git.bitcoin.ninja 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 //!     .unwrap();
  53 //!
  54 //! // Encode as a bech32 string for use in a QR code.
  55 //! let encoded_offer = offer.to_string();
  56 //!
  57 //! // Parse from a bech32 string after scanning from a QR code.
  58 //! let offer = encoded_offer.parse::<Offer>()?;
  59 //!
  60 //! // Encode offer as raw bytes.
  61 //! let mut bytes = Vec::new();
  62 //! offer.write(&mut bytes).unwrap();
  63 //!
  64 //! // Decode raw bytes into an offer.
  65 //! let offer = Offer::try_from(bytes)?;
  66 //! # Ok(())
  67 //! # }
  68 //! ```
  69
  70 use bitcoin::blockdata::constants::ChainHash;
  71 use bitcoin::network::constants::Network;
  72 use bitcoin::secp256k1::PublicKey;
  73 use core::convert::TryFrom;
  74 use core::num::NonZeroU64;
  75 use core::str::FromStr;
  76 use core::time::Duration;
  77 use crate::io;
  78 use crate::ln::features::OfferFeatures;
  79 use crate::ln::msgs::MAX_VALUE_MSAT;
  80 use crate::offers::parse::{Bech32Encode, ParseError, SemanticError};
  81 use crate::onion_message::BlindedPath;
  82 use crate::util::ser::{HighZeroBytesDroppedBigSize, Readable, 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(mut 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         fn amount(mut self, amount: Amount) -> Self {
 149                 self.offer.amount = Some(amount);
 150                 self
 151         }
 152
 153         /// Sets the [`Offer::features`].
 154         ///
 155         /// Successive calls to this method will override the previous setting.
 156         #[cfg(test)]
 157         pub fn features(mut self, features: OfferFeatures) -> Self {
 158                 self.offer.features = features;
 159                 self
 160         }
 161
 162         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 163         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 164         ///
 165         /// Successive calls to this method will override the previous setting.
 166         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 167                 self.offer.absolute_expiry = Some(absolute_expiry);
 168                 self
 169         }
 170
 171         /// Sets the [`Offer::issuer`].
 172         ///
 173         /// Successive calls to this method will override the previous setting.
 174         pub fn issuer(mut self, issuer: String) -> Self {
 175                 self.offer.issuer = Some(issuer);
 176                 self
 177         }
 178
 179         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 180         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 181         ///
 182         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 183         /// adding duplicate paths.
 184         pub fn path(mut self, path: BlindedPath) -> Self {
 185                 self.offer.paths.get_or_insert_with(Vec::new).push(path);
 186                 self
 187         }
 188
 189         /// Sets the quantity of items for [`Offer::supported_quantity`].
 190         ///
 191         /// Successive calls to this method will override the previous setting.
 192         pub fn supported_quantity(mut self, quantity: Quantity) -> Self {
 193                 self.offer.supported_quantity = quantity;
 194                 self
 195         }
 196
 197         /// Builds an [`Offer`] from the builder's settings.
 198         pub fn build(mut self) -> Result<Offer, ()> {
 199                 match self.offer.amount {
 200                         Some(Amount::Bitcoin { amount_msats }) => {
 201                                 if amount_msats > MAX_VALUE_MSAT {
 202                                         return Err(());
 203                                 }
 204                         },
 205                         Some(Amount::Currency { .. }) => unreachable!(),
 206                         None => {},
 207                 }
 208
 209                 if let Some(chains) = &self.offer.chains {
 210                         if chains.len() == 1 && chains[0] == self.offer.implied_chain() {
 211                                 self.offer.chains = None;
 212                         }
 213                 }
 214
 215                 let mut bytes = Vec::new();
 216                 self.offer.write(&mut bytes).unwrap();
 217
 218                 Ok(Offer {
 219                         bytes,
 220                         contents: self.offer,
 221                 })
 222         }
 223 }
 224
 225 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 226 ///
 227 /// An offer is a precursor to an `InvoiceRequest`. A merchant publishes an offer from which a
 228 /// customer may request an `Invoice` for a specific quantity and using an amount sufficient to
 229 /// cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 230 ///
 231 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 232 /// latter.
 233 ///
 234 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 235 #[derive(Clone, Debug)]
 236 pub struct Offer {
 237         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 238         // fields.
 239         bytes: Vec<u8>,
 240         contents: OfferContents,
 241 }
 242
 243 /// The contents of an [`Offer`], which may be shared with an `InvoiceRequest` or an `Invoice`.
 244 #[derive(Clone, Debug)]
 245 pub(crate) struct OfferContents {
 246         chains: Option<Vec<ChainHash>>,
 247         metadata: Option<Vec<u8>>,
 248         amount: Option<Amount>,
 249         description: String,
 250         features: OfferFeatures,
 251         absolute_expiry: Option<Duration>,
 252         issuer: Option<String>,
 253         paths: Option<Vec<BlindedPath>>,
 254         supported_quantity: Quantity,
 255         signing_pubkey: Option<PublicKey>,
 256 }
 257
 258 impl Offer {
 259         // TODO: Return a slice once ChainHash has constants.
 260         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 261         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 262         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 263         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 264         /// for the selected chain.
 265         pub fn chains(&self) -> Vec<ChainHash> {
 266                 self.contents.chains
 267                         .as_ref()
 268                         .cloned()
 269                         .unwrap_or_else(|| vec![self.contents.implied_chain()])
 270         }
 271
 272         // TODO: Link to corresponding method in `InvoiceRequest`.
 273         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 274         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 275         pub fn metadata(&self) -> Option<&Vec<u8>> {
 276                 self.contents.metadata.as_ref()
 277         }
 278
 279         /// The minimum amount required for a successful payment of a single item.
 280         pub fn amount(&self) -> Option<&Amount> {
 281                 self.contents.amount.as_ref()
 282         }
 283
 284         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 285         /// but with the caveat that it has not been verified in any way.
 286         pub fn description(&self) -> PrintableString {
 287                 PrintableString(&self.contents.description)
 288         }
 289
 290         /// Features pertaining to the offer.
 291         pub fn features(&self) -> &OfferFeatures {
 292                 &self.contents.features
 293         }
 294
 295         /// Duration since the Unix epoch when an invoice should no longer be requested.
 296         ///
 297         /// If `None`, the offer does not expire.
 298         pub fn absolute_expiry(&self) -> Option<Duration> {
 299                 self.contents.absolute_expiry
 300         }
 301
 302         /// Whether the offer has expired.
 303         #[cfg(feature = "std")]
 304         pub fn is_expired(&self) -> bool {
 305                 match self.absolute_expiry() {
 306                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 307                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 308                                 Err(_) => false,
 309                         },
 310                         None => false,
 311                 }
 312         }
 313
 314         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 315         /// displayed to the user but with the caveat that it has not been verified in any way.
 316         pub fn issuer(&self) -> Option<PrintableString> {
 317                 self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 318         }
 319
 320         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 321         /// recipient privacy by obfuscating its node id.
 322         pub fn paths(&self) -> &[BlindedPath] {
 323                 self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 324         }
 325
 326         /// The quantity of items supported.
 327         pub fn supported_quantity(&self) -> Quantity {
 328                 self.contents.supported_quantity()
 329         }
 330
 331         /// The public key used by the recipient to sign invoices.
 332         pub fn signing_pubkey(&self) -> PublicKey {
 333                 self.contents.signing_pubkey.unwrap()
 334         }
 335
 336         #[cfg(test)]
 337         fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 338                 self.contents.as_tlv_stream()
 339         }
 340 }
 341
 342 impl AsRef<[u8]> for Offer {
 343         fn as_ref(&self) -> &[u8] {
 344                 &self.bytes
 345         }
 346 }
 347
 348 impl OfferContents {
 349         pub fn implied_chain(&self) -> ChainHash {
 350                 ChainHash::using_genesis_block(Network::Bitcoin)
 351         }
 352
 353         pub fn supported_quantity(&self) -> Quantity {
 354                 self.supported_quantity
 355         }
 356
 357         fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 358                 let (currency, amount) = match &self.amount {
 359                         None => (None, None),
 360                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 361                         Some(Amount::Currency { iso4217_code, amount }) => (
 362                                 Some(iso4217_code), Some(*amount)
 363                         ),
 364                 };
 365
 366                 let features = {
 367                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 368                 };
 369
 370                 OfferTlvStreamRef {
 371                         chains: self.chains.as_ref(),
 372                         metadata: self.metadata.as_ref(),
 373                         currency,
 374                         amount,
 375                         description: Some(&self.description),
 376                         features,
 377                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 378                         paths: self.paths.as_ref(),
 379                         issuer: self.issuer.as_ref(),
 380                         quantity_max: self.supported_quantity.to_tlv_record(),
 381                         node_id: self.signing_pubkey.as_ref(),
 382                 }
 383         }
 384 }
 385
 386 impl Writeable for Offer {
 387         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 388                 WithoutLength(&self.bytes).write(writer)
 389         }
 390 }
 391
 392 impl Writeable for OfferContents {
 393         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 394                 self.as_tlv_stream().write(writer)
 395         }
 396 }
 397
 398 impl TryFrom<Vec<u8>> for Offer {
 399         type Error = ParseError;
 400
 401         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 402                 let tlv_stream: OfferTlvStream = Readable::read(&mut &bytes[..])?;
 403                 Offer::try_from((bytes, tlv_stream))
 404         }
 405 }
 406
 407 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 408 /// another currency.
 409 #[derive(Clone, Debug, PartialEq)]
 410 pub enum Amount {
 411         /// An amount of bitcoin.
 412         Bitcoin {
 413                 /// The amount in millisatoshi.
 414                 amount_msats: u64,
 415         },
 416         /// An amount of currency specified using ISO 4712.
 417         Currency {
 418                 /// The currency that the amount is denominated in.
 419                 iso4217_code: CurrencyCode,
 420                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 421                 amount: u64,
 422         },
 423 }
 424
 425 /// An ISO 4712 three-letter currency code (e.g., USD).
 426 pub type CurrencyCode = [u8; 3];
 427
 428 /// Quantity of items supported by an [`Offer`].
 429 #[derive(Clone, Copy, Debug, PartialEq)]
 430 pub enum Quantity {
 431         /// Up to a specific number of items (inclusive).
 432         Bounded(NonZeroU64),
 433         /// One or more items.
 434         Unbounded,
 435 }
 436
 437 impl Quantity {
 438         fn one() -> Self {
 439                 Quantity::Bounded(NonZeroU64::new(1).unwrap())
 440         }
 441
 442         fn to_tlv_record(&self) -> Option<u64> {
 443                 match self {
 444                         Quantity::Bounded(n) => {
 445                                 let n = n.get();
 446                                 if n == 1 { None } else { Some(n) }
 447                         },
 448                         Quantity::Unbounded => Some(0),
 449                 }
 450         }
 451 }
 452
 453 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, {
 454         (2, chains: (Vec<ChainHash>, WithoutLength)),
 455         (4, metadata: (Vec<u8>, WithoutLength)),
 456         (6, currency: CurrencyCode),
 457         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 458         (10, description: (String, WithoutLength)),
 459         (12, features: OfferFeatures),
 460         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 461         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 462         (18, issuer: (String, WithoutLength)),
 463         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 464         (22, node_id: PublicKey),
 465 });
 466
 467 impl Bech32Encode for Offer {
 468         const BECH32_HRP: &'static str = "lno";
 469 }
 470
 471 type ParsedOffer = (Vec<u8>, OfferTlvStream);
 472
 473 impl FromStr for Offer {
 474         type Err = ParseError;
 475
 476         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 477                 Self::from_bech32_str(s)
 478         }
 479 }
 480
 481 impl TryFrom<ParsedOffer> for Offer {
 482         type Error = ParseError;
 483
 484         fn try_from(offer: ParsedOffer) -> Result<Self, Self::Error> {
 485                 let (bytes, tlv_stream) = offer;
 486                 let contents = OfferContents::try_from(tlv_stream)?;
 487                 Ok(Offer { bytes, contents })
 488         }
 489 }
 490
 491 impl TryFrom<OfferTlvStream> for OfferContents {
 492         type Error = SemanticError;
 493
 494         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 495                 let OfferTlvStream {
 496                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 497                         issuer, quantity_max, node_id,
 498                 } = tlv_stream;
 499
 500                 let amount = match (currency, amount) {
 501                         (None, None) => None,
 502                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
 503                                 return Err(SemanticError::InvalidAmount);
 504                         },
 505                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 506                         (Some(_), None) => return Err(SemanticError::MissingAmount),
 507                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
 508                 };
 509
 510                 let description = match description {
 511                         None => return Err(SemanticError::MissingDescription),
 512                         Some(description) => description,
 513                 };
 514
 515                 let features = features.unwrap_or_else(OfferFeatures::empty);
 516
 517                 let absolute_expiry = absolute_expiry
 518                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
 519
 520                 let supported_quantity = match quantity_max {
 521                         None => Quantity::one(),
 522                         Some(0) => Quantity::Unbounded,
 523                         Some(1) => return Err(SemanticError::InvalidQuantity),
 524                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
 525                 };
 526
 527                 if node_id.is_none() {
 528                         return Err(SemanticError::MissingSigningPubkey);
 529                 }
 530
 531                 Ok(OfferContents {
 532                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
 533                         supported_quantity, signing_pubkey: node_id,
 534                 })
 535         }
 536 }
 537
 538 impl core::fmt::Display for Offer {
 539         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 540                 self.fmt_bech32_str(f)
 541         }
 542 }
 543
 544 #[cfg(test)]
 545 mod tests {
 546         use super::{Amount, Offer, OfferBuilder, Quantity};
 547
 548         use bitcoin::blockdata::constants::ChainHash;
 549         use bitcoin::network::constants::Network;
 550         use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
 551         use core::convert::TryFrom;
 552         use core::num::NonZeroU64;
 553         use core::time::Duration;
 554         use crate::ln::features::OfferFeatures;
 555         use crate::ln::msgs::MAX_VALUE_MSAT;
 556         use crate::onion_message::{BlindedHop, BlindedPath};
 557         use crate::util::ser::Writeable;
 558         use crate::util::string::PrintableString;
 559
 560         fn pubkey(byte: u8) -> PublicKey {
 561                 let secp_ctx = Secp256k1::new();
 562                 PublicKey::from_secret_key(&secp_ctx, &privkey(byte))
 563         }
 564
 565         fn privkey(byte: u8) -> SecretKey {
 566                 SecretKey::from_slice(&[byte; 32]).unwrap()
 567         }
 568
 569         #[test]
 570         fn builds_offer_with_defaults() {
 571                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
 572                 let tlv_stream = offer.as_tlv_stream();
 573                 let mut buffer = Vec::new();
 574                 offer.write(&mut buffer).unwrap();
 575
 576                 assert_eq!(offer.bytes, buffer.as_slice());
 577                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
 578                 assert_eq!(offer.metadata(), None);
 579                 assert_eq!(offer.amount(), None);
 580                 assert_eq!(offer.description(), PrintableString("foo"));
 581                 assert_eq!(offer.features(), &OfferFeatures::empty());
 582                 assert_eq!(offer.absolute_expiry(), None);
 583                 #[cfg(feature = "std")]
 584                 assert!(!offer.is_expired());
 585                 assert_eq!(offer.paths(), &[]);
 586                 assert_eq!(offer.issuer(), None);
 587                 assert_eq!(offer.supported_quantity(), Quantity::one());
 588                 assert_eq!(offer.signing_pubkey(), pubkey(42));
 589
 590                 assert_eq!(tlv_stream.chains, None);
 591                 assert_eq!(tlv_stream.metadata, None);
 592                 assert_eq!(tlv_stream.currency, None);
 593                 assert_eq!(tlv_stream.amount, None);
 594                 assert_eq!(tlv_stream.description, Some(&String::from("foo")));
 595                 assert_eq!(tlv_stream.features, None);
 596                 assert_eq!(tlv_stream.absolute_expiry, None);
 597                 assert_eq!(tlv_stream.paths, None);
 598                 assert_eq!(tlv_stream.issuer, None);
 599                 assert_eq!(tlv_stream.quantity_max, None);
 600                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
 601
 602                 if let Err(e) = Offer::try_from(buffer) {
 603                         panic!("error parsing offer: {:?}", e);
 604                 }
 605         }
 606
 607         #[test]
 608         fn builds_offer_with_chains() {
 609                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 610                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 611
 612                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 613                         .chain(Network::Bitcoin)
 614                         .build()
 615                         .unwrap();
 616                 assert_eq!(offer.chains(), vec![mainnet]);
 617                 assert_eq!(offer.as_tlv_stream().chains, None);
 618
 619                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 620                         .chain(Network::Testnet)
 621                         .build()
 622                         .unwrap();
 623                 assert_eq!(offer.chains(), vec![testnet]);
 624                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
 625
 626                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 627                         .chain(Network::Testnet)
 628                         .chain(Network::Testnet)
 629                         .build()
 630                         .unwrap();
 631                 assert_eq!(offer.chains(), vec![testnet]);
 632                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
 633
 634                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 635                         .chain(Network::Bitcoin)
 636                         .chain(Network::Testnet)
 637                         .build()
 638                         .unwrap();
 639                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
 640                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
 641         }
 642
 643         #[test]
 644         fn builds_offer_with_metadata() {
 645                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 646                         .metadata(vec![42; 32])
 647                         .build()
 648                         .unwrap();
 649                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
 650                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
 651
 652                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 653                         .metadata(vec![42; 32])
 654                         .metadata(vec![43; 32])
 655                         .build()
 656                         .unwrap();
 657                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
 658                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
 659         }
 660
 661         #[test]
 662         fn builds_offer_with_amount() {
 663                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
 664                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
 665
 666                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 667                         .amount_msats(1000)
 668                         .build()
 669                         .unwrap();
 670                 let tlv_stream = offer.as_tlv_stream();
 671                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
 672                 assert_eq!(tlv_stream.amount, Some(1000));
 673                 assert_eq!(tlv_stream.currency, None);
 674
 675                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
 676                         .amount(currency_amount.clone());
 677                 let tlv_stream = builder.offer.as_tlv_stream();
 678                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
 679                 assert_eq!(tlv_stream.amount, Some(10));
 680                 assert_eq!(tlv_stream.currency, Some(b"USD"));
 681
 682                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 683                         .amount(currency_amount.clone())
 684                         .amount(bitcoin_amount.clone())
 685                         .build()
 686                         .unwrap();
 687                 let tlv_stream = offer.as_tlv_stream();
 688                 assert_eq!(tlv_stream.amount, Some(1000));
 689                 assert_eq!(tlv_stream.currency, None);
 690
 691                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
 692                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
 693                         Ok(_) => panic!("expected error"),
 694                         Err(e) => assert_eq!(e, ()),
 695                 }
 696         }
 697
 698         #[test]
 699         fn builds_offer_with_features() {
 700                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 701                         .features(OfferFeatures::unknown())
 702                         .build()
 703                         .unwrap();
 704                 assert_eq!(offer.features(), &OfferFeatures::unknown());
 705                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
 706
 707                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 708                         .features(OfferFeatures::unknown())
 709                         .features(OfferFeatures::empty())
 710                         .build()
 711                         .unwrap();
 712                 assert_eq!(offer.features(), &OfferFeatures::empty());
 713                 assert_eq!(offer.as_tlv_stream().features, None);
 714         }
 715
 716         #[test]
 717         fn builds_offer_with_absolute_expiry() {
 718                 let future_expiry = Duration::from_secs(u64::max_value());
 719                 let past_expiry = Duration::from_secs(0);
 720
 721                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 722                         .absolute_expiry(future_expiry)
 723                         .build()
 724                         .unwrap();
 725                 #[cfg(feature = "std")]
 726                 assert!(!offer.is_expired());
 727                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
 728                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
 729
 730                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 731                         .absolute_expiry(future_expiry)
 732                         .absolute_expiry(past_expiry)
 733                         .build()
 734                         .unwrap();
 735                 #[cfg(feature = "std")]
 736                 assert!(offer.is_expired());
 737                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
 738                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
 739         }
 740
 741         #[test]
 742         fn builds_offer_with_paths() {
 743                 let paths = vec![
 744                         BlindedPath {
 745                                 introduction_node_id: pubkey(40),
 746                                 blinding_point: pubkey(41),
 747                                 blinded_hops: vec![
 748                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 749                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 750                                 ],
 751                         },
 752                         BlindedPath {
 753                                 introduction_node_id: pubkey(40),
 754                                 blinding_point: pubkey(41),
 755                                 blinded_hops: vec![
 756                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 757                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 758                                 ],
 759                         },
 760                 ];
 761
 762                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 763                         .path(paths[0].clone())
 764                         .path(paths[1].clone())
 765                         .build()
 766                         .unwrap();
 767                 let tlv_stream = offer.as_tlv_stream();
 768                 assert_eq!(offer.paths(), paths.as_slice());
 769                 assert_eq!(offer.signing_pubkey(), pubkey(42));
 770                 assert_ne!(pubkey(42), pubkey(44));
 771                 assert_eq!(tlv_stream.paths, Some(&paths));
 772                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
 773         }
 774
 775         #[test]
 776         fn builds_offer_with_issuer() {
 777                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 778                         .issuer("bar".into())
 779                         .build()
 780                         .unwrap();
 781                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
 782                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
 783
 784                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 785                         .issuer("bar".into())
 786                         .issuer("baz".into())
 787                         .build()
 788                         .unwrap();
 789                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
 790                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
 791         }
 792
 793         #[test]
 794         fn builds_offer_with_supported_quantity() {
 795                 let ten = NonZeroU64::new(10).unwrap();
 796
 797                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 798                         .supported_quantity(Quantity::one())
 799                         .build()
 800                         .unwrap();
 801                 let tlv_stream = offer.as_tlv_stream();
 802                 assert_eq!(offer.supported_quantity(), Quantity::one());
 803                 assert_eq!(tlv_stream.quantity_max, None);
 804
 805                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 806                         .supported_quantity(Quantity::Unbounded)
 807                         .build()
 808                         .unwrap();
 809                 let tlv_stream = offer.as_tlv_stream();
 810                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
 811                 assert_eq!(tlv_stream.quantity_max, Some(0));
 812
 813                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 814                         .supported_quantity(Quantity::Bounded(ten))
 815                         .build()
 816                         .unwrap();
 817                 let tlv_stream = offer.as_tlv_stream();
 818                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
 819                 assert_eq!(tlv_stream.quantity_max, Some(10));
 820
 821                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
 822                         .supported_quantity(Quantity::Bounded(ten))
 823                         .supported_quantity(Quantity::one())
 824                         .build()
 825                         .unwrap();
 826                 let tlv_stream = offer.as_tlv_stream();
 827                 assert_eq!(offer.supported_quantity(), Quantity::one());
 828                 assert_eq!(tlv_stream.quantity_max, None);
 829         }
 830 }
 831
 832 #[cfg(test)]
 833 mod bech32_tests {
 834         use super::{Offer, ParseError};
 835         use bitcoin::bech32;
 836         use crate::ln::msgs::DecodeError;
 837
 838         // TODO: Remove once test vectors are updated.
 839         #[ignore]
 840         #[test]
 841         fn encodes_offer_as_bech32_without_checksum() {
 842                 let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy";
 843                 let offer = dbg!(encoded_offer.parse::<Offer>().unwrap());
 844                 let reencoded_offer = offer.to_string();
 845                 dbg!(reencoded_offer.parse::<Offer>().unwrap());
 846                 assert_eq!(reencoded_offer, encoded_offer);
 847         }
 848
 849         // TODO: Remove once test vectors are updated.
 850         #[ignore]
 851         #[test]
 852         fn parses_bech32_encoded_offers() {
 853                 let offers = [
 854                         // BOLT 12 test vectors
 855                         "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
 856                         "l+no1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
 857                         "l+no1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
 858                         "lno1qcp4256ypqpq+86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn0+0fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0+sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qs+y",
 859                         "lno1qcp4256ypqpq+ 86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn0+  0fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0+\nsqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43l+\r\nastpwuh73k29qs+\r  y",
 860                         // Two blinded paths
 861                         "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",
 862                 ];
 863                 for encoded_offer in &offers {
 864                         if let Err(e) = encoded_offer.parse::<Offer>() {
 865                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
 866                         }
 867                 }
 868         }
 869
 870         #[test]
 871         fn fails_parsing_bech32_encoded_offers_with_invalid_continuations() {
 872                 let offers = [
 873                         // BOLT 12 test vectors
 874                         "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy+",
 875                         "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy+ ",
 876                         "+lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
 877                         "+ lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
 878                         "ln++o1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
 879                 ];
 880                 for encoded_offer in &offers {
 881                         match encoded_offer.parse::<Offer>() {
 882                                 Ok(_) => panic!("Valid offer: {}", encoded_offer),
 883                                 Err(e) => assert_eq!(e, ParseError::InvalidContinuation),
 884                         }
 885                 }
 886
 887         }
 888
 889         #[test]
 890         fn fails_parsing_bech32_encoded_offer_with_invalid_hrp() {
 891                 let encoded_offer = "lni1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy";
 892                 match encoded_offer.parse::<Offer>() {
 893                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
 894                         Err(e) => assert_eq!(e, ParseError::InvalidBech32Hrp),
 895                 }
 896         }
 897
 898         #[test]
 899         fn fails_parsing_bech32_encoded_offer_with_invalid_bech32_data() {
 900                 let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qso";
 901                 match encoded_offer.parse::<Offer>() {
 902                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
 903                         Err(e) => assert_eq!(e, ParseError::Bech32(bech32::Error::InvalidChar('o'))),
 904                 }
 905         }
 906
 907         #[test]
 908         fn fails_parsing_bech32_encoded_offer_with_invalid_tlv_data() {
 909                 let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsyqqqqq";
 910                 match encoded_offer.parse::<Offer>() {
 911                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
 912                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
 913                 }
 914         }
 915 }