byte; 32]).unwrap()
 678         }
 679
 680         #[test]
 681         fn builds_offer_with_defaults() {
 682                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
 683                 let tlv_stream = offer.as_tlv_stream();
 684                 let mut buffer = Vec::new();
 685                 offer.write(&mut buffer).unwrap();
 686
 687                 assert_eq!(offer.bytes, buffer.as_slice());
 688                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
 689                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
 690                 assert_eq!(offer.metadata(), None);
 691                 assert_eq!(offer.amount(), None);
 692                 assert_eq!(offer.description(), PrintableString("foo"));
 693                 assert_eq!(offer.features(), &OfferFeatures::empty());
 694                 assert_eq!(offer.absolute_expiry(), None);
 695                 #[cfg(feature = "std")]
 696                 assert!(!offer.is_expired());
 697                 assert_eq!(offer.paths(), &[]);
 698                 assert_eq!(offer.issuer(), None);
 699                 assert_eq!(offer.supported_quantity(), Quantity::one());
 700                 assert_eq!(offer.signing_pubkey(), pubkey(42));
 701
 702                 assert_eq!(tlv_stream.chains, None);
 703                 assert_eq!(tlv_stream.metadata, None);
 704                 assert_eq!(tlv_stream.currency, None);
 705                 assert_eq!(tlv_stream.amount, None);
 706                 assert_eq!(tlv_stream.description, Some(&String::from("foo")));
 707                 assert_eq!(tlv_stream.features, None);
 708                 assert_eq!(tlv_stream.absolute_expiry, None);
 709                 assert_eq!(tlv_stream.paths, None);
 710                 assert_eq!(tlv_stream.issuer, None);
 711                 assert_eq!(tlv_stream.quantity_max, None);
 712                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
 713
 714                 if let Err(e) = Offer::try_from(buffer) {
 715                         panic!("error parsing offer: {:?}", e);
 716                 }
 717         }
 718
 719         #[test]
 720         fn builds_offer_with_chains() {
 721                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 722                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 723
 724                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 725                         .chain(Network::Bitcoin)
 726                         .build()
 727                         .unwrap();
 728                 assert!(offer.supports_chain(mainnet));
 729                 assert_eq!(offer.chains(), vec![mainnet]);
 730                 assert_eq!(offer.as_tlv_stream().chains, None);
 731
 732                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 733                         .chain(Network::Testnet)
 734                         .build()
 735                         .unwrap();
 736                 assert!(offer.supports_chain(testnet));
 737                 assert_eq!(offer.chains(), vec![testnet]);
 738                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
 739
 740                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 741                         .chain(Network::Testnet)
 742                         .chain(Network::Testnet)
 743                         .build()
 744                         .unwrap();
 745                 assert!(offer.supports_chain(testnet));
 746                 assert_eq!(offer.chains(), vec![testnet]);
 747                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
 748
 749                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 750                         .chain(Network::Bitcoin)
 751                         .chain(Network::Testnet)
 752                         .build()
 753                         .unwrap();
 754                 assert!(offer.supports_chain(mainnet));
 755                 assert!(offer.supports_chain(testnet));
 756                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
 757                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
 758         }
 759
 760         #[test]
 761         fn builds_offer_with_metadata() {
 762                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 763                         .metadata(vec![42; 32])
 764                         .build()
 765                         .unwrap();
 766                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
 767                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
 768
 769                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 770                         .metadata(vec![42; 32])
 771                         .metadata(vec![43; 32])
 772                         .build()
 773                         .unwrap();
 774                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
 775                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
 776         }
 777
 778         #[test]
 779         fn builds_offer_with_amount() {
 780                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
 781                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
 782
 783                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 784                         .amount_msats(1000)
 785                         .build()
 786                         .unwrap();
 787                 let tlv_stream = offer.as_tlv_stream();
 788                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
 789                 assert_eq!(tlv_stream.amount, Some(1000));
 790                 assert_eq!(tlv_stream.currency, None);
 791
 792                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
 793                         .amount(currency_amount.clone());
 794                 let tlv_stream = builder.offer.as_tlv_stream();
 795                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
 796                 assert_eq!(tlv_stream.amount, Some(10));
 797                 assert_eq!(tlv_stream.currency, Some(b"USD"));
 798                 match builder.build() {
 799                         Ok(_) => panic!("expected error"),
 800                         Err(e) => assert_eq!(e, SemanticError::UnsupportedCurrency),
 801                 }
 802
 803                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 804                         .amount(currency_amount.clone())
 805                         .amount(bitcoin_amount.clone())
 806                         .build()
 807                         .unwrap();
 808                 let tlv_stream = offer.as_tlv_stream();
 809                 assert_eq!(tlv_stream.amount, Some(1000));
 810                 assert_eq!(tlv_stream.currency, None);
 811
 812                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
 813                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
 814                         Ok(_) => panic!("expected error"),
 815                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
 816                 }
 817         }
 818
 819         #[test]
 820         fn builds_offer_with_features() {
 821                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 822                         .features_unchecked(OfferFeatures::unknown())
 823                         .build()
 824                         .unwrap();
 825                 assert_eq!(offer.features(), &OfferFeatures::unknown());
 826                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
 827
 828                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 829                         .features_unchecked(OfferFeatures::unknown())
 830                         .features_unchecked(OfferFeatures::empty())
 831                         .build()
 832                         .unwrap();
 833                 assert_eq!(offer.features(), &OfferFeatures::empty());
 834                 assert_eq!(offer.as_tlv_stream().features, None);
 835         }
 836
 837         #[test]
 838         fn builds_offer_with_absolute_expiry() {
 839                 let future_expiry = Duration::from_secs(u64::max_value());
 840                 let past_expiry = Duration::from_secs(0);
 841
 842                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 843                         .absolute_expiry(future_expiry)
 844                         .build()
 845                         .unwrap();
 846                 #[cfg(feature = "std")]
 847                 assert!(!offer.is_expired());
 848                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
 849                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
 850
 851                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 852                         .absolute_expiry(future_expiry)
 853                         .absolute_expiry(past_expiry)
 854                         .build()
 855                         .unwrap();
 856                 #[cfg(feature = "std")]
 857                 assert!(offer.is_expired());
 858                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
 859                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
 860         }
 861
 862         #[test]
 863         fn builds_offer_with_paths() {
 864                 let paths = vec![
 865                         BlindedPath {
 866                                 introduction_node_id: pubkey(40),
 867                                 blinding_point: pubkey(41),
 868                                 blinded_hops: vec![
 869                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 870                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 871                                 ],
 872                         },
 873                         BlindedPath {
 874                                 introduction_node_id: pubkey(40),
 875                                 blinding_point: pubkey(41),
 876                                 blinded_hops: vec![
 877                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 878                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 879                                 ],
 880                         },
 881                 ];
 882
 883                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 884                         .path(paths[0].clone())
 885                         .path(paths[1].clone())
 886                         .build()
 887                         .unwrap();
 888                 let tlv_stream = offer.as_tlv_stream();
 889                 assert_eq!(offer.paths(), paths.as_slice());
 890                 assert_eq!(offer.signing_pubkey(), pubkey(42));
 891                 assert_ne!(pubkey(42), pubkey(44));
 892                 assert_eq!(tlv_stream.paths, Some(&paths));
 893                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
 894         }
 895
 896         #[test]
 897         fn builds_offer_with_issuer() {
 898                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 899                         .issuer("bar".into())
 900                         .build()
 901                         .unwrap();
 902                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
 903                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
 904
 905                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 906                         .issuer("bar".into())
 907                         .issuer("baz".into())
 908                         .build()
 909                         .unwrap();
 910                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
 911                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
 912         }
 913
 914         #[test]
 915         fn builds_offer_with_supported_quantity() {
 916                 let ten = NonZeroU64::new(10).unwrap();
 917
 918                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 919                         .supported_quantity(Quantity::one())
 920                         .build()
 921                         .unwrap();
 922                 let tlv_stream = offer.as_tlv_stream();
 923                 assert_eq!(offer.supported_quantity(), Quantity::one());
 924                 assert_eq!(tlv_stream.quantity_max, None);
 925
 926                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 927                         .supported_quantity(Quantity::Unbounded)
 928                         .build()
 929                         .unwrap();
 930                 let tlv_stream = offer.as_tlv_stream();
 931                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
 932                 assert_eq!(tlv_stream.quantity_max, Some(0));
 933
 934                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 935                         .supported_quantity(Quantity::Bounded(ten))
 936                         .build()
 937                         .unwrap();
 938                 let tlv_stream = offer.as_tlv_stream();
 939                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
 940                 assert_eq!(tlv_stream.quantity_max, Some(10));
 941
 942                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 943                         .supported_quantity(Quantity::Bounded(ten))
 944                         .supported_quantity(Quantity::one())
 945                         .build()
 946                         .unwrap();
 947                 let tlv_stream = offer.as_tlv_stream();
 948                 assert_eq!(offer.supported_quantity(), Quantity::one());
 949                 assert_eq!(tlv_stream.quantity_max, None);
 950         }
 951
 952         #[test]
 953         fn fails_requesting_invoice_with_unknown_required_features() {
 954                 match OfferBuilder::new("foo".into(), pubkey(42))
 955                         .features_unchecked(OfferFeatures::unknown())
 956                         .build().unwrap()
 957                         .request_invoice(vec![1; 32], pubkey(43))
 958                 {
 959                         Ok(_) => panic!("expected error"),
 960                         Err(e) => assert_eq!(e, SemanticError::UnknownRequiredFeatures),
 961                 }
 962         }
 963
 964         #[test]
 965         fn parses_offer_with_chains() {
 966                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 967                         .chain(Network::Bitcoin)
 968                         .chain(Network::Testnet)
 969                         .build()
 970                         .unwrap();
 971                 if let Err(e) = offer.to_string().parse::<Offer>() {
 972                         panic!("error parsing offer: {:?}", e);
 973                 }
 974         }
 975
 976         #[test]
 977         fn parses_offer_with_amount() {
 978                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 979                         .amount(Amount::Bitcoin { amount_msats: 1000 })
 980                         .build()
 981                         .unwrap();
 982                 if let Err(e) = offer.to_string().parse::<Offer>() {
 983                         panic!("error parsing offer: {:?}", e);
 984                 }
 985
 986                 let mut tlv_stream = offer.as_tlv_stream();
 987                 tlv_stream.amount = Some(1000);
 988                 tlv_stream.currency = Some(b"USD");
 989
 990                 let mut encoded_offer = Vec::new();
 991                 tlv_stream.write(&mut encoded_offer).unwrap();
 992
 993                 if let Err(e) = Offer::try_from(encoded_offer) {
 994                         panic!("error parsing offer: {:?}", e);
 995                 }
 996
 997                 let mut tlv_stream = offer.as_tlv_stream();
 998                 tlv_stream.amount = None;
 999                 tlv_stream.currency = Some(b"USD");
1000
1001                 let mut encoded_offer = Vec::new();
1002                 tlv_stream.write(&mut encoded_offer).unwrap();
1003
1004                 match Offer::try_from(encoded_offer) {
1005                         Ok(_) => panic!("expected error"),
1006                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount)),
1007                 }
1008
1009                 let mut tlv_stream = offer.as_tlv_stream();
1010                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1011                 tlv_stream.currency = None;
1012
1013                 let mut encoded_offer = Vec::new();
1014                 tlv_stream.write(&mut encoded_offer).unwrap();
1015
1016                 match Offer::try_from(encoded_offer) {
1017                         Ok(_) => panic!("expected error"),
1018                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidAmount)),
1019                 }
1020         }
1021
1022         #[test]
1023         fn parses_offer_with_description() {
1024                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1025                 if let Err(e) = offer.to_string().parse::<Offer>() {
1026                         panic!("error parsing offer: {:?}", e);
1027                 }
1028
1029                 let mut tlv_stream = offer.as_tlv_stream();
1030                 tlv_stream.description = None;
1031
1032                 let mut encoded_offer = Vec::new();
1033                 tlv_stream.write(&mut encoded_offer).unwrap();
1034
1035                 match Offer::try_from(encoded_offer) {
1036                         Ok(_) => panic!("expected error"),
1037                         Err(e) => {
1038                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingDescription));
1039                         },
1040                 }
1041         }
1042
1043         #[test]
1044         fn parses_offer_with_paths() {
1045                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1046                         .path(BlindedPath {
1047                                 introduction_node_id: pubkey(40),
1048                                 blinding_point: pubkey(41),
1049                                 blinded_hops: vec![
1050                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1051                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1052                                 ],
1053                         })
1054                         .path(BlindedPath {
1055                                 introduction_node_id: pubkey(40),
1056                                 blinding_point: pubkey(41),
1057                                 blinded_hops: vec![
1058                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1059                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1060                                 ],
1061                         })
1062                         .build()
1063                         .unwrap();
1064                 if let Err(e) = offer.to_string().parse::<Offer>() {
1065                         panic!("error parsing offer: {:?}", e);
1066                 }
1067
1068                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1069                 builder.offer.paths = Some(vec![]);
1070
1071                 let offer = builder.build().unwrap();
1072                 if let Err(e) = offer.to_string().parse::<Offer>() {
1073                         panic!("error parsing offer: {:?}", e);
1074                 }
1075         }
1076
1077         #[test]
1078         fn parses_offer_with_quantity() {
1079                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1080                         .supported_quantity(Quantity::one())
1081                         .build()
1082                         .unwrap();
1083                 if let Err(e) = offer.to_string().parse::<Offer>() {
1084                         panic!("error parsing offer: {:?}", e);
1085                 }
1086
1087                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1088                         .supported_quantity(Quantity::Unbounded)
1089                         .build()
1090                         .unwrap();
1091                 if let Err(e) = offer.to_string().parse::<Offer>() {
1092                         panic!("error parsing offer: {:?}", e);
1093                 }
1094
1095                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1096                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1097                         .build()
1098                         .unwrap();
1099                 if let Err(e) = offer.to_string().parse::<Offer>() {
1100                         panic!("error parsing offer: {:?}", e);
1101                 }
1102
1103                 let mut tlv_stream = offer.as_tlv_stream();
1104                 tlv_stream.quantity_max = Some(1);
1105
1106                 let mut encoded_offer = Vec::new();
1107                 tlv_stream.write(&mut encoded_offer).unwrap();
1108
1109                 match Offer::try_from(encoded_offer) {
1110                         Ok(_) => panic!("expected error"),
1111                         Err(e) => {
1112                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidQuantity));
1113                         },
1114                 }
1115         }
1116
1117         #[test]
1118         fn parses_offer_with_node_id() {
1119                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1120                 if let Err(e) = offer.to_string().parse::<Offer>() {
1121                         panic!("error parsing offer: {:?}", e);
1122                 }
1123
1124                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1125                 builder.offer.signing_pubkey = None;
1126
1127                 let offer = builder.build().unwrap();
1128                 match offer.to_string().parse::<Offer>() {
1129                         Ok(_) => panic!("expected error"),
1130                         Err(e) => {
1131                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingSigningPubkey));
1132                         },
1133                 }
1134         }
1135
1136         #[test]
1137         fn fails_parsing_offer_with_extra_tlv_records() {
1138                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1139
1140                 let mut encoded_offer = Vec::new();
1141                 offer.write(&mut encoded_offer).unwrap();
1142                 BigSize(80).write(&mut encoded_offer).unwrap();
1143                 BigSize(32).write(&mut encoded_offer).unwrap();
1144                 [42u8; 32].write(&mut encoded_offer).unwrap();
1145
1146                 match Offer::try_from(encoded_offer) {
1147                         Ok(_) => panic!("expected error"),
1148                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1149                 }
1150         }
1151 }
1152
1153 #[cfg(test)]
1154 mod bech32_tests {
1155         use super::{Offer, ParseError};
1156         use bitcoin::bech32;
1157         use crate::ln::msgs::DecodeError;
1158
1159         // TODO: Remove once test vectors are updated.
1160         #[ignore]
1161         #[test]
1162         fn encodes_offer_as_bech32_without_checksum() {
1163                 let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy";
1164                 let offer = dbg!(encoded_offer.parse::<Offer>().unwrap());
1165                 let reencoded_offer = offer.to_string();
1166                 dbg!(reencoded_offer.parse::<Offer>().unwrap());
1167                 assert_eq!(reencoded_offer, encoded_offer);
1168         }
1169
1170         // TODO: Remove once test vectors are updated.
1171         #[ignore]
1172         #[test]
1173         fn parses_bech32_encoded_offers() {
1174                 let offers = [
1175                         // BOLT 12 test vectors
1176                         "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1177                         "l+no1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1178                         "l+no1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1179                         "lno1qcp4256ypqpq+86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn0+0fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0+sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qs+y",
1180                         "lno1qcp4256ypqpq+ 86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn0+  0fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0+\nsqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43l+\r\nastpwuh73k29qs+\r  y",
1181                         // Two blinded paths
1182                         "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",
1183                 ];
1184                 for encoded_offer in &offers {
1185                         if let Err(e) = encoded_offer.parse::<Offer>() {
1186                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1187                         }
1188                 }
1189         }
1190
1191         #[test]
1192         fn fails_parsing_bech32_encoded_offers_with_invalid_continuations() {
1193                 let offers = [
1194                         // BOLT 12 test vectors
1195                         "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy+",
1196                         "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy+ ",
1197                         "+lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1198                         "+ lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1199                         "ln++o1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1200                 ];
1201                 for encoded_offer in &offers {
1202                         match encoded_offer.parse::<Offer>() {
1203                                 Ok(_) => panic!("Valid offer: {}", encoded_offer),
1204                                 Err(e) => assert_eq!(e, ParseError::InvalidContinuation),
1205                         }
1206                 }
1207
1208         }
1209
1210         #[test]
1211         fn fails_parsing_bech32_encoded_offer_with_invalid_hrp() {
1212                 let encoded_offer = "lni1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy";
1213                 match encoded_offer.parse::<Offer>() {
1214                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1215                         Err(e) => assert_eq!(e, ParseError::InvalidBech32Hrp),
1216                 }
1217         }
1218
1219         #[test]
1220         fn fails_parsing_bech32_encoded_offer_with_invalid_bech32_data() {
1221                 let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qso";
1222                 match encoded_offer.parse::<Offer>() {
1223                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1224                         Err(e) => assert_eq!(e, ParseError::Bech32(bech32::Error::InvalidChar('o'))),
1225                 }
1226         }
1227
1228         #[test]
1229         fn fails_parsing_bech32_encoded_offer_with_invalid_tlv_data() {
1230                 let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsyqqqqq";
1231                 match encoded_offer.parse::<Offer>() {
1232                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1233                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1234                 }
1235         }
1236 }