_ Git - rust-lightning/blob - lightning/src/offers/offer.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Data structures and encoding for `offer` messages.
  11 //!
  12 //! An [`Offer`] represents an "offer to be paid." It is typically constructed by a merchant and
  13 //! published as a QR code to be scanned by a customer. The customer uses the offer to request an
  14 //! invoice from the merchant to be paid.
  15 //!
  16 //! # Example
  17 //!
  18 //! ```
  19 //! extern crate bitcoin;
  20 //! extern crate core;
  21 //! extern crate lightning;
  22 //!
  23 //! use core::convert::TryFrom;
  24 //! use core::num::NonZeroU64;
  25 //! use core::time::Duration;
  26 //!
  27 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  28 //! use lightning::offers::offer::{Offer, OfferBuilder, Quantity};
  29 //! use lightning::offers::parse::Bolt12ParseError;
  30 //! use lightning::util::ser::{Readable, Writeable};
  31 //!
  32 //! # use lightning::blinded_path::BlindedPath;
  33 //! # #[cfg(feature = "std")]
  34 //! # use std::time::SystemTime;
  35 //! #
  36 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
  37 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
  38 //! #
  39 //! # #[cfg(feature = "std")]
  40 //! # fn build() -> Result<(), Bolt12ParseError> {
  41 //! let secp_ctx = Secp256k1::new();
  42 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
  43 //! let pubkey = PublicKey::from(keys);
  44 //!
  45 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
  46 //! let offer = OfferBuilder::new("coffee, large".to_string(), pubkey)
  47 //!     .amount_msats(20_000)
  48 //!     .supported_quantity(Quantity::Unbounded)
  49 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  50 //!     .issuer("Foo Bar".to_string())
  51 //!     .path(create_blinded_path())
  52 //!     .path(create_another_blinded_path())
  53 //!     .build()?;
  54 //!
  55 //! // Encode as a bech32 string for use in a QR code.
  56 //! let encoded_offer = offer.to_string();
  57 //!
  58 //! // Parse from a bech32 string after scanning from a QR code.
  59 //! let offer = encoded_offer.parse::<Offer>()?;
  60 //!
  61 //! // Encode offer as raw bytes.
  62 //! let mut bytes = Vec::new();
  63 //! offer.write(&mut bytes).unwrap();
  64 //!
  65 //! // Decode raw bytes into an offer.
  66 //! let offer = Offer::try_from(bytes)?;
  67 //! # Ok(())
  68 //! # }
  69 //! ```
  70 //!
  71 //! # Note
  72 //!
  73 //! If constructing an [`Offer`] for use with a [`ChannelManager`], use
  74 //! [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
  75 //!
  76 //! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  77 //! [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
  78
  79 use bitcoin::blockdata::constants::ChainHash;
  80 use bitcoin::network::constants::Network;
  81 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  82 use core::convert::TryFrom;
  83 use core::num::NonZeroU64;
  84 use core::ops::Deref;
  85 use core::str::FromStr;
  86 use core::time::Duration;
  87 use crate::sign::EntropySource;
  88 use crate::io;
  89 use crate::blinded_path::BlindedPath;
  90 use crate::ln::channelmanager::PaymentId;
  91 use crate::ln::features::OfferFeatures;
  92 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  93 use crate::ln::msgs::MAX_VALUE_MSAT;
  94 use crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder};
  95 use crate::offers::merkle::TlvStream;
  96 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
  97 use crate::offers::signer::{Metadata, MetadataMaterial, self};
  98 use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
  99 use crate::util::string::PrintableString;
 100
 101 use crate::prelude::*;
 102
 103 #[cfg(feature = "std")]
 104 use std::time::SystemTime;
 105
 106 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
 107
 108 /// Builds an [`Offer`] for the "offer to be paid" flow.
 109 ///
 110 /// See [module-level documentation] for usage.
 111 ///
 112 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 113 ///
 114 /// [module-level documentation]: self
 115 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
 116         offer: OfferContents,
 117         metadata_strategy: core::marker::PhantomData<M>,
 118         secp_ctx: Option<&'a Secp256k1<T>>,
 119 }
 120
 121 /// Builds an [`Offer`] for the "offer to be paid" flow.
 122 ///
 123 /// See [module-level documentation] for usage.
 124 ///
 125 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 126 ///
 127 /// [module-level documentation]: self
 128 #[cfg(c_bindings)]
 129 pub struct OfferWithExplicitMetadataBuilder<'a> {
 130         offer: OfferContents,
 131         metadata_strategy: core::marker::PhantomData<ExplicitMetadata>,
 132         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 133 }
 134
 135 /// Builds an [`Offer`] for the "offer to be paid" flow.
 136 ///
 137 /// See [module-level documentation] for usage.
 138 ///
 139 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 140 ///
 141 /// [module-level documentation]: self
 142 #[cfg(c_bindings)]
 143 pub struct OfferWithDerivedMetadataBuilder<'a> {
 144         offer: OfferContents,
 145         metadata_strategy: core::marker::PhantomData<DerivedMetadata>,
 146         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 147 }
 148
 149 /// Indicates how [`Offer::metadata`] may be set.
 150 ///
 151 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 152 pub trait MetadataStrategy {}
 153
 154 /// [`Offer::metadata`] may be explicitly set or left empty.
 155 ///
 156 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 157 pub struct ExplicitMetadata {}
 158
 159 /// [`Offer::metadata`] will be derived.
 160 ///
 161 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 162 pub struct DerivedMetadata {}
 163
 164 impl MetadataStrategy for ExplicitMetadata {}
 165
 166 impl MetadataStrategy for DerivedMetadata {}
 167
 168 macro_rules! offer_explicit_metadata_builder_methods { (
 169         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr
 170 ) => {
 171         /// Creates a new builder for an offer setting the [`Offer::description`] and using the
 172         /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
 173         /// while the offer is valid.
 174         ///
 175         /// Use a different pubkey per offer to avoid correlating offers.
 176         ///
 177         /// # Note
 178         ///
 179         /// If constructing an [`Offer`] for use with a [`ChannelManager`], use
 180         /// [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
 181         ///
 182         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 183         /// [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
 184         pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
 185                 Self {
 186                         offer: OfferContents {
 187                                 chains: None, metadata: None, amount: None, description,
 188                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 189                                 supported_quantity: Quantity::One, signing_pubkey,
 190                         },
 191                         metadata_strategy: core::marker::PhantomData,
 192                         secp_ctx: None,
 193                 }
 194         }
 195
 196         /// Sets the [`Offer::metadata`] to the given bytes.
 197         ///
 198         /// Successive calls to this method will override the previous setting.
 199         pub fn metadata(mut $self: $self_type, metadata: Vec<u8>) -> Result<$return_type, Bolt12SemanticError> {
 200                 $self.offer.metadata = Some(Metadata::Bytes(metadata));
 201                 Ok($return_value)
 202         }
 203 } }
 204
 205 macro_rules! offer_derived_metadata_builder_methods { ($secp_context: ty) => {
 206         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
 207         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
 208         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
 209         /// provided `node_id` is used for the signing pubkey.
 210         ///
 211         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
 212         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
 213         /// [`ExpandedKey`].
 214         ///
 215         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
 216         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 217         pub fn deriving_signing_pubkey<ES: Deref>(
 218                 description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 219                 secp_ctx: &'a Secp256k1<$secp_context>
 220         ) -> Self where ES::Target: EntropySource {
 221                 let nonce = Nonce::from_entropy_source(entropy_source);
 222                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
 223                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 224                 Self {
 225                         offer: OfferContents {
 226                                 chains: None, metadata: Some(metadata), amount: None, description,
 227                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 228                                 supported_quantity: Quantity::One, signing_pubkey: node_id,
 229                         },
 230                         metadata_strategy: core::marker::PhantomData,
 231                         secp_ctx: Some(secp_ctx),
 232                 }
 233         }
 234 } }
 235
 236 macro_rules! offer_builder_methods { (
 237         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 238 ) => {
 239         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 240         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 241         ///
 242         /// See [`Offer::chains`] on how this relates to the payment currency.
 243         ///
 244         /// Successive calls to this method will add another chain hash.
 245         pub fn chain($self: $self_type, network: Network) -> $return_type {
 246                 $self.chain_hash(ChainHash::using_genesis_block(network))
 247         }
 248
 249         /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
 250         /// [`Network::Bitcoin`] is assumed to be the only one supported.
 251         ///
 252         /// See [`Offer::chains`] on how this relates to the payment currency.
 253         ///
 254         /// Successive calls to this method will add another chain hash.
 255         pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> $return_type {
 256                 let chains = $self.offer.chains.get_or_insert_with(Vec::new);
 257                 if !chains.contains(&chain) {
 258                         chains.push(chain);
 259                 }
 260
 261                 $return_value
 262         }
 263
 264         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 265         ///
 266         /// Successive calls to this method will override the previous setting.
 267         pub fn amount_msats($self: $self_type, amount_msats: u64) -> $return_type {
 268                 $self.amount(Amount::Bitcoin { amount_msats })
 269         }
 270
 271         /// Sets the [`Offer::amount`].
 272         ///
 273         /// Successive calls to this method will override the previous setting.
 274         pub(super) fn amount($($self_mut)* $self: $self_type, amount: Amount) -> $return_type {
 275                 $self.offer.amount = Some(amount);
 276                 $return_value
 277         }
 278
 279         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 280         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 281         ///
 282         /// Successive calls to this method will override the previous setting.
 283         pub fn absolute_expiry($($self_mut)* $self: $self_type, absolute_expiry: Duration) -> $return_type {
 284                 $self.offer.absolute_expiry = Some(absolute_expiry);
 285                 $return_value
 286         }
 287
 288         /// Sets the [`Offer::issuer`].
 289         ///
 290         /// Successive calls to this method will override the previous setting.
 291         pub fn issuer($($self_mut)* $self: $self_type, issuer: String) -> $return_type {
 292                 $self.offer.issuer = Some(issuer);
 293                 $return_value
 294         }
 295
 296         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 297         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 298         ///
 299         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 300         /// adding duplicate paths.
 301         pub fn path($($self_mut)* $self: $self_type, path: BlindedPath) -> $return_type {
 302                 $self.offer.paths.get_or_insert_with(Vec::new).push(path);
 303                 $return_value
 304         }
 305
 306         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 307         /// [`Quantity::One`].
 308         ///
 309         /// Successive calls to this method will override the previous setting.
 310         pub fn supported_quantity($($self_mut)* $self: $self_type, quantity: Quantity) -> $return_type {
 311                 $self.offer.supported_quantity = quantity;
 312                 $return_value
 313         }
 314
 315         /// Builds an [`Offer`] from the builder's settings.
 316         pub fn build($($self_mut)* $self: $self_type) -> Result<Offer, Bolt12SemanticError> {
 317                 match $self.offer.amount {
 318                         Some(Amount::Bitcoin { amount_msats }) => {
 319                                 if amount_msats > MAX_VALUE_MSAT {
 320                                         return Err(Bolt12SemanticError::InvalidAmount);
 321                                 }
 322                         },
 323                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 324                         None => {},
 325                 }
 326
 327                 if let Some(chains) = &$self.offer.chains {
 328                         if chains.len() == 1 && chains[0] == $self.offer.implied_chain() {
 329                                 $self.offer.chains = None;
 330                         }
 331                 }
 332
 333                 Ok($self.build_without_checks())
 334         }
 335
 336         fn build_without_checks($($self_mut)* $self: $self_type) -> Offer {
 337                 // Create the metadata for stateless verification of an InvoiceRequest.
 338                 if let Some(mut metadata) = $self.offer.metadata.take() {
 339                         if metadata.has_derivation_material() {
 340                                 if $self.offer.paths.is_none() {
 341                                         metadata = metadata.without_keys();
 342                                 }
 343
 344                                 let mut tlv_stream = $self.offer.as_tlv_stream();
 345                                 debug_assert_eq!(tlv_stream.metadata, None);
 346                                 tlv_stream.metadata = None;
 347                                 if metadata.derives_recipient_keys() {
 348                                         tlv_stream.node_id = None;
 349                                 }
 350
 351                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
 352                                 metadata = derived_metadata;
 353                                 if let Some(keys) = keys {
 354                                         $self.offer.signing_pubkey = keys.public_key();
 355                                 }
 356                         }
 357
 358                         $self.offer.metadata = Some(metadata);
 359                 }
 360
 361                 let mut bytes = Vec::new();
 362                 $self.offer.write(&mut bytes).unwrap();
 363
 364                 Offer {
 365                         bytes,
 366                         #[cfg(not(c_bindings))]
 367                         contents: $self.offer,
 368                         #[cfg(c_bindings)]
 369                         contents: $self.offer.clone()
 370                 }
 371         }
 372 } }
 373
 374 #[cfg(test)]
 375 macro_rules! offer_builder_test_methods { (
 376         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 377 ) => {
 378         #[cfg_attr(c_bindings, allow(dead_code))]
 379         fn features_unchecked($($self_mut)* $self: $self_type, features: OfferFeatures) -> $return_type {
 380                 $self.offer.features = features;
 381                 $return_value
 382         }
 383
 384         #[cfg_attr(c_bindings, allow(dead_code))]
 385         pub(crate) fn clear_paths($($self_mut)* $self: $self_type) -> $return_type {
 386                 $self.offer.paths = None;
 387                 $return_value
 388         }
 389
 390         #[cfg_attr(c_bindings, allow(dead_code))]
 391         pub(super) fn build_unchecked($self: $self_type) -> Offer {
 392                 $self.build_without_checks()
 393         }
 394 } }
 395
 396 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 397         offer_builder_methods!(self, Self, Self, self, mut);
 398
 399         #[cfg(test)]
 400         offer_builder_test_methods!(self, Self, Self, self, mut);
 401 }
 402
 403 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
 404         offer_explicit_metadata_builder_methods!(self, Self, Self, self);
 405 }
 406
 407 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
 408         offer_derived_metadata_builder_methods!(T);
 409 }
 410
 411 #[cfg(all(c_bindings, not(test)))]
 412 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 413         offer_explicit_metadata_builder_methods!(self, &mut Self, (), ());
 414         offer_builder_methods!(self, &mut Self, (), ());
 415 }
 416
 417 #[cfg(all(c_bindings, test))]
 418 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 419         offer_explicit_metadata_builder_methods!(self, &mut Self, &mut Self, self);
 420         offer_builder_methods!(self, &mut Self, &mut Self, self);
 421         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 422 }
 423
 424 #[cfg(all(c_bindings, not(test)))]
 425 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 426         offer_derived_metadata_builder_methods!(secp256k1::All);
 427         offer_builder_methods!(self, &mut Self, (), ());
 428 }
 429
 430 #[cfg(all(c_bindings, test))]
 431 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 432         offer_derived_metadata_builder_methods!(secp256k1::All);
 433         offer_builder_methods!(self, &mut Self, &mut Self, self);
 434         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 435 }
 436
 437 #[cfg(c_bindings)]
 438 impl<'a> From<OfferBuilder<'a, DerivedMetadata, secp256k1::All>>
 439 for OfferWithDerivedMetadataBuilder<'a> {
 440         fn from(builder: OfferBuilder<'a, DerivedMetadata, secp256k1::All>) -> Self {
 441                 let OfferBuilder { offer, metadata_strategy, secp_ctx } = builder;
 442
 443                 Self { offer, metadata_strategy, secp_ctx }
 444         }
 445 }
 446
 447 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 448 ///
 449 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 450 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 451 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 452 ///
 453 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 454 /// latter.
 455 ///
 456 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 457 ///
 458 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 459 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 460 #[derive(Clone, Debug)]
 461 #[cfg_attr(test, derive(PartialEq))]
 462 pub struct Offer {
 463         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 464         // fields.
 465         pub(super) bytes: Vec<u8>,
 466         pub(super) contents: OfferContents,
 467 }
 468
 469 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 470 /// [`Bolt12Invoice`].
 471 ///
 472 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 473 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 474 #[derive(Clone, Debug)]
 475 #[cfg_attr(test, derive(PartialEq))]
 476 pub(super) struct OfferContents {
 477         chains: Option<Vec<ChainHash>>,
 478         metadata: Option<Metadata>,
 479         amount: Option<Amount>,
 480         description: String,
 481         features: OfferFeatures,
 482         absolute_expiry: Option<Duration>,
 483         issuer: Option<String>,
 484         paths: Option<Vec<BlindedPath>>,
 485         supported_quantity: Quantity,
 486         signing_pubkey: PublicKey,
 487 }
 488
 489 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 490         // TODO: Return a slice once ChainHash has constants.
 491         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 492         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 493         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 494         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 495         /// for the selected chain.
 496         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 497                 $contents.chains()
 498         }
 499
 500         // TODO: Link to corresponding method in `InvoiceRequest`.
 501         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 502         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 503         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 504                 $contents.metadata()
 505         }
 506
 507         /// The minimum amount required for a successful payment of a single item.
 508         pub fn amount(&$self) -> Option<&$crate::offers::offer::Amount> {
 509                 $contents.amount()
 510         }
 511
 512         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 513         /// but with the caveat that it has not been verified in any way.
 514         pub fn description(&$self) -> $crate::util::string::PrintableString {
 515                 $contents.description()
 516         }
 517
 518         /// Features pertaining to the offer.
 519         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 520                 &$contents.features()
 521         }
 522
 523         /// Duration since the Unix epoch when an invoice should no longer be requested.
 524         ///
 525         /// If `None`, the offer does not expire.
 526         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 527                 $contents.absolute_expiry()
 528         }
 529
 530         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 531         /// displayed to the user but with the caveat that it has not been verified in any way.
 532         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 533                 $contents.issuer()
 534         }
 535
 536         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 537         /// recipient privacy by obfuscating its node id.
 538         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 539                 $contents.paths()
 540         }
 541
 542         /// The quantity of items supported.
 543         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 544                 $contents.supported_quantity()
 545         }
 546
 547         /// The public key used by the recipient to sign invoices.
 548         pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
 549                 $contents.signing_pubkey()
 550         }
 551 } }
 552
 553 impl Offer {
 554         offer_accessors!(self, self.contents);
 555
 556         pub(super) fn implied_chain(&self) -> ChainHash {
 557                 self.contents.implied_chain()
 558         }
 559
 560         /// Returns whether the given chain is supported by the offer.
 561         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 562                 self.contents.supports_chain(chain)
 563         }
 564
 565         /// Whether the offer has expired.
 566         #[cfg(feature = "std")]
 567         pub fn is_expired(&self) -> bool {
 568                 self.contents.is_expired()
 569         }
 570
 571         /// Whether the offer has expired given the duration since the Unix epoch.
 572         pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 573                 self.contents.is_expired_no_std(duration_since_epoch)
 574         }
 575
 576         /// Returns whether the given quantity is valid for the offer.
 577         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 578                 self.contents.is_valid_quantity(quantity)
 579         }
 580
 581         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 582         ///
 583         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 584         pub fn expects_quantity(&self) -> bool {
 585                 self.contents.expects_quantity()
 586         }
 587
 588         /// Similar to [`Offer::request_invoice`] except it:
 589         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 590         ///   request,
 591         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 592         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 593         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 594         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 595         ///   be used when sending the payment for the requested invoice.
 596         ///
 597         /// Useful to protect the sender's privacy.
 598         ///
 599         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 600         ///
 601         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 602         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 603         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 604         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 605         pub fn request_invoice_deriving_payer_id<'a, 'b, ES: Deref, T: secp256k1::Signing>(
 606                 &'a self, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>,
 607                 payment_id: PaymentId
 608         ) -> Result<InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>, Bolt12SemanticError>
 609         where
 610                 ES::Target: EntropySource,
 611         {
 612                 if self.offer_features().requires_unknown_bits() {
 613                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 614                 }
 615
 616                 Ok(InvoiceRequestBuilder::deriving_payer_id(
 617                         self, expanded_key, entropy_source, secp_ctx, payment_id
 618                 ))
 619         }
 620
 621         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 622         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 623         ///
 624         /// Useful for recurring payments using the same `payer_id` with different invoices.
 625         ///
 626         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 627         ///
 628         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 629         pub fn request_invoice_deriving_metadata<ES: Deref>(
 630                 &self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 631                 payment_id: PaymentId
 632         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError>
 633         where
 634                 ES::Target: EntropySource,
 635         {
 636                 if self.offer_features().requires_unknown_bits() {
 637                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 638                 }
 639
 640                 Ok(InvoiceRequestBuilder::deriving_metadata(
 641                         self, payer_id, expanded_key, entropy_source, payment_id
 642                 ))
 643         }
 644
 645         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 646         /// which will be reflected in the `Bolt12Invoice` response.
 647         ///
 648         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 649         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 650         /// hashing in the signature calculation.
 651         ///
 652         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 653         /// Otherwise, payments may be correlated.
 654         ///
 655         /// Errors if the offer contains unknown required features.
 656         ///
 657         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 658         ///
 659         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 660         pub fn request_invoice(
 661                 &self, metadata: Vec<u8>, payer_id: PublicKey
 662         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, Bolt12SemanticError> {
 663                 if self.offer_features().requires_unknown_bits() {
 664                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 665                 }
 666
 667                 Ok(InvoiceRequestBuilder::new(self, metadata, payer_id))
 668         }
 669
 670         #[cfg(test)]
 671         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 672                 self.contents.as_tlv_stream()
 673         }
 674 }
 675
 676 impl AsRef<[u8]> for Offer {
 677         fn as_ref(&self) -> &[u8] {
 678                 &self.bytes
 679         }
 680 }
 681
 682 impl OfferContents {
 683         pub fn chains(&self) -> Vec<ChainHash> {
 684                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 685         }
 686
 687         pub fn implied_chain(&self) -> ChainHash {
 688                 ChainHash::using_genesis_block(Network::Bitcoin)
 689         }
 690
 691         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 692                 self.chains().contains(&chain)
 693         }
 694
 695         pub fn metadata(&self) -> Option<&Vec<u8>> {
 696                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 697         }
 698
 699         pub fn amount(&self) -> Option<&Amount> {
 700                 self.amount.as_ref()
 701         }
 702
 703         pub fn description(&self) -> PrintableString {
 704                 PrintableString(&self.description)
 705         }
 706
 707         pub fn features(&self) -> &OfferFeatures {
 708                 &self.features
 709         }
 710
 711         pub fn absolute_expiry(&self) -> Option<Duration> {
 712                 self.absolute_expiry
 713         }
 714
 715         #[cfg(feature = "std")]
 716         pub(super) fn is_expired(&self) -> bool {
 717                 SystemTime::UNIX_EPOCH
 718                         .elapsed()
 719                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 720                         .unwrap_or(false)
 721         }
 722
 723         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 724                 self.absolute_expiry
 725                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 726                         .unwrap_or(false)
 727         }
 728
 729         pub fn issuer(&self) -> Option<PrintableString> {
 730                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 731         }
 732
 733         pub fn paths(&self) -> &[BlindedPath] {
 734                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 735         }
 736
 737         pub(super) fn check_amount_msats_for_quantity(
 738                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 739         ) -> Result<(), Bolt12SemanticError> {
 740                 let offer_amount_msats = match self.amount {
 741                         None => 0,
 742                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 743                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 744                 };
 745
 746                 if !self.expects_quantity() || quantity.is_some() {
 747                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 748                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 749                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 750
 751                         if amount_msats < expected_amount_msats {
 752                                 return Err(Bolt12SemanticError::InsufficientAmount);
 753                         }
 754
 755                         if amount_msats > MAX_VALUE_MSAT {
 756                                 return Err(Bolt12SemanticError::InvalidAmount);
 757                         }
 758                 }
 759
 760                 Ok(())
 761         }
 762
 763         pub fn supported_quantity(&self) -> Quantity {
 764                 self.supported_quantity
 765         }
 766
 767         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 768                 let expects_quantity = self.expects_quantity();
 769                 match quantity {
 770                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 771                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 772                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 773                                 Err(Bolt12SemanticError::InvalidQuantity)
 774                         },
 775                         _ => Ok(()),
 776                 }
 777         }
 778
 779         fn is_valid_quantity(&self, quantity: u64) -> bool {
 780                 match self.supported_quantity {
 781                         Quantity::Bounded(n) => quantity <= n.get(),
 782                         Quantity::Unbounded => quantity > 0,
 783                         Quantity::One => quantity == 1,
 784                 }
 785         }
 786
 787         fn expects_quantity(&self) -> bool {
 788                 match self.supported_quantity {
 789                         Quantity::Bounded(_) => true,
 790                         Quantity::Unbounded => true,
 791                         Quantity::One => false,
 792                 }
 793         }
 794
 795         pub(super) fn signing_pubkey(&self) -> PublicKey {
 796                 self.signing_pubkey
 797         }
 798
 799         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 800         pub(super) fn verify<T: secp256k1::Signing>(
 801                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 802         ) -> Result<Option<KeyPair>, ()> {
 803                 match self.metadata() {
 804                         Some(metadata) => {
 805                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 806                                         match record.r#type {
 807                                                 OFFER_METADATA_TYPE => false,
 808                                                 OFFER_NODE_ID_TYPE => {
 809                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 810                                                 },
 811                                                 _ => true,
 812                                         }
 813                                 });
 814                                 signer::verify_recipient_metadata(
 815                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
 816                                 )
 817                         },
 818                         None => Err(()),
 819                 }
 820         }
 821
 822         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 823                 let (currency, amount) = match &self.amount {
 824                         None => (None, None),
 825                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 826                         Some(Amount::Currency { iso4217_code, amount }) => (
 827                                 Some(iso4217_code), Some(*amount)
 828                         ),
 829                 };
 830
 831                 let features = {
 832                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 833                 };
 834
 835                 OfferTlvStreamRef {
 836                         chains: self.chains.as_ref(),
 837                         metadata: self.metadata(),
 838                         currency,
 839                         amount,
 840                         description: Some(&self.description),
 841                         features,
 842                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 843                         paths: self.paths.as_ref(),
 844                         issuer: self.issuer.as_ref(),
 845                         quantity_max: self.supported_quantity.to_tlv_record(),
 846                         node_id: Some(&self.signing_pubkey),
 847                 }
 848         }
 849 }
 850
 851 impl Writeable for Offer {
 852         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 853                 WithoutLength(&self.bytes).write(writer)
 854         }
 855 }
 856
 857 impl Writeable for OfferContents {
 858         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 859                 self.as_tlv_stream().write(writer)
 860         }
 861 }
 862
 863 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 864 /// another currency.
 865 #[derive(Clone, Debug, PartialEq)]
 866 pub enum Amount {
 867         /// An amount of bitcoin.
 868         Bitcoin {
 869                 /// The amount in millisatoshi.
 870                 amount_msats: u64,
 871         },
 872         /// An amount of currency specified using ISO 4712.
 873         Currency {
 874                 /// The currency that the amount is denominated in.
 875                 iso4217_code: CurrencyCode,
 876                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 877                 amount: u64,
 878         },
 879 }
 880
 881 /// An ISO 4712 three-letter currency code (e.g., USD).
 882 pub type CurrencyCode = [u8; 3];
 883
 884 /// Quantity of items supported by an [`Offer`].
 885 #[derive(Clone, Copy, Debug, PartialEq)]
 886 pub enum Quantity {
 887         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
 888         /// but is limited (e.g., because of per customer or inventory limits).
 889         ///
 890         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
 891         /// is supported.
 892         Bounded(NonZeroU64),
 893         /// One or more items. Use when more than one item can be requested without any limit.
 894         Unbounded,
 895         /// Only one item. Use when only a single item can be requested.
 896         One,
 897 }
 898
 899 impl Quantity {
 900         fn to_tlv_record(&self) -> Option<u64> {
 901                 match self {
 902                         Quantity::Bounded(n) => Some(n.get()),
 903                         Quantity::Unbounded => Some(0),
 904                         Quantity::One => None,
 905                 }
 906         }
 907 }
 908
 909 /// Valid type range for offer TLV records.
 910 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
 911
 912 /// TLV record type for [`Offer::metadata`].
 913 const OFFER_METADATA_TYPE: u64 = 4;
 914
 915 /// TLV record type for [`Offer::signing_pubkey`].
 916 const OFFER_NODE_ID_TYPE: u64 = 22;
 917
 918 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
 919         (2, chains: (Vec<ChainHash>, WithoutLength)),
 920         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
 921         (6, currency: CurrencyCode),
 922         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 923         (10, description: (String, WithoutLength)),
 924         (12, features: (OfferFeatures, WithoutLength)),
 925         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 926         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 927         (18, issuer: (String, WithoutLength)),
 928         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 929         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
 930 });
 931
 932 impl Bech32Encode for Offer {
 933         const BECH32_HRP: &'static str = "lno";
 934 }
 935
 936 impl FromStr for Offer {
 937         type Err = Bolt12ParseError;
 938
 939         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 940                 Self::from_bech32_str(s)
 941         }
 942 }
 943
 944 impl TryFrom<Vec<u8>> for Offer {
 945         type Error = Bolt12ParseError;
 946
 947         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 948                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
 949                 let ParsedMessage { bytes, tlv_stream } = offer;
 950                 let contents = OfferContents::try_from(tlv_stream)?;
 951                 Ok(Offer { bytes, contents })
 952         }
 953 }
 954
 955 impl TryFrom<OfferTlvStream> for OfferContents {
 956         type Error = Bolt12SemanticError;
 957
 958         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 959                 let OfferTlvStream {
 960                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 961                         issuer, quantity_max, node_id,
 962                 } = tlv_stream;
 963
 964                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
 965
 966                 let amount = match (currency, amount) {
 967                         (None, None) => None,
 968                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
 969                                 return Err(Bolt12SemanticError::InvalidAmount);
 970                         },
 971                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 972                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
 973                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
 974                 };
 975
 976                 let description = match description {
 977                         None => return Err(Bolt12SemanticError::MissingDescription),
 978                         Some(description) => description,
 979                 };
 980
 981                 let features = features.unwrap_or_else(OfferFeatures::empty);
 982
 983                 let absolute_expiry = absolute_expiry
 984                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
 985
 986                 let supported_quantity = match quantity_max {
 987                         None => Quantity::One,
 988                         Some(0) => Quantity::Unbounded,
 989                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
 990                 };
 991
 992                 let signing_pubkey = match node_id {
 993                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 994                         Some(node_id) => node_id,
 995                 };
 996
 997                 Ok(OfferContents {
 998                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
 999                         supported_quantity, signing_pubkey,
1000                 })
1001         }
1002 }
1003
1004 impl core::fmt::Display for Offer {
1005         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1006                 self.fmt_bech32_str(f)
1007         }
1008 }
1009
1010 #[cfg(test)]
1011 mod tests {
1012         use super::{Amount, Offer, OfferTlvStreamRef, Quantity};
1013         #[cfg(not(c_bindings))]
1014         use {
1015                 super::OfferBuilder,
1016         };
1017         #[cfg(c_bindings)]
1018         use {
1019                 super::OfferWithExplicitMetadataBuilder as OfferBuilder,
1020         };
1021
1022         use bitcoin::blockdata::constants::ChainHash;
1023         use bitcoin::network::constants::Network;
1024         use bitcoin::secp256k1::Secp256k1;
1025         use core::convert::TryFrom;
1026         use core::num::NonZeroU64;
1027         use core::time::Duration;
1028         use crate::blinded_path::{BlindedHop, BlindedPath};
1029         use crate::sign::KeyMaterial;
1030         use crate::ln::features::OfferFeatures;
1031         use crate::ln::inbound_payment::ExpandedKey;
1032         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1033         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1034         use crate::offers::test_utils::*;
1035         use crate::util::ser::{BigSize, Writeable};
1036         use crate::util::string::PrintableString;
1037
1038         #[test]
1039         fn builds_offer_with_defaults() {
1040                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1041
1042                 let mut buffer = Vec::new();
1043                 offer.write(&mut buffer).unwrap();
1044
1045                 assert_eq!(offer.bytes, buffer.as_slice());
1046                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1047                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
1048                 assert_eq!(offer.metadata(), None);
1049                 assert_eq!(offer.amount(), None);
1050                 assert_eq!(offer.description(), PrintableString("foo"));
1051                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1052                 assert_eq!(offer.absolute_expiry(), None);
1053                 #[cfg(feature = "std")]
1054                 assert!(!offer.is_expired());
1055                 assert_eq!(offer.paths(), &[]);
1056                 assert_eq!(offer.issuer(), None);
1057                 assert_eq!(offer.supported_quantity(), Quantity::One);
1058                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1059
1060                 assert_eq!(
1061                         offer.as_tlv_stream(),
1062                         OfferTlvStreamRef {
1063                                 chains: None,
1064                                 metadata: None,
1065                                 currency: None,
1066                                 amount: None,
1067                                 description: Some(&String::from("foo")),
1068                                 features: None,
1069                                 absolute_expiry: None,
1070                                 paths: None,
1071                                 issuer: None,
1072                                 quantity_max: None,
1073                                 node_id: Some(&pubkey(42)),
1074                         },
1075                 );
1076
1077                 if let Err(e) = Offer::try_from(buffer) {
1078                         panic!("error parsing offer: {:?}", e);
1079                 }
1080         }
1081
1082         #[test]
1083         fn builds_offer_with_chains() {
1084                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1085                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1086
1087                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1088                         .chain(Network::Bitcoin)
1089                         .build()
1090                         .unwrap();
1091                 assert!(offer.supports_chain(mainnet));
1092                 assert_eq!(offer.chains(), vec![mainnet]);
1093                 assert_eq!(offer.as_tlv_stream().chains, None);
1094
1095                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1096                         .chain(Network::Testnet)
1097                         .build()
1098                         .unwrap();
1099                 assert!(offer.supports_chain(testnet));
1100                 assert_eq!(offer.chains(), vec![testnet]);
1101                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1102
1103                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1104                         .chain(Network::Testnet)
1105                         .chain(Network::Testnet)
1106                         .build()
1107                         .unwrap();
1108                 assert!(offer.supports_chain(testnet));
1109                 assert_eq!(offer.chains(), vec![testnet]);
1110                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1111
1112                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1113                         .chain(Network::Bitcoin)
1114                         .chain(Network::Testnet)
1115                         .build()
1116                         .unwrap();
1117                 assert!(offer.supports_chain(mainnet));
1118                 assert!(offer.supports_chain(testnet));
1119                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1120                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1121         }
1122
1123         #[test]
1124         fn builds_offer_with_metadata() {
1125                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1126                         .metadata(vec![42; 32]).unwrap()
1127                         .build()
1128                         .unwrap();
1129                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1130                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1131
1132                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1133                         .metadata(vec![42; 32]).unwrap()
1134                         .metadata(vec![43; 32]).unwrap()
1135                         .build()
1136                         .unwrap();
1137                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1138                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1139         }
1140
1141         #[test]
1142         fn builds_offer_with_metadata_derived() {
1143                 let desc = "foo".to_string();
1144                 let node_id = recipient_pubkey();
1145                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1146                 let entropy = FixedEntropy {};
1147                 let secp_ctx = Secp256k1::new();
1148
1149                 #[cfg(c_bindings)]
1150                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1151                 let offer = OfferBuilder
1152                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1153                         .amount_msats(1000)
1154                         .build().unwrap();
1155                 assert_eq!(offer.signing_pubkey(), node_id);
1156
1157                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1158                         .build().unwrap()
1159                         .sign(payer_sign).unwrap();
1160                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1161
1162                 // Fails verification with altered offer field
1163                 let mut tlv_stream = offer.as_tlv_stream();
1164                 tlv_stream.amount = Some(100);
1165
1166                 let mut encoded_offer = Vec::new();
1167                 tlv_stream.write(&mut encoded_offer).unwrap();
1168
1169                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1170                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1171                         .build().unwrap()
1172                         .sign(payer_sign).unwrap();
1173                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1174
1175                 // Fails verification with altered metadata
1176                 let mut tlv_stream = offer.as_tlv_stream();
1177                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1178                 tlv_stream.metadata = Some(&metadata);
1179
1180                 let mut encoded_offer = Vec::new();
1181                 tlv_stream.write(&mut encoded_offer).unwrap();
1182
1183                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1184                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1185                         .build().unwrap()
1186                         .sign(payer_sign).unwrap();
1187                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1188         }
1189
1190         #[test]
1191         fn builds_offer_with_derived_signing_pubkey() {
1192                 let desc = "foo".to_string();
1193                 let node_id = recipient_pubkey();
1194                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1195                 let entropy = FixedEntropy {};
1196                 let secp_ctx = Secp256k1::new();
1197
1198                 let blinded_path = BlindedPath {
1199                         introduction_node_id: pubkey(40),
1200                         blinding_point: pubkey(41),
1201                         blinded_hops: vec![
1202                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1203                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1204                         ],
1205                 };
1206
1207                 #[cfg(c_bindings)]
1208                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1209                 let offer = OfferBuilder
1210                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1211                         .amount_msats(1000)
1212                         .path(blinded_path)
1213                         .build().unwrap();
1214                 assert_ne!(offer.signing_pubkey(), node_id);
1215
1216                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1217                         .build().unwrap()
1218                         .sign(payer_sign).unwrap();
1219                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1220
1221                 // Fails verification with altered offer field
1222                 let mut tlv_stream = offer.as_tlv_stream();
1223                 tlv_stream.amount = Some(100);
1224
1225                 let mut encoded_offer = Vec::new();
1226                 tlv_stream.write(&mut encoded_offer).unwrap();
1227
1228                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1229                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1230                         .build().unwrap()
1231                         .sign(payer_sign).unwrap();
1232                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1233
1234                 // Fails verification with altered signing pubkey
1235                 let mut tlv_stream = offer.as_tlv_stream();
1236                 let signing_pubkey = pubkey(1);
1237                 tlv_stream.node_id = Some(&signing_pubkey);
1238
1239                 let mut encoded_offer = Vec::new();
1240                 tlv_stream.write(&mut encoded_offer).unwrap();
1241
1242                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1243                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1244                         .build().unwrap()
1245                         .sign(payer_sign).unwrap();
1246                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1247         }
1248
1249         #[test]
1250         fn builds_offer_with_amount() {
1251                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1252                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1253
1254                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1255                         .amount_msats(1000)
1256                         .build()
1257                         .unwrap();
1258                 let tlv_stream = offer.as_tlv_stream();
1259                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1260                 assert_eq!(tlv_stream.amount, Some(1000));
1261                 assert_eq!(tlv_stream.currency, None);
1262
1263                 #[cfg(not(c_bindings))]
1264                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1265                         .amount(currency_amount.clone());
1266                 #[cfg(c_bindings)]
1267                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1268                 #[cfg(c_bindings)]
1269                 builder.amount(currency_amount.clone());
1270                 let tlv_stream = builder.offer.as_tlv_stream();
1271                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1272                 assert_eq!(tlv_stream.amount, Some(10));
1273                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1274                 match builder.build() {
1275                         Ok(_) => panic!("expected error"),
1276                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1277                 }
1278
1279                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1280                         .amount(currency_amount.clone())
1281                         .amount(bitcoin_amount.clone())
1282                         .build()
1283                         .unwrap();
1284                 let tlv_stream = offer.as_tlv_stream();
1285                 assert_eq!(tlv_stream.amount, Some(1000));
1286                 assert_eq!(tlv_stream.currency, None);
1287
1288                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1289                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1290                         Ok(_) => panic!("expected error"),
1291                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1292                 }
1293         }
1294
1295         #[test]
1296         fn builds_offer_with_features() {
1297                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1298                         .features_unchecked(OfferFeatures::unknown())
1299                         .build()
1300                         .unwrap();
1301                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1302                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1303
1304                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1305                         .features_unchecked(OfferFeatures::unknown())
1306                         .features_unchecked(OfferFeatures::empty())
1307                         .build()
1308                         .unwrap();
1309                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1310                 assert_eq!(offer.as_tlv_stream().features, None);
1311         }
1312
1313         #[test]
1314         fn builds_offer_with_absolute_expiry() {
1315                 let future_expiry = Duration::from_secs(u64::max_value());
1316                 let past_expiry = Duration::from_secs(0);
1317                 let now = future_expiry - Duration::from_secs(1_000);
1318
1319                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1320                         .absolute_expiry(future_expiry)
1321                         .build()
1322                         .unwrap();
1323                 #[cfg(feature = "std")]
1324                 assert!(!offer.is_expired());
1325                 assert!(!offer.is_expired_no_std(now));
1326                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1327                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1328
1329                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1330                         .absolute_expiry(future_expiry)
1331                         .absolute_expiry(past_expiry)
1332                         .build()
1333                         .unwrap();
1334                 #[cfg(feature = "std")]
1335                 assert!(offer.is_expired());
1336                 assert!(offer.is_expired_no_std(now));
1337                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1338                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1339         }
1340
1341         #[test]
1342         fn builds_offer_with_paths() {
1343                 let paths = vec![
1344                         BlindedPath {
1345                                 introduction_node_id: pubkey(40),
1346                                 blinding_point: pubkey(41),
1347                                 blinded_hops: vec![
1348                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1349                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1350                                 ],
1351                         },
1352                         BlindedPath {
1353                                 introduction_node_id: pubkey(40),
1354                                 blinding_point: pubkey(41),
1355                                 blinded_hops: vec![
1356                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1357                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1358                                 ],
1359                         },
1360                 ];
1361
1362                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1363                         .path(paths[0].clone())
1364                         .path(paths[1].clone())
1365                         .build()
1366                         .unwrap();
1367                 let tlv_stream = offer.as_tlv_stream();
1368                 assert_eq!(offer.paths(), paths.as_slice());
1369                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1370                 assert_ne!(pubkey(42), pubkey(44));
1371                 assert_eq!(tlv_stream.paths, Some(&paths));
1372                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1373         }
1374
1375         #[test]
1376         fn builds_offer_with_issuer() {
1377                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1378                         .issuer("bar".into())
1379                         .build()
1380                         .unwrap();
1381                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1382                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1383
1384                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1385                         .issuer("bar".into())
1386                         .issuer("baz".into())
1387                         .build()
1388                         .unwrap();
1389                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1390                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1391         }
1392
1393         #[test]
1394         fn builds_offer_with_supported_quantity() {
1395                 let one = NonZeroU64::new(1).unwrap();
1396                 let ten = NonZeroU64::new(10).unwrap();
1397
1398                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1399                         .supported_quantity(Quantity::One)
1400                         .build()
1401                         .unwrap();
1402                 let tlv_stream = offer.as_tlv_stream();
1403                 assert_eq!(offer.supported_quantity(), Quantity::One);
1404                 assert_eq!(tlv_stream.quantity_max, None);
1405
1406                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1407                         .supported_quantity(Quantity::Unbounded)
1408                         .build()
1409                         .unwrap();
1410                 let tlv_stream = offer.as_tlv_stream();
1411                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1412                 assert_eq!(tlv_stream.quantity_max, Some(0));
1413
1414                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1415                         .supported_quantity(Quantity::Bounded(ten))
1416                         .build()
1417                         .unwrap();
1418                 let tlv_stream = offer.as_tlv_stream();
1419                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1420                 assert_eq!(tlv_stream.quantity_max, Some(10));
1421
1422                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1423                         .supported_quantity(Quantity::Bounded(one))
1424                         .build()
1425                         .unwrap();
1426                 let tlv_stream = offer.as_tlv_stream();
1427                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1428                 assert_eq!(tlv_stream.quantity_max, Some(1));
1429
1430                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1431                         .supported_quantity(Quantity::Bounded(ten))
1432                         .supported_quantity(Quantity::One)
1433                         .build()
1434                         .unwrap();
1435                 let tlv_stream = offer.as_tlv_stream();
1436                 assert_eq!(offer.supported_quantity(), Quantity::One);
1437                 assert_eq!(tlv_stream.quantity_max, None);
1438         }
1439
1440         #[test]
1441         fn fails_requesting_invoice_with_unknown_required_features() {
1442                 match OfferBuilder::new("foo".into(), pubkey(42))
1443                         .features_unchecked(OfferFeatures::unknown())
1444                         .build().unwrap()
1445                         .request_invoice(vec![1; 32], pubkey(43))
1446                 {
1447                         Ok(_) => panic!("expected error"),
1448                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1449                 }
1450         }
1451
1452         #[test]
1453         fn parses_offer_with_chains() {
1454                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1455                         .chain(Network::Bitcoin)
1456                         .chain(Network::Testnet)
1457                         .build()
1458                         .unwrap();
1459                 if let Err(e) = offer.to_string().parse::<Offer>() {
1460                         panic!("error parsing offer: {:?}", e);
1461                 }
1462         }
1463
1464         #[test]
1465         fn parses_offer_with_amount() {
1466                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1467                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1468                         .build()
1469                         .unwrap();
1470                 if let Err(e) = offer.to_string().parse::<Offer>() {
1471                         panic!("error parsing offer: {:?}", e);
1472                 }
1473
1474                 let mut tlv_stream = offer.as_tlv_stream();
1475                 tlv_stream.amount = Some(1000);
1476                 tlv_stream.currency = Some(b"USD");
1477
1478                 let mut encoded_offer = Vec::new();
1479                 tlv_stream.write(&mut encoded_offer).unwrap();
1480
1481                 if let Err(e) = Offer::try_from(encoded_offer) {
1482                         panic!("error parsing offer: {:?}", e);
1483                 }
1484
1485                 let mut tlv_stream = offer.as_tlv_stream();
1486                 tlv_stream.amount = None;
1487                 tlv_stream.currency = Some(b"USD");
1488
1489                 let mut encoded_offer = Vec::new();
1490                 tlv_stream.write(&mut encoded_offer).unwrap();
1491
1492                 match Offer::try_from(encoded_offer) {
1493                         Ok(_) => panic!("expected error"),
1494                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1495                 }
1496
1497                 let mut tlv_stream = offer.as_tlv_stream();
1498                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1499                 tlv_stream.currency = None;
1500
1501                 let mut encoded_offer = Vec::new();
1502                 tlv_stream.write(&mut encoded_offer).unwrap();
1503
1504                 match Offer::try_from(encoded_offer) {
1505                         Ok(_) => panic!("expected error"),
1506                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1507                 }
1508         }
1509
1510         #[test]
1511         fn parses_offer_with_description() {
1512                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1513                 if let Err(e) = offer.to_string().parse::<Offer>() {
1514                         panic!("error parsing offer: {:?}", e);
1515                 }
1516
1517                 let mut tlv_stream = offer.as_tlv_stream();
1518                 tlv_stream.description = None;
1519
1520                 let mut encoded_offer = Vec::new();
1521                 tlv_stream.write(&mut encoded_offer).unwrap();
1522
1523                 match Offer::try_from(encoded_offer) {
1524                         Ok(_) => panic!("expected error"),
1525                         Err(e) => {
1526                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1527                         },
1528                 }
1529         }
1530
1531         #[test]
1532         fn parses_offer_with_paths() {
1533                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1534                         .path(BlindedPath {
1535                                 introduction_node_id: pubkey(40),
1536                                 blinding_point: pubkey(41),
1537                                 blinded_hops: vec![
1538                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1539                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1540                                 ],
1541                         })
1542                         .path(BlindedPath {
1543                                 introduction_node_id: pubkey(40),
1544                                 blinding_point: pubkey(41),
1545                                 blinded_hops: vec![
1546                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1547                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1548                                 ],
1549                         })
1550                         .build()
1551                         .unwrap();
1552                 if let Err(e) = offer.to_string().parse::<Offer>() {
1553                         panic!("error parsing offer: {:?}", e);
1554                 }
1555
1556                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1557                 builder.offer.paths = Some(vec![]);
1558
1559                 let offer = builder.build().unwrap();
1560                 if let Err(e) = offer.to_string().parse::<Offer>() {
1561                         panic!("error parsing offer: {:?}", e);
1562                 }
1563         }
1564
1565         #[test]
1566         fn parses_offer_with_quantity() {
1567                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1568                         .supported_quantity(Quantity::One)
1569                         .build()
1570                         .unwrap();
1571                 if let Err(e) = offer.to_string().parse::<Offer>() {
1572                         panic!("error parsing offer: {:?}", e);
1573                 }
1574
1575                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1576                         .supported_quantity(Quantity::Unbounded)
1577                         .build()
1578                         .unwrap();
1579                 if let Err(e) = offer.to_string().parse::<Offer>() {
1580                         panic!("error parsing offer: {:?}", e);
1581                 }
1582
1583                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1584                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1585                         .build()
1586                         .unwrap();
1587                 if let Err(e) = offer.to_string().parse::<Offer>() {
1588                         panic!("error parsing offer: {:?}", e);
1589                 }
1590
1591                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1592                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1593                         .build()
1594                         .unwrap();
1595                 if let Err(e) = offer.to_string().parse::<Offer>() {
1596                         panic!("error parsing offer: {:?}", e);
1597                 }
1598         }
1599
1600         #[test]
1601         fn parses_offer_with_node_id() {
1602                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1603                 if let Err(e) = offer.to_string().parse::<Offer>() {
1604                         panic!("error parsing offer: {:?}", e);
1605                 }
1606
1607                 let mut tlv_stream = offer.as_tlv_stream();
1608                 tlv_stream.node_id = None;
1609
1610                 let mut encoded_offer = Vec::new();
1611                 tlv_stream.write(&mut encoded_offer).unwrap();
1612
1613                 match Offer::try_from(encoded_offer) {
1614                         Ok(_) => panic!("expected error"),
1615                         Err(e) => {
1616                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1617                         },
1618                 }
1619         }
1620
1621         #[test]
1622         fn fails_parsing_offer_with_extra_tlv_records() {
1623                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1624
1625                 let mut encoded_offer = Vec::new();
1626                 offer.write(&mut encoded_offer).unwrap();
1627                 BigSize(80).write(&mut encoded_offer).unwrap();
1628                 BigSize(32).write(&mut encoded_offer).unwrap();
1629                 [42u8; 32].write(&mut encoded_offer).unwrap();
1630
1631                 match Offer::try_from(encoded_offer) {
1632                         Ok(_) => panic!("expected error"),
1633                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1634                 }
1635         }
1636 }
1637
1638 #[cfg(test)]
1639 mod bolt12_tests {
1640         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1641         use crate::ln::msgs::DecodeError;
1642
1643         #[test]
1644         fn parses_bech32_encoded_offers() {
1645                 let offers = [
1646                         // Minimal bolt12 offer
1647                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1648
1649                         // for testnet
1650                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1651
1652                         // for bitcoin (redundant)
1653                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1654
1655                         // for bitcoin or liquidv1
1656                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1657
1658                         // with metadata
1659                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1660
1661                         // with amount
1662                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1663
1664                         // with currency
1665                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1666
1667                         // with expiry
1668                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1669
1670                         // with issuer
1671                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1672
1673                         // with quantity
1674                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1675
1676                         // with unlimited (or unknown) quantity
1677                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1678
1679                         // with single quantity (weird but valid)
1680                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1681
1682                         // with feature
1683                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1684
1685                         // with blinded path via Bob (0x424242...), blinding 020202...
1686                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1687
1688                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1689                         "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",
1690
1691                         // unknown odd field
1692                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1693                 ];
1694                 for encoded_offer in &offers {
1695                         if let Err(e) = encoded_offer.parse::<Offer>() {
1696                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1697                         }
1698                 }
1699         }
1700
1701         #[test]
1702         fn fails_parsing_bech32_encoded_offers() {
1703                 // Malformed: fields out of order
1704                 assert_eq!(
1705                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1706                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1707                 );
1708
1709                 // Malformed: unknown even TLV type 78
1710                 assert_eq!(
1711                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1712                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1713                 );
1714
1715                 // Malformed: empty
1716                 assert_eq!(
1717                         "lno1".parse::<Offer>(),
1718                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1719                 );
1720
1721                 // Malformed: truncated at type
1722                 assert_eq!(
1723                         "lno1pg".parse::<Offer>(),
1724                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1725                 );
1726
1727                 // Malformed: truncated in length
1728                 assert_eq!(
1729                         "lno1pt7s".parse::<Offer>(),
1730                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1731                 );
1732
1733                 // Malformed: truncated after length
1734                 assert_eq!(
1735                         "lno1pgpq".parse::<Offer>(),
1736                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1737                 );
1738
1739                 // Malformed: truncated in description
1740                 assert_eq!(
1741                         "lno1pgpyz".parse::<Offer>(),
1742                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1743                 );
1744
1745                 // Malformed: invalid offer_chains length
1746                 assert_eq!(
1747                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1748                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1749                 );
1750
1751                 // Malformed: truncated currency UTF-8
1752                 assert_eq!(
1753                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1754                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1755                 );
1756
1757                 // Malformed: invalid currency UTF-8
1758                 assert_eq!(
1759                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1760                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1761                 );
1762
1763                 // Malformed: truncated description UTF-8
1764                 assert_eq!(
1765                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1766                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1767                 );
1768
1769                 // Malformed: invalid description UTF-8
1770                 assert_eq!(
1771                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1772                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1773                 );
1774
1775                 // Malformed: truncated offer_paths
1776                 assert_eq!(
1777                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1778                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1779                 );
1780
1781                 // Malformed: zero num_hops in blinded_path
1782                 assert_eq!(
1783                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1784                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1785                 );
1786
1787                 // Malformed: truncated onionmsg_hop in blinded_path
1788                 assert_eq!(
1789                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1790                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1791                 );
1792
1793                 // Malformed: bad first_node_id in blinded_path
1794                 assert_eq!(
1795                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1796                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1797                 );
1798
1799                 // Malformed: bad blinding in blinded_path
1800                 assert_eq!(
1801                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1802                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1803                 );
1804
1805                 // Malformed: bad blinded_node_id in onionmsg_hop
1806                 assert_eq!(
1807                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1808                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1809                 );
1810
1811                 // Malformed: truncated issuer UTF-8
1812                 assert_eq!(
1813                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1814                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1815                 );
1816
1817                 // Malformed: invalid issuer UTF-8
1818                 assert_eq!(
1819                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1820                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1821                 );
1822
1823                 // Malformed: invalid offer_node_id
1824                 assert_eq!(
1825                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
1826                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1827                 );
1828
1829                 // Contains type >= 80
1830                 assert_eq!(
1831                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1832                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1833                 );
1834
1835                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
1836                 // Contains unknown feature 22
1837                 assert!(
1838                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
1839                 );
1840
1841                 // Missing offer_description
1842                 assert_eq!(
1843                         "lno1zcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese".parse::<Offer>(),
1844                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1845                 );
1846
1847                 // Missing offer_node_id"
1848                 assert_eq!(
1849                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
1850                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1851                 );
1852         }
1853 }